Occurrence and persistence of "Australia" antigen determinants.

"Australia" (Au) antigens from various groups of individuals were examined for the presence of d and y determinants. Antigens from all of the 214 individuals examined were found to possess either the d or y determinant, in addition to the a determinant. With the ay antiserum employed, antibody absorption was found to be a more effective means than demonstration of spur formation for detection of the y determinant. Antigens with ad specificity predominated in a collection of sera from non-ill Tongan children and adults, but no significant differences were noted in the specificities of antigens from individuals from four different regions. Almost all of the antigens from various groups of individuals in California, including inmates of a state hospital, a group of heroin users, and hepatitis patients from San Francisco General Hospital, were of the ay specificity. With one exception, antigenic specificities were found to persist for 3 years in a group of Tongan school children. Specificities also persisted in chronic carriers from California and in hepatitis patients over the course of antigenemia. Of 15 human and 4 animal antisera examined, antibodies to the y determinant were demonstrable only in a single (human) antiserum, and antibodies to the d determinant were demonstrable in one guinea pig antiserum and one horse antiserum.