Quantitative Thyroglobulin
(Specimen Container)
Serum Separator Tube (SST)
(Transport Temperature)
| Temperature | Period |
|---|---|
| Room temperature | Unacceptable |
| Refrigerated | 72 hours |
| Frozen | 30 days |
Gross hemolysis, Gross lipemia
Separate serum from cells within 45 minutes of venipuncture
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 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 Ab from binding endogenous TG.
0.5-55 ng/mL Reference interval does not apply following thyroidectomy when levels should be <0.5 ng/mL or repeatedly low. The presence of antithyroid antibodies may cause decreased levels of measurable thyroglobulin due to competitive inhibition in this immunometric assay.
