Phosphatidylserine Exposing Extracellular Vesicles in Pre-eclamptic Patients

Area of Science:

• Obstetrics and Gynecology
• Hematology
• Vascular Biology

Background:

• Pre-eclampsia (P-EC) involves systemic inflammation, endothelial dysfunction, and hypercoagulability.
• The specific role of extracellular vesicles (EVs) in P-EC-related coagulation disturbances is not fully understood.

Purpose of the Study:

• To evaluate the concentration of phosphatidylserine-exposing EVs (PS+ EVs) and specific EV markers in pre-eclamptic women.
• To correlate EV concentrations with thrombin and fibrin formation, and fibrin clot properties.
• To compare EV levels in pre-eclamptic versus healthy pregnant women.

Main Methods:

• Collected blood samples from 30 pre-eclamptic women (pre- and post-delivery) and healthy controls.
• Measured PS+ EVs from platelets, endothelial cells, and EVs expressing tissue factor (TF) and VCAM-1 via flow cytometry.
• Assessed PlGF expression on EVs and correlated EV concentrations with maternal hemostasis markers.

Main Results:

• Pre-eclamptic pregnancies showed higher plasma levels of PS+ CD42a+ EVs and PS+ VCAM-1+ EVs compared to normotensive pregnancies.
• Post-delivery, P-EC patients had significantly elevated PS+ CD42a+ EVs, CD62E+ EVs, TF+ EVs, and VCAM-1+ EVs.
• EV concentrations (PS+, PS+ TF+, PlGF+) inversely correlated with overall hemostatic potential and fibrin formation; PS+ VCAM-1+ EVs directly correlated with FVIII activity.

Conclusions:

• Elevated PS+ EV subpopulations in P-EC suggest their involvement in coagulation disturbances.
• EVs may contribute to intravascular fibrin deposition and microcirculation disorders in pre-eclampsia.
• Further research into EVs' role in P-EC pathogenesis is warranted.