Thyroid Antibodies (TG & TPO), Serum

Thyroid antibodies test is done to diagnose an autoimmune thyroid disease and to differentiate it from other thyroid disorders. Thyroid autoantibodies develop when the immune system identifies the normal thyroid gland or thyroid proteins as a foreign body, targets them leading to inflammation, damage of the tissue and disruption of the function. The following tests are done to diagnose and monitor an autoimmune thyroid disorder Thyroid auto antibody -Thyroid peroxidase antibody (TPO) is the most common test done for autoimmune thyroid diseases (Graves disease or Hashimoto thyroiditis). Thyroid auto antibody -Thyroglobulin antibody (TGAb) targets thyroglobulin which is the storage form of thyroid hormones. These tests may be ordered when thyroid gland is enlarged (goiter), when other thyroid tests (total or free T3, free T4, TSH, thyroglobulin ) are abnormal, to monitor treatment of an autoimmune thyroid disorder. These thyroid antibody tests are done in autoimmune patients (systemic lupus erythematosus, rheumatoid arthritis, or pernicious anemia) to assess their risk of developing a thyroid disorder. A person who is receiving treatment for thyroid cancer may be monitored with a thyroglobulin test. In this case, the thyroglobulin antibody test is done in a thyroid cancer patient receiving treatment to determine if the antibody is present in the blood and is likely to interfere with the thyroglobulin level.

1. Are thyroid antibodies routinely tested?

No, they are only done when there is an enlarged thyroid gland or symptoms of thyroid disorders.

2. What are autoimmune disorders of thyroid?

Graves and Hashimoto's thyroiditis.