A Cross-Sectional Study of Urinary Neutrophil Gelatinase-Associated Lipocalin and its Association with Steroid Responsiveness in Iraqi Children with Idiopathic Nephrotic Syndrome

Background: Steroid-resistant nephrotic syndrome (SRNS)is associated with serious complications and financial burdens. Studies reported increased urinary neutrophil gelatinase-associated lipocalin (uNGAL) levels in children with idiopathic nephrotic syndrome (INS). Objectives: This study aimed to evaluate the uNGAL potential to distinguish SRNS from steroid-sensitive nephrotic syndrome (SSNS) in Iraqi children. Patients and Methods: Children with SRNS (n=31) and SSNS (n=32) were recruited from Babylon Hospital for Maternity and Pediatrics from March to June 2022. Patients' data included demographics, clinical characteristics, and urinary lab tests. The uNGAL concentrations were measured via a commercially available ELISA kit. Results: A significantly higher uNGAL median (p-value<0.001) was noted in the SRNS group (median [IQR] = 131.512 [30.28] ng/mL) than in the SSNS group (88.45 [41.6] ng/mL). The correlation between uNGAL levels and estimated glomerular filtration rate (eGFR) was negative (Spearman's rho coefficient = − 0.599, p<0.001). The discriminatory power ofuNGAL to discern SRNS from SSNS was significantly high (AUC=0.899, p<0.0001) with a sensitivity of 87.1% and specificity of 87.5% at an optimal cut-off value of 111.091 ng/mL. Conclusion: uNGAL is associated with a reliable discriminatory strength to distinguish, noninvasively, children with SRNS from those with SSNS. Received: Jan. 2023 Accepted: Jul, 2023 Published: Oct.2023