
<ArticleTitle>Administration of a human monoclonal antibody (TUVIRUMAB) to chronic hepatitis B patients pre-treated with lamivudine: monitoring of serum TUVIRUMAB in immune complexes.</ArticleTitle>
<AbstractText>A human monoclonal anti-hepatitis B antibody preparation (TUVIRUMAB) was administered 6 times over a 2-week period in a dose-escalating scheme to chronic hepatitis B patients pre-treated with lamivudine. The capacity of the TUVIRUMAB antibody to "neutralize" hepatitis B surface antigen in the circulation was investigated by means of experimental enzyme-immunoassays. Monoclonal antibody conjugates enabled the detection of <prot>HBsAg</prot>, TUVIRUMAB, and <prot>HBsAg</prot>/TUVIRUMAB complexes. The results showed that (1) TUVIRUMAB was able partially to "neutralize" in vitro and in vivo, (2) <prot>HBsAg</prot>/TUVIRUMAB complexes can be traced by assays that capture the complex at either its <prot>HBsAg</prot> or its TUVIRUMAB component, (3) the final concentration of TUVIRUMAB at the end of therapy varied greatly but seemed to be related to <prot>HBsAg</prot> production at the start of therapy, (4) for at least 14 days after discontinuation of therapy, a minimal <prot>HBsAg</prot> level could be maintained in the presence of a declining TUVIRUMAB titer in patients with less than 3 microg/ml <prot>HBsAg</prot> before the start of therapy, (5) three months after therapy, all <prot>HBsAg</prot> levels had returned to pre-treatment levels and TUVIRUMAB had disappeared.</AbstractText>
