Urine Liver-Type Fatty Acid Binding Protein; Biomarker for Diagnosing Acute Kidney Injury and Predicting Mortality in Cirrhotic Patients

Abstract

Objective: To determine impact of urine liver-type fatty acid binding protein (uL-FABP) and urine neutrophil gelatinase-associated lipocalin (uNGAL), which were biomarkers linked to acute kidney injury (AKI), in AKI diagnosis and prediction of 28-day mortality among hospitalized cirrhotic patients. Materials and Methods: We prospectively enrolled hospitalized cirrhotic patients at a tertiary care university hospital between June 2018 and November 2019. The uL-FABP, uNGAL, and plasma NGAL (pNGAL) were collected within 48 hours of admission. Cutoff values of biomarkers for diagnosing AKI derived from receiver operating characteristic (ROC) curve. Logistic regression analysis was used to identify independent factors for 28-day mortality. Results: We enrolled 109 cirrhotic patients in derivative cohort, 41.3% had AKI. Median uL-FABP, uNGAL, and pNGAL levels in AKI group were higher than non-AKI group: 8.1 vs. 2.8 ng/mL (p=0.002), 40.5 vs. 10.1 ng/mL (p<0.001), and 195.7 vs 81.4 ng/mL (p=0.001), respectively. Areas under the ROC curve of uL-FABP, uNGAL, and pNGAL for AKI diagnosis were 0.68, 0.73 and 0.68, respectively. Also, all biomarkers were significantly higher in mortality group. Multivariate analysis showed that the only independent predictor for 28-day mortality was uL-FABP ≥ 4.68 ng/mL (odd ratio 4.15, p=0.02). Conclusion: UL-FABP, uNGAL, and pNGAL are associated with AKI in hospitalized cirrhotic patients. Moreover, uL-FABP ≥ 4.68 ng/mL was a significant independent predictor for 28-day mortality.