Background: Pre-eclampsia (P-EC) is associated with systemic inflammation, endothelial dysfunction and hypercoagulability. The role of extracellular vesicles (EVs) in coagulation disturbances affecting the development and severity of P-EC remains elusive. We aimed to evaluate the concentration of EVs expressing phosphatidylserine (PS) and specific markers in relation to the thrombin and fibrin formation as well as fibrin clot properties, in pregnant women with P-EC in comparison to healthy pregnant women of similar gestational age.Methods: Blood samples of 30 pregnant women diagnosed with P-EC were collected on the morning following admission to hospital and after delivery (mean duration 5 days). The concentration of the PS-exposing EVs (PS+ EVs) from platelets (CD42a⁺, endothelial cells (CD62E⁺), and PS+ EVs expressing tissue factor (TF) and vascular cell adhesion molecule 1 (VCAM-1) were measured by flow cytometry. Further phenotyping of EVs also included expression of PlGF. Markers of maternal haemostasis were correlated with EVs concentration in plasma.Results: Preeclamptic pregnancy was associated with significantly higher plasma levels of PS+ CD42a⁺ EVs and PS+ VCAM-1⁺ EVs in comparison with normotensive pregnancy. P-EC patients after delivery had markedly elevated concentration of PS+ CD42a⁺ EVs, CD62E⁺ EVs, TF⁺ EVs, and VCAM-1⁺ EVs compared to those before delivery. Inverse correlation was observed between EVs concentrations (PS+, PS+ TF⁺, and PlGF⁺) and parameters of overall haemostatic potential (OHP) and fibrin formation, while PS+ VCAM-1⁺ EVs directly correlated with FVIII activity in plasma.Conclusion: Increased levels of PS+ EVs subpopulations in P-EC and their association with global haemostatic parameters, as well as with fibrin clot properties may suggest EVs involvement in intravascular fibrin deposition leading to subsequent microcirculation disorders.

Background/Aim. Direct oral anticoagulants (DOACs) administration significantly interferes with coagulation as-says. The aim of the study was to evaluate the effect of DOACs and DOAC-Remove? on coagulation assays during thrombophilia testing. Methods. The study was carried out from January 2019 to the end of June 2020. It included 30 DOAC-treated patients, 14 females and 16 males aged 23 to 63 (median age 47.6 years), tested for thrombophilia due to venous thromboembolism (VTE). Thrombophilia testing was performed using DOAC-Remove? tablets (activated charcoal). The results before and after DOAC-Remove? were compared. Results. Positive lupus anticoagulant (LA) results were observed in 20% apixaban, 100% dabigatran, and 70% rivaroxaban-treated patients, while in samples after DOAC-Remove?, the LA positivity was observed only in one from the apix-aban group. Before DOAC-Remove?, the activated protein C (APC) resistance (APC-R) was measurable in 40% dabigatran and 80% rivaroxaban-treated patients, while, after using DOAC-Remove?, the APC-R was measurable in all cases. Comparing the results obtained from the samples before and after DOAC-Remove?, a difference was noted in relation to all dilute Russell?s viper venom time (dRVVT) coagulation tests, except for the dRVVT ratio in the apixaban group. Clot-based methods for detecting the APC resistance were significantly affected by dabigatran and less by rivaroxaban. Conclusion. DOACs were practically inactivated after the addition of the DOAC-Remove?, which made it possible to perform analyses for the LA and APC-R testing freely and obtain relevant results.