TPO and hypothyroidism: Testing of thyroid function revealed severe hypothyroidism due to HT, characterized by high TSH levels (236.6 mIU/l, n.v. 0.3-4.2 mIU/l), low FT4 (0.25 ng/dl, n.v. 0.9-1.7 ng/dl), and high titers of anti-thyroglobulin (TG-Ab) and anti-thyroperoxidase antibodies (TPO-Ab) (>3000 and >1200 UI/ml, respectively).