When to check Thyroid Stimulating Hormone (TSH) antibodies?

From the Guidelines

Thyroid stimulating antibodies (TSAb) should be checked in patients with suspected Graves' disease, particularly those presenting with hyperthyroidism and specific clinical features such as ophthalmopathy, pretibial myxedema, or thyroid acropachy, as well as in pregnant women with hyperthyroidism or a history of Graves' disease, as indicated by the most recent guidelines 1.

Key Considerations

• The presence of TSAb indicates an autoimmune process that can cause excessive thyroid hormone production, and high titers generally correlate with disease severity and risk of relapse after treatment.
• Testing for TSAb is valuable when the diagnosis of hyperthyroidism is unclear, when distinguishing between different causes of hyperthyroidism, or when monitoring disease activity in patients with known Graves' disease.
• The 2021 guidelines from the Journal of Clinical Oncology suggest considering TSH receptor antibody testing if there are clinical features and suspicion of Graves’ disease, such as ophthalmopathy and T3 toxicosis 1.

Clinical Scenarios

• In patients with suspected Graves' disease, TSAb testing can help confirm the diagnosis and guide treatment decisions.
• In pregnant women with hyperthyroidism or a history of Graves' disease, TSAb testing can help assess the risk of neonatal thyrotoxicosis.
• In patients with known Graves' disease, periodic TSAb testing can help monitor disease activity and guide therapeutic decisions about medication dosing or duration.

Evidence-Based Recommendations

• The most recent guidelines from the Journal of Clinical Oncology provide evidence-based recommendations for the management of thyroid dysfunction in patients treated with immune checkpoint inhibitor therapy, including the use of TSAb testing in certain clinical scenarios 1.
• The guidelines emphasize the importance of considering clinical features and suspicion of Graves’ disease when deciding whether to test for TSAb.
• The guidelines also provide recommendations for the management of thyrotoxicosis, including the use of beta-blockers, hydration, and supportive care, as well as the consideration of endocrine consultation and medical thyroid suppression in certain cases.

From the Research

Thyroid Stimulating Antibodies

• Thyroid stimulating antibodies (TSAb) are a key factor in the diagnosis and management of Graves' disease, a common cause of hyperthyroidism 2, 3, 4, 5, 6.
• The presence of TSAb can be detected through laboratory tests, and their levels can be used to monitor the effectiveness of treatment 3.
• TSAb can stimulate the thyroid gland to produce excess thyroid hormones, leading to hyperthyroidism 5.

When to Check Thyroid Stimulating Antibodies

• TSAb should be checked in patients with suspected Graves' disease or hyperthyroidism, particularly if they have symptoms such as tachycardia, anxiety, or tremors 2, 4.
• TSAb levels can be used to monitor the response to treatment with antithyroid medications, radioactive iodine, or surgery 3, 6.
• In patients with Graves' disease, TSAb levels can be used to predict the risk of relapse after treatment 6.

Clinical Significance of Thyroid Stimulating Antibodies

• Elevated TSAb levels are associated with an increased risk of hyperthyroidism and its complications, such as cardiovascular disease and osteoporosis 2, 6.
• TSAb can also stimulate the growth of thyroid tissue, leading to the development of goiter or thyroid nodules 5.
• The presence of TSAb can be used to distinguish Graves' disease from other causes of hyperthyroidism, such as toxic multinodular goiter or thyroiditis 2, 4.