Thyroglobulin antibodies (TgAb) are immune proteins that target thyroglobulin — a key protein used by the thyroid gland to produce thyroid hormones. The presence of thyroglobulin antibodies can indicate autoimmune thyroid conditions, most commonly Hashimoto's thyroiditis (the leading cause of hypothyroidism) and Graves' disease. Elevated TgAb levels suggest the immune system is actively attacking thyroid tissue, which can lead to gradual thyroid damage and dysfunction. This test is also important in monitoring thyroid cancer patients, as the presence of TgAb can interfere with thyroglobulin measurements used to detect cancer recurrence. Diagnostic Blood Test: Thyroglobulin Antibody Note: This test may exhibit interference when sample is collected from a person who is consuming a supplement with a high dose of biotin. Cease biotin supplementation at least 72 hours prior to blood draw.
