The thyroid gland produces hormones thyroxine (T4) and triiodothyronine (T3), which are

vital in regulating the metabolism. Production of these hormones is stimulated by the

thyroid stimulating hormone (TSH).

Anti-TSHR is an antibody against TSH receptor. Two types of Anti-TSHR are known:

• Thyroid stimulating immunoglobulin (TSI), which causes hyperthyroidism by

binding to receptors and mimicking the effects of TSH.

• Thyrotropin-binding inhibitory immunoglobulin (TBII), which causes

hypothyroidism by blocking TSH from binding to receptors.

This test is used for the quantitative determination of TSI in human serum.

Why the Anti-TSHR test is performed?

The test is used to detect Anti-TSHR (thyroid stimulating immunoglobulin) in the serum.

The test is performed when a person has signs or symptoms of Graves disease, toxic

multinodular goiter and to monitor the effectiveness of anti-thyroid therapy.

The test is also done during the third trimester of pregnancy to predict neonatal Graves

disease, because some women may continue producing Anti-TSHR even after clinical cure.

Anti-TSHR are IgG antibodies, so they can cross the placental barrier and cause neonatal

thyrotoxicosis.

How the Test is Performed and How to Prepare for the Test?

A blood sample is drawn from a vein. No special preparation is needed for the test. Useful Information: If a patient is receiving therapy with high biotin doses, blood for the test should be drawn at least 8 hours after the last biotin administration. No specimen should be drawn from patients receiving heparin treatment.

What Do the Abnormal Results Mean?

Higher-than-normal levels may indicate: Graves disease, Hashitoxicosis,Neonatal thyrotoxicosis.

Anti-TSHR is usually present in Graves disease. Elevated Anti-TSHR levels after a course of

antithyroid drug treatment is predictive of Graves disease relapse. However, a normal AntiTSHR test results are not predictive of prolonged remission.

Alternative Names

Anti-TSHR (Thyrotropin Receptor Antibody) is also known as Anti-Thyrotropin, TRAb, Antibodies to TSH receptor, TSH Receptor (Thyroid-Stimulating Hormone Receptor) Antibody, Long-Acting Thyroid Stimulator (LATS), TBII (TSH-Binding Inhibiting Immunoglobulin or Thyrotropin-Binding Inhibitory Immunoglobulin), TSH Receptor Blocking Antibody, TSI (Thyroid stimulating immunoglobulin).