The Role of the P2Y12 Receptor in Tissue Factor Induced Coagulation

Severe sepsis still carries a high mortality rate despite advantages in intensive care medicine and antimicrobial therapy. The inflammatory and procoagulant host response to infection are intricately linked and interactions between platelets, leukocytes and the endothelium play a central role in the pathogenesis of septic shock and disseminated intravascular coagulation (DIC). Interestingly, one key player cell in coagulation, i.e. the platelet, has been somewhat neglected as to its position in the pathogenesis of coagulation abnormalities in sepsis. However, thienopyridines, irreversible platelet P2Y12 ADP-receptor antagonists, e.g. prasugrel, could potentially provide beneficial anticoagulatory and antiinflammatory effects: P2Y12 ADP-receptor antagonists reduce TF-induced coagulation activation in various ex vivo and in vitro models. Moreover, various lines of evidence indicate that thienopyridines may block platelet leukocyte interactions and thereby reduce the propagation of the coagulation and inflammation process. LPS-infusion in healthy volunteers provides a standardized model to safely study non overt DIC and to document possible effects of therapeutic and prophylactic interventions. The investigators hypothesize that thienopyridines, irreversible platelet P2Y12 ADP-receptor antagonists, may blunt TF-triggered coagulation activation in humans, which will be studied in a TF-dependent coagulation model in humans.