thyroglobulin panel test

Thyroperoxidase (TPO) antibodies are immune proteins that target the thyroid enzyme responsible for producing thyroid hormones. Elevated TPO antibody levels indicate autoimmune thyroid disease, most commonly Hashimoto's thyroiditis. This test is performed on serum or plasma and is one of the most important thyroid autoimmunity markers. High TPO antibody levels often precede thyroid dysfunction and predict progression to hypothyroidism. They are also associated with other autoimmune conditions and may affect fertility and pregnancy outcomes.

Thyroglobulin is a protein produced by thyroid cells and used as a tumor marker for thyroid cancer, particularly papillary and follicular types. When measured in lymph node samples obtained through fine needle aspiration, it helps determine whether cancer cells are present in the lymph nodes. High thyroglobulin levels in lymph node samples suggest thyroid cancer involvement. This test is typically used after thyroid cancer diagnosis to assess the extent of disease and guide treatment planning.