1. Antibodies against Platelet Glycoproteins in Clinically Suspected VITT Patients
- Author
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Romy T. Meier, Leendert Porcelijn, Suzanne Hofstede-van Egmond, Camila Caram-Deelder, Jonathan M. Coutinho, Yvonne M. C. Henskens, Marieke J. H. A. Kruip, An K. Stroobants, Jaap J. Zwaginga, C. Ellen van der Schoot, Masja de Haas, and Rick Kapur
- Subjects
platelet-autoantibodies ,thrombocytopenia ,thrombosis ,COVID-19 ,vaccination ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Vaccine-induced thrombotic thrombocytopenia (VITT) is a rare but severe complication following COVID-19 vaccination, marked by thrombocytopenia and thrombosis. Analogous to heparin-induced thrombocytopenia (HIT), VITT shares similarities in anti-platelet factor 4 (PF4) IgG-mediated platelet activation via the FcγRIIa. To investigate the involvement of platelet-antibodies in VITT, we analyzed the presence of platelet-antibodies directed against glycoproteins (GP)IIb/IIIa, GPV and GPIb/IX in the serum of 232 clinically suspected VITT patients determined based on (suspicion of) occurrence of thrombocytopenia and/or thrombosis in relation to COVID-19 vaccination. We found that 19% of clinically suspected VITT patients tested positive for anti-platelet GPs: 39%, 32% and 86% patients tested positive for GPIIb/IIIa, GPV and GPIb/IX, respectively. No HIT-like VITT patients (with thrombocytopenia and thrombosis) tested positive for platelet-antibodies. Therefore, it seems unlikely that platelet-antibodies play a role in HIT-like anti-PF4-mediated VITT. Platelet-antibodies were predominantly associated with the occurrence of thrombocytopenia. We found no association between the type of vaccination (adenoviral vector vaccine versus mRNA vaccine) or different vaccines (ChAdOx1 nCoV-19, Ad26.COV2.S, mRNA-1273, BTN162b2) and the development of platelet-antibodies. It is essential to conduct more research on the pathophysiology of VITT, to improve diagnostic approaches and identify preventive and therapeutic strategies.
- Published
- 2024
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