Progressive cellular immune impairment leading to development of AIDS: two-year prospective study of HIV infection in drug addicts.

We have studied immunological, serological and clinical abnormalities in 264 HIV-positive and HIV-negative drug abusers. Ninety percent of the 264 drug addicts (mean age 26 +/- 0.8 years) were found to have HIV antibodies and there was a significant increase (P less than 0.01) in the frequency of HIV antibody positivity with increasing duration of exposure to parenteral drug abuse. There was a very strong correlation between the progressive decline of the mean T4+ helper/inducer cells and T4+/T8+ ratio, the low response to pokeweed mitogen and the more severe clinical manifestations of HIV infection. Impairment of delayed-type hypersensitivity reaction to recall antigens was only seen in group IV as defined by the Center for Disease Control. Within group IV, anergy was found to be highly associated (83%) in patients with opportunistic infections. All other HIV-positive addicts from groups II and III, as well as HIV-negative addicts had normal in vivo responses to test antigens. We have also analysed in a prospective follow-up lasting 6-24 months, the evolution of HIV infection in a cohort of 50 HIV-antibody-positive drug addicts. Thirty-two percent showed clinical progression and most of the drug addicts that proceeded to full-blown AIDS developed anergy (82%) prior to clinical deterioration with development of opportunistic infections. We conclude, that in seropositive drug addicts a low absolute count of helper/inducer cells (mean +/- s.e. = 243 +/- 48 cells/mm3), a low response to pokeweed mitogen and anergy are predictive markers of progression to AIDS.