ATPO | Antibodies against Thyroid Peroxidase

Antithyroid Peroxidase (ATPO) – is one of the most important laboratory indicators of autoimmune thyroid diseases. ATPO – are antibodies directed against the thyroid enzyme – thyroid peroxidase, which is essential for the synthesis of thyroid hormones. Increased levels of ATPO indicate an autoimmune inflammatory process, which can eventually lead to thyroid dysfunction – usually hypothyroidism.

The ATPO test is often performed together with antibodies against thyroglobulin (anti-TG) and is particularly important for the early diagnosis of Hashimoto's thyroiditis. Even with normal TSH or FT4 levels, increased ATPO levels allow suspicion of an emerging autoimmune process before clinical symptoms of hypothyroidism appear. The test also helps determine the etiology of the disease and avoid unnecessary surgical interventions when thyroid nodules are assessed together with cytological aspirate examination.

An increase in ATPO concentration can also be observed in postpartum thyroid diseases (i.e., postpartum thyroiditis).

Test principle: ATPO antibodies are determined by immunochemical method from venous blood. The test is often performed together with TSH, FT4, and anti-TG to evaluate the complete thyroid condition.

Recommendations:

• Recommended for patients suspected of autoimmune thyroid disease.
• Useful for early diagnosis of Hashimoto's thyroiditis.
• Performed to assess the likelihood of postpartum thyroiditis.
• Prescribed for patients with nodular changes when planning or evaluating the need for surgical treatment.
• The test is also important for differentiating the origin of thyroid disease in cases of hypothyroidism or hyperthyroidism.
• It is recommended to come for the test fasting for at least 12 hours.