Changes of chronic hepatitis C virus anti-core and envelope antibodies by interferon therapy

We measured the levels of three antibodies against core (JCC-2), E1 (E1–5), and $\text{E2}\text{NS1}$ (E2-1) hepatitis C virus (HCV) before and after interferon (IFN) therapy in 22 patients with chronic hepatitis C and assessed the relationship between the changes in these antibody titers and the response to IFN. The titers of serum JCC-2 and E2-1 antibodies before the IFN therapy did not show any significant relationship with IFN efficacy. In contrast, the titer of E1–5 antibody was significantly lower in the complete responder (CR) group than in the non-responder (NR) group. The JCC-2 antibody titer of the CR group to IFN therapy showed a significant decrease immediately, at 6 months and 1 year after the completion of IFN administration. However, that of the NR group either did not change or rose again 6 months or 1 year after therapy following an immediate short-term decrease. Thus the E1–5 antibody titer before IFN therapy and the JCC-2 antibody titer during IFN therapy seems to be a good indicator of IFN efficacy. In contrast, the E2-1 antibody did not correlate with IFN efficacy.