Quantitative determination of α₂-macroglobulin in cerebrospinal fluids from various neurological diseases by enzymeimmunoassay

Abstract

Paired serum and cerebrospinal fluid (CSF) specimens from 83 patients with various neurological diseases were studied for CSF-serum α₂-macroglobulin (α₂M) quotient (Q_α2M), using a sensitive enzymeimmunoassay. The concentrations of CSF α₂M in 18 control patients were 2.55±0.92μg/ml (Mean±SD), and were significantly correlated with those of serum α₂M (r=0.65). Q_α2M was significantly correlated with CSF-serum albumin quotient (Q albumin) in 61 patients with noninflammatory neurological diseases (control, spinal spondylosis, cerebrovascular disease, degenerative diseases) as well as in 22 patients with inflammatory neurological diseases (multiple sclerosis, infectious meningoencephalitis) (r=0.73 and r=0.91, respectively). The ratio of Q_α2M/Q albumin in control patients was 0.26±0.08 (Mean±SD). There was no significant difference in the ratio of Q_α2M/Q albumin among various neurological diseases. However, the ratio of Q_α2M/Q albumin was significantly decreased in 4 patients with infectious meningoencephalitis when they recovered from the manifestations after treatment. These results indicate that Q_α2M is one of the successful tools for the evaluation of the blood-brain barrier function. Moreover, the data suggest that Q_α2M might reflect the damage of blood-brain barrier in a more sensitive fashion than Q albumin.