Kaposi's sarcoma in three HIV-1-infected cohorts.

We describe the Kaposi's sarcoma (KS) experience in three cohorts of homosexual men, subjects with hemophilia, and human immunodeficiency virus type 1 (HIV-1) seroconverters. The risk of KS was higher in HIV-1-infected homosexual men from New York City as compared with Washington, D.C. and was very low in the hemophilia subjects. While KS accounted for a decreasing proportion of AIDS cases in homosexual men, the absolute risk per year did not diminish. Survival was similar after diagnosis of KS vs. opportunistic infection including Pneumocystis carinii pneumonia. Percent CD4+ and CD8+ T cells, and beta 2-microglobulin levels were less abnormal in subjects who later developed KS than in those who developed opportunistic infections; conversely, serum neopterin abnormalities were greater in those who developed KS. The additional risk of KS in homosexual men may explain their apparently higher incidence of AIDS. Further investigation of the differences in intermediate markers of KS and opportunistic infections may shed light on the pathogenesis of these particular manifestations of AIDS.