title: Temporal and venepuncture-related decline in circulating endothelial cell capture from mixed venous blood.
abstract: BACKGROUND
  The quantification of circulating endothelial cells (CECs) in whole blood has evolved as a novel method for the assessment of endothelial function, although major methodological issues remain. We hypothesized that there is a temporal decline in CEC counts in static venesected blood and that venepuncture itself may lead to increased CEC detachment.
  
  
  METHODS
  CEC isolation was performed using the immunobead method. For the temporal decline experiment, we included 52 patients presenting with acute coronary syndrome (ACS). We performed CEC counts immediately and at 4 and 24 h later. For the venepuncture decline experiment, we studied 40 patients with stable cardiovascular disease (CVD). CEC counts were determined from the first 4 mL of aspirated venous blood and compared with counts obtained from a subsequent 4 mL sample of blood after at least 7.5 mL of blood had been collected.
  
  
  RESULTS
  Among the ACS patients there was a significant temporal decline in CEC counts in static venous blood over a 24 h period (p = 0.013). Among the patients with stable CVD, the median CEC counts obtained from the initial 4 mL of aspirated venous blood were significantly higher (by 32%) than that obtained from the later 4 mL of aspirated venous blood (p = 0.041).
  
  
  CONCLUSIONS
  We demonstrated a significant temporal fall in CEC numbers in static venous blood over 24 h following venesection. Furthermore, we have shown that CEC counts are higher in the initial aspirated blood compared with that aspirated from the same needle subsequently. These data would have implications for how CEC determination is undertaken by researchers in studies related to ACS or CVD.
authors.affiliation: Haemostasis, Thrombosis and Vascular Biology Unit, University Department of Medicine, City Hospital, Birmingham, UK, B18 7QH.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Boos
authors.forename: Deirdre A
authors.initials: DA
authors.lastname: Lane
authors.forename: Delene
authors.initials: D
authors.lastname: Kang
authors.forename: Patrick K Y
authors.initials: PK
authors.lastname: Goon
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Blann
authors.forename: Gregory Y H
authors.initials: GY
authors.lastname: Lip
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000789:Angina, Unstable / Q000097:blood*; D002318:Cardiovascular Diseases / Q000097:blood*; D002452:Cell Count / Q000379:methods; D042783:Endothelial Cells; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000097:blood*