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Updated: Dec 10, 2025

Flow Cytometry Analysis of Tissue Factor Expression in Human Platelets
Published on: November 22, 2024
Coronavirus 2019, Microthromboses, and Platelet Activating Factor
Theoharis C Theoharides1, Smaragdi Antonopoulou2, Constantinos A Demopoulos3
1Laboratory of Molecular Immunopharmacology and Drug Discovery, Department of Immunology, Tufts University School of Medicine, Boston, MA, USA; School of Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA; Department of Internal Medicine, Tufts University School of Medicine and Tufts Medical Center, Boston, MA, USA.
Abstract:
Recent articles have reported elevated markers of coagulation, endothelial injury, and microthromboses in lungs from deceased patients with coronavirus 2019 (COVID-19). Platelets are critical in the formation of thrombi, and their most potent trigger is platelet activating factor (PAF). PAF is produced by cells involved in host defense, and its biological actions bear similarities with COVID-19 disease manifestations, including pulmonary microthromboses and inflammation, possibly via activation of mast cells. The histamine1 receptor antagonist rupatadine was developed to have anti-PAF activity and inhibits activation of human mast cells in response to PAF. Rupatadine could be repurposed for COVID-19 prophylaxis.
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