Adhesion molecule expression in vivo on extraocular muscles (EOM) in thyroid-associated ophthalmopathy (TAO)

The Immunoarchitecture of Human Extraocular Muscles

Purpose

The purpose of this study was to describe the immunoarchitecture of normal extraocular muscles (EOMs) in terms of presence, distribution, and organization of various immune cells.

Methods

We performed unilateral orbital exenterations in six fresh human cadavers from elderly patients, followed by dissection of the medial, lateral, superior and inferior rectus, superior and inferior oblique, and superior palpebral levator muscle in their entirety. We further cross sectioned each EOM in an anterior, central, and posterior third. After immunohistochemical staining for CD3, CD8, CD20, CD138, CD68, and podoplanin, quantitative analysis was performed.

Results

We found all EOMs (rectus, oblique, and levator muscles) to harbor both T- and B-lymphocytes, with a B-lymphocyte dominance and an absence of plasma cells. The highest prevalence of immune cells was seen in the muscle bellies, with, on average, 488 ± 63 CD3+ T-lymphocytes and 44 ± 110 CD20+ B-lymphocytes per mm2, and significant differences from the anterior (T-lymphocytes) and posterior (T- and B-lymphocytes) thirds. T- and B-lymphocytes were primarily organized in hotspots in the vicinity of blood vessels. In addition, a small resident population of macrophages scattered throughout the specimens was detected. No lymphatic vessels were found in any of the EOMs.

Conclusions

These findings can serve as a reference dataset in the assessment of EOM biopsies in the diagnostic process of inflammatory orbital and systemic disorders. Moreover, from a regenerative perspective, our results highlight the importance of taking into account the presence of a resident immune cell population when studying the host immune response on transplanted tissues or engineered constructs.

Integrative transcriptomics and proteomic analysis of extraocular muscles from patients with thyroid-associated ophthalmopathy

Our study aimed to reveal the underlying pathologic mechanisms of thyroid-associated ophthalmopathy (TAO) by integrative transcriptomics and proteomic analysis of extraocular muscles (EOM). The study involved 11 TAO patients (clinical activity score ≤ 2) and 11 control donors. Total RNA was extracted from EOM samples of 5 TAO patients and 5 control individuals for gene microarray analysis to reveal differentially expressed genes. Concurrently, EOM samples from 3 TAO patients and 3 control individuals were lysed for quantitative proteomic analysis. Differentially expressed genes and proteins were identified, followed by functional and pathway enrichment analysis and protein-protein interaction network construction. Concordance between proteins and transcripts was examined, and functional annotations were conducted. Expressions of versican (VCAN) and lipocalin 1 (LCN1) in EOM samples from another 3 TAO patients and 3 control individuals were measured by western blotting. In total, 952 genes and 137 proteins were identified as differentially expressed, as well as 96 differentially expressed proteins without significantly changed mRNA abundance. Proteins mainly related to the composition (such as MYH1, MYH2, and MYH13) and contraction force (MYH3, MYH8, ACTN3, and TNNT1) of the muscle fibers were significantly up-regulated in EOM samples of TAO, as well as those (such as VCAN, MPZ, and PTPRC) associated with cell adhesion. In addition, differentially expressed proteins related to the components and metabolism of extracellular matrix (ECM) (such as COL1A1, COL1A2, COL2A1, VCAN, OGN, and DCN) were identified. Similarly, expressions of genes involved in cell adhesion and ECM metabolism were significantly different between EOM samples of TAO patients and controls. Western blotting verified that VCAN involved in ECM proteoglycans and diseases associated with glycosaminoglycan metabolism was markedly higher in EOM samples of TAO, whereas LCN1 was obviously decreased. In conclusion, this study demonstrated the significantly altered cellular components of EOM, muscle contraction, cell adhesion and ECM metabolism, which might be involved in the pathologic mechanisms and/or consequences of TAO.

Immunohistochemical analysis of human orbital tissue in Graves' orbitopathy

PURPOSE

Immunohistochemistry of orbital tissues offers a correlation between the microscopic changes and macroscopic clinical manifestation of Graves' orbitopathy (GO). Summarizing the participation of different molecules will help us to understand the pathogenesis of GO.

METHODS

The pertinent and current literature on immunohistochemistry of human orbital tissue in GO was reviewed using the NCBI PubMed database.

RESULTS

33 articles comprising over 700 orbital tissue samples were included in this review. The earliest findings included the demonstration of HLA-DR and T cell (to a lesser extent B cell) markers in GO orbital tissues. Subsequent investigators further contributed by characterizing cellular infiltration, confirming the presence of HLA-DR and TSHR, as well as revealing the participation of cytokines, growth factors, adhesion molecules and miscellaneous substances. HLA-DR and TSHR are over-expressed in orbital tissues of GO patients. The inflammatory infiltration mainly comprises CD4 + T cells and macrophages. Cytokine profile suggests the importance of Th1 (especially in early active phase) and Th17 immunity in the pathogenesis of GO. Upregulation of proinflammatory/profibrotic cytokines, adhesion molecules and growth factors finally culminate in activation of orbital fibroblasts and perpetuation of orbital inflammation. The molecular status of selected parameters correlates with the clinical presentation of GO.

CONCLUSION

Further investigation is warranted to define precisely the role of different molecules and ongoing search for new players yet to be discovered is also important. Unfolding the molecular mechanisms behind GO will hopefully provide insights into the development of novel therapeutic strategies and optimize our clinical management of the disease.

High circulating levels of sICAM-1 and sVCAM-1 in the patients with Hashimoto's thyroiditis

OBJECTIVE

To investigate whether soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cell adhesion molecule-1 (sVCAM-1) levels are increased in euthyroid patients with Hashimoto's thyroiditis (HT) and whether they are associated with thyroid autoimmunity and metabolic parameters.

DESIGN

Cross-sectional.

SUBJECTS AND METHODS

In total, 80 euthyroid patients with HT and 80 age- and body mass index (BMI)-matched control participants were included. Serum sICAM-1, sVCAM-1, free triiodothyronine (fT3), free thyroxine (fT4), thyroid-stimulating hormone (TSH), thyroid peroxidase antibody (anti-TPO), thyroglobulin antibody (anti-TG), fasting blood glucose (FBG), insulin, and lipid levels and homeostasis model assessment for insulin resistance (HOMA-IR) were assessed in all participants.

RESULTS

The patients with HT had significantly higher levels of sICAM-1 and sVCAM-1 than controls (both p < 0.001). The difference was sustained after adjustment for TSH and levothyroxine use. Regression analysis demonstrated that sICAM-1 was related to anti-TPO (p < 0.001), and sVCAM-1 was related to both anti-TPO and-TG (p < 0.001 and p = 0.03, respectively); this relationship was sustained after adjustment for age and BMI. Although FBG and HOMA-IR were higher in the HT group, logistic regression analysis revealed that there was no effect of anti-TPO, anti-TG, sICAM-1, sVCAM-1, and C-reactive protein (CRP) on the occurrence of high FBG and high HOMA-IR.

CONCLUSION

sICAM-1 and sVCAM-1 levels were significantly elevated in the patients with euthyroid HT and correlated closely with thyroid autoimmunity. However, soluble adhesion molecules had no relation with glucose metabolism parameters in the HT patients.

Serum levels of adhesion molecules ICAM-1 and VCAM-1 and tissue inhibitor of metalloproteinases, TIMP-1, are elevated in patients with autoimmune thyroid disorders: relevance to vascular inflammation

Serum levels of ICAM-1 (Inter Cellular Adhesion Molecule-1), VCAM-1 (Vascular cell Adhesion Molecule-1-I), TIMP-1 (tissue inhibitor of metalloproteinases 1) and MMP-9 (Metalloproteinase 9) are well established markers of inflammation. The physiopathological link between inflammation, atherosclerosis and autoimmunity is well demonstrated. However, serum levels of these biomarkers in patients with autoimmune-mediated dysthyroidism, including their evolution after improvement of the thyroid disorder have not been assessed. So, we evaluated the circulating levels of these markers in autoimmune and in non-autoimmune-mediated dysthyroid patients, and their evolution after treatment of thyroid disease. We conducted a prospective study to evaluate these markers before and after treatment in hyperthyroid patients (n = 33; 28 patients with autoimmune disease), hypothyroid patients (n = 38; 33 patients with autoimmune disease) and euthyroid subjects (n = 33). At baseline, serum levels of ICAM-1, VCAM-1 and TIMP-1 were significantly elevated in patients with hyperthyroidism as compared to euthyroid and hypothyroid patients (respectively p = 0.0005 and p < 0.0001). In multivariate analysis, the differences remained significant for VCAM-1 and TIMP-1. Median levels of ICAM-1, VCAM-1 and TIMP-1 were significantly higher in patients with autoimmune-mediated dysthyroidism compared to euthyroid patients (respectively p < 0.0001 and p = 0.002). In hyperthyroid patients, ICAM-1, VCAM-1 and TIMP-1 concentrations fell significantly after they had become euthyroid (respectively p = 0.0006; p < 0.0001 and p = 0.0009), although VCAM-1 values remained higher than those observed in the control group (p = 0.005). We found that autoimmune-mediated dysthyroidism were associated with increased peripheral blood concentrations of VCAM-1, ICAM-1 and TIMP-1. Whether these biological abnormalities translate into increase intima remodelling and atherosclerosis remains to be studied.

The effects of tumour necrosis factor-alpha and interleukin1 on an in vitro model of thyroid-associated ophthalmopathy; contrasting effects on adipogenesis

OBJECTIVE

Cytokines are likely to play a key pathogenic role in thyroid-associated ophthalmopathy (TAO). Anti-cytokine therapy has been proposed to be a possible treatment for active TAO. We aimed to establish the effects of selected cytokines on intercellular adhesion molecule 1 (ICAM1) expression, glycosaminoglycan (GAG) production and adipogenesis in orbital fibroblasts (OFs) from patients with TAO.

METHODS

Orbital tissue was taken during surgery from eight patients with TAO and five control subjects. OFs were cultured and ICAM1 expression measured by flow cytometry. GAG production was measured by hyaluronic acid ELISA. OFs were grown in adipogenic media and the degree of adipogenesis quantified.

RESULTS

Responses were similar in OFs from patients with and without TAO. Tumour necrosis factor-alpha (TNFalpha) and interleukin1 (IL1) (0.1 ng/ml) stimulated ICAM1 expression by eight- to ten-fold. Anti-cytokine agents inhibited the cytokine-upregulated ICAM1 expression by 90-99% (P<0.01). TNFalpha and IL1 (0.1 ng/ml) increased hyaluronic acid production by 44 and 95% (P<0.01) respectively. Anti-cytokine agents inhibited these responses by 79-138% (P<0.04).0.013 AU and -1.0; P<0.03) whilst IL1 (0.1 ng/ml) stimulated adipogenesis (+0.05 AU and +5.7; P<0.02) measured by oil-red-O extraction and visual assessment respectively. The anti-IL1 agent inhibited IL1-mediated adipogenesis by 69-106% (P<0.04).

CONCLUSION

TNFalpha and IL1 stimulate ICAM1 expression and GAG production, but have opposite effects on adipogenesis in OFs in vitro. IL1 promotes adipogenesis and its effects can be blocked by anti-IL1 agents in vitro. These agents may be the anti-cytokine treatment of choice for clinical trials in active TAO.

Thyroid associated ophthalmopathy: evidence for CD4(+) gammadelta T cells; de novo differentiation of RFD7(+) macrophages, but not of RFD1(+) dendritic cells; and loss of gammadelta and alphabeta T cell receptor expression

AIM

To characterise periorbital immune cells (stages, kinetics) in active and inactive thyroid associated ophthalmopathy (A-TAO; I-TAO).

METHODS

In orbital tissue cryosections of patients with A-TAO (n = 15), I-TAO (n = 11), and healthy controls (n = 14), adipose and fibrovascular areas were evaluated for MHC II(+) cells, CD45(+) total leukocytes, myeloid cells (CD33(+) monocytes; CD14(+) macrophages; mature RFD7(+) macrophages; RFD1(+) dendritic cells (DCs)), and lymphoid cells (CD4(+) T cells; alphabeta and gammadelta T cells; CD20(+) B cells). Results are expressed as medians and 5% confidence intervals.

RESULTS

In fibrovascular septae, a surge of CD33(+) immigrants clearly correlating with disease activity generated significantly increased (p<0.05) percentages of CD14(+) and RFD7(+) macrophages. Intriguingly, CD4(+) cells were mostly gammadelta T cells, while alphabeta T helper cells were much less frequent. Successful treatment rendering TAO inactive apparently downregulates monocyte influx, macrophage differentiation, and T cell receptor expression. Similar trends were recorded for adipose tissue. Interestingly, RFD1(+) DCs were completely absent from all conditions examined.

CONCLUSION

A-TAO coincides with periorbital monocyte infiltration and de novo differentiation of macrophages, but not DCs. The authors discuss a novel potential role for inflammatory CD4(+) gammadelta T cells in TAO. Successful treatment apparently downregulates orbital monocyte recruitment and effects functional T cell knockout.

TSH-R expression and cytokine profile in orbital tissue of active vs. inactive Graves' ophthalmopathy patients

OBJECTIVE

From in vitro studies using cultures of orbital fibroblasts, it has become clear that cytokines play an important role in the orbital inflammation in Graves' ophthalmopathy (GO). Orbital fibroblasts seem to be the key target cells of the autoimmune attack, and they are able to express the TSH receptor (TSH-R). In vivo data on the presence of cytokines in orbital tissues are sparse, and mostly limited to samples obtained from patients with endstage, inactive GO; the same holds true for the presence of the TSH-R. The aim of the present study was to determine whether the cytokine profile and TSH-R expression differ in the active vs. the inactive stage of GO.

DESIGN AND MEASUREMENTS

Orbital fat/connective tissue was obtained from six patients with active, untreated GO undergoing emergency orbital decompression, and from 11 patients with inactive GO subjected to rehabilitative decompressive surgery. The mRNA levels of various cytokines and the TSH-R were assessed by real-time polymerase chain reaction (PCR) using the LightCycler. Data are expressed as ratios (unknown mRNA/beta-actin mRNA).

RESULTS

Active GO patients had much higher TSH-R expression than inactive patients: 4/0-24 (median value/range) vs. 0/0-9, P = 0.01. TSH-R expression was related to the Clinical Activity Score (r = 0.595, P = 0.015). Patients with active GO compared to those with inactive GO had higher mRNA levels of the proinflammatory cytokines interleukin-1beta (IL-1beta) (445/153-877 vs. 0/0-455, P = 0.001), IL-6 (1583/968-18825 vs. 559/0-7181, P = 0.01), IL-8 (1422/38-7579 vs. 32/0-1081, P = 0.046) and IL-10 (145/58-318 vs. 27/0-189, P = 0.002). In active GO there also existed a trend towards a predominance of T helper 1 (Th1)-derived cytokines as evident from higher IL-2 (37/0-158 vs. 0/0-68, P = 0.043), interferon-gamma (IFN-gamma) (20/0-79 vs. 0/0-16, P = 0.12) and IL-12 (2.3/0-14.8 vs. 0/0-1.6, P = 0.10) mRNAs. IL-1 receptor agonist (IL-1RA), IL-2 receptor (IL-2R), IL-3, IL-4, IL-5, IL-13, IL-18 and tumour necrosis factor-alpha (TNF-alpha) mRNAs were similar in both groups.

CONCLUSIONS

These data show that at the mRNA level, TSH-R expression is largely present only during the active stages of GO. The active phase is characterized by the presence of proinflammatory and Th1-derived cytokines, whereas other cytokines, among them Th2-derived cytokines, do not seem to be linked to a specific stage of GO.

T-cell-mediated immunity in thyroid-associated ophthalmopathy

Thyroid-associated ophthalmopathy (TAO) is considered to be an autoimmune inflammatory disorder of the extraocular muscles and the orbital fat/connective tissue. Recent studies analyzing T cells infiltrating retrobulbar tissues generated important insights into the immunopathogenesis of TAO. The present review focuses on advances in our understanding of mechanisms responsible for the autoimmune inflammation in TAO, especially T cell migration to the inflammatory site, T cell activation by autoantigens and costimulatory signals and their cytokine profile. The elucidation of these processes might lead to the development of novel therapeutic strategies directed against autoreactive T cells.

Smoking and disease severity are independent determinants of serum adhesion molecule levels in Graves' ophthalmopathy

Adhesion molecules play a key role in autoimmune disorders, and serum concentrations of soluble adhesion molecules are increased in Graves' ophthalmopathy (GO). Whether this is due to the strong association with smoking is unknown. It is also not known if the severity or activity of GO determine the serum levels of adhesion molecules. We measured serum concentrations of sICAM-1, sVCAM-1 and sELAM-1 in 62 euthyroid Graves' patients with untreated GO, in 62 healthy controls matched for sex, age and smoking habits, and in 26 euthyroid Graves' patients without GO. GO severity was assessed by the Total Eye Score and the activity by the Clinical Activity Score. Adhesion molecules were measured by highly sensitive ELISAs. GO patients had higher levels than controls (median values in ng/ml with range): sICAM-1 300 [171--575] versus 244 [119--674], P < 0.001; sVCAM-1 457 [317--1060] versus 410 [238--562], P < 0.001; and sELAM-1 61 [19--174] versus 53 [23--118], P = 0.021. Euthyroid Graves' disease patients without GO had levels similar to controls: sICAM-1 273 138--453), sVCAM-1 386 [260--1041] and sELAM-1 46 [22--118]. Smoking had an independent effect and was associated with higher levels of sICAM-1 and lower levels of sVCAM-1 in both GO patients and controls; sELAM-1 levels were comparable. In the 62 GO patients, sICAM-1 correlated significantly with severity of eye disease (r = 0.40, P = 0.002). No correlation was found with the duration of GO, the Clinical Activity Score or TBII levels. Multivariate analysis of all 150 subjects showed that the presence of GO and smoking are independent determinants of sICAM-1 and sVCAM-1 concentrations. In GO patients, the Total Eye Score was a stronger determinant than smoking. It is concluded that (i) smoking is associated with increased sICAM-1 and decreased sVCAM-1 levels; (ii) independent from smoking, euthyroid GO patients have higher levels of sICAM-1, sVCAM-1 and sELAM-1 than patients with euthyroid Graves' disease or healthy controls; (iii) the major determinant of sICAM-1 in GO patients is the severity of their eye disease.

Serum levels of tumor necrosis factor-alpha, soluble intercellular adhesion molecule-1, soluble vascular cell adhesion molecule-1, and soluble interleukin-1 receptor antagonist in patients with thyroid eye disease undergoing treatment with somatostatin analogues

The aim of this prospective, randomized study was to investigate the serum levels of tumor necrosis factor-alpha (TNF-alpha), soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), and soluble interleukin-1 receptor antagonist (sIL-1RA) in patients with thyroid eye disease (TED) before and 1 and 3 months after treatment with somatostatin analogues (SM-a). Thirty patients, all with signs and symptoms of TED, were studied. Twenty-two patients (13 females) had active eye disease with a clinical activity score (CAS) > or = 4 (patients with active disease [PA]) and 8 patients (5 females) had inactive TED with CAS < or = 3 (patients with inactive disease [PI]). All PA patients had a positive orbital octreoscan, whereas PI patients had a negative one. Fifteen patients from the PA group were selected randomly and received SM-a (PA-S subgroup), while the remaining 7 patients were used as control subgroup (PA-C), received neither therapy, nor placebo. From the 15 patients who received SM-a (PA-S), 6 received octreotide (OCT) and 9 lanreotide (LRT). TED was reevaluated using the CAS 1 and 3 months after the initiation of SM-a treatment. Ten healthy individuals (6 females) were used as controls (group C). We found an increase in the basal levels of TNF-alpha (14.2 +/- 7.1 pg/mL), sICAM-1 (809.1 +/- 167.0 ng/mL), and sIL-1RA (542.1 +/- 259.0 pg/mL) in PA patients as a total group compared with the PI (1.6 +/- 1.9, 676.8 +/- 73.4, 267.6 +/- 152.8, respectively) group and C (1.9 +/- 1.4, 598.0 +/- 126.2, 258.6 +/- 155.1, respectively). The basal levels of TNF-alpha (13.3 +/- 8.3 pg/mL) and sIL-1RA (533.7 +/- 308.9 pg/mL) in PA-S as well as in PA-C (16.0 +/- 2.9, 560.2 +/- 107.3, respectively) subgroups were also increased compared with PI patients and C (1.9 +/- 1.4 and 258.6 +/- 155.1, respectively). The same was true for sICAM-1 when baseline levels compared with C (817.1 +/- 187.3 and 791.9 +/- 123.5, respectively vs. 598.0 +/- 126.2 ng/mL). After SM-a, serum levels of sICAM-1 and sVCAM-1 were decreased significantly 1 (781.2 +/- 205.9, 1,193.5 +/- 511.8 ng/mL) and 3 months (786.8 +/- 199.6, 1,122.1 +/- 225.3 ng/mL) after the initiation of treatment. In conclusion, serum levels of TNF-a, sICAM-1, and sIL-1RA were elevated in patients with active TED compared to controls. Furthermore, sICAM-1 and sVICAM-1 levels declined during the treatment with SM-a in patients with active TED.

Activation of a tissue-specific stress response in the aqueous outflow pathway of the eye defines the glaucoma disease phenotype

The glaucomas are a group of optic neuropathies comprising the leading cause of irreversible blindness worldwide. Elevated intraocular pressure due to a reduction in normal aqueous outflow is a major causal risk factor. We found that endothelial leukocyte adhesion molecule-1 (ELAM-1), the earliest marker for the atherosclerotic plaque in the vasculature, was consistently present on trabecular meshwork (TM) cells in the outflow pathways of eyes with glaucomas of diverse etiology. We determined expression of ELAM-1 to be controlled by activation of an interleukin-1 (IL-1) autocrine feedback loop through transcription factor NF-kappaB, and activity of this signaling pathway was shown to protect TM cells against oxidative stress. These findings characterize a protective stress response specific to the eye's aqueous outflow pathways and provide the first known diagnostic indicator of glaucomatous TM cells. They further indicate that common mechanisms contribute to the pathophysiology of the glaucomas and vascular diseases.

Thyroid-associated ophthalmopathy: clinical features, pathogenesis, and management

Thyroid-associated ophthalmopathy (TAO) is a progressive eye disorder characterized by immune-mediated inflammation of the extraocular muscles and orbital connective tissue. TAO is linked, in a unique way, with thyroid autoimmunity, in particular Graves' hyperthyroidism. Our working hypothesis for the pathogenesis of TAO is that recognition of a thyrotropin receptor (TSHR)-like protein in the orbital preadipocytes by antibodies may be the initial event leading to homing of lymphocytes into the orbital tissues. In the course of thyroid inflammation, antibodies and T cells reactive against G2s expressed in thyroid membranes cross-react with the protein in the eye muscle fiber, leading to eye muscle damage and dysfunction. Those patients with anti-G2s antibodies develop ocular myopathy. Antibodies against flavoprotein, the 64-kDa protein, which are produced in the context of eye muscle fiber damage and mitochondrial rupture, are sensitive markers of immune-mediated fiber necrosis in patients with ophthalmopathy but do not directly damage the eye muscle. Antibodies against type XIII collagen, which is localized in the plasma membranes of orbital fibroblast, may be a new marker for the congestive ophthalmopathy subtype of TAO. The measurement of antibodies against key eye muscle and orbital connective tissue autoantigens may have a role in the management of active ophthalmopathy and its prediction in patients with Graves' hyperthyroidism.

T cells and fibroblasts in affected extraocular muscles in early and late thyroid associated ophthalmopathy

AIM

To determine whether there are differences in the lymphocytic cell infiltrate present in affected extraocular muscles (EOM) during early and late stages of thyroid associated ophthalmopathy (TAO).

METHODS

17 biopsies of affected EOMs were collected from two groups of TAO patients (n=14): the first of five patients with early, active TAO, and the second of nine patients with late, inactive TAO. The control group was of EOM biopsies taken from 14 non-TAO patients undergoing squint surgery. Immunohistochemical analysis was undertaken using the relevant monoclonal antibodies and an avidin-biotin system and the three groups compared.

RESULTS

Both CD4+ and CD8+ T cells were found in the cellular infiltrate in early, active TAO specimens which were much less evident either in late, inactive stage disease or in control tissue. There was also a significant increase in both CD45RO+ and CD45RB+ cells and macrophages in early TAO compared with the others. Increased expression of HLA-DR antigen by interstitial cells including fibroblasts was detected in both early and late disease but the EOM fibres remained morphologically intact and did not express MHC class II antigens at any time.

CONCLUSION

These results demonstrate that T cells are only significantly present in early disease but increased HLA-DR antigen expression on fibroblasts is observed at all stages. This suggests that T cells are much more involved in the early than the later stages of the disease process and that early activation of fibroblasts occurs. Early intervention with immunosuppressive therapy to downregulate cytokine production by T cells may significantly influence the sequelae caused by EOM fibrosis.

Management of Graves' ophthalmopathy: reality and perspectives

Graves' ophthalmopathy is an debilitating disease impairing the quality of life of affected individuals. Despite recent progress in the understanding of its pathogenesis, treatment is often not satisfactory. In mild cases, local therapeutic measures (artificial tears and ointments, sunglasses, nocturnal taping of the eyes, prisms) can control symptoms and signs. In severe forms of the disease (3-5%), aggressive measures are required. If the disease is active, high-dose glucocorticoids and/or orbital radiotherapy, or orbital decompression represent the mainstay of treatment. If the disease is severe but inactive, orbital decompression is preferred. Novel treatments such as somatostatin analogs or intravenous immunoglobulins are under evaluation. Rehabilitative (extraocular muscle or eyelid) surgery is often needed after treatment and inactivation of eye disease. Correction of both hyper- and hypothyroidism is crucial for the ophthalmopathy. Antithyroid drugs and thyroidectomy do not influence the course of the ophthalmopathy, whereas radioiodine treatment may cause the progression of preexisting ophthalmopathy, especially in smokers. The exacerbation, however, is prevented by glucocorticoids. In addition, thyroid ablation may prove beneficial for the ophthalmopathy in view of the pathogenetic model relating eye disease to autoimmune reactions directed against antigens shared by the thyroid and the orbit.

[Endocrine orbitopathy 1998]

BACKGROUND

Ophthalmopathy is the most common extrathyroidal manifestation of Graves' disease, also called thyroid-associated ophthalmopathy.

CLINICS

This autoimmune disorder is characterized by a lymphocyte infiltration of the retrobulbar space. Activated T cells react with the target organ and secrete cytokines, leading to accumulation of glycosaminoglycans, interstitial edema of the peri- and retrobulbar tissue and enlargement of the extraocular muscles. During the inflammatory stage, the increased orbital pressure results in the clinical manifestation of the eye disease.

DIAGNOSIS AND TREATMENT

Thus, therapeutic immunosuppression is often used initially, and by suppressing inflammatory changes, it can result in subjective and objective improvement of the thyroid eye disease. In recent years, new pathogenetic aspects and clinical randomized trials led to modified therapy concepts.

CONCLUSION

Interdisciplinary management is recommended for rapid diagnosis and effective therapy of patients with thyroid-associated ophthalmopathy.