Distinct antibody groups in patients with vaccine-induced immune thrombotic thrombocytopenia (VITT) and their clinical implications

Ishac Nazy, Ph.D.
McMaster University
Hamilton, Ontario, Canada

Vaccine-induced immune thrombotic thrombocytopenia (VITT) caused by antibodies against platelet factor 4 (PF4) is a rare complication of the adenoviral vector-based vaccines against the SARS-CoV-2 virus. This presentation aims at identifying molecular and biochemical characteristics of the VITT anti-PF4 antibodies that correlate with the clinical presentation of cerebral venous thrombosis (CVST). This study concludes that the presence of a distinct subset of VITT anti-PF4 antibodies induce platelet activation without the addition of exogenous PF4 in the SRA and bind to two unique regions on the PF4 tetramer and its correlation with the presence of CVST.