title: Increased circulating endothelial microparticles in COPD patients: a potential biomarker for COPD exacerbation susceptibility.
abstract: BACKGROUND
  The influence of COPD exacerbation on the endothelium is not completely understood. Circulating endothelial microparticles (EMPs) are membrane vesicles in circulating blood that are shed by activated or apoptotic endothelial cells.
  
  
  OBJECTIVE
  To compare EMP numbers in stable COPD patients with those during and after exacerbation.
  
  
  METHODS
  We examined the EMP numbers in 80 stable COPD patients, 27 patients with exacerbated COPD, and 20 healthy non-COPD volunteers. EMPs were defined as CD144+ MPs (VE-cadherin EMPs), CD31+/CD41- MPs (PECAM EMPs), CD146 MPs (MCAM EMPs) and CD62E+ EMPs (E-selectin EMPs) as analysed by FACS. Von Willebrand factor (vWF) expression was utilised to identify the origins of the EMPs.
  
  
  RESULTS
  VE-cadherin, PECAM and E-selectin EMP numbers were significantly higher in the stable COPD patients than in the non-COPD volunteers, and they were significantly higher in the patients with exacerbated COPD than in the stable COPD patients. The majority of these increased EMPs were vWF-negative, indicating a pulmonary capillary origin. Baseline E-selectin EMP levels were significantly higher in COPD patients who experienced frequent exacerbations than in those who did not have frequent exacerbations (p<0.001). Twenty-eight days after the onset of exacerbation, E-selectin EMP levels returned to those observed in stable COPD patients, whereas PECAM EMP levels remained high. MCAM EMP numbers were not elevated in stable or exacerbated-COPD patients.
  
  
  CONCLUSIONS
  Endothelial damage, mainly in pulmonary capillaries, occurs during exacerbation and continues even after clinical symptoms disappear. Higher baseline E-selectin EMP levels may indicate COPD patients who are susceptible to exacerbation.
authors: Department of Advanced Preventive Medicine for Infectious Disease, Tohoku University Graduate School of Medicine, 2-1 Seiryoumachi, Aobaku, Sendai 980-8575, Japan.
authors: Toru
authors: T
authors: Takahashi
authors: Seiichi
authors: S
authors: Kobayashi
authors: Naoya
authors: N
authors: Fujino
authors: Takaya
authors: T
authors: Suzuki
authors: Chiharu
authors: C
authors: Ota
authors: Mei
authors: M
authors: He
authors: Mitsuhiro
authors: M
authors: Yamada
authors: Satoshi
authors: S
authors: Suzuki
authors: Masaru
authors: M
authors: Yanai
authors: Shin
authors: S
authors: Kurosawa
authors: Mutsuo
authors: M
authors: Yamaya
authors: Hiroshi
authors: H
authors: Kubo
mesh_terms: D000368:Aged; D015703:Antigens, CD / Q000097:blood; D015415:Biomarkers / Q000097:blood*; D051929:CD146 Antigen / Q000097:blood; D015820:Cadherins / Q000097:blood; D016022:Case-Control Studies; D055252:Cell-Derived Microparticles; D016009:Chi-Square Distribution; D019040:E-Selectin / Q000097:blood; D004730:Endothelium, Vascular / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000097:blood; D040201:Platelet Membrane Glycoprotein IIb / Q000097:blood; D029424:Pulmonary Disease, Chronic Obstructive / Q000097:blood* / Q000503:physiopathology*; D012044:Regression Analysis; D012129:Respiratory Function Tests; D012307:Risk Factors; D018709:Statistics, Nonparametric; D014841:von Willebrand Factor / Q000378:metabolism; D000099152:Cadherin 5
chemical_list: D015703:Antigens, CD; D015415:Biomarkers; D051929:CD146 Antigen; D015820:Cadherins; D019040:E-Selectin; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D040201:Platelet Membrane Glycoprotein IIb; D014841:von Willebrand Factor; D000099152:Cadherin 5