Cerebrospinal fluid beta 2 microglobulin in patients infected with human immunodeficiency virus.

We prospectively evaluated CSF concentrations of beta 2 microglobulin (beta 2M) in 65 human immunodeficiency virus type 1 seropositive patients. The highest concentrations occurred in those with lymphoma, neurologic opportunistic infections, and acquired immune deficiency syndrome dementia complex (ADC). There was a high correlation between the CSF beta 2M concentration and ADC severity, suggesting that CSF beta 2M may be useful as a marker for the development, progression, and perhaps response to treatment of ADC. Elevated CSF beta 2M was not due to CSF pleocytosis and was usually independent of blood-brain barrier dysfunction.