Predictive value of FIB-4 versus fibrotest, APRI, FIBROINDEX and FORNS to noninvasively estimate fibrosis in hepatitis C

Abstract

Reply: We thank Dr. Adler's group for their interesting results which confirm the accuracy of the FIB-4 index for delineating significant (requiring therapy) and nonsignificant fibrosis in chronic hepatitis C (HCV), in HCV monoinfection as well as in human immunodeficiency virus (HIV)-HCV coinfection.1 Adler et al. included in their analysis a broad population of patients, some of them with chronic hepatitis B (HBV) infection and alcoholic liver disease. Our results in chronic hepatitis B (work submitted) suggest that the FIB-4 index is robust to diagnose nil-to-moderate fibrosis, providing therefore an interesting first-line evaluation. The comparison of the FIB-4 index with liver biopsies performed the same day in 138 patients allowed the correct identification of patients with nil-to-moderate fibrosis (METAVIR F0-F2) with an area under the receiving operating characteristic curve of 0.81 (confidence interval 95% 0.74-0.88) (P < 0.001). Interestingly, the longer the length of the liver biopsy, the higher was the AUROC increasing from 0.81 to 0.91. The FIB-4 score was less accurate for assessing the diagnosis of severe fibrosis (METAVIR F3-F4). The high number of African patients included in our study could explain at least in part these results: most discordant patients with a high FIB-4 index and nil-to-moderate fibrosis had a low platelet count, possibly following chronic malarial infection. In alcohol-related liver disease (ALD), our analysis of the FIB-4 index in 160 patients is disappointing and confirmed the idea that existing diagnostic tests based on aminotransferase level and platelet count are not suitable for the determination of fibrosis stage in patients with ALD (work submitted). This point could receive several nonexclusive explanations: alcohol is well known to induce a higher AST/ALT ratio than other causes of liver diseases; the level of aminotransferases is classically lower in ALD and this has been related to pyridoxal phosphate deficiency; platelet count is affected by the acute toxicity of ethanol on thrombopoiesis and its correlation to portal hypertension is therefore poor in that context. All these alcohol-related variations clearly make an impact on the FIB-4 index which includes AST, ALT, GGT and the platelet count. The accuracy and the low cost of the FIB-4 index should make the FIB-4 index, with the fibroscan, a first line noninvasive biochemical marker and should be added to the recommendations of the Haute Autorité de Santé.2 Anais Vallet-Pichard M.D.*, Vincent Mallet M.D., Ph.D.*, Stanislas Pol M.D., Ph.D.*, * Université Paris Descartes; INSERM U.567; APHP, Hôpital Cochin, Unité d'hépatologie Paris, France.