Geri

Thyroglobulin (TG) is an iodinated protein involved in the synthesis of thyroid hormones. The detection of anti-thyroglobulin antibodies (Anti-TG) is an important marker for diagnosing autoimmune thyroid diseases, such as:

  • Hashimoto’s thyroiditis
  • Atrophic autoimmune thyroiditis
  • Graves' disease (Diffuse toxic goiter)

Significance of Anti-TG Testing

  • Combined testing of Anti-TG and Anti-TPO (anti-thyroid peroxidase antibodies) helps in diagnosing Hashimoto’s thyroiditis and identifying primary idiopathic hypothyroidism.
  • In Hashimoto’s thyroiditis, Anti-TG levels generally decrease during treatment, but in some cases, they may persist for 2–3 years.
  • Anti-TG levels correlate more strongly with TSH (thyrotropin) than with thyroglobulin levels.
  • Testing for Anti-TG is especially useful in iodine-deficient regions, where autoimmune thyroid diseases are more prevalent.
  • The test is performed on a venous blood sample.
  • Blood can be drawn at least 4 hours after a light meal.

In Newborns:

  • High Anti-TG levels in the mother may indicate potential thyroid dysfunction in the infant.

In Adults:

  • Chronic thyroiditis (e.g., Hashimoto’s thyroiditis)
  • Differential diagnosis of hypothyroidism
  • Graves' disease (Diffuse toxic goiter)
  • Pretibial myxedema

Causes of Increased Anti-Thyroglobulin Antibody (Anti-TG) Levels

  • Chronic thyroiditis (e.g., Hashimoto’s thyroiditis)
  • Idiopathic hypothyroidism
  • Autoimmune thyroiditis
  • Diffuse toxic goiter (Graves' disease)
  • Down syndrome (mildly positive result)