TPO and Alzheimer disease: Thus, it seems reasonable to perform antibody screening for thyroperoxidase (TPO) and thyroglobulin (TG), glutamic acid decarboxylase (GAD-65), islet cell cytoplasmic antigen (ICA), tyrosine phosphatase-like protein (IA2) and steroid 21 hydroxylase (21-OH) to reveal AITDs [24], T1D [25] and AD [26].