The Monitoring of Thyroid Peroxidase (TPO)
Thyroid peroxidase (TPO) is an enzyme found in the thyroid gland. It has an important role in the production of thyroid hormones: it catalyzes the iodination of thyroglobulin and is involved in the coupling of the iodotyrosines to form free T3 or free T4.
In some disease states, people develop antibodies to thyroid peroxidase. These antibodies attack the thyroid gland and damage its function. Thyroid peroxidase antibodies are seen in all thyroid autoimmune diseases, and the highest levels are most commonly seen in Hashimoto's thyroiditis. The existence of anti-TPO can be an indicator of developing thyroiditis: patients with a positive TPO antibody test may have symptoms of a thyroid imbalance, yet all other thyroid test levels may appear normal. Elevated concentrations of anti-TPO are also seen in patients with thyroid cancer. Another useful application of TPO testing is in polycystic ovary syndrome (PCOS). Women with PCOS often have a greater occurrence of TPO antibodies; one study shows elevated TPO antibodies in 27% of women with PCOS.¹
Canary Club offers many testing options to help you identify the conditions mentioned above.
The menu includes FT3, FT4, and TSH, which combined with an anti-TPO reflects thyroid function. In addition, our salivary test menu includes hormones that, combined with a serum anti-TPO, can help identify PCOS (testosterone, DHEA, estradiol, and progesterone).
¹ "High Prevalence of Autoimmune Thyroiditis in Patients With Polycystic Ovary Syndrome". Janssen et.al Eur.Jour.Endo. (2004) 150 363-369.