Antiviral effect of ribavirin in early non-responders to interferon monotherapy assessed by kinetics of hepatitis C virus RNA and hepatitis C virus core antigen.

BACKGROUND/AIMS: To evaluate the efficacy of ribavirin, given in second intention in non-responders to interferon alone, by studying viral kinetics.
METHODS: We conducted a trial including 203 patients with chronic hepatitis C, naïve of treatment. Patients were treated with interferon three times a week with or without ribavirin and amantadine according to response. Viral kinetics were assessed by serial measurements of HCV RNA (bDNA 3.0 and Monitor 2.0) and a new assay, trak-C, able to quantify total Hepatitis C virus (HCV) core antigen.
RESULTS: A significant initial drop in HCV RNA or HCV core antigen, under interferon alone, was associated with response to therapy, -4.85+/-1.33 log for HCV RNA in sustained responders versus -1.86+/-1.53 log for others groups, P<0.001. In patients receiving ribavirin in second intention, we also observed a similar drop in HCV RNA and HCV core antigen, predictive of sustained response, -2.67+/-1.26 log for HCV RNA in sustained responders versus -0.44+/-0.49 log in non-responders, P<0.001.
CONCLUSIONS: Ribavirin has probably an additional antiviral effect in interferon treated patients. Kinetics of HCV RNA and HCV core antigen under treatment are highly predictive of a sustained virological response.