​Thyroid Peroxidase Antibody (Thyroperoxidase Antibody, TPO)
Produced by: Lymphocytes (white blood cells).
Purpose: See below.
Definition: Thyroperoxidase Antibodies are produced by white blood cells that come in contact and circulate within the thyroid gland causing an abnormal autoimmune reaction against Thyropreoxidase (TPO). Thyroperoxidase (TPO) is an enzyme used by the thyroid gland for the synthesis of thyroid hormones.
Lab Reference Range: <9 IU/mL
When to order:
- With initial screening for hypo or hyperthyroidism
- When you have an enlarged thyroid gland (goiter) or a nodule on the thyroid gland.
- To initially screen for Graves’ Disease or Hashimoto’s Thyroiditis
- To monitor the treatment and progression or reversal of the disease.
Pearls:
Thyroperoxidase (TPO) and Thyroperoxidase Antibody (TPO Antibody) are two different things. The former is an enzyme normally produced by the thyroid gland. The latter is an autoantibody produced by local white blood cells causing an abnormal autoimmune reaction that slowly destroys the thyroid gland through an inflammatory process.
Half-life: Approximately 26 days.
Causes of elevated TPO Antibodies are an autoimmune reaction associated with the thyroid gland; Hashimoto’s Thyroiditis and Graves ’ Disease.
TPO Antibody levels can be used to assess the degree of disease activity. The higher the number the more active the disease.
TPO Antibodies cause damage to the thyroid gland through complement activation and antibody dependent cell cytotoxicity.
Webinar Jam Session on how to treat Hashimoto's & Grave's