Hepatitis C virus serotype II responds more favorably to interferon-alpha therapy

To determine whether serological typing of hepatitis C virus correlated with the response to interferon-alpha therapy, hepatitis C virus serotypes were determined by subtype-specific antibody to NS4 polypeptide by enzyme-linked immunosorbent assay in 55 Japanese patients with chronic active hepatitis C who subsequently received recombinant interferon-alpha 2a therapy. Response to interferon-alpha was defined as complete and sustained (n = 12), complete response followed by relapse (n = 26), and no response (n = 17). There was no difference in the clinical biochemical parameters between these patients groups. However, a higher proportion (50.0%) of patients with hepatitis C virus serotype II showed complete and sustained response to interferon-alpha, compared to serotype I (11.1%, p < 0.01). These data indicate that this simple hepatitis C virus serotyping assay is a useful predictor of response to interferon-alpha therapy in patients with chronic hepatitis C virus infection.