Long-term human immunodeficiency virus infection in asymptomatic homosexual and bisexual men with normal CD4+ lymphocyte counts: immunologic and virologic characteristics

Froma prospective cohortstudy,24asymptomatic menwereidentifiedwhohad beenantibody positive for human immunodeficiency virus (HIV) for at least 5 years(median = 9.1) with CD4+ lymphocyte counts ~400 cells/mm', Of these "nonprogressors, " 23 (96%)had evidence of HIV infectionbyeithermvculture or the polymerase chain reaction(PCR)forHIV DNA,although only1(4%)had a positive assayforHIVRNA(byPCR)and noonewaspositive forp24antigen. Compared with 24 antibody-negative men and 14men with AIDS, nonprogressors had higher CD8+ counts and lower natural killer cellactivity. Nonprogressors had higher132-microglobulin levels than did seronegative controls, suggesting somedegree ofimmunesystem activation. Com-pared with men with AIDS, nonprogressors seemedto havea strongerantibodyresponse to six different HI\'-relatedproteinsbut did not differsignificantly in neutralizing antibody or antibody-dependent cellular cytotoxic activity. Natural history studies of human immunodeficiency virus (HIV)-infected individuals indicate that duration of infection is an important determinant of developing AIDS [1-5]. For example, in our prospective cohort study of homosexual an