1. Prognostic Value of Circulating Microvesicle Subpopulations in Ischemic Stroke and TIA.
- Author
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Lundström A, Mobarrez F, Rooth E, Thålin C, von Arbin M, Henriksson P, Gigante B, Laska AC, and Wallén H
- Subjects
- Aged, Blood Platelets pathology, Female, Humans, Male, Prognosis, Prospective Studies, Thromboplastin analysis, Brain Ischemia blood, Brain Ischemia diagnosis, Cell-Derived Microparticles pathology, Ischemic Attack, Transient blood, Ischemic Attack, Transient diagnosis, Ischemic Stroke blood, Ischemic Stroke diagnosis
- Abstract
Platelet 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 with reduced risk of poor long-term outcome. Our results suggest that PS+ TF+ PMV may be a promising marker for cerebral ischemia, and that the in vivo generation of PS- MV after IS/TIA warrants further study. Future MV studies should ideally enumerate PS+ and PS- MV subpopulations separately.- Published
- 2020
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