RELATIONSHIP BETWEEN HUMAN IMMUNODEFICIENCY VIRUS-ASSOCIATED DEMENTIAAND VIRAL LOAD IN CEREBROSPINAL-FLUID AND BRAIN

Cerebrospinal fluid (CSF) human immunodeficiency virus (HIV) RNA level s were measured with the Nucleic Acid Sequence-Based Amplification (NA SBA) assay to determine the relationship with neurological status; 37 subjects with HIV dementia (HIV-D) were compared with 77 with HIV with minor neurological signs (HIV-MCMD) and 93 neurologically normal HIV- seropositive individuals (HIV-NML). The NASBA assay had a lower limit of detection of 100 copies per milliliter. Mean CSF log HIV RNA levels were significantly higher in those with dementia after adjusting for CD4 count and were correlated with dementia severity. Plasma levels di d not distinguish comparably immunosuppressed subjects with or without dementia. CSF and plasma RNA levels were significantly intercorrelate d for subjects with CD4 counts <200/mm(3) and also correlated inversel y with CSF beta(2)-microglobulin. CSF RNA levels were independent of C SF pleocytosis or antiretroviral exposure. Brain RNA levels were consi stently higher than CSF but correlated with CSF values for dementia su bjects. The NASBA assay can be used reliably to determine HIV RNA leve ls in CSF, brain, and plasma samples. CSF HIV RNA may be a surrogate m arker for brain infection, based on the observed correlation with brai n levels. The association between plasma HIV RNA and CSF levels of HIV and beta(2)-microglobulin suggests that both viral load and CNS immun e activation are important determinants of neurological disease.