Antibody to Hepatitis B Core Antigen

Abstract

Two antigen-antibody systems are associated with viral hepatitis, Type B: the hepatitis B surface antigen (HB_s Ag) and antibody (anti-HB_s and the recently characterized hepatitis B core antigen (HB_c Ag) and antibody (anti-HB_c). Several populations were studied for the presence of HB_s Ag, anti-HB_s and anti-HB_c. Anti-HB_c was found in 1 per cent of volunteer HB_s Ag-negative blood donors, in 98 per cent of HB_s Agpositive blood donors and normal recipients of viral vaccines, and in 100 per cent of chronic HB_s Ag carriers. Among 16 blood donors implicated in cases of post-transfusion hepatitis, 10 were positive for anti-HB_c, among whom three were positive for HB_s Ag and three positive for anti-HB_s. The remaining six implicated donors were negative by all three tests. These data are compatible with the hypothesis that a test for antibody to HB_c Ag may be a sensitive indicator of persistent viral replication even when subdetectable amounts of HB_s Ag are circulated. (N Engl J Med 290:1336–1340, 1974)