Thrombocytes are the major source for soluble vascular endothelial growth factor in peripheral blood
Oncology, 58 (2):
169-174 (2000)Abstract
Serum levels of vascular endothelial growth factor (VEGF-S) have been reported to correlate with tumor stage and prognosis in various human malignancies. The source of soluble VEGF in peripheral blood remains obscure. We therefore measured the concentration of immunoreactive VEGF in 241 serum samples and 61 plasma samples (VEGF-P) from 20 subjects undergoing myeloablative chemotherapy and from 3 normal platelet donors. A significant correlation between the peripheral blood platelet count (PC) and VEGF-S (r = 0.86) but not VEGF-P was found. VEGF-S levels were 58.43 +/- 42.50 pg/ml (mean +/- SD) in patients with a PC < 50 x 10(9)/l, 203.29 +/- 176.56 pg/ml for a PC of 50-150 x 10(9)/l, and 457.42 +/- 475.41 pg/ml for a PC > 150 x 10(9)/l. Interestingly, VEGF-P levels were substantially lower than the corresponding VEGF-S values, namely below the detection limit in most cases. Supernatants from platelet-rich plasma contained no VEGF, but after in vitro lysis of the platelets very high VEG