Use

Thyroglobulin (TG) is a secretory product only of the thyroid gland. The major clinical use of serum TG measurement is to monitor—but not to diagnose—patients with well‑differentiated thyroid cancers. Measurement of thyroglobulin after thyroidectomy and ablation of the thyroid gland is useful to determine metastases. Deficient TG synthesis is observed in infants with goitrous hypothyroidism. Most patients with thyroid autoimmune disease have thyroglobulin antibody. In immunometric (sandwich) assays, TG antibody interference typically produces inappropriately low TG results, most likely caused by endogenous TG immune complexes that block one or more of the reagent antibodies from binding endogenous TG.