Immune Response in Patients Who Received Blood Containing Serum Hepatitis Antigen

Conventional methods for detection of SH (Australia antigen, HAA) antigen and corresponding antibody, such as agar gel diffusion (AGD), immunoelectroosmophoresis (IEOP), and complement fixation (CF), have failed to incriminate hepatitis virus type B in a major portion of cases of posttransfusion hepatitis.^1,2 It has not been possible to determine whether this reflects only the inadequate sensitivity of these assay methods or whether these findings reflect the role of other viruses, lacking an association of the SH antigen, in the etiology of posttransfusion hepatitis. It has been recognized that introduction of more sensitive methods, such as radioimmune assay³ or hemagglutination inhibition (HAI)⁴ may provide an answer. We report an investigation of patterns of immune response as shown by passive HA technique in 35 patients inadvertently transfused with blood containing SH antigen. Serological evidence of infection with hepatitis virus type B has been obtained in 34 of the 35