Thyroglobulin Antibodies
Antibodies against thyroglobulin, another marker of autoimmune thyroid disease.
| Typical reference range | below 1 IU/mL |
Ranges vary by laboratory, method, age and sex: always use the range printed on your own report. Why labs differ.
What it measures
Thyroglobulin is the protein in which thyroid hormones are made and stored. Antibodies against it are produced in autoimmune thyroid conditions.
Why it matters
TgAb supports a diagnosis of Hashimoto's thyroiditis, particularly when TPO antibodies are negative, and must be measured when thyroglobulin is used to monitor thyroid cancer, since TgAb interferes with that test.
What a high result can mean
Elevated levels suggest Hashimoto's or Graves' disease; low-level positivity also occurs in some healthy people and in thyroid cancer.
What a low result can mean
Negative results are normal.
What affects the result
Cut-offs differ between assays (Quest at or below 1 IU/mL; Labcorp below 0.9 IU/mL). Interpret with TPO antibodies and TSH.
Units and conversion
Usually reported in IU/mL.
- From kIU/L: multiply by 1 to get IU/mL
- From U/mL: multiply by 1 to get IU/mL
Also called on lab reports
Thyroglobulin Antibody, Antithyroglobulin Ab, TgAb, Anti-Thyroglobulin, Tg Ab, Thyroglobulin Antibodies (TgAb), Anti-Thyroglobulin Antibody
Related tests: Thyroid
This page is educational and does not replace advice from a healthcare professional.