Cerebrospinal fluid autoantibodies to myelin basic protein in multiple sclerosis patients. Detection during first exacerbations and kinetics of acute relapses and subsequent convalescent phases.

In order to determine if free (F) and bound (B) levels of autoantibodies to myelin basic protein (anti-MBP) are present from the onset of multiple sclerosis (MS), 201 patients referred to our clinic were clinically divided into a group diagnosed as having an initial MS relapse and a group of non-MS controls. Ninety-four of 106 patients thought to have an initial MS relapse had increased CSF anti-MBP, while only 14 of 95 controls had elevated antibody levels; 9 of these 14 positive controls were subsequently shown to have MS by magnetic resonance imaging and/or clinical follow-up. CSF anti-MBP was more frequently abnormal than 3 estimates of intrathecal IgG synthesis in the group with suspected MS. Kinetics of F and B CSF anti-MBP were determined in a group of 29 patients with clinically definite MS during an acute relapse and 97.4 +/- 54 days later in the subsequent convalescent phase when in clinical remission. F and B anti-MBP levels were highly dependent on the timing of the CSF sampling; generally, as patients entered into clinical remission F anti-MBP declined, B antibody levels rose and F/B anti-MBP ratios initially above unity gradually declined towards zero. These data suggest that anti-MBP may be involved in the mechanism of MS.