Conflict of interest: Nothing to report.
Normal ranges of angiogenesis regulatory proteins in human platelets†
Version of Record online: 13 APR 2010
Copyright © 2010 Wiley-Liss, Inc.
American Journal of Hematology
Volume 85, Issue 7, pages 487–493, July 2010
How to Cite
Peterson, J. E., Zurakowski, D., Italiano, J. E., Michel, L. V., Fox, L., Klement, G. L. and Folkman, J. (2010), Normal ranges of angiogenesis regulatory proteins in human platelets. Am. J. Hematol., 85: 487–493. doi: 10.1002/ajh.21732
- Issue online: 23 JUN 2010
- Version of Record online: 13 APR 2010
- Manuscript Accepted: 6 APR 2010
- Manuscript Received: 23 JAN 2010
- Ortho Clinical Diagnostics
Platelets sequester angiogenesis regulatory proteins early in tumor growth, which suggests a new avenue for monitoring disease. To date, there are no clinically relevant reference ranges for markers of early angiogenesis. We introduce a new ELISA-based method for accurate and reproducible measurement of vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), platelet factor 4 (PF4), thrombospondin-1 (TSP-1), fibroblast growth factor, basic (bFGF), and endostatin in platelets. To facilitate clinical applicability, the platelet levels in isolated samples were determined utilizing a new actin ELISA method. Platelets from healthy donors at single and repetitive time points were used for the assessment of normal ranges of these proteins. The physiological levels in platelets were: VEGF (0.74 ± 0.37 pg/106 platelets); PDGF (23 ± 6 pg/106); PF4 (12 ± 5 ng/106); TSP-1 (31 ± 12 ng/106); bFGF (0.44 ± 0.15 pg/106); and endostatin (5.6 ± 3.0 pg/106). There was an excellent correlation (R2 = 0.7) between the platelet levels calculated with the actin ELISA and complete blood count. The levels of the platelets were higher than those in platelet-poor plasma by factors of: VEGF (215-fold); PDGF (914-fold); PF-4 (516-fold); TSP-1 (813-fold); and bFGF (17-fold). The endostatin levels were nearly equivalent. The biovariability of the platelet proteins in eight healthy subjects over a 5-week period was found to be minimal. We describe accurate and direct measurements of the concentrations of VEGF, bFGF, PDGF, TSP-1, endostatin, and PF4 in platelets of healthy human subjects. In contrast to the highly variable levels in plasma and serum, the platelet-derived measurements were accurate and reproducible with minimal biovariability. Am. J. Hematol., 2010. © 2010 Wiley-Liss, Inc.