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.
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