Cerebrospinal fluid beta 2-microglobulin in neurological disorders.

Beta-2-microglobulin was measured in specimens of cerebrospinal fluid (CSF) collected from 167 patients classified in 14 diagnostic categories at an outpatient Department of Neurology. In the control group of 29 subjects without any obvious disease of the nervous system, the concentration of beta-2-microglobulin was 1.15 +/- 0.37 mg/1 (M +/- s.d.). The concentration was almost significantly elevated in the groups with fresh brain infarct, central nervous system infection, and polyneuropathy. The serum concentrations of beta-2-microglobulin did not differ significantly among these diagnostic categories. The mean ratio between CSF and serum beta-2-microglobulin was 0.79 +/- 0.32 in the control group and more than 1.0 in the patients with brain infarcts, CNS infections and spinal paresis, but the differences were not statistically significant.