Affiliations: Department of Surgery, General Hospital, Medical
University of Vienna, Vienna, Austria
Note: [] Corresponding author: Christine Brostjan, Department of
Surgery, Medical University of Vienna, Anna Spiegel Research Laboratories,
General Hospital AKH 25.05.002, Waehringer Guertel 18-20, A-1090 Vienna,
Austria. Tel.: +43 1 40400 73514; Fax: +43 1 40400 6782; E-mail:
christine.brostjan@meduniwien.ac.at
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). Conclusion: 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.
