title: Expression of EMMPRIN (CD147) on circulating platelets in vivo.
abstract: OBJECTIVE
  EMMPRIN (CD147) is a matrix metalloproteinase inducer present on leukocytes and recently identified on platelets in vitro. We examined platelet CD147 expression in vivo and in correlation with markers of platelet activation and coronary artery disease (CAD).
  
  
  METHODS
  This prospective observational study involved 70 subjects (55 patients with CAD and 15 controls). Platelet CD62P expression, PAC-1 expression, platelet-leukocyte aggregates and CD147 (both platelet and leukocyte) expression were assessed by flow cytometry, and soluble CD62P expression was assessed by enzyme-linked immunosorbent assay. A full blood count and high-sensitivity C-reactive protein test were performed.
  
  
  RESULTS
  CD147 was expressed on 20.45% +/- 1.63% (mean +/- standard error of the mean) of circulating platelets, whereas CD62P and PAC-1 were expressed on 0.87% +/- 0.12% and 0.90% +/- 0.27% of platelets, respectively. Platelet CD147 expression correlated with CD62P expression (r = 0.359, P = 0.002), PAC-1 expression (r = 0.428, P < 0.001), leukocyte CD147 expression (monocyte, r = 0.416, P = 0.001; granulocyte, r = 0.434, P < 0.001), C-reactive protein level and neutrophil/lymphocyte ratio (NLR). CAD patients had significantly higher CD147 mean fluorescence intensity than controls on circulating platelets (2.41 +/- 0.14 vs. 2.87 +/- 0.09, P = 0.014), monocytes (8.57 +/- 1.20 vs. 12.3 +/- 0.57, P = 0.006) and granulocytes (4.30 +/- 0.65 vs. 6.50 +/- 0.34, P = 0.005). Age adjustment eliminated the association between platelet CD147 expression and CAD, but the association between leukocyte CD147 expression and CAD persisted. According to multivariate analysis, the independent predictors of platelet CD147 expression were monocyte CD147 expression, NLR and age.
  
  
  CONCLUSIONS
  Platelet CD147 expression is evident in vivo and correlates moderately with traditional platelet activation markers and leukocyte CD147 expression. Platelet CD147 expression shows a stronger association with age, and leukocyte CD147 expression a stronger association with clinical CAD, suggesting differences in the regulation of platelet and leukocyte CD147 expression in vivo.
authors.affiliation: Vascular Biology Group, ANZAC Research Institute, New South Wales, Australia.
authors.forename: G J
authors.initials: GJ
authors.lastname: Pennings
authors.forename: A S C
authors.initials: AS
authors.lastname: Yong
authors.forename: L
authors.initials: L
authors.lastname: Kritharides
mesh_terms: D000367:Age Factors; D000368:Aged; D051926:Basigin / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D001792:Blood Platelets / Q000276:immunology*; D002097:C-Reactive Protein / Q000032:analysis; D016022:Case-Control Studies; D003324:Coronary Artery Disease / Q000097:blood / Q000276:immunology*; D054641:Dual Specificity Phosphatase 2 / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007962:Leukocytes / Q000276:immunology; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D019007:P-Selectin / Q000097:blood; D015539:Platelet Activation; D011446:Prospective Studies
chemical_list: C497886:BSG protein, human; D015415:Biomarkers; D019007:P-Selectin; D051926:Basigin; D002097:C-Reactive Protein; C517032:DUSP2 protein, human; D054641:Dual Specificity Phosphatase 2