title: Microparticles and blood cells induce procoagulant activity via phosphatidylserine exposure in NSTEMI patients following stent implantation.
abstract: BACKGROUND
  Relatively little is known about the role of phosphatidylserine (PS) in procoagulant activity (PCA) in patients with non-ST-elevated myocardial infarction (NSTEMI) after stent implantation. This study was designed to evaluate whether exposed PS on microparticles (MPs) and blood cells were involved in the hypercoagulable state in NSTEMI patients with stent implantation.
  
  
  METHODS
  NSTEMI patients (n=90) and healthy controls (n=20) were included in our study. PS exposure on MPs and blood cells was analyzed with flow cytometer and confocal microscope. PCA was evaluated by clotting time, purified coagulation complex assays and fibrin production assays.
  
  
  RESULTS
  Baseline levels of MPs and PS+blood cells were significantly higher (P<0.001) in the patients than in controls. After stent implantation, a remarkable increase was observed in both MPs and PS+blood cells. Specifically, PS+MPs, PS+platelets and erythrocytes peaked at 18h following stent implantation, while PS+leukocytes peaked on day 2. In addition, circulating MPs (mostly derived from platelets, leukocytes, erythrocytes and endothelial cells) cooperating with PS+blood cells, contributed to markedly shortened coagulation time and markedly increased FXa/thrombin/fibrin (all P<0.01) generation in patient group. Moreover, blockade of exposed PS on MPs and cells with lactadherin inhibited PCA by approximately 70%.
  
  
  CONCLUSIONS
  Our results suggest that PS+MPs and blood cells play a procoagulant role in NSTEMI patients following stent implantation. Blockade of PS could become a novel therapeutic modality for the prevention of thrombosis in these patients.
authors.affiliation: Department of Cardiology, The First Hospital, Harbin Medical University, Harbin, China.
authors.forename: Lixiu
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Cardiology, The First Hospital, Harbin Medical University, Harbin, China. Electronic address: biyayan@163.com.
authors.forename: Yayan
authors.initials: Y
authors.lastname: Bi
authors.affiliation: Department of Hematology, The First Hospital, Harbin Medical University, Harbin, China.
authors.forename: Muhua
authors.initials: M
authors.lastname: Cao
authors.affiliation: Department of Hematology, The First Hospital, Harbin Medical University, Harbin, China.
authors.forename: Ruishuang
authors.initials: R
authors.lastname: Ma
authors.affiliation: Department of Hematology, The First Hospital, Harbin Medical University, Harbin, China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Wu
authors.affiliation: Department of Hematology, The First Hospital, Harbin Medical University, Harbin, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Cardiology, The Second Hospital, Harbin Medical University, Harbin, China.
authors.forename: Wenbo
authors.initials: W
authors.lastname: Ding
authors.affiliation: Department of Hematology, The First Hospital, Harbin Medical University, Harbin, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Cardiology, The First Hospital, Harbin Medical University, Harbin, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Yu
authors.affiliation: Department of Cardiology, The Second Hospital, Harbin Medical University, Harbin, China.
authors.forename: Yingqian
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Cardiology, The Second Hospital, Harbin Medical University, Harbin, China.
authors.forename: Hua
authors.initials: H
authors.lastname: Jiang
authors.affiliation: Department of Nephropathy, The First Hospital, Harbin Medical University, Harbin, China.
authors.forename: Yingchun
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Department of Hematology, The First Hospital, Harbin Medical University, Harbin, China.
authors.forename: Dongxia
authors.initials: D
authors.lastname: Tong
authors.affiliation: Department of Hematology, The First Hospital, Harbin Medical University, Harbin, China.
authors.forename: Li
authors.initials: L
authors.lastname: Guo
authors.affiliation: Department of Cardiology, The First Hospital, Harbin Medical University, Harbin, China.
authors.forename: Zengxiang
authors.initials: Z
authors.lastname: Dong
authors.affiliation: Department of Cardiology, The First Hospital, Harbin Medical University, Harbin, China.
authors.forename: Ye
authors.initials: Y
authors.lastname: Tian
authors.affiliation: Department of Cardiology, The Second Hospital, Harbin Medical University, Harbin, China. Electronic address: junjiekou@163.com.
authors.forename: Junjie
authors.initials: J
authors.lastname: Kou
authors.affiliation: Department of Hematology, The First Hospital, Harbin Medical University, Harbin, China; Cardiothoracic Surgery Division, Brigham and Women's Hospital, VA Boston Healthcare System, Harvard Medical School, Boston, MA, USA. Electronic address: jialan_shi73661@gmail.com.
authors.forename: Jialan
authors.initials: J
authors.lastname: Shi
mesh_terms: D000368:Aged; D001241:Aspirin / Q000627:therapeutic use; D001773:Blood Cells / Q000378:metabolism / Q000473:pathology; D001777:Blood Coagulation / Q000502:physiology; D055252:Cell-Derived Microparticles / Q000378:metabolism*; D000077144:Clopidogrel; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D000072658:Non-ST Elevated Myocardial Infarction / Q000097:blood / Q000150:complications / Q000188:drug therapy / Q000601:surgery; D062645:Percutaneous Coronary Intervention / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods; D010718:Phosphatidylserines / Q000032:analysis*; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D013223:Statistics as Topic; D015607:Stents; D019851:Thrombophilia / Q000209:etiology / Q000378:metabolism; D013988:Ticlopidine / Q000031:analogs & derivatives / Q000627:therapeutic use
chemical_list: D010718:Phosphatidylserines; D010975:Platelet Aggregation Inhibitors; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin
keywords: Microparticles; Non-ST-elevated myocardial infarction; Phosphatidylserine; Procoagulant activity; Stent