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Updated: Jun 2, 2026
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Determination of the Procoagulant Activity of Extracellular Vesicle (EV) Using EV-Activated Clotting Time (EV-ACT)
Published on: August 4, 2023
Microparticles in hemostasis and thrombosis.
A Phillip Owens1, Nigel Mackman
1Division of Hematology/Oncology, Department of Medicine, McAllister Heart Institute, University of North Carolina at Chapel Hill, North Carolina, USA.
Circulation Research
|May 14, 2011
Summary
Procoagulant microparticles (MPs) carrying phosphatidylserine (PS) and tissue factor (TF) are elevated in disease, particularly cancer. These MPs, mainly from monocytes, may indicate thrombosis risk.
Area of Science:
- Hematology
- Oncology
- Biochemistry
Background:
- Blood contains microparticles (MPs) from various cells, including platelets, monocytes, and endothelial cells, as well as from tumors.
- All MPs are procoagulant, providing a surface for coagulation factors, with activity enhanced by phosphatidylserine (PS) and tissue factor (TF).
- Healthy individuals have high platelet-derived PS(+) MPs, but low levels of TF(+) MPs.
Purpose of the Study:
- To review the role of procoagulant MPs in hemostasis and thrombosis.
- To highlight the significance of PS(+) TF(+) MPs as potential biomarkers.
Main Methods:
- Literature review summarizing current knowledge on MPs in hemostasis and thrombosis.
- Focus on the cellular sources and clinical implications of procoagulant MPs.
Main Results:
- PS(+) TF(+) MPs are detected in various diseases, with monocytes as the primary source.
- In cancer, PS(+) TF(+) MPs originate from tumors.
- Elevated PS(+) TF(+) MPs may identify cancer patients at risk for venous thrombosis.
Conclusions:
- Procoagulant MPs, especially PS(+) TF(+) MPs, play a crucial role in hemostasis and thrombosis.
- Monocyte-derived PS(+) TF(+) MPs are key indicators in disease states like cancer.
- These MPs show promise as biomarkers for predicting venous thrombosis risk in cancer patients.
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