Monoclonal and oligoclonal anti-platelet factor 4 antibodies mediate VITT
Adam J. Kanack, Antonios Bayas, Gemlyn George, Mouhamed Yazan Abou‐Ismail, Bandana Singh, Mindy Kohlhagen, Noah P. Splinter, Monika Christ, Markus Naumann, Karen Moser, Kristi J. Smock, Alison Grazioli, Renren Wen, Demin Wang, David Murray, Anand Padmanabhan
Abstract
Kanack and colleagues analyze anti-platelet factor 4 antibodies from 5 patients with vaccine-induced thrombotic thrombocytopenia (VITT) secondary to COVID-19 adenoviral vaccination and antibodies from patients with spontaneous heparin-induced thrombocytopenia (HIT) and classical HIT. VITT antibodies are monoclonal or oligoclonal, similar to spontaneous HIT, whereas classical HIT antibodies are polyclonal. Heparin inhibits antibody-induced platelet activation in VITT, suggesting that heparin should be considered for the treatment of VITT.