Endocrine orbitopathy and significance of autoantibodies against 1D protein

BACKGROUND: Endocrine ophthalmopathy is a chronic eye disease, characterized by inflammation in parabulbar and retrobulbar space, occurring usually in Graves' thyrotoxicosis. Although the pathogenesis of the disease has not been clarified until now, it is accepted that this disease is of an autoimmune nature, where the targets of the autoimmune reaction are the antigens shared by thyroid and orbit-tissue. The autoantibodies against recombinant 1D protein are highly specific and sensitive for the diagnosis of endocrine orbitopathy. METHODS AND RESULTS: The aim of our study was to establish, whether the autoantibodies against 1D protein are found predominantly in patients with clinically expressed endocrine orbitopathy. We evaluated in 30 patients with clinically expressed endocrine orbitopathy the thickness of the three retrobulbar eye muscles, damaged by endocrine orbitopathy, determined the parameters of thyroid hormones and anti-TSH receptor autoantibodies. In all patients the detection of circulating autoantibodies against recombinant 1D protein was performed. Autoantibodies against recombinant 1D protein were found in all patients with clinically expressed endocrine orbitopathy. CONCLUSIONS: Immunoreactivity did not depend on the duration or severity of the eye disease, neither on patients' age. We did not find any correlation between the thickness of eye muscles and the titre of anti-TSH receptor autoantibodies, levels of ssTSH and free thyroxine and also any correlation between the thickness of eye muscles and the disease duration.