Current tests for antibody to hepatitis b core antigen used to screen donors for non-A, non-B hepatitis are comparable to the original radioimmunoassay for hepatitis B core antigen.

Prospective studies have shown a relationship between the transfusion of donor blood which is positive for antibodies to hepatitis B core antigen (anti-HBc) and an increased incidence of non-A, non-B hepatitis. The anti-HBc test was selected on the assumption that epidemiologic circumstances predisposing donors to hepatitis B infection also might favor exposure to non-A, non-B hepatitis. Current radioimmunoassays (RIA) and enzyme-linked immunoassays (EIA) for anti-HBc utilize hepatitis B core antigen (HBcAg) prepared by recombinant DNA technology, whereas the original RIA anti-HBc assay used HBcAg derived from hepatitis B virions. In the current study, 1329 sera were evaluated of which 23.3 percent were anti-HBc positive. The results indicate that sensitivity, specificity, and positive and negative predictive values of the current EIA and RIA tests for anti-HBc (Abbott Diagnostic Laboratories) are virtually identical to the original RIA test kit. In addition, all donor samples (128 specimens) administered to 57 cases of non-A, non-B hepatitis that were prospectively followed at Baylor College of Medicine for the Transfusion-Transmitted Viruses (TTV) Study group were retested with the EIA-recombinant anti-HBc assay. All 21 samples which were reactive in the original RIA anti-HBc test also were positive by the current EIA procedure. One sample was EIA positive/RIA negative, and 106 other samples were negative by both assays. Thus, commercial anti-HBc kits based on HBcAg derived by recombinant DNA technology, should retain their predictive value for reducing the incidence of non-A, non-B hepatitis as described in the prospective studies.