Thyroid Peroxidase (TPO) Antibody
CPT Code(s):
86376
Turnaround Time:
24 - 72 hours
Specimen Requirements
Preferred Specimen:
Serum
Minimum Volume:
1.0 mL
Transport Container:
Serum Separator Tube (SST) or Red Top Tube
Transport Temperature:
Room Temperature
Collection Instructions:
Separate serum from cells within one hour of collection. Transfer to a plastic transport tube before shipping. To avoid delays in turnaround time when requesting multiple tests on frozen samples, please submit separate frozen specimens for each test requested.
Rejection Criteria:
Grossly hemolyzed; bacterial contamination; lipemic specimen; icteric specimen; non - serum specimen types
Stability Criteria
Room Temperature:
8 hours
Refrigerated:
48 hours
Frozen:
30 days
Clinical Significance
The Thyroid Peroxidase Antibody (TPOAb) test is a diagnostic tool used to detect the presence of antibodies against thyroid peroxidase, an enzyme involved in the production of thyroid hormones. This test has specific clinical significance and diagnostic use in the following ways:
1. Autoimmune Thyroid Diseases: TPOAb is primarily used to aid in the diagnosis of autoimmune thyroid diseases, such as Hashimoto's thyroiditis and Graves' disease. These conditions are characterized by an abnormal immune response against the thyroid gland, leading to inflammation and dysfunction. The presence of TPO antibodies is a hallmark of autoimmune thyroid diseases, and their detection helps differentiate these conditions from other thyroid disorders.
2. Confirming Hashimoto's Thyroiditis: Hashimoto's thyroiditis is the most common cause of hypothyroidism, and TPOAb is often used to confirm the diagnosis. Elevated levels of TPO antibodies indicate an autoimmune attack on the thyroid gland, leading to impaired thyroid function. This information guides the appropriate management and treatment of the condition.
3. Predicting Future Thyroid Dysfunction: The presence of TPO antibodies in individuals without overt thyroid dysfunction can indicate an increased risk of developing thyroid disorders in the future. Patients with TPO antibodies but normal thyroid hormone levels may be monitored more closely to detect early signs of thyroid dysfunction and initiate timely interventions.
4. Pregnancy and Fertility: TPO antibodies can also have implications for pregnant women. High levels of TPO antibodies during pregnancy, particularly in the first trimester, are associated with an increased risk of miscarriage, preterm birth, and maternal postpartum thyroiditis. Testing for TPO antibodies in pregnant women helps identify those at higher risk and allows for appropriate monitoring and management.
5. Monitoring Disease Progression and Treatment Response: TPOAb levels can be monitored over time to assess the progression of autoimmune thyroid diseases and the effectiveness of treatment interventions. A reduction in TPOAb levels may indicate a positive response to therapy, while persistently elevated levels could suggest ongoing immune activity and the need for adjustments in treatment.
In summary, the Thyroid Peroxidase Antibody (TPOAb) test has clinical significance and diagnostic use in the diagnosis of autoimmune thyroid diseases, particularly Hashimoto's thyroiditis. It helps differentiate autoimmune thyroid conditions from other thyroid disorders, predicts future thyroid dysfunction, guides management during pregnancy, and monitors disease progression and treatment response. By detecting the presence of TPO antibodies, this test provides valuable information for healthcare providers in evaluating thyroid health, developing appropriate treatment strategies, and optimizing patient care.