title: Platelet monocyte aggregates and monocyte chemoattractant protein-1 are not inhibited by aspirin in critical limb ischaemia.
abstract: OBJECTIVE
  Platelet monocyte aggregates (PMA) and monocyte chemoattractant protein-1 (MCP-1) play a significant role in atherosclerotic disease but the effect of aspirin and their role in peripheral arterial disease (PAD) requires further investigation. We have compared p-selectin, PMA and MCP-1 in patients with PAD treated with aspirin (75 mgs daily), with age matched controls not treated with aspirin.
  
  
  METHODS
  Using flow cytometry and ELISA, P-selectin, PMA and MCP-1 were compared in 3 populations; healthy controls (n=12), intermittent claudication (n=19) and critical limb ischaemia (CLI), (n=10).
  
  
  RESULTS
  P-selectin was significantly higher in CLI patients (3.48% positive) compared to the claudicants (1. 36% positive) and the controls (1.76% positive). PMA levels were significantly higher for CLI population (44.5% positive) compared to the claudicants (20.48% positive) and the controls (28.33% positive). MCP-1 levels expression was significantly higher for the CLI patients (175.4 pg/mL) compared to the claudicants (76.1 pg/mL) and the controls (117.0 pg/mL).
  
  
  CONCLUSIONS
  Despite aspirin treatment CLI patients have higher platelet activation and MCP-1 expression than controls and claudicants. With increasing severity of disease aspirin is unable to suppress markers of platelet activation and pro-atherosclerotic chemokine expression which may represent another form of aspirin resistance.
authors.affiliation: Queen Elizabeth Hospital, Vascular Surgery Department, Gateshead, UK.
authors.forename: M
authors.initials: M
authors.lastname: Cleanthis
authors.forename: V
authors.initials: V
authors.lastname: Bhattacharya
authors.forename: J
authors.initials: J
authors.lastname: Smout
authors.forename: H
authors.initials: H
authors.lastname: Ashour
authors.forename: G
authors.initials: G
authors.lastname: Stansby
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography; D001241:Aspirin / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D018932:Chemokine CCL2 / Q000097:blood / Q000187:drug effects*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007511:Ischemia / Q000097:blood* / Q000175:diagnosis / Q000188:drug therapy; D007866:Leg / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D019007:P-Selectin / Q000097:blood / Q000187:drug effects; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D012307:Risk Factors; D012720:Severity of Illness Index; D016896:Treatment Outcome; D018616:Ultrasonography, Doppler, Duplex
chemical_list: D015415:Biomarkers; D018932:Chemokine CCL2; D019007:P-Selectin; D010975:Platelet Aggregation Inhibitors; D001241:Aspirin