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Updated: Jan 30, 2026

Author Spotlight: High-Sensitivity Tissue Factor Activity Assay for Plasma Diagnosis
Published on: December 29, 2023
Measurement of tissue factor activity in extracellular vesicles from human plasma samples
Yohei Hisada1, Nigel Mackman1,2
1Division of Hematology and Oncology, Thrombosis and Hemostasis Program Department of Medicine University of North Carolina at Chapel Hill Chapel Hill North Carolina.
Abstract:
Tissue factor (TF) is the cellular receptor for plasma factor (F) VII/FVIIa and triggers blood coagulation. Extracellular vesicles (EVs) are small membrane vesicles that are released from activated cells and tumor cells. Different cell types, including activated monocytes and tumors cells release TF-positive EVs into the circulation. We developed an assay to measure levels of TF activity in EVs isolated from human plasma samples. We and others have used this assay to demonstrate increased levels of EV TF activity in a variety of diseases associated with thrombosis, including cancer. These studies suggest that EV TF can be used as a biomarker of thrombotic risk. The strength of this laboratory assay is that it is relatively sensitive and specific. However, the limitations of the assay are that it is labor intensive and the coefficient of variation is too high for it to be used as a clinical assay.
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