Urinary NGAL and Renalase as Non-Invasive Biomarkers for Detection of Deterioration of Kidney Function and Kidney Scarring in Children with Neurogenic Bladder

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 NB patients and 45 age- and gender-matched healthy children (reference group). Urinary NGAL and Renalase levels were measured using ELISA. NB patients 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 NB patients 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). NB patients 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 NB patients, 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.