Is the C4d, nephrin, and Wilms' tumor-1 staining pattern sensitive and specific for the differential diagnosis of focal segmental glomerulosclerosis and minimal change disease cases?

Is the C4d, nephrin, and Wilms' tumor-1 staining pattern sensitive and specific for the differential diagnosis of focal segmental glomerulosclerosis and minimal change disease cases? | 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 Is the C4d, nephrin, and Wilms' tumor-1 staining pattern sensitive and specific for the differential diagnosis of focal segmental glomerulosclerosis and minimal change disease cases? Esra Akcali, Kenan Turgutalp, Yasemin Yuyucu Karabulut, Zeynep Ebru Eser, and 6 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-1796559/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background: Differential diagnosis between minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS) is important because prognosis and treatment response of each disease is different. However, in some cases these two diseases cannot be distinguished from each other clinically and histopathologically. The aim of this study is to determine whether glomerular complement 4d (C4d), nephrin, Renal Wilms' tumor-1 (WT1) staining can be used to differentiate FSGS and MCD. Method: Patients with primary FSGS and MCD were included in the study. Specificity and sensitivity of C4d, nephrin, WT-1 staining was calculated for the diagnosis of FSGS and MCD. Results: Glomerular focal segmental C4d positivity (C4dP) was higher in FSGS compared to MCD patients. Nephrin staining positivity (NsP) was higher in MCD than FSGS patients (p<0.05). Specificity and sensitivity of glomerular C4dP for FSGS diagnose (85% and 73.9%) was higher compared to MCD (26.1% and 15.4%). Specificity and sensitivity of nephrin staining loss (NsLo) for FSGS diagnose (87% and 69%) was higher than MCD (30.8% and 13%). Specificity and sensitivity of coexistence of NsLo and C4dP (CoNsLo-C4dP) was higher in FSGS patients. Specificity and sensitivity of coexistence of NsP and C4d negativity (CoNsP-C4dN) was higher in MCD patients (100% and 77.8%). WT-1 was found neither specific nor sensitive for the differential diagnosis of FSGS and MCD. Conclusion: Glomerular C4dP and NsLo may be a method with high specificity and sensitivity in differentiating FSGS from MCD. CoNsLo-C4dP has the highest specificity and sensitivity for FSGS and CoNsP-C4dN for MCD. C4d nephrin WT1 focal segmental glomerulosclerosis Figures Figure 1 Figure 2 Figure 3 Background Focal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD) are the common forms of glomerular disease worldwide. Both diseases are entities that resemble each other and sometimes these two diseases cannot be distinguished from each other clinically and histopathologically [1]. There were some studies showing histopathological and urinary marker differences among FSGS and MCD patients -such as soluble urokinase receptor (suPAR) levels [2], podocyte Angptl4 staining in kidney biopsy specimen [3], α‑dystroglycan staining in kidney biopsy material [4] have been performed. IgG/albumin staining in protein reabsorption droplets was found correlate with histologic diagnosis in renal biopsies with MCD and FSGS [5]. Nephrin autoantibody is proposed for a new molecular classification of MCD [6]. But none of these studies emphasized whether these markers were specific or sensitive for FSGS or MCD. It has been proposed that both MCD and FSGS are a kind of T lymphocyte disorder [7]. It has been recently claimed that complement activation occurs in FSGS and it contributes to FSGS pathogenicity [8]. C4d is a product of complement cascade and its presence suggests complement activation [8]. Nephrin is the main component of the podocyte cytoskeleton. Although there are conflicting results, it is generally claimed that nephrin staining loss (NsLo) occurs in FSGS due to reduced mass of podocyte [9]. Renal Wilms' tumor-1 (WT-1) is a transcription factor critical for normal kidney development, and WT-1 staining loss (WT-1-SLo) is associated with many glomerular diseases such as FSGS. WT-1-SLo has been used to confirm podocyte injury [10]. C4d positivity (C4dP), NsLo and WT-1-SLo in biopsy material may be useful for differentiating between FSGS and MCD. Differential diagnosis between MCD and FSGS is important because prognosis and treatment response of each disease is different. We believe that new surrogate markers are needed to differ these two entities. The aim of this study is to determine whether glomerular C4d, nephrin, WT1 can be used to differentiate FSGS and MCD. In addition, we aim to determine whether each of these staining patterns are specific and sensitive to MCD and FSGS. Methods Study Design and Subjects This is a retrospective single center study, which was approved by Human Research Ethics Committee (08/01/2020, 2020/19) and it was performed in accordance with the guidelines of the Declaration of Helsinki. The patients who were 18 years old and older and admitted to the nephrology department between January 2013 and June 2020, diagnosed clinically and histopathologically as primary FSGS and MCD were included in the study. FSGS and MCD patients with a kidney transplant, and secondary FSGS cases were excluded. Other patients with glomerulonephritis including IgA nephropathy, lupus nephritis, pauci-immune glomerulonephritis, and membranous nephropathy, were also excluded from the study. Written informed consent was obtained from each participant The patients were divided into 3 groups: Group 1 was consisted of FSGS patients diagnosed by light microscopy (LM) and electron microscopy (EM). Group 2 included patients who had normal LM findings but FSGS and MCD couldn't be differential diagnosis by EM. Group 3 included MCD patients. Electron microscopy Electron microscopic examination of renal biopsy specimens were performed by a single histologist with more than 25 years’ experience (BCY). The tissues were fixed with 2.5% glutaraldehyde and 1% osmium tetroxide, and routine tissue processing procedure was performed for electron microscopic evaluation. Tissues were embedded in resin. Semithin sections (0.5–1.0 μm) and thin sections (70 nm) were collected for both light microscopy and TEM, respectively. Semithin sections were stained with 1% toluidine blue and viewed and photographed in an Olympus BX50 light microscope. Thin sections mounted on 200 mesh copper grids were contrasted with uranyl acetate and lead citrate for TEM and examined and photographed in a JEOL-JEM 1011 transmission electron microscope. Histopathological diagnosis of FSGS and MCD with electron microscopy If podocyte foot process effacement more than 70% and the presence of normal glomerular basement membrane (GBM), no immune deposits in EM was considered as MCD. In addition to podocyte foot process effacement, the podocyte and glomeruli structure abnormalities such as glomerular sclerosis, podocyte foot process focal detachments from the GBM, increased mesangial matrix and mesangial cells in the glomeruli, glomerular lipid droplet accumulation, wrinkling and thickening of GBM were considered as FSGS [11, 12]. Renal pathology C4d, WT1, nephrin staining in renal biopsy specimens were evaluated with LM by a single pathologist with more than 20 years of experience (YK). In the study, biopsy specimens with ≥8 glomeruli for LM, ≥2 glomeruli for direct immunofluorescence (DIF), and ≥1 glomerulus for EM, considered enough for evaluation. DIF assessment was based on IgM-C3 expression. The fluorescence intensity was determined using a semi-quantitative scale from 0 to 3: if 0, negative; 1 positive, weak staining; 2, mild staining; 3, severe staining [13]. Evaluation of biopsy specimens with LM, DIF and EM were performed as double-blind with having no information about clinical data of the patients. FSGS diagnosis with LM was defined as; having segmental sclerosis, Bowman's capsule adhesions, glomerular hypertrophy, focal and jumpy manner interstitial fibrosis (IF), tubular atrophy (TA) [14]. Materials were stained with haematoxylin-eosin, Periodic acid-schiff (PAS), periodic acid-methenamine silver (PAMS), Masson’s trichrome (M-T) and Congo-red. Immunohistochemical staining with C4d (clone SP91), WT1 (clone 6F-H2), and nephrin (clone PA5-32515) antibodies were also evaluated. Pathological findings of glomerular, tubular, interstitial and vessels were defined. TA was scored as normal 50%. IF was scored as normal 50% [15]. The location of glomerular C4dP considering mesangial and/or focal segmental as well as WT-1 staining positivity and nephrin staining positivity (NsP) and NsLo were evaluated. C4dP, WT-1-SLo and NsLo were correlated with segmental sclerosis, global sclerosis, glomerular hypertrophy, IF, TA in patient with FSGS. C4dP in MCD patients was correlated with diffuse effacement (>70%) of pedicels with EM findings. All staining patterns were also correlated with histomorphological findings. Specificity, sensitivity, positive predictive value (PPV) and negative predictive value (NPV) of C4dP, NsLo and WT-1-SLo was calculated for both FSGS and MCD diagnosis. The specificity and sensitivity of coexistence of NsLo and C4dP (CoNsLo-C4dP) and coexistence of NsP and C4d negativity (CoNsP-C4dN) for diagnosis of FSGS and MCD in the biopsy specimen were calculated. Association between C4dP, NsLo, C4dN, NsP, CoNsLo-C4dP, CoNsP-C4dN and patological findings - podocyte foot process effacement >70%, wrinkling and thickening of GBM, increased mesangial matrix and mesangial cells in the glomeruli, podocyte foot process focal detachments from the GBM, glomerular lipid droplet accumulation- were evaluated. Data collection Clinical data’s were collected from the hospital electronic medical record system. Age, gender, systolic and diastolic blood pressure, fasting blood glucose, serum urea and creatinine levels during kidney biopsy, estimated glomerular filtration rate (eGFR) [Calculated by CKD-EPI formulas {(141 × min ( creatinine /κ, 1) α × max(creatinine/κ, 1)-1.209 × 0.993Year × 1.018 [if women] × 1.159 [if black]. GFR: ml/min/1.73 m2 [Scr]: creatinine, mg/dl)] [16], serum albumin, 24 hours proteinuria, hematuria, uric acid, serum complement C3, C4 levels were evaluated. Statistical analyses Statistical analyses were conducted using IBM SPSS Statistics for Windows, Version 26.0 (IBM Corp., Armonk, NY, USA). Categorical variables were described as numbers and percentages, and continuous variables were expressed as median and interquartile ranges (25-75%). The normality of the variables was determined using visual methods (histograms and probability plots) and Kolmogorov-Smirnov tests. The Chi-square test was used for two or multiple group comparisons of categorical variables, and independent t-test or Mann-Whitney U test was used if appropriate for comparison of numerical variables. In addition, we used ANOVA test for normally distributed numerical variables and Kruskal-Wallis test for non-normally distributed numerical variables, in multi-group comparisons. p<0.05 was accepted as the significance level. Results In total, one hundred fourteen adequate biopsy specimens were included in the study (Group 1: 23, group 2: 78, group 3: 13 patients). The mean age of the all subjects was 44.5/years, and 55% of them were women. Hypoalbuminemia, proteinuria, low density lipoprotein (LDL) levels were higher in group 3 compared to the other groups (p<0.05). No significant difference was found between the groups in terms of the eGFR (p<0.05). The biochemical and demographic characteristics of the groups were shown in table 1. Histomorphological findings There was no difference in terms of glomeruli number between the groups. IgM and C3 staining severity were higher in FSGS than other groups. Global and segmental sclerosis, Bowman’s capsule adhesion was higher in group 1 than others (p<0.05). C3 staining with DIF evaluation was higher in group 1 than others. There was no significant difference in terms of IF and TA between group 1 and 2. Glomerular C4dP was higher in group 1 compared to group 2 and 3. The patients with glomerular focal segmental C4dP was higher in group 1 compared to group 2 and 3 (p<0.05). NsP was higher in group 3 than group 1 patients (p<0.05). NsLo was higher in group 1 patients compared to group 3. There was no difference between the groups in terms of WT1 staining. CoNsLo-C4dP was higher in group 1 than other groups (p<0.05). CoNsP-C4dN was higher in group 3 compared to group 1. 33% of group 2 patients had CoNsLo-C4dP, whereas 35% had CoNsP-C4dN. CoNsP-C4dN was not found in 51 patients (65%) of group 2. Pathologic findings of groups were shown in Table 2. Staining patterns of glomerulus with nephrin and C4d was shown in figure 1a, 1b, 1c, 1d Specificity and sensitivity of C4dP, WT-1-SLo and NsLo for FSGS and MCD diagnosis The specificity and sensitivity of glomerular C4dP were higher for FSGS (85% and 73.9%) diagnosis than MCD (26.1% and 15.4%). Specificity and sensitivity of NsLo were higher for FSGS (87% and 69%) diagnosis than MCD (30.8% and 13%). WT-1-SLo was found neither specific nor sensitive for the differential diagnosis of FSGS and MCD (85% vs 60.9% and 39.1% vs 15.4%). Coexistence of staining patterns CoNsLo-C4dP was higher in group 1 than others. However, CoNsLo-C4dP was higher in group 2 compared to group3 (p<0.05). While CoNsP-C4dN was higher in group 3 than group 1 (p<0.05), there was no difference between group 2 and 3. Specificity and sensitivity of CoNsLo-C4dP was higher in FSGS patients (77.8% and 100%) compared to MCD (0% and 22.2%). Specificity and sensitivity of CoNsP-C4dN was higher in MCD patients (100% and 77.8%) compared to FSGS (22.2% and 0%). Specificity and sensitivity of glomerular C4dP, WT-1-SLo, NsLo, CoNsLo-C4dP and CoNsP-C4dN in FSGS and MCD were shown in figure 2a, 2b, 2c, 2d, 2e PPV and NPV values of C4dP and WT-1-SLo, NsLo for FSGS and MCD diagnosis Positive prevalence value (PPV) and negative prevalence value (NPV) of C4dP for FSGS and MCD diagnosis were found as 89.5% vs 10. 5% and 64.7% vs 35.3% respectively. PPV and NPV values of NsLo for FSGS and MCD diagnosis were found as 83.3% vs 16.7% and 75% vs 25% respectively. PPV and NPV values of WT-1-SLo for FSGS and MCD diagnosis were found as 81.8 % vs 18.2% and 44% vs 56% respectively. PPV and NPV values of C4d, nephrin and WT1 for FSGS and MCD diagnosis were shown in figure 3a, 3b, 3c Renal histomorphological lesions with EM Increased mesangial matrix and mesangial cells in the glomeruli, podocyte foot process focal detachments from the GBM was higher in group 1 patients compared to group 3. Wrinkling and thickening of GBM was higher in group 1 than group 2 and 3 patients (p70% were higher in group 3 patients than group 1 patients and group 2. There was no difference between group 1 patients and group 2 in terms of podocyte foot process effacement >70%, increased mesangial matrix and mesangial cells in the glomeruli. Histologic findings with EM of groups were shown in Table 3. Factors related with C4dP, WT-1-SLo, NsLo, CoNsLo-C4dP and CoNsP-C4dN Glomerular C4dP was found to be associated with the presence of global or segmental sclerosis in the glomerulus, Bowman's capsule adhesions, the presence of IF and IgM and C3 accumulation in DIF, wrinkling and thickening of GBM and podocyte foot process focal detachments from the GBM in EM (p<0.05). WT-1-SLo was found to be associated with Bowman's capsule adhesions, IgM deposition and C3 deposition. (p<0.05). NsLo was found to be related with global or segmental sclerosis in LM and glomerular lipid droplet accumulation, podocyte foot process focal detachments from the GBM, wrinkling and thickening of GBM, in EM (p<0.05). CoNsLo-C4dP was found to be related with podocyte foot process effacement, wrinkling and thickening of GBM, podocyte foot process focal detachments from the GBM in EM, presence of global or segmental sclerosis in the glomerulus. CoNsP-C4dN CoNsP-C4dN was not found related with the presence of global or segmental sclerosis in the glomerulus, Bowman's capsule adhesions, wrinkling and thickening of GBM and podocyte foot process focal detachments from the GBM, lipid droplet accumulation. Discussion In this study, we examined diagnostic performances of C4d, nephrin and WT1 staining to distinguish FSGS from MCD. There are a few studies showing that complement activation may also play a role in FSGS patients in addition to T cell activation. However, no studies have been conducted to determine whether C4d, nephrin and coexistence staining is specific and sensitive in FSGS and MCD. This is the first study that glomerular C4dP and NsLo were found as highly specific, sensitive and had high PPV and NPV for FSGS. C4dN and NsP were found high specific and sensitive for MCD. In this study, it was shown that the CoNsLo-C4dP has the highest specificity and sensitivity for the diagnosis of FSGS but not MCD, and the CoNsP-C4dN for the diagnosis of MCD but not FSGS. In the current study, we detected focal segmental C4dP 65.2% of patient with FSGS. However, focal segmental C4dP was not detected in any of the MCD group. Similarly, in this study, NsLo was observed more in FSGS patients than MCD. Nephrin positive staining was more common in MCD patients than in FSGS patients. WT-1-SLo was not different between the FSGS and MCD groups. Findings about podocytes were quite similar in MCD and FSGS. MCD and FSGS both showed foot process effacement. FSGS was diagnosed primarily by LM and DIF, and EM confirmed the widespread effacement of foot processes of the podocytes and was more likely to be focal [17]. However, in MCD, podocytes had diffuse foot process effacement in EM. Podocytes are separated from the GBM and leaving uncovered the GBM areas in FSGS. Bared GBM is exposed to contact with the parietal epithelium, leading to focal glomerulosclerosis [18]. Other features more suggestive of FSGS were foot process separation from the GBM, hyaline deposits in the mesangium and occasionally in the capillary lumen/subendothelial area, and intraluminal foam cells. Although MCD and FSGS can generally differentiated by histopathological findings, in some cases, because of renal cortical region biopsy sampling, MCD may resemble early primary FSGS, due to inability to see foot process effacement [19]. The differential diagnostic markers defined in previous studies between FSGS and MDH are extremely rare. None of the study results have been validated with a strong studies. Most of studies have concentrated on identifying a circulating factor as well as urine, serum and histopathological marker in either MCD or FSGS. However, few studies have compared these markers in MCD and FSGS. The histopathological and urine marker differences between FSGS and MCD have been shown in some studies. It was declared that suPAR levels were higher in patients with FSGS than in those with MCD [2]. Podocyte Angptl4 staining in biopsy specimen has been reported from patients with MCD, but not in samples from patients with FSGS [3]. It was reported that podocyte-specific B7‑1 expression was high in the patients with MCD and FSGS, but it was not a specific marker for MCD or FSGS [20]. There was conflicting result about α‑dystroglycan staining in biopsy materials. Decreased α‑dystroglycan staining has been reported in patients with MCD compared with FSGS patients [4]. In another study, no difference was found in α‑dystroglycan expression between patients with MCD and those FSGS [21]. Hodgin et al. reported that the ratio of podocin to synaptopodin mRNA expression was higher in patients with FSGS compared to MCD [22]. Although some of these markers were found to be high in FSGS and some in MCD, none of them were reported to be specific and sensitive to FSGS or MCD. Therefore, there is a need for an alternate marker that can be both specific and sensitive to FSGS and MCD and can be used for the differential diagnosis between FSGS and MCD. The role of complement activation in various glomerular diseases, particularly the alternate pathway activation. C4dP was shown a result of C4 activation in classical and/or lectin complement pathway [8]. Glomerular IgM and C3 deposition are commonly shown in primary FSGS [23]. Previous studies showed that complement activation is involved in various glomerular diseases such as lupus nephritides, membranous glomerulonephritis, IgA nephropathy, membranoproliferative glomerulonephritis, lupus nephritis, Anti-neutrophilic cytoplasmic antibody-associated glomerulonephritis, anti-glomerular basement membrane disease, thrombotic microangiopathy, C3 glomerulopathy [8]. However, no studies showing that differential diagnosis can be made between MCD and FSGS patients by examining complement activation and C4d deposition in human kidney biopsy material. C4dP helps to describe complement activation pathways in some glomerular diseases and to understand the disease pathogenesis and differential diagnosis. T-lymphocyte dysfunction has been suggested in both MCD and FSGS [7]. In addition to T lymphocyte dysfunction, animal studies suggest that complement activation has pathogenetic role in FSGS [24]. Lest et all. found in their study that, glomerular C4d deposits appear before the development of FSGS using a rat model of transplant FSGS. They detected that C4d positivity was predominant in the glomerular mesangium in a patient with FSGS [1]. Heybeli et al. showed that mesangial C4d deposition is an independent predictor of disease progression and treatment failure in patients with primary FSGS [25]. In a study by Drachenberg et al., while C4d was negative in 62% of patients in MCD, they obtained C4dP in sclerotic lesions in 100% of FSGS patients. In their study, it was not specified whether C4dP was specific or sensitive to FSGS disease [26]. In our study, focal segmental C4dP was significantly higher in FSGS compared to MCD patients. There was no difference between group 2 and 3 patients in terms of mesangial C4dP. However, mesangial C4dP was higher in FSGS group compared to others. We thought that mesangial C4d deposition might have occurred before development of FSGS lesions. Additionally, the severity of IgM and C3 staining was higher in FSGS patients compared to MCD. Glomerular C4dP was associated with IgM and C3 accumulation as well as presence of global or segmental sclerosis. Nephrin is the major component of the slit diaphragm that connects the pedicel of the podocytes [27]. Nephrin has been studied in MCD with inconsistent results. Various researches have shown that the glomerular nephrin expression in MCD is not different than normal control groups [28, 29]. In contrast, reduced amounts of nephrin mRNA in glomeruli in several MCD patients were found in Furness et al. study [30]. The reason of decrease in nephrin expression in FSGS patient may be the presence of circulating plasma factors [31]. It may be an adverse effect on nephrin expression in human podocytes. NsLo in these patients is likely to result in the development of focal segmental glomerulosclerosis before podocyte injury develops. We found that NsLo was correlated with segmental sclerosis and connective tissue accumulation. NsLo was higher in FSGS patient compared to MCD as well as have higher sensitivity and specificity for FSGS diagnosis in our study. Therefore, we think that the use of nephrin staining would be beneficial in patients who cannot be differentiated whether as having MCD or FSGS. WT-1 is a well-known transcription factor important for the maintenance of normal podocyte function, and WT-1-SLo is associated with many glomerular diseases including FSGS [10]. WT-1-SLo has been used to confirm podocyte injury in kidney biopsy [32]. Zhou et al. stated in their study that urinary exosomal WT-1 differ between FSGS and non-FSGS patients [10]. In our study, there was no difference in terms of WT-1-SLo between FSGS, MCD and indeterminate patients. Although WT-1-SLo was found to be associated with Bowman's capsule adhesions, IgM deposition and C3 deposition, WT-1-SLo was not specific or sensitive to FSGS or MCD in our study. One possible explanation for these differences between their results and ours is that WT1 is technically studied with different methods in both studies. WT-1 levels were studied in urine by the ELISA in Zhou et al study, however WT1 staining was evaluated in the biopsy tissue by DIF method in our study. If differential diagnosis cannot be succeeded between FSGS and MCD patients, CoNsLo-C4dP and/or CoNsP-C4dN may be helpful for differential diagnosis. In this study, specificity and sensitivity of glomerular C4dP for the FSGS diagnose was higher compared to MCD. The CoNsLo-C4dP has the highest specificity (77%) and sensitivity (100%) for FSGS diagnosis. In group 2, we obtained to CoNsLo-C4dP in 26 patients (33%). In other words, we thought that 26 of these 78 patients in group 2, which was comprised of patients who couldn’t be differentiated histopathologically whether they had FSGS or MCD, had FSGS CoNsP-C4dN has the highest specificity (100%) and sensitivity (77%) for MCD diagnosis . In Group 2, we detected CoNsP-C4dN in 27 patients (35%). We believed that these patients had MCD. CoNsP-C4dN was not detected in 51 patients (65%) in group 2. Thus, we thought that 51 patients had FSGS in group 2. The small number of patients and the retrospective design are the first limitations of our study. Second, we did not examine the response to treatment and prognostic processes of both FSGS and MCD patients with and without C4d and nephrin staining. In conclusions, glomerular C4dP and NsLo may be a method with high specificity and sensitivity in differentiating FSGS from MCD. CoNsLo-C4dP has the highest specificity and sensitivity for FSGS and CoNsP-C4dN for MCD. However, there is need for randomized studies with larger study groups. Abbreviations MCD:minimal change disease, FSGS: focal segmental glomerulosclerosis, WT1: Renal Wilms' tumor-1, C:complement, C4dP: C4d positivity, NsP:Nephrin staining positivity, NsLo: nephrin staining loss, CoNsLo-C4dP: coexistence of NsLo and C4d pozitivity, CoNsP-C4dN: coexistence of NsP and C4d negativity, WT-1-SLo: WT-1 staining loss, suPAR: soluble urokinase receptor, LM: light microscopy, EM: electron microscopy, GBM: glomerular basement membrane, DIF: direct immunofluorescence, PAS: Periodic acid-schiff, PAMS: periodic acid-methenamine silver, M-T: Masson’s trichrome, eGFR: estimated glomerular filtration rate, LDL: low density lipoprotein, IF: interstitial fibrosis, TA: tubular atrophy. Declarations Ethics Approval and Consent to Participate Our study was approved by Human Research Ethics Committee (08/01/2020, 2020/19) and it was performed in accordance with the guidelines of the Declaration of Helsinki. Written informed consent was obtained from each participant. Availability of data and materials The datasets used and/or analysed during the current study available from the corresponding author on reasonable request. Competing interests The authors declare no conflicts of interest. Funding Sources Mersin University Scientific Research Project. Author details 1 Mersin University Faculty of Medicine, Department of Internal Medicine, Division of Nephrology, Mersin, Turkey . 2 Mersin University Faculty of Medicine, Department of Pathology, Mersin, Turkey. 3 Mersin University Faculty of Medicine, Department of Histology and Embryology, Mersin, Turkey. 4 Burhan Nalbantoglu State Hospital, Nephrology Department Nicosia, Turkish Republic of Northern Cyprus. 5 Istanbul University, Istanbul Faculty of Medicine, Department of Internal Medicine, Division of Nephrology, Istanbul, Turkey. Authors' contributions E.A and K.T wrote the main manuscript text, Y.Y.K and O.A.M prepared the pathologic materials, S.O and S.B made statiscal analized, B.C.Y made elecrtron microscobic research, Z.E.E, S.D and A.A.K reviewed article Acknowledgement: We thank to Mersin University Scientific Research Project for financial support. 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CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration): A new equation to estimate glomerular filtration rate. Ann Intern Med. 2009 May 5;150(9):604-12. Ponticelli C, Glassock RJ. 2nd edn. 2010.Treatment of primary glomerulonephritis, Oxford University Press, New York; p.181. Mubarak M, Kazi J. Study of nephrotic syndrome in children: importance of light, immunoflourescence and electron microscopic observations to a correct classification of glomerulopathies. Nefrologia. 2013;33:237–42. Rivera A, Magliato S, Meleg-Smith S. Value of electron microscopy in the diagnosis of childhood nephrotic syndrome. Ultrastruct Pathol. 2001 Jul-Aug;25(4):313-20 Novelli, R. Gagliardini, E. Ruggiero, B. Benigni, A. Remuzzi, G. Any value of podocyte B7‑1 as a biomarker in human MCD and FSGS? Am. J. Physiol. Renal Physiol. 2016 Mar 1;310(5):F335-41. Vogtländer NP, van der Vlag J, Bakker MA, Dijkman HB, Wevers RA, Campbell KP, et al. Expression of sialidase and dystroglycan in human glomerular diseases. Nephrol. Dial. Transplant. 2010 Feb;25(2):478-84. Hodgin JB, Borczuk AC, Nasr SH, Markowitz GS, Nair V, Martini S, et al. A molecular profile of focal segmental glomerulosclerosis from formalin-fixed, paraffin-embedded tissue. Am. J. Pathol. 2010 Oct;177(4):1674-86. Zhang YM, Gu QH, Huang J, Qu Z, Wang X, Meng LQ, Wang F, et al. Clinical Significance of IgM and C3 Glomerular Deposition in Primary Focal Segmental Glomerulosclerosis. Clin J Am Soc Nephrol. 2016 Sep 7;11(9):1582-9. Hsu SI-Hong, Couser WG. Chronic progression of tubulointerstitial damage in proteinuric renal disease is mediated by complement activation: a therapeutic role for complement inhibitors? J Am Soc Nephrol. 2003 Jul;14(7 Suppl 2):S186-91. Heybeli C, Oktan MA, Yıldız S, Ünlü M, Celik A, Sarıoglu S. Mesangial C4d deposition is independently associated with poor renal survival in patients with primary focal segmental glomerulosclerosis. Clin Exp Nephrol. 2019 May;23(5):650-660. Drachenberg CB, Papadimitriou JC, Chandra P, Haririan A, Mendley S, Weir MR, et al. Epidemiology and Pathophysiology of Glomerular C4d Staining in Native Kidney Biopsies. Kidney Int Rep. 2019 Jul 30;4(11):1555-1567 Jennette J.C, Olson J.L, Silva F.G, D'Agati V.D. Renal Anatomy and Histology. 7th ed. Heptinstall Pathology of the Kidney 2014 Aug;1:11-144. Wernerson A, Dunér F, Pettersson E, Widholm SM, Berg U, Ruotsalainen V, et al. Altered ultrastructural distribution of nephrin in minimal change nephrotic syndrome. Nephrol Dial Transplant. 2003 Jan;18:70–76. Patrakka J, Ruotsalainen V, Ketola I, Holmberg C, Heikinheimo M, Tryggvason K, et al. Expression of nephrin in pediatric kidney diseases. J Am Soc Nephrol. 2001 Feb;12(2):289-296. Furness PN, Hall LL, Shaw JA, Pringle JH. Glomerular expression of nephrin is decreased in acquired human nephrotic syndrome. Nephrol Dial Transplant. 1999 May; 14:1234–1237. 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Tables Table 1: Biochemical and demographic characteristics of the groups Group 1 (n:23) Group 2 (n:78) Group 3 (n:13) Age (Year) 39 (25-51) a 45 (35-60) a 45 (37-52) a Gender (Female), n(%) 11 (20.0) a 39 (70.9) a 5 (9.1) a SBP (mmHg) 133 (120-142) a 130 (121-147) a 129 (121-147) a DBP (mmHg) 85 (72-100) a 80(75-90) a 81 (77-88) a Glucose (mg/dL) 97 (86-118) a 96.5 (88-112) a 94 (91-104) a Creatinine (mg/dL) 1.15 (1-2) a 0.9 (1-1) b 0.9 (1-1) a.b eGFR (ml/dk/1.73m 2 ) 67 (42-112) a 91 (57-114) a 91 (41-107) a Albumin (gr/dL) 3.7 (2-4) b 3.8 (3-4) b 1.6 (1-2) a 24-hour proteinuria (gr) 6.6 (3-9) a 3.5 (2-4) b 9.1 (4-11) a Serum C3 (mg/dL) 122 (100-142) b 122 (101-145) b 140 (125-181) a Serum C4 (mg/dL) 31 (27-43) b 28 (21-33) c 45 (35-49) a Hematuria, n(%) 13 (56.5) a,b 31 (39.7) b 11 (84.6) a Abbreviations: Values in the same row not sharing the same superscript are significantly different at p<0.05 eGFR: estimating Glomerular filtration rate, C: Complement, SBP: systolic blood pressure, DBP: diastolic blood pressure Table 2: Pathological features of the groups with LM and DIF Group 1 (n:23) Group 2 (n:78) Group 3 (n:13) Number of glomeruli* (median) 9(5-14) a 8(6-12) a 10(10-15) a Segmental sclerosis, n (%) Yes 17 (73.9) a 15 (19.2) b 0(0) No 6 (26.1) a 63 (80.8) b 13(100.0) Global sclerosis, n (%) Yes 17 (73.9) b 39(50.0) ab 3 (23.1) a No 6 (26.1) b 39(50.0) ab 10 (76.9) a Bowman's capsule adhesions, n (%) Yes 14 (60.9) b 18 (23.1) a 1 (7.7) a No 9 (39.1) b 60 (76.9) a 12 (92.3) a EDD in the mesangium, n (%) Yes 10 (43.5) a 30 (38.5) a 3 (23.1) a No 13 (56.5) a 48 (61.5) a 10 (76.9) a Glomerular hypertrophy, n (%) Yes 13 (56.5) b 34 (43.6) b 1 (7.7) a No 10 (43.5) b 44 (56.4) b 12 (92.3) a Interstitial fibrosis, n (%) No 10 (43.5) a 44 (56.4) a 13(100.0) Mild 10 (43.5) a 31 (39.7) a 0(0) Moderate 3 (13.0) a 3 (3.8) a 0(0) Severe 0(0) 0(0) 0(0) Tubular atrophy, n(%) Yes 12 (52.2) a 28 (35.9) a 0(0) No 11 (47.8) a 50 (64.1) a 13(100.0) Ig M, n (%) + 11 (47.8) a 11 (14.1) b 4 (30.8) ab ++ 5 (21.7) a 6 (7.7) a 0(0) +++ 0(0) 0(0) 0(0) No 7 (30.4) a 61 (78.2) b 9 (69.2) ab C3, n (%) + 5 (21.7) a 4 (5.1) b 1 (7.7) ab ++ 8 (34.8) a 7 (9.0) b 2 (15.4) ab +++ 1 (4.3) a 1 (1.3) a 0(0) No 9 (39.1) a 66 (84.6) b 10 (76.9) ab WT1, n (%) Staining P 14 (60.9) a 57 (73.1) a 11 (84.6) a Staining loss 9 (39.1) a 21 (26.9) a 2 (15.4) a Nephrin, n (%) Staining P 3 (13.0) b 38 (48.7) a 9 (69.2) a Staining loss 20 (87.0) b 40 (51.3) a 4 (30.8) a C4d, n (%) Staining P 17 (73.9) b 25 (32) a 2(15.4) a FSS 13 (56) a 14 (17.9) b 0(0) MS 4 (17.3) a 11 (14.1) a 2 (15.4) a Staining N 6 (26.1) b 53 (67.9) a 11 (84.6) a Coexistence staining pattern, n (%) CoNsLo-C4dP 16 (69.6) a 26 (33) b 0 (0) ab CoNsP-C4dN 2 (9) b 27 (35) a 7 (54) a Note: Values in the same row not sharing the same superscript are significantly different at p<0.05 Abbreviations: LM, Light microscopy; DIF, direct immunofluorescence; GBM: glomerular basement membrane, WT1, Wilms tumor1, C3, Complement 3; Ig M, Immunoglobulin M; EDD, electron-dense deposits; Staining P, staining positivity; Staining N, staining negativity; FSS, Focal segmental staining; MS, Mesangial staining; CoNsLo-C4dP, coexistence of nephrin staining loss and C4d positivity; CoNsP-C4dN, coexistence of nephrin staining positivity and C4d negativity Table 3. Histologically findings of groups with EM Group 1 Group 2 Group 3 Podocyte foot process effacement >%70, n (%) yes 10 (43.5) a 26 (33.3) a 13(100.0) no 13 (56.5) a 52 (66.7) a 0(0) Wrinkling and thickening of GBM, n (%) yes 8 (34.8) a 5 (6.4) b 2 (15.4) a.b no 15 (65.2) a 73 (93.6) b 11 (84.6) a.b Increased mesangial matrix and mesangial cells in the glomeruli , n (%) yes 20 (87.0) b 55 (70.5) b 4 (30.8) a no 3 (13.0) b 23 (29.5) b 9 (69.2) a Podocyte foot process focal detachments from the GBM, n (%) yes 18 (78.3) b 49 (62.8) b 2 (15.4) a no 5 (21.7) b 29 (37.2) b 11 (84.6) a Glomerular lipid droplet accumulation, n (%) yes 4 (17.4) a 16 (20.5) a 0(0) no 19 (82.6) a 62 (79.5) a 13(100.0) Note: Values in the same row not sharing the same superscript are significantly different at p<0.05 Abbreviations: EM, Electron microscopy; GBM, glomerular basement membrane Additional Declarations No competing interests reported. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-1796559","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":120709572,"identity":"32be3758-a07e-416a-a2a7-29ce7809324e","order_by":0,"name":"Esra Akcali","email":"","orcid":"","institution":"Mersin University","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Esra","middleName":"","lastName":"Akcali","suffix":""},{"id":120709573,"identity":"77480a41-cb23-4dbf-b004-0f2721d31f79","order_by":1,"name":"Kenan 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1","display":"","copyAsset":false,"role":"figure","size":100769,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ea.\u003c/strong\u003e Segmental C4d positivity (immunohistochemical staining in FSGSx40)\u003c/p\u003e\u003cp\u003e\u003cstrong\u003e\u0026nbsp;b.\u003c/strong\u003e Normal Glomeruli (C4d negative) immunohistochemical stainig x40\u003c/p\u003e\u003cp\u003e\u003cstrong\u003ec.\u003c/strong\u003e Segmental nephrin staining loss (immunohistochemical staining in FSGS)\u003c/p\u003e\u003cp\u003e\u003cstrong\u003ed.\u003c/strong\u003e Normal glomeruli (MCD) nephrin staining positivity in DIF\u003c/p\u003e","description":"","filename":"Figure1.1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1796559/v1/21e2939d6610792e8c2cb70f.jpg"},{"id":24150578,"identity":"ee58c674-73ec-4648-a1d6-9e3bcca6d893","added_by":"auto","created_at":"2022-07-21 16:26:46","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":201265,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ea. \u003c/strong\u003eSpecificity and sensitivity of glomerular C4d positivity for FSGS and MCD \u003cstrong\u003eb.\u003c/strong\u003e Specificity and sensitivity of nephrin staining loss for FSGS and MCD \u003cstrong\u003ec.\u003c/strong\u003e Specificity and sensitivity of WT1 staining loss for FSGS and MCD \u003cstrong\u003ed.\u003c/strong\u003e Specificity and sensitivity of CoNsLo-C4dP for FSGS and MCD \u003cstrong\u003ee.\u003c/strong\u003e Specificity and sensitivity of CoNsP-C4dN for FSGS and MCD\u003c/p\u003e","description":"","filename":"Figure2.1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1796559/v1/8e2c7e72551f2808d46fe2f7.jpg"},{"id":24150379,"identity":"933731c4-0bf0-40d4-b264-972d9238af1d","added_by":"auto","created_at":"2022-07-21 16:21:46","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":113303,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ea-\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/strong\u003ePPV and NPV values of C4d positivity in FSGS and MCD\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eb-\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/strong\u003ePPV and NPV values of nephrin staining loss in FSGS and MCD\u003c/p\u003e\u003cp\u003e\u003cstrong\u003ec-\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003c/strong\u003ePPV and NPV values of WT1 staining loss in FSGS and MCD\u003c/p\u003e","description":"","filename":"Figure3.1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-1796559/v1/cec2de4765fd7789607e9be3.jpg"},{"id":25413508,"identity":"627d6e54-4c14-4b4f-bf97-e136336a8461","added_by":"auto","created_at":"2022-08-19 13:14:39","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":814906,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-1796559/v1/b3891bd9-a2b7-4470-bb37-cfd840a92060.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Is the C4d, nephrin, and Wilms' tumor-1 staining pattern sensitive and specific for the differential diagnosis of focal segmental glomerulosclerosis and minimal change disease cases?","fulltext":[{"header":"Background","content":"\u003cp\u003eFocal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD) are the common forms of glomerular disease worldwide.\u0026nbsp;Both diseases are entities that resemble each other and sometimes these two diseases cannot be distinguished from each other clinically and histopathologically\u0026nbsp;[1].\u003c/p\u003e\n\u003cp\u003eThere were some studies showing histopathological and urinary marker differences among FSGS and MCD patients -such as soluble urokinase receptor (suPAR) levels\u0026nbsp;[2], podocyte Angptl4 staining in kidney biopsy specimen\u0026nbsp;[3], \u0026alpha;‑dystroglycan staining in kidney biopsy material\u0026nbsp;[4]\u0026nbsp;have been performed. IgG/albumin staining in\u0026nbsp;protein reabsorption droplets was found correlate with histologic diagnosis in renal biopsies with MCD and FSGS\u0026nbsp;[5]. Nephrin autoantibody is proposed for a new molecular classification of MCD\u0026nbsp;[6].\u0026nbsp;But none of these studies emphasized whether these markers were specific or sensitive for FSGS or MCD. It has been proposed that both MCD and FSGS are a kind of T lymphocyte disorder\u0026nbsp;[7]. It has been recently claimed that complement activation occurs in FSGS and it contributes to FSGS pathogenicity\u0026nbsp;[8].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eC4d is a product of complement cascade and its presence suggests complement activation\u0026nbsp;[8]. Nephrin is the main component of the podocyte cytoskeleton. Although there are conflicting results, it is generally claimed that nephrin staining loss (NsLo) occurs in FSGS due to reduced mass of podocyte\u0026nbsp;[9]. Renal Wilms\u0026apos; tumor-1 (WT-1) is a transcription factor critical for normal kidney development, and WT-1 staining loss (WT-1-SLo) is associated with many glomerular diseases such as FSGS. WT-1-SLo has been used to confirm podocyte injury\u0026nbsp;[10].\u0026nbsp;C4d positivity (C4dP), NsLo and WT-1-SLo in biopsy material may be useful for differentiating between FSGS and MCD.\u003c/p\u003e\n\u003cp\u003eDifferential diagnosis between MCD and FSGS is important because prognosis and treatment response of each disease is different.\u0026nbsp;We believe that new surrogate markers are needed to differ these two entities.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe aim of this study is to determine whether glomerular C4d, nephrin, WT1 can be used to differentiate FSGS and MCD. In addition, we aim to determine whether each of these staining patterns are specific and sensitive to MCD and FSGS.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eStudy Design and Subjects\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis is a retrospective single center study, which was approved by Human Research Ethics Committee (08/01/2020, 2020/19) and it was performed in accordance with the guidelines of the Declaration of Helsinki.\u0026nbsp;The patients who were 18 years old and older and admitted to the nephrology department between January 2013 and June 2020, diagnosed clinically and histopathologically as primary FSGS and MCD were included in the study. FSGS and MCD patients with a kidney transplant, and secondary FSGS cases were excluded.\u0026nbsp;Other patients with glomerulonephritis including IgA nephropathy, lupus nephritis, pauci-immune glomerulonephritis, and membranous nephropathy, were also excluded from the study.\u0026nbsp;Written informed consent was obtained from each participant\u003c/p\u003e\n\u003cp\u003eThe patients were divided into 3 groups: Group 1 was consisted of FSGS patients diagnosed by light microscopy (LM) and electron microscopy (EM). Group 2 included patients who had normal LM findings but FSGS and MCD couldn\u0026apos;t be differential diagnosis by EM. Group 3 included MCD patients.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eElectron microscopy\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eElectron microscopic examination of renal biopsy specimens were performed by a single histologist with more than 25 years\u0026rsquo; experience (BCY). The tissues were fixed with 2.5% glutaraldehyde and 1% osmium tetroxide, and routine tissue processing procedure was performed for electron microscopic evaluation.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eTissues were embedded in resin. Semithin sections (0.5\u0026ndash;1.0 \u0026mu;m) and thin sections (70 nm) were collected for both light microscopy and TEM, respectively. Semithin sections were stained with 1% toluidine blue and viewed and photographed in an Olympus BX50 light microscope. Thin sections mounted on 200 mesh copper grids were contrasted with uranyl acetate and lead citrate for TEM and examined and photographed in a JEOL-JEM 1011 transmission electron microscope.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eHistopathological diagnosis of FSGS and MCD with electron microscopy\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIf podocyte foot process effacement more than 70% and the presence of normal glomerular basement membrane (GBM), no immune deposits in EM was considered as MCD. In addition to podocyte foot process effacement, \u0026nbsp;the podocyte and glomeruli structure abnormalities such as glomerular sclerosis, podocyte foot process focal detachments from the GBM, increased mesangial matrix and mesangial cells in the glomeruli, glomerular lipid droplet accumulation, wrinkling and thickening of GBM were considered as FSGS [11, 12].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRenal pathology\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eC4d, WT1, nephrin staining in renal biopsy specimens were evaluated with LM by a single pathologist with more than 20 years of experience (YK). In the study, biopsy specimens with \u0026ge;8 glomeruli for LM, \u0026ge;2 glomeruli for direct immunofluorescence (DIF), and \u0026ge;1 glomerulus for EM, considered enough for evaluation. DIF assessment was based on IgM-C3 expression. The fluorescence intensity was determined using a semi-quantitative scale from 0 to 3: if 0, negative; 1 positive, weak staining; 2, mild staining; 3, severe staining [13].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eEvaluation of biopsy specimens with LM, DIF and EM were performed as double-blind with having no information about clinical data of the patients.\u003c/p\u003e\n\u003cp\u003eFSGS diagnosis with LM was defined as; having segmental sclerosis, Bowman\u0026apos;s capsule adhesions, glomerular hypertrophy, focal and jumpy manner interstitial fibrosis (IF), tubular atrophy (TA) [14].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eMaterials were stained with haematoxylin-eosin, Periodic acid-schiff (PAS), periodic acid-methenamine silver (PAMS), Masson\u0026rsquo;s trichrome (M-T) and Congo-red. \u0026nbsp; Immunohistochemical staining with C4d (clone SP91), WT1 (clone 6F-H2), and nephrin (clone PA5-32515) antibodies were also evaluated. Pathological findings of glomerular, tubular, interstitial and vessels were defined.\u003c/p\u003e\n\u003cp\u003eTA was scored as normal \u0026lt;10%, mild 10%-25%, moderate 25%-50%, severe\u0026gt;50%. IF was scored as normal \u0026lt;10%, mild 10%-25%, moderate 25%-50%, severe\u0026gt;50% [15]. The location of glomerular C4dP considering mesangial and/or focal segmental as well as WT-1 staining positivity and nephrin staining positivity (NsP) and NsLo were evaluated.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eC4dP, WT-1-SLo and NsLo were correlated with segmental sclerosis, global sclerosis, glomerular hypertrophy, IF, TA in patient with FSGS. C4dP in MCD patients was correlated with diffuse effacement (\u0026gt;70%) of pedicels with EM findings. All staining patterns were also correlated with histomorphological findings. Specificity, sensitivity, positive predictive value (PPV) and negative predictive value (NPV) of C4dP, NsLo and WT-1-SLo was calculated for both FSGS and MCD diagnosis.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe specificity and sensitivity of coexistence of NsLo and C4dP (CoNsLo-C4dP) and coexistence of NsP and C4d negativity (CoNsP-C4dN) for diagnosis of FSGS and MCD in the biopsy specimen were calculated.\u003c/p\u003e\n\u003cp\u003eAssociation between C4dP, NsLo, C4dN, NsP, CoNsLo-C4dP, CoNsP-C4dN and patological findings - podocyte foot process effacement \u0026gt;70%, wrinkling and thickening of GBM, increased mesangial matrix and mesangial cells in the glomeruli, podocyte foot process focal detachments from the GBM, glomerular lipid droplet accumulation- were evaluated.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData collection\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eClinical data\u0026rsquo;s were collected from the hospital electronic medical record system. Age, gender, systolic and diastolic blood pressure, fasting blood glucose, serum urea and creatinine levels during kidney biopsy, estimated glomerular filtration rate (eGFR) [Calculated by CKD-EPI formulas {(141 \u0026times; min ( creatinine /\u0026kappa;, 1) \u0026alpha; \u0026times; max(creatinine/\u0026kappa;, 1)-1.209 \u0026times; 0.993Year \u0026times; 1.018 [if women] \u0026times; 1.159 [if black]. \u0026nbsp;GFR: ml/min/1.73 m2 \u0026nbsp; [Scr]: creatinine, \u0026nbsp; mg/dl)] [16], serum albumin, 24 hours proteinuria, hematuria, uric acid, serum complement C3, C4 levels were evaluated.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eStatistical analyses\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eStatistical analyses were conducted using IBM SPSS Statistics for Windows, Version 26.0 (IBM Corp., Armonk, NY, USA). Categorical variables were described as numbers and percentages, and continuous variables were expressed as median and interquartile ranges (25-75%). The normality of the variables was determined using visual methods (histograms and probability plots) and Kolmogorov-Smirnov tests. The Chi-square test was used for two or multiple group comparisons of categorical variables, and independent t-test or Mann-Whitney U test was used if appropriate for comparison of numerical variables. In addition, we used ANOVA test for normally distributed numerical variables and Kruskal-Wallis test for non-normally distributed numerical variables, in multi-group comparisons. p\u0026lt;0.05 was accepted as the significance level. \u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eIn total, one hundred fourteen adequate biopsy specimens were included in the study (Group 1: 23, group 2: 78, group 3: 13 patients). The mean age of the all subjects was 44.5/years, and 55% of them were women. Hypoalbuminemia, proteinuria, low density lipoprotein (LDL) levels were higher in group 3 compared to the other groups (p\u0026lt;0.05). No significant difference was found between the groups in terms of the eGFR (p\u0026lt;0.05). The biochemical and demographic characteristics of the groups were shown in table 1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eHistomorphological findings\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere was no difference in terms of glomeruli number between the groups. IgM and C3 staining severity were higher in FSGS than other groups. Global and segmental sclerosis, Bowman\u0026rsquo;s capsule adhesion was higher in group 1 than others (p\u0026lt;0.05). C3 staining with DIF evaluation was higher in group 1 than others. There was no significant difference in terms of IF and TA between group 1 and 2.\u003c/p\u003e\n\u003cp\u003eGlomerular C4dP was higher in group 1 compared to group 2 and 3. The patients with glomerular focal segmental C4dP was higher in group 1 compared to group 2 and 3 (p\u0026lt;0.05). \u0026nbsp; NsP was higher in group 3 than group 1 patients (p\u0026lt;0.05). NsLo was higher in group 1 patients compared to group 3. There was no difference between the groups in terms of WT1 staining.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eCoNsLo-C4dP was higher in group 1 than other groups (p\u0026lt;0.05). CoNsP-C4dN was higher in group 3 compared to group 1. 33% of group 2 patients had CoNsLo-C4dP, whereas 35% had CoNsP-C4dN. CoNsP-C4dN was not found in 51 patients (65%) of group 2.\u003c/p\u003e\n\u003cp\u003ePathologic findings of groups were shown in Table 2. Staining patterns of glomerulus with nephrin and C4d was shown in figure 1a, 1b, 1c, 1d \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSpecificity and sensitivity of C4dP, WT-1-SLo and NsLo for FSGS and MCD diagnosis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe specificity and sensitivity of glomerular C4dP were higher for FSGS (85% and 73.9%) diagnosis than MCD (26.1% and 15.4%). Specificity and sensitivity of NsLo were higher for FSGS (87% and 69%) diagnosis than MCD (30.8% and 13%). WT-1-SLo was found neither specific nor sensitive for the differential diagnosis of FSGS and MCD\u0026nbsp;(85% vs 60.9% and 39.1% vs 15.4%).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCoexistence of\u0026nbsp;staining patterns\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eCoNsLo-C4dP was higher in group 1 than others. However, CoNsLo-C4dP was higher in group 2 compared to group3 (p\u0026lt;0.05). While CoNsP-C4dN was higher in group 3 than group 1 (p\u0026lt;0.05), there was no difference between group 2 and 3.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSpecificity and sensitivity of CoNsLo-C4dP was higher in FSGS patients (77.8% and 100%) compared to MCD (0% and 22.2%). Specificity and sensitivity of CoNsP-C4dN was higher in MCD patients (100% and 77.8%) compared to FSGS (22.2% and 0%).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSpecificity and sensitivity of glomerular C4dP, WT-1-SLo, NsLo, CoNsLo-C4dP and CoNsP-C4dN in FSGS and MCD were shown in figure 2a, 2b, 2c, 2d, 2e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePPV and NPV values of C4dP and WT-1-SLo, NsLo for FSGS and MCD diagnosis\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003ePositive prevalence value (PPV) and negative prevalence value (NPV) of C4dP for FSGS and MCD diagnosis were found as 89.5% vs 10. 5% and 64.7% vs 35.3% respectively.\u003c/p\u003e\n\u003cp\u003ePPV and NPV values of NsLo for FSGS and MCD diagnosis were found as 83.3% vs 16.7% and 75% vs 25% respectively.\u003c/p\u003e\n\u003cp\u003ePPV and NPV values of WT-1-SLo for FSGS and MCD diagnosis were found as 81.8 % vs 18.2% and 44% vs 56% respectively.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003ePPV and NPV values of C4d, nephrin and WT1 for FSGS and MCD diagnosis\u0026nbsp;were shown in figure 3a, 3b, 3c\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eRenal histomorphological lesions with EM\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIncreased mesangial matrix and mesangial cells in the glomeruli, podocyte foot process focal detachments from the GBM was higher in group 1 patients compared to group 3. Wrinkling and thickening of GBM was higher in group 1 than group 2 and 3 patients (p\u0026lt;0.05). Podocyte foot process effacement \u0026gt;70% were higher in group 3 patients than group 1 patients and group 2. There was no difference between group 1 patients and group 2 in terms of podocyte foot process effacement \u0026gt;70%, increased mesangial matrix and mesangial cells in the glomeruli. Histologic findings with EM of groups were shown in Table 3.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFactors related with C4dP, WT-1-SLo, NsLo, CoNsLo-C4dP and CoNsP-C4dN\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eGlomerular C4dP was found to be associated with the presence of global or segmental sclerosis in the glomerulus, Bowman\u0026apos;s capsule adhesions, the presence of IF and IgM and C3 accumulation in DIF, wrinkling and thickening of GBM and podocyte foot process focal detachments from the GBM in EM (p\u0026lt;0.05). WT-1-SLo was found to be associated with Bowman\u0026apos;s capsule adhesions, IgM deposition and C3 deposition. (p\u0026lt;0.05). NsLo was found to be related with global or segmental sclerosis in LM and glomerular lipid droplet accumulation, podocyte foot process focal detachments from the GBM, wrinkling and thickening of GBM, in EM (p\u0026lt;0.05).\u0026nbsp;CoNsLo-C4dP was found to be related with podocyte foot process effacement, wrinkling and thickening of GBM, podocyte foot process focal detachments from the GBM in EM, presence of global or segmental sclerosis in the glomerulus. CoNsP-C4dN\u003c/p\u003e\n\u003cp\u003eCoNsP-C4dN was not found related with the presence of global or segmental sclerosis in the glomerulus, Bowman\u0026apos;s capsule adhesions, wrinkling and thickening of GBM and podocyte foot process focal detachments from the GBM, lipid droplet accumulation.\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eIn this study, we examined diagnostic performances of C4d, nephrin and WT1 staining to distinguish FSGS from MCD. There are a few studies showing that complement activation may also play a role in FSGS patients in addition to T cell activation. However, no studies have been conducted to determine whether C4d, nephrin and coexistence staining is specific and sensitive in FSGS and MCD. This is the first study that glomerular C4dP and NsLo were found as highly specific, sensitive and had high PPV and NPV\u003cem\u003e\u0026nbsp;\u003c/em\u003efor\u003cem\u003e\u0026nbsp;\u003c/em\u003eFSGS. C4dN and NsP were found high specific and sensitive for MCD. In this study, it was shown that the CoNsLo-C4dP has the highest specificity and sensitivity for the diagnosis of FSGS but not MCD, and the CoNsP-C4dN for the diagnosis of MCD but not FSGS.\u003c/p\u003e\n\u003cp\u003eIn the current study, we detected focal segmental C4dP 65.2% of patient with FSGS. However, focal segmental C4dP was not detected in any of the MCD group.\u0026nbsp;Similarly, in this study, NsLo was observed more in FSGS patients than MCD. Nephrin positive staining was more common in MCD patients than in FSGS patients. WT-1-SLo was not different between the FSGS and MCD groups.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFindings about podocytes were quite similar in MCD and FSGS. MCD and FSGS both showed foot process effacement. FSGS was diagnosed primarily by LM and DIF, and EM confirmed the widespread effacement of foot processes of the podocytes and was more likely to be focal\u0026nbsp;[17]. However, in MCD, podocytes had diffuse foot process effacement in EM. Podocytes are separated from the GBM and leaving uncovered the GBM areas in FSGS. Bared GBM is exposed to contact with the parietal epithelium, leading to focal glomerulosclerosis\u0026nbsp;[18]. Other features more suggestive of FSGS were foot process separation from the GBM, hyaline deposits in the mesangium and occasionally in the capillary lumen/subendothelial area, and intraluminal foam cells. Although MCD and FSGS can generally differentiated by histopathological findings, in some cases, because of renal cortical region biopsy sampling, MCD may resemble early primary FSGS, due to inability to see foot process effacement\u0026nbsp;[19].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe differential diagnostic markers defined in previous studies between FSGS and MDH are extremely rare. None of the study results have been validated with a strong studies. Most of studies have concentrated on identifying a circulating factor as well as urine, serum and histopathological marker in either MCD or FSGS. However, few studies have compared these markers in MCD and FSGS. The histopathological and urine marker differences between FSGS and MCD have been shown in some studies. It was declared that suPAR levels were higher in patients with FSGS than in those with MCD\u0026nbsp;[2].\u0026nbsp;Podocyte Angptl4 staining in biopsy specimen has been reported from patients with MCD, but not in samples from patients with FSGS\u0026nbsp;[3]. It was reported that podocyte-specific B7‑1 expression was high in the patients with MCD and FSGS, but it was not a specific marker for MCD or FSGS\u0026nbsp;[20]. There was conflicting result about \u0026alpha;‑dystroglycan staining in biopsy materials. Decreased \u0026alpha;‑dystroglycan staining has been reported in patients with MCD compared with FSGS patients\u0026nbsp;[4]. In another study, no difference was found in \u0026alpha;‑dystroglycan expression between patients with MCD and those FSGS\u0026nbsp;[21]. Hodgin et al. reported that the ratio of podocin to synaptopodin mRNA expression was higher in patients with FSGS compared to MCD\u0026nbsp;[22]. Although some of these markers were found to be high in FSGS and some in MCD, none of them were reported to be specific and sensitive to FSGS or MCD. Therefore, there is a need for an alternate marker that can be both specific and sensitive to FSGS and MCD and can be used for the differential diagnosis between FSGS and MCD.\u003c/p\u003e\n\u003cp\u003eThe role of complement activation in various glomerular diseases, particularly the alternate pathway\u0026nbsp;activation. C4dP was shown a result of C4 activation in classical and/or lectin complement pathway\u0026nbsp;[8].\u0026nbsp;Glomerular IgM and C3 deposition are commonly shown in primary FSGS\u0026nbsp;[23].\u0026nbsp;Previous studies showed that complement activation is involved in various glomerular diseases such as lupus nephritides, membranous glomerulonephritis, IgA nephropathy, membranoproliferative glomerulonephritis, lupus nephritis, Anti-neutrophilic cytoplasmic antibody-associated glomerulonephritis, anti-glomerular basement membrane disease, thrombotic microangiopathy, C3 glomerulopathy\u0026nbsp;[8]. However, no studies showing that differential diagnosis can be made between MCD and FSGS patients by examining complement activation and C4d deposition in human kidney biopsy material. C4dP helps to describe complement activation pathways in some glomerular diseases and to understand the disease pathogenesis and differential diagnosis.\u0026nbsp;T-lymphocyte dysfunction has been suggested in both MCD and FSGS\u0026nbsp;[7]. In addition to T lymphocyte dysfunction, animal studies suggest that complement activation has pathogenetic role in FSGS\u0026nbsp;[24]. Lest et all. found in their study that, glomerular C4d deposits appear before the development of FSGS using a rat model of transplant FSGS. They detected that C4d positivity was predominant in the glomerular mesangium in a patient with FSGS\u0026nbsp;[1]. Heybeli et al. showed that mesangial C4d deposition is an independent predictor of disease progression and treatment failure in patients with primary FSGS\u0026nbsp;[25]. In a study by Drachenberg et al., while C4d was negative in 62% of patients in MCD, they obtained C4dP in sclerotic lesions in 100% of FSGS patients. In their study, it was not specified whether C4dP was specific or sensitive to FSGS disease\u0026nbsp;[26]. In our study, focal segmental C4dP was significantly higher in FSGS compared to MCD patients. There was no difference between group 2 and 3 patients in terms of mesangial C4dP. However, mesangial C4dP was higher in FSGS group compared to others. We thought that mesangial C4d deposition might have occurred before development of FSGS lesions. Additionally, the severity of IgM and C3 staining was higher in FSGS patients compared to MCD. Glomerular C4dP was associated with IgM and C3 accumulation as well as presence of global or segmental sclerosis.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eNephrin\u0026nbsp;is the major component of the slit diaphragm that connects the pedicel of the podocytes\u0026nbsp;[27]. Nephrin has been studied in MCD with inconsistent results. Various researches have shown that the glomerular nephrin expression in MCD is not different than normal control groups\u0026nbsp;[28, 29].\u0026nbsp;In contrast, reduced amounts of nephrin mRNA in glomeruli in several MCD patients were found in Furness et al. study\u0026nbsp;[30]. The reason of decrease in nephrin expression in FSGS patient may be the presence of circulating plasma factors\u0026nbsp;[31].\u0026nbsp;It may be an adverse effect on nephrin expression in human podocytes. NsLo in these patients is likely to result in the development of focal segmental glomerulosclerosis before podocyte injury develops. We found that NsLo was correlated with segmental sclerosis and connective tissue accumulation. NsLo was higher in FSGS patient compared to MCD as well as have higher sensitivity and specificity for FSGS diagnosis in our study. Therefore, we think that the use of nephrin staining would be beneficial in patients who cannot be differentiated whether as having MCD or FSGS.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eWT-1 is a well-known transcription factor important for the maintenance of normal podocyte function, and WT-1-SLo is associated with many glomerular diseases including FSGS\u0026nbsp;[10]. WT-1-SLo has been used to confirm podocyte injury in kidney biopsy\u0026nbsp;[32]. Zhou et al. stated in their study that urinary exosomal WT-1 differ between FSGS and non-FSGS patients\u0026nbsp;[10]. In our study, there was no difference in terms of WT-1-SLo between FSGS, MCD and indeterminate patients. Although WT-1-SLo was found to be associated with Bowman\u0026apos;s capsule adhesions, IgM deposition and C3 deposition, WT-1-SLo was not specific or sensitive to FSGS or MCD in our study.\u0026nbsp;One possible explanation for these differences between their results and ours is that WT1 is technically studied with different methods in both studies. WT-1 levels were studied in urine by the ELISA in Zhou et al study, however WT1 staining was evaluated in the biopsy tissue by DIF method in our study.\u003c/p\u003e\n\u003cp\u003eIf differential diagnosis cannot be succeeded between FSGS and MCD patients, CoNsLo-C4dP and/or CoNsP-C4dN may be helpful for differential diagnosis. In this study, specificity and sensitivity of glomerular C4dP for the FSGS diagnose was higher compared to MCD. The CoNsLo-C4dP has the highest specificity (77%) and sensitivity (100%) for FSGS diagnosis. In group 2, we obtained to CoNsLo-C4dP in 26 patients (33%). In other words, we thought that 26 of these 78 patients in group 2, which was comprised of patients who couldn\u0026rsquo;t be differentiated histopathologically whether they had FSGS or MCD, had FSGS CoNsP-C4dN has the highest specificity (100%) and sensitivity (77%) for MCD diagnosis . In Group 2, we detected CoNsP-C4dN in 27 patients (35%). We believed that these patients had MCD. CoNsP-C4dN was not detected in 51 patients (65%) in group 2. Thus, we thought that 51 patients had FSGS in group 2.\u003c/p\u003e\n\u003cp\u003eThe small number of patients and the retrospective design are the first limitations of our study. Second, we did not examine the response to treatment and prognostic processes of both FSGS and MCD patients with and without C4d and nephrin staining.\u003c/p\u003e\n\u003cp\u003eIn conclusions,\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003eglomerular C4dP and NsLo may be a method with high specificity and sensitivity in differentiating FSGS from MCD. CoNsLo-C4dP has the highest specificity and sensitivity for FSGS and CoNsP-C4dN for MCD. However, there is need for randomized studies with larger study groups.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eMCD:minimal change disease, FSGS: focal segmental glomerulosclerosis, WT1: Renal Wilms\u0026apos; tumor-1, C:complement, C4dP: C4d positivity, NsP:Nephrin staining positivity, NsLo: nephrin staining loss, CoNsLo-C4dP: coexistence of NsLo and C4d pozitivity, CoNsP-C4dN: coexistence of NsP and C4d negativity, WT-1-SLo: WT-1 staining loss, suPAR: soluble urokinase receptor, LM: light microscopy, EM: electron microscopy, GBM: glomerular basement membrane, DIF: direct immunofluorescence, PAS: Periodic acid-schiff, PAMS: periodic acid-methenamine silver, M-T: Masson\u0026rsquo;s trichrome, eGFR: estimated glomerular filtration rate, LDL: low density lipoprotein, IF: interstitial fibrosis, TA: tubular atrophy.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics Approval and Consent to Participate \u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eOur study was approved by Human Research Ethics Committee (08/01/2020, 2020/19) and it was performed in accordance with the guidelines of the Declaration of Helsinki. Written informed consent was \u0026nbsp;obtained from each participant.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analysed during the current study available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eThe authors declare no conflicts of interest.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding Sources\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMersin University Scientific Research Project.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor details\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eMersin University Faculty of Medicine, Department of Internal Medicine, Division of Nephrology, Mersin, Turkey\u003cstrong\u003e.\u0026nbsp;\u003c/strong\u003e\u003csup\u003e2\u003c/sup\u003eMersin University Faculty of Medicine, Department of Pathology, Mersin, Turkey. \u003csup\u003e3\u003c/sup\u003eMersin University Faculty of Medicine, Department of Histology and Embryology, Mersin, Turkey. \u003csup\u003e4\u003c/sup\u003eBurhan Nalbantoglu State Hospital, Nephrology Department Nicosia, Turkish Republic of Northern Cyprus. \u003csup\u003e5\u003c/sup\u003eIstanbul University, Istanbul Faculty of Medicine, Department of Internal Medicine, Division of Nephrology, Istanbul, Turkey.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026apos; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eE.A and K.T wrote the main manuscript text, Y.Y.K and O.A.M prepared the pathologic materials, S.O and S.B made statiscal analized, B.C.Y made elecrtron microscobic research, Z.E.E, S.D and A.A.K reviewed article\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgement:\u0026nbsp;\u003c/strong\u003eWe thank to Mersin University Scientific Research Project for financial support. The preliminary study was orally presented in 16\u003csup\u003eth\u003c/sup\u003e BANTAO Congress (Balkan Association of Nephrology, Dialysis, Transplantation and Artificial Organs), Tirana, Albania, 29-31 October 2021 and received the 3\u003csup\u003erd\u003c/sup\u003e prize.\u003cstrong\u003e\u003cbr\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e"},{"header":"References","content":"\u003col class=\"decimal_type\"\u003e\n \u003cli\u003eLest van de N.A, Zandbergen M, Wolterbeek R, Kreutz R, Trouw L.A, Dorresteijn E.M, et al. Glomerular C4d deposition can precede the development of focal segmental glomerulosclerosis. Kidney international. 2019 Sep;96(3):738-749.\u003c/li\u003e\n \u003cli\u003eWei C, El Hindi S, Li J, Fornoni A, Goes N, Sageshima J,\u0026nbsp;et al. Circulating urokinase receptor as a cause of focal segmental glomerulosclerosis. Nat. Med. 2011 Jul 31;17(8):952-60.\u003c/li\u003e\n \u003cli\u003eClement LC, Avila-Casado C, Mac\u0026eacute; C, Soria E, Bakker WW, Kersten S,\u0026nbsp;et al. Podocyte-secreted angiopoietinlike‑4 mediates proteinuria in glucocorticoid-sensitive nephrotic syndrome. Nat. Med. 2011 Jan;17(1):117-22.\u003c/li\u003e\n \u003cli\u003eGiannico G, Yang H, Neilson EG, Fogo AB.\u0026nbsp;Dystroglycan in the diagnosis of FSGS. Clin. J. Am. Soc. Nephrol.\u0026nbsp;2009 Nov;4(11):1747-53.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eBu L, Mirocha J, Haas M. Immunoglobulin G/albumin staining in tubular protein reabsorption droplets in minimal change disease and focal segmental glomerulosclerosis. Nephrol Dial Transplant 2021 May 27;36(6):1016-1022\u003c/li\u003e\n \u003cli\u003eWatts AJB, Keller KH, Lerner G, Rosales I, Collins AB, Sekulic M, et al. Discovery of Autoantibodies Targeting Nephrin in Minimal Change Disease Supports a Novel Autoimmune Etiology. J Am Soc Nephrol 2022 Jan;33(1):238-252\u003c/li\u003e\n \u003cli\u003eCho MH, Hong EH, Lee TH, Ko CW. Pathophysiology of minimal change nephrotic syndrome and focal segmental glomerulosclerosis. Nephrology (Carlton). 2007 Dec;12 Suppl 3:S11-4\u003c/li\u003e\n \u003cli\u003eChandra P. C4d in Native Glomerular Diseases. Am J Nephrol 2019 Jan;49(1):81-92\u003c/li\u003e\n \u003cli\u003eVerma R, Venkatareddy M, Kalinowski A, Li T, Kukla J, Mollin A, et al.\u0026nbsp;Nephrin is necessary for podocyte recovery following injury in an adult mature glomerulus. PLoS One 2018 Jun 20;13(6):e0198013\u003c/li\u003e\n \u003cli\u003eZhou H, Kajiyama H, Tsuji T, Hu X, Leelahavanichkul A, Vento S, et al.\u0026nbsp;Urinary exosomal Wilms\u0026rsquo; tumor-1 as a potential biomarker for podocyte injury. Am J Physiol Renal Physiol 2013 Aug 15;305(4):F553-9.\u003c/li\u003e\n \u003cli\u003eDiagnostic Electron Microscopy: A Text/Atlas Chapter 12, Renal Glomer\u0026uuml;lar Disease Shamila Mauiyyedi, Martin K. Selig, Alain P. Marion, Robert B. Colvin pp:786-8\u003c/li\u003e\n \u003cli\u003eMathieson PW. Minimal change nephropathy and focal segmental glomerulosclerosis. Semin Immunopathol 2007 Nov;29(4):415-26.\u003c/li\u003e\n \u003cli\u003eZhang YM, Gu QH, Huang J, Qu Z, Wang X, Meng LQ, et al. Clinical Significance of IgM and C3 Glomerular Deposition in Primary Focal Segmental Glomerulosclerosis. Clin J Am Soc Nephrol. 2016 Sep 7;11(9):1582-9.\u003c/li\u003e\n \u003cli\u003eColvin RB, \u003ca href=\"https://www.amazon.com/s/ref=dp_byline_sr_book_2?ie=UTF8\u0026field-author=Anthony+Chang\u0026text=Anthony+Chang\u0026sort=relevancerank\u0026search-alias=books\"\u003e\u0026nbsp;Chang\u003c/a\u003e A. Diagnostic pathology: kidney disease. 3rd ed. 2019\u003c/li\u003e\n \u003cli\u003eLiu J, Xie J, Zhang X, Tong J, Hao X, Ren H, et al. Serum C3 and renal outcome in patients with primary focal segmental glomerulosclerosis. Sci Rep. 2017 Jun 22;7(1):4095.\u003c/li\u003e\n \u003cli\u003eLevey AS, Stevens LA, Schmid CH, Zhang YL, Castro AF, Feldman HI, et al. CKD-EPI (Chronic Kidney Disease Epidemiology Collaboration): A new equation to estimate glomerular filtration rate. Ann Intern Med.\u0026nbsp;2009 May 5;150(9):604-12.\u003c/li\u003e\n \u003cli\u003ePonticelli C, Glassock RJ. 2nd edn. 2010.Treatment of primary glomerulonephritis, Oxford University Press, New York; p.181.\u003c/li\u003e\n \u003cli\u003eMubarak M, Kazi J. Study of nephrotic syndrome in children: importance of light, immunoflourescence and electron microscopic observations to a correct classification of glomerulopathies. Nefrologia. 2013;33:237\u0026ndash;42.\u003c/li\u003e\n \u003cli\u003eRivera A, Magliato S, Meleg-Smith S. Value of electron microscopy in the diagnosis of childhood nephrotic syndrome. Ultrastruct Pathol. 2001 Jul-Aug;25(4):313-20\u003c/li\u003e\n \u003cli\u003eNovelli, R. Gagliardini, E. Ruggiero, B. Benigni, A. Remuzzi, G. Any value of podocyte B7‑1 as a biomarker in human MCD and FSGS? Am. J. Physiol. Renal Physiol. 2016 Mar 1;310(5):F335-41.\u003c/li\u003e\n \u003cli\u003eVogtl\u0026auml;nder NP, van der Vlag J, Bakker MA, Dijkman HB, Wevers RA, Campbell KP,\u0026nbsp;et al. Expression of sialidase and dystroglycan in human glomerular diseases. Nephrol. Dial. Transplant. 2010 Feb;25(2):478-84.\u003c/li\u003e\n \u003cli\u003eHodgin JB, Borczuk AC, Nasr SH, Markowitz GS, Nair V, Martini S,\u0026nbsp;et al. A molecular profile of focal segmental glomerulosclerosis from formalin-fixed, paraffin-embedded tissue. Am. J. Pathol. 2010 Oct;177(4):1674-86.\u003c/li\u003e\n \u003cli\u003eZhang YM, Gu QH, Huang J, Qu Z, Wang X, Meng LQ, Wang F, et al.\u0026nbsp;Clinical Significance of IgM and C3 Glomerular Deposition in Primary Focal Segmental Glomerulosclerosis. Clin J Am Soc Nephrol. 2016 Sep 7;11(9):1582-9.\u003c/li\u003e\n \u003cli\u003eHsu SI-Hong, Couser WG. Chronic progression of tubulointerstitial damage in proteinuric renal disease is mediated by complement activation: a therapeutic role for complement inhibitors? J Am Soc Nephrol. 2003 Jul;14(7 Suppl 2):S186-91.\u003c/li\u003e\n \u003cli\u003eHeybeli C, Oktan MA, Yıldız S, \u0026Uuml;nl\u0026uuml; M, Celik A, Sarıoglu S.\u0026nbsp;Mesangial C4d deposition is independently associated with poor renal survival in patients with primary focal segmental glomerulosclerosis. Clin Exp Nephrol. 2019 May;23(5):650-660.\u003c/li\u003e\n \u003cli\u003eDrachenberg CB, Papadimitriou JC, Chandra P, Haririan A, Mendley S, Weir MR, et al. Epidemiology and Pathophysiology of Glomerular C4d Staining in Native Kidney Biopsies. Kidney Int Rep. 2019 Jul 30;4(11):1555-1567\u003c/li\u003e\n \u003cli\u003eJennette J.C, \u0026nbsp;Olson J.L, Silva F.G, D\u0026apos;Agati V.D. Renal Anatomy and Histology. 7th ed. Heptinstall Pathology of the Kidney 2014 Aug;1:11-144.\u003c/li\u003e\n \u003cli\u003eWernerson A, Dun\u0026eacute;r F, Pettersson E, Widholm SM, Berg U, Ruotsalainen V,\u0026nbsp;et al. Altered ultrastructural distribution of nephrin in minimal change nephrotic syndrome. Nephrol Dial Transplant. 2003 Jan;18:70\u0026ndash;76.\u003c/li\u003e\n \u003cli\u003ePatrakka J, Ruotsalainen V, Ketola I, Holmberg C, Heikinheimo M, Tryggvason K, et al. Expression of nephrin in pediatric kidney diseases. J Am Soc Nephrol. 2001 Feb;12(2):289-296.\u003c/li\u003e\n \u003cli\u003eFurness PN, Hall LL, Shaw JA, Pringle JH. Glomerular expression of nephrin is decreased in acquired human nephrotic syndrome. Nephrol Dial Transplant. 1999 May; 14:1234\u0026ndash;1237.\u003c/li\u003e\n \u003cli\u003eWang SX, Rastaldi MP, Patari A, Ahola H, Heikkila E, Holthofer H. Patterns of nephrin and a new proteinuria-associated protein expression in human renal diseases. Kidney Int. 2002 Jan; 61: 141\u0026ndash;147.\u003c/li\u003e\n \u003cli\u003eSu J, Li SJ, Chen ZH, Zeng CH, Zhou H, Li LS, et al. Evaluation of podocyte lesion in patients with diabetic nephropathy: Wilms\u0026rsquo; tumor-1 protein used as a podocyte marker. Diabetes Res Clin Pract. 2010 Feb; 87: 167\u0026ndash;175.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Tables","content":"\u003cp\u003e\u003cstrong\u003eTable 1:\u003c/strong\u003e Biochemical and demographic characteristics of the groups\u003c/p\u003e\n\u003ctable border=\"1\" cellpadding=\"0\" cellspacing=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"29.677419354838708%\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.838709677419356%\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroup 1\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n:23)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.29032258064516%\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroup 2\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n:78)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.193548387096776%\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroup 3\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; (n:13)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.677419354838708%\"\u003e\n \u003cp\u003e\u003cstrong\u003eAge (Year)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.838709677419356%\"\u003e\n \u003cp\u003e39 (25-51)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.29032258064516%\"\u003e\n \u003cp\u003e45 (35-60)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.193548387096776%\"\u003e\n \u003cp\u003e45 (37-52)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.677419354838708%\"\u003e\n \u003cp\u003e\u003cstrong\u003eGender\u0026nbsp;(Female), n(%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.838709677419356%\"\u003e\n \u003cp\u003e11 (20.0)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.29032258064516%\"\u003e\n \u003cp\u003e39 (70.9)\u003csup\u003e\u0026nbsp;a\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.193548387096776%\"\u003e\n \u003cp\u003e5 (9.1)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.677419354838708%\"\u003e\n \u003cp\u003e\u003cstrong\u003eSBP (mmHg)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.838709677419356%\"\u003e\n \u003cp\u003e133 (120-142)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.29032258064516%\"\u003e\n \u003cp\u003e130 (121-147)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.193548387096776%\"\u003e\n \u003cp\u003e129 (121-147)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.677419354838708%\"\u003e\n \u003cp\u003e\u003cstrong\u003eDBP (mmHg)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.838709677419356%\"\u003e\n \u003cp\u003e85 (72-100)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.29032258064516%\"\u003e\n \u003cp\u003e80(75-90)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.193548387096776%\"\u003e\n \u003cp\u003e81 (77-88)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.677419354838708%\"\u003e\n \u003cp\u003e\u003cstrong\u003eGlucose (mg/dL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.838709677419356%\"\u003e\n \u003cp\u003e97 (86-118)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.29032258064516%\"\u003e\n \u003cp\u003e96.5 (88-112)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.193548387096776%\"\u003e\n \u003cp\u003e94 (91-104)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.677419354838708%\"\u003e\n \u003cp\u003e\u003cstrong\u003eCreatinine (mg/dL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.838709677419356%\"\u003e\n \u003cp\u003e1.15 (1-2)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.29032258064516%\"\u003e\n \u003cp\u003e0.9 (1-1)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.193548387096776%\"\u003e\n \u003cp\u003e0.9 (1-1)\u003csup\u003ea.b\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.677419354838708%\"\u003e\n \u003cp\u003e\u003cstrong\u003eeGFR (ml/dk/1.73m\u003csup\u003e2\u003c/sup\u003e)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.838709677419356%\"\u003e\n \u003cp\u003e67 (42-112)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.29032258064516%\"\u003e\n \u003cp\u003e91 (57-114)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.193548387096776%\"\u003e\n \u003cp\u003e91 (41-107)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.677419354838708%\"\u003e\n \u003cp\u003e\u003cstrong\u003eAlbumin (gr/dL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.838709677419356%\"\u003e\n \u003cp\u003e3.7 (2-4)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.29032258064516%\"\u003e\n \u003cp\u003e3.8 (3-4)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.193548387096776%\"\u003e\n \u003cp\u003e1.6 (1-2)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.677419354838708%\"\u003e\n \u003cp\u003e\u003cstrong\u003e24-hour proteinuria (gr)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.838709677419356%\"\u003e\n \u003cp\u003e6.6 (3-9)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.29032258064516%\"\u003e\n \u003cp\u003e3.5 (2-4)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.193548387096776%\"\u003e\n \u003cp\u003e9.1 (4-11)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.677419354838708%\"\u003e\n \u003cp\u003e\u003cstrong\u003eSerum C3 (mg/dL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.838709677419356%\"\u003e\n \u003cp\u003e122 (100-142)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.29032258064516%\"\u003e\n \u003cp\u003e122 (101-145)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.193548387096776%\"\u003e\n \u003cp\u003e140 (125-181)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.677419354838708%\"\u003e\n \u003cp\u003e\u003cstrong\u003eSerum C4 (mg/dL)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.838709677419356%\"\u003e\n \u003cp\u003e31 (27-43)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.29032258064516%\"\u003e\n \u003cp\u003e28 (21-33)\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.193548387096776%\"\u003e\n \u003cp\u003e45 (35-49)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"29.677419354838708%\"\u003e\n \u003cp\u003e\u003cstrong\u003eHematuria, n(%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.838709677419356%\"\u003e\n \u003cp\u003e13 (56.5)\u003csup\u003ea,b\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"21.29032258064516%\"\u003e\n \u003cp\u003e31 (39.7)\u003csup\u003e\u0026nbsp;b\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.193548387096776%\"\u003e\n \u003cp\u003e11 (84.6)\u003csup\u003e\u0026nbsp;a\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eAbbreviations:\u003c/strong\u003e Values in the same row not sharing the same superscript are significantly different at p\u0026lt;0.05 \u003cstrong\u003eeGFR:\u003c/strong\u003e estimating Glomerular filtration rate, \u003cstrong\u003eC:\u003c/strong\u003e Complement, \u003cstrong\u003eSBP:\u003c/strong\u003e systolic blood pressure, \u003cstrong\u003eDBP:\u0026nbsp;\u003c/strong\u003ediastolic blood pressure\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2:\u003c/strong\u003e Pathological features of the groups with LM and DIF\u003c/p\u003e\n\u003ctable border=\"1\" cellpadding=\"0\" cellspacing=\"0\" width=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"42.33378561736771%\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.111261872455902%\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroup 1 (n:23)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"14.111261872455902%\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroup 2 (n:78)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"15.332428765264586%\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroup 3\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(n:13)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"42.33378561736771%\"\u003e\n \u003cp\u003e\u003cstrong\u003eNumber of glomeruli* (median)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e9(5-14)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e8(6-12)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.332428765264586%\"\u003e\n \u003cp\u003e10(10-15)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" width=\"42.33378561736771%\"\u003e\n \u003cp\u003e\u003cstrong\u003eSegmental sclerosis, n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e17 (73.9)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e15 (19.2)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.332428765264586%\"\u003e\n \u003cp\u003e0(0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e6 (26.1)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e63 (80.8)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e13(100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" width=\"42.33378561736771%\"\u003e\n \u003cp\u003e\u003cstrong\u003eGlobal sclerosis, n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e17 (73.9)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e39(50.0) \u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.332428765264586%\"\u003e\n \u003cp\u003e3 (23.1)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e6 (26.1)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e39(50.0)\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e10 (76.9)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" width=\"42.33378561736771%\"\u003e\n \u003cp\u003e\u003cstrong\u003eBowman\u0026apos;s capsule adhesions, n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e14 (60.9)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e18 (23.1)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.332428765264586%\"\u003e\n \u003cp\u003e1 (7.7)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e9 (39.1)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e60 (76.9)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e12 (92.3)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" width=\"42.33378561736771%\"\u003e\n \u003cp\u003e\u003cstrong\u003eEDD in the mesangium, n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e10 (43.5)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e30 (38.5)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.332428765264586%\"\u003e\n \u003cp\u003e3 (23.1)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e13 (56.5)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e48 (61.5)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e10 (76.9)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" width=\"42.33378561736771%\"\u003e\n \u003cp\u003e\u003cstrong\u003eGlomerular hypertrophy, n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e13 (56.5)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e34 (43.6)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.332428765264586%\"\u003e\n \u003cp\u003e1 (7.7)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e10 (43.5)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e44 (56.4)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e12 (92.3)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"4\" width=\"42.33378561736771%\"\u003e\n \u003cp\u003e\u003cstrong\u003eInterstitial fibrosis, n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e10 (43.5)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e44 (56.4)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.332428765264586%\"\u003e\n \u003cp\u003e13(100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003eMild\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e10 (43.5)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e31 (39.7)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e0(0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003eModerate\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e3 (13.0)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e3 (3.8)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e0(0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003eSevere\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e0(0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e0(0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e0(0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" width=\"42.33378561736771%\"\u003e\n \u003cp\u003e\u003cstrong\u003eTubular atrophy, n(%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003eYes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e12 (52.2)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e28 (35.9)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.332428765264586%\"\u003e\n \u003cp\u003e0(0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e11 (47.8)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e50 (64.1)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e13(100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"4\" width=\"42.33378561736771%\"\u003e\n \u003cp\u003e\u003cstrong\u003eIg M, n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e+\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e11 (47.8)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e11 (14.1)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.332428765264586%\"\u003e\n \u003cp\u003e4 (30.8)\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e++\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e5 (21.7)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e6 (7.7)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e0(0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e+++\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e0(0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e0(0)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e0(0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e7 (30.4)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e61 (78.2)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e9 (69.2)\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"4\" width=\"42.33378561736771%\"\u003e\n \u003cp\u003e\u003cstrong\u003eC3, n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e+\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e5 (21.7)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e4 (5.1)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.332428765264586%\"\u003e\n \u003cp\u003e1 (7.7)\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e++\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e8 (34.8)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e7 (9.0)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e2 (15.4)\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e+++\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e1 (4.3)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e1 (1.3)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e0(0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003eNo\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e9 (39.1)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e66 (84.6)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e10 (76.9)\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" width=\"42.33378561736771%\"\u003e\n \u003cp\u003e\u003cstrong\u003eWT1, n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003eStaining P\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e14 (60.9)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e57 (73.1)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.332428765264586%\"\u003e\n \u003cp\u003e11 (84.6)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003eStaining loss\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e9 (39.1)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e21 (26.9)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e2 (15.4)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" width=\"42.33378561736771%\"\u003e\n \u003cp\u003e\u003cstrong\u003eNephrin, n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003eStaining P\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e3 (13.0)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e38 (48.7)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.332428765264586%\"\u003e\n \u003cp\u003e9 (69.2)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003eStaining loss\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e20 (87.0)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e40 (51.3)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e4 (30.8)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"4\" width=\"42.33378561736771%\"\u003e\n \u003cp\u003e\u003cstrong\u003eC4d, n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003eStaining P\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e17 (73.9)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e25 (32)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.332428765264586%\"\u003e\n \u003cp\u003e2(15.4)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; FSS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e13 (56)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e14 (17.9)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e0(0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e\u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; MS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e4 (17.3)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e11 (14.1)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e2 (15.4)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003eStaining N\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e6 (26.1)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"24.470588235294116%\"\u003e\n \u003cp\u003e53 (67.9)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"26.58823529411765%\"\u003e\n \u003cp\u003e11 (84.6)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" width=\"42.33378561736771%\"\u003e\n \u003cp\u003e\u003cstrong\u003eCoexistence staining pattern, n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003eCoNsLo-C4dP\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e16 (69.6)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"14.111261872455902%\"\u003e\n \u003cp\u003e26 (33)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"15.332428765264586%\"\u003e\n \u003cp\u003e0 (0)\u003csup\u003eab\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"24.470588235294116%\"\u003e\n \u003cp\u003eCoNsP-C4dN\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.470588235294116%\"\u003e\n \u003cp\u003e2 (9)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"24.470588235294116%\"\u003e\n \u003cp\u003e27 (35)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"26.58823529411765%\"\u003e\n \u003cp\u003e7 (54)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eNote:\u003c/strong\u003e Values in the same row not sharing the same superscript are significantly different at p\u0026lt;0.05\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAbbreviations: LM,\u0026nbsp;\u003c/strong\u003eLight microscopy; \u003cstrong\u003eDIF,\u003c/strong\u003e direct immunofluorescence; \u003cstrong\u003eGBM:\u003c/strong\u003e glomerular basement membrane, \u003cstrong\u003eWT1,\u003c/strong\u003e Wilms tumor1, \u003cstrong\u003eC3,\u003c/strong\u003e Complement 3; \u003cstrong\u003eIg M,\u003c/strong\u003e Immunoglobulin M; \u003cstrong\u003eEDD,\u003c/strong\u003e electron-dense deposits; \u003cstrong\u003eStaining P,\u003c/strong\u003e staining positivity; \u003cstrong\u003eStaining N,\u003c/strong\u003e staining negativity; \u003cstrong\u003eFSS,\u003c/strong\u003e Focal segmental staining; \u003cstrong\u003eMS,\u003c/strong\u003e Mesangial staining; \u003cstrong\u003eCoNsLo-C4dP,\u003c/strong\u003e coexistence of nephrin staining loss and C4d positivity; \u003cstrong\u003eCoNsP-C4dN,\u003c/strong\u003e coexistence of nephrin staining positivity and C4d negativity\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3.\u003c/strong\u003e Histologically findings of groups with EM\u003c/p\u003e\n\u003ctable border=\"1\" cellpadding=\"0\" cellspacing=\"0\" width=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"60.52287581699346%\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.143790849673203%\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"11.11111111111111%\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroup 1\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"11.11111111111111%\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroup 2\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"11.11111111111111%\"\u003e\n \u003cp\u003e\u003cstrong\u003eGroup 3\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" width=\"60.52287581699346%\"\u003e\n \u003cp\u003e\u003cstrong\u003ePodocyte foot process effacement \u0026gt;%70, n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.143790849673203%\"\u003e\n \u003cp\u003eyes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"11.11111111111111%\"\u003e\n \u003cp\u003e10 (43.5)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"11.11111111111111%\"\u003e\n \u003cp\u003e26 (33.3)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"11.11111111111111%\"\u003e\n \u003cp\u003e13(100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"15.562913907284768%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"28.14569536423841%\"\u003e\n \u003cp\u003e13 (56.5)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"28.14569536423841%\"\u003e\n \u003cp\u003e52 (66.7)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"28.14569536423841%\"\u003e\n \u003cp\u003e0(0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" width=\"60.52287581699346%\"\u003e\n \u003cp\u003e\u003cstrong\u003eWrinkling and thickening of GBM, n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.143790849673203%\"\u003e\n \u003cp\u003eyes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"11.11111111111111%\"\u003e\n \u003cp\u003e8 (34.8)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"11.11111111111111%\"\u003e\n \u003cp\u003e5 (6.4)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"11.11111111111111%\"\u003e\n \u003cp\u003e2 (15.4)\u003csup\u003ea.b\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"15.562913907284768%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"28.14569536423841%\"\u003e\n \u003cp\u003e15 (65.2)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"28.14569536423841%\"\u003e\n \u003cp\u003e73 (93.6)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"28.14569536423841%\"\u003e\n \u003cp\u003e11 (84.6)\u003csup\u003ea.b\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" width=\"60.52287581699346%\"\u003e\n \u003cp\u003e\u003cstrong\u003eIncreased mesangial matrix and mesangial cells in the glomeruli\u003c/strong\u003e\u003cstrong\u003e, n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.143790849673203%\"\u003e\n \u003cp\u003eyes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"11.11111111111111%\"\u003e\n \u003cp\u003e20 (87.0)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"11.11111111111111%\"\u003e\n \u003cp\u003e55 (70.5)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"11.11111111111111%\"\u003e\n \u003cp\u003e4 (30.8)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"15.562913907284768%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"28.14569536423841%\"\u003e\n \u003cp\u003e3 (13.0)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"28.14569536423841%\"\u003e\n \u003cp\u003e23 (29.5)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"28.14569536423841%\"\u003e\n \u003cp\u003e9 (69.2)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" width=\"60.52287581699346%\"\u003e\n \u003cp\u003e\u003cstrong\u003ePodocyte foot process focal detachments from the GBM, n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.143790849673203%\"\u003e\n \u003cp\u003eyes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"11.11111111111111%\"\u003e\n \u003cp\u003e18 (78.3)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"11.11111111111111%\"\u003e\n \u003cp\u003e49 (62.8)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"11.11111111111111%\"\u003e\n \u003cp\u003e2 (15.4)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"15.562913907284768%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"28.14569536423841%\"\u003e\n \u003cp\u003e5 (21.7)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"28.14569536423841%\"\u003e\n \u003cp\u003e29 (37.2)\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"28.14569536423841%\"\u003e\n \u003cp\u003e11 (84.6)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd rowspan=\"2\" width=\"60.52287581699346%\"\u003e\n \u003cp\u003e\u003cstrong\u003eGlomerular lipid droplet accumulation, n (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"6.143790849673203%\"\u003e\n \u003cp\u003eyes\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"11.11111111111111%\"\u003e\n \u003cp\u003e4 (17.4)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"11.11111111111111%\"\u003e\n \u003cp\u003e16 (20.5)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"11.11111111111111%\"\u003e\n \u003cp\u003e0(0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" width=\"15.562913907284768%\"\u003e\n \u003cp\u003eno\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"28.14569536423841%\"\u003e\n \u003cp\u003e19 (82.6)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"28.14569536423841%\"\u003e\n \u003cp\u003e62 (79.5)\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" width=\"28.14569536423841%\"\u003e\n \u003cp\u003e13(100.0)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eNote:\u003c/strong\u003e Values in the same row not sharing the same superscript are significantly different at p\u0026lt;0.05\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAbbreviations: EM,\u003c/strong\u003e Electron microscopy; \u003cstrong\u003eGBM,\u0026nbsp;\u003c/strong\u003eglomerular basement membrane\u0026nbsp;\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"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":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"C4d, nephrin, WT1, focal segmental glomerulosclerosis","lastPublishedDoi":"10.21203/rs.3.rs-1796559/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-1796559/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eBackground: \u003c/strong\u003eDifferential diagnosis between minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS) is important because prognosis and treatment response of each disease is different. However, in some cases these two diseases cannot be distinguished from each other clinically and histopathologically.\u003c/p\u003e\u003cp\u003eThe aim of this study is to determine whether glomerular complement 4d (C4d), nephrin, Renal Wilms' tumor-1 (WT1) staining can be used to differentiate FSGS and MCD.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eMethod: \u003c/strong\u003ePatients with primary FSGS and MCD were included in the study. Specificity and sensitivity of C4d, nephrin, WT-1 staining was calculated for the diagnosis of FSGS and MCD.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eResults: \u003c/strong\u003eGlomerular focal segmental C4d positivity (C4dP) was higher in FSGS compared to MCD patients. Nephrin staining positivity (NsP) was higher in MCD than FSGS patients (p\u0026lt;0.05). Specificity and sensitivity of glomerular C4dP for FSGS diagnose (85% and 73.9%) was higher compared to MCD (26.1% and 15.4%). Specificity and sensitivity of nephrin staining loss (NsLo) for FSGS diagnose (87% and 69%) was higher than MCD (30.8% and 13%). Specificity and sensitivity of coexistence of NsLo and C4dP (CoNsLo-C4dP) was higher in FSGS patients. Specificity and sensitivity of coexistence of NsP and C4d negativity (CoNsP-C4dN) was higher in MCD patients (100% and 77.8%). WT-1 was found neither specific nor sensitive for the differential diagnosis of FSGS and MCD.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eConclusion: \u003c/strong\u003eGlomerular C4dP and NsLo may be a method with high specificity and sensitivity in differentiating FSGS from MCD. CoNsLo-C4dP has the highest specificity and sensitivity for FSGS and CoNsP-C4dN for MCD.\u003c/p\u003e","manuscriptTitle":"Is the C4d, nephrin, and Wilms' tumor-1 staining pattern sensitive and specific for the differential diagnosis of focal segmental glomerulosclerosis and minimal change disease cases?","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2022-07-21 16:21:44","doi":"10.21203/rs.3.rs-1796559/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"04b3c2e6-e689-4bae-9061-f8e7bf2426f5","owner":[],"postedDate":"July 21st, 2022","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2022-08-19T13:14:30+00:00","versionOfRecord":[],"versionCreatedAt":"2022-07-21 16:21:44","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-1796559","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-1796559","identity":"rs-1796559","version":["v1"]},"buildId":"rHA-KDH7Qsr4HCuvH75dn","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}