Endocrine Abstracts

Background: TSH-receptor stimulating antibodies are implicated in the pathophysiology of Graves’ disease (GD). The detection of TSH-receptor antibodies (TSHR-Abs) is routinely performed by assays measuring thyrotropin-binding inhibitor immunoglobulin and new generation assays are reported to have high sensitivity and specificity in GD. The differentiation of hyperthyroidism (GD or toxic multinodular goiter (TMG) or toxic adenoma (TA)) is important for planning the therapy and an approach combining cost–effectiveness and patient convenience are essential in common practice.

Objectives: To assess the benefits (diagnostic and financial) of checking the TSHR-Abs (TSHR Autoantibody Coated-Tube, RIA, Kronus, ID, USA) alone in a series of patients presenting with thyrotoxicosis.

Patients and methods: Sixty-seven consecutive patients (58 females, median age 38 years (range 23–89)) who presented with newly diagnosed thyrotoxicosis were studied. Of these, 54 had GD, 6 TMG or TN and 7 subacute thyroiditis (ST). All diagnoses were confirmed with a thyroid uptake scan. Anti-TPO and TSHR-Abs were measured at the time of presentation.

Results: TSHR-Abs were positive in 95.5% (51/53) of subjects with GD and in 0% (0/13) of all other diagnoses. Anti-TPO Abs were positive in 62.7% (33/54) of patients with GD, 50% (3/6) of those with TMG or TA and 57% of patients with ST (4/7). Cost estimation for these tests in our Trust showed that TSHR-Abs alone without uptake scan or Anti-TPO Abs would save £160 per patient providing total savings of £8150 for this series of GD with positive TSHR-Abs.

Conclusion: Our data confirms the significant diagnostic value of the TSHR-Abs in GD; in such cases, the use of this test alone improves the financial burden considerably and avoids the inconvenience of thyroid uptake scans.