title: Platelet-stored angiogenesis factors: clinical monitoring is prone to artifacts.
abstract: BACKGROUND
  The analysis of angiogenesis factors in the blood of tumor patients has given diverse results on their prognostic or predictive value. Since mediators of angiogenesis are stored in platelets, their measurement in plasma is sensitive to inadvertent platelet activation during blood processing.
  
  
  METHODS
  Variants of blood withdrawal and plasma preparation were evaluated by ELISA for the detection of TSP-1, PF-4, VEGF and PD-ECGF. A total of 22 pancreatic cancer patients and 29 healthy volunteers were evaluated.
  
  
  RESULTS
  Plasma preparation with the anticoagulant mix of citrate, theophylline, adenosine, dipyridamole (CTAD) and immediate blood processing at 4°C was required for reproducible measurements of TSP-1, PF-4 and VEGF. Blood collection by venflon or inadvertent hemolysis during blood withdrawal caused significantly elevated TSP-1 and PF-4 values. When optimized plasma preparation was applied, a significant increase of TSP-1 and VEGF in cancer patients was detected (P=0.006; P< 0.001).
  
  
  CONCLUSIONS
  The reliable plasma analysis of circulating platelet-stored angiogenesis factors requires preparation with CTAD at 4°C and blood collection by butterfly needle. Suboptimal procedures of plasma preparation are commonly applied in clinical monitoring of angiogenesis parameters which may account for the differences in reported plasma values and may have masked their predictive or prognostic marker potential.
authors: Department of Surgery, General Hospital, Medical University of Vienna, Austria.
authors: Patrick
authors: P
authors: Starlinger
authors: Lejla
authors: L
authors: Alidzanovic
authors: Dominic
authors: D
authors: Schauer
authors: Philipp
authors: P
authors: Brugger
authors: Silvia
authors: S
authors: Sommerfeldt
authors: Irene
authors: I
authors: Kuehrer
authors: Sebastian F
authors: SF
authors: Schoppmann
authors: Michael
authors: M
authors: Gnant
authors: Christine
authors: C
authors: Brostjan
mesh_terms: D000241:Adenosine / Q000737:chemistry; D000328:Adult; D000368:Aged; D053000:Analytic Sample Preparation Methods / Q000592:standards*; D042501:Angiogenic Proteins / Q000097:blood*; D016477:Artifacts; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000097:blood; D001792:Blood Platelets / Q000737:chemistry*; D019343:Citric Acid / Q000737:chemistry; D004176:Dipyridamole / Q000737:chemistry; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D009389:Neovascularization, Pathologic / Q000097:blood* / Q000175:diagnosis; D010949:Plasma / Q000737:chemistry*; D010978:Platelet Factor 4 / Q000097:blood; D013806:Theophylline / Q000737:chemistry; D013939:Thymidine Phosphorylase / Q000097:blood; D042461:Vascular Endothelial Growth Factor A / Q000097:blood
chemical_list: D042501:Angiogenic Proteins; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; C481348:SPZ1 protein, human; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D019343:Citric Acid; D010978:Platelet Factor 4; D004176:Dipyridamole; D013806:Theophylline; C543750:TYMP protein, human; D013939:Thymidine Phosphorylase; D000241:Adenosine