Urinary neutrophil gelatinase-associated lipocalin: a key biomarker for differentiating acute kidney injury and predicting short-term mortality in liver cirrhosis patients.

BACKGROUND

urinary neutrophil gelatinase-associated lipocalin (uNGAL) has emerged as a promising biomarker in clinical settings for the differential diagnosis of acute kidney injury (AKI) in chronic liver disease (CLD). This prospective study aims to evaluate the efficiency of uNGAL in the differential diagnosis of AKI among patients with CLD and in predicting short-term mortality in this population.

METHODS

This prospective observational study was conducted from September 2021 to March 2024 at Kasturba Medical College, Manipal, among patients with AKI and CLD. The study was initiated after obtaining institutional ethics committee approval. Demographic and clinical data, including urine samples for NGAL analysis, were collected. Patients were followed for 90 days to record clinical outcomes.

Results

Among the 188 CLD patients, 42.6% (N = 80) exhibited prerenal AKI, 41.5% (N = 78) were diagnosed with hepatorenal syndrome (HRS), and 16% (n = 30) were identified as having acute tubular necrosis (ATN). u-NGAL Cutoffs of 631 ng/ml distinguish HRS from ATN [AUC: 0.949, 95% C.I (0.895-1)], with a sensitivity of 92% and specificity of 93%, while 257 ng/ml and 236 ng/ml predict 30-day [AUC: 0.807, 95% C.I (0.740-0.875)] and 90-day [AUC: 0.809, 95% C.I (0.745-0.873)] mortality, respectively. Elevated alanine transaminase (ALT), Model for End-stage Liver Disease-sodium (MELD-Na), and uNGAL levels serve as independent predictors of mortality. Patients with uNGAL >236 ng/ml show higher 90-day mortality, underscoring uNGAL's diagnostic, and prognostic value in AKI.

CONCLUSION

This study shows that uNGAL distinguishes HRS from ATN and serves as a valuable predictor of 30-day and 90-day mortality. Additionally, higher levels of ALT, MELD-Na score, and uNGAL were identified as independent risk factors for mortality.