CD8A and autoimmune thrombocytopenic purpura: Many studies have demonstrated that CD8+ cytotoxic T lymphocytes (CTLs) from peripheral blood or spleen of ITP patients can directly lyse platelets or induce platelet apoptosis through granzyme B and perforin [44–47], although the target platelet MHC class I peptides recognized by CD8+ T cells have not yet been identified.