Abstract
A direct binding enzyme‐linked immunosorbent assay (ELISA) was established for quantitative determination of serum IgM antibodies towards a synthetic peptide corresponding to a selected segment (14‐21) of the preS2‐gene product containing an immunodominant linear B‐cell epitope. The prevalence of IgM anti‐preS2 (14‐21) antibody titers >1, 000 for hepatitis B e antigen (HBeAg)‐positive patients with chronic hepatitis B virus (HBV) infection was 38% (22/58) and 10% (2/21) for HBeAg‐negative subjects (P< 0.005).
IgM anti‐preS2 (14‐21) reactivity was detected during the clinical course of chronic HBV infection and IgM anti‐peptide antibody titers declined and disappeared before spontaneous HBe/anti‐HBe seroconversion.
Recombinant interferon (IFN)‐alpha 2b with an antecedent short course of corticosteroids was administered to eight Chinese patients with chronic HBV infection. The IgM anti‐preS2 (14‐21) reactivity was monitored consecutively during treatment and patients were followed for more than 1 year. A close association between the presence of pretreatment IgM anti‐preS2 (14‐21) in serum and the capacity to respond favorably to the combined prednisone/IFN‐alpha 2b therapy was detected. The IgM anti‐preS2 (14‐21) titers decreased during treatment with subsequent loss of detectable antibodies 8‐16 weeks after the initiation of therapy. This decrease was concomitant with an alanine aminotransferase (ALT) augmentation preceding the disappearance of HBV‐DNA and anti‐HBe seroconversion. Long‐term remission was not observed in treated patients who lacked detectable levels of pretreatment IgM anti‐preS2 (14‐21) in the circulation.
These results demonstrate that a substantial cohort of HBeAg‐positive chronic hepatitis B pa‐tients have IgM antibodies towards a synthetic B‐cell epitope representing a dominant antibody binding site within the envelope of HBV. They indicate that IgM anti‐preS2 (14‐21) titers reflect the immunosuppressive effect on IgM secretion during the combined prednisone/IFN‐α 2b therapy. Further studies are needed to determine the usefulness of a quantitative assay for IgM anti‐preS2 (14‐21) measurements in predicting the response to treatment with interferon alone or preceded by a short course of prednisone in patients with chronic hepatitis B. © 1995 Wiley‐Liss, Inc.