Urine Neutrophil Gelatinase-associated Lipocalin as a Prognostic Biomarker in the first episode of Idiopathic Nephrotic Syndrome in children

INTRODUCTION: Idiopathic nephrotic syndrome (NS) is the most common glomerular disorder of childhood. The prognosis is correlated with treatment responsiveness and not renal histopathology. Most of the children experience multiple relapses and there is a risk of long-term drug dependence with possible side effects. Hence there is always a need for markers to assess the long-term outcome even in steroid responders. Urine neutrophil gelatinase-associated lipocalin (u NGAL) is an early risk marker of acute kidney injury and also a marker of progression of chronic kidney disease. Our aim was to determine if urine NGAL could predict steroid responsiveness at the onset which will help in planning and monitoring of treatment in idiopathic nephrotic syndrome
METHODS: A prospective observational study was conducted in children diagnosed with the first episode of idiopathic nephrotic syndrome in a tertiary care teaching hospital from January 2019 to July 2020. Urinary NGAL was done before starting steroids.
RESULTS: Seventy-nine children satisfying the inclusion criteria were included in the study. The mean age was 7.18(±2.86) years. The male: female ratio was 1.25: 1. All 63 children who had urine NGAL less than 10ng/ml responded to the standard dose of steroids at 8 weeks and attained remission. Out of the 16 children with NGAL > 10 ng/ml, 56.3%(n=9) responded to steroids by 8 weeks (intermediate and late steroid responders) and 43.8% (n= 7) were steroid resistant nephrotic syndrome (SRNS). Urine NGAL below 10 ng/ml was associated with steroid responsiveness in the first episode of nephrotic syndrome at 3 months (P value < 0.001).
DISCUSSION AND CONCLUSION: Urine NGAL below 10 ng/ml is an early predictive biomarker of steroid responsiveness in the first episode of idiopathic nephrotic syndrome.