title: Dissimilarity of increased phosphatidylserine-positive microparticles and associated coagulation activation in acute coronary syndromes.
abstract: OBJECTIVE
  We evaluated cellular origin, numbers, and procoagulant activity of phosphatidylserine-positive microparticles (MPs) among subgroups in acute coronary syndromes (ACS).
  
  
  METHODS
  Parameters were measured on admission, days 1 (within 24 h of admission), 2, 3, and 7. All ST-elevated myocardial infarction (STEMI) patients presented more than 3 h from symptom onset and received fibrinolysis treatment; controls included unstable angina and non-STEMI patients as well as healthy controls. Phosphatidylserine-positive MPs were detected by flow cytometry, whereas procoagulant activity was assessed by coagulation time, purified coagulation complex assays, and fibrin formation. MP-induced fibrins were visualized by confocal microscopy.
  
  
  RESULTS
  On admission, the total MP count was ∼2.5-fold higher in the ACS groups compared with the healthy controls (P<0.05), primarily originating from platelets and endothelial cells, and there were no significant differences among ACS subgroups. Specifically, leukocyte-derived and erythrocyte-derived MPs were higher in the STEMI group compared with unstable angina and non-STEMI groups (both P<0.05). Further, MPs from the ACS groups reduced coagulation time by 27.5% and induced intrinsic and extrinsic FXase, prothrombinase, and fibrin formation by 2.8-, 2.3-, 2.5-, and 1.7-fold, respectively (P<0.05 for all), whereas blocking phosphatidylserine with lactadherin inhibited ∼70% of procoagulant activity. MP number and concomitant coagulation decreased significantly by day 2 and continued to decrease gradually during the recovery period.
  
  
  CONCLUSIONS
  This study shows that MP characteristics from circulating blood may be used as prognostic indicators to reflect the origin cell of activation and thrombophilic states found in ACS subgroups.
authors.affiliation: Departments of aHematology bCardiology, The First Hospital cDepartment of Cardiology, The Second Hospital, Harbin Medical University, Harbin, People's Republic of China dDepartment of Surgery, Brigham and Women's Hospital, VA Boston Healthcare System, Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.forename: Zhangxiu
authors.initials: Z
authors.lastname: He
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Zengxiang
authors.initials: Z
authors.lastname: Dong
authors.forename: Yayan
authors.initials: Y
authors.lastname: Bi
authors.forename: Junjie
authors.initials: J
authors.lastname: Kou
authors.forename: Jin
authors.initials: J
authors.lastname: Zhou
authors.forename: Jialan
authors.initials: J
authors.lastname: Shi
mesh_terms: D054058:Acute Coronary Syndrome / Q000097:blood* / Q000175:diagnosis / Q000188:drug therapy; D000328:Adult; D000368:Aged; D000789:Angina, Unstable / Q000097:blood* / Q000175:diagnosis / Q000188:drug therapy; D015415:Biomarkers / Q000097:blood; D001777:Blood Coagulation / Q000187:drug effects; D001780:Blood Coagulation Tests; D016022:Case-Control Studies; D055252:Cell-Derived Microparticles / Q000378:metabolism*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D000072658:Non-ST Elevated Myocardial Infarction / Q000097:blood* / Q000175:diagnosis / Q000188:drug therapy; D010718:Phosphatidylserines / Q000097:blood*; D011237:Predictive Value of Tests; D000072657:ST Elevation Myocardial Infarction / Q000097:blood* / Q000175:diagnosis / Q000188:drug therapy; D015912:Thrombolytic Therapy; D013997:Time Factors; D061665:Time-to-Treatment
chemical_list: D015415:Biomarkers; D010718:Phosphatidylserines