Effects of immunosuppression and disease severity upon neuropsychological function in HIV infection

Effects of immunosuppression and illness severity upon neuropsychological f unction were assessed in a group of homosexual men with AIDS across 6 month s. Participants included 62 who were seronegative (HIV-), 74 asymptomatic s eropositives (HIV+ A), 31 symptomatic seropositives (HIV+ S), 23 with AIDS defining illnesses (AIDS-DI), and 10 who were diagnosed with AIDS solely on the basis of CD4+ levels falling below 200/mm(3) (AIDS-CD4). Groups were e quivalent in age, education, and IQ. None were drug users, and none experie nced a change in disease status across the 6-month inter-test interval. The re was little evidence of cognitive decline across time. Nonetheless, after collapsing across time intervals, the AIDS-DI group had worse new-learning than all other groups. Additionally, the AIDS-DI demonstrated a greater nu mber of impaired performances than the other participant groups. The data s uggest that cognitive impairment in AIDS is unlikely due to independent con tributions of immunosuppression and illness. Rather neurobehavioral deficit s are more likely attributable to a combination of the two.