Evaluation of the profile of circulating extracellular vesicles of different cell origin and their activity in patients with postthromboembolic syndrome

Abstract

Background. Chronic thromboembolic pulmonary hypertension (CTEPH) and chronic thromboembolic disease (CTEP) are manifestations of post-thromboembolic syndrome in patients with pulmonary embolism. Extracellular vesicles (EVs) are involved in the pathogenesis of these diseases due to the activation of the hemostasis system.Objective. Evaluation of the relative amount of EVs and their coagulation activity using the thrombin generation test in CTEP and CTEPH patients. Design and methods. The study included 21 patients: the CTEP group (n = 7) and the CTEPH group (n = 14); and 11 healthy donors. EVs were isolated with the Exo-FACS kit and analyzed by flow cytometry using fluorescently labeled antibodies. The activity of the microparticles was assessed in a thrombin generation test using a trigger reagent without the addition of TF using a plate fluorimeter.Results. The relative content of EVs of platelet and endothelial origin was increased in CTEPH and CTEP groups. The level of platelet EVs correlates with the levels of CRP and D-dimer. LT and ttPeak were significantly increased in patients with CTEPH.Conclusion. An increase in the level of platelet and endothelial EVs in patients with CTEPH and CTEP indicates the contribution of microvesiculation to the formation of post-thromboembolic syndrome. The activity of thrombin generation decrease under the action of TF-EVs could be a result of TF consumption in endothelial dysfunction, or prolonged activation of procoagulant pathways.