Thyroid Antibodies is to diagnose and monitor autoimmune thyroid diseases and to distinguish these from other forms of thyroid disease; to help guide treatment decisions.
When you have an enlarged thyroid (goiter) and/or when your other thyroid tests, such as total or free T3, free T4, and TSH, indicate thyroid dysfunction; along with a thyroglobulin test when your healthcare provider is using it as a monitoring tool.
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.