C) Liver biopsy examination:
The diagnosis and the prognosis of chronic viral hepatitis are based on histological examination of liver biopsy. Several interpretation scores have been proposed, the three most widely used being the Knodell's score, the Metavir score, and the Ishak's score (5, 6). There is a consensus that two parameters need to be measured in liver biopsies.
(i) Necro-Inflammatory activity, that reflects the degree of necrosis and inflammation in the liver. Necro-inflammatory activity is the main predictor of liver disease outcome. Indeed, the patients with a high activity score are at risk of rapid fibrosis progression and cirrhosis. The degree of necro-inflammatory activity is important in assessing whether or not treatment is indicated , especially in patients without ALT elevations or with relative contra-indications to IFN-a-based therapy.
(ii) Fibrosis. Fibrosis assessment also has prognostic significance, because it allows to differentiate : the patients with no or mild fibrosis, generally early disease or slow progressors; the patients with severe fibrosis, who have more advanced disease and are at higher risk of developing cirrhosis ; the patients with cirrhosis, , who are at high risk of complications and especially of developing hepatocellular carcinoma.