What are anti-TPO antibodies (TPO-AB)?
Thyroid autoantibodies develop when a person's immune system mistakenly targets parts of the thyroid gland or thyroid proteins, leading to chronic inflammation of the thyroid (thyroiditis), tissue damage, and/or disruption of thyroid function. Many people suffer from autoimmune thyroiditis.
Thyroid antibody tests are primarily ordered to help detect an autoimmune thyroid disease and to distinguish it from other forms of thyroid dysfunction.
An anti-TPO test measures levels of thyroid peroxidase antibodies (also known as TPO-antibodies). It detects the presence of thyroid antibodies usually associated with hypothyroidism (low thyroid hormone production) and is an important part of a full thyroid panel for someone with symptoms of thyroid disease. Hashimoto’s is the most common cause of hypothyroidism and the most common thyroid disorder.
Why test anti-TPO antibodies (TPO-AB)?
Testing TPO antibodies is helpful if you have or suspect a thyroid disorder to determine if you also have an autoimmune disease or to monitor your antibody levels. It may be important even if you have symptoms despite normal thyroid function test results. During pregnancy, 20% of women may have elevated TPO antibodies without knowing it, increasing the need for screening. Regular testing helps identify risk factors for lifestyle diseases, especially if you have a personal or family history of thyroid disorders.
What does it mean if my thyroid antibody test is negative?
Negative results mean that thyroid autoantibodies are not present in the blood at the time of testing. Some people who have autoimmune thyroid disease do not have autoantibodies. Repeat testing at a later date can be done if symptoms persist.
What does it mean if my thyroid antibody test is positive?
The presence of thyroid antibodies suggests that you have an autoimmune thyroid disorder. The higher the level, the more likely this is. In this case we will refer you to your doctor and can continue to work with you to make lifestyle and dietary changes that will help.
More Information
Reference ranges may vary between laboratories. If you plan to order this test regularly for monitoring purposes, it is best to have it done by the same laboratory each time, using the same methodology.
Preparations for this test
No preparation is required for this test.
On the day of the test
Always take I.D. with you when going to take a test.