The Anti-TPO (Anti-Thyroid Peroxidase Antibody) test measures the level of antibodies directed against thyroid peroxidase (TPO), an enzyme that plays a critical role in the production of thyroid hormones (T3 and T4). In autoimmune thyroid diseases, the immune system mistakenly produces antibodies that attack TPO, leading to inflammation and impaired thyroid function.
This test is primarily used to diagnose and monitor autoimmune thyroid conditions such as Hashimoto’s thyroiditis (the most common cause of hypothyroidism) and Graves’ disease (a common cause of hyperthyroidism). It is also used in the evaluation of unexplained hypothyroid or hyperthyroid symptoms, recurrent miscarriage, and thyroid nodules.
