Comparison of spinal fluid beta 2-microglobulin levels with CD4+ T cell count, in vitro T helper cell function, and spinal fluid IgG parameters in 163 neurologically normal adults infected with the human immunodeficiency virus type 1.

Beta 2-microglobulin levels were measured in the cerebrospinal fluid (CSF) and serum of 163 human immunodeficiency virus-positive (HIV+) persons with normal neurologic physical examinations. None were on antiretroviral therapy. Only 3% had a positive CSF HIV p24 antigen test. The CSF beta 2-microglobulin levels increased as the CD4+ T cell count decreased. Intrathecal production of beta 2-microglobulin was suggested by finding CSF concentrations greater than serum concentrations in 15% of patients. The CSF beta 2-microglobulin levels rose as in vitro T helper cell function deteriorated, independent of CD4+ T cell count. CSF beta 2-microglobulin levels paralleled CSF IgG, IgG index, and IgG synthesis. Higher CSF beta 2-microglobulin levels were found in persons with positive CSF oligoclonal bands. CSF beta 2-microglobulin concentration may serve as a marker for subclinical neurologic damage due to HIV. If this is established, defining the effect of anti-HIV interventions on CSF beta 2-microglobulin would be warranted.