Thyroglobulin Panel

Thyroglobulin Antibodies (TgAb) are autoantibodies directed against thyroglobulin, a protein produced by the thyroid gland essential for thyroid hormone synthesis. Elevated TgAb levels are a hallmark of Hashimoto's thyroiditis (autoimmune hypothyroidism) and can also be present in Graves' disease. Their presence indicates autoimmune activity against the thyroid. Ideally, levels should be negative or very low.

Thyroglobulin (Tg) is a protein produced exclusively by thyroid cells (normal or cancerous) and is the precursor for thyroid hormones. Its primary clinical use is as a tumor marker to monitor for recurrence of differentiated thyroid cancer after thyroidectomy and ablation. Levels should be undetectable or very low in that context. In individuals with an intact thyroid, levels vary and are less clinically significant unless TgAb are present (which interfere with the Tg assay, making Tg unreliable).