CLINICAL-EVALUATION OF TITRATION OF HEPATITIS-C VIRUS CORE ANTIBODY AND ITS SUBCLASSES

Titrations of anti-hepatitis C core (anti-HCc) immunoglobulin G (IgG) antibodies and its subclasses were studied in 90 patients with acute a nd chronic hepatitis C virus (HCV) infection, including 27 patients wh o underwent interferon (IFN) therapy. The positivity rates for each an ti-HCc subclass were as follows: 95.2% for IgG1, 12.0% for IgG2, 69.9% for IgG3 and 19.3% for IgG4. The total anti-HCc IgG titre correlated well with the IgG1 titre, indicating that IgG1 was the main virus-spec ific IgG. Changes of IgG1 production mainly contributed to fluctuation s of the anti-HCc IgG titre and corresponded well to positivity for HC V-RNA during and after IFN therapy. IgG3 was detected prior to IgG1 du ring the early phase of acute hepatitis in some cases and also appeare d with relapse after IFN therapy. The serial assay of anti-HCc subclas ses showed the patients' humoral immune response to HCV infection, and might be useful for evaluation of anti-viral immunity influenced by I FN therapy.