Anti Thyroperoxidase Antibody
What is Anti-TPO?
Anti thyroperoxidase antibody (TPO) are seen in thyroid diseases. The anti TPO antibody test measures the levels of antibodies directed against thyroid peroxidase, an enzyme found in the thyroid gland. This enzyme plays an important role in the production of thyroid hormones. This test is also known as thyroid peroxidase (TPO) antibody (TPOAb) test, thyroid peroxidase autoantibody test, the antimicrosomal antibody test, and antithyroid microsomal antibody test. The presence of these antibodies would help in diagnosing the reason for low levels of thyroid hormones.
Why is Anti-TPO done?
To diagnose autoimmune disorders of thyroid like Hashimoto's thyroiditis (swelling of thyroid gland resulting in decreased thyroid function), Grave's disease (overactive thyroid gland resulting in overproduction of thyroid hormones) or idiopathic myxedema (associated with low levels of thyroid hormones)
To differentiate between autoimmune disorders of thyroid from non-autoimmune disorders such as goiter or hypothyroidism.
To diagnose chronic thyroiditis
To diagnose subclinical hypothyroidism
What does Anti-TPO Measure?
TPO is also known as thyroid peroxidase or iodide peroxidase which is an enzyme mainly expressed in the thyroid gland. The thyroid gland is positioned at the lower part of the neck. TPO is found in the cells of the thyroid follicle where it helps in the production of the thyroid hormones. Its basic function is to oxidize iodide ions to form iodine atoms which assist in the production of thyroxine (T4) or triiodothyronine (T3), the thyroid hormones. TPO is an antigenic determinant of autoantibodies in diseases like autoimmune disorders of the thyroid. These antibodies are called as anti-TPO antibodies (anti-Thyroid peroxidase antibodies) which activates complement and might be associated with dysfunction of thyroid and its pathogenesis. To assess these antibodies, Anti-TPO antibody test is carried out.
Interpreting Anti-TPO results
Positive tests may indicate the following:
- Hashimoto’s thyroiditis
- Grave’s disease
- Idiopathic Myxedema
- Postpartum thyroiditis
- Nontoxic Nodular Goiter
- Thyroid cancer
Answers to Patient Concerns & Frequently Asked Questions (FAQs) about Anti-TPO
Frequently Asked Questions about Anti Thyroperoxidase Antibody