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Updated: Aug 19, 2026

A Microfluidic Flow Chamber Model for Platelet Transfusion and Hemostasis Measures Platelet Deposition and Fibrin Formation in Real-time
Published on: February 14, 2017
An IgG antiprothrombin antibody enhances prothrombin binding to damaged endothelial cells and shortens plasma
Objective:
To test the hypothesis that some lupus anticoagulants are antiprothrombin antibodies, and that such antibodies enhance prothrombin binding to endothelial cells (EC) and thus promote clotting on the cell surface.
Methods:
We generated a monoclonal antiprothrombin antibody (designated IS6) from a patient with primary antiphospholipid syndrome (APS). The antibody was analyzed for its binding properties, lupus anticoagulant activity, and pathophysiologic activity, using an EC-based plasma coagulation assay.
Results:
IS6 is the first patient-derived monoclonal IgG antiprothrombin antibody. It bound to prothrombin with low affinity, reacted with 3 phospholipids (cardiolipin, phosphatidylethanolamine, and phosphatidylserine), and showed lupus anticoagulant activity. Moreover, IS6 enhanced the binding of prothrombin to damaged EC and shortened the EC-based plasma coagulation times.
Conclusion:
These findings suggest that IS6 may promote coagulation in areas of damaged EC in the host, and thus contribute to thrombosis in patients with APS.
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08:01The Nijmegen Hemostasis Assay: Simultaneous Fluorogenic Measurement of Thrombin and Plasmin Generation in a Single Well
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