Concurrently Circulating Hepatitis B Surface Antigen and Heterotypic Anti-HBs Antibody

Abstract

In the early days of testing for hepatitis B surface antigen (HB₈Ag) ² and the homologous antibody (anti-HB₈), there were reports of antigen and antibody co-existing in the same serum specimen (1, 2). Their subspecificities were not determined; but their homotypic character was evidently inferred, and in keeping with this idea were certain results obtained by complement fixation (3), and electronmicroscopic observations of circulating complexes apparently made up of HB₈Ag-positive Australia particles and antibody molecules (4). Some recent studies have adduced further evidence for the existence of such complexes (5), whereas others have failed to substantiate the concurrent presence of HB₈Ag and homologous anti-HB₈, at least in the blood of asymptomatic carriers of the antigen (6). With the definition of distinct antigenic phenotypes of HB₈Ag, there arose the theoretical possibility that Australia particles of one phenotype might co-circulate with free anti-HB₈ antibody directed against antigenic configurations characteristic of a different phenotype.