Clinical utility of urinary neutrophil gelatinase-associated lipocalin and serum cystatin C in a cohort of liver cirrhosis patients with renal dysfunction: a challenge in the diagnosis of hepatorenal syndrome

Objectives This study aimed to assess urinary neutrophil gelatinase-associated lipocalin (uNGAL) and serum cystatin C (sCys C) in liver cirrhosis patients with renal dysfunction and to evaluate their role in the diagnosis of the hepatorenal syndrome (HRS). Patients and methods Forty-five liver cirrhosis patients were enrolled in the study and they were divided into three groups; the first group included 15 patients with normal renal function, the second group included 15 patients with HRS; and the third group included 15 patients with chronic kidney disease (CKD). There was a fourth group, which included 15 healthy controls. Liver and renal function tests, as well as the estimated glomerular filtration rate were determined. uNGAL was measured using the enzyme-linked immunosorbent assay, and the uNGAL/urinary creatinine concentration (UCC) ratio was calculated. sCys C was measured using the particle-enhanced immunoturbidimetric assay. Results The ratios of uNGAL and uNGAL/UCC were the highest among HRS patients. The combined uNGAL/UCC ratio and sCys C improved the sensitivity of diagnosis to 93.33% and specificity to 76.67%, with the highest area under the curve of 0.944, 95% confidence interval of 0.879-1.0 (P<0.001). The three biomarkers could successfully identify HRS at the following cutoffs: 84.94 ng/ml, 0.6 ng/mg, and 1.6 mg/l, respectively. Significant positive correlations were found between uNGAL, uNGAL/UCC ratios as well as sCys C and KDIGO stage in liver cirrhosis patients with CKD. Conclusion uNGAL and a better uNGAL/UCC ratio can be used alone or together with serum cystatin C as early biomarkers for HRS among patients with decompensated liver cirrhosis. Moreover, uNGAL, uNGAL/UCC as well as serum cystatin C could aid the prognostic assessment of cirrhotic patients with CKD.