High thyroid peroxidase antibodies indicate that the patient has an autoimmune disorder such as Graves' disease or Hashimoto's disease, according to Mayo Clinic. Most people who are diagnosed with thyroid disease typically are asked to undergo a thyroid peroxidase antibody test.
For those who have autoimmune disorders, the immune system produces antibodies that begin to attack the normal tissues in the body, states Mayo Clinic. These antibodies also attack the thyroid gland that leads to inflammation and diminished function of the gland. Keep in mind, however, that the presence of these antibodies doesn't always mean a patient has an autoimmune disorder. They are simply a good indication of it, and a doctor usually orders more tests to find out. For those who have a thyroid that functions normally, yet have elevated thyroid peroxidase levels, a doctor usually suggests periodic blood work to monitor thyroid function.
A doctor might also order a test for thyroid peroxidase antibodies in women who are pregnant and also been diagnosed with an autoimmune disease, claims Mayo Clinic. This is especially the case when it is Grave's disease or Hashimoto's disease. In this case, the doctor performs the thyroid peroxidase early in pregnancy and again later in pregnancy to determine if the baby is at risk of similar conditions.