Question

A patient has hyperthyroidism with low RAI uptake - what do you measure next, and what does the result tell you?

a) Measure TSH receptor antibodies; if positive, confirms Graves' disease
b) Measure free T3 levels; if elevated, indicates secondary hyperthyroidism
c) Measure anti-thyroid peroxidase antibodies; if positive, indicates Hashimoto's thyroiditis
d) Measure serum thyroglobulin levels; if elevated, suggests thyroid cancer

Answer 1

To determine the cause of hyperthyroidism with low RAI uptake, measuring TSH receptor antibodies can help confirm the presence of Graves' disease.

Step-by-step explanation:

If a patient has hyperthyroidism with low Radioactive Iodine (RAI) uptake, the next step would be to measure TSH receptor antibodies. This is to ascertain the cause of hyperthyroidism, one of which could be Graves' disease. If TSH receptor antibodies are present and the test is positive, it confirms the diagnosis of Graves' disease. Graves' disease is characterized by the production of thyroid-stimulating immunoglobulin (TSI), which stimulates the thyroid to make too much thyroid hormone, causing symptoms such as heat intolerance, rapid and irregular heartbeat, weight loss, goiter, and exophthalmos.