TPO Antibodies Test: Detecting Autoimmune Thyroid Disease
Thyroid peroxidase (TPO) is an enzyme essential for the production of thyroid hormones. When the immune system mistakenly produces antibodies against TPO, it can lead to chronic inflammation, tissue damage, and disrupted thyroid function. Anti-TPO antibodies are the hallmark of autoimmune thyroid disease and are found in the vast majority of Hashimoto's thyroiditis cases and a significant proportion of Graves' disease patients.
Why Test TPO Antibodies?
TPO antibody testing is crucial for determining whether a thyroid condition has an autoimmune origin. It is recommended when thyroid function tests are abnormal, when you have symptoms despite normal TSH and T4, during pregnancy (about 20% of pregnant women have elevated TPO antibodies unknowingly), and if you have a personal or family history of autoimmune or thyroid disorders. Tracking antibody levels over time can also help monitor disease progression and response to treatment.
What Do High TPO Antibodies Levels Mean?
A positive (elevated) TPO antibody result indicates that the immune system is producing antibodies against the thyroid. The higher the level, the more likely an autoimmune thyroid disorder is present. Hashimoto's thyroiditis is the most common association, typically presenting with hypothyroidism (high TSH, low-to-normal T4 and T3). Elevated TPO antibodies may also appear in Graves' disease and other autoimmune conditions.
What Do Low TPO Antibodies Levels Mean?
A negative or low TPO antibody result means antibodies were not detected at clinically significant levels at the time of testing. This makes autoimmune thyroid disease less likely but does not completely rule it out, as some patients with autoimmune thyroiditis do not produce detectable antibodies. Retesting may be warranted if symptoms persist.
Symptoms to Watch For
- Fatigue and general weakness
- Weight gain and difficulty losing weight
- Feeling cold and having cold extremities
- Dry skin and thinning hair
- Constipation
- Puffy face and hoarseness
- Muscle stiffness and joint pain
- Depression and memory problems
- Menstrual irregularities
Who Should Get Tested?
- Anyone diagnosed with a thyroid disorder to check for autoimmune origin
- People with thyroid symptoms despite normal function tests
- Pregnant women or those planning pregnancy
- Individuals with a family history of autoimmune or thyroid disease
- Those monitoring known autoimmune thyroiditis
How to Prepare for Your Test
No preparation is required for this test. Bring valid identification to your appointment. If you take a supplement containing biotin (often sold for hair and nails), pause it for two days before the test, as high doses can distort the result.
Order Your Blood Test
Test your TPO Antibodies levels with an accredited Swedish laboratory. Results within days, reviewed by Wellth.
Frequently Asked Questions
What is the difference between TPO antibodies and TG antibodies?
Can TPO antibodies be positive without thyroid dysfunction?
Can lifestyle changes reduce TPO antibody levels?
Why test TPO antibodies during pregnancy?
Reviewed by
Wellth Team
Wellth
Our content is written and reviewed by Wellth, and fact-checked against peer-reviewed research and current Swedish clinical guidelines.
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The information on this page is provided for informational purposes only and does not constitute professional medical advice, diagnosis, or treatment. Wellth provides health information and testing services but is not a substitute for clinical care. Always consult a qualified healthcare provider if you have questions about a medical condition. If you are experiencing severe or urgent symptoms, contact your doctor or call 1177 Vårdguiden. Blood test results should be interpreted by a qualified healthcare professional in the context of your complete medical history.