Introduction: Graves hyperthyroidism is an autoimmune disease sustained by auto antibodies binding to and activating the TSH receptor located on the thyroid follicular cell. The diagnosis of Graves hyperthyroidism is based upon clinical symptoms, signs and laboratory tests confirming the presence of thyrotoxicosis, positive thyroid peroxidase (TPO) and less commonly thyroglobulin (Tg) antibodies, and finally, positive serum TSH receptor antibodies (TRab). Recently study reported the positivity for TRab in 95.7% untreated Graves patients.
The aim of our study is to determine the serum TSH receptor antibodies measured by RIA (CIS-Bio) in patients with Graves in our endocrine clinic in Tirana.
Material and methods: During the years 20092010 in our clinic 265 patients were consulted for thyroid disorder and 77.3% (205) were diagnosed with Graves diseases (154 female, 51 males with a ratio 3.01:1. Mean age was 44 years old ±16.2 S.D.); 6% with multinodular toxic goiter; 4.3% with thyroiditis and 12.4% were euthyroid. All the patients were examineted for the presence of anti-TSH receptor by RIA (Cisbio) and the cut off for positivity was >1.0 U/ml. As control we took a group of normal subject and with Hashimoto hypothyroidism.
Results: With a cut-off point of TRAb ≥1 U/l the TRAb antibodies were positive in 90.7% of patients with Graves disease before treatment with an average level 8.89 U/l±13.71 S.D. with a range 1.1105. In those without Graves disease, TRAb were positive in 1.6% one patient with autoimmune thyroiditis and undetectable in euthyroid and multinodular toxic goiter and normal controls.
Conclusion: In this study, we conclude that TRAb assay is of great interest in confirming the diagnosis. Using these assays in clinical routine is helpful in the differential diagnosis of hyperthyroidism, since the presence of autoantibodies confirms GD, while their absence indicates a non autoimmune origin of hyperthyroidism.
30 Apr - 04 May 2011
European Society of Endocrinology