Using vibration controlled transient elastography and FIB-4 to assess liver cirrhosis in a hepatitis C virus infected population

Abstract

We assessed the performance characteristics of the Fibrosis-4 (FIB-4) score in a veteran population with chronic hepatitis C virus (HCV) infection and used vibration controlled transient elastography (VCTE) as the gold standard.All VCTE studies were performed by a single operator on United States veterans with HCV infection presenting for care at the Atlanta VA Medical Center (AVAMC) over a 2 year period. VCTE liver stiffness measurements (LSM) were categorized as cirrhotic if LSM was >12.5 kPa and non-cirrhotic if LSM was ≤12.5 kPa. FIB-4 scores ≤3.25 were considered non-cirrhotic and scores >3.25 were considered cirrhotic. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were calculated for the FIB-4 score. A second analysis was done which identified and excluded indeterminate FIB-4 scores, defined as any value between 1.45 and 3.25.When FIB-4 was used to screen for liver cirrhosis using VCTE as the gold standard, sensitivity was 42%, specificity was 88%, PPV was 62%, and NPV was 76%. When indeterminate FIB-4 scores were excluded from the analysis, sensitivity was 95%, specificity was 61%, PPV was 62%, and NPV was 94.4%. In a veteran population with chronic HCV infection, we found the sensitivity of the FIB-4 score to be unacceptably low for ruling out liver cirrhosis when using a binary cutoff at 3.25. Using a second staging method like VCTE may be an effective way to screen for liver cirrhosis in persons with chronic HCV, especially when the FIB-4 score is in the indeterminate range.