Urinary liver-type fatty acid binding protein as a prognostic marker in sepsis-associated acute kidney injury in children: A single-center prospective observational study

Background: Sepsis-associated acute kidney injury (SA-AKI) in critically ill children is associated with significant morbidity and mortality. Urinary liver-type fatty acid binding protein (L-FABP) is a new biomarker studied in the critically ill population with sepsis. This study aimed to evaluate urinary L-FABP levels in children with septic shock and determine their utility in predicting SA-AKI and mortality. Subjects and Methods: This prospective observational study was conducted in children aged 1 month to 18 years admitted to the pediatric intensive care unit (PICU) with septic shock over a duration of 8 months. Relevant clinical details, including daily serum creatinine, were recorded. Urine for the L-FABP assay was collected within 4 h of admission and at 48 h. Results: Of 650 children admitted to PICU, 47 children with septic shock were included in the study. Overall incidence of SA-AKI was 53.2% (25/47). Median L-FABP in SA-AKI was 39.42 (interquartile range [IQR] 7.64–190.35) at admission and 24.05 (4.5–114.05) at 48 h. By receiver operating characteristic analysis, the area under the curve of urinary L-FABP level >50 ng/dL in predicting SA-AKI at admission was 0.79 (95% confidence interval: 0.61, 0.98) with a sensitivity of 60.1% and specificity of 75% ( P = 0.024). Urinary L-FABP (Median [IQR]) was higher in nonsurvivors (119.08 [11.50–412.76]) compared to survivors (21.87 [4.05–101.24], P = 0.04). Conclusions: Elevated urinary L-FABP levels can be a promising biomarker for early prediction of kidney injury and mortality in septic shock, warranting validation in larger studies.