Hashimoto’s symptoms despite thyroxine replacement is a complex and heavily requested topic that is not completely understood. Before diving into this, it’s important to discuss Hashimoto’s Disease (HD) and the role of antibodies.
What is Hashimoto’s Disease?
Hashimoto’s Disease causes low thyroid function due to the destruction of the thyroid gland by T-lymphocytes. This condition is associated with antibodies against proteins within the thyroid, specifically anti-thyroid peroxidase and anti-thyroglobulin. These antibodies are more markers of the disease rather than direct causes of thyroid damage.
Interestingly, while the presence of these antibodies is diagnostic for HD, there is not strong evidence that the levels of these antibodies correlate with the likelihood of developing low thyroid function, especially in the case of anti-thyroglobulin. This is significant because around 20% of the population has these antibodies, but only 1-5% develop hypothyroidism.
Associations with Other Conditions
Hashimoto’s antibodies are also linked to other conditions and diseases, particularly other autoimmune conditions and fertility issues. The same gene associated with Hashimoto’s is related to coeliac disease and other endocrine conditions like type 1 diabetes, pernicious anemia, or Addison’s disease. This is due to the shared genetic predisposition to autoimmune diseases rather than the specific antibodies themselves.
Thyroid antibodies are also associated with an increased risk of fertility issues and recurrent miscarriage, with a 2-3 times higher risk. Initially, it was thought this was due to decreased thyroid hormone reserve, but several studies have shown that supplementing with thyroxine in HD with normal TSH does not improve fertility outcomes. Therefore, it is more likely due to autoimmune factors directly related to the antibodies or their association with other conditions. Research in this area is ongoing.
Key Takeaways
Thyroid antibodies are common, and their exact significance and role in disease are not completely known. They are useful for diagnosing certain conditions, such as low thyroid function or infertility. However, the presence of antibodies is more important than their levels. Consequently, testing without a specific reason or frequent monitoring of antibodies may cause more anxiety rather than positive outcomes or changes in management.