Comparison of platelet-associated IgG and IgM between controls and MS patients. Results are expressed as percentage of platelets positive for the indicated immunoglobulin, where positive is defined as >3SD above the mean for normal subjects in this laboratory by the procedure referenced in the methods section. (A) Results for platelet-associated IgG showed no significant difference between the MS group and controls. Value were, ± SD: 2.7 ± 1.3 for controls vs. 3.4 ± 2.7. (B) In contrast, mean platelet associated IgM was significantly higher in the MS group, *p < 0.01. Values were, ± SD: 3.4 ± 1.3 for controls vs. 7.8 ± 6.5 for MS. Not shown or included in analysis were 2 very high outlying values (55.9, 65.9).