Long term response to interferon treatment in chronic hepatitis C patientsis associated with a significant reduction in anti-E1 envelope antibody titers

Interferon (IFN) alfa has been used widely for the treatment of chronic hep atitis C virus (HCV) infections but only a small number of patients treated have shown a sustained biochemical and virological response. Anti-envelope E1 and E2 antibody titers were assessed retrospectively before, during, an d after treatment with IFN in order to evaluate their usefulness for the pr ediction and monitoring of therapy outcome in 115 patients infected chronic ally with HCV genotype 1b. At baseline, E2 induced more frequent and strong er immunogenic responses than E1, irrespective of patient response to thera py. E1 and E2 antibodies also tended to be higher in patients with a long-t erm or a transient response to IFN treatment than in patients who were abso lute non-responders. In most patients, E1 and E2 antibody levels tended to be lower after treatment. This reduction was most pronounced and occurred m ost frequently in long-term responders to therapy. In this patient group, t he reduction of E1 antibodies was more pronounced than that of E2 antibodie s. In contrast to E2 antibodies, the decrease of E1 antibodies could alread y be observed at the end of therapy (week 24) and was significantly larger (p<0.05) than that observed in relapsers and non-responders. Thus, a sustai ned elevation of E1 antibodies seems to be associated with ongoing infectio n even when HCV RNA levels were undetectable in serum. Monitoring of E1 ant ibody titers may represent a useful additional marker to discriminate susta ined responders from those who relapse in patients receiving interferon the rapy. J. Med. Virol. 60:126-132, 2000. (C) 2000 Wiley-Liss, Inc.