Utility of Urinary Biomarkers Neutrophil Gelatinase-Associated Lipocalin and Kidney Injury Molecule-1 as a Marker for Diagnosing the Presence of Renal Scar in Children with Vesicoureteral Reflux (VUR): A Cross-Sectional Study

Abstract

Aim: To explore the possibility of using urinary biomarkers neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) to assess the presence of renal scars in children with Vesicoureteric Reflux (VUR). Materials and Methods: This cross-sectional study was conducted in 94 children aged 0–16 years diagnosed with VUR in the Department of Pediatric Surgery, JIPMER. Urinary biomarkers were measured using the enzyme-linked immunosorbent assay kits, normalized with urinary creatinine (Cr) and compared with severity of VUR (low grade [I and II] and high grade [III, IV, and V]), presence or absence of renal scar in VUR patients and severity of renal scar. Independent Student's t-test, Mann–Whitney U-test, and analysis of variance Kruskal–Wallis test were used for comparison, and receiver operating characteristic (ROC) curve analysis for predicting the accuracy of biomarkers in detecting the presence of renal scars. Results: The median urinary NGAL (uNGAL) value was higher in children with renal scar (1.49 ng/mL) than those without renal scar (0.58 ng/mL) and was statistically significant (<0.001). Whereas median uNGAL/Cr was higher in children with renal scar (0.07) than those without renal scar (0.03) but was not statistically significant (P = 0.06). Urinary KIM-1 and urinary KIM-1/urinary Cr (uKIM-1/Cr) was not found to be a significant predictor of renal scar. The difference of uNGAL/Cr was comparable between the grades of renal scar but was not statistically significant. On ROC curve analysis, uNGAL had area under the ROC curve (AUC) of 0.769 with 71% of both specificity and sensitivity, whereas uNGAL/Cr was found to be a poor predictor of renal scar with AUC of 0.611, 60% sensitivity, and 61.2% specificity. Conclusion: uNGAL can serve as a noninvasive marker for diagnosing the presence of renal scar in children with VUR and a multicentric more extensive cohort study may be needed to strengthen or negate its role.