Thyroid Peroxidase Test (cont.)

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What is the thyroid peroxidase test?

Thyroid peroxidase test is a test that measures the level of an antibody that is directed against thyroid peroxidase (TPO).

Autoantibodies to thyroid peroxidase (TPOAb) are produced within the body. The presence of TPOAb in the blood reflects a prior attack on the thyroid tissue by the body's immune system.

What does a positive thyroid peroxidase test mean?

  • Most people with chronic thyroiditis (70%-90%) display a positive TPO test. The test is also positive in lesser numbers of people with other thyroid diseases.
  • Other autoimmune disorders that may cause a positive TPOAb test include:
  • About 3% of people with a positive TPOAb test show no evidence of disease.
  • The chance of having a positive TPOAb test is greater in females and increases with age.

What are other names for thyroid peroxidase test?

This test goes by a confusing number of names, including:

  • thyroid peroxidase (TPO) antibody (TPOAb) test,
  • thyroid peroxidase autoantibody test,
  • antimicrosomal antibody test, and
  • antithyroid microsomal antibody test.

Previous contributing author: Frederick Hecht, MD, FAAP

Medically reviewed by John A. Seibel, MD; Board Certified Internal Medicine with a subspecialty in Endocrinology & Metabolism

REFERENCE:

"Laboratory assessment of thyroid function"
uptodate.com


Medically Reviewed by a Doctor on 2/4/2014

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Thyroid Peroxidase Test - Diagnosis Question: Were you diagnosed with an autoimmune or other type of disorder from your thyroid peroxidase results? Please explain.