Diagnostic accuracy of aspartate aminotransferase to platelet ratio index and fibrosis 4 scores in predicting advanced liver fibrosis in patients with end-stage renal disease and chronic viral hepatitis: Experience from Pakistan

The aim was to assess the diagnostic accuracy of APRI and FIB-4 in assessing the stage of liver fibrosis in end stage renal disease (ESRD) patients with chronic viral hepatitis and to compare the two tests with standard tru-cut liver biopsy. The study was conducted at Sindh Institute of Urology and Transplantation Karachi (SIUT) from May 2010 to May 2014. All ESRD patients, being considered as candidates for renal transplantation and in whom liver biopsy was performed were included. Fibrosis stage was assessed on liver biopsy using Ishak scoring system. The serum transaminases and platelet counts were used to calculate APRI and FIB-4 scores. Out of 109 patients, hepatitis C and B virus infections were present in 104 (95.4%) and 3(2.8%), respectively, while 2 (1.8%) patients had both infections. The mean Ishak fibrosis score was 1.95 ± 2. Advanced fibrosis was noted in 37 (34%) patients. Univariate analysis showed that advanced liver fibrosis was associated with lower platelets counts (P=0.001) and higher aspartate aminotransferase (AST) (P=0.001), alanine aminotransferase (ALT) (P=0.022), APRI score (P=0.001) and FIB-4 score (P=0.001). On logistic regression analysis, only APRI score (P < 0.001) was found to be the independent variable associated with advanced liver fibrosis. APRI score cutoff ≥1 indicating advanced fibrosis showed sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of 91.9%, 90.3%, 82.9%, 95.6%, respectively with area under the curve (AUC) of 0.97. Similarly, a FIB-4 score cutoff ≥1.1 had sensitivity, specificity, PPV and NPV of 70.27%, 66.67%, 52% and 81.36%, respectively with AUC of 0.74. APRI is more accurate noninvasive test for assessing advanced liver fibrosis in ESRD patients as compared to FIB-4. It can be used to obviate the need for liver biopsy in this high risk population.