Intrathecal humoral immunologic response in neurologically symptomatic and asymptomatic patients with human immunodeficiency virus infection

We analyzed the intrathecal humoral immunologic response in 42 human immunodeficiency virus (HIV)-infected patients. Eighteen patients had clinical neurologic abnormalities, while the remaining 24 patients were neurologically symptom-free. Nine of the neurologically symptomatic patients at early infection had slight neurologic dysfunction; in nine other subjects at late infection, the neurologic impairment was moderate or severe. When compared with symptom-free patients, neurologically symptomatic patients had increased intra-blood-brain barrier (BBB) HIV-specific IgG (p less than 0.001) and total IgG synthesis (p less than 0.01) with oligoclonal bands (OCBs) in the CSF and/or serum (11/18 versus 3/24). At early stages of the infection, neurologically symptomatic patients showed increased total intrathecal IgG synthesis (9/9) coincident with OCBs in the CSF and serum (7/9) and slight mononuclear pleocytosis (7/9), but less frequent HIV-specific IgG production within the CNS (6/9). In advanced infection, the number of neurologically symptomatic patients with intrathecal HIV-specific IgG synthesis (8/9) was higher, while the number of those with increased total intra-BBB IgG synthesis (5/9; p less than 0.01), OCBs (4/9), and increased CSF leukocyte count (1/9; p less than 0.001) was lower than at early infection. Our data suggest humoral intra-BBB immunoactivation at early stages of HIV infection followed by declining B cell response within the CNS at advanced infection.