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Test Code ATG or LAB533 Thyroglobulin Antibody, Serum

Important Note

Patient Preparation: For 12 hours before this test, do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.   Biotin can interfere with many immunoassay tests.

Specimen Requirements

Container Type:

Optimal: Gold 

Acceptable: Red
Optimal Collection Volume: 

4.5mL; full tube
Minimum Volume:

1 mL whole blood
Collection Instructions:

Gently invert the sample 5-6 times after collection.
Specimen Transport:

Refrigerate
Processing Instructions: 

1. Allow the specimen to clot for 30 minutes.

2. Centrifuge specimen within 2 hours of collection.

3. After centrifugation, specimen tubes without a gel barrier should have the serum aliquoted to a false bottom container.

4. Keep the serum refrigerated until testing can be performed.

Specimen Stability

Specimen Type Temperature Time
Serum Refrigerated 4 days
Room Temperature 4 days
Frozen 2 months

Specimen Rejection Criteria

Hemolysis Mild OK; Moderate OK; Gross Reject
Lipemia Mild OK; Moderate OK; Gross Reject
Icterus Mild OK; Moderate OK; Gross Reject
Other Quantity not sufficient

Useful For

This assay is useful as an adjunct in diagnosing various autoimmune thyroid diseases such as Graves' Disease or Hashimoto's Disease.  

Methodology

Roche Cobas - Electrochemiluminescence immunoassay

 

Note: Patient results determined by assays using different manufacturers for methods may not be comparable

Reference Ranges

< 115 IU/mL

Interpretive

Elevated serum concentrations of antibodies against Tg (Tg-autoantibodies) are found in subjects with autoimmunity-based thyroiditis. High concentrations of anti-Tg, together with anti-TPO, are indicative of chronic lymphocytic-infiltrative thyroiditis (Hashimoto's disease). The frequency of thyroglobulin antibodies is approx. 70-80 % in subjects with autoimmune thyroiditis, including Hashimoto's disease, and approx. 30 % in individuals with Graves' disease. The anti-Tg assay is important for monitoring the course of Hashimoto's thyroiditis2 and for the differential diagnosis (cases of suspected autoimmune thyroiditis of unknown origin with negative anti-TPO test results, Graves' disease without lymphocytic infiltration, and to rule out interference by Tg-autoantibodies in the Tg test).

Day(s) Performed

24/7

Expected TAT

Same day

Performing Laboratory

Bronson Laboratory, Chemistry - Kalamazoo

Sample Retention Time

7 days

CPT Code

86800

LOINC Code

56536-6