Detection of anti-HCV IgM antibodies in patients with chronic hepatitis C treated with interferon

Objective: To assess the role of IgM antibodies to hepatitis C virus core protein (anti-HCV IgM) as a marker of chronic HCV infection and as a predictor of successful interferon (IFN) treatment. Design: Anti-HCV IgM levels were evaluated at baseline, during IFN therapy and during a follow-up period. Methods: Anti-HCV IgM levels were evaluated in 62 patients (47 men and 15 women, aged 25-65 years) with biopsy-proven chronic active hepatitis C. Fifty-one of the patients received α-IFN 3 MU three times a week for 6 months and 11 received the same therapy for 12 months. Twenty patients showed a long-term response; fourteen responded but subsequently suffered a relapse; twenty-eight did not respond to the treatment. Follow-up in all patients lasted for at least 6 (mean ± SD9.8 ± 5.4, range 6-29) months after the end of the therapy. Results: Anti-HCV IgM were detected in 35 patients (56.4%) at baseline; no significant differences were observed between the three groups studied. Almost all members of the groups showing a relapse or no response remained positive at the end of therapy and follow-up. In contrast, we observed a progressive disappearance of anti-HCV IgM in patients responsive to interferon therapy over the long term. Conclusion: The loss of anti-HCV IgM positivity in patients positive at baseline can predict the long-term response to IFN therapy.