Australia (Hepatitis-Associated) Antigen: Physicochemical And Immunological Characteristics

This chapter discusses the discovery, characterization, immunology, and etiological significance of “Australia antigen (Au),” a new antigenic specificity appearing in the serum of patients with serum hepatitis, and carried on characteristic lipoprotein particles. In addition to its original name, given before its relationship to viral hepatitis became known, the antigen has also been given the designations, including Au(1) , SH antigen, Au/SH antigen, hepatitis antigen, and hepatitis-associated antigen (HAA). The synthesis of Au antigen, and its appearance in the serum, is specifically associated with infection by the causal agent of the SH type of viral hepatitis. The chapter discusses properties of the antigen, and of the particles which carry the Au specificity. It also discusses various serological techniques for Au antigen, such as two-dimensional double immunodiffusion (ID), complement fixation (CF), immunofluorescence (IF), reversed passive hemagglutination (RPHA) of antibody-coated red cells, immune electron microscopy (IEM), immunoelectroosmophoresis (IEOP), and radioimmunoassay (RIA).