CSF myelin basic protein in multiple sclerosis.

Cerebrospinal fluid (CSF) from 221 patients with multiple sclerosis (MS) and 85 patients with other neurological disorders (OND) was examined using a competitive radioimmunoassay for myelin basic protein (MBP) immunoreactivity. MBP was found in 46 of 55 MS patients (84%) examined within six weeks of relapse but in only 11 of 85 patients (13%) with OND. There was a significant correlation between the concentration of MBP in the CSF and relapse severity in patients seen within four weeks of the onset of symptoms (p less than 0.01). Of 44 patients in remission, MBP was detected in 12, and these patients had a significantly higher tendency to subsequent relapse (p less than 0.05). In 72 patients with progressive disease the presence of MBP in the CSF reflected the confidence of clinical diagnosis. The results of this study suggest that measurement of MBP in the CSF gives an objective method of monitoring disease activity in patient with MS.