Urinary Neutrophil Gelatinase-Associated Lipocalin as Prognostic Biomarker in Pediatric Idiopathic Nephrotic Syndrome

Background: Idiopathic nephrotic syndrome (INS) is the most common childhood glomerular disorder. Neutrophil gelatinase-associated lipocalin (NGAL) has shown promising results in predicting steroid response in nephrotic patients. This study aims to determine urinary NGAL level sensitivity and specificity in children with INS, as a prognostic factor for predicting steroid response. Materials and Methods: In this case-control study, ۸۳ nephrotic children from one to fifteen years old were enrolled, from January ۲۰۲۱ to January ۲۰۲۲. Urine samples were collected in the first episode or relapse of nephrotic syndrome, prior to steroid or alternative treatments. NGAL level was measured by ELISA according to the manufacturer's instructions. Results: Of the ۸۳ patients, ۲۱ (۲۵.۶%) developed steroid resistance. According to the results of this study, a statistically significant relationship was observed between urinary NGAL level and corticosteroid resistance (p-value۰.۰۵), and the NGAL/Cr level with a cut-off point of ۱۳.۶, with a sensitivity of ۹۰.۴% and a specificity of ۷۳.۵% is in favor of corticosteroid resistance. Conclusion: The higher level of urinary NGAL/Cr is associated with the level of resistance to corticosteroids in nephrotic syndrome, and as its level increases, the probability of response to corticosteroids in this disease decreases.