Myelin basic protein antibodies in the serum and CSF of multiple sclerosis and subacute sclerosing panencephalitis patients.

A solid-phase radioimmunoassay was developed for the detection of myelin basic protein antibodies of immunoglobulin G (IgG) class. Purified basic protein of myelin (MBP) was adsorbed onto polystyrene beads, followed by incubation in dilutions of serum or cerebrospinal fluid (CSF). 125I-labelled anti-human IgG was used to quantify antibodies bound to the solid-phase. The assay was optimized in tests with rabbit antibodies to MBP and with 125I-labelled anti-rabbit IgG. Serum and CSF specimens from 41 multiple sclerosis (MS), 16 subacute sclerosing panencephalitis (SSPE) and 58 control patients were tested for MBP antibodies. No statistically significant differences were found between MS and control patient groups, but the subgroup of acute MS patients had slightly elevated (P 0.02) antibody levels in their CSF specimens. The SSPE patients had markedly elevated levels (P 0.001) of antibodies to MBP in their CSF specimens.