Mr-Proadrenomedullin As Biomarker Of Renal Damage In Urinary Tract Infection In Children

Abstract Background: Midregional-proadrenomedullin (MR-proADM) is a useful prognostic peptide in severe infectious pathologies in the adult population. However, there are no studies that analyze its utility in febrile urinary tract infection (fUTI) in children. An accurate biomarker would provide an early detection of patients with kidney damage, avoiding other invasive tests like renal scintigraphy scans. Our objective is to study the usefulness of MR-proADM as a biomarker of acute and chronic renal parenchymal damage in fUTI within the pediatric population. Material and Methods: A prospective cohort study was conducted in pediatric patients with fUTI between January 2015 and December 2018. Plasma and urine MR-proADM levels were measured at admission in addition to other laboratory parameters. After confirmation of fUTI, renal scintigraphy scans were performed during the acute and chronic stages. A descriptive study has been carried out and sensitivity, specificity and ROC curves for MR-proADM, C-reactive protein, and procalcitonin were calculated. Results: 62 pediatric patients (34 women) were enrolled. Scintigraphy showed acute pyelonephritis in 35 patients (56.5%). Of those patients, median of plasmatic MR-proADM (P-MR-proADM) showed no differences compared to patients without pyelonephritis. 7 patients (11.3%) developed renal scars (RS). Their median P-MR-proADM levels were 1.07 nmol/L (IQR 0.66 – 1.59), while in patients without RS were 0.48 nmol/L (0.43 – 0.63) (p<0.01). The AUC in this case was 0.92 (95% CI 0.77 – 0.99). We stablished an optimal cut-off point at 0.66 nmol/L with sensitivity 83.3% and specificity 81.8%. Conclusion: MR-ProADM has a poor ability to diagnose pyelonephritis in pediatric patients with fUTI. However, P-MR-proADM showed as a very reliable biomarker for RS prediction. Keywords: Proadrenomedullin, biomarker, urinary tract infection, pediatric, renal scarring