Strategies to Reduce Anti-TPO Antibody Levels
There is no single definitive treatment proven to reduce anti-TPO antibody levels, but selenium supplementation shows the most promising evidence for reducing thyroid autoantibodies in patients with autoimmune thyroiditis.
Selenium Supplementation
- Selenium supplementation at 200 μg daily has shown significant reduction in thyroid peroxidase antibody (TPOAb) concentrations in adults with autoimmune thyroiditis 1, 2
- In LT4-treated populations, selenium supplementation resulted in significantly lower TPOAb levels after three months (WMD = -271 IU/mL), with consistent results at six and twelve months 1
- In untreated autoimmune thyroiditis patients, selenium supplementation showed a decrease in TPOAb levels after three months (WMD = -512 IU/mL) 1
- Some studies report complete normalization of antibody concentrations in selenium-treated patients compared to placebo groups 2
Limitations and Contradictory Evidence
- Not all studies show benefit - some research demonstrates no immunological benefit of selenium in consecutive patients with autoimmune thyroiditis 3
- Selenium supplementation does not appear to decrease TPOAb concentrations in children and adolescents with autoimmune thyroiditis 4
- The quality of evidence for selenium supplementation in Hashimoto's thyroiditis is generally assessed as low 1, 5
- Selenium supplementation carries a significantly higher risk of reporting adverse effects compared to controls 1
Potential Immune Modulation Mechanisms
- Selenium-dependent glutathione peroxidase activity within thyroid cells may protect against thyroiditis 2
- Selenium-dependent enzymes have several modifying effects on the immune system that may help reduce autoimmunity 2
- Even mild selenium deficiency may contribute to the development and maintenance of autoimmune thyroid diseases 2
Other Considerations
- Thyroiditis is often a self-limiting process that can lead to permanent hypothyroidism after the thyrotoxic phase 6
- In patients with thyroid dysfunction due to immune checkpoint inhibitors, thyroid hormone replacement is the standard treatment for resulting hypothyroidism 6
- Testing for thyroid antibodies such as TPO is warranted in patients with symptoms of hypothyroidism and abnormal thyroid function tests 6
Monitoring Recommendations
- Monitor thyroid function tests (TSH, free T4) regularly during treatment 6
- Follow TPOAb levels to assess response to interventions 1, 2
- Ultrasound of the thyroid may show normalized echogenicity in patients with reduced antibody concentrations 2
Clinical Implications
- While selenium may reduce antibody levels, the clinical relevance of this reduction remains unclear 5
- The primary treatment for hypothyroidism resulting from autoimmune thyroiditis remains thyroid hormone replacement therapy 6
- Patients with both adrenal insufficiency and hypothyroidism should always start steroids prior to thyroid hormone to avoid an adrenal crisis 6