Myelin basic protein in cerebrospinal fluid of patients with multiple sclerosis and other neurological diseases.

Cerebrospinal fluid (CSF) from 105 patients was analyzed by radioimmunoassay for the presence of material cross-reactive with peptide 89-169 of bovine myelin basic protein (BP). In a group of 72 multiple sclerosis patients, 52 showed higher BP content than the control group, i.e. more than 2 ng/ml CSF. Increased BP or BP fragments could be detected in CSF from almost all patients who recently (within 2 weeks) had had an acute episode, or after deterioration in the progressive form of the disease. Fifteen to 30 days after the onset of exacerbation or in a stable period, BP content decreases and in the slowly progressive form was in the range of the control group with one exception. BP content was also elevated in the CSF of patients with other neurological diseases. The presence of BP in the CSF from patients with isolated retrobulbar neuritis is of particular interest. Thus the presence of material cross-reactive with BP fragment 89-169 is not specific for multiple sclerosis, but is a useful parameter in diagnosis and evaluation of MS.