Thyroid-Stimulating Immunoglobulin (TSI)

Graves's disease is a classic form of hyperthyroid disease, affecting approximately 0.4% of the population of the United States. It is caused by IgG immunoglobulins, collectively known as thyroid stimulating immunoglobulins (TSI). Patients who are candidates for antithyroid drug therapy may not respond to this treatment when TSI levels are markedly elevated.

Significant deviations from the normal range may require further evaluation by your physician.

Thyroid-stimulating immunoglobulins (TSI) can be detected in the majority of patients (77.8%) with Graves' disease. These antibodies have also been associated with a small portion (15.9%) of patients with toxic multinodular goiter. It has also been reported that TSI measurement can be used to predict relapse or remission when methimazole or radioiodine is used to treat Graves' disease. These assays have also been advocated for use in patients with subclinical Graves' hyperthyroidism or patients with unilateral ophthalmopathy.