Thyroid Peroxidase Antibodies

This test measures thyroid peroxidase (TPO) antibodies, proteins your immune system may produce when it mistakenly targets your thyroid. Your thyroid helps regulate metabolism, energy, and body temperature. TPO antibody testing can help identify an autoimmune cause of thyroid problems, especially Hashimoto’s disease. These antibodies may also be present in Graves’ disease. TPO antibodies can help identify an autoimmune cause of thyroid problems, especially Hashimoto’s disease. They may also be present in Graves’ disease. Your provider may recommend this test if you have abnormal thyroid results or symptoms such as fatigue, unexplained weight changes, constipation, or sensitivity to cold.