Which finding would be significant in Graves disease?

Which finding would be significant in Graves disease?

• A. Increases TSH levels
• B. Antibody to TSHR
• C. Decreased T3 and T4
• D. Antithyroglobulin antibody

Answer: (B)

Graves disease is driven by autoimmune stimulation of the TSH receptor. The most significant finding is antibodies directed against the TSH receptor, which bind and activate the receptor on thyroid cells. This pushes the thyroid to produce and release more thyroid hormones (T3 and T4), leading to hyperthyroidism. Because of the excess hormones, the pituitary senses this and suppresses TSH, so TSH levels are typically low. That’s why the antibody to the TSH receptor is the best answer. Increases in TSH would not fit Graves, since TSH is typically reduced. Decreased T3 and T4 would contradict the hyperthyroid state. Antithyroglobulin antibodies can be present in various autoimmune thyroid diseases but are not the defining feature of Graves.

Graves disease is driven by autoimmune stimulation of the TSH receptor. The most significant finding is antibodies directed against the TSH receptor, which bind and activate the receptor on thyroid cells. This pushes the thyroid to produce and release more thyroid hormones (T3 and T4), leading to hyperthyroidism. Because of the excess hormones, the pituitary senses this and suppresses TSH, so TSH levels are typically low.

That’s why the antibody to the TSH receptor is the best answer. Increases in TSH would not fit Graves, since TSH is typically reduced. Decreased T3 and T4 would contradict the hyperthyroid state. Antithyroglobulin antibodies can be present in various autoimmune thyroid diseases but are not the defining feature of Graves.