Cerebrospinal fluid p24 antigen levels and intrathecal immunoglobulin G synthesis are associated with cognitive disease severity in HIV-1

To test the hypothesis that selected cerebrospinal fluid (CSF) markers [intrathecal immunoglobulin G (IgG) synthesis rate, oligoclonal IgG bands, and p24 antigen levels] are associated with the presence and severity of clinical HIV-1 neurologic disease. CSF and blood parameters from 142 HIV-seropositive subjects from the baseline examination of a longitudinal study were measured and analyzed in relationship with clinically derived cognitive impairment groups (none, mild, moderate) and with other neurologic and clinical classification groups. Subjects with opportunistic infections, lymphomas or neurosyphilis were excluded. The mean intrathecal IgG synthesis rate and mean CSF p24 antigen levels both differed significantly among cognitive impairment groups; more impairment was associated with a higher rate or level. Mean CSF p24 antigen levels were significantly higher in HIV-1-seropositive subjects with any HIV-1 neurologic disease than in subjects without neurologic disease. In contrast, there were no significant differences among seropositive groups in any CSF parameter when stratified by systemic disease classification (asymptomatic HIV-seropositives, AIDS-related complex, or AIDS), independent of neurologic status. We conclude that there may be a relationship between the severity of HIV cognitive disease and increasing levels of intrathecal IgG synthesis and CSF p24 antigen levels.