Interferons in chronic viral hepatitis

Interferons represent the rapid defence system against viral infections. This review describes the types of interferon and their effects on chronic viral hepatitis. The role of interferon therapy for hepatitis B has been intensively evaluated over the last few years. Response rates of approximately 30% can be achieved by a 4- to 6-month course of alpha interferon treatment in non-immunosuppressed Caucasian patients. Assessment of interferon therapy for hepatitis C has had to rely on indirect markers of disease activity. Current data available indicate response rates in terms of aminotransferase activities of about 50% of patients treated. However, relapse after discontinuation of alpha interferon treatment is common. At present there is no valid treatment procedure for chronic hepatitis D infection. Only a minority of patients with chronic hepatitis D appears to benefit even transiently from alpha interferon.