High sustained response rate and clearance of viremia in chronic hepatitis C after treatment with interferon-alpha 2b for 60 weeks.

To evaluate the effect of prolonged interferon-alpha treatment on serum aminotransferase levels and hepatitis C virus RNA in serum, 40 patients with chronic hepatitis C virus infection were treated with 3 MU interferon-alpha 2b thrice weekly for 60 wk. Before treatment all patients had elevated serum ALT levels for at least 1 yr, antibodies to HCV by second-generation tests and liver histological findings consistent with chronic hepatitis C. Before treatment hepatitis C virus RNA was found in serum in 39 of 40 (97.5%) patients. Normalization of ALT levels at treatment cessation was seen in 24 of 40 (60%) patients, of whom 15 of 24 (62.5%) had sustained ALT responses up to 24 wk after treatment. At follow-up, 24 wk after treatment, hepatitis C virus RNA was cleared from serum in 17 of 40 (42.5%) patients, including all sustained responders, one nonsustained responder and one nonresponder. We conclude that 60 wk of treatment with interferon-alpha 2b seems to induce a high percentage of sustained response, which coincides with cessation of viral replication.