Platelet-neutrophil aggregate formation induces NLRP3 inflammasome activation in vaccine-induced thrombotic thrombocytopenia.

Background: Although rare, vaccine-induced thrombotic thrombocytopenia (VITT) following adenoviral vector COVID-19 vaccination is a concerning and often severe adverse effect of vaccination. The generation of high antiplatelet factor 4 antibody titers promotes the formation of immune complexes capable of activating platelets and neutrophils through FcγRIIa.

Objectives: Given that platelet-leukocyte aggregate formation and inflammasome activation are common features of thromboinflammatory diseases, we aimed to evaluate if these are also features of VITT.