Antithyroid Antibodies test is done if doctors think that the patient has Hashimoto’s disease or Graves’ disease or Goiter. An antibody test can help your doctor figure out if your immune system is attacking the thyroid gland, or if something else might be the cause. A lab technician will take a sample of your blood to measure how many antithyroid antibodies are in it.
Testing may be ordered when an individual has abnormal TSH and/or free T4 test results or signs and symptoms of a low or high level of thyroid hormones or the presence of a goiter, especially if the cause is suspected to be an autoimmune disease.
The reference ranges for antithyroid antibodies are as follows: Thyroid peroxidase antibody (TPOAb): Less than 35 IU/mL. Thyroglobulin antibody (TgAb): Less than 20 IU/mL. Thyroid-stimulating immunoglobulin antibody (TSI): Less than 140% of basal activity.