Diagnostic Accuracy of Noninvasive Tests to Detect Advanced Hepatic Fibrosis in Patients With Hepatitis C and End-Stage Renal Disease

Abstract

For patients with liver disease from hepatitis C virus (HCV) infection complicated by end-stage renal disease (ESRD), it is important to assess liver fibrosis before kidney transplantation. We evaluated the accuracy of non-invasive tests to identify advanced hepatic fibrosis in patients with HCV and ESRD. In a retrospective study, we collected data on ratio of aspartate aminotransferase:alanine aminotransferase (AST:ALT), AST platelet ratio index (APRI), FIB-4 score, fibrosis index score, and King's score from 139 patients with ESRD and HCV infection (mean age, 52.8 y; 76.3% male; 86.4% African American; 45.3% with increased level of ALT). Results were compared with findings from histologic analyses of biopsies (reference standard). The primary outcome was detection of advanced fibrosis, defined as either bridging fibrosis or cirrhosis. Area under the receiver operating characteristic (AUROC) curves were constructed and optimal cutoff values were determined for each test. Sensitivity, specificity, positive and negative predictive values, and diagnostic accuracy were calculated. We repeated the analysis with stratification for normal levels of ALT (≤ 35 U/L for men and ≤ 25 u/L for women) and increased levels of ALT. FIB-4 scores identified patients with advanced fibrosis with an AUROC of 0.71 (95% CI, 0.61-0.80), the King's score with an AUROC of 0.69 (95% CI, 0.58-0.80), and the APRI with and AUROC of 0.68 (95% CI, 0.59-0.79). The accuracy of these tests increased when they were used to analyze patients with increased levels of ALT. All tests produced inaccurate results when they were used to assess patients with normal levels of AST and ALT. In patients with ESRD and HCV infection, FIB-4 scores, King's scores, and the APRI identify those with advanced fibrosis with AUROC values ranging from 0.68-0.71. Accuracy increased modestly when patients with increased levels of ALT were tested, but the tests produced inaccurate results for patients with a normal level of ALT.