title: Circulating platelet-derived microparticles and endothelium-derived microparticles may be a potential cause of microthrombosis in patients with osteonecrosis of the femoral head.
abstract: BACKGROUND
  To test the hypothesis that the platelet microparticle (PMP) and endothelial microparticle (EMP) may contribute to the hypercoagulability associated with microvascular thrombosis in patients with nontraumatc osteonecrosis of the femoral head (ONFH).
  
  
  METHODS
  The study comprised 46 patients who had been diagnosed with ONFH and 20 control subjects. The plasma was ultracentrifuged, and then PMPs and EMPs were examined by the flow cytometry. The thrombotic and fibrinolytic disorders were investigated.
  
  
  RESULTS
  The numbers of PMPs expressing P-selectin and CD42a and EMPs expressing E-selectin and CD31 in the ONFH patients were significantly higher than those in the controls (P<0.001). The number of MPs was correlated with the level of the serum C-reactive protein (CRP) (r=0.661, P<0.001), but there was a poor correlation between the MPs counts and the risk factors for ONFH (P>0.05). The mean levels PAI-1, F1+2, and TAT were higher in the patients with ONFH than in the controls (P<0.05).
  
  
  CONCLUSIONS
  The elevated numbers of PMPs and EMPs may contribute to hypercoagulability in the ONFH patients. This may provide important pathophysiological insights into the hypercoagulability associated with nontraumatic ONFH and have implications for pharmacological prevention and treatment of ONFH.
authors.affiliation: Orthopaedic Department, West China Hospital, Sichuan University, Chengdu (610041), People's Republic of China.
authors.forename: Pengde
authors.initials: P
authors.lastname: Kang
authors.forename: Bin
authors.initials: B
authors.lastname: Shen
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.forename: Fuxing
authors.initials: F
authors.lastname: Pei
mesh_terms: D000328:Adult; D001792:Blood Platelets / Q000378:metabolism / Q000473:pathology*; D002097:C-Reactive Protein / Q000378:metabolism; D016022:Case-Control Studies; D019040:E-Selectin / Q000097:blood; D042783:Endothelial Cells / Q000378:metabolism / Q000473:pathology*; D005260:Female; D005271:Femur Head Necrosis / Q000097:blood / Q000139:chemically induced / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D019007:P-Selectin / Q000097:blood; D010316:Particle Size; D010976:Platelet Count; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000378:metabolism; D012307:Risk Factors; D013927:Thrombosis / Q000209:etiology*
chemical_list: D019040:E-Selectin; D019007:P-Selectin; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D019038:Platelet Glycoprotein GPIb-IX Complex; D002097:C-Reactive Protein