Endocrine Abstracts

Introduction: Hyperthyroidism is a prevalent condition which affects approximately 2% of the female population and 0.2% of the male population in the UK. 75% of cases are caused by the auto-immune condition, Graves’ disease. Thyrotropin receptor antibodies (TRAb) are raised in 90% of patients with Graves’ disease and are commonly used to investigate the aetiology of thyrotoxicosis.

Background: TRAb can be used to confirm Graves’ disease due to its high sensitivity and specificity, at 98 and 99% respectively. The National Institute for Health and Care Excellence (NICE) clinical advice is to test for TRAb in patients with confirmed hyperthyroidism. Patients who have negative antibodies should then undergo radionuclide thyroid uptake scans.

Aim: To see if patients who attended the endocrinology outpatient clinic at the Royal Liverpool University Hospital had TRAb tested, and to compare this to other methods of investigating the aetiology of hyperthyroidism.

Method: The records of 150 patients who attended the endocrinology outpatient clinic from 2003 to 2017 were analysed. Data was collected to assess if they had TRAb tested. This data was compared to the number of patients who had thyroid peroxidase (TPO) antibody tested, and whether radionuclide thyroid uptake scans were performed.

Results: In the sample of patients, aetiologies of thyrotoxicosis included Graves’ disease (107), toxic multi-nodular goitre (33), solitary toxic nodule (1), thyroiditis (6) and non-specified hyperthyroidism (3). 95.33% of these patients had TRAb tested, 81.33% had TPO tested and 63.33% had a thyroid uptake scan. Of the patients who had Graves’ disease, 57% of patients had a thyroid uptake scan despite having a positive TRAb assay.

Conclusion: From this audit it can be confirmed that most of the patients with hyperthyroidism, who attended the endocrinology outpatient clinic, had their TRAb tested. However, it has been shown that there is an overuse of thyroid uptake scans in patients with Graves’ disease who had a positive TRAb assay. This demonstrates that in clinical practice there is a lack of continuity between interpreting TRAb results and ordering uptake scans. By only performing the scans in TRAb negative patients, clinicians can provide a more clinically efficient and cost-effective service.