Prognostic Value of Circulating Microvesicle Subpopulations in Ischemic Stroke and TIA

AbstractPlatelet microvesicles (PMV) have previously been found elevated in acute ischemic stroke (IS) and could be biomarkers for risk of recurrence. PMV surface antigens such as P-selectin and phosphatidylserine (PS) reflect platelet activation and procoagulance. Tissue factor-positive microvesicles (TF+MV) are considered procoagulant, in particular if co-expressing PS. We enumerated MV subpopulations with these surface antigens in a cohort of 211 patients with primarily non-cardioembolic IS or transient ischemic attack (TIA) and investigated their association with long-term outcome. MV concentrations were determined by flow cytometry in the acute and convalescent phase. Primary outcome was a composite of fatal and non-fatal recurrent IS or myocardial infarction. Secondary outcomes were recurrent IS and all-cause mortality. Outcome events were obtained from Swedish registers during a follow-up of 1100 patient years. Concentrations of PS-positive and PS-negative MV populations were elevated in patients compared with healthy controls in both the acute and convalescent phase. PS+TF+PMV displayed pronounced elevations, median fold change 77 in the acute phase (p <  0.0001) but were not associated with outcome, neither were PS+P-selectin+PMV. The only subpopulation positively associated with primary outcome was PS−TF+PMV, with adjusted hazard ratio of 1.86 (1.04 –3.31,p = 0.036) by Cox regression. Unexpectedly, several MV subpopulations tended to be associated wit...
Source: Translational Stroke Research - Category: Neurology Source Type: research