Which test is most useful to confirm Graves' disease?

Which test is most useful to confirm Graves' disease?

• A. TSH receptor antibodies
• B. TSH
• C. Free T4
• D. Thyroglobulin

Answer: (A)

Graves' disease causes hyperthyroidism through autoantibodies that stimulate the TSH receptor. The test that most clearly confirms this mechanism is measurement of TSH receptor antibodies (also known as thyroid-stimulating immunoglobulins or TRAb). A positive TRAb result directly demonstrates the autoimmune stimulation of the receptor that drives Graves', making it the most specific and confirmatory test. If you just look at TSH, it would be suppressed in Graves', but that can occur with other forms of hyperthyroidism as well. Free T4 gives information about the level of thyroid hormone but doesn’t prove Graves' as the cause. Thyroglobulin is a general thyroid gland protein and can be influenced by various thyroid conditions or procedures, so it isn’t a diagnostic marker for Graves' disease.

Graves' disease causes hyperthyroidism through autoantibodies that stimulate the TSH receptor. The test that most clearly confirms this mechanism is measurement of TSH receptor antibodies (also known as thyroid-stimulating immunoglobulins or TRAb). A positive TRAb result directly demonstrates the autoimmune stimulation of the receptor that drives Graves', making it the most specific and confirmatory test.

If you just look at TSH, it would be suppressed in Graves', but that can occur with other forms of hyperthyroidism as well. Free T4 gives information about the level of thyroid hormone but doesn’t prove Graves' as the cause. Thyroglobulin is a general thyroid gland protein and can be influenced by various thyroid conditions or procedures, so it isn’t a diagnostic marker for Graves' disease.