Duration of HCV infection as a predictor of nonresponse to interferon.

Duration of hepatitis C virus (HCV) infection is a key feature in determining responsiveness to interferon (IFN). Studies assessing its value as a predictive factor in chronic HCV infection show that a long duration of infection reduces the likelihood of a sustained response to IFN (defined as ALT normalization and clearance of serum HCV-RNA). The effect of HCV infection duration is independent of the presence of cirrhosis and level of HCV viremia. Meta-analysis of IFN trials in acute HCV infection shows an obvious effect of the drug on long-term ALT normalization and HCV-RNA clearance. Treatment of HCV infection during the acute or early chronic phase could therefore maximize therapeutic effectiveness.