[Tissue factor expression of platelets and leukocytes in patients with acute coronary syndromes]

The aim of this study was to investigate the tissue factor (TF) expression of platelets and leukocytes in patients with acute coronary syndrome (ACS), patients with stable angina (SA) and healthy subjects (as controls). 26 patients with ACS, 29 patients with SA, and 25 controls were enrolled in this study. The peripheral blood samples of above-mentioned subjects were collected and isolated to obtain the monocytes and platelet-rich plasma, the TF-mRNA expression of monocytes, and platelets among 3 groups was detected by RT-PCR, the TF expression ratio of platelets, platelet-leukocyte aggregates (PLA) and platelet-monocyte aggregates (PMP) was detected by flow cytometry among 3 groups. The results showed that the TF mRNA expression level of platelets in ACS group were significantly higher (3.11 ± 0.51 relative expression) as compared with SA and control groups (1.88 ± 0.78 and 0.7 ± 0.1, respectively) (P = 0.03). Expression of TF mRNA of monocytes was higher in ACS group (P = 0.05 versus controls) too. ACS group had a significantly higher amount of TF-positive platelets (8.8 ± 2.6) than SA (2.6 ± 0.5, P = 0.02) or control groups (2.5 ± 0.4, P = 0.02). A significantly greater number of TF positive platelet-leukocyte aggregates and platelet-monocyte aggregates were also found by flow cytometry in blood of ACS patients than in either SA patients or controls. It is concluded that the high TF expression of platelets and leukocytes in ACS patients strengthens the platelet activation, blood coagulation, and thrombus formation and may further contribute to the hypercoagulability associated with the disease. The present study further extends the proinflammatory/prothrombotic phenotype of ACS patients showing that new players on the scene.