test directorySearch Results
Click here to search again.
Test Name:
Thyroglobulin Antibodies
- SBMF No:
30020 - Performance Lab Name:
Manual Lab - Test Mnemonic:
THYROGL AB - ABN:
Not required - CPT Code:
86800 - LOINC Code:
8098-6 - Also Known As:
Anti-Tg
Tg Ab
Thyroglobulin Antibodies
Thyroglobulin Autoantibodies
Anti-Thyroglobulin Antibodies
Anti Tg - Also See:
30022 Thyroglobulin with Thyroglobulin Antibodies - Spec Type:
Serum - Spec Container:
Gold top (SST) or red top (serum) tube - Alt Spec Type:
Plasma - Alt Spec Container:
Green top (lithium heparin) tube - Pref Vol:
1.0 mL - Min Vol:
0.5 mL - Fasting:
No - Spec Collect:
Routine venipuncture - Spec Process:
Clot 30 minutes
Promptly centrifuge 15 minutes
Immediately transfer serum to separate plastic tube - Spec Store Transport:
Refrigerated - Spec Stability:
1 week refrigerated (2-8°C)
2 months frozen (-20°C) – Do not use frost-free units that undergo repeated freeze/thaw cycles - Spec Reject:
Hemolyzed sample - Methodology:
Chemiluminescent Immunoassay (CLIA) - Use:
Primarily used to diagnose autoimmune thyroiditis - Clinical Significance:
Autoantibodies to thyroglobulin are found in many patients with autoimmune disorders of the thyroid gland. Thyroglobulin is a 660,000 MW glycoprotein composed of two subunits. It is a secretory product of only the thyroid gland and is present in the serum of normal individuals. The thyroid hormones thyroxine (T4) and triiodothyronine (T3) are synthesized from tyrosine residues of thyroglobulin in the thyroid epitheliel cell. Thyroglobulin itself is not biologically active, and composes about 75% of the total protein of the thyroid follicular colloid (lumen). T4 and T3 are only released after thyroglobulin is endocytosed and proteolytically degraded in the thyrocyte.Autoantibodies to thyroglobulin appear to result from the inheritance of a dominant Mendelian trait in women and reduced penetrance in men. The autoantibodies are polyclonal with no restriction of light-chain type or heavy-chain subclass. In addition, there is evidence that suggests that the levels of autoantibodies of any given isotype to specific epitopes may vary from individual to individual. The presence of TgAb have been reported in a number of autoimmune disorders. Autoimmune thyroiditis was first described by Hashimoto in 1912 and the goitrous form is now generally called Hashimoto’s thyroiditis. The generic term autoimmune thyroid disease would include Hashimoto’s thyroiditis, lymphocytic, postpartum, and silent thyroiditis, idiopathic (primary) hypothyroidism and Graves disease. TgAb may be present in unclear cases of suspected thyroid autoimmunity (where the TPOAb is negative). The detection of thyroid autoantibodies and the measurement of thyroid stimulating hormone (TSH) can be useful in determining the diagnosis and management of autoimmune thyroid disordersIn autoimmune thyroid diseases, a broad spectrum of antibodies can be detected. Two of the most significant are thyroglobulin antibodies (anti-Tg) and thyroid peroxidase antibodies (anti-TPO). These antibodies are known to occur typically in autoimmune thyroiditis. The measurement of thyroglobulin antibodies is only relevant in cases where thyroid peroxidase antibodies are negative and an autoimmune thyroid disease is suspected. Thyroglobulin antibodies are elevated in 60 to 70% of the patients with Hashimoto's thyroiditis and primary myxedema, as well as in 20 to 40% of patients with Graves disease. - Reference Range:
Less than or equal to 40 IU/mL - Additional Test Info:
As many as 10% of euthyroid patients may present with elevated levels of thyroid autoantibodies. In rare cases, interference from extremely high concentrations of anti-streptavidin and/or anti-biotin antibodies may occur leading to an erroneous result. Interference from Rheumatoid Factor as well as anti-TSH, anti-T3 and anti-T4 autoantibodies may occur. - Day Run:
Mon, Wed, Fri - Time Run:
8:00 am - Time Reported:
3:30 pm - Test Type:
IMMUNOLOGY
