Cellular and humoral immunity in various cohorts of male homosexuals in relation to infection with human immunodeficiency virus.

The relationship between infection with human immunodeficiency virus (HIV) and various immunological parameters was studied in: (a) healthy controls; (b) homosexual individuals from the AIDS risk group without anti-HIV antibodies; (c) idem, but with anti-HIV antibodies; (d) patients with persistent generalized lymphadenopathy (PGL); (e) patients with AIDS-related syndrome; (f) patients with AIDS and opportunistic infections. In each group, consisting of 15-20 individuals, the following parameters were studied: absolute numbers of CD4+ and CD8+ cells; ratio CD4+/CD8+; cellular immune responses as measured in vivo by delayed-type hypersensitivity (DTH) and in vitro; and antibody response in vivo after immunization with a low dose of keyhole limpet haemocyanin. Healthy HIV antibody-positive individuals and patients with persistent generalized lymphadenopathy already showed a decreased CD4+/CD8+ ratio, mainly due to an increase in the number of CD8+ cells. The ratio in the AIDS-related syndrome and AIDS groups was even lower, but this was now due to low numbers of CD4+ cells while the number of CD8+ cells was normal. The lymphocyte proliferative response was low in the HIV antibody-positive group, normal in the group with persistent generalized lymphadenopathy and profoundly decreased in the AIDS-related syndrome and AIDS groups. DTH was enhanced in the PGL group and diminished in both ARC and AIDS. Compared to healthy controls, the antibody response upon immunization with a low dose of keyhole limpet haemocyanin was depressed (although not absent) in all groups studied, even in HIV antibody-negative homosexuals. In the HIV antibody-positive group, the severity of the impairment of the various parameters of immunocompetence was not related to the presence of HIV antigenaemia.