Genetic predisposition to vaccine-induced immune thrombotic thrombocytopenia.

Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a rare prothrombotic disorder with a unique clonality-restricted immunological profile. The study by Petito and Bury et al. provides insight into the role of HLA polymorphisms and an inherent predisposition to VITT. Commentary on: Petito et al. Association of human leucocyte antigen loci with vaccine-induced immune thrombotic thrombocytopenia: Potential role of the interaction between platelet factor 4-derived peptides and MHC-II. Br J Haematol 2025; 206:290-295.