Thyroglobulin Antibodies (TG-AB)

What are Thyroglobulin Antibodies?

Thyroglobulin antibodies are autoantibodies that attack thyroglobulin, a protein made by the thyroid gland. These antibodies indicate an autoimmune response against thyroid tissue and are associated with various thyroid disorders, particularly Hashimoto’s thyroiditis.

Why is it Tested?

Doctors test thyroglobulin antibodies to diagnose autoimmune thyroid diseases, investigate unexplained thyroid dysfunction, monitor thyroid cancer patients (as they can interfere with thyroglobulin tumor marker testing), and assess thyroid autoimmunity risk.

Normal Ranges

Reference ranges for thyroglobulin antibodies:

Normal: <40 IU/L

Values above this threshold suggest thyroid autoimmunity, though some individuals may have elevated antibodies without overt thyroid dysfunction.

Reference ranges vary by authority. Track yours across multiple standards with automatic unit conversions in LabsVault.

What do Abnormal Results Mean?

Abnormal results are not a diagnosis. Always discuss your results with a qualified healthcare provider before making any medical decisions.

Normal/Low Antibodies

Negative results suggest:

No significant thyroid autoimmunity
Lower risk of autoimmune thyroid disease
Reliable thyroglobulin tumor marker testing

High Thyroglobulin Antibodies

Elevated levels may indicate:

Hashimoto’s thyroiditis
Graves’ disease (less common)
Thyroid cancer (occasionally)
Increased risk of thyroid dysfunction
Interference with thyroglobulin testing

How to Track Over Time

Thyroglobulin antibody levels can fluctuate over time and may remain elevated even after thyroid function normalizes. In thyroid cancer patients, monitoring helps interpret thyroglobulin tumor marker results. Declining antibody levels may indicate reduced autoimmune activity.

Thyroglobulin Antibodies