Intrathecal reactivity for myelin components precedes development of neurological symptoms in AIDS patients

The central nervous system is considered an early and common target for the human immunodeficiency virus type 1 (HIV-1). Serum and cerebrospinal fluid (CSF) from 20 HIV positive patients, including 14 with AIDS-dementia complex (CDC stage IV) and 6 asymptomatic individuals (CDC stage II) were analyzed by enzyme immunoassay for detection of antibodies to native myelin basic protein (MBP) and for the amino acid sequence 68-84 exposed after partial degradation of native MBP. Control groups included HIV-1 negative patients with degenerative and/or vascular dementia, chronic multiple sclerosis (MS) and individuals without any sign of neurological or cognitive disturbances. As opposed to control groups, serum and CSF samples from MS and HIV-1 infected patients showed several oligoclonal bands running in the gamma region. AIDS-dementia complex (ADC) patients had increasingly high intrathecal IgG specific antibody titers for the amino acid sequence 68-84 of MBP. Marked intrathecal antibody production for myelin components was also detected in the majority of HIV-1 infected asymptomatic individuals. Such alteration paralleled development of cognitive deficits, neurological abnormalities and appearance of CNS demyelinating plaques. Preferential immune recognition of this myelin epitope within the CSF during early stages of HIV-1 infection might point to an ongoing process of active demyelination and ultimately indicate subclinical CNS involvement.