FIB-4: an inexpensive and accurate marker of fibrosis in HCV infection. comparison with liver biopsy and fibrotest

Abstract

To optimize the management of patients with chronic hepatitis C virus (HCV) infection, noninvasive tests to determine the degree of hepatic fibrosis have been developed. The aims of this study were (1) to validate a simple, inexpensive, noninvasive test called FIB-4, which combines standard biochemical values (platelets, ALT, AST) and age, in a series of 847 liver biopsies performed in HCV-monoinfected patients; and (2) to compare the results of 780 FIB-4 and FibroTests performed the same day in a series of 592 HCV-infected patients. The FIB-4 index enabled the correct identification of patients with severe fibrosis (F3-F4) and cirrhosis with an area under the receiver operating characteristic curve of 0.85 (95% CI 0.82-0.89) and 0.91 (95% CI 0.86-0.93), respectively. An FIB-4 index <1.45 had a negative predictive value of 94.7% to exclude severe fibrosis with a sensitivity of 74.3%. An FIB-4 index higher than 3.25 had a positive predictive value to confirm the existence of a significant fibrosis (F3-F4) of 82.1% with a specificity of 98.2%. Using these ranges, 72.8% of the 847 liver biopsies were correctly classified. The FIB-4 index was strongly correlated to the FibroTest results for a score <1.45 or >3.25 (kappa = 0.561, P < 0.01). A FIB-4 value <1.45 or >3.25 (64.6% of the cases) was concordant with FibroTest results in 92.1% and 76%, respectively.

Conclusion: For values outside 1.45-3.25, the FIB-4 index is a simple, accurate, and inexpensive method for assessing liver fibrosis and proved to be concordant with FibroTest results.