Urinary ANGPTL3: A Novel Noninvasive Biomarker for Podocyte Injury in Pediatric Glomerular Diseases

Urinary ANGPTL3: A Novel Noninvasive Biomarker for Podocyte Injury in Pediatric Glomerular Diseases | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Urinary ANGPTL3: A Novel Noninvasive Biomarker for Podocyte Injury in Pediatric Glomerular Diseases Hengmin Wang, Jiaojiao Liu, Rufeng Dai, Chunyan Wang, Xiaotian Chen, and 7 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8459364/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 4 You are reading this latest preprint version Abstract Background: Podocyte injury is the pathological basis of various glomerular diseases, but noninvasive tools for assessing podocyte injury are still lacking at present. Angiopoietin-like protein 3 (ANGPTL3) has been proven to be pathologically elevated in glomerular diseases and associated with podocyte injury. The aim of this study was to evaluate the clinical utility of the urinary ANGPTL3-to-creatinine ratio (ANGPTL3/Cre) as a noninvasive biomarker for assessing podocyte injury in children with glomerular diseases. Methods: Renal ANGPTL3 expression was first examined in tissues from pediatric patients with podocyte injury (n=25) and controls (n=5), correlating it with established histological markers of podocyte injury and with urinary ANGPTL3 levels. Pediatric patients aged 1–18 years with glomerular diseases and healthy controls were subsequently enrolled and divided into a test set (n=346) and a validation set (n=150). ANGPTL3 levels in serum and urine were measured. Diagnostic performance was assessed using receiver operating characteristic (ROC) curves. Associations with podocyte injury and improvements in risk stratification were evaluated by logistic regression and reclassification improvement (NRI/IDI) analyses, respectively. Results: Renal ANGPTL3 expression correlated negatively with podocyte injury markers P57Kip2 ( r = -0.55, P = 0.002) and synaptopodin ( r = -0.37, P = 0.04) and positively with urinary ANGPTL3/Cre ( r = 0.64, P < 0.001). Urinary ANGPTL3/Cre was significantly elevated in patients with podocyte injury and served as an independent risk factor for this condition (OR = 7.66, 95% CI: 2.27-25.84, P = 0.001). It demonstrated superior diagnostic performance (area under the curve, AUC = 0.90 in both sets) compared to serum ANGPTL3 or traditional biomarkers. When combined with clinical variables, the AUC improved to 0.95 (95% CI: 0.93-0.97) with enhanced risk reclassification. High diagnostic efficacy (AUC = 0.88/0.86) was maintained even in patients with normal protein excretion. Conclusion: Urinary ANGPTL3/Cre is a reliable, noninvasive biomarker for podocyte injury in pediatric glomerular diseases. It effectively identifies subclinical injury in patients with normal protein excretion, showing strong potential for early screening and longitudinal monitoring. ANGPTL3 Glomerular Diseases Podocyte injury Biomarker Pediatric Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Key points Urinary ANGPTL3 is a robust, noninvasive indicator that is directly correlated with podocyte injury severity Urinary ANGPTL3 demonstrates superior diagnostic accuracy and significantly improves risk stratification over conventional biomarkers. Urinary ANGPTL3 demonstrates particular promise for detecting subclinical podocyte injury in patients with normalized proteinuria, addressing a critical unsatisfied clinical need. Introduction Glomerular diseases are major causes of chronic kidney disease (CKD) and are leading contributors to end-stage kidney disease (ESKD) worldwide 1 , 2 . Renal biopsy registry data indicate that primary glomerular diseases account for approximately 71% of all glomerular disease cases, imposing a heavy burden on healthcare in China 3 . The core pathological mechanism underlying these conditions, including primary diseases such as acute and chronic glomerulonephritis, primary nephrotic syndrome (PNS), IgA Nephropathy (IgA N); secondary diseases like lupus nephritis (LN), Henoch-Schönlein purpura nephritis (HSPN), and diabetic nephropathy (DN); and genetic diseases such as Alport syndrome, involves podocyte injury 4 . As terminally differentiated, nonrenewable components of the glomerular filtration barrier, podocytes are critical for preserving filtration integrity. Podocyte injury or loss triggers glomerular basement membrane (GBM) denudation and increased proteinuria, progressing to segmental or global glomerulosclerosis and ultimately leading to nephron loss and renal fibrosis. Thus, basic and clinical research targeting podocyte injury is indispensable for the prevention and management of CKD. Current diagnostic approaches for podocyte injury in glomerular diseases mainly rely on clinical biomarkers reflecting renal dysfunction and structural compromise, including measurements of blood urea nitrogen (UREA) and serum creatinine (CREA) levels, as well as qualitative and quantitative assessments of proteinuria 5 . While these methodologies are characterized by low cost and noninvasive nature, a definitive diagnosis of suspected podocyte injury still requires renal biopsy. Recently, novel biomarkers for kidney diseases have also shown great clinical application potential. For instance, nephrin, podocin, synaptopodin, podocalyxin, CD2AP, ACTN4 (which encodes actinin 4), PTPRO (which encodes GLEPP-1), and WT1 mRNA have been isolated from the urine of patients with different glomerular diseases 5 . Despite these advances, the lack of a reliable noninvasive biomarker for podocyte injury continues to hinder timely therapeutic intervention and dynamic monitoring of disease progression. ANGPTL3 predominantly originates from hepatocytes, with minimal expression detectable in renal tissue 6 . Initially characterized for its established roles in lipid metabolism and angiogenesis 7 , ANGPTL3 functions through the inhibition of lipoprotein lipase (LPL) and endothelial lipase (EL), consequently leading to increases in plasma triglyceride (TG) and very-low-density lipoprotein (VLDL) levels 8 – 10 . Accumulating evidence indicates that ANGPTL3 is also directly involved in podocyte pathophysiology. Our prior work demonstrated that elevated ANGPTL3 disrupts podocyte cytoskeletal integrity through specific signaling pathways, leading to foot process effacement and proteinuria 11 – 16 . Experimental studies have further shown that inhibiting ANGPTL3 expression attenuates podocyte injury and apoptosis 17 – 20 . Additionally, ANGPTL3 may indirectly potentiate renal injury through the induction of hyperlipidemia and inflammatory cascades 21 . Notably, both the genetic ablation of ANGPTL3 and therapeutic targeting of its FLD domain ameliorate podocyte injury in preclinical models, supporting the potential of ANGPTL3 as a therapeutic target 22 – 24 . Clinically, serum and urinary ANGPTL3 levels are correlated with disease severity in nephrotic syndrome and diabetic kidney disease, underscoring the translational relevance of ANGPTL3 11,25 . Despite these insights, whether urinary ANGPTL3/Cre can serve as a broadly applicable, noninvasive biomarker for podocyte injury across the spectrum of pediatric glomerular diseases remains unclear; moreover, its utility in patients without significant proteinuria, a clinically challenging subgroup, has not been systematically evaluated. On the base of this rationale, we hypothesize that urinary ANGPTL3/Cre reflects podocyte injury independent of proteinuria status and demonstrates superior diagnostic performance in pediatric glomerular diseases. The aim of this study was to validate the correlation of urinary ANGPTL3/Cre with histological injury, evaluate the diagnostic accuracy and independent predictive value of urinary ANGPTL3/Cre in a large clinical cohort, and establish the particular usefulness of urinary ANGPTL3/Cre in detecting subclinical podocyte damage in patients with normal urinary protein excretion. Methods Study Design In this two‑phase study, pediatric participants aged 0–18 years were enrolled from the Children’s Hospital of Fudan University between July 2023 and July 2025. Phase 1 (Pathological Cohort): This cohort included 25 children with glomerular diseases who underwent renal biopsy (kidney tissue collected during biopsy) and 5 children with renal tumors (adjacent normal kidney tissue obtained during surgical resection served as pathological controls). Phase 2 (Clinical Cohort): A total of 351 children with glomerular diseases and 145 healthy children (normal controls) were enrolled and allocated into a testing set and a validation set at a ratio of 7:3 at the time of enrollment. Participants enrolled from July 2023 to December 2024 were assigned to the test set, while those enrolled from January 2025 to July 2025 composed the validation set. Inclusion Criteria All participants in each study phase met the following corresponding criteria: Patients with glomerular diseases: The diagnosis was based on international consensus criteria. The spectrum of diseases included but was not limited to PNS, IgAN, HSPN, and LN. PNS was defined clinically, whereas all other subtypes required pathological confirmation via renal biopsy. Participants could present with or without proteinuria. Specimens were collected during either the acute or remission phase. Prior treatment with steroids or immunosuppressants, as well as no prior treatment, was allowed. Control Participants: Pathological Controls: Histologically normal kidney tissue was obtained from pediatric patients who underwent nephrectomy for renal tumors, with confirmed absence of glomerulopathy. Healthy Controls: Control children had no history or laboratory evidence of hepatic/renal dysfunction, proteinuria, or other systemic illnesses. Exclusion Criteria Participants in any phase were excluded if they met any of the following criteria: Severe cardiac, hepatic, or renal insufficiency; concurrent severe infection at enrollment (including but not limited to urinary or respiratory tract infections); history of kidney transplantation or long-term dialysis; comorbidities such as tumors, metabolic syndrome, obesity, familial hypercholesterolemia, fatty liver disease, or hypothyroidism; severe immune dysfunction; and congenital malformations or functional disorders (including systemic sclerosis, dermatomyositis, and congenital anomalies of the kidney and urinary tract [CAKUT]). Procedure All participants underwent blood tests in the morning after an overnight fast. Venous blood was obtained from the arm and collected in serum separator tubes. The samples were maintained at room temperature for 30 minutes and subsequently centrifuged at 2,000×g for 10 minutes at 4 °C to isolate serum. Mid-stream urine samples were collected in the morning using sterile containers, and centrifuged at 2,000 × g for 10 min at 4 °C. The resulting supernatants from both serum and urine were aliquoted into 1.5 ml tubes. All the samples were stored at -80 °C, and multiple thaw/freeze cycles were avoided. Immunohistochemical staining for ANGPTL3 Renal tissue paraffin sections (4 μm) were deparaffinized, subjected to antigen retrieval with EDTA (pH 9.0) at high temperature and pressure, and then treated with 3% H₂O₂ to block endogenous peroxidase activity. After blocking with 10% goat serum, the sections were incubated overnight at 4 °C with a primary antibody against ANGPTL3 (Thermo Fisher, MA5-35681, diluted 1:100). The sections were subsequently incubated at 37 °C for 45 min with a horseradish peroxidase-conjugated goat anti-rabbit secondary antibody (Abcam, ab205718, diluted 1:2000). Staining was visualized using DAB, and nuclei were counterstained with hematoxylin. Images were captured using an Olympus CX31 microscope, and the mean optical density of ANGPTL3 was analyzed with Image-Pro Plus 6.0 software. Immunofluorescence staining (dual-labeling of renal tissue) Following deparaffinization, antigen retrieval, and blocking, renal paraffin sections were sequentially incubated with an anti-P57Kip2 antibody (1:200), an HRP-conjugated goat anti-rabbit secondary antibody (1:4000), and CY5-tyramide working solution. After citrate-based antigen retrieval, the sections were then incubated with a primary antibody against Synaptopodin (1:100) and an Alexa Fluor ® 488-conjugated secondary antibody (1:400). Nuclei were counterstained with DAPI. Images were acquired using an Olympus BX53 fluorescence microscope coupled with a 3D HISTECH Pannoramic MIDI system. The mean fluorescence intensity of Synaptopodin and the number of P57-positive cells were quantified using Image-Pro Plus 6.0 software. Laboratory Measurements Urinary and serum ANGPTL3 levels were quantified using enzyme-Linked Immunosorbent Assay (ELISA) kits (serum ANGPTL3: ab254510, Abcam, Cambridge, UK; urinary ANGPTL3: SEKH0533, Solarbio, Beijing, China) in accordance with the manufacturers' instructions. All measurements were performed by personnel who were blinded to the patient data. The intra-assay and inter-assay coefficients of variation were both < 10%. Urinary creatinine levels were measured using a commercial assay kit (C0121, Njjcbio, Nanjing, China). Urinary ANGPTL3 concentrations were normalized to urinary creatinine levels and are expressed as ng/g creatinine. Other laboratory indicators, including 24-h urine total protein (24-h UTP), urinary protein quantitation (UPRO), urinary protein/creatinine ratio (UPCR), urinary red blood cells (URBC), serum albumin (ALB), UREA, CREA, total cholesterol (TC), TG, high-density lipoprotein (HDL), and VLDL, were measured using an autoanalyzer in the Department of Clinical Laboratory, Children's Hospital of Fudan University. Definitions 26–31 Podocyte injury: This condition encompasses a pathological continuum ranging from early, potentially reversible changes such as foot process effacement (FPE) and cytoskeletal rearrangement, to severe events including detachment from the GBM and apoptosis, ultimately culminating in irreversible podocyte depletion. In this study, podocyte injury was defined by the histological presence of FPE (confirmed by renal biopsy in all enrolled glomerular diseases except for PNS, which was clinically diagnosed). Nephrotic range proteinuria: UPCR ≥ 200 mg/mmol (2 mg/mg) in the first morning void or 24-h UTP ≥ 1000 mg/m 2 /d corresponding to 3+ or 4+ by urine dipstick Non-Nephrotic Range Proteinuria: Protein reagent strip result ≥ 1+, with 0.2 < UPCR< 2 mg/mg or 24-h UTP < 1000 mg/m 2 /d. Normal protein excretion: Protein reagent strip result from negative to trace, with UPCR ≤ 0.2 mg/mg (all the subjects in the normal excretion group in this study were children posttreatment). In this study, patients with normal protein excretion were further categorized into two groups: Complete remission (CR): UPCR (based on first morning void or 24 h urine sample) ≤ 20 mg/mmol (0.2 mg/mg) or < 100 mg/m²/d, respectively, or negative or trace dipstick on three or more consecutive days. In addition to these features, complete remission included the resolution of hematuria, defined as < 5 RBCs/HPF. (In this study, all patients with NS achieved complete remission within 1 month, and the time to complete remission for patients with other disease types did not exceed 6 months.) Partial remission (PR): UPCR (based on the first morning void or 24 h urine sample) ≤ 20 mg/mmol (0.2 mg/mg) or < 100 mg/m²/d, respectively, or negative or trace dipstick on three or more consecutive days, with the presence of RBCs ≥ 5/HPF, and/or dysmorphic RBCs (acanthocytes), and/or RBC casts in a fresh spot urine sample. Clinical data collection Clinical data, such as sex, age, body mass index (BMI), clinical symptoms, therapeutic regimen, and urinary and blood biological parameters were collected during hospitalization. Statistical analyses Statistical analyses were performed using GraphPad Prism 9.0 (GraphPad Software Inc., La Jolla, CA, USA), SPSS 26.0 (IBM, Armonk, NY, USA), and R version 4.1.2 (The R Foundation for Statistical Computing, Vienna, Austria). The aim of this study was to evaluate the clinical utility of urinary ANGPTL3/Cre as a biomarker for podocyte injury in pediatric glomerular diseases and to determine the potential of urinary ANGPTL3/Cre as an independent risk factor. An additional aim of this study was to construct and validate predictive models that combine urinary ANGPTL3/Cre with clinical variables, and to assess the improvement of such models, compared with traditional clinical biomarkers or single ANGPTL3 indicators, in terms of diagnostic efficacy and risk reclassification. Data normality was assessed using the Shapiro–Wilk test. Normally distributed quantitative variables are summarized as the mean ± standard deviation (SD), wh ereas nonnormally distributed data are reported as the median with interquartile range (IQR). Student’s t-test was used to analyze the differential expression between two groups with normally distributed data, whereas the Mann‒Whitney U test was used to compare nonnormally distributed data between two groups.Multiple group comparisons were performed using one-way analysis of variance (ANOVA) for normally distributed variables and the Kruskal–Wallis test for nonnormally distributedvariables. The relationship between urinary ANGPTL3/Cre and podocyte injury was evaluated using Spearman correlation analysis. Univariate logistic regression analysis, multivariate logistic regression analysis, and LASSO regression analysis were employed to evaluate risk factors associated with glomerular diseases. To evaluate predictive efficacy, the AUC was used to compare the discriminative performance of different risk prediction models (models with clinical variables only, models with biomarkers only, and combined models of biomarkers and clinical variables), with the DeLong test applied to assess differences between AUCs. The optimal cutoff values were identified via the Youden index in the test set and then applied to the validation set. Against the model containing clinical variables alone as the reference, we used the net reclassification improvement (NRI) and integrated discrimination improvement (IDI) to evaluate the improvement in risk reclassification achieved by models that additionally incorporated ANGPTL3. Calibration curves were plotted to assess the agreement between the predicted probabilities and observed event rates. All the statistical tests were two-tailed, with a significance level set at P < 0.05. Results Urinary ANGPTL3/Cre is associated with podocyte injury in glomerular diseases Immunofluorescence analysis revealed fewer P57-positive podocytes (a podocyte marker) and lower synaptopodin fluorescence intensity (a marker of podocyte injury) in the glomerular disease group than in the control group. Immunohistochemistry revealed elevated glomerular ANGPTL3 expression in the disease group ( Figure 1A ). Quantitative analyses confirmed that the synaptopodin fluorescence intensity and P57- positive podocyte count were significantly lower whereas the mean glomerular ANGPTL3 optical density was significantly greater in the glomerular disease group (all P < 0.001; Figure 1B – 1D ). Correlation analyses revealed that the mean glomerular ANGPTL3 optical density was negatively correlated with the P57-positive podocyte count ( r = –0.55, P = 0.002) and the synaptopodin fluorescence intensity ( r = –0.37, P = 0.04); in contrast, it showed a strong positive correlation with urinary ANGPTL3/Cre ( r = 0.64, P < 0.001) and no correlation with serum ANGPTL3 levers ( r = 0.00, P = 0.99) ( Figure 1E – 1H ). The relevant baseline data are presented in Additional File 1 . Cohort Description A total of 646 pediatric patients with kidney diseases and healthy controls were initially recruited from the Children's Hospital of Fudan University for potential inclusion in the test set. After screening, 346 individuals were included in the final analysis. Similarly, for the validation set, 310 participants were initially recruited, of whom 150 were ultimately analyzed ( Figure 2 ). The proportions of healthy controls (29.8% vs. 28%) and patients with glomerular diseases (70.2% vs. 72.0%) were similar between the test and validation sets. The distribution of major disease subtypes was also largely consistent between the two sets, including IgA N (15.3% vs. 10.7%), NS (30.6% vs. 24.7%), HSPN (11.8% vs. 12.7%), and other diseases (12.4% vs. 24%). This consistent distribution pattern was similarly observed within the normal protein excretion subgroup ( Additional File 2 ). The baseline characteristics of all the enrolled participants are detailed in Additional File 3 . Data on 24‑h UTP were unavailable for healthy controls, as this test is not routinely performed in healthy pediatric screening. Patients with glomerular diseases were further stratified into three subgroups on the basis of proteinuria level: nephrotic range proteinuria, non‑nephrotic range proteinuria, and normal protein excretion. Their corresponding baseline characteristics are summarized separately for the test and validation sets in Additional File 4 . Overall, the baseline clinical and laboratory profiles were highly concordant between the validation set and the test set. Moreover, intergroup differences in UPRO, URBC, ALB, TC, TG, HDL, and VLDL reflected the characteristic clinical profile of glomerular diseases. ANGPTL3 Levels as Predictors of Podocyte Injury in Glomerular Disease In the test set, the serum ANGPTL3 concentration was 40.27 (24.51, 55.62) ng/ml in the control group and 63.99 (42.99, 103.75) ng/ml in the glomerular disease group ( Figure 3A; Table 1 ; P < 0.001). Urinary ANGPTL3/Cre was also significantly greater in the glomerular disease group [0.77 (0.27, 1.78) ng/g] than in the control group [0.09 (0.02, 0.28) ng/g] ( Figure 3B; Table 1 ; P < 0.001). These findings were robustly validated in the independent validation set, where both serum ANGPTL3 and urinary ANGPTL3/Cre remained significantly elevated in the glomerular disease group ( Figure 3C, 3D ; both P < 0.001). The consistent elevation of ANGPTL3 in serum and urine suggests its potential pathogenic role in podocyte injury among children with glomerular diseases. Subgroup analyses stratified by proteinuria status demonstrated that urinary ANGPTL3/Cre was persistently elevated in patients with podocyte injury compared with healthy controls across all proteinuria subgroups in the test set. Moreover, serum ANGPTL3 levels tended to decrease with increasing proteinuria severity. However, in the validation set, there was no statistically significant difference in serum ANGPTL3 levels between the normal protein excretion subgroup and the healthy control subgroup ( Additional File 5A, 5C ). Across both sets, urinary ANGPTL3/Cre levels remained elevated in children with podocyte injury relative to those in healthy controls, regardless of proteinuria status. Nonetheless, no significant differences in urinary ANGPTL3/Cre were detected among subgroups stratified by proteinuria excretion level ( Additional File 5B, 5D ). Urinary ANGPTL3/Cre as an Independent Risk Factor for Podocyte Injury in Glomerular Diseases To identify independent risk factors for podocyte injury in pediatric glomerular diseases, we implemented a sequential analytical strategy. Initial univariate analysis of the candidate variables revealed potential predictors of podocyte injury ( P < 0.1). Among these factors, urinary ANGPTL3/Cre was most strongly associated with podocyte injury severity (OR=13.30, 95% CI: 5.85–30.25, P < 0.001) ( Additional File 6 ). These predictors were subsequently analyzed using LASSO regression, which retained key variables for the final model ( Additional File 7 ). Multivariable logistic regression adjusted for confounders revealed that BMI, URBC, TG, and urinary ANGPTL3/Cre were independent risk factors, whereas the serum ALB concentration served as a protective factor. Notably, urinary ANGPTL3/Cre exhibited the greatest effect size, with each 1-unit increase corresponding to a 7.66-fold increase in the risk of significant podocyte injury (OR=7.66, 95% CI: 2.27–25.84, P = 0.001). Other significant factors included URBC (OR=1.06, P < 0.001), TG (OR=2.78, P = 0.020), BMI (OR=1.17, P = 0.023), and ALB (OR= 0.55, P < 0.001) ( Table 2 ). These findings establish urinary ANGPTL3/Cre as a prominent and independent risk factor for podocyte injury in pediatric glomerular diseases. Predictive Performance of Urinary ANGPTL3/Cre in the Early Diagnosis of Podocyte Injury in Glomerular Disease Urinary ANGPTL3/Cre demonstrated excellent diagnostic performance for podocyte injury in glomerular diseases, with AUC values of 0.90 (95% CI: 0.85–0.93) in the test set and 0.90 (95% CI: 0.84–0.95) in the validation set ( Figure 4A – 4B, Additional File 8 ). This diagnostic capability remained robust in patients with normal protein excretion (AUC=0.87/0.84) ( Figure 4C – 4D ). This robust diagnostic performance was consistent across all disease subtypes, with AUCs exceeding 0.80 in both sets for NS, IgA N, HSPN and other subtypes. Among patients with normal protein excretion, urinary ANGPTL3/Cre also exhibited strong diagnostic value across remission statuses, with AUCs of 0.92 in the test set and 0.87 in the validation set for PR and 0.84 in the test set and 0.77 in the validation set for CR ( Figure 5 ). Using the optimal cutoff value of 0.29 derived from the test set, urinary ANGPTL3/Cre had a sensitivity of 0.71, a specificity of 0.91, positive predictive value (PPV) of 0.95, and negative predictive value (NPV) of 0.57 for detecting podocyte injury. This performance profile was preserved in the validation set and across disease subtypes, with consistent sensitivity and stable specificity, confirming its broad applicability across diverse clinical presentations of podocyte injury ( Additional File 9, 10 ). Furthermore, urinary ANGPTL3/Cre significantly outperformed both serum ANGPTL3 (AUC = 0.76) and traditional biomarkers including UPRO, URBC, ALB, UREA, and CREA (all P < 0.05; DeLong test) ( Additional File 11 ). We subsequently constructed combined models by integrating urinary ANGPTL3/Cre and/or serum ANGPTL3 with three variable sets, including serum clinical variables (UREA + CREA + ALB), urinary clinical variables (URBC + UPRO), and predictor variables (URBC + ALB + TG + BMI, obtained through multivariate logistic regression screening). Compared with their corresponding base model, all the combined models showed improved diagnostic efficacy for podocyte injury, with distinct performance characteristics. The predictor variables combined model (urinary ANGPTL3/Cre + predictor variables) achieved favorable predictive performance with fewer variables (AUC = 0.93, 95% CI: 0.91–0.96). In contrast, the full-variable combined model (urinary ANGPTL3/Cre + serum ANGPTL3 + all clinical variables) showed optimal predictive performance (AUC = 0.95; 95% CI: 0.93–0.97). Notably, the urinary clinical variables combined model (urinary ANGPTL3/Cre + urinary clinical variables) demonstrated comparable predictive performance to that of the full-variable model, with an AUC of 0.95 (95% CI: 0.93–0.97) ( Figure 4A – 4B) . This predictive performance was retained in the subgroup of patients with normal protein excretion, where urinary ANGPTL3/Cre alone achieved AUCs of 0.87 (test set) and 0.84 (validation set) for podocyte injury. In this subgroup, the urinary clinical combined variables model (AUC = 0.89) demonstrated comparable performance to the full-variable combined model (AUC = 0.90) but required the fewest variables ( Figure 4A – 4B) . The calibration curves for the core models showed acceptable agreement between the predicted and observed probabilities in both sets ( Additional File 12 ). Effect of Urinary ANGPTL3/Cre on Risk Reclassification for Podocyte Injury To evaluate whether urinary ANGPTL3/Cre improves risk reclassification for podocyte injury, we analyzed the category-free NRI, NRI in progressors, NRI in non-progressors, and IDI in both the test and validation sets. The inclusion of urinary ANGPTL3/Cre generally improved risk reclassification in both sets, with urinary clinical variables combined model demonstrating the most notable performance. This model had the highest category-free NRI across the models, with values of 0.63 (95% CI: 0.48–0.78) in the test set and 0.58 (95% CI: 0.35–0.75) in the validation set. Moreover, it result in a significant positive improvement in NRI for progressors in the test set (0.07, 95% CI: 0.01–0.12), while maintaining a high NRI for non-progressors in both sets (0.57 and 0.56, respectively), highlighting its dual capacity to accurately identify individuals with podocyte injury and rule out healthy individuals ( Table 3 ). Further analysis of patients with podocyte injury but normal protein excretion revealed even greater improvement with urinary ANGPTL3/Cre. Specifically, the category-free NRI of the urinary clinical variables combined model reached 0.94 (95% CI: 0.67–1.18), which was substantially greater than that observed in the overall population. This model also yielded an NRI for progressors of 0.29 (95% CI: 0.08–0.50), an NRI for non-progressors of 0.64 (95% CI: 0.49–0.78), and an IDI of 0.35 (95% CI: 0.28–0.43). In this subgroup, the full-variable combined model exhibited optimal performance, achieving the highest category-free NRI (1.08, 95% CI: 0.82–1.32), NRI for progressors (0.42, 95% CI: 0.20–0.61), NRI for non-progressors (0.67, 95% CI: 0.50–0.81), and IDI (0.35, 95% CI: 0.27–0.42) ( Additional File 13 ). Nevertheless, the urinary clinical variables combined model represents a pragmatically superior choice for clinical translation because of its noninvasive profile and fewer required variables. Discussion This study systematically investigated the association between ANGPTL3 and podocyte injury in glomerular diseases, establishing for the first time that urinary ANGPTL3/Cre is a valuable non‑invasive biomarker with significant clinical potential. Our findings demonstrate that urinary ANGPTL3/Cre reflects the extent of podocyte injury and exhibits not only excellent diagnostic performance but also particular utility in clinical settings where conventional biomarkers are inadequate. This study established a direct link between glomerular ANGPTL3 expression and podocyte injury at the tissue level and validated urinary ANGPTL3/Cre as a noninvasive biomarker for such damage. Significantly elevated ANGPTL3 expression was observed in the glomerular disease group, showing a negative correlation with podocyte number and the podocyte functional marker synaptopodin. These findings suggest that local glomerular upregulation of ANGPTL3 may directly contribute to the pathological process of podocyte injury. Previous investigations have shown that ANGPTL3 can disrupt podocyte cytoskeletal integrity via the integrin αvβ3-FAK-PI3K-Rac1 pathway, leading to foot process effacement and proteinuria 15 . Our work substantially expands the pathological significance of ANGPTL3 beyond that of PNS 11 – 13 and DN 32 , further supporting its role as a common regulatory factor in podocyte injury. The strong positive correlation between glomerular ANGPTL3 and urinary ANGPTL3/Cre, coupled with the absence of correlation with serum ANGPTL3, indicates that urinary ANGPTL3/Cre more closely reflects local glomerular secretion and directly reflects renal pathological alterations of ANGPTL3. In contrast, serum ANGPTL3 may be influenced by systemic metabolic factors. This characteristic provides a crucial rationale for the non-invasive clinical assessment of podocyte injury. Urinary ANGPTL3/Cre demonstrated remarkable diagnostic efficacy for podocyte injury, with an AUC of 0.90, which significantly surpassed that of both serum ANGPTL3 and conventional biomarkers. This performance compares favorably with other reported urinary biomarkers, exceeding those for CD4 + T cells in ANCA-associated vasculitis (AUC = 0.88) 33 and podocyte mRNAs in diabetic nephropathy (AUC = 0.72) 34 , matching that of urinary nephrin (AUC = 0.90) 35 , and surpassing that of urinary CD80 (AUC = 0.83) 35 . Notably, urinary ANGPTL3/Cre maintains consistent diagnostic efficacy in patients with normal urinary protein excretion, while urinary nephrin shows restricted diagnostic performance in hypertensive nephropathy (AUC = 0.63) 37 . Although this subgroup included posttreatment patients, the observed increase in urinary ANGPTL3/Cre suggests that it may increase during early disease stages prior to the onset of proteinuria, offering a distinct advantage for the early detection of podocyte injury. Furthermore, its sustained increase during clinical remission likely reflects persistent subclinical podocyte injury or may indicate a biological predisposition to relapse. This ability to detect residual podocyte injury in the absence of proteinuria constitutes a unique advantage over conventional monitoring. In predictive modeling, a simple urinary model combining ANGPTL3/Cre, UPRO, and URBC achieved outstanding performance (AUC = 0.95), comparable to that of a complex model incorporating all serum and clinical variables. This urinary model maintained robust performance in the challenging normal protein excretion subgroup (AUC = 0.89) while delivering substantial net reclassification improvement (NRI = 0.94) and integrated discrimination improvement (IDI = 0.35). Although the full combination model showed marginally better metrics in this subgroup (AUC = 0.91, NRI = 1.08, IDI = 0.35), the urinary model exhibited superior clinical applicability because of its minimal variable set and completely noninvasive profile. This capacity for accurate, noninvasive diagnosis not only optimizes the clinical workflow and reduces costs but also provides a practical strategy for the early detection of podocyte injury. Multivariable logistic regression revealed that urinary ANGPTL3/Cre, URBC, ALB, TG, and BMI were independent factors associated with podocyte injury risk. These findings align with prior reports linking URBC, TG, and BMI to CKD progression 38 – 40 , and ALB to protection 41 . Among these factors, urinary ANGPTL3/Cre had the strongest association. In contrast, serum ANGPTL3 was not identified as an independent risk factor, underscoring the superior relevance of the urinary biomarker. ANGPTL3 may contribute to podocyte injury through multiple pathways. The first constitutes a direct injury pathway operating through the integrin αvβ3-FAK-PI3K-Rac1 signaling axis that disrupts podocyte cytoskeletal architecture. The second represents a lipid metabolism-dependent pathway in which the ANGPTL3-mediated inhibition of LPL and EL activity triggers an increase in triglycerides. Gao et al. confirmed that ANGPTL3 contributes to both proteinuria and hyperlipidemia in PNS. Furthermore, animal experiments have revealed that the role of ANGPTL3 in hyperlipidemic-induced renal injury is mediated by ACTN4 42 , a key podocyte cytoskeletal protein whose dysregulation leads to foot process effacement 43 . These discoveries correspond with fundamental CKD understanding that identifies lipotoxicity as crucial for disease progression, while K/DOQI guidelines specifically designate dyslipidemia as a CKD progression marker 44 . Substantial research has demonstrates that hyperlipidemia can induce endoplasmic reticulum (ER) stress, inflammatory responses, and excessive reactive oxygen species (ROS) generation, which directly damage renal structures 45 while simultaneously promoting lipid accumulation and functional-structural modifications across various renal cell types including podocytes, mesangial cells, and tubular elements 46 – 48 . The mechanistic spectrum of ANGPTL3 action appears increasingly complex. Previous studies have proposed that the inhibition of podocyte epithelial-mesenchymal transition (EMT) constitutes a novel mechanism through which ANGPTL3 knockout alleviates podocyte injury 49 – 51 . In AKI, ANGPTL3 knockdown diminishes podocyte apoptosis by modulating the ROS/GRP78 signaling pathway 52 . These mechanisms collectively form an intricate network through which ANGPTL3 mediates renal damage. In summary, in this study, urinary ANGPTL3/Cre was established as an effective biomarker for podocyte injury in clinical practice, the mechanistic understanding of ANGPTL3 as a critical node that links renal injury and metabolic dysregulation was advanced. Elevated urinary ANGPTL3/Cre indicates active podocyte injury and provides critical information beyond conventional biomarkers, especially in patients with low or normalized proteinuria. Notably, our team has developed an anti‑ANGPTL3‑FLD monoclonal antibody that significantly reduced proteinuria, podocyte apoptosis, ROS production, and mitochondrial fragmentation in a nephropathy model 22 , 53 , 54 . Furthermore, an anti‑ANGPTL3/IL‑22 bifunctional fusion protein improved both proteinuria and glucose metabolism in diabetic nephropathy while suppressing inflammation and fibrosis 24 . These findings provide a solid foundation for clinical translation of innovative biologics. To address the limitations of commercial assays encountered in this study, we are currently developing a high‑sensitivity detection kit based on this proprietary anti‑ANGPTL3‑FLD antibody. This study has several limitations. First, this was a single‑center, cross‑sectional investigation. Although the Children’s Hospital of Fudan University is a national pediatric medical center with patients from across the country, geographic selection bias may still exist. Second, urinary ANGPTL3/Cre was not longitudinally monitored during different disease states or treatment phases, and its potential for guiding relapse management or treatment adjustment remains unassessed. Third, associations with pathological severity across different glomerular disease subtypes were not addressed. Future research should proceed along three lines. First, multicenter, large‑sample cohort studies with external validation in collaboration with pediatric hospitals in other regions should be conducted. Second, prospective cohort studies tracking changes in ANGPTL3 levels in relation to glomerular disease outcomes will help clarify its prognostic utility. Third, subgroup analyses stratified by glomerular disease subtype and pathological severity are needed to explore how ANGPTL3 relates to disease‑specific pathological progression. Conclusions In summary, in this study, urinary ANGPTL3/Cre was identified as a noninvasive and independent risk factor closely associated with podocyte injury in pediatric glomerular diseases. It outperformed conventional biomarkers in terms of diagnostic efficacy and sensitively indicated subclinical podocyte injury even when proteinuria levels were normal. Moreover, this marker shows promise as a screening tool to guide targeted ANGPTL3 therapies, laying the groundwork for individualized treatment. As a noninvasive biomarker with both mechanistic relevance and translational potential, urinary ANGPTL3/Cre may reshape diagnostic and therapeutic strategies for glomerular diseases involving podocyte injury and ultimately improve clinical outcomes. Abbreviations 24-h UTP 24-h urine total protein ALB Albumin ANGPTL3 Angiopoietin-like protein 3 ANGPTL3/Cre ANGPTL3-to-creatinine ratio ANOVA One-way analysis of variance AUC Area under the curve CAKUT Congenital anomalies of the kidney and urinary tract CKD Chronic kidney disease CREA Creatinine DN Diabetic nephropathy EL Endothelial lipase ELISA Enzyme-Linked Immunosorbent Assay EMT Epithelial-mesenchymal transition ER Endoplasmic reticulum ESKD End-stage kidney disease FPE Foot process effacement GBM Glomerular basement membrane HDL High-density lipoprotein HSPN Henoch-Schönlein purpura nephritis IDI Integrated discrimination improvement IgA N IgA Nephropathy IQR Interquartile range LN Lupus nephritis LPL Lipoprotein lipase NRI Net reclassification improvement PNS Primary nephrotic syndrome ROC Receiver operating characteristic ROS Reactive oxygen species SD Standard deviation TC Total cholesterol TG Triglycerides UPCR Urinary protein/creatinine ratio UPRO Urinary protein quantitation URBC Urinary red blood cells UREA Urea nitrogen VLDL Very-low-density lipoprotein Declarations Data availability statement The de-identified datasets used and/or analysed during the current study are available from the corresponding author on reasonable request. Ethics approval and consent to participate This study was approved by the Research Ethics Committee of the Children’s Hospital of Fudan University (Approval No. (2021)-446) and conducted in accordance with the Declaration of Helsinki. Written informed consent was obtained from the legal guardians or next of kin of all participants. No personal identification information of participants was collected, and the shared datasets are de-identified to protect privacy. Consent for publication Not applicable. Competing interests The authors declare that they have no competing interests. Funding Shanghai Municipal Health Commission Program (2025ZZ2008, 202240280); Shanghai Municipal Science and Technology Major Project (2023SHZDZX02C09); Shanghai Municipal Science and Technology "Innovation Action Plan" Basic Research Field Project (23JC1401200); Author Contributions HX conceived the study, acquired funding, provided essential resources, and supervised the entire research process. HW, JL, and RD conducted the investigation, with HW and JL responsible for data curation. HW and XC designed the methodology and performed formal analysis. XW provided software support for data processing. QS and YZ contributed to resource provision and study supervision, and YZ also participated in funding acquisition. JLiu (Jialu Liu), XT, and XH participated in the study discussions and provided critical insights for result interpretation. HW † , JL † , and RD † drafted the original manuscript. † These authors contributed equally to this work and share the first authorship. All authors read and approved the final manuscript. Acknowledgments We acknowledge all investigators for their cooperation. References Chen CH, Wu HY, Wang CL, et al. Proteinuria as a therapeutic target in advanced chronic kidney disease: a retrospective multicenter cohort study. Sci Rep . 2016;6:26539. doi:10.1038/srep26539 Usui T, Kanda E, Iseki C, Iseki K, Kashihara N, Nangaku M. Observation period for changes in proteinuria and risk prediction of end-stage renal disease in general population. Nephrol Carlton Vic . 2018;23(9):821-829. doi:10.1111/nep.13093 Chen H, Tang Z, Zeng C, et al. Pathological demography of native patients in a nephrology center in China. Chin Med J (Engl) . 2003;116(9):1377-1381. Sethi S, Fervenza FC. Standardized classification and reporting of glomerulonephritis. Nephrol Dial Transplant Off Publ Eur Dial Transpl Assoc - Eur Ren Assoc . 2019;34(2):193-199. doi:10.1093/ndt/gfy220 Sekulic M, Pichler Sekulic S. A compendium of urinary biomarkers indicative of glomerular podocytopathy. Pathol Res Int . 2013;2013:782395. doi:10.1155/2013/782395 Kim I, Kwak HJ, Ahn JE, et al. Molecular cloning and characterization of a novel angiopoietin family protein, angiopoietin-3. FEBS Lett . 1999;443(3):353-356. doi:10.1016/s0014-5793(99)00008-3 Santulli G. Angiopoietin-like proteins: a comprehensive look. Front Endocrinol . 2014;5:4. doi:10.3389/fendo.2014.00004 Essalmani R, Susan-Resiga D, Chamberland A, et al. Furin is the primary in vivo convertase of angiopoietin-like 3 and endothelial lipase in hepatocytes. J Biol Chem . 2013;288(37):26410-26418. doi:10.1074/jbc.M113.501304 Liu J, Afroza H, Rader DJ, Jin W. Angiopoietin-like protein 3 inhibits lipoprotein lipase activity through enhancing its cleavage by proprotein convertases. J Biol Chem . 2010;285(36):27561-27570. doi:10.1074/jbc.M110.144279 Robciuc MR, Maranghi M, Lahikainen A, et al. Angptl3 deficiency is associated with increased insulin sensitivity, lipoprotein lipase activity, and decreased serum free fatty acids. Arterioscler Thromb Vasc Biol . 2013;33(7):1706-1713. doi:10.1161/ATVBAHA.113.301397 Wen F, Liu J, Dai R, et al. Angiopoietin-like protein 3: a novel potential biomarker for nephrotic syndrome in children. Front Pediatr . 2023;11:1113484. doi:10.3389/fped.2023.1113484 Liu J, Xu H, Dai R, et al. Potential function of angiopoietin-like protein 3 in hyperlipidemia of nephrotic syndrome. Chin J Nephrol . 2015;31(9):669-673. doi:10.3760/cma.j.issn.1001-7097.2015.09.006 Zhong F, Liu S, Li Y, et al. ANGPTL3 impacts proteinuria and hyperlipidemia in primary nephrotic syndrome. Lipids Health Dis . 2022;21(1):38. doi:10.1186/s12944-022-01632-y Liu J, Gao X, Zhai Y, et al. A novel role of angiopoietin-like-3 associated with podocyte injury. Pediatr Res . 2015;77(6):732-739. doi:10.1038/pr.2015.38 Gao X, Xu H, Liu H, Rao J, Li Y, Zha X. Angiopoietin-like protein 3 regulates the motility and permeability of podocytes by altering nephrin expression in vitro. Biochem Biophys Res Commun . 2010;399(1):31-36. doi:10.1016/j.bbrc.2010.07.027 Lin Y, Rao J, Zha XL, Xu H. Angiopoietin-like 3 induces podocyte F-actin rearrangement through integrin α(V)β₃/FAK/PI3K pathway-mediated Rac1 activation. Biomed Res Int . 2013;2013:135608. doi:10.1155/2013/135608 Dai R, Liu H, Han X, et al. Angiopoietin-like-3 knockout protects against glomerulosclerosis in murine adriamycin-induced nephropathy by attenuating podocyte loss. BMC Nephrol . 2019;20(1):185. doi:10.1186/s12882-019-1383-1 Dai R, Lin Y, Liu H, et al. A vital role for Angptl3 in the PAN-induced podocyte loss by affecting detachment and apoptosis in vitro. BMC Nephrol . 2015;16:38. doi:10.1186/s12882-015-0034-4 Ma Y, Liu J, Liu H, Han X, Sun L, Xu H. Podocyte protection by Angptl3 knockout via inhibiting ROS/GRP78 pathway in LPS-induced acute kidney injury. Int Immunopharmacol . 2022;105:108549. doi:10.1016/j.intimp.2022.108549 Ma Y, Chen Y, Xu H, Du N. The influence of angiopoietin-like protein 3 on macrophages polarization and its effect on the podocyte EMT in diabetic nephropathy. Front Immunol . 2023;14:1228399. doi:10.3389/fimmu.2023.1228399 Tamehri Zadeh SS, Toth PP, Shapiro MD, Surma S, Banach M. ANGPTL3 vital role in different kidney diseases. Current knowledge and future perspectives. Biomed Pharmacother Biomedecine Pharmacother . 2025;188:118189. doi:10.1016/j.biopha.2025.118189 Lv Q, Han X, Ni J, et al. Anti-ANGPTL3-FLD monoclonal antibody treatment ameliorates podocyte lesions through attenuating mitochondrial damage. Cell Death Dis . 2022;13(10):867. doi:10.1038/s41419-022-05313-7 Han X, Dai R, Zhai Y, et al. Anti-proteinuria effect of antibody against ANGPTL3 coil-coiled domain on adriamycin-induced nephropathy in mice. Biochem Biophys Res Commun . 2019;516(3):812-818. doi:10.1016/j.bbrc.2019.06.065 Ma Q, Hu X, Liu F, et al. A novel fusion protein consisting of anti-ANGPTL3 antibody and interleukin-22 ameliorates diabetic nephropathy in mice. Front Immunol . 2022;13:1011442. doi:10.3389/fimmu.2022.1011442 Azadi SM, Fadaei R, Omid-Shafaat R, Hosseini J, Moradi N. Elevated angiopoietin-like protein 3 serum levels in diabetic nephropathy patients and its association with renal function and lipid profile. BMC Nephrol . 2023;24(1):172. doi:10.1186/s12882-023-03214-1 Trautmann A, Vivarelli M, Samuel S, et al. IPNA clinical practice recommendations for the diagnosis and management of children with steroid-resistant nephrotic syndrome. Pediatr Nephrol Berl Ger . 2020;35(8):1529-1561. doi:10.1007/s00467-020-04519-1 Vivarelli M, Samuel S, Coppo R, et al. IPNA clinical practice recommendations for the diagnosis and management of children with IgA nephropathy and IgA vasculitis nephritis. Pediatr Nephrol . 2025;40(2):533-569. doi:10.1007/s00467-024-06502-6 Kidney Disease: Improving Global Outcomes (KDIGO) Lupus Nephritis Work Group. KDIGO 2024 clinical practice guideline for the management of LUPUS NEPHRITIS. Kidney Int . 2024;105(1S):S1-S69. doi:10.1016/j.kint.2023.09.002 Maliakkal JG, Hicks MJ, Michael M, et al. Renal survival in children with glomerulonephritis with crescents: a pediatric nephrology research consortium cohort study. J Clin Med . 2020;9(8):2385. doi:10.3390/jcm9082385 Xi L, Sun Y, Chen Y, Yang X, Su H, Ren X. Clinicopathological features and prognosis of IgA vasculitis nephritis with nephrotic-range proteinuria in children. Pediatr Nephrol . 2024;39(11):3241-3250. doi:10.1007/s00467-024-06441-2 Finn LS. Nephrotic syndrome throughout childhood: diagnosing podocytopathies from the womb to the dorm. Pediatr Dev Pathol . 2024;27(5):426-458. doi:10.1177/10935266241242669 Azadi SM, Fadaei R, Omid-Shafaat R, Hosseini J, Moradi N. Elevated angiopoietin-like protein 3 serum levels in diabetic nephropathy patients and its association with renal function and lipid profile. BMC Nephrol . 2023;24(1):172. doi:10.1186/s12882-023-03214-1 Prskalo L, Skopnik CM, Goerlich N, et al. Urinary CD4+ T cells predict renal relapse in ANCA-associated vasculitis. J Am Soc Nephrol JASN . 2024;35(4):483-494. doi:10.1681/ASN.0000000000000311 Fukuda A, Minakawa A, Kikuchi M, et al. Urinary podocyte mRNAs precede microalbuminuria as a progression risk marker in human type 2 diabetic nephropathy. Sci Rep . 2020;10:18209. doi:10.1038/s41598-020-75320-1 Mesfine BB, Vojisavljevic D, Kapoor R, Watson D, Kandasamy Y, Rudd D. Urinary nephrin—a potential marker of early glomerular injury: a systematic review and meta-analysis. J Nephrol . 2024;37(1):39-51. doi:10.1007/s40620-023-01585-0 Gonzalez Guerrico AM, Lieske J, Klee G, et al. Urinary CD80 discriminates among glomerular disease types and reflects disease activity. Kidney Int Rep . 2020;5(11):2021-2031. doi:10.1016/j.ekir.2020.08.001 Kostovska I, Tosheska Trajkovska K, Labudović D, Kostovski O. Urinary nephrin as an early biomarker of hypertensive nephropathy. Acta Clin Croat . 2023;62(4):635-643. doi:10.20471/acc.2023.62.04.8 Kaneko T, Kodani E, Fujii H, Nakamura H, Sasabe H, Tamura Y. High body mass index and triglyceride levels at health checkups increase the risk of new-onset chronic kidney disease and worsening renal function: the TAMA MED project-CKD. Clin Exp Nephrol . 2024;28(10):1016-1026. doi:10.1007/s10157-024-02507-5 Lin Z, Feng L, Zeng H, et al. Nomogram for the prediction of crescent formation in IgA nephropathy patients: a retrospective study. BMC Nephrol . 2023;24(1):262. doi:10.1186/s12882-023-03310-2 Zhu F, Gan W, Liu H, Chen W, Zeng X. Risk factors for renal progression in patients with CKD and coexisting COPD. Int Urol Nephrol . 2025;57(3):885-895. doi:10.1007/s11255-024-04227-x Cheng T, Wang X, Han Y, Hao J, Hu H, Hao L. The level of serum albumin is associated with renal prognosis and renal function decline in patients with chronic kidney disease. BMC Nephrol . 2023;24(1):57. doi:10.1186/s12882-023-03110-8 Gao X, Suo Y, Zhang M, et al. Angiopoietin-like protein 3 markedly enhanced in the hyperlipidemia related proteinuria. Lipids Health Dis . 2019;18(1):116. doi:10.1186/s12944-019-1052-1 Li G, Lu D, Wang J, et al. ANGPTL3 is involved in kidney injury in high-fat diet-fed mice by suppressing ACTN4 expression. Lipids Health Dis . 2022;21(1):90. doi:10.1186/s12944-022-01700-3 Kidney Disease Outcomes Quality Initiative (K/DOQI) Group. K/DOQI clinical practice guidelines for management of dyslipidemias in patients with kidney disease. Am J Kidney Dis Off J Natl Kidney Found . 2003;41(4 Suppl 3):I-IV, S1-91. Yang P, Xiao Y, Luo X, et al. Inflammatory stress promotes the development of obesity-related chronic kidney disease via CD36 in mice. J Lipid Res . 2017;58(7):1417-1427. doi:10.1194/jlr.M076216 de Vries APJ, Ruggenenti P, Ruan XZ, et al. Fatty kidney: emerging role of ectopic lipid in obesity-related renal disease. Lancet Diabetes Endocrinol . 2014;2(5):417-426. doi:10.1016/S2213-8587(14)70065-8 Gai Z, Wang T, Visentin M, Kullak-Ublick GA, Fu X, Wang Z. Lipid accumulation and chronic kidney disease. Nutrients . 2019;11(4):722. doi:10.3390/nu11040722 He L, Hao L, Fu X, Huang M, Li R. Severe hypertriglyceridemia and hypercholesterolemia accelerating renal injury: a novel model of type 1 diabetic hamsters induced by short-term high-fat / high-cholesterol diet and low-dose streptozotocin. BMC Nephrol . 2015;16:51. doi:10.1186/s12882-015-0041-5 Ma Y, Chen Y, Xu H, Du N. The influence of angiopoietin-like protein 3 on macrophages polarization and its effect on the podocyte EMT in diabetic nephropathy. Front Immunol . 2023;14:1228399. doi:10.3389/fimmu.2023.1228399 Cao Y, Lin JH, Hammes HP, Zhang C. Cellular phenotypic transitions in diabetic nephropathy: an update. Front Pharmacol . 2022;13:1038073. doi:10.3389/fphar.2022.1038073 Ying Q, Wu G. Molecular mechanisms involved in podocyte EMT and concomitant diabetic kidney diseases: an update. Ren Fail . 2017;39(1):474-483. doi:10.1080/0886022X.2017.1313164 Ma Y, Liu J, Liu H, Han X, Sun L, Xu H. Podocyte protection by Angptl3 knockout via inhibiting ROS/GRP78 pathway in LPS-induced acute kidney injury. Int Immunopharmacol . 2022;105:108549. doi:10.1016/j.intimp.2022.108549 Ji B, Liu J, Ma Y, et al. Minnelide combined with Angptl3 knockout completely protects mice with adriamycin nephropathy via suppression of TGF-β1-Smad2 and p53 pathways. Int Immunopharmacol . 2023;115:109656. doi:10.1016/j.intimp.2022.109656 Ji B, Liu J, Yin Y, Xu H, Shen Q, Yu J. Minnelide combined with anti-ANGPTL3-FLD monoclonal antibody completely protects mice with adriamycin nephropathy by promoting autophagy and inhibiting apoptosis. Cell Death Dis . 2023;14(9):601. doi:10.1038/s41419-023-06124-0 Tables Tables 1 to 3 are available in the Supplementary Files section. Supplementary Files AdditionalFile1.docx AdditionalFile2.docx AdditionalFile3.docx AdditionalFile4.docx AdditionalFile5.docx AdditionalFile6.docx AdditionalFile7.docx AdditionalFile8.docx AdditionalFile9.docx AdditionalFile10.docx AdditionalFile11.docx AdditionalFile12.docx AdditionalFile13.docx Personalcover.docx Table1.docx Table2.docx Table3.docx Cite Share Download PDF Status: Under Review Version 1 posted Reviewers agreed at journal 14 Jan, 2026 Reviewers invited by journal 14 Jan, 2026 Editor assigned by journal 02 Jan, 2026 First submitted to journal 30 Dec, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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glomerular diseases (n=25). Scale bars: 20 μm (black); 20 μm (white).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1B:\u003c/strong\u003e Quantitative analysis of Synaptopodin fluorescence intensity after glomerular immunofluorescence staining.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1C: \u003c/strong\u003eQuantitative analysis of P57-positive podocytes after glomerular immunofluorescence staining.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1D:\u003c/strong\u003e Quantitative analysis of the mean optical density of ANGPTL3 after glomerular IHC staining.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1E:\u003c/strong\u003e Analysis of the correlation between glomerular ANGPTL3 expression and P57-positive podocyte count in all the subjects (n=30).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1F:\u003c/strong\u003e Analysis of the correlation between glomerular ANGPTL3 expression and Synaptopodin fluorescence intensity in all the subjects (n=30).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1G:\u003c/strong\u003e Analysis of the correlation between glomerular ANGPTL3 expression and urinary ANGPTL3 levels in glomerular diseases (n=25).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1H:\u003c/strong\u003e Analysis of the correlation between glomerular ANGPTL3 expression and serum ANGPTL3 levels in glomerular diseases (n=25).\u003c/p\u003e\n\u003cp\u003eData are expressed as medians (25th–75th percentiles, interquartile ranges). Mann–Whitney U test, \u003cem\u003eP\u003c/em\u003e \u0026lt; 0.05. Correlation analyses were conducted using the Spearman correlation coefficient\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8459364/v1/704bb636c479e22674937f34.png"},{"id":100796107,"identity":"c4d3981d-9eab-4d70-a2d8-7bc1bcf09e3d","added_by":"auto","created_at":"2026-01-21 13:40:25","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":87740,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eFlow chart of study participant enrollment\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eELISA, Enzyme-Linked Immunosorbent Assay.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-8459364/v1/c215aeac5fd1714d0b9833cf.png"},{"id":100611545,"identity":"3f6a1ed9-7b78-4f8b-9055-2b610304ed8d","added_by":"auto","created_at":"2026-01-19 16:41:23","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":73567,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eComparisons of serum and urine ANGPTL3 levels between glomerular diseasepatients and healthy controls\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3A:\u003c/strong\u003e Serum ANGPTL3 levels in the test set (healthy controls, n=103; glomerular disease patients, n=243).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3B: \u003c/strong\u003eUrinary ANGPTL3/Cre in the test set (healthy controls, n=103; glomerular disease patients, n=243).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3C:\u003c/strong\u003e Serum ANGPTL3 levels in the validation set (healthy controls, n=42; glomerular disease patients, n=108).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3D: \u003c/strong\u003eUrinary ANGPTL3/Cre in the validation set (healthy controls, n=42; glomerular disease patients, n=108).\u003c/p\u003e\n\u003cp\u003eData are expressed as medians (25th–75th percentiles, interquartile ranges). Mann–Whitney U test, \u003cem\u003eP\u003c/em\u003e \u0026lt; 0.05.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-8459364/v1/29c9329365ce66d8f8f5147b.png"},{"id":100611542,"identity":"97d6435c-0814-4c6d-ac05-bc72fc29d259","added_by":"auto","created_at":"2026-01-19 16:41:20","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":271677,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eClinical diagnostic performance of urinary ANGPTL3/Cre for podocyte injury\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e4A-4B:\u003c/strong\u003e Performance in the overall cohort of children with glomerular diseases. ROC curves for the diagnostic accuracy of urinary ANGPTL3/Cre, serum ANGPTL3, and standard clinical biomarkers alone or in combination. 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n=106; Others, n=43).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e5B:\u003c/strong\u003e Corresponding AUCs in the validation set (HSPN, n=19; IgA N, n=16; NS, n=37; Others, n=36).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e5C: \u003c/strong\u003eAUCs for urinary ANGPTL3/Cre by disease remission status in the test set (CR, n=43; PR, n=40).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e5D:\u003c/strong\u003e Corresponding AUCs according to remission status in the validation set (CR, n=12; PR, n=23).\u003c/p\u003e\n\u003cp\u003eCR: complete remission; PR: partial remission\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-8459364/v1/bc34eda2d19189e594e736f8.png"},{"id":102750174,"identity":"f1349a1c-8b2f-4185-9b29-e477688dae95","added_by":"auto","created_at":"2026-02-16 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16:42:24","extension":"docx","order_by":14,"title":"","display":"","copyAsset":false,"role":"supplement","size":13849,"visible":true,"origin":"","legend":"","description":"","filename":"Personalcover.docx","url":"https://assets-eu.researchsquare.com/files/rs-8459364/v1/e72afa667c5b32abe08177e1.docx"},{"id":100611570,"identity":"8470aa76-d505-4855-ab43-e3fc910eed2b","added_by":"auto","created_at":"2026-01-19 16:41:44","extension":"docx","order_by":15,"title":"","display":"","copyAsset":false,"role":"supplement","size":16532,"visible":true,"origin":"","legend":"","description":"","filename":"Table1.docx","url":"https://assets-eu.researchsquare.com/files/rs-8459364/v1/106055a2c2d1f6e56300df31.docx"},{"id":100611565,"identity":"0f758cf4-6d2c-4478-9fc8-f48455e8e21a","added_by":"auto","created_at":"2026-01-19 16:41:36","extension":"docx","order_by":16,"title":"","display":"","copyAsset":false,"role":"supplement","size":16507,"visible":true,"origin":"","legend":"","description":"","filename":"Table2.docx","url":"https://assets-eu.researchsquare.com/files/rs-8459364/v1/85106b6dc0fe7afaf380482e.docx"},{"id":100611527,"identity":"0f4d4338-df09-45ac-8250-7a6c713683a0","added_by":"auto","created_at":"2026-01-19 16:41:04","extension":"docx","order_by":17,"title":"","display":"","copyAsset":false,"role":"supplement","size":18601,"visible":true,"origin":"","legend":"","description":"","filename":"Table3.docx","url":"https://assets-eu.researchsquare.com/files/rs-8459364/v1/00cdb5e0040859c05ea29fa7.docx"}],"financialInterests":"","formattedTitle":"Urinary ANGPTL3: A Novel Noninvasive Biomarker for Podocyte Injury in Pediatric Glomerular Diseases","fulltext":[{"header":"Key points","content":"\u003cul start=\"50\"\u003e\n \u003cli\u003eUrinary ANGPTL3 is a robust, noninvasive indicator that is directly correlated with podocyte injury severity\u003c/li\u003e\n \u003cli\u003eUrinary ANGPTL3 demonstrates superior diagnostic accuracy and significantly improves risk stratification over conventional biomarkers.\u003c/li\u003e\n \u003cli\u003eUrinary ANGPTL3 demonstrates particular promise for detecting subclinical podocyte injury in patients with normalized proteinuria, addressing a critical unsatisfied clinical need.\u003c/li\u003e\n\u003c/ul\u003e"},{"header":"Introduction","content":"\u003cp\u003eGlomerular diseases are major causes of chronic kidney disease (CKD) and are leading contributors to end-stage kidney disease (ESKD) worldwide\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. Renal biopsy registry data indicate that primary glomerular diseases account for approximately 71% of all glomerular disease cases, imposing a heavy burden on healthcare in China\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. The core pathological mechanism underlying these conditions, including primary diseases such as acute and chronic glomerulonephritis, primary nephrotic syndrome (PNS), IgA Nephropathy (IgA N); secondary diseases like lupus nephritis (LN), Henoch-Sch\u0026ouml;nlein purpura nephritis (HSPN), and diabetic nephropathy (DN); and genetic diseases such as Alport syndrome, involves podocyte injury\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e. As terminally differentiated, nonrenewable components of the glomerular filtration barrier, podocytes are critical for preserving filtration integrity. Podocyte injury or loss triggers glomerular basement membrane (GBM) denudation and increased proteinuria, progressing to segmental or global glomerulosclerosis and ultimately leading to nephron loss and renal fibrosis. Thus, basic and clinical research targeting podocyte injury is indispensable for the prevention and management of CKD.\u003c/p\u003e \u003cp\u003eCurrent diagnostic approaches for podocyte injury in glomerular diseases mainly rely on clinical biomarkers reflecting renal dysfunction and structural compromise, including measurements of blood urea nitrogen (UREA) and serum creatinine (CREA) levels, as well as qualitative and quantitative assessments of proteinuria\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e. While these methodologies are characterized by low cost and noninvasive nature, a definitive diagnosis of suspected podocyte injury still requires renal biopsy. Recently, novel biomarkers for kidney diseases have also shown great clinical application potential. For instance, nephrin, podocin, synaptopodin, podocalyxin, CD2AP, ACTN4 (which encodes actinin 4), PTPRO (which encodes GLEPP-1), and WT1 mRNA have been isolated from the urine of patients with different glomerular diseases\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e. Despite these advances, the lack of a reliable noninvasive biomarker for podocyte injury continues to hinder timely therapeutic intervention and dynamic monitoring of disease progression.\u003c/p\u003e \u003cp\u003eANGPTL3 predominantly originates from hepatocytes, with minimal expression detectable in renal tissue\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e. Initially characterized for its established roles in lipid metabolism and angiogenesis\u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e, ANGPTL3 functions through the inhibition of lipoprotein lipase (LPL) and endothelial lipase (EL), consequently leading to increases in plasma triglyceride (TG) and very-low-density lipoprotein (VLDL) levels\u003csup\u003e\u003cspan additionalcitationids=\"CR9\" citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e. Accumulating evidence indicates that ANGPTL3 is also directly involved in podocyte pathophysiology. Our prior work demonstrated that elevated ANGPTL3 disrupts podocyte cytoskeletal integrity through specific signaling pathways, leading to foot process effacement and proteinuria\u003csup\u003e\u003cspan additionalcitationids=\"CR12 CR13 CR14 CR15\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u003c/sup\u003e. Experimental studies have further shown that inhibiting ANGPTL3 expression attenuates podocyte injury and apoptosis\u003csup\u003e\u003cspan additionalcitationids=\"CR18 CR19\" citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e\u003c/sup\u003e. Additionally, ANGPTL3 may indirectly potentiate renal injury through the induction of hyperlipidemia and inflammatory cascades\u003csup\u003e\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e. Notably, both the genetic ablation of ANGPTL3 and therapeutic targeting of its FLD domain ameliorate podocyte injury in preclinical models, supporting the potential of ANGPTL3 as a therapeutic target\u003csup\u003e\u003cspan additionalcitationids=\"CR23\" citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u003c/sup\u003e. Clinically, serum and urinary ANGPTL3 levels are correlated with disease severity in nephrotic syndrome and diabetic kidney disease, underscoring the translational relevance of ANGPTL3\u003csup\u003e11,25\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eDespite these insights, whether urinary ANGPTL3/Cre can serve as a broadly applicable, noninvasive biomarker for podocyte injury across the spectrum of pediatric glomerular diseases remains unclear; moreover, its utility in patients without significant proteinuria, a clinically challenging subgroup, has not been systematically evaluated.\u003c/p\u003e \u003cp\u003eOn the base of this rationale, we hypothesize that urinary ANGPTL3/Cre reflects podocyte injury independent of proteinuria status and demonstrates superior diagnostic performance in pediatric glomerular diseases. The aim of this study was to validate the correlation of urinary ANGPTL3/Cre with histological injury, evaluate the diagnostic accuracy and independent predictive value of urinary ANGPTL3/Cre in a large clinical cohort, and establish the particular usefulness of urinary ANGPTL3/Cre in detecting subclinical podocyte damage in patients with normal urinary protein excretion.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eStudy Design\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn this two‑phase study, pediatric participants aged 0–18 years were enrolled from the Children’s Hospital of Fudan University between July 2023 and July 2025.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePhase 1 (Pathological Cohort):\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis cohort included 25 children with glomerular diseases who underwent renal biopsy (kidney tissue collected during biopsy) and 5 children with renal tumors (adjacent normal kidney tissue obtained during surgical resection served as pathological controls).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePhase 2 (Clinical Cohort):\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA total of 351 children with glomerular diseases and 145 healthy children (normal controls) were enrolled and allocated into a testing set and a validation set at a ratio of 7:3 at the time of enrollment. Participants enrolled from July 2023 to December 2024 were assigned to the test set, while those enrolled from January 2025 to July 2025 composed the validation set.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eInclusion Criteria\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll participants in each study phase met the following corresponding criteria:\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePatients with glomerular diseases:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe diagnosis was based on international consensus criteria. The spectrum of diseases included but was not limited to PNS, IgAN, HSPN, and LN. PNS was defined clinically, whereas all other subtypes required pathological confirmation via renal biopsy. Participants could present with or without proteinuria. Specimens were collected during either the acute or remission phase. Prior treatment with steroids or immunosuppressants, as well as no prior treatment, was allowed.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eControl\u003c/strong\u003e \u003cstrong\u003eParticipants:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePathological Controls: Histologically normal kidney tissue was obtained from pediatric patients who underwent nephrectomy for renal tumors, with confirmed absence of glomerulopathy.\u003c/p\u003e\n\u003cp\u003eHealthy Controls: Control children had no history or laboratory evidence of hepatic/renal dysfunction, proteinuria, or other systemic illnesses.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eExclusion Criteria\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eParticipants in any phase were excluded if they met any of the following criteria:\u003c/p\u003e\n\u003cp\u003eSevere cardiac, hepatic, or renal insufficiency; concurrent severe infection at enrollment (including but not limited to urinary or respiratory tract infections); history of kidney transplantation or long-term dialysis; comorbidities such as tumors, metabolic syndrome, obesity, familial hypercholesterolemia, fatty liver disease, or hypothyroidism; severe immune dysfunction; and congenital malformations or functional disorders (including systemic sclerosis, dermatomyositis, and congenital anomalies of the kidney and urinary tract [CAKUT]).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eProcedure\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll participants underwent blood tests in the morning after an overnight fast.\u0026nbsp;Venous blood was obtained from the arm and collected in serum separator tubes.\u0026nbsp;The samples were maintained at room temperature for 30 minutes and subsequently centrifuged at 2,000×g for 10 minutes at 4 °C to isolate serum. Mid-stream urine samples were collected in the morning using sterile containers, and centrifuged at 2,000 × g for 10 min at 4 °C.\u0026nbsp;The resulting supernatants from both serum and urine were aliquoted into 1.5 ml tubes.\u0026nbsp;All the samples were\u0026nbsp;stored at -80 °C, and multiple thaw/freeze cycles were avoided.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eImmunohistochemical staining for ANGPTL3\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eRenal tissue paraffin sections (4 μm) were deparaffinized, subjected to antigen retrieval with EDTA (pH 9.0) at high temperature and pressure, and then treated with 3% H₂O₂ to block endogenous peroxidase activity. After blocking with 10% goat serum, the sections were incubated overnight at 4 °C with a primary antibody against ANGPTL3 (Thermo Fisher, MA5-35681, diluted 1:100). The sections were subsequently incubated at 37 °C for 45 min with a horseradish peroxidase-conjugated goat anti-rabbit secondary antibody (Abcam, ab205718, diluted 1:2000). Staining was visualized using DAB, and nuclei were counterstained with hematoxylin. Images were captured using an Olympus CX31 microscope, and the mean optical density of ANGPTL3 was analyzed with Image-Pro Plus 6.0 software.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eImmunofluorescence staining (dual-labeling of renal tissue)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFollowing deparaffinization, antigen retrieval, and blocking, renal paraffin sections were sequentially incubated with an anti-P57Kip2 antibody (1:200), an HRP-conjugated goat anti-rabbit secondary antibody (1:4000), and CY5-tyramide working solution. After citrate-based antigen retrieval, the sections were then incubated with a primary antibody against Synaptopodin (1:100) and an Alexa Fluor\u003csup\u003e®\u003c/sup\u003e 488-conjugated secondary antibody (1:400). Nuclei were counterstained with DAPI. Images were acquired using an Olympus BX53 fluorescence microscope coupled with a 3D HISTECH Pannoramic MIDI system. The mean fluorescence intensity of Synaptopodin and the number of P57-positive cells were quantified using Image-Pro Plus 6.0 software.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLaboratory Measurements\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eUrinary and serum ANGPTL3 levels were quantified using enzyme-Linked Immunosorbent Assay (ELISA) kits (serum ANGPTL3: ab254510, Abcam, Cambridge, UK; urinary ANGPTL3: SEKH0533, Solarbio, Beijing, China) in accordance with the manufacturers' instructions. All measurements were performed by personnel who were blinded to the patient data. The intra-assay and inter-assay coefficients of variation were both \u0026lt; 10%.\u0026nbsp;Urinary creatinine levels were measured using a commercial assay kit\u0026nbsp;(C0121, Njjcbio, Nanjing, China). Urinary ANGPTL3 concentrations were normalized to urinary creatinine levels and are expressed as\u0026nbsp;ng/g creatinine. Other laboratory indicators, including 24-h urine total protein (24-h UTP),\u0026nbsp;urinary protein quantitation (UPRO), urinary protein/creatinine ratio (UPCR), urinary red blood cells (URBC), serum albumin (ALB), UREA, CREA, total cholesterol (TC), TG, high-density lipoprotein (HDL), and VLDL, were measured using an autoanalyzer in the Department of Clinical Laboratory, Children's Hospital of Fudan University.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDefinitions\u003c/strong\u003e \u003csup\u003e26–31\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePodocyte injury: This condition encompasses a pathological continuum ranging from early, potentially reversible changes such as foot process effacement (FPE) and cytoskeletal rearrangement, to severe events including detachment from the GBM and apoptosis, ultimately culminating in irreversible podocyte depletion. In this study, podocyte injury was defined by the histological presence of FPE (confirmed by renal biopsy in all enrolled glomerular diseases except for PNS, which was clinically diagnosed).\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eNephrotic range proteinuria:\u003c/strong\u003e UPCR ≥ 200 mg/mmol (2 mg/mg) in the first morning void or 24-h UTP ≥ 1000 mg/m\u003csup\u003e2\u003c/sup\u003e/d corresponding to 3+ or 4+ by urine dipstick\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eNon-Nephrotic Range Proteinuria:\u003c/strong\u003e Protein reagent strip result ≥ 1+, with 0.2 \u0026lt; UPCR\u0026lt; 2 mg/mg or 24-h UTP \u0026lt; 1000 mg/m\u003csup\u003e2\u003c/sup\u003e/d.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eNormal protein excretion:\u003c/strong\u003e Protein reagent strip result from negative to trace, with UPCR ≤ 0.2 mg/mg (all the subjects in the normal excretion group in this study were children posttreatment).\u003c/p\u003e\n\u003cp\u003eIn this study, patients with normal protein excretion were further categorized into two groups:\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComplete remission (CR):\u003c/strong\u003e UPCR (based on first morning void or 24 h urine sample) ≤ 20 mg/mmol (0.2 mg/mg) or \u0026lt; 100 mg/m²/d, respectively, or negative or trace dipstick on three or more consecutive days. In addition to these features, complete remission included the resolution of hematuria, defined as \u0026lt; 5 RBCs/HPF. (In this study, all patients with NS achieved complete remission within 1 month, and the time to complete remission for patients with other disease types did not exceed 6 months.)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePartial remission (PR):\u0026nbsp;\u003c/strong\u003eUPCR (based on the first morning void or 24 h urine sample) ≤ 20 mg/mmol (0.2 mg/mg) or \u0026lt; 100 mg/m²/d, respectively, or negative or trace dipstick on three or more consecutive days, with the presence of RBCs ≥ 5/HPF, and/or dysmorphic RBCs (acanthocytes), and/or RBC casts in a fresh spot urine sample.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eClinical data collection\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eClinical data, such as sex, age, body mass index (BMI), clinical symptoms, therapeutic regimen, and urinary and blood biological parameters were collected during hospitalization.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical analyses\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStatistical analyses were performed using GraphPad Prism 9.0 (GraphPad Software Inc., La Jolla, CA, USA), SPSS 26.0 (IBM, Armonk, NY, USA), and R version 4.1.2 (The R Foundation for Statistical Computing, Vienna, Austria). The aim of this study was to evaluate the clinical utility of urinary ANGPTL3/Cre as a biomarker for podocyte injury in pediatric glomerular diseases and to determine the potential of urinary ANGPTL3/Cre as an independent risk factor.\u0026nbsp;An additional aim of this study was to construct and validate predictive models that combine urinary ANGPTL3/Cre with clinical variables, and to assess the improvement of such models, compared with traditional clinical biomarkers or single ANGPTL3 indicators, in terms of diagnostic efficacy and risk reclassification.\u003cstrong\u003eData normality was assessed\u003c/strong\u003e using the Shapiro–Wilk test.\u0026nbsp;Normally distributed quantitative variables \u003cstrong\u003eare summarized\u0026nbsp;\u003c/strong\u003eas the mean ± standard deviation (SD),\u0026nbsp;wh\u003cstrong\u003eereas\u0026nbsp;\u003c/strong\u003enonnormally distributed data \u003cstrong\u003eare reported as\u003c/strong\u003e the median with interquartile range\u0026nbsp;(IQR). Student’s t-test was used to analyze the differential expression between two groups with normally distributed data, whereas the Mann‒Whitney U test was used to compare nonnormally distributed data between two groups.Multiple group comparisons \u003cstrong\u003ewere performed\u003c/strong\u003eusing\u0026nbsp;one-way analysis of variance (ANOVA)\u0026nbsp;for normally distributed variables and the Kruskal–Wallis test for nonnormally distributedvariables.\u0026nbsp;The relationship between urinary ANGPTL3/Cre and podocyte injury was evaluated using Spearman correlation analysis.\u0026nbsp;Univariate logistic regression analysis, multivariate logistic regression analysis, and LASSO regression analysis were employed to evaluate risk factors associated with glomerular diseases.\u0026nbsp;To evaluate predictive efficacy, the AUC was used to compare the discriminative performance of different risk prediction models (models with clinical variables only, models with biomarkers only, and combined models of biomarkers and clinical variables), with the DeLong test applied to assess differences between AUCs. The optimal cutoff values were identified via the Youden index in the test set and then applied to the validation set.\u0026nbsp;Against the model containing clinical variables alone as the reference, we used the net reclassification improvement (NRI) and integrated discrimination improvement (IDI) to evaluate the improvement in risk reclassification achieved by models that additionally incorporated ANGPTL3. Calibration curves were plotted to assess the agreement between the predicted probabilities and observed event rates.\u0026nbsp;All the statistical tests were two-tailed, with a significance level set at \u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.05.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003e\u003cstrong\u003eUrinary ANGPTL3/Cre is associated with podocyte injury in glomerular diseases\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eImmunofluorescence analysis revealed fewer P57-positive podocytes (a podocyte marker) and lower synaptopodin fluorescence intensity (a marker of podocyte injury) in the glomerular disease group than in the control group. Immunohistochemistry revealed elevated glomerular ANGPTL3 expression in the disease group (\u003cstrong\u003eFigure 1A\u003c/strong\u003e). Quantitative analyses confirmed that the synaptopodin fluorescence intensity and P57- positive podocyte count were significantly lower whereas the mean glomerular ANGPTL3 optical density was significantly greater in the glomerular disease group (all \u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001;\u0026nbsp;\u003cstrong\u003eFigure 1B\u003c/strong\u003e–\u003cstrong\u003e1D\u003c/strong\u003e). Correlation analyses revealed that the mean glomerular ANGPTL3 optical density was negatively correlated with the P57-positive podocyte count (\u003cem\u003er\u003c/em\u003e = –0.55,\u003cem\u003e\u0026nbsp;P\u003c/em\u003e = 0.002) and the synaptopodin fluorescence intensity (\u003cem\u003er\u003c/em\u003e = –0.37, \u003cem\u003eP\u003c/em\u003e = 0.04); in contrast, it showed a strong positive correlation with urinary ANGPTL3/Cre (\u003cem\u003er\u003c/em\u003e = 0.64, \u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001) and no correlation with serum ANGPTL3 levers (\u003cem\u003er\u003c/em\u003e = 0.00, \u003cem\u003eP\u003c/em\u003e = 0.99) (\u003cstrong\u003eFigure 1E\u003c/strong\u003e–\u003cstrong\u003e1H\u003c/strong\u003e). The relevant baseline data are presented in \u003cstrong\u003eAdditional File 1\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCohort Description\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eA total of 646 pediatric patients with kidney diseases and healthy controls were initially recruited from the Children's Hospital of Fudan University for potential inclusion in the test set. After screening, 346 individuals were included in the final analysis. Similarly, for the validation set, 310 participants were initially recruited, of whom 150 were ultimately analyzed (\u003cstrong\u003eFigure 2\u003c/strong\u003e). The proportions of healthy controls (29.8% vs. 28%) and patients with glomerular diseases (70.2% vs. 72.0%) were similar between the test and validation sets. The distribution of major disease subtypes was also largely consistent between the two sets, including IgA N (15.3% vs. 10.7%), NS (30.6% vs. 24.7%), HSPN (11.8% vs. 12.7%), and other diseases (12.4% vs. 24%). This consistent distribution pattern was similarly observed within the normal protein excretion subgroup (\u003cstrong\u003eAdditional File 2\u003c/strong\u003e). The baseline characteristics of all the enrolled participants are detailed in \u003cstrong\u003eAdditional File 3\u003c/strong\u003e. Data on 24‑h UTP were unavailable for healthy controls, as this test is not routinely performed in healthy pediatric screening. Patients with glomerular diseases were further stratified into three subgroups on the basis of proteinuria level: nephrotic range proteinuria, non‑nephrotic range proteinuria, and normal protein excretion. Their corresponding baseline characteristics are summarized separately for the test and validation sets in \u003cstrong\u003eAdditional File 4\u003c/strong\u003e. Overall, the baseline clinical and laboratory profiles were highly concordant between the validation set and the test set. Moreover, intergroup differences in UPRO, URBC, ALB, TC, TG, HDL, and VLDL reflected the characteristic clinical profile of glomerular diseases.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eANGPTL3 Levels as Predictors of Podocyte Injury in Glomerular Disease\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn the test set, the serum ANGPTL3 concentration was 40.27 (24.51, 55.62) ng/ml in the control group and 63.99 (42.99, 103.75) ng/ml in the glomerular disease group (\u003cstrong\u003eFigure 3A; Table 1\u003c/strong\u003e; \u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001). Urinary ANGPTL3/Cre was also significantly greater in the glomerular disease group [0.77 (0.27, 1.78) ng/g] than in the control group [0.09 (0.02, 0.28) ng/g] (\u003cstrong\u003eFigure 3B; Table 1\u003c/strong\u003e; \u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001). These findings were robustly validated in the independent validation set, where both serum ANGPTL3 and urinary ANGPTL3/Cre remained significantly elevated in the glomerular disease group (\u003cstrong\u003eFigure 3C, 3D\u003c/strong\u003e; both \u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.001). The consistent elevation of ANGPTL3 in serum and urine suggests its potential pathogenic role in podocyte injury among children with glomerular diseases. Subgroup analyses stratified by proteinuria status demonstrated that urinary ANGPTL3/Cre was persistently elevated in patients with podocyte injury compared with healthy controls across all proteinuria subgroups in the test set. Moreover, serum ANGPTL3 levels tended to decrease with increasing proteinuria severity. However, in the validation set, there was no statistically significant difference in serum ANGPTL3 levels between the normal protein excretion subgroup and the healthy control subgroup (\u003cstrong\u003eAdditional File 5A, 5C\u003c/strong\u003e). Across both sets, urinary ANGPTL3/Cre levels remained elevated in children with podocyte injury relative to those in healthy controls, regardless of proteinuria status. Nonetheless, no significant differences in urinary ANGPTL3/Cre were detected among subgroups stratified by proteinuria excretion level (\u003cstrong\u003eAdditional File 5B, 5D\u003c/strong\u003e).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eUrinary ANGPTL3/Cre as an Independent Risk Factor for Podocyte Injury in Glomerular Diseases\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo identify independent risk factors for podocyte injury in pediatric glomerular diseases, we implemented a sequential analytical strategy. Initial univariate analysis of the candidate variables revealed potential predictors of podocyte injury (\u003cem\u003eP\u003c/em\u003e \u0026lt; 0.1). Among these factors, urinary ANGPTL3/Cre was most strongly associated with podocyte injury severity (OR=13.30, 95% CI: 5.85–30.25, \u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001) (\u003cstrong\u003eAdditional File 6\u003c/strong\u003e). These predictors were subsequently analyzed using LASSO regression, which retained key variables for the final model (\u003cstrong\u003eAdditional File 7\u003c/strong\u003e). Multivariable logistic regression adjusted for confounders revealed that BMI, URBC, TG, and urinary ANGPTL3/Cre were independent risk factors, whereas the serum ALB concentration served as a protective factor. Notably, urinary ANGPTL3/Cre exhibited the greatest effect size, with each 1-unit increase corresponding to a 7.66-fold increase in the risk of significant podocyte injury (OR=7.66, 95% CI: 2.27–25.84, \u003cem\u003eP\u0026nbsp;\u003c/em\u003e= 0.001). Other significant factors included URBC (OR=1.06, \u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.001), TG (OR=2.78, \u003cem\u003eP\u0026nbsp;\u003c/em\u003e= 0.020), BMI (OR=1.17, \u003cem\u003eP\u0026nbsp;\u003c/em\u003e= 0.023), and ALB (OR= 0.55, \u003cem\u003eP\u0026nbsp;\u003c/em\u003e\u0026lt; 0.001) (\u003cstrong\u003eTable 2\u003c/strong\u003e).\u0026nbsp;These findings establish urinary ANGPTL3/Cre as a prominent and independent risk factor for podocyte injury in pediatric glomerular diseases.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePredictive Performance of Urinary ANGPTL3/Cre in the Early Diagnosis of\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003ePodocyte Injury in\u003c/strong\u003e\u003cstrong\u003eGlomerular Disease\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eUrinary ANGPTL3/Cre demonstrated excellent diagnostic performance for podocyte injury in glomerular diseases, with AUC values of 0.90 (95% CI: 0.85–0.93) in the test set and 0.90 (95% CI: 0.84–0.95) in the validation set (\u003cstrong\u003eFigure 4A\u003c/strong\u003e–\u003cstrong\u003e4B, Additional File 8\u003c/strong\u003e). This diagnostic capability remained robust in patients with normal protein excretion (AUC=0.87/0.84) (\u003cstrong\u003eFigure 4C\u003c/strong\u003e–\u003cstrong\u003e4D\u003c/strong\u003e). This robust diagnostic performance was consistent across all disease subtypes, with AUCs exceeding 0.80 in both sets for NS, IgA N, HSPN and other subtypes. Among patients with normal protein excretion, urinary ANGPTL3/Cre also exhibited strong diagnostic value across remission statuses, with AUCs of 0.92 in the test set and 0.87 in the validation set for PR and 0.84 in the test set and 0.77 in the validation set for CR (\u003cstrong\u003eFigure 5\u003c/strong\u003e).\u003c/p\u003e\n\u003cp\u003eUsing the optimal cutoff value of 0.29 derived from the test set, urinary ANGPTL3/Cre had a sensitivity of 0.71, a specificity of 0.91, positive predictive value (PPV) of 0.95, and negative predictive value (NPV) of 0.57 for detecting podocyte injury. This performance profile was preserved in the validation set and across disease subtypes, with consistent sensitivity and stable specificity, confirming its broad applicability across diverse clinical presentations of podocyte injury (\u003cstrong\u003eAdditional File 9, 10\u003c/strong\u003e). Furthermore, urinary ANGPTL3/Cre significantly outperformed both serum ANGPTL3 (AUC = 0.76) and traditional biomarkers including UPRO, URBC, ALB, UREA, and CREA (all \u003cem\u003eP\u003c/em\u003e \u0026lt; 0.05; DeLong test) (\u003cstrong\u003eAdditional File 11\u003c/strong\u003e). We subsequently constructed combined models by integrating urinary ANGPTL3/Cre and/or serum ANGPTL3 with three variable sets, including serum clinical variables (UREA + CREA + ALB), urinary clinical variables (URBC + UPRO), and predictor variables (URBC + ALB + TG + BMI, obtained through multivariate logistic regression screening). Compared with their corresponding base model, all the combined models showed improved diagnostic efficacy for podocyte injury, with distinct performance characteristics. The predictor variables combined model (urinary ANGPTL3/Cre + predictor variables) achieved favorable predictive performance with fewer variables (AUC = 0.93, 95% CI: 0.91–0.96). In contrast, the full-variable combined model (urinary ANGPTL3/Cre + serum ANGPTL3 + all clinical variables) showed optimal predictive performance (AUC = 0.95; 95% CI: 0.93–0.97). Notably, the urinary clinical variables combined model (urinary ANGPTL3/Cre + urinary clinical variables) demonstrated comparable predictive performance to that of the full-variable model, with an AUC of 0.95 (95% CI: 0.93–0.97) (\u003cstrong\u003eFigure 4A\u003c/strong\u003e–\u003cstrong\u003e4B)\u003c/strong\u003e.\u003c/p\u003e\n\u003cp\u003eThis predictive performance was retained in the subgroup of patients with normal protein excretion, where urinary ANGPTL3/Cre alone achieved AUCs of 0.87 (test set) and 0.84 (validation set) for podocyte injury. In this subgroup, the urinary clinical combined variables model (AUC = 0.89) demonstrated comparable performance to the full-variable combined model (AUC = 0.90) but required the fewest variables (\u003cstrong\u003eFigure 4A\u003c/strong\u003e–\u003cstrong\u003e4B)\u003c/strong\u003e. The calibration curves for the core models showed acceptable agreement between the predicted and observed probabilities in both sets (\u003cstrong\u003eAdditional File 12\u003c/strong\u003e).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEffect of Urinary ANGPTL3/Cre on Risk Reclassification for Podocyte Injury\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTo evaluate whether urinary ANGPTL3/Cre improves risk reclassification for podocyte injury, we analyzed the category-free NRI, NRI in progressors, NRI in non-progressors, and IDI in both the test and validation sets. The inclusion of urinary ANGPTL3/Cre generally improved risk reclassification in both sets, with urinary clinical variables combined model demonstrating the most notable performance. This model had the highest category-free NRI across the models, with values of 0.63 (95% CI: 0.48–0.78) in the test set and 0.58 (95% CI: 0.35–0.75) in the validation set. Moreover, it result in a significant positive improvement in NRI for progressors in the test set (0.07, 95% CI: 0.01–0.12), while maintaining a high NRI for non-progressors in both sets (0.57 and 0.56, respectively), highlighting its dual capacity to accurately identify individuals with podocyte injury and rule out healthy individuals (\u003cstrong\u003eTable 3\u003c/strong\u003e).\u003c/p\u003e\n\u003cp\u003eFurther analysis of patients with podocyte injury but normal protein excretion revealed even greater improvement with urinary ANGPTL3/Cre. Specifically, the category-free NRI of the urinary clinical variables combined model reached 0.94 (95% CI: 0.67–1.18), which was substantially greater than that observed in the overall population. This model also yielded an NRI for progressors of 0.29 (95% CI: 0.08–0.50), an NRI for non-progressors of 0.64 (95% CI: 0.49–0.78), and an IDI of 0.35 (95% CI: 0.28–0.43). In this subgroup,\u0026nbsp;the full-variable combined model\u0026nbsp;exhibited optimal performance, achieving the highest category-free NRI (1.08, 95% CI: 0.82–1.32), NRI for progressors (0.42, 95% CI: 0.20–0.61), NRI for non-progressors (0.67, 95% CI: 0.50–0.81), and IDI (0.35, 95% CI: 0.27–0.42) (\u003cstrong\u003eAdditional File 13\u003c/strong\u003e). Nevertheless, the urinary clinical variables combined model represents a pragmatically superior choice for clinical translation because of its noninvasive profile and fewer required variables.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study systematically investigated the association between ANGPTL3 and podocyte injury in glomerular diseases, establishing for the first time that urinary ANGPTL3/Cre is a valuable non‑invasive biomarker with significant clinical potential. Our findings demonstrate that urinary ANGPTL3/Cre reflects the extent of podocyte injury and exhibits not only excellent diagnostic performance but also particular utility in clinical settings where conventional biomarkers are inadequate.\u003c/p\u003e \u003cp\u003eThis study established a direct link between glomerular ANGPTL3 expression and podocyte injury at the tissue level and validated urinary ANGPTL3/Cre as a noninvasive biomarker for such damage. Significantly elevated ANGPTL3 expression was observed in the glomerular disease group, showing a negative correlation with podocyte number and the podocyte functional marker synaptopodin. These findings suggest that local glomerular upregulation of ANGPTL3 may directly contribute to the pathological process of podocyte injury. Previous investigations have shown that ANGPTL3 can disrupt podocyte cytoskeletal integrity via the integrin αvβ3-FAK-PI3K-Rac1 pathway, leading to foot process effacement and proteinuria\u003csup\u003e\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u003c/sup\u003e. Our work substantially expands the pathological significance of ANGPTL3 beyond that of PNS\u003csup\u003e\u003cspan additionalcitationids=\"CR12\" citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e and DN\u003csup\u003e32\u003c/sup\u003e, further supporting its role as a common regulatory factor in podocyte injury. The strong positive correlation between glomerular ANGPTL3 and urinary ANGPTL3/Cre, coupled with the absence of correlation with serum ANGPTL3, indicates that urinary ANGPTL3/Cre more closely reflects local glomerular secretion and directly reflects renal pathological alterations of ANGPTL3. In contrast, serum ANGPTL3 may be influenced by systemic metabolic factors. This characteristic provides a crucial rationale for the non-invasive clinical assessment of podocyte injury.\u003c/p\u003e \u003cp\u003eUrinary ANGPTL3/Cre demonstrated remarkable diagnostic efficacy for podocyte injury, with an AUC of 0.90, which significantly surpassed that of both serum ANGPTL3 and conventional biomarkers. This performance compares favorably with other reported urinary biomarkers, exceeding those for CD4\u0026thinsp;+\u0026thinsp;T cells in ANCA-associated vasculitis (AUC\u0026thinsp;=\u0026thinsp;0.88)\u003csup\u003e33\u003c/sup\u003e and podocyte mRNAs in diabetic nephropathy (AUC\u0026thinsp;=\u0026thinsp;0.72)\u003csup\u003e34\u003c/sup\u003e, matching that of urinary nephrin (AUC\u0026thinsp;=\u0026thinsp;0.90)\u003csup\u003e35\u003c/sup\u003e, and surpassing that of urinary CD80 (AUC\u0026thinsp;=\u0026thinsp;0.83)\u003csup\u003e35\u003c/sup\u003e. Notably, urinary ANGPTL3/Cre maintains consistent diagnostic efficacy in patients with normal urinary protein excretion, while urinary nephrin shows restricted diagnostic performance in hypertensive nephropathy (AUC\u0026thinsp;=\u0026thinsp;0.63)\u003csup\u003e37\u003c/sup\u003e. Although this subgroup included posttreatment patients, the observed increase in urinary ANGPTL3/Cre suggests that it may increase during early disease stages prior to the onset of proteinuria, offering a distinct advantage for the early detection of podocyte injury. Furthermore, its sustained increase during clinical remission likely reflects persistent subclinical podocyte injury or may indicate a biological predisposition to relapse. This ability to detect residual podocyte injury in the absence of proteinuria constitutes a unique advantage over conventional monitoring.\u003c/p\u003e \u003cp\u003eIn predictive modeling, a simple urinary model combining ANGPTL3/Cre, UPRO, and URBC achieved outstanding performance (AUC\u0026thinsp;=\u0026thinsp;0.95), comparable to that of a complex model incorporating all serum and clinical variables. This urinary model maintained robust performance in the challenging normal protein excretion subgroup (AUC\u0026thinsp;=\u0026thinsp;0.89) while delivering substantial net reclassification improvement (NRI\u0026thinsp;=\u0026thinsp;0.94) and integrated discrimination improvement (IDI\u0026thinsp;=\u0026thinsp;0.35). Although the full combination model showed marginally better metrics in this subgroup (AUC\u0026thinsp;=\u0026thinsp;0.91, NRI\u0026thinsp;=\u0026thinsp;1.08, IDI\u0026thinsp;=\u0026thinsp;0.35), the urinary model exhibited superior clinical applicability because of its minimal variable set and completely noninvasive profile. This capacity for accurate, noninvasive diagnosis not only optimizes the clinical workflow and reduces costs but also provides a practical strategy for the early detection of podocyte injury.\u003c/p\u003e \u003cp\u003eMultivariable logistic regression revealed that urinary ANGPTL3/Cre, URBC, ALB, TG, and BMI were independent factors associated with podocyte injury risk. These findings align with prior reports linking URBC, TG, and BMI to CKD progression\u003csup\u003e\u003cspan additionalcitationids=\"CR39\" citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e\u003c/sup\u003e, and ALB to protection\u003csup\u003e\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e\u003c/sup\u003e. Among these factors, urinary ANGPTL3/Cre had the strongest association. In contrast, serum ANGPTL3 was not identified as an independent risk factor, underscoring the superior relevance of the urinary biomarker.\u003c/p\u003e \u003cp\u003eANGPTL3 may contribute to podocyte injury through multiple pathways. The first constitutes a direct injury pathway operating through the integrin αvβ3-FAK-PI3K-Rac1 signaling axis that disrupts podocyte cytoskeletal architecture. The second represents a lipid metabolism-dependent pathway in which the ANGPTL3-mediated inhibition of LPL and EL activity triggers an increase in triglycerides. Gao et al. confirmed that ANGPTL3 contributes to both proteinuria and hyperlipidemia in PNS. Furthermore, animal experiments have revealed that the role of ANGPTL3 in hyperlipidemic-induced renal injury is mediated by ACTN4\u003csup\u003e42\u003c/sup\u003e, a key podocyte cytoskeletal protein whose dysregulation leads to foot process effacement\u003csup\u003e\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u003c/sup\u003e. These discoveries correspond with fundamental CKD understanding that identifies lipotoxicity as crucial for disease progression, while K/DOQI guidelines specifically designate dyslipidemia as a CKD progression marker\u003csup\u003e\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e\u003c/sup\u003e. Substantial research has demonstrates that hyperlipidemia can induce endoplasmic reticulum (ER) stress, inflammatory responses, and excessive reactive oxygen species (ROS) generation, which directly damage renal structures\u003csup\u003e\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e\u003c/sup\u003e while simultaneously promoting lipid accumulation and functional-structural modifications across various renal cell types including podocytes, mesangial cells, and tubular elements\u003csup\u003e\u003cspan additionalcitationids=\"CR47\" citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe mechanistic spectrum of ANGPTL3 action appears increasingly complex. Previous studies have proposed that the inhibition of podocyte epithelial-mesenchymal transition (EMT) constitutes a novel mechanism through which ANGPTL3 knockout alleviates podocyte injury\u003csup\u003e\u003cspan additionalcitationids=\"CR50\" citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e\u003c/sup\u003e. In AKI, ANGPTL3 knockdown diminishes podocyte apoptosis by modulating the ROS/GRP78 signaling pathway\u003csup\u003e\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e\u003c/sup\u003e. These mechanisms collectively form an intricate network through which ANGPTL3 mediates renal damage.\u003c/p\u003e \u003cp\u003eIn summary, in this study, urinary ANGPTL3/Cre was established as an effective biomarker for podocyte injury in clinical practice, the mechanistic understanding of ANGPTL3 as a critical node that links renal injury and metabolic dysregulation was advanced. Elevated urinary ANGPTL3/Cre indicates active podocyte injury and provides critical information beyond conventional biomarkers, especially in patients with low or normalized proteinuria.\u003c/p\u003e \u003cp\u003eNotably, our team has developed an anti‑ANGPTL3‑FLD monoclonal antibody that significantly reduced proteinuria, podocyte apoptosis, ROS production, and mitochondrial fragmentation in a nephropathy model\u003csup\u003e\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e,\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e,\u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e\u003c/sup\u003e. Furthermore, an anti‑ANGPTL3/IL‑22 bifunctional fusion protein improved both proteinuria and glucose metabolism in diabetic nephropathy while suppressing inflammation and fibrosis\u003csup\u003e\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u003c/sup\u003e. These findings provide a solid foundation for clinical translation of innovative biologics. To address the limitations of commercial assays encountered in this study, we are currently developing a high‑sensitivity detection kit based on this proprietary anti‑ANGPTL3‑FLD antibody.\u003c/p\u003e \u003cp\u003eThis study has several limitations. First, this was a single‑center, cross‑sectional investigation. Although the Children\u0026rsquo;s Hospital of Fudan University is a national pediatric medical center with patients from across the country, geographic selection bias may still exist. Second, urinary ANGPTL3/Cre was not longitudinally monitored during different disease states or treatment phases, and its potential for guiding relapse management or treatment adjustment remains unassessed. Third, associations with pathological severity across different glomerular disease subtypes were not addressed.\u003c/p\u003e \u003cp\u003eFuture research should proceed along three lines. First, multicenter, large‑sample cohort studies with external validation in collaboration with pediatric hospitals in other regions should be conducted. Second, prospective cohort studies tracking changes in ANGPTL3 levels in relation to glomerular disease outcomes will help clarify its prognostic utility. Third, subgroup analyses stratified by glomerular disease subtype and pathological severity are needed to explore how ANGPTL3 relates to disease‑specific pathological progression.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eIn summary, in this study, urinary ANGPTL3/Cre was identified as a noninvasive and independent risk factor closely associated with podocyte injury in pediatric glomerular diseases. It outperformed conventional biomarkers in terms of diagnostic efficacy and sensitively indicated subclinical podocyte injury even when proteinuria levels were normal. Moreover, this marker shows promise as a screening tool to guide targeted ANGPTL3 therapies, laying the groundwork for individualized treatment. As a noninvasive biomarker with both mechanistic relevance and translational potential, urinary ANGPTL3/Cre may reshape diagnostic and therapeutic strategies for glomerular diseases involving podocyte injury and ultimately improve clinical outcomes.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003e24-h UTP \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;24-h urine total protein\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eALB \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Albumin\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eANGPTL3 \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Angiopoietin-like protein 3\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eANGPTL3/Cre \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;ANGPTL3-to-creatinine ratio\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eANOVA \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;One-way analysis of variance\u003c/p\u003e\n\u003cp\u003eAUC \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Area under the curve\u003c/p\u003e\n\u003cp\u003eCAKUT \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Congenital anomalies of the kidney and urinary tract\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eCKD \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Chronic kidney disease\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eCREA \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Creatinine\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eDN \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Diabetic nephropathy\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eEL \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Endothelial lipase\u003c/p\u003e\n\u003cp\u003eELISA \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Enzyme-Linked Immunosorbent Assay\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eEMT \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Epithelial-mesenchymal transition\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eER \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Endoplasmic reticulum\u003c/p\u003e\n\u003cp\u003eESKD \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;End-stage kidney disease\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFPE \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Foot process effacement\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eGBM \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Glomerular basement membrane\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHDL \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;High-density lipoprotein\u003c/p\u003e\n\u003cp\u003eHSPN \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Henoch-Sch\u0026ouml;nlein purpura nephritis\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIDI \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Integrated discrimination improvement\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIgA N \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;IgA Nephropathy\u003c/p\u003e\n\u003cp\u003eIQR \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Interquartile range\u003c/p\u003e\n\u003cp\u003eLN \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Lupus nephritis\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eLPL \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Lipoprotein lipase\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eNRI \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Net reclassification improvement\u003c/p\u003e\n\u003cp\u003ePNS \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Primary nephrotic syndrome\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eROC \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Receiver operating characteristic\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eROS \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Reactive oxygen species\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSD \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Standard deviation\u003c/p\u003e\n\u003cp\u003eTC \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Total cholesterol\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTG \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Triglycerides\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eUPCR \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Urinary protein/creatinine ratio\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eUPRO \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Urinary protein quantitation\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eURBC \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Urinary red blood cells\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eUREA \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;\u0026nbsp;Urea nitrogen\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eVLDL \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp;Very-low-density lipoprotein\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData availability statement\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe de-identified datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was approved by the Research Ethics Committee of the Children’s Hospital of Fudan University (Approval No. (2021)-446) and conducted in accordance with the Declaration of Helsinki. Written informed consent was obtained from the legal guardians or next of kin of all participants. No personal identification information of participants was collected, and the shared datasets are de-identified to protect privacy.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eShanghai Municipal Health Commission Program (2025ZZ2008, 202240280);\u003c/p\u003e\n\u003cp\u003eShanghai Municipal Science and Technology Major Project (2023SHZDZX02C09); Shanghai Municipal Science and Technology \"Innovation Action Plan\" Basic Research Field Project (23JC1401200);\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor Contributions\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHX conceived the study, acquired funding, provided essential resources, and supervised the entire research process. HW, JL, and RD conducted the investigation, with HW and JL responsible for data curation. HW and XC designed the methodology and performed formal analysis. XW provided software support for data processing. QS and YZ contributed to resource provision and study supervision, and YZ also participated in funding acquisition. JLiu (Jialu Liu), XT, and XH participated in the study discussions and provided critical insights for result interpretation. HW\u003csup\u003e†\u003c/sup\u003e, JL\u003csup\u003e†\u003c/sup\u003e, and RD\u003csup\u003e†\u003c/sup\u003e drafted the original manuscript.\u0026nbsp;\u003csup\u003e†\u003c/sup\u003eThese authors contributed equally to this work and share the first authorship. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe acknowledge all investigators for their cooperation.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eChen CH, Wu HY, Wang CL, et al. Proteinuria as a therapeutic target in advanced chronic kidney disease: a retrospective multicenter cohort study. \u003cem\u003eSci Rep\u003c/em\u003e. 2016;6:26539. doi:10.1038/srep26539\u003c/li\u003e\n\u003cli\u003eUsui T, Kanda E, Iseki C, Iseki K, Kashihara N, Nangaku M. Observation period for changes in proteinuria and risk prediction of end-stage renal disease in general population. \u003cem\u003eNephrol Carlton Vic\u003c/em\u003e. 2018;23(9):821-829. doi:10.1111/nep.13093\u003c/li\u003e\n\u003cli\u003eChen H, Tang Z, Zeng C, et al. Pathological demography of native patients in a nephrology center in China. \u003cem\u003eChin Med J (Engl)\u003c/em\u003e. 2003;116(9):1377-1381.\u003c/li\u003e\n\u003cli\u003eSethi S, Fervenza FC. Standardized classification and reporting of glomerulonephritis. \u003cem\u003eNephrol Dial Transplant Off Publ Eur Dial Transpl Assoc - Eur Ren Assoc\u003c/em\u003e. 2019;34(2):193-199. doi:10.1093/ndt/gfy220\u003c/li\u003e\n\u003cli\u003eSekulic M, Pichler Sekulic S. A compendium of urinary biomarkers indicative of glomerular podocytopathy. \u003cem\u003ePathol Res Int\u003c/em\u003e. 2013;2013:782395. doi:10.1155/2013/782395\u003c/li\u003e\n\u003cli\u003eKim I, Kwak HJ, Ahn JE, et al. Molecular cloning and characterization of a novel angiopoietin family protein, angiopoietin-3. \u003cem\u003eFEBS Lett\u003c/em\u003e. 1999;443(3):353-356. doi:10.1016/s0014-5793(99)00008-3\u003c/li\u003e\n\u003cli\u003eSantulli G. Angiopoietin-like proteins: a comprehensive look. \u003cem\u003eFront Endocrinol\u003c/em\u003e. 2014;5:4. doi:10.3389/fendo.2014.00004\u003c/li\u003e\n\u003cli\u003eEssalmani R, Susan-Resiga D, Chamberland A, et al. Furin is the primary in vivo convertase of angiopoietin-like 3 and endothelial lipase in hepatocytes. \u003cem\u003eJ Biol Chem\u003c/em\u003e. 2013;288(37):26410-26418. doi:10.1074/jbc.M113.501304\u003c/li\u003e\n\u003cli\u003eLiu J, Afroza H, Rader DJ, Jin W. Angiopoietin-like protein 3 inhibits lipoprotein lipase activity through enhancing its cleavage by proprotein convertases. \u003cem\u003eJ Biol Chem\u003c/em\u003e. 2010;285(36):27561-27570. doi:10.1074/jbc.M110.144279\u003c/li\u003e\n\u003cli\u003eRobciuc MR, Maranghi M, Lahikainen A, et al. Angptl3 deficiency is associated with increased insulin sensitivity, lipoprotein lipase activity, and decreased serum free fatty acids. \u003cem\u003eArterioscler Thromb Vasc Biol\u003c/em\u003e. 2013;33(7):1706-1713. doi:10.1161/ATVBAHA.113.301397\u003c/li\u003e\n\u003cli\u003eWen F, Liu J, Dai R, et al. Angiopoietin-like protein 3: a novel potential biomarker for nephrotic syndrome in children. \u003cem\u003eFront Pediatr\u003c/em\u003e. 2023;11:1113484. doi:10.3389/fped.2023.1113484\u003c/li\u003e\n\u003cli\u003eLiu J, Xu H, Dai R, et al. Potential function of angiopoietin-like protein 3 in hyperlipidemia of nephrotic syndrome. \u003cem\u003eChin J Nephrol\u003c/em\u003e. 2015;31(9):669-673. doi:10.3760/cma.j.issn.1001-7097.2015.09.006\u003c/li\u003e\n\u003cli\u003eZhong F, Liu S, Li Y, et al. ANGPTL3 impacts proteinuria and hyperlipidemia in primary nephrotic syndrome. \u003cem\u003eLipids Health Dis\u003c/em\u003e. 2022;21(1):38. doi:10.1186/s12944-022-01632-y\u003c/li\u003e\n\u003cli\u003eLiu J, Gao X, Zhai Y, et al. A novel role of angiopoietin-like-3 associated with podocyte injury. \u003cem\u003ePediatr Res\u003c/em\u003e. 2015;77(6):732-739. doi:10.1038/pr.2015.38\u003c/li\u003e\n\u003cli\u003eGao X, Xu H, Liu H, Rao J, Li Y, Zha X. Angiopoietin-like protein 3 regulates the motility and permeability of podocytes by altering nephrin expression in vitro. \u003cem\u003eBiochem Biophys Res Commun\u003c/em\u003e. 2010;399(1):31-36. doi:10.1016/j.bbrc.2010.07.027\u003c/li\u003e\n\u003cli\u003eLin Y, Rao J, Zha XL, Xu H. Angiopoietin-like 3 induces podocyte F-actin rearrangement through integrin \u0026alpha;(V)\u0026beta;₃/FAK/PI3K pathway-mediated Rac1 activation. \u003cem\u003eBiomed Res Int\u003c/em\u003e. 2013;2013:135608. doi:10.1155/2013/135608\u003c/li\u003e\n\u003cli\u003eDai R, Liu H, Han X, et al. Angiopoietin-like-3 knockout protects against glomerulosclerosis in murine adriamycin-induced nephropathy by attenuating podocyte loss. \u003cem\u003eBMC Nephrol\u003c/em\u003e. 2019;20(1):185. doi:10.1186/s12882-019-1383-1\u003c/li\u003e\n\u003cli\u003eDai R, Lin Y, Liu H, et al. A vital role for Angptl3 in the PAN-induced podocyte loss by affecting detachment and apoptosis in vitro. \u003cem\u003eBMC Nephrol\u003c/em\u003e. 2015;16:38. doi:10.1186/s12882-015-0034-4\u003c/li\u003e\n\u003cli\u003eMa Y, Liu J, Liu H, Han X, Sun L, Xu H. Podocyte protection by Angptl3 knockout via inhibiting ROS/GRP78 pathway in LPS-induced acute kidney injury. \u003cem\u003eInt Immunopharmacol\u003c/em\u003e. 2022;105:108549. doi:10.1016/j.intimp.2022.108549\u003c/li\u003e\n\u003cli\u003eMa Y, Chen Y, Xu H, Du N. The influence of angiopoietin-like protein 3 on macrophages polarization and its effect on the podocyte EMT in diabetic nephropathy. \u003cem\u003eFront Immunol\u003c/em\u003e. 2023;14:1228399. doi:10.3389/fimmu.2023.1228399\u003c/li\u003e\n\u003cli\u003eTamehri Zadeh SS, Toth PP, Shapiro MD, Surma S, Banach M. ANGPTL3 vital role in different kidney diseases. Current knowledge and future perspectives. \u003cem\u003eBiomed Pharmacother Biomedecine Pharmacother\u003c/em\u003e. 2025;188:118189. doi:10.1016/j.biopha.2025.118189\u003c/li\u003e\n\u003cli\u003eLv Q, Han X, Ni J, et al. Anti-ANGPTL3-FLD monoclonal antibody treatment ameliorates podocyte lesions through attenuating mitochondrial damage. \u003cem\u003eCell Death Dis\u003c/em\u003e. 2022;13(10):867. doi:10.1038/s41419-022-05313-7\u003c/li\u003e\n\u003cli\u003eHan X, Dai R, Zhai Y, et al. Anti-proteinuria effect of antibody against ANGPTL3 coil-coiled domain on adriamycin-induced nephropathy in mice. \u003cem\u003eBiochem Biophys Res Commun\u003c/em\u003e. 2019;516(3):812-818. doi:10.1016/j.bbrc.2019.06.065\u003c/li\u003e\n\u003cli\u003eMa Q, Hu X, Liu F, et al. A novel fusion protein consisting of anti-ANGPTL3 antibody and interleukin-22 ameliorates diabetic nephropathy in mice. \u003cem\u003eFront Immunol\u003c/em\u003e. 2022;13:1011442. doi:10.3389/fimmu.2022.1011442\u003c/li\u003e\n\u003cli\u003eAzadi SM, Fadaei R, Omid-Shafaat R, Hosseini J, Moradi N. Elevated angiopoietin-like protein 3 serum levels in diabetic nephropathy patients and its association with renal function and lipid profile. \u003cem\u003eBMC Nephrol\u003c/em\u003e. 2023;24(1):172. doi:10.1186/s12882-023-03214-1\u003c/li\u003e\n\u003cli\u003eTrautmann A, Vivarelli M, Samuel S, et al. IPNA clinical practice recommendations for the diagnosis and management of children with steroid-resistant nephrotic syndrome. \u003cem\u003ePediatr Nephrol Berl Ger\u003c/em\u003e. 2020;35(8):1529-1561. doi:10.1007/s00467-020-04519-1\u003c/li\u003e\n\u003cli\u003eVivarelli M, Samuel S, Coppo R, et al. IPNA clinical practice recommendations for the diagnosis and management of children with IgA nephropathy and IgA vasculitis nephritis. \u003cem\u003ePediatr Nephrol\u003c/em\u003e. 2025;40(2):533-569. doi:10.1007/s00467-024-06502-6\u003c/li\u003e\n\u003cli\u003eKidney Disease: Improving Global Outcomes (KDIGO) Lupus Nephritis Work Group. KDIGO 2024 clinical practice guideline for the management of LUPUS NEPHRITIS. \u003cem\u003eKidney Int\u003c/em\u003e. 2024;105(1S):S1-S69. doi:10.1016/j.kint.2023.09.002\u003c/li\u003e\n\u003cli\u003eMaliakkal JG, Hicks MJ, Michael M, et al. Renal survival in children with glomerulonephritis with crescents: a pediatric nephrology research consortium cohort study. \u003cem\u003eJ Clin Med\u003c/em\u003e. 2020;9(8):2385. doi:10.3390/jcm9082385\u003c/li\u003e\n\u003cli\u003eXi L, Sun Y, Chen Y, Yang X, Su H, Ren X. Clinicopathological features and prognosis of IgA vasculitis nephritis with nephrotic-range proteinuria in children. \u003cem\u003ePediatr Nephrol\u003c/em\u003e. 2024;39(11):3241-3250. doi:10.1007/s00467-024-06441-2\u003c/li\u003e\n\u003cli\u003eFinn LS. Nephrotic syndrome throughout childhood: diagnosing podocytopathies from the womb to the dorm. \u003cem\u003ePediatr Dev Pathol\u003c/em\u003e. 2024;27(5):426-458. doi:10.1177/10935266241242669\u003c/li\u003e\n\u003cli\u003eAzadi SM, Fadaei R, Omid-Shafaat R, Hosseini J, Moradi N. Elevated angiopoietin-like protein 3 serum levels in diabetic nephropathy patients and its association with renal function and lipid profile. \u003cem\u003eBMC Nephrol\u003c/em\u003e. 2023;24(1):172. doi:10.1186/s12882-023-03214-1\u003c/li\u003e\n\u003cli\u003ePrskalo L, Skopnik CM, Goerlich N, et al. Urinary CD4+ T cells predict renal relapse in ANCA-associated vasculitis. \u003cem\u003eJ Am Soc Nephrol JASN\u003c/em\u003e. 2024;35(4):483-494. doi:10.1681/ASN.0000000000000311\u003c/li\u003e\n\u003cli\u003eFukuda A, Minakawa A, Kikuchi M, et al. Urinary podocyte mRNAs precede microalbuminuria as a progression risk marker in human type 2 diabetic nephropathy. \u003cem\u003eSci Rep\u003c/em\u003e. 2020;10:18209. doi:10.1038/s41598-020-75320-1\u003c/li\u003e\n\u003cli\u003eMesfine BB, Vojisavljevic D, Kapoor R, Watson D, Kandasamy Y, Rudd D. Urinary nephrin\u0026mdash;a potential marker of early glomerular injury: a systematic review and meta-analysis. \u003cem\u003eJ Nephrol\u003c/em\u003e. 2024;37(1):39-51. doi:10.1007/s40620-023-01585-0\u003c/li\u003e\n\u003cli\u003eGonzalez Guerrico AM, Lieske J, Klee G, et al. Urinary CD80 discriminates among glomerular disease types and reflects disease activity. \u003cem\u003eKidney Int Rep\u003c/em\u003e. 2020;5(11):2021-2031. doi:10.1016/j.ekir.2020.08.001\u003c/li\u003e\n\u003cli\u003eKostovska I, Tosheska Trajkovska K, Labudović D, Kostovski O. Urinary nephrin as an early biomarker of hypertensive nephropathy. \u003cem\u003eActa Clin Croat\u003c/em\u003e. 2023;62(4):635-643. doi:10.20471/acc.2023.62.04.8\u003c/li\u003e\n\u003cli\u003eKaneko T, Kodani E, Fujii H, Nakamura H, Sasabe H, Tamura Y. High body mass index and triglyceride levels at health checkups increase the risk of new-onset chronic kidney disease and worsening renal function: the TAMA MED project-CKD. \u003cem\u003eClin Exp Nephrol\u003c/em\u003e. 2024;28(10):1016-1026. doi:10.1007/s10157-024-02507-5\u003c/li\u003e\n\u003cli\u003eLin Z, Feng L, Zeng H, et al. Nomogram for the prediction of crescent formation in IgA nephropathy patients: a retrospective study. \u003cem\u003eBMC Nephrol\u003c/em\u003e. 2023;24(1):262. doi:10.1186/s12882-023-03310-2\u003c/li\u003e\n\u003cli\u003eZhu F, Gan W, Liu H, Chen W, Zeng X. Risk factors for renal progression in patients with CKD and coexisting COPD. \u003cem\u003eInt Urol Nephrol\u003c/em\u003e. 2025;57(3):885-895. doi:10.1007/s11255-024-04227-x\u003c/li\u003e\n\u003cli\u003eCheng T, Wang X, Han Y, Hao J, Hu H, Hao L. The level of serum albumin is associated with renal prognosis and renal function decline in patients with chronic kidney disease. \u003cem\u003eBMC Nephrol\u003c/em\u003e. 2023;24(1):57. doi:10.1186/s12882-023-03110-8\u003c/li\u003e\n\u003cli\u003eGao X, Suo Y, Zhang M, et al. Angiopoietin-like protein 3 markedly enhanced in the hyperlipidemia related proteinuria. \u003cem\u003eLipids Health Dis\u003c/em\u003e. 2019;18(1):116. doi:10.1186/s12944-019-1052-1\u003c/li\u003e\n\u003cli\u003eLi G, Lu D, Wang J, et al. ANGPTL3 is involved in kidney injury in high-fat diet-fed mice by suppressing ACTN4 expression. \u003cem\u003eLipids Health Dis\u003c/em\u003e. 2022;21(1):90. doi:10.1186/s12944-022-01700-3\u003c/li\u003e\n\u003cli\u003eKidney Disease Outcomes Quality Initiative (K/DOQI) Group. K/DOQI clinical practice guidelines for management of dyslipidemias in patients with kidney disease. \u003cem\u003eAm J Kidney Dis Off J Natl Kidney Found\u003c/em\u003e. 2003;41(4 Suppl 3):I-IV, S1-91.\u003c/li\u003e\n\u003cli\u003eYang P, Xiao Y, Luo X, et al. Inflammatory stress promotes the development of obesity-related chronic kidney disease via CD36 in mice. \u003cem\u003eJ Lipid Res\u003c/em\u003e. 2017;58(7):1417-1427. doi:10.1194/jlr.M076216\u003c/li\u003e\n\u003cli\u003ede Vries APJ, Ruggenenti P, Ruan XZ, et al. Fatty kidney: emerging role of ectopic lipid in obesity-related renal disease. \u003cem\u003eLancet Diabetes Endocrinol\u003c/em\u003e. 2014;2(5):417-426. doi:10.1016/S2213-8587(14)70065-8\u003c/li\u003e\n\u003cli\u003eGai Z, Wang T, Visentin M, Kullak-Ublick GA, Fu X, Wang Z. Lipid accumulation and chronic kidney disease. \u003cem\u003eNutrients\u003c/em\u003e. 2019;11(4):722. doi:10.3390/nu11040722\u003c/li\u003e\n\u003cli\u003eHe L, Hao L, Fu X, Huang M, Li R. Severe hypertriglyceridemia and hypercholesterolemia accelerating renal injury: a novel model of type 1 diabetic hamsters induced by short-term high-fat / high-cholesterol diet and low-dose streptozotocin. \u003cem\u003eBMC Nephrol\u003c/em\u003e. 2015;16:51. doi:10.1186/s12882-015-0041-5\u003c/li\u003e\n\u003cli\u003eMa Y, Chen Y, Xu H, Du N. The influence of angiopoietin-like protein 3 on macrophages polarization and its effect on the podocyte EMT in diabetic nephropathy. \u003cem\u003eFront Immunol\u003c/em\u003e. 2023;14:1228399. doi:10.3389/fimmu.2023.1228399\u003c/li\u003e\n\u003cli\u003eCao Y, Lin JH, Hammes HP, Zhang C. Cellular phenotypic transitions in diabetic nephropathy: an update. \u003cem\u003eFront Pharmacol\u003c/em\u003e. 2022;13:1038073. doi:10.3389/fphar.2022.1038073\u003c/li\u003e\n\u003cli\u003eYing Q, Wu G. Molecular mechanisms involved in podocyte EMT and concomitant diabetic kidney diseases: an update. \u003cem\u003eRen Fail\u003c/em\u003e. 2017;39(1):474-483. doi:10.1080/0886022X.2017.1313164\u003c/li\u003e\n\u003cli\u003eMa Y, Liu J, Liu H, Han X, Sun L, Xu H. Podocyte protection by Angptl3 knockout via inhibiting ROS/GRP78 pathway in LPS-induced acute kidney injury. \u003cem\u003eInt Immunopharmacol\u003c/em\u003e. 2022;105:108549. doi:10.1016/j.intimp.2022.108549\u003c/li\u003e\n\u003cli\u003eJi B, Liu J, Ma Y, et al. Minnelide combined with Angptl3 knockout completely protects mice with adriamycin nephropathy via suppression of TGF-\u0026beta;1-Smad2 and p53 pathways. \u003cem\u003eInt Immunopharmacol\u003c/em\u003e. 2023;115:109656. doi:10.1016/j.intimp.2022.109656\u003c/li\u003e\n\u003cli\u003eJi B, Liu J, Yin Y, Xu H, Shen Q, Yu J. Minnelide combined with anti-ANGPTL3-FLD monoclonal antibody completely protects mice with adriamycin nephropathy by promoting autophagy and inhibiting apoptosis. \u003cem\u003eCell Death Dis\u003c/em\u003e. 2023;14(9):601. doi:10.1038/s41419-023-06124-0\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003eTables 1 to 3 are available in the Supplementary Files section.\u003c/p\u003e "}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"journal-of-translational-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jtrm","sideBox":"Learn more about [Journal of Translational Medicine](http://translational-medicine.biomedcentral.com)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/jtrm/default.aspx","title":"Journal of Translational Medicine","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"ANGPTL3, Glomerular Diseases, Podocyte injury, Biomarker, Pediatric","lastPublishedDoi":"10.21203/rs.3.rs-8459364/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8459364/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground: \u003c/strong\u003ePodocyte injury is the pathological basis of various glomerular diseases, but noninvasive tools for assessing podocyte injury are still lacking at present. Angiopoietin-like protein 3 (ANGPTL3) has been proven to be pathologically elevated in glomerular diseases and associated with podocyte injury. The aim of this study was to evaluate the clinical utility of the urinary ANGPTL3-to-creatinine ratio (ANGPTL3/Cre) as a noninvasive biomarker for assessing podocyte injury in children with glomerular diseases.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMethods: \u003c/strong\u003eRenal ANGPTL3 expression was first examined in tissues from pediatric patients with podocyte injury (n=25) and controls (n=5), correlating it with established histological markers of podocyte injury and with urinary ANGPTL3 levels. Pediatric patients aged 1–18 years with glomerular diseases and healthy controls were subsequently enrolled and divided into a test set (n=346) and a validation set (n=150). ANGPTL3 levels in serum and urine were measured. Diagnostic performance was assessed using receiver operating characteristic (ROC) curves. Associations with podocyte injury and improvements in risk stratification were evaluated by logistic regression and reclassification improvement (NRI/IDI) analyses, respectively.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults:\u003c/strong\u003e Renal ANGPTL3 expression correlated negatively with podocyte injury markers P57Kip2 (\u003cem\u003er \u003c/em\u003e= -0.55, \u003cem\u003eP\u003c/em\u003e = 0.002) and synaptopodin (\u003cem\u003er \u003c/em\u003e= -0.37, \u003cem\u003eP\u003c/em\u003e = 0.04) and positively with urinary ANGPTL3/Cre (\u003cem\u003er\u003c/em\u003e = 0.64, \u003cem\u003eP\u003c/em\u003e \u0026lt; 0.001). Urinary ANGPTL3/Cre was significantly elevated in patients with podocyte injury and served as an independent risk factor for this condition (OR = 7.66, 95% CI: 2.27-25.84, \u003cem\u003eP\u003c/em\u003e= 0.001). It demonstrated superior diagnostic performance (area under the curve, AUC = 0.90 in both sets) compared to serum ANGPTL3 or traditional biomarkers. When combined with clinical variables, the AUC improved to 0.95 (95% CI: 0.93-0.97) with enhanced risk reclassification. High diagnostic efficacy (AUC = 0.88/0.86) was maintained even in patients with normal protein excretion.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion: \u003c/strong\u003eUrinary ANGPTL3/Cre is a reliable, noninvasive biomarker for podocyte injury in pediatric glomerular diseases. It effectively identifies subclinical injury in patients with normal protein excretion, showing strong potential for early screening and longitudinal monitoring.\u003c/p\u003e","manuscriptTitle":"Urinary ANGPTL3: A Novel Noninvasive Biomarker for Podocyte Injury in Pediatric Glomerular Diseases","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-19 15:38:42","doi":"10.21203/rs.3.rs-8459364/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewerAgreed","content":"","date":"2026-01-14T14:25:33+00:00","index":0,"fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-01-14T14:07:39+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-01-02T14:15:52+00:00","index":"","fulltext":""},{"type":"submitted","content":"Journal of Translational Medicine","date":"2025-12-30T23:00:03+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"journal-of-translational-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"jtrm","sideBox":"Learn more about [Journal of Translational Medicine](http://translational-medicine.biomedcentral.com)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/jtrm/default.aspx","title":"Journal of Translational Medicine","twitterHandle":"@BioMedCentral","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"254c55e6-60c4-4a8f-9f28-f038c9e238d2","owner":[],"postedDate":"January 19th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-03-22T14:21:13+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-19 15:38:42","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8459364","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8459364","identity":"rs-8459364","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}