Urinary NGAL and renalase as non-invasive biomarkers for detection of deterioration of kidney function and kidney scarring in children with neurogenic bladder.

Abstract

Background: Urinary biomarkers such as neutrophil gelatinase-associated lipocalin (NGAL) and renalase hold promise for assessing kidney health, yet their role in the pediatric neurogenic bladder (NB) remains unclear. This study evaluates their clinical utility in detecting kidney dysfunction and their association with disease severity.

Methods: A cross-sectional study included 44 patients with NB and 45 age- and gender-matched healthy children (reference group). Urinary NGAL and renalase levels were measured using ELISA. Patients with NB were categorized based on glomerular filtration rate (GFR) and kidney scarring. Biomarker levels were compared using the Mann-Whitney U test, and their correlations with functional parameters (DTPA, DMSA) were assessed using Spearman's correlation.

Results: Urinary NGAL and renalase levels were significantly higher in patients with NB than in the reference group (NGAL: 31.86 vs. 23.40 pg/mg creatinine, p = 0.0345; renalase: 2.75 vs. 1.76 ng/mg creatinine, p = 0.0493). Patients with NB with GFR < 60 mL/min/1.73 m² or kidney scarring had elevated NGAL (46.90 vs. 26.76 pg/mg creatinine, p = 0.0406) and renalase (3.76 vs. 1.82 ng/mg creatinine, p = 0.0050). Both biomarkers correlated inversely with GFR (NGAL: r = -0.3344, p = 0.0326; renalase: r = -0.4054, p = 0.0085) and increased with kidney scarring, suggesting their potential role in assessing kidney injury severity.

Conclusions: Urinary NGAL and renalase are elevated in pediatric patients with NB, particularly in those with kidney dysfunction, and correlate with GFR and kidney scarring. These findings highlight their potential as non-invasive markers for early detection and monitoring of kidney impairment in NB. Future longitudinal studies are warranted to validate their diagnostic and prognostic utility.