Comparison of platelet count, platelet activation marker CD62P expression, PMP, and protein S between controls and MS patients. (A) Mean platelet counts did not differ between the MS and control groups. (B) Elevation of platelet activation marker CD62p in the MS group was highly significant, *P < 0.001. Not shown or included in the analysis was one extremely high value (60.6), possibly a technical error. (C) PMP counts in the MS patients were significantly higher than controls, *p < 0.001. Not shown or included in the analysis was one very high outlying value (25.2). (D) Protein S activity (% control) did not differ significantly between MS and controls. All values are expressed as mean ± SD. The institutional control values (mean ± SD) of platelet count and protein S activity were obtained from the laboratory of University of Miami Hospital and Clinics, and are not shown as individual dots because the numbers are too large.