Complement-fixing antibrain antibodies in multiple sclerosis. Comparison of their occurrence in cerebrospinal fluid and serum.

Cerebrospinal fluid (CSF) and serum samples from 40 multiple sclerosis (MS) patients and 48 control patients were examined by a microcomplement fixation test for the presence of antibodies against saline extracts of human brain. When tested with an IgG content standardized in 100 mg per 100 ml, 13 of the MS CSF and one of the corresponding MS sera were positive, whereas none of the control specimens were positive. The antibody was shown to be highly organ specific when tested against extracts of myocard, spleen, kidney and peripheral nerve. Chromatographic experiments showed the antibody to belong to the IgG class. It was concluded that the antibody was probably synthesized intrathecally in 12 and extrathecally in one MS patient.