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HelpTest Code TPO Thyroperoxidase Antibodies, Serum
Additional Codes
Thyroid Microsomal Antibody
Reporting Name
Thyroperoxidase Ab, SUseful For
Aiding in the diagnosis of thyroid autoimmune disorders
Differentiating thyroid autoimmune disorders from nonautoimmune goiter or hypothyroidism
As a diagnostic tool in deciding whether to treat a patient who has subclinical hypothyroidism
Performing Laboratory
Mayo Clinic Laboratories in Rochester
Specimen Type
Serum RedSpecimen Required
Patient Preparation: For 12 hours before specimen collection, patient should not take multivitamins or dietary supplements (eg, hair, skin, and nail supplements) containing biotin (vitamin B7).
Supplies: Sarstedt 5 mL Aliquot Tube (T914)
Collection Container/Tube: Red top
Submission Container/Tube: Plastic vial
Specimen Volume: 0.6 mL serum
Collection Instructions: Within 2 hours of collection, centrifuge and aliquot serum into plastic vial.
Specimen Minimum Volume
Serum: 0.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Serum Red | Refrigerated (preferred) | 7 days |
| Frozen | 30 days | |
| Ambient | 7 days |
Special Instructions
Reference Values
<9.0 IU/mL
Reference values apply to all ages.
Day(s) Performed
Monday through Saturday
Test Classification
This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.CPT Code Information
86376
LOINC Code Information
| Test ID | Test Order Name | Order LOINC Value |
|---|---|---|
| TPO | Thyroperoxidase Ab, S | 8099-4 |
| Result ID | Test Result Name | Result LOINC Value |
|---|---|---|
| TPO | Thyroperoxidase Ab, S | 8099-4 |
Interpretation
Values above 9.0 IU/mL are generally associated with autoimmune thyroiditis, but elevations are also seen in other autoimmune diseases.
In patients with subclinical hypothyroidism, the presence of thyroperoxidase (TPO) antibodies predicts a higher risk of developing overt hypothyroidism, 4.3% per year versus 2.1% per year in antibody-negative individuals. Furthermore, it raises the concern that such patients may be at increased risk of developing other autoimmune diseases, such as adrenal insufficiency and type 1 diabetes.
The frequency of detectable anti-TPO observed in nonimmune thyroid disease is similar to the 10% to 12% observed in a healthy population with normal thyroid function.
There is a good association between the presence of autoantibodies against TPO and histological thyroiditis. However, in view of the extensive regenerative capacity of the thyroid under the influence of thyrotropin, chronic thyroid disease may be present for years before the clinical manifestation of hypothyroidism becomes evident, if ever.
Clinical Reference
1. Feldt-Rasmussen U. Analytical and clinical performance goals for testing autoantibodies to thyroperoxidase, thyroglobulin, and thyrotropin receptor. Clin Chem. 1996;42(1):160-163
2. Gharib H, Tuttle RM, Baskin HJ, et al. Consensus Statement #1: Subclinical thyroid dysfunction: a joint statement on management from the American Association of Clinical Endocrinologists, the American Thyroid Association, and the Endocrine Society. Thyroid. 2005;15(1):24-28. doi:10.1089/thy.2005.15.24
3. Frohlich E, Wahl R. Thyroid Autoimmunity: Role of Anti-thyroid Antibodies in Thyroid and Extra-Thyroidal Diseases. Front Immunol. 2017;8:521. Published 2017 May 9. doi:10.3389/fimmu.2017.00521
4. Freedman DB, Halsall D, Marshall WJ, Ellervik C. Thyroid disorders. In: Rifai N, Horvath AR, Wittwer CT: eds. Tietz Textbook of Clinical Chemistry and Molecular Diagnostics. 6th ed. Elsevier; 2018:1572-1616
Report Available
1 to 3 daysMethod Name
Chemiluminometric Immunoassay
Testing Algorithm
For more information, see Thyroid Function Ordering Algorithm
Aliases:
Thyroid Antibodies