Test Library

Includes Thyroglobulin, Thyroglobulin Antibodies

Preferred Specimen(s) 2 mL serum

Transport Container Plastic screw-cap vial

Transport Temperature Refrigerated, stable 7 day’s

Reject Criteria

  • Gross hemolysis
  • Hyperlipemia

Methodology Chemiluminescene

Clinical Significance 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. The measurement of thyroglobulin, after thyroidectomy and ablation of the thyroid gland, is useful to determine metastasis. Deficient TG synthesis is observed in infants with goitrous hypo-thyroidism. Most patients with thyroid autoimmune disease have thyroglobulin antibody. The antiperoxidase antibody (anti-tpo) provides additional specificity. Approximately 95% of patients with diffuse goiter, hypothyroidism, or both have anti-tpo. Anti-tpo is especially useful with patients with subclinical hypothyroidism (elevated TSH and normal free T4 concentrations). Many of these patients will develop hypothyroidism. With immunometric assays (sandwich assays), TGAB 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.