From the Guidelines
Thyroid stimulating immunoglobulins (TSIs) should be tested for in patients with suspected Graves' disease, as they are the primary cause of this condition, and their presence can help diagnose and monitor disease activity 1. When evaluating patients with thyrotoxicosis, it is essential to distinguish between thyroiditis and Graves' disease, as the treatment approaches differ. Thyroiditis is often self-limiting and may lead to permanent hypothyroidism, whereas Graves' disease requires specific treatment to manage the condition. Some key points to consider when evaluating TSIs include:
- TSIs mimic the action of TSH, causing excessive thyroid hormone production 1
- Testing for TSIs is valuable for diagnosing Graves' disease, particularly in patients with hyperthyroid symptoms, goiter, or eye abnormalities 1
- TSI levels can help monitor disease activity and predict relapse after treatment 1
- Normal individuals do not have detectable TSIs, so their presence is diagnostically significant 1
- Treatment for conditions involving TSIs typically includes anti-thyroid medications, radioactive iodine therapy, or thyroidectomy 1
- Teprotumumab, a human monoclonal antibody inhibitor of IGF-IR, has been shown to attenuate the actions of IGF-I, thyrotropin, thyroid-stimulating immunoglobulins, and immunoglobulins in patients with Graves’ disease, reducing proptosis and the clinical activity score of disease in many with active disease 1
From the Research
Thyroid Stimulating Immunoglobulins
- Thyroid stimulating immunoglobulins are antibodies that stimulate the thyroid gland, leading to hyperthyroidism in patients with Graves' disease 2.
- The presence of these immunoglobulins is well established, and their causative role in hyperthyroidism is widely recognized 2.
- The use of human specific stimulation assays has helped to identify patients with thyroid stimulating immunoglobulins, even if they are negative for long-acting-thyroid-stimulator (LATS) 2.
Diagnosis and Management of Graves' Disease
- Thyroid stimulating immunoglobulins (TSI) and TSH-receptor antibodies (TRAb) are both used in the diagnosis and management of Graves' disease 3.
- TSI is a relatively new method for assessing TSH-receptor antibodies function, and it has been shown to be correlated with TRAb in patients with Graves' disease 3.
- The levels of TSI and TRAb can be used to predict the risk of relapse in patients with Graves' disease, with higher levels indicating a higher risk of relapse 3, 4.
Prognostic Value of Thyroid Stimulating Immunoglobulins
- Thyroid stimulating immunoglobulins have been shown to be a good predictor of relapse in patients with Graves' disease treated with anti-thyroid drugs 4.
- The odds ratio of positive thyroid stimulating immunoglobulins for the risk of relapse was 33.271, indicating a strong association between the two 4.
- It has been suggested that it may be safer to discontinue anti-thyroid drugs when thyroid stimulating immunoglobulins and thyroid receptor antibody are both negative 4.
Treatment of Graves' Disease
- High doses of antithyroid drugs, such as methimazole, can decrease the levels of thyroid stimulating antibodies and antithyroid microsomal antibodies in patients with Graves' disease 5.
- Hypothyroidism during antithyroid drug treatment with methimazole has been shown to be a favorable prognostic indicator in patients with Graves' disease, with a higher percentage of patients in remission at 6,12, and 24 months after discontinuation of treatment 6.