Eight year prospective study of HIV infection in a cohort of homosexual men--clinical progression, immunological and virological markers.

Three hundred and fourteen homosexual/bisexual men at risk for human immunodeficiency virus (HIV) infection (170 seroprevalent HIV-positive, 144 seronegative) were prospectively studied over 8 years to assess rates of HIV infection and disease progression, in conjunction with cellular and HIV serological markers. In HIV-positive subjects, CD4+ lymphocyte counts rose strikingly during the period surrounding seroconversion, then fell progressively over the intervening period to a mean level of 300 cells/mm3 when AIDS developed. Changes in CD8+ lymphocyte counts were less consistent. The trend for HIV serological markers over the study period was of progressive decline in the proportion of subjects with anti-p24 antibody, associated with an increase in the proportion of subjects with detectable HIV antigenaemia. However, only 45% of subjects tested had lost anti-p24 antibody by the time of AIDS diagnosis, and HIV antigen was detectable up to 4 years before this. Different HIV serological patterns were also observed in subjects presenting either with Kaposi's sarcoma or opportunist infections. Our data support the continued use of cellular and virological markers in the evaluation of HIV disease; however, the variability observed in this study highlights their limited ability in predicting specific clinical events. Care should therefore be taken to encompass both clinical and laboratory information in the medical assessment of the HIV-infected individual.