The laboratory test detects the amount of anti-thyroid peroxidase autoantibody in the blood.
Anti-TPO testing is recommended in all cases where TSH, T4 and T3 levels are abnormal. The result of the test can help to determine the cause of the thyroid dysfunction and to design the appropriate medication.
Determination of anti-TPO levels may also be necessary in pregnancy, especially when there is a diagnosis of autoimmune disease (e.g. Hashimoto’s or Graves-Basedow disease).