Evidence of platelet activation in multiple sclerosis

William A Sheremata¹ , Wenche Jy² , Lawrence L Horstman² , Yeon S Ahn² , J Steven Alexander³ and Alireza Minagar⁴

¹Multiple Sclerosis Center and Department of Neurology Miller School of Medicine, University of Miami, Miami, Florida, USA

²Wallace Coulter Platelet Laboratory, Division of Hematology and Oncology, Department of Medicine, Miller School of Medicine, University of Miami, Miami, Florida, USA

³Department of Cellular and Molecular Physiology, Louisiana State University Health Science Campus, Shreveport, Louisiana, USA

⁴Department of Neurology, Louisiana State University Health Science Campus, Shreveport, Louisiana, USA

author email corresponding author email

Journal of Neuroinflammation 2008, 5:27doi:10.1186/1742-2094-5-27


Published:	27 June 2008

Abstract

Objective

A fatality in one multiple sclerosis (MS) patient due to acute idiopathic thrombocytopenic purpura (ITP) and a near fatality in another stimulated our interest in platelet function abnormalities in MS. Previously, we presented evidence of platelet activation in a small cohort of treatment-naive MS patients.

Methods

In this report, 92 normal controls and 33 stable, untreated MS patients were studied. Platelet counts, measures of platelet activation [plasma platelet microparticles (PMP), P-selectin expression (CD62p), circulating platelet microaggragtes (PAg)], as well as platelet-associated IgG/IgM, were carried out. In addition, plasma protein S activity was measured.

Results

Compared to controls, PMP were significantly elevated in MS (p < 0.001) and CD62p expression was also markedly elevated (p < 0.001). Both are markers of platelet activation. Platelet-associated IgM, but not IgG, was marginally elevated in MS (p = 0.01). Protein S in MS patients did not differ significantly from normal values.

Conclusion

Platelets are significantly activated in MS patients. The mechanisms underlying this activation and its significance to MS are unknown. Additional study of platelet activation and function in MS patients is warranted.