Quantitative assessment of serum hepatitis B e antigen, IgM hepatitis B core antibody and HBV DNA in monitoring the response to treatment in patients with chronic hepatitis B.

Abstract

Virological response to treatment of chronic hepatitis B is defined as the loss of serum hepatitis B virus DNA (HBV DNA) and hepatitis B e antigen (HBeAg). The quantitative measurement of HBV DNA is useful for monitoring and predicting the response to therapy with interferon-alpha (IFN-alpha). In this study, we evaluated whether quantitative measurement of serum HBeAg and IgM antibody to hepatitis B core antigen (HBcAb) could also be used in this manner. Using a microparticle-capture enzyme immunoassay (IMx), a standard curve of fluorescence rate vs HBeAg concentration was constructed to provide quantitative results. The IgM HBcAb index was also measured using a microparticle enzyme immunoassay and serum HBV DNA was measured by a solution hybridization assay. We studied 48 patients who were initially positive for HBeAg and HBV DNA and who were treated with IFN-alpha2b. Their sera were serially evaluated for HBeAg concentration, and results were compared with HBV DNA levels. In the 14 patients who responded to IFN, similar disappearance curves were observed with good intraindividual correlation between the levels of the two markers. In the 34 non-responders, HBeAg levels decreased during treatment but never became negative; HBV DNA levels also decreased during treatment and became transiently undetectable in six patients, falsely suggesting treatment success. The IgM HBcAb index paralleled changes in alanine aminotransferase (ALT) concentration and did not provide additional information. Multiple logistic regression indicated that baseline ALT and HBeAg concentrations were independent predictors of the response to treatment and the addition of neither HBV DNA nor IgM HBcAb improved the model. We conclude that quantitative measurement of HBeAg provides information similar to that of HBV DNA in monitoring and predicting the response to treatment; this technique could be readily adaptable to clinical laboratories.