Urinary Neutrophil Gelatinase Associated lipocalin (NGAL) as A Biomarker of Acute Kidney Injury in Patients with Liver Cirrhosis

Background: The severity of acute kidney injury (AKI) syndrome varies. The blood urea nitrogen (BUN) and creatinine (Cr) retention, as well as a rapid drop in the glomerular filtration rate (GFR), are its defining features. The discovery of a superior gold standard to serum Cr concentration or urine output, as well as proof that a marker-directed therapy strategy may enhance clinical outcomes, would be significant step forward for AKI biomarker research.
Objective: To determine if urine neutrophil gelatinase associated lipocalin (uNGAL) is a reliable indicator of AKI in patients with liver cirrhosis.
Patients and methods: This study included 80 cirrhotic patients. Patients were allocated into two groups as follows: group I: 30 cirrhotic cases with normal kidney functions (without AKI) and group II: 50 cirrhotic cases with AKI who were divided into 3 subgroups according to type of AKI: group IIa included 20 cases with prerenal AKI, group IIb included 20 cases with hepatorenal syndrome (HRS-AKI) and group IIc included 10 cases with acute tubular necrosis (ATN).
Results: In terms of uNGAL, there were statistically significant variations across the groups that were examined (P value <0.001) with mean uNGAL value is highest in group IIc (ATN) (259.80±44.364 ng/ml) followed by group IIb (HRS-AKI) (192.85±40.782 ng/ml) than group IIa (Pre-renal AKI) (61.00±8.706 ng/ml) and group I (29.00±5.420 ng/ml). uNGAL at a cut-off value ≥239 ng/ml could differentiate ATN from HRS with sensitivity of 80%, 90% specificity, 80% PPV, 90% NPV, with an area under curve (AUC) = 0.880, and P value of ˂ 0.001. uNGAL at cut-off value >190 ng/ml had 100% sensitivity, 88.24% specificity, 60% PPV, and 100% NPV for predicting inhospital mortality in cirrhotic patients with AKI (AUC = 0.96; P ˂ 0.001).
Conclusion: To diagnose and differentiate between various causes of AKI in cases with liver cirrhosis, uNGAL may be employed as an accurate biomarker. Additionally, it has prognostic value in such patients.