Hello – TSI and TRAb are the two antibody tests that are specific to Graves’ disease. The TSI test is specific to the antibodies that cause *stimulation* of the thyroid in Graves’ disease, leading to hyperthyroidism. The TRAb test picks up both stimulating and blocking antibodies in Graves’ disease. (Blocking antibodies *can* sometimes cause hypOthyroidism in Graves’ patients).
TPOabs are tricker, as that is a “marker” for autoimmune thyroid disease. They are very common in Hashimoto’s Thyroiditis, but a certain percentage of Graves’ patients (even those who do not have HT) test positive for them.
Your doc will likely help you make your treatment decision based on your actual levels. If your TSH is too high, your Free T4 and T3 are too low, and you are having symptoms of hypO – your doc will likely recommend replacement hormone (Synthroid, Tirosint, generic levothyroxine, etc.).