title: Increased platelet activation in patients with stable and acute exacerbation of COPD.
abstract: BACKGROUND
  Chronic obstructive pulmonary disease (COPD) is associated with systemic inflammation and cardiovascular disease. Interaction between inflammatory cells and activated platelets is important in the pathogenesis of atherothrombosis and may contribute to cardiovascular risk in patients with COPD.
  
  
  OBJECTIVE
  To assess platelet-monocyte aggregation in patients with COPD and matched controls, and in patients with an acute exacerbation of COPD.
  
  
  METHODS
  18 men with COPD and 16 male controls matched for age and cigarette smoke exposure were recruited. A further 12 patients were investigated during and at least 2 weeks after hospitalisation for an acute exacerbation. Platelet-monocyte aggregation and platelet P-selectin expression were determined using flow cytometry.
  
  
  RESULTS
  Patients with COPD had increased circulating platelet-monocyte aggregates compared with controls (mean (SD) 25.3 (8.3)% vs 19.5 (4.0)%, p=0.01). Platelet-monocyte aggregation was further increased during an acute exacerbation compared with convalescence (32.0 (11.0)% vs 25.5 (6.4)%, p=0.03). Platelet P-selectin expression and soluble P-selectin did not differ between groups.
  
  
  CONCLUSIONS
  Patients with stable COPD have increased circulating platelet-monocyte aggregates compared with well-matched controls. Platelet activation is further increased in patients with COPD during an acute exacerbation. These findings identify a novel mechanism to explain the increased cardiovascular risk in COPD and suggest platelet inhibition as a plausible therapeutic target.
authors.affiliation: ELEGI/Colt Laboratories, Centre for Inflammation Research, Edinburgh University, Edinburgh, UK.
authors.forename: John D
authors.initials: JD
authors.lastname: Maclay
authors.forename: David A
authors.initials: DA
authors.lastname: McAllister
authors.forename: Shonna
authors.initials: S
authors.lastname: Johnston
authors.forename: Jennifer
authors.initials: J
authors.lastname: Raftis
authors.forename: Catherine
authors.initials: C
authors.lastname: McGuinnes
authors.forename: Andrew
authors.initials: A
authors.lastname: Deans
authors.forename: David E
authors.initials: DE
authors.lastname: Newby
authors.forename: Nicholas L
authors.initials: NL
authors.lastname: Mills
authors.forename: William
authors.initials: W
authors.lastname: MacNee
mesh_terms: D001792:Blood Platelets / Q000502:physiology*; D018450:Disease Progression; D005260:Female; D005434:Flow Cytometry; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D019007:P-Selectin / Q000096:biosynthesis; D015539:Platelet Activation / Q000502:physiology*; D011379:Prognosis; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000503:physiopathology; D012008:Recurrence
chemical_list: D019007:P-Selectin