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Thyroglobulin Antibody (Tg-Ab) Quantitative

Published: July 27, 2026Updated: August 25, 2026

This biomarker measures the levels of thyroglobulin antibodies in the blood, which can indicate autoimmune thyroid disorders.

Quick summary

Tg-Ab levels help diagnose autoimmune thyroid conditions like Hashimoto's thyroiditis.

Medically reviewed by WellAlly Editorial TeamLast reviewed August 25, 2026Editorial policy

Key facts at a glance

Units
IU/mL
Clinical utility
diagnostic
Result kind
quantitative
FDA-cleared
Roche Anti-Tg Quant, Abbott Anti-Tg Quant
interpretation: {"text":"Normal range; autoimmune thyroid disorder unlikely.","label":"0–20 IU/mL"}; {"text":"Elevated levels may indicate autoimmune thyroid disease.","label":">20 IU/mL"}

Thyroglobulin antibodies (Tg-Ab) are produced by the immune system and target thyroglobulin, a protein essential for thyroid hormone production. Elevated levels of Tg-Ab can signify an autoimmune response against the thyroid gland.

The quantitative measurement of Tg-Ab is crucial for diagnosing and monitoring conditions such as Hashimoto's thyroiditis and Graves' disease. It is often used in conjunction with other thyroid function tests to provide a comprehensive assessment.

Normal reference ranges for Tg-Ab are typically between 0–20 IU/mL. Results above this range may indicate the presence of an autoimmune thyroid disorder, prompting further investigation and management.

Frequently asked questions

What conditions can cause elevated Tg-Ab levels?
Elevated Tg-Ab levels are commonly associated with autoimmune thyroid disorders such as Hashimoto's thyroiditis and Graves' disease.
How is the Tg-Ab test performed?
The test involves a simple blood draw, which is then analyzed in a laboratory to measure the concentration of thyroglobulin antibodies.
  1. 1
    American Thyroid AssociationSource
  2. 2
    Mayo ClinicSource

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This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

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Medically reviewed by WellAlly Editorial Team Last reviewed August 25, 2026. · Read our editorial policy