Endocrine Abstracts

Graves’ disease (GD) and thyroid-associated ophthalmopathy (TAO) are often observed together. In purpose to elucidate the pathogenetic relationships between these two autoimmune disorders we investigated profile of different autoantibodies in patients with GD without TAO (n=38, group 1), GD with TAO (n=40, group 2), and in healthy people (n=124, control group). Autoantibodies to thyroid gland, eye muscle cell membranes (Ab-EMCM) and skin fibroblasts were detected in sera.

The frequency of detected antibodies to TSH-receptor was: group 1–89.1%, group 2–94.4%, and were not found in control group. The presence of antibodies to thyroidperoxidase was: group 1–77%, group 2–52.5%, control group 4.2%. The frequencies of antibodies to thyroglobulin were 48.2%, 35.7% and 6.4% respectively. AB-EMCM were found in 18% of patients from group 1, 81.1% – from group 2 and 8.5% – from control group. The frequencies of antibodies to fibroblasts were 45.7%, 36.1% and 7.2% respectively. The frequency of detected antibodies to TSH receptor, thyroidperoxidase, thyroglobulin and fibroblasts was significantly higher in groups 1 and 2 compared to control group (P<0.005), and there was no difference between groups without or with TAO. However, concentration of the antibodies to TSH receptor was significantly higher in group 1 compared to group 2 (P<0.01). In contrast, the frequency of AB-EMCM was significantly higher in group 2 than in group 1 and controls (P<0.005). There was a direct correlation between concentration of AB-EMCM and the severity of TAO clinical symptoms (r=0.8, P<0.01). In conclusion, antibodies to fibroblasts are probably not specific for TAO and their appearance reflects polyclonal activation of antibodygenesis in patients with Graves’ disease. According to our data, we suggest that antibodies to eye muscle cell membranes may play an important part in the pathogenesis of thyroid-associated ophthalmopathy.