TPO Ab
Antibodies against the thyroid enzyme TPO — the primary marker for autoimmune thyroid disease.
What is it
TPO antibodies are immune system antibodies that target thyroid peroxidase, an enzyme involved in thyroid hormone production. Elevated levels are a primary marker of autoimmune thyroid disease.
Why it's measured
TPO antibodies have been associated with Hashimoto's thyroiditis and other autoimmune thyroid conditions in published research.
Reference range
Standard laboratory reference
< 35 IU/mL
Reference ranges vary by laboratory. Your individual reference range will appear on your test report and should be interpreted by your physician in the context of your overall health profile.
What results may indicate
Elevated
Has been associated with autoimmune thyroid disease, including Hashimoto's, in published research.
Lower
Is generally considered favorable.
These associations are general. They are not a personal diagnosis or prediction. Discuss your individual results with your physician in the context of your full health profile.
When it's measured
Used in evaluating autoimmune thyroid disease, particularly when TSH is abnormal or symptoms persist.
Related markers
Measured in
A complete look at your heart, hormones, metabolism, inflammation, and longevity systems — drawn at Quest or LabCorp, reviewed by a U.S.-licensed physician.
Explore the Apex Panel →This information is for general educational purposes only and is not medical advice. Lab results alone are not intended to diagnose, treat, or cure any condition and do not replace the advice of a healthcare provider. OPTML does not offer medical advice, a diagnosis, medical treatment, or any form of medical opinion.