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HelpTest Code Billings Clinic: 1921 Mayo: TGAB Thyroglobulin Antibody, Serum
Reporting Name
Thyroglobulin Antibody, SPerforming Laboratory
Mayo Clinic Laboratories in Rochester
Useful For
As an adjunct in the diagnosis of autoimmune thyroid diseases: Hashimoto disease, postpartum thyroiditis, neonatal hypothyroidism, and Graves disease
Method Name
Immunoenzymatic Assay
Ordering Guidance
For the follow-up of patients with differentiated follicular cell-derived thyroid carcinomas, consider either HTG2 / Thyroglobulin, Tumor Marker, Serum or HTGR / Thyroglobulin, Tumor Marker Reflex, Serum.
The preferred method for confirming Graves disease in atypical cases or under special clinical circumstances is measurement of the pathogenic antithyrotropin receptor antibodies by binding assay or bioassay. Order either THYRO / Thyrotropin Receptor Antibody, Serum or TSI / Thyroid-Stimulating Immunoglobulin, Serum.
Specimen Required
Patient Preparation: For 12 hours before specimen collection, do not take multivitamins or dietary supplements containing biotin (vitamin B7), which is commonly found in hair, skin, and nail supplements and multivitamins.
Container/Tube: Red top (gel tubes/SST are not acceptable)
Specimen Volume: 0.6 mL
Collection Instructions: Centrifuge and aliquot serum within 2 hours of collection.
Specimen Type
Serum RedSpecimen Minimum Volume
0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time | Special Container |
|---|---|---|---|
| Serum Red | Refrigerated (preferred) | 7 days | |
| Frozen | 30 days | ||
| Ambient | 7 days |
Reject Due To
| Gross hemolysis | Reject |
| Gross lipemia | OK |
| Gross icterus | Reject |
Reference Values
<4.0 IU/mL
Reference values apply to all ages.
Interpretation
Diagnosis of Autoimmune Thyroid Disease:
Measurements of antithyroperoxidase (anti-TPO) have higher sensitivity and equal specificity to antithyroglobulin (anti-Tg) measurements in the diagnosis of autoimmune thyroid disease. Anti-Tg levels should, therefore, only be measured if anti-TPO measurements are negative but clinical suspicion of autoimmune thyroid disease is high.
Detection of significant titers of anti-Tg or anti-TPO autoantibodies is supportive evidence for a diagnosis of Graves disease in patients with thyrotoxicosis. However, measurement of the pathogenic antithyrotropin receptor antibodies by binding assay (THYRO / Thyrotropin Receptor Antibody, Serum) or bioassay (TSI / Thyroid-Stimulating Immunoglobulin, Serum) is the preferred method of confirming Graves disease in atypical cases and under special clinical circumstances.
Positive thyroid autoantibody levels in patients with high-normal or slightly elevated serum thyrotropin levels predict the future development of more profound hypothyroidism.
Patients with postpartum thyroiditis with persistently elevated thyroid autoantibody levels have an increased likelihood of permanent hypothyroidism.
In cases of neonatal hypothyroidism, the detection of anti-TPO or anti-Tg in the infant suggests transplacental antibody transfer, particularly if the mother has a history of autoimmune thyroiditis or detectable thyroid autoantibodies. The neonatal hypothyroidism is likely to be transient in these cases.
Day(s) Performed
Monday through Saturday
Report Available
1 to 3 daysTest Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
86800
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| TGAB | Thyroglobulin Antibody, S | 56536-6 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| TGAB | Thyroglobulin Antibody, S | 56536-6 |