Characterization of antibodies against core, NS3, NS4, NS5 region of hepatitis C virus in patients with hepatitis C

Third-generation screening assays for HCV antibodies were recently developed, in which a mixture of recombinant antigens from four different regions of the viral protein (core, NS3, NS4, NS5) was used. We reported the analytical performance and clinical usefulness of a third-generation counting immunoassay (RANREAM HCV) with PAMIA 30 (Toa Medical Electronics Inc., Kobe). In the present study, we investigated a modified assay of RANREAM HCV to detect region-specific antibody by using single antigen from four different regions, and studied response pattern of HCV antibodies and region-specific antibody in the patients with HCV infection. HCV antibodies of the seroconversion panel serum samples (BBI, USA) measured by RANREAM HCV were greatly coincident with those obtained by Ortho RIBA 3.0. The region-specific assay of serial sera from the patient with acute hepatitis revealed that anti-core antibody was produced at the initial stage of infection. In 165 patients with chronic hepatitis, pattern of region-specific antibody was different from case to case, although anti-NS3 and anti-core antibodies seemed to be predominant. The change of pattern was not observed for at least one year. All 2 cases who achieved complete remission with interferon showed low serum titer of anti-core antibody, in contrast to partial or non remission patients in which the level of anti-core antibodies was low in 6 of 16 cases.