Decreased helper T lymphocytes in homosexual men. II. Sexual practices

Abstract

In June 1982, the sexual practices of 245 homosexual male outpatients of private physicians were evaluated in relationship to decreased numbers of helper T lymphocytes, an abnormality that is characteristic of the acquired immunodeficiency syndrome (AIDS). Three risk groups were defined a priori--85 high-risk men from central Manhattan ("New York"), 96 intermediate-risk men from Washington, DC, with AIDS-area homosexual contacts ("Washington-exposed"), and 64 low-risk Washington, DC, men without such contacts ("Washington-unexposed"). An increasing number of homosexual partners was correlated with decreasing helper T-cell counts (R = -0.29, p = 0.009) and decreasing helper:suppressor T-cell ratios (R = -0.32, p = 0.005) in the entire study group combined and in New York subjects separately. Suppressor T-cell counts were unrelated to the number of partners in all three groups. Increasingly frequent receptive anal intercourse correlated with decreasing helper T-cell counts most clearly in the New York City group (R = -0.23, p = 0.04), somewhat less so in the Washington-exposed group (R = -0.18, p = 0.07), and not at all in the Washington-unexposed group (R = -0.09, p = 0.48). This association persisted in the New York and Washington-exposed groups after adjusting for seven other sexual practices, the number of homosexual partners, and five other potentially confounding variables. A transmissible agent associated with receptive anal intercourse best explains these data. The cause of these low helper T-cell counts may also be the cause of AIDS.