Thyroid Research Thyroid Research Archive Graves’ Ophthalmopathy

Thyrotropin receptors and proinflammatory cytokines are present in orbital tissue in Graves' eye disease

(July 2003)

The background of the study. Graves' eye disease is characterized by inflammation of orbital tissue, but the cause of the inflammation is not known. Orbital tissue contains thyrotropin (TSH) receptors and cytokines (molecules that cause inflammation). In this study, the levels of ribonucleic acid (RNA) coding for TSH receptors and several cytokines were measured in the orbital tissue of patients with Graves' eye disease.

How the study was done. Orbital tissue was obtained at the time of orbital decompression surgery from 6 patients with active Graves' eye disease and 11 patients with inactive Graves' eye disease. RNA was extracted from the orbital tissue and amplified in such a way as to allow quantitation of the RNA coding for the TSH receptor and several cytokines, including interferon, tumor necrosis factor, and interleukins.

The results of the study. TSH-receptor mRNA was detected in the tissue from 5 of the 6 patients with active ophthalmopathy, as compared with 2 of the 11 patients with inactive ophthalmopathy. The content of TSH-receptor mRNA also was higher in the tissue from the patients with active ophthalmopathy. mRNA for several cytokines that promote cellular inflammation was detected in a higher proportion of or in greater amounts in the tissues from patients with active ophthalmopathy. In contrast, there were no differences in the mRNAs for cytokines associated with antibody production and action.

The conclusions of the study. mRNAs for the TSH receptor and inflammatory cytokines are detected more often and in greater amounts in orbital tissue from patients with active Graves' ophthalmopathy than in those with inactive ophthalmopathy.

The original article. Wakelkamp IM, Bakker O, Baldeschi L, Wiersinga WM, Prummel MF. TSH-R expression and cytokine profile in orbital tissue of active vs. inactive Graves' ophthalmopathy patients. Clin Endocrinol 2003;58:280-7.