Antibody to human T cell leukaemia virus type III in Australian homosexual men with lymphadenopathy

Abstract

Sera from Australian homosexual men with idiopathic lymphadenopathy syndrome (ILS), a disease related to the acquired immune deficiency syndrome (AIDS), were tested for antibodies to two serotypes of human T leukaemia virus (HTLV), types I and III; type III is the type recently recognized in the USA as being associated with AIDS. Sera were tested also from other homosexual men and heterosexual controls. Antibody to high titre to HTLV-III was present in the serum of all six subjects with ILS. In contrast, antibody to low titre was present in only one of six healthy homosexual men and in one of five homosexual men with immunodeficiency but no lymphadenopathy. Antibody to HTLV-III was not detected in serum in the one subject with AIDS who was tested, but was detected in his healthy sexual partner. Antibody to HTLV-I, earlier believed to be related to AIDS, was lacking in all subjects. These results suggest, in an Australian setting, that infection with HTLV-III is the cause of ILS and, by inference, may also be the cause of AIDS. We suggest that there are as yet undetermined factors associated with male homosexual practices which cause immunodeficiency which, in turn, increases susceptibility to HTLV-III, the actual causal agent of ILS and, probably, AIDS.