EMBARGOED FOR RELEASE UNTIL 4 PM ET, May 21, 2001
New Marker for Disease Activity in Multiple Sclerosis
St. Paul, Minn. -
Scientists have identified a potential new marker for MS disease activity, according to a study published in the May 22, 2001 issue of Neurology, the scientific journal of the American Academy of Neurology. “We’ve discovered in the plasma of MS patients the elevation of endothelial microparticles (EMP, membrane-derived vesicles), a marker of endothelial dysfunction which can then be tracked and used to study disease activity,” say authors Alireza Minagar, MD, and Wenche Jy, PhD, of the University of Miami, School of Medicine. Previous studies have shown that endothelial dysfunction (dysfunction of the layer of cells that lines the blood vessels), measured by soluble markers may contribute to the progression of MS. While these markers have been identified as possible evidence of blood brain barrier (BBB) damage, the present study provides a new method to assess endothelial dysfunction. This study measured endothelial microparticles (EMP) released to plasma in 50 MS patients and 48 control subjects using flow cytometry. Also investigated was whether plasma from MS patients could induce shedding of endothelial microparticles from brain microvascular endothelial cell culture. “Our results show that exacerbation of MS is associated with endothelial dysfunction as reflected by shedding of a platelet-endothelial cell adhesion molecule (CD31) + EMP into circulation. This is not seen during remission,” said Minagar. Through this study, elevation of CD31+ EMP is clearly associated with exacerbations of MS and therefore, measurement of CD31 + EMP may be complementary to using magnetic resonance imaging in detecting disease activity. The plasma factor(s) that actually induce CD31+EMP release during acute exacerbation of MS remain to be definitively identified. Concludes Jy, “Our data further supports accumulating evidence that MS exacerbations result from acute inflammation leading to activation of endothelium at the BBB, facilitating passage of leukocytes into the central nervous system.”