Anti-envelope 1 and 2 immune response in chronic hepatitis C patients: Effects of hepatitis B virus co-infection and interferon treatment

Antibodies against envelope glycoprotein 1 and 2 (anti-E1/E2) have been suggested to influence HCV replication levels. Hepatitis B virus (HBV) may interfere with hepatitis C virus (HCV) replication. At present there are no data on anti-E1/E2 antibody responses or on the effect of interferon (IFN) treatment in HBV-HCV co-infection. Accordingly, we evaluated serum anti-E1/E2 antibodies in 50 patients (median age, 26.5; males, 30) with chronic hepatitis, 38 with HCV and 12 with HBV-HCV co-infection, who had undergone alpha-IFN treatment. Before starting IFN, the HCV group showed higher HCV-RNA levels (bDNA assay) than the HBV-HCV group (median 3.75 vs. 0.64 x 10(6) Eq/ml, respectively; P<0.05). Similarly, the anti-E2 levels (EIA assay) were higher in the HCV group than in the HBV-HCV (mean SD, 53.8 +/- 54.58 vs. 24.5 +/-41.50 U/ml, respectively; P< 0.02), and the prevalence of anti-E2 was also higher in the HCV group (94 vs. 58%, respectively; P< 0.007). No correlation was found between anti-E1/E2 antibodies and the HCV-RNA levels. The prevalence of E1/E2 antibodies was similar in the different HCV genotypes. Higher baseline levels of anti-E2 antibodies and a decrease or disappearance of anti-E2 antibodies during IFN were associated with IFN sustained response in both groups, whereas no reduction in the anti-E1/E2 levels was observed in non-responders. The data show that HBV co-infection influences both HCV replication and the anti-E1/ E2 antibody production. High pre-treatment levels of anti-E2 antibodies and their decrease or disappearance during interferon treatment are often associated with HCV clearance in sustained responders, irrespective of the HCV genotype. (C) 2004 Wiley-Liss, Inc.