Utility of Urinary Biomarkers Neutrophil Gelatinase-Associated Lipocalin and Kidney Injury Molecule-1 in Predicting Renal Scarring Compared with DMSA Scan in Children with Vesicoureteral Reflux

A BSTRACT Aim: To explore the utility of urinary biomarkers neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury molecule-1 (KIM-1) to assess the presence of renal scars in children with vesicoureteral reflux (VUR). Methodology: Prospective study of 18 months with children up to 12 years diagnosed with primary VUR or VUR secondary to posterior urethral valves. Convenience sampling yielded 25 consecutive VUR cases and 25 age- and sex-matched controls. All VUR cases underwent voiding cystourethrography for grading. Renal parenchymal scarring was diagnosed by 99mTc-DMSA scintigraphy and graded. Urinary NGAL and KIM-1 were measured by ELISA kits and normalized to urinary creatinine. Data were analyzed using SPSS version 25. Results: About 52% of VUR patients had renal scars on DMSA. The cohort had male predominance (88%). Urinary NGAL and KIM-1 were significantly higher in cases than controls and markedly elevated in scarred versus nonscarred kidneys. High-grade VUR was associated with significantly higher NGAL and KIM-1 values and their creatinine-normalized ratios than low-grade disease. In unilateral VUR, urinary NGAL and NGAL/urinary creatinine (NGAL/Ur. Cr) and in bilateral VUR, all biomarkers were significantly elevated in scarred kidneys. Receiver operating characteristic analysis demonstrated promising diagnostic performance for urinary NGAL and NGAL/Ur. Cr, with high sensitivity and specificity; urinary KIM-1 and KIM-1/Ur. Cr showed moderate diagnostic accuracy. Conclusion: Urinary NGAL and KIM-1 were elevated in children with VUR and renal scarring, with urinary NGAL and NGAL/Ur. Cr demonstrating promising diagnostic performance for detecting scars and are promising noninvasive adjuncts to imaging for identifying renal parenchymal damage in VUR.