A Case of Euthyroid Graves’ Ophthalmopathy in a Patient Sero-Negative for TSH Receptor Autoantibody

Abstract

We report of a case of Graves' ophthalmopathy presented solely with symptoms of the eyes with normal thyroid function tests and negative immunoreactive TSH receptor autoantibody. 40-year-old male was referred to our hospital due to 2-month history of ocular focusing deficit without any signs or symptoms of hyper- or hypothyroidism. Serum thyroid function tests and 99mTc uptake were both within the normal range. Anti-thyroid autoantibodies were all negative except for the cell-based assay for serum TSH receptor stimulating activity. Since orbital CT scan and MRI gave typical results compatible with Graves' ophthalmopathy, we treated the patients with corticosteroid pulse therapy and orbital radiation therapy, leading to a partial improvement of the symptoms. This case gives insights into the potential pathophysiologic mechanism underlying Graves' ophthalmopathy and casts light upon the difficulties of establishing the diagnosis in a euthyroid case with minimal positive results for anti-thyroid autoantibodies.

A systematic review of euthyroid Graves' disease (Review)

“…The abnormalities upon thyroid examination identified among euthyroid patients are the presence of thyroid enlargement (24-40%), low TSH (14-23%), no or low response of TSH to thyrotropin releasing hormone (TRH) stimulation (40-63%), high thyroid uptake of iodine (20%), negative TSH suppression test (30-73%), positive TgAb (11-67%), positive TBII (31-36%) and positive TSAb (43-87%) ( 29 ). Several cases with negative autoantibodies in patients with specific signs of ophthalmopathy have been reported ( 26 , 32 , 33 ). Moreover, Watanabe et al identified the presence of TSAb in 93% of cases by evaluation with a sensitive bioassay, which indicated its usefulness in the diagnosis of EGD with negative-autoantibodies.…”