Schilddrüse Groß — Extended Thyroid Panel

Extended thyroid panel adding TPO antibodies and TSH receptor antibodies (TRAK) to the core fT3/fT4/TSH trio. Enables aetiological classification of thyroid dysfunction — distinguishing Hashimoto thyroiditis from Graves disease and non-autoimmune causes.

The extended thyroid panel builds on the Schilddruese Klein by adding the two most clinically important thyroid autoantibodies. While the core trio of TSH, fT3, and fT4 establishes whether thyroid function is normal, the antibody markers identify why it may be abnormal — a distinction that directly influences treatment decisions and long-term monitoring strategy. TPO antibodies (anti-thyroid peroxidase) are the hallmark of Hashimoto thyroiditis — the most common cause of hypothyroidism in iodine-sufficient populations, affecting 5-15% of women and 1-5% of men. Positive TPO antibodies indicate autoimmune thyroid destruction even when TSH and free hormones are still normal, identifying individuals at risk of future hypothyroidism. In patients with subclinical hypothyroidism (TSH 4-10, normal fT4), positive TPO antibodies increase the annual progression rate to overt hypothyroidism from 2-3% to approximately 5%, which influences the decision to treat versus monitor. TRAK (TSH receptor antibodies, also called TRAb or TSI) are pathognomonic for Graves disease — the most common cause of hyperthyroidism. These stimulating antibodies bind to the TSH receptor and activate thyroid hormone production independently of pituitary TSH. TRAK measurement is essential for differentiating Graves disease from toxic nodular goitre or thyroiditis, as each requires a different treatment approach. TRAK levels also predict the likelihood of relapse after antithyroid drug treatment — persistently elevated TRAK after 12-18 months of medication carries a high relapse risk and may favour definitive therapy (radioiodine or surgery). In clinical practice, this panel is indicated when: TSH is abnormal and the cause needs to be established; a family history of autoimmune thyroid disease is present; other autoimmune conditions exist (type 1 diabetes, coeliac disease, vitiligo); or a previous pregnancy was complicated by thyroid dysfunction. Thyroid antibodies should be checked at least once rather than repeatedly, as they tend to remain stable or gradually decline under treatment.