Potent irreversible P2Y12 inhibition does not reduce LPS-induced coagulation activation in a randomized, double-blind, placebo-controlled trial

Abstract

Platelets play an important role in the activation of coagulation. P2Y12 receptor inhibition may be beneficial in inflammatory states. Prasugrel, a potent irreversible inhibitor of P2Y12 receptor-induced platelet activation may reduce activation of coagulation in a human LPS (lipopolysaccharide) model. A double-blind, randomized, crossover trial with a minimum washout period of 6 weeks was performed. Sixteen subjects were randomly assigned to a treatment group that received prasugrel or placebo 2 h before infusion of a bolus of LPS (2 ng/kg of body weight), whereas four subjects were assigned to a control group receiving prasugrel or placebo without LPS. hcDNA (histone-complexed DNA), coagulation and platelet-specific parameters were measured by enzyme immunoassay. Leucocyte aggregate formation was analysed by flow cytometry, and thromboelastometry was performed. LPS infusion markedly activated coagulation. However, prasugrel did not reduce changes in prothrombin fragments 1 and 2 (F1+2), thrombin-antithrombin complexes, microparticle-associated tissue factor, CD40 ligand, P-selectin, platelet-leucocyte aggregation, hcDNA levels or the coagulation profile measured by thromboelastometry. hcDNA plasma levels increased approximately 6-fold after LPS infusion in both treatment groups, but not in the control groups. Potent irreversible P2Y12 inhibition by prasugrel does not affect LPS-induced coagulation activation. The 6-fold increased hcDNA plasma levels after infusion of LPS indicates the formation of neutrophil extracellular traps during sterile inflammation.

Histones link inflammation and thrombosis through the induction of Weibel–Palade body exocytosis

“…Sepsis is an acute reaction to a systemic pathogenic microorganism insult, resulting in uncontrolled activation of inflammation, with concomitant activation of the coagulation system, resulting in pathologic immunothrombosis . Previous reports have demonstrated that VWF , CF‐DNA and nucleosome levels are elevated in patients with severe sepsis and in human LPS trials . We further demonstrated that, in both septic patients and a murine model of endotoxemia, plasma levels of WPB‐released proteins and CF‐DNA were elevated; however, no correlation was observed (Fig.…”

Circulating MicroRNA Levels Indicate Platelet and Leukocyte Activation in Endotoxemia Despite Platelet P2Y12 Inhibition

“…Platelet-monocyte aggregates are known to amplify monocyte release of proinflammatory cytokines that are responsible for the excessive immune response in sepsis, and their prevention could therefore be beneficial [50,51]. Consistent with the absent response of platelet-neutrophil aggregation upon P2Y 12 inhibition in the study by Thomas et al [48], another human experimental endotoxemia study by Schoergenhofer et al [17] found no influence of prasugrel on circulating levels of histone-DNA complexes. The latter serve as surrogates of extracellular traps derived from neutrophils (NETs), which can be formed following platelet toll-like receptor 4-mediated platelet-neutrophil aggregation [52].…”

“…However, both mechanisms are unlikely since clopidogrel and ticagrelor showed indistinguishable effects on circulating miRNAs; despite ticagrelor being an allosteric antagonist that does not require enzymatic activation and is present continuously in the plasma at therapeutic concentrations during treatment [45]. Instead, there is evidence that P2Y 12 inhibitors insufficiently reduce platelet reactivity during sepsis [15][16][17]. Patients on clopidogrel upon sepsis onset showed high on-treatment platelet reactivity in a prospective observational study, as determined by the VerifyNow point-of-care P2Y 12 assay [15].…”

“…One reason for limited success of antiplatelet drugs is high on-treatment platelet reactivity during sepsis. In fact, recent data suggests that sepsis promotes platelet activation despite treatment with P2Y 12 inhibitors, which are common antiplatelet drugs used in the secondary prevention of arterial thrombotic diseases [15][16][17]. Currently, there are no diagnostic tests that are able to inform treatment decisions and predict outcomes based on measurements of platelet reactivity in sepsis patients.…”

Coupling killing to neutralization: combined therapy with ceftriaxone/Pep19-2.5 counteracts sepsis in rabbits

“…16, 21 In fact, rabbits are notably less resistant to LPS than mice, although these non-rodents are still far from the exquisite sensitivity of humans to endotoxin. Thus, in current human studies, 2 ng kg −1 of LPS were used to induce endotoxemia; 22, 23, 24 however, in rabbits, a range of 1–10 μg kg −1 is applied in i.v. applications.…”