[How to measure liver fibrosis in viral hepatitis?]

During viral hepatitis, the evaluation of the fibrosis has, above-all, a prognostic value. The complications of the illness only appear after the onset of cirrhosis in the great majority of cases. Liver biopsy remains the gold standard but has intrinsic limits linked to its size and the heterogeneity of the lesions in the liver, and is extrinsically linked to inter-observer variability (quite insignificant for fibrosis when using the METAVIR classification). The biopsy causes very little morbidity and insignificant mortality, however it does necessitate hospitalisation. Among the isolated hepatic blood markers, the prothrombin level and the hyaluronic acid have good specificity but insufficient sensitivity for the diagnosis of severe fibrosis. Among the tests combining several markers, the FibroTest is the best studied and the best performing, at least in the case of hepatitis C. It must be interpreted with caution due to the possible variations of its different constituents not linked to hepatic fibrosis. Ultrasound has a good specificity but its sensitivity is insufficient for the diagnosis of cirrhosis. Elastography, a non-invasive percutaneous technique, is promising. The FibroTest must be used as first-line, notably in hepatitis C, however is not currently covered by the National Health Insurance (assurance-maladie). Apart from in therapeutic trials, the liver biopsy should only be proposed in the case of uncertainty about the degree of fibrosis and, above-all, the existence of cirrhosis, and only then when there are practical implications.