BRAIN HIV BURDEN AND LENGTH OF SURVIVAL AFTER AIDS DIAGNOSIS

Patients with AIDS in the late stages of disease can develop dementia. Previous studies have suggested HIV encephalitis is the pathological substrate of HIV-associated dementia. We hypothesized that patients wh o survive longer after the initial diagnosis of AIDS would have a high er brain HIV burden and consequently manifest dementia. We examined th e relationship between length of survival after AIDS diagnosis and the presence of HIV encephalitis or HIV-associated dementia. We studied r etrospectively the following parameters in 74 consecutive AIDS autopsi es: length of survival after AIDS diagnosis, clinical diagnosis of dem entia, and neuropathologic findings (including HIV burden assessment). Multinucleated giant cells (MNGC) were identified in 20% of the brain s studied. HIV gp41 was detected by immunocytochemistry in 54%, approx imately half of which had abundant HIV burden. Brains from all 4 patie nts who were clinically diagnosed with dementia and had no opportunist ic neuropathologic changes contained MNGC and abundant HIV burden. Sur vival after AIDS diagnosis was significantly longer in patients with M NGC (p = 0.03) or abundant HIV burden (p = 0.02). A trend toward longe r survival after AIDS diagnosis was apparent in patients with dementia , but did not reach statistical significance. These findings suggest t hat prolonged survival with immunosuppression may be a prerequisite fo r the development of HIV encephalitis.