Seroepidemiological studies of human T-lymphotropic retrovirus type III in acquired immunodeficiency syndrome

In a double-blind study, sera of 34 patients with acquired immunodeficiency syndrome (AIDS), 19 patients with lymphadenopathy syndrome, and 14 homosexual men with an increased risk of AIDS were screened for antibodies to proteins of the novel human T-lymphotropic retrovirus (leukaemia virus), HTLV-III, recently isolated from cultured T cells of AIDS patients. On a combination of a convenient and rapid enzyme-linked immunosorbent assay and a more sensitive electroblot (Western) assay, 100% of the AIDS sera were scored positive. Similarly, 84% of the lymphadenopathy patients were found to have serum antibodies to HTLV-III. A lower, but significant, proportion (21%) of healthy homosexual men with an increased risk of AIDS were also positive. No heterosexual controls, including those with heterophile antibodies during the course of infectious mononucleosis and patients with T-cell or B-cell lymphoma, had antibodies to HTLV-III. The results strongly indicate that the antibodies to HTLV-III are diagnostic of AIDS or indicate significant risk of the disease, and suggest that HTLV-III is the primary cause of human AIDS.