Low cell binding ability of HCV is closely related to interferon treatmentespecially in patients with HCV genotype 2a/2b - A large series prospective study on Japanese patients with chronic hepatitis C

Background/Aims: We have previously shown that the quantity of antibody-fre e virion in the pre-treatment sera of the patients with chronic hepatitis C is a good predictive factor for the efficacy of interferon treatment. Howe ver, the biological significance of the free virion should be verified by a prospective study. Methods: We prospectively evaluated 152 consecutive patients with chronic h epatitis C who received a standardized interferon treatment, and analyzed t he free virion and the binding titers, the ability of hepatitis C virus (HC V) to bind to the human lymphocytic cell line. Results: Sixty-five patients achieved a long-term sustained remission, 76 p atients did not respond to the interferon therapy, and 11 patients dropped out. The sera from the patients with genotype 2a/2b had significantly lower free virion and cell binding titers than those with genotype Ib. A multiva riate analysis showed three independent variables associated with the inter feron response; cell binding titer <10(0.5)/ml, viral load <10(4.5) copies/ 50 mul, and genotype 2a/2b with odds ratios of 14,6, 11,8, and 9,8, respect ively. Conclusions: The low level of in vitro cell binding ability of HCV helped t o clarify the good responsiveness to interferon observed in patients especi ally with a high viral load of genotype 2a/2b.