Endocrine Abstracts

TSH receptor antibody (TRAb) assays are highly sensitive and specific for the diagnosis of Graves’ disease. TRAb can minimise need for additional radiological modalities such as ultrasound and isotope scan in excluding other causes of hyperthyroidism. The relapse rates of hyperthyroidism following a course of anti- thyroid drugs (ATDs) remains disappointingly high at between 50-70%. TRAb levels at diagnosis and at the completion of a course of ATDs can be useful in predicting potential relapse rates of over 80% where perhaps the patient is better served by choosing a definitive treatment option such as radioiodine (RAI) or surgery at an earlier stage. For patients who choose RAI as the definitive treatment options a high TRAb level is a predictor of potential Graves’ opthalmopathy and can influence the choice of using steroid prophylaxis. TRAb measurement is useful in pregnancy planning in suitable patients, for consideration of definitive options to minimise the use of ATD (and risk of congenital defects). High TRAb concentrations (>3 times cut off) during pregnancy can prompt additional monitoring of the fetus for thyroid dysfunction. TRAb levels are useful in determining duration of therapy in Paediatric Graves’ disease with the recommendation to stop ATD therapy only when TRAb levels have been low for several months. TRAb levels can help guide duration of ATD therapy in patients with immune reconstitution Graves’ disease.

Key References: Kahaly G, J, Bartalena L, Hegedüs L, Leenhardt L, Poppe K, Pearce S, H: 2018 European Thyroid Association Guideline for the Management of Graves’ Hyperthyroidism. Eur Thyroid J 2018;7:167-186. doi: 10.1159/000490384 Hesarghatta Shyamasunder, A. and Abraham, P. (2017), Measuring TSH receptor antibody to influence treatment choices in Graves’ disease. Clin Endocrinol, 86: 652-657. https://doi.org/10.1111/cen.13327