Keywords: SEB، انتروتوکسین استافیلوکوک B; DS, Down syndrome; HC, healthy controls; PBMCs, peripheral blood mononuclear cells; MFI, mean fluorescence intensity; SEB, staphylococcal enterotoxin B; TPO, thyroid peroxidase; Tg, thyroglobulin; TT, tetanus toxoid; mAb, monoclonal antibodyDown syndrome;