TPO and thyroid gland disorder: The association between gastric and thyroid disorders has been observed since the early 1960s when the frequent co-presence of the thyroid and gastric autoantibodies (anti-thyroperoxidase, anti-thyroglobulin, PCA, IFA) in patients with thyroid disorders and PA led Doniach B and Irvine WJ et al. to coin the expression “thyrogastric syndrome” [24,25,26,27].