| |
|
|
|
|
|
|
|||
|
Blood, 15 September 2007, Vol. 110, No. 6, pp. 1903-1905. Prepublished online as a Blood First Edition Paper on May 31, 2007; DOI 10.1182/blood-2007-03-081901.
HEMOSTASIS, THROMBOSIS, AND VASCULAR BIOLOGY Endogenous platelet factor 4 stimulates activated protein C generation in vivo and improves survival after thrombin or lipopolysaccharide challenge1 Division of Hematology, The Children's Hospital of Philadelphia, PA; 2 Center for Medical Biology, Polish Academy of Science, Lodz, Poland; 3 Department of Hematology, Oncology and Transplantation Medicine, University of Minnesota, Minneapolis; and 4 Department of Pediatrics, University of Pennsylvania School of Medicine, Philadelphia Pharmacologic infusion of activated protein C (APC) improves survival in severe sepsis, and platelet factor 4 (PF4) accelerates APC generation in a primate thrombin-infusion model. We now tested whether endogenous platelet PF4 content affects APC generation. Mice completely deficient in PF4 (mPF4–/–) had impaired APC generation and survival after thrombin infusion, similar to the impairment seen in heterozygote protein C–deficient (PC+/–) mice. Transgenic mice overexpressing human PF4 (hPF4+) had increased plasma APC generation. Overexpression of platelet PF4 compensated for the defect seen in PC+/– mice. In both a thrombin and a lipopolysaccharide (LPS) survival model, hPF4+ and PC+/–/hPF4+ mice had improved survival. Further, infusion of hPF4+ platelets improved survival of wild-type mice after an LPS challenge. These studies suggest that endogenous PF4 release may have biologic consequences for APC generation and survival in clinical sepsis. Infusions of PF4-rich platelets may be an effective strategy to improve outcome in this setting.
This article has been cited by other articles:
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Copyright © 2007 by American Society of Hematology Online ISSN: 1528-0020 | |||||||||