Specific detection of anti-HBc antibodies with an enzyme immunoassay using recombinant HBcAg and monoclonal antibodies.

An enzyme immunoassay for the detection of total anti-HBc antibodies in undiluted serum samples was developed. This assay utilizes an anti-HBc monoclonal antibody and a recombinant HBc antigen. The results of the clinical validation are now reported. A total of 1,301 sera were tested using both the Recombinant TOTAL HBc Ab EIA and a reference assay. The specificity was evaluated on a panel of 573 normal human sera and human sera from subjects with pathological findings unrelated to a hepatitis B virus infection. The sensitivity was studied on a total of 455 sera from HBV infected patients at different stages of infection. The final results indicate 99.8% sensitivity and 99.8% specificity. In addition, 273 sera with either isolated anti-HBc antibodies or with anti-HCV antibodies were tested. The agreement between the Recombinant and the reference assay for these two populations, 96.6 and 90.1%, respectively, is discussed.