Ultrasonographic evidence of a consistent orbital involvement in Graves's disease

Echographic Assessment of Extraocular Muscle Response to Teprotumumab

PURPOSE

To evaluate extraocular muscle response to teprotumumab using orbital echography in thyroid eye disease.

METHODS

This retrospective study included adult thyroid eye disease patients with pre- and post-teprotumumab orbital echography. Data collected included: age, Hertel measurements, clinical activity score, Gorman diplopia scores, ocular motility, and recti muscle diameters measured by echography. The patient's more proptotic eye before treatment initiation was designated as the study orbit. Ocular motility was assessed by totaling the ductions in all 4 cardinal directions. Orbital echography was obtained pre- and post-treatment to assess response of extraocular muscle diameters.

RESULTS

Six patients with a mean age of 67 years were included. There was a mean improvement in proptosis of 4.3 mm in the study eye with 11/12 orbits showing improvement in globe position (p < 0.05). All patients had a decrease in clinical activity score with a mean reduction of 2.5. Four patients had an improvement in Gorman diplopia score. Ocular motility in the study orbits improved by a total mean of 26.9° (p < 0.05). Mean total extraocular muscle diameter was reduced from 27.4 to 23.4 mm (p < 0.001). On average, superior recti were largest pre- and post-treatment, followed by inferior, medial, then lateral recti. However, inferior recti showed the greatest reduction of 23% (p < 0.02).

CONCLUSIONS

Orbital echography demonstrated extraocular muscle reduction in all patients after teprotumumab, correlating with improved clinical activity score, ocular motility, and proptosis. Orbital echography is a safe and cost-effective imaging alternative to monitor therapeutic response to teprotumumab.

Hyperthyroidism is a risk factor for developing adhesive capsulitis of the shoulder: a nationwide longitudinal population-based study

The purpose of this study was to investigate the prevalence and risk of adhesive capsulitis among hyperthyroidism patients. The data were obtained from the Longitudinal Health Insurance Database 2005 (LHID 2005) in Taiwan, using 1 million participants and a prospective population-based 7-year cohort study of survival analysis. The ambulatory-care claim records of patients diagnosed according to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes relating to hyperthyroidism between January 1, 2004 and December 31, 2007, were obtained. The prevalence and the adjusted hazard ratio (HR) of adhesive capsulitis among hyperthyroid patients and the control group were estimated. Of 4472 hyperthyroid patients, 162 (671/100 000 person-years) experienced adhesive capsulitis during the 24 122 person-year follow-up period. The crude HR of stroke was 1.26 (95% confidence interval [CI], 1.06 to 1.49), which was larger than that of the control group. The adjusted HR of developing adhesive capsulitis was 1.22 (95% CI, 1.03 to 1.45) for hyperthyroid patients during the 7-year follow-up period, which achieved statistical significance. The results of our large-scale longitudinal population-based study indicated that hyperthyroidism is an independent risk factor of developing adhesive capsulitis.

Prevalence and risk factors for thyroid eye disease among Korean dysthyroid patients

Purpose

To determine the prevalence of thyroid eye disease among dysthyroid Korean patients and to analyze the relationship between demographic data, lifestyle risk factors, and status of thyroid disease and thyroid eye disease.

Methods

All dysthyroid patients who visited endocrinology clinics in 24 general hospitals in Korea during a chosen one-week period were enrolled in this cross-sectional study. Data were collected during an interviewer-administered questionnaire and chart review. Demographic data, lifestyle risk factors, and status of thyroid disease variables were analyzed as risk factors using multivariable regression models to identify independent associations with thyroid eye disease.

Results

A total of 1,632 dysthyroid patients were included (1,301 females [79.7%] and 331 males [20.3%]). Two hundred eighty-three of these patients (17.3%) had thyroid eye disease. Multiple logistic regression analyses revealed that female gender, young age, Graves' disease, dermopathy, anti-thyroid medication treatment, and radioiodine treatment were independent risk factors for thyroid eye disease.

Conclusions

The lower prevalence of thyroid eye disease in dysthyroid Korean patients and the influence of gender on risk factors in this study are novel findings compared to studies performed involving Europeans. Although the risk factors for thyroid eye disease are understood in part, a more in-depth comparative study of gender and ethnic groups is needed to fully understand the biological significance of the demographic factors.

Update on advanced imaging options for thyroid-associated orbitopathy

Thyroid-associated orbitopathy (TAO) is a diverse spectrum of signs and symptoms that appears to have immunologic and pathologic causative factors as diverse as its clinical presentations. Lymphocytes, hormones, and cytokines affect orbital fibroblasts and other similar cells, which exert their effects on orbital tissues, including the extraocular muscles, orbital fat, and optic nerve. This complicated inflammatory cascade and the myriad of clinical findings that result contributes to the active phase of TAO. The distinction between the active and inactive phases of TAO is an important one, as the proper treatment will depend on the disease phase and degree thereof. Several clinical grading scales and scores have been established to help qualify and quantify the disease severity. Aiding clinical exam and acumen, proper and reproducible imaging of the orbit and ocular adnexa is incredibly important to the management of TAO. Orbital ultrasound, computed tomography, magnetic resonance imaging, and scintigraphy each have unique abilities, including quantifying orbital changes, assessing disease activity, correlating orbital findings with clinical changes, guiding appropriate treatment, and monitoring therapeutic responses. Further, study ease, accessibility, cost, sensitivity, specificity, reproducibility, and risks are all important considerations in picking the right test with which to diagnose and follow TAO. This analysis will provide a review of orbital imaging for TAO, including the mechanism of each imaging technique as well as their rationales, advantages, disadvantages, and utilities.

Treatment modalities for Graves' ophthalmopathy: systematic review and metaanalysis

BACKGROUND

Graves' ophthalmopathy (GO) is a common cause of morbidity in patients with Graves' disease. Optimal treatment of GO remains unclear, and an evidence-based approach may improve patients' outcome.

METHODS

A systematic review and metaanalysis of randomized, controlled trials comparing treatment modalities for GO vs. placebo, no intervention, or other treatments. Primary outcome was the clinical activity score (CAS).

RESULTS

Thirty-three trials evaluating 1367 patients fulfilled inclusion criteria. In patients with moderate to severe GO, iv pulse corticosteroids were significantly better than oral corticosteroids in reducing CAS [standardized mean difference -0.64, 95% confidence interval (CI) -1.11 to -0.17, chi(2) 7.91, I(2) 62%, random effect], with lower rate of adverse events. Somatostatin analogs showed a minor but statistically significant advantage over placebo (mean difference -0.63, 95% CI -0.98 to -0.28). There was no advantage of orbital radiotherapy over sham radiation in CAS, but radiotherapy was superior for response rates of diplopia (odds ratio 4.88, 95% CI 1.93-12.34, two trials). Treatment with combination of orbital radiotherapy and corticosteroids was significantly better than with either treatment alone (standardized mean difference -1.05, 95% CI -1.62 to -0.48).

CONCLUSIONS

Current evidence demonstrates the efficacy of iv corticosteroids in decreasing CAS in patients with moderate to severe GO. Intravenous pulse corticosteroids therapy has a small but statistically significant advantage oral therapy and causes significantly fewer adverse events. Somatostatin analogs have marginal clinical efficacy. The efficacy of orbital radiotherapy as single therapy remains unclear, whereas the combination of radiotherapy with corticosteroids has better efficacy than either radiotherapy or oral corticosteroids alone.

Smoking and thyroid-associated ophthalmopathy: A novel explanation of the biological link

INTRODUCTION

Cigarette smoking is the strongest modifiable risk factor for developing thyroid-associated ophthalmopathy (TAO), and the severity of TAO is related to the current number of cigarettes smoked per day. We aimed to establish the effects of cigarette smoke extract (CSE) on an in vitro model of TAO.

METHODS

Orbital tissue was taken during surgery from 10 patients with TAO and nine control subjects. Orbital fibroblasts were cultured and exposed to CSE, and intercellular adhesion molecule 1 (ICAM1) expression was measured by flow cytometry. Glycosaminoglycan production was measured by hyaluronic acid ELISA. Orbital fibroblasts were grown in adipogenic media with or without CSE and/or IL-1, and the degree of adipogenesis was quantified.

RESULTS

Fibroblasts from patients with TAO and controls showed similar responses. ICAM1 expression was not affected by CSE. Hyaluronic acid production was stimulated by CSE in a dose-dependent manner (correlation coefficient, 0.978; P = 0.022), with 5% CSE causing an increase of 44% (P = 0.001). CSE increased adipogenesis in a dose-related manner, as did IL-1. The effects of CSE and IL-1 on adipogenesis were synergistic, with the degree of adipogenesis in the well containing both 5% CSE and 0.1 ng/ml IL-1 being double the magnitude of the sum of the values obtained from either stimulus alone (P < 0.001). Addition of an anti-IL-1 antibody to the well containing both 5% CSE and 0.1 ng/ml IL-1 reduced the degree of adipogenesis by 82% (P < 0.001).

CONCLUSION

These findings may help explain how cigarette smoking has a detrimental effect in TAO and suggests that IL-1 may be an attractive therapeutic target in TAO.

Occult thyroid eye disease in patients with unexplained ocular misalignment identified by standardized orbital echography

PURPOSE

To describe the clinical presentation, orbital echography (OE) findings, and neuroimaging results of patients with chronic unexplained ocular misalignment, which includes patients with clinically occult thyroid eye disease (TED) that is identifiable through a characteristic OE appearance.

DESIGN

Retrospective observational case series.

METHODS

Seventy-eight patients with chronic ocular misalignment suspected of TED because of a history of systemic thyroid disease, proptosis, dysmotility, positive forced ductions, or eyelid retraction or lag were categorized as TED positive, negative, and indeterminate with the use of standardized OE. Demographic, clinical, OE, computed tomography, and magnetic resonance imaging information was collected. Analyses determined the prevalence of TED and differences between TED positive, negative, and indeterminate groups.

RESULTS

Fifty-five percent of the findings were suspicious for and most consistent with TED (TED positive); 26% of the findings were TED negative, and 19% of the findings were TED indeterminate. Of 30 patients with newly diagnosed TED by OE, 70% had no lid retraction, and 20% had no other findings of TED. The inferior rectus followed by the superior rectus/levator complex, medial rectus, and lateral rectus muscles were the most frequently involved muscles. Neuroimaging that was performed in only 26 of 78 patients (33%) did not appear to yield additional diagnostic information.

CONCLUSION

TED is a potential cause of chronic unexplained ocular misalignment in a substantial proportion of patients. These patients frequently present in an occult fashion without other clinical findings that are typical of TED. In these patients, a diagnosis of TED by OE can reduce further costly evaluation. OE appears to have significant clinical usefulness in the diagnosis of TED in patients with unexplained ocular misalignment.

TSH receptor expression in orbital tissue and its role in the pathogenesis of Graves' ophthalmopathy

The TSH receptor (TSHr) is the autoantigen responsible for the hyperthyroidism of Graves' disease. Recent studies suggest that this receptor may also be an autoimmune target in Graves' ophthalmopathy (GO) and pretibial dermopathy (PTD). Its involvement in the pathogenesis of these conditions would help to explain the close clinical associations between hyperthyroidism, GO and PTD. TSHr has been shown to be present in normal orbital and dermal tissues and evidence supports the conviction that expression may be increased in tissues involved in GO and PTD. In the setting of Graves' disease, the expression of this antigen in connective tissues throughout the body may lead to systemic, subclinical connective tissue inflammation. Given this background, local or environmental factors such as circulating or local cytokines, gravitational dependency, anatomic constraint of the bony orbit, or trauma, may augment clinical disease involvement within the orbit and pretibial skin. Alternately, locally enhanced expression of this protein at the sites of clinical disease may not be directly involved in pathogenesis, but could be secondary to the ongoing process, and nonetheless important in disease progression.

Current perspective on the pathogenesis of Graves' disease and ophthalmopathy

Graves' disease (GD) is a very common autoimmune disorder of the thyroid in which stimulatory antibodies bind to the thyrotropin receptor and activate glandular function, resulting in hyperthyroidism. In addition, some patients with GD develop localized manifestations including ophthalmopathy (GO) and dermopathy. Since the cloning of the receptor cDNA, significant progress has been made in understanding the structure-function relationship of the receptor, which has been discussed in a number of earlier reviews. In this paper, we have focused our discussion on studies related to the molecular mechanisms of the disease pathogenesis and the development of animal models for GD. It has become apparent that multiple factors contribute to the etiology of GD, including host genetic as well as environmental factors. Studies in experimental animals indicate that GD is a slowly progressing disease that involves activation and recruitment of thyrotropin receptor-specific T and B cells. This activation eventually results in the production of stimulatory antibodies that can cause hyperthyroidism. Similarly, significant new insights have been gained in our understanding of GO that occurs in a subset of patients with GD. As in GD, both environmental and genetic factors play important roles in the development of GO. Although a number of putative ocular autoantigens have been identified, their role in the pathogenesis of GO awaits confirmation. Extensive analyses of orbital tissues obtained from patients with GO have provided a clearer understanding of the roles of T and B cells, cytokines and chemokines, and various ocular tissues including ocular muscles and fibroblasts. Equally impressive is the progress made in understanding why connective tissues of the orbit and the skin in GO are singled out for activation and undergo extensive remodeling. Results to date indicate that fibroblasts can act as sentinel cells and initiate lymphocyte recruitment and tissue remodeling. Moreover, these fibroblasts can be readily activated by Ig in the sera of patients with GD, suggesting a central role for them in the pathogenesis. Collectively, recent studies have led to a better understanding of the pathogenesis of GD and GO and have opened up potential new avenues for developing novel treatments for GD and GO.

Rationale of treatment in Graves ophthalmopathy

Graves ophthalmopathy is a chronic and multisystem disorder caused by an autoimmune process, characterized by the presence of antibodies that stimulate a general fibroblastic reaction (thyroid gland and lower extremities), and involves orbital fat tissue and muscles. The clinical findings and therapy for the treatment of the exophthalmos, such as changes in extrinsic eye motility, diplopia, optic nerve involvement, and lid retraction, were analyzed, and the various types of surgical treatment currently available for Graves ophthalmopathy were evaluated. The aim was to choose the best option to treat each case. The surgical techniques were transpalpebral decompression by removal of intraorbital fat, three-wall osseous expansion, and zygomatic osteotomy. Adjunctive procedures were lengthening of the levator muscle of the upper eyelid, lengthening of the retractor of the lower eyelid (if necessary), and surgery of the extrinsic muscles to correct diplopia. All these techniques were useful in treating the disease, which is characterized by chronic evolution and, at times, a "malignant" outcome. A total of 39 orbits were treated using different techniques of decompression and secondary adjunctive procedures. Results were analyzed after a minimum 6-month follow-up. It was evident that surgery greatly reduced the degree of exophthalmos and improved eye motility, diplopia, and visual acuity. Close cooperation among a team of specialists, including an endocrinologist, ophthalmologist, neuroradiologist, surgeon, anesthesiologist, and radiotherapist, is essential to manage and to quantify the postoperative results of this complex disorder. The authors' experience and application of different surgical strategies, as based on clinical data and histopathological classification, are presented.

Effect of 131 iodine therapy on the course of Graves' ophthalmopathy: a quantitative analysis of extraocular muscle volumes using orbital magnetic resonance imaging

There remains uncertainty as to the effect of radioactive iodine (131I) therapy on the associated ophthalmopathy (GO). Twenty newly diagnosed patients with Graves' hyperthyroidism treated with 131I (median dose, 15.5 mCi) were followed with ophthalmologic evaluations (OE) and magnetic resonance imaging (MRI) at baseline, 2, and 6 months, and with OE alone at 3 years. For MRI, the superior, inferior, and medial rectus muscle volumes and total muscle volumes (TMV) were measured. Replacement levothyroxine was initiated as low thyroxine (T4) levels were noted. At baseline, 10 patients (50%) showed evidence of mild GO by OE and/or MRI. There was a significant difference in TMV between the 20 patients with Graves' hyperthyroidism and 10 controls (mean +/- standard error [SE]; 2,652 +/- 118 vs. 2,046 +/- 96 mm3; P = 0.002) and between the 10 patients with and 10 without GO (3,006 +/- 96 vs. 2,298 +/- 61 mm3; P = 0.001). TMV correlated with the Hertel score (r = 0.56, P = 0.01). TMV showed no significant change at 2 or 6 months posttreatment. The inferior rectus volume increased slightly at 2 months posttreatment (P = 0.03) but remained stable at 6 months. Furthermore, no significant changes occurred in Hertel scores or in clinical assessments up to 3 years posttreatment and none showed worsening or new development of GO. In conclusion, our results show no significant risk for radioiodine-induced initiation or progression of mild GO.

Controversies in the clinical evaluation of active thyroid-associated orbitopathy: use of a detailed protocol with comparative photographs for objective assessment

Despite many learned publications over recent decades, the assessment of active thyroid-associated orbitopathy (TAO) remains difficult and controversial. There are no biochemical, immunological or imaging investigations which can identify active disease reliably, and clinical assessment is still of paramount importance. We therefore review the strengths and weaknesses of all methods of clinical assessment. A new atlas for clinical assessment of soft tissue signs has been developed, and its reproducibility assessed. It details a suggested protocol that could help standardize descriptions of TAO and allow more objective assessment of its activity and severity. This is relevant to general endocrinologists, who have a crucial role in the identification of patients who require ophthalmological assessment. Certain aspects are more relevant to ophthalmologists and endocrinologists who have a special clinical and research interest in TAO. Unless a reproducible system of assessment is devised and widely adopted, it will remain difficult to interpret research meaningfully, particularly if results appear to contradict.

High-dose intravenous corticosteroid therapy for Graves' ophthalmopathy

In order to compare oral and high-dose iv corticosteroid therapy for Graves' disease, 25 patients with Graves' ophthalmopathy were treated with two weekly iv injections of 1 g of methylprednisolone diluted in 250-500 ml of physiological solution for 6 weeks, and were compared to a group of 26 patients treated with oral prednisone at a dose of 60-80 mg/day progressively reduced every 2 weeks for a total duration of 4-6 months. The efficacy of treatment was evaluated using the ophthalmopathy index score. Patients were followed at 3, 6, 12 months, and afterwards yearly. All patients showed a significant improvement in signs and symptoms of orbital inflammation and a slight improvement in proptosis and diplopia. Relevant side-effects were reported from patients receiving oral therapy, but no significant side-effects were observed in patients treated with high iv doses; a few cases presented with gastric pain (highly sensitive to aluminium oxide or ranitidine), while most of the patients referred to cutaneous rashes and a metal taste that disappeared some hours after the infusion. Improvements observed after treatment have been stable in both groups. In conclusion, in addition to a lower incidence of side-effects compared to the classic oral therapy, the high-dose iv steroid therapy provides efficient and stable improvement in Graves' ophthalmopathy.

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.

Pathogenesis of ophthalmopathy in autoimmune thyroid disease

What causes GO is still a mystery, but the disease process results from a complex interplay of genetic and environmental factors. Genes such as those for HLA genes may determine a patient's susceptibility to the disease and its severity, but environmental factors, often unknown, may determine its course. Once established, the chronic inflammatory process within the orbital tissues appears to take on a momentum of its own. Given our current state of knowledge, the following working scheme for the pathogenesis of GO can be proposed (Fig. 1): On the background of a permissive immunogenetic milieu, circulating T cells in patients with GD, directed against certain antigens on thyroid follicular cells, recognize antigenic epitopes that are shared by tissues contained in the orbital space. Of the cell types residing in these tissues, preadipocytes and fibroblasts, most likely act as target and effector cells of the orbital immune process, respectively. This includes preadipocyte fibroblasts present in the perimysium of extraocular muscles, which do not appear to be immunologically different from those located in the orbital connective tissue. Orbital preadipocyte fibroblasts may be stimulated by unknown circulating or locally produced factors to differentiate into mature adipocytes that express increased levels of TSHr. How autoreactive T cells escape deletion and control by the immune system and come to be directed against a self-antigen presented by cells residing in the thyroid gland and extrathyroidal locations, is still unknown. Proliferation and expansion of autoreactive T cell clones may be due to mimicry of a host antigen by a microorganism, but this remains speculative. T cell recruitment into the orbital tissues is facilitated by certain chemokines and cytokines, which help to attract T cells by stimulating the expression of certain adhesion molecules (e.g., ICAM-1, VCAM-1, CD44) in vascular endothelium and connective tissue cells. These adhesion receptors are known to also play an important costimulatory role by activating T cells and facilitating antigen recognition, which amplifies the cellular immune process. Analysis of variable region genes of T cell antigen receptors in orbital T cells of patients with active GO has revealed their restricted TcR V gene usage, suggesting that antigen-driven selection and/or expansion of specific T cells may occur early in the evolution of GO. T cells and macrophages populating the orbital space are known to synthesize and release a [figure: see text] number of cytokines (most likely a Th1-type spectrum) into the surrounding tissue. Cytokines, oxygen free radicals and fibrogenic growth factors, released both from infiltrating inflammatory and residential cells, act upon orbital preadipocytes in a paracrine and autocrine manner to stimulate adipogenesis, fibroblast proliferation, glycosaminoglycan synthesis, and the expression of immunomodulatory molecules. Smoking, a well-known aggravating factor in GO, may aggravate tissue hypoxia and exert important immunomodulatory effects. The long held hypothesis of a thyroid cross-reactive antigen within the orbital tissues has recently gained significant support by an animal model of GO, and by in vitro and ex vivo studies. If confirmed in immunological studies, these data may well explain the localized infiltration of the orbital tissues by autoreactive lymphocytes that share intriguing molecular features with intrathyroidal lymphocytes. Local release of particular cytokines, TSHr-directed antibodies, or other factors might further enhance adipogenesis, glycosaminoglycan synthesis and expression of immunomodulatory proteins within the orbit. Other factors, including inflammatory cytokines, might act as counterbalancing inhibitors of these effects. However, if the net effect of these changes is to increase the volume of the fatty connective tissues within the orbit, then proptosis, extraocular muscle dysfunction, and periorbital congestion will ensue. Whether this hypothetical sequence of events will finally explain the involvement of the orbit in GD is unknown. Future studies will be aimed at identifying factors that might modulate adipogenesis in orbital cells and clarifying the link between adipogenesis and TSHr expression in the orbit. Taken together, a number of important details in the complex pathogenesis of GO have been resolved in recent years, but many challenges are still ahead. Elucidation of the primary antigen and how it is recognized by the immune system will be key issues.

Role of the eye muscles in thyroid eye disease: identification of the principal autoantigens

Thyroid-associated ophthalmopathy (TAO) is a progressive orbital disorder associated with Graves' hyperthyroidism and, less often, Hashimoto's thyroiditis in which autoantibodies react with orbital antigens and lead to exophthalmos and eye muscle inflammation. Eye muscle (EM) membrane proteins initially reported as 55 and 64 kd are the best markers of ophthalmopathy. The "64-kd protein" is now shown to be the flavoprotein subunit of mitochondrial succinate dehydrogenase and to have a correct molecular weight of 67 kd. We have cloned a fragment of a novel eye muscle protein, which we call G2s, and sequenced 1.4 kb of the full length cDNA. G2s does not share any significant homologies with other reported proteins. The 5.9 kb G2s mRNA, that corresponds to a protein of approximately 220 kd, is expressed in EM, other skeletal muscle and thyroid, but not in other tissues tested. We have also cloned and sequenced a 63-kd eye muscle protein identified as the calcium binding protein calsequestrin. Antibodies against calsequestrin were found in 40% of patients with active ophthalmopathy, but in 0% of normal subjects. Finally, we have sequenced a 19 amino acid fragment of a 55-kd porcine eye muscle membrane protein that exactly matched porcine and human sarcalumenin, a 160-kd glycoprotein localized in the lumen of the longitudinal sarcoplasmic reticulum of the skeletal muscle fiber where it binds calcium. A 53-kd glycoprotein fragment of the molecule corresponds to the 55-kd protein. In a preliminary study, serum antibodies against purified sarcalumenin were detected in 40% of patients with active TAO of less than 1 year duration, but in no controls tested. We porpose that the primary autoantigen in TAO is G2s, which would also explain the association of ophthalmopathy with thyroid autoimmunity, and that antibodies against the intracellular proteins flavoprotein, calsequestrin, and sarcalumenin are secondary markers of an immune-mediated reaction in eye muscle in patients with thyroid autoimmunity.

Serum antibodies reactive with eye muscle antigens and the TSH receptor in a euthyroid subject who developed ophthalmopathy and Graves' hyperthyroidism

Serum antibodies reactive with eye muscle autoantigens, in particular a 64-kDa protein that is also expressed in the thyroid, and the TSH receptor, are associated with the ophthalmopathy that occurs in about 50% of patients with Graves' hyperthyroidism. We have had the opportunity to study a euthyroid, apparently normal, 35-year-old woman with a family history of thyroid autoimmunity and "colitis" but no clinical or biochemical evidence for thyroid disease or ophthalmopathy, who developed Graves' hyperthyroidism and ophthalmopathy together 18 months later. Serum taken when the patient was first seen was positive for antibodies reactive with (i) 9 different eye muscle proteins ranging in size from 15 to 130 kDa, notably those of 64, 55, and 50 kDa, by immunoblotting with eye muscle membranes, (ii) eye muscle and Müller's muscle cell membrane antigens in antibody-dependent cell-mediated cytotoxicity (ADCC), (iii) an eye muscle cytoplasmic antigen in indirect immunofluorescence, and (iv) the TSH receptor as measured in a radioreceptor binding inhibition assay. When she developed Graves' disease, serum concentration of antibodies to the 55-kDa protein had decreased from +2 to +/-, those reactive with other eye muscle antigens had not changed significantly, and TSH receptor antibodies had increased 3-fold. This case report suggests that antibodies reactive with eye muscle antigens and the TSH receptor are markers of the ophthalmopathy and able to predict its development in predisposed subjects. The significance of these findings needs to be confirmed in a prospective study of first-degree relatives of patients with thyroid-associated ophthalmopathy and patients with Graves' hyperthyroidism without eye signs.

MR T2 relaxation time for the assessment of retrobulbar inflammation in Graves' ophthalmopathy

The results of 39 patients with severe Graves' ophthalmopathy (GO), who were monitored by magnetic resonance imaging (MRI) and tonography before and after combined immunosuppressive treatment with cyclosporine and corticosteroids, are presented. A correlation was found between the decrease in T2 relaxation time of the superior, medial, and inferior rectus muscle (p < 0.01) and the response to the immunosuppressive treatment. Muscle thickness and intraocular pressure showed less improvement (p < 0.05). The infiltrative eye signs improved partially in correlation with the T2 relaxation time. By distinguishing inflammation of the extraorbital muscles from fibrosis, the T2 relaxation time can help to select patients that benefit from immunosuppressive treatment as well as to monitor the therapeutic effect.

A polymorphism in the extracellular domain of the thyrotropin receptor is highly associated with autoimmune thyroid disease in females

We and others have described previously a polymorphism at the first position of codon 52 (C52 --> A52) of the human thyrotropin receptor (hTSHr) gene. To determine its potential significance, we studied female (n = 100) and male (n = 25) patients with autoimmune thyroid disease (Graves' disease, n = 91; Hashimoto's thyroiditis, n = 34) and normal individuals [n = 121, female (n = 69), male (n = 52)]. Screening was performed using AciI restriction enzyme digestions of PCR-amplified genomic DNA. All codon 52 polymorphisms were verified by direct DNA sequencing. Data were analyzed using Chi-square or Fisher exact tests and p-values were corrected for multiple comparisons. Our studies demonstrated that this polymorphism is highly associated with autoimmune thyroid disease in the female population (corrected p = 0.008). We found no such association in the male population. Within females, there was a greater association between Graves' disease and the polymorphism (corrected p = 0.017) than between Hashimoto's thyroiditis and the polymorphism (corrected p = 0.090). The polymorphism was present in a higher proportion of Graves' disease patients with Graves' ophthalmopathy and pretibial dermopathy (40%) or Graves' ophthalmopathy, pretibial dermopathy, and acropachy (60%), than in patients with Graves' disease alone (15%), or Graves' disease and Graves' ophthalmopathy alone (17%). In conclusion, a polymorphism (C52 --> A52) of the hTSHr is associated with autoimmune thyroid disease in females.

Echographic monitoring of response of extraocular muscles to irradiation in Graves' ophthalmopathy

PURPOSE

Confirmation of the efficacy of orbital irradiation in Graves' ophthalmopathy is needed due to the unpredictable natural history of the disease, the variation in individual clinical presentations, the contribution of other simultaneous treatments, and the lack of controlled studies using objective criteria to classify and assess response over time. Orbital echography before and at select intervals following orbital irradiation is proposed as an objective parameter of tissue response to orbital irradiation over time.

METHODS AND MATERIALS

From January, 1983 to September, 1993, 55 patients with progressive Graves' ophthalmopathy underwent 20 Gy retrobulbar irradiation. On retrospective review, standardized orbital echography was performed randomly prior to irradiation in 37 of the 55 patients to assess the acoustic characteristics of the extraocular muscles and to quantitate their individual and summed diameters. Twenty-one patients had at least one follow-up echographic evaluation at random intervals of 0 to 27.5 months following completion of irradiation. Twelve patients received steroids before or during irradiation, which were tapered in proximity to completion of radiation. Follow-up ranged from 2 to 65 months with the majority followed at least 6 months (18 patients).

RESULTS

Of the 21 patients with serial studies, 18 showed an interval decrease in individual and summed muscle size over time and return of symmetry. Interval improvement was documented as early as the 1 month follow-up study, with continued improvement seen during the 3-9-month studies, with stability typically achieved within 12 months. One patient had further changes between the 21 and 27.5 month follow-up studies. Exacerbation of disease was, however, echographically demonstrated in three patients at 6.5, 8.5, and 13 months. Follow-up studies in two of these patients again revealed improvement, one following tapered steroids. The third patient required orbital decompression.

CONCLUSION

Objective parameters of response are needed to document both the immediate and long-term outcome of orbital irradiation on the course of Graves' ophthalmopathy and confirm its efficacy. Serial echography is proposed as a new technique for providing parameters to judge response.

Thyroid-associated ophthalmopathy: pathogenesis and clinical management

The pathogenesis of thyroid-associated ophthalmopathy is autoimmune. The questions to which answers are eagerly awaited are the identification of the autoantigen(s) and the definition of the autoimmune processes (cellular or humoral) responsible. Cellular and humoral immune responses and modulation by cytokines, against orbital tissues have been described. A link between the thyroid and the orbit seems inevitable, possibly in the form of a cross-reactive antigen, and top of the list of candidate antigens is the TSH receptor. Optimal treatment of TAO necessitates careful assessment. Thoughtful planning and timing and choice of intervention with conventional therapies, can lead to satisfactory results in the majority of cases. In addition to treating the severe complications, such as optic neuropathy, corneal exposure and muscle misalignment, corrective surgery to reconstruct the appearance of the patient's eyes should be made available.

A new ultrasonographic method to detect disease activity and predict response to immunosuppressive treatment in Graves ophthalmopathy

PURPOSE

To determine whether the internal reflectivity of the eye muscles on A-mode ultrasonography serves as indicator for disease activity in Graves ophthalmopathy, thereby predicting response to immunosuppressive treatment.

METHODS

Eye muscle reflectivity, expressed as percentage of the initial scleral spike, was measured in the superior, medial, and lateral recti, and normal values were determined in 23 healthy controls. These were compared with values in 16 consecutive patients with untreated, moderately severe Graves ophthalmopathy. The accuracy of the measurement was assessed by calculating the intra- and interobserver coefficient of repeatability. Baseline eye muscle reflectivity in the 16 patients was correlated to the therapeutic outcome 24 weeks after start of immunosuppressive therapy. The response to treatment served as indicator for pretreatment disease activity.

RESULTS

Eye muscle reflectivity could be measured reliably, with an intraobserver coefficient of repeatability of 8.2% in controls and 10.2% in patients. Patients had lower reflectivity than controls (54.6 +/- 17.4% versus 70.7 +/- 6.6%; P < 0.001). Reflectivity in eye muscles with the lowest echogenicity was lower in responders than in nonresponders (25.8 +/- 8.4% versus 40.6 +/- 13.6%; P = 0.02). From the individual data, a cut-off value of 40% was derived, which appeared as an accurate predictor of outcome (positive predictive value 73%; 95% confidence interval 39%-94%).

CONCLUSIONS

Measuring eye muscle reflectivity in Graves ophthalmopathy appears to be a reliable new method to determine disease activity, with a promising accuracy in predicting therapeutic outcome of immunosuppressive treatment.

B-scan ultrasonography in Graves' orbitopathy

Diagnosing and monitoring of Graves' Orbitopathy (GO) can be supported by use of Ultrasonography (USG) and Computerized Tomography (CT); they provide supplementary information. In this retrospective study we describe 107 clinical GO patients evaluated by B-scan USG and 27 clinical GO patients evaluated by CT scan. Analysis of 236 B-scan USG included measurements of medial, inferior and lateral rectus muscles. The presence of muscle enlargement and increased orbital fat were noted by the radiologist on 27 CT scans. Sensitivity of both B-scan USG and CT scan were calculated. We suggest that B-scan USG has a high sensitivity, which is equal or better than CT scan sensitivity in diagnosing GO. Furthermore USG A and B scan combination is an effective, accurate tool in diagnosing GO, and optic neuropathy, but it also provides essential information about the GO disease activity.

Retroocular fibroblasts: important effector cells in Graves' ophthalmopathy

Retroocular and pretibial fibroblasts are likely important effector cells in Graves' ophthalmopathy and pretibial dermopathy. Histologic similarities exist between the tissues involved in these clinically diverse extrathyroidal manifestations of Graves' disease. Both conditions are characterized by an accumulation of glycosaminoglycans (GAGs) and an infiltration of lymphocytes. We have shown that particular cytokines, probably released by the local inflammatory cell infiltrate, are capable of stimulating GAG synthesis by retroocular and pretibial fibroblasts. In order to explain the site-selective involvement of these anatomically distinct areas in Graves' disease, we sought to identify unique characteristics shared by retroocular and pretibial fibroblasts. We have shown that affected retroocular and pretibial fibroblasts demonstrate an enhanced HLA-DR response to interferon-gamma treatment and that retroocular fibroblasts are especially sensitive to the GAG-stimulating effect of this cytokine. In addition, we have shown that only affected retroocular and pretibial fibroblasts express the 72 kDa heat shock protein. Therefore, affected retroocular and pretibial fibroblasts possess unique immunologic features that may render them more susceptible to the autoimmune process in Graves' disease. Chronic stimulation of fibroblasts by cytokines released in the local inflammatory milieu may result in excessive GAG production by these cells. The accumulation of these hydrophilic mucopolysaccharides, with attendant edema, leads to the clinical manifestations of Graves' ophthalmopathy and pretibial dermopathy.

Role of magnetic resonance imaging in thyroid-associated ophthalmopathy: its predictive value for therapeutic outcome of immunosuppressive therapy

To investigate the efficacy of magnetic resonance imaging (MRI) in the assessment of thyroid-associated ophthalmopathy (TAO), 51 patients with TAO were evaluated by ophthalmologic examinations and MRI at 0.5 T. Thickness of extraocular muscles (EM) was measured by T1-weighted image. Signal intensities of EM and orbital connective tissue (OCT) were measured by short inversion time inversion recovery (STIR) image and expressed as a ratio by comparison to the signal intensity of cerebral substantia alba (SI, signal intensity ratio). Significant enlargement of one or more EM was observed in 86% of patients with TAO, and SI of EM (2.15 +/- 0.63, mean +/- SD) was significantly increased compared with control values (n = 16; 1.35 +/- 0.33; t test, p < 0.01). SI of OCT tended to be greater than that in the control group, although the difference was not significant. There was a significant positive correlation between thickness of EM and severity of ophthalmopathy, assessed as an ophthalmopathy index (p < 0.05). SI of neither EM nor OCT correlated with the severity of the eye disease. To investigate whether MRI findings could predict the outcome of methylprednisolone pulse therapy, we studied 23 patients with TAO who received this treatment. SI of EM and OCT in the 12 patients giving favorable responses were significantly greater than those in the 11 patients without good response (t test, p < 0.01). On the other hand, the thickness of eye muscles did not correlate with the outcome of treatment except for that of medial rectus muscle. There was a significant correlation between SI of EM and that of OCT (r = 0.78, p < 0.01), suggesting possible similar pathologic processes in these tissues in TAO.(ABSTRACT TRUNCATED AT 250 WORDS)

Significance of antibodies reactive with a 64 kDa eye muscle membrane antigen in patients with thyroid autoimmunity

SDS-polyacrylamide gel electrophoresis and Western blotting for antibodies reactive with a 64 kDa protein in pig eye muscle membrane was carried out in patients with lid lag and retraction, but no other signs of ophthalmopathy, associated with thyroid disease or nonimmunologic goiter and in patients with Graves' hyperthyroidism without ophthalmopathy who were studied prospectively to determine the relationship of eye muscle antibodies to clinical features of the ophthalmopathy as they appeared in this group of predisposed patients. Seventy-one percent of euthyroid patients with lid lag and retraction but no established ophthalmopathy had detectable serum antibodies to a 64 kDa eye muscle membrane protein. Much smaller proportions had antibodies to proteins of other MW. In normal subjects with previously detectable antibodies to a 64 kDa protein, serum titers, determined by carrying out immunoblotting at serum dilutions of 1:25-1:6400, were low (< or = 1:100) in all cases tested. On the other hand, titers were higher (1:200-1:6400) in 16 of 22 patients with established ophthalmopathy and in 5 of 7 patients with lid lag and retraction tested. Titers tended to be lower in patients with ophthalmopathy of > or = 3 years duration than in those of < or = 1 year duration. Antibody titers were low (1:25) in 6 of 7 patients with Graves' hyperthyroidism without evident eye disease tested. Antibodies to a 64 kDa eye muscle membrane protein were predictive of the development of ophthalmopathy in patients with Graves' hyperthyroidism studied prospectively for periods of 8-42 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Role of connective tissue autoimmunity in Graves' ophthalmopathy

Histologic similarities exist between the tissues involved in the extrathyroidal manifestations of Graves' disease, namely ophthalmopathy and pretibial dermopathy. Both conditions are characterized by an accumulation of glycosaminoglycans (GAGs) and an infiltration of lymphocytes. We have shown that interleukin-1 and transforming growth factor-beta, cytokines released by the local inflammatory cell infiltrate, are capable of stimulating GAG synthesis by retroocular and pretibial fibroblasts. Additionally, affected retroocular and pretibial fibroblasts demonstrate an enhanced induction of HLA-DR in response to interferon-gamma treatment and both cell types express the 72 kDa heat shock protein in vivo and in vitro. Retroocular and pretibial fibroblasts from patients with Graves' ophthalmopathy and pretibial dermopathy thus seem to possess unique immunological features that may render them more susceptible to the autoimmune process in Graves' disease. Chronic stimulation of fibroblasts by cytokines released in the local inflammatory milieu may result in excessive GAG production. The accumulation of these hydrophilic mucopolysaccharides, with its associated edema, leads to the clinical manifestations of Graves' ophthalmopathy and pretibial dermopathy.

The role of increased intraocular pressure on upgaze in the assessment of Graves ophthalmopathy

The significance of the increase in intraocular pressure (IOP) on upgaze in the diagnosis of Graves ophthalmopathy and its normal range are controversial. The authors measured the increase in IOP on upgaze in 69 hyperthyroid patients with Graves disease, diagnosed at 1 month to 15 years previously, to assess their clinical, laboratory, and ophthalmic state. Ninety-seven healthy subjects served as controls. The distribution of increase in IOP on upgaze values in 46 patients with noninfiltrative ophthalmopathy (classes 0 to 1) was the same as in the control group. The 23 patients with infiltrative ophthalmopathy (classes 2 to 4) had increased frequency of higher increases in IOP on upgaze values compared with the other two groups. However, because of considerable overlap, increase in IOP on upgaze was not discriminatory between the groups. Increase in IOP on upgaze correlated positively with the severity of exophthalmos. There was no correlation among age, sex, time since diagnosis, thyroid functional state, and drug therapy. The authors conclude that an increase in IOP on upgaze is a normal finding augmented by Graves infiltrative ophthalmopathy. It has no diagnostic advantage over the simple clinical signs of ophthalmopathy.

The ophthalmopathy of Graves' disease

Fortunately, most patients with thyroid-related eye disease have mild ocular involvement that spontaneously involutes. Less than 5% of patients with hyperthyroidism will develop sufficiently severe ocular abnormalities that will require surgical intervention. Most patients with thyroid eye findings should be symptomatically managed. Some will require use of either topical drops or oral steroids to alleviate their eye problems. In approximately one half of those patients who present acutely with severe thyroid orbital finding, nonsurgical therapies will be sufficient to control their eye disease. In the other half, eventually multiple surgical procedures may be required, and as discussed previously, the timing and sequence of those procedures are crucial to achieve optimal results.

Ophthalmopathy in early thyrotoxicosis--relationship to thyroid receptor antibodies and effects of treatment

A prospective study of 25 newly diagnosed thyrotoxic patients was undertaken to determine the incidence and severity of ophthalmopathy in the early stages of the disease. A quantitative analysis of the ocular muscle changes was made using B scan ultrasonography, and the effects of treatment for the thyroid disease on the course of the eye changes was assessed. Although the majority (75%) of patients showed only mild clinical signs of ophthalmopathy (Werner Class 3 or less), 92% had ultrasonographic evidence of ocular muscle enlargement. Clinical involvement of the extraocular muscles was seen in 12% of the cases. There was an inverse correlation between the serum level of thyroid stimulating hormone receptor antibody (TR Ab) and the size of the extraocular muscles. Recovery of the euthyroid state with treatment was accompanied by a decrease in orbital infiltration in some cases, both clinically (reduced amplitude of intraocular pressure rise on elevation of the globe) and by ultrasonography, but the improvement was not statistically significant.

Orbital decompression of dysthyroid eye disease

Two cases of Graves ophthalmopathy (GO) are presented, both of which required orbital decompression. The indications for orbital decompression and techniques used are discussed and the advantages of inferior orbitotomy presented.

Graves' ophthalmopathy: what is the evidence for extraocular muscle specific autoantibodies

Graves' ophthalmopathy is thought to be an autoimmune disease. Whether this disease is organ specific or one of the manifestations of the closely linked Graves' thyroid disease is still a matter of speculation. Many papers describe autoimmunity to orbital antigens, in particular to extraocular muscles, in patients with Graves' ophthalmopathy. In this paper we have tried to give an overview of the evidence for circulating antibodies against extraocular muscle antigens and to discuss their significance in relation to the immunopathogenesis of the disease.

The use of real-time orbital ultrasound in Graves' ophthalmopathy: a comparison with computed tomography

Evaluation of the severity of orbital involvement and likelihood of the development of optic neuropathy in Graves' disease can be clinically difficult. We describe the use of real-time orbital ultrasound scanning to measure the medial rectus muscle width in 20 patients with Graves' ophthalmopathy and 21 normal individuals. The normal reference interval (to 2 SDs) was 1.75 to 4.07 mm. Significantly (p less than 0.001; Mann Whitney U-test) larger values were observed in the patients compared with controls, and there was good correlation between medial rectus width and a clinical index of disease severity in individual eyes (p less than 0.001; Spearman rank correlation coefficient). Comparison of the medial rectus measurements obtained using orbital computed tomography and ultrasound showed positive correlation at the p less than 0.001 significance level. Computed tomographic medial rectus measurements also correlated with horizontal and vertical muscle indices for that orbit. We suggest that real-time ultrasound of medial rectus width, using widely available equipment, provides an accurate, simple and non-invasive means of evaluating the orbits of patients with Graves' disease. Repeated measurements may be of value in identifying patients at high risk of visual failure, and in following prospectively the orbital response to therapy in patients with Graves' ophthalmopathy.

Temporal relationship between onset of Graves' ophthalmopathy and onset of thyroidal Graves' disease

The temporal relationship between the onset of Graves' ophthalmopathy and the onset of thyroidal Graves' disease was evaluated in 125 consecutive patients with Graves' ophthalmopathy. Thyroidal Graves' disease--past or present--was clinically evident in 99 patients (79%): hyperthyroidism in 3 cases. Thyroid disease preceded the eye disease in 37 patients, it occurred simultaneously with the eye disease in 39 patients, and it developed after the eye disease in 23 patients (in 16 cases within one yr after the onset of eye disease). The age at the onset of thyroid disease (38.7 +/- 12.9 yr) was lower than the age at the onset of ophthalmopathy (41.8 +/- 12.5 yr; p less than 0.001). Among the 26 clinically euthyroid patients (21%) laboratory evidence of thyroidal Graves' disease was found in 14 cases (11%): abnormal TRH test, n = 9; normal TRH test but abnormal T3-suppression test, n = 4; normal TRH and T3-suppression tests but positive thyroid stimulating antibodies, n = 1). We conclude that Graves' ophthalmopathy as a rule develops at a time when thyroid autoimmunity also exists. This strongly suggests a common factor in the pathogenesis of thyroidal and ocular expressions of Graves' disease.

Combined irradiation and low-dose cyclophosphamide in the treatment of Graves' ophthalmopathy

The treatment of a patient with euthyroid Graves' ophthalmopathy is described. A poor response was obtained from large doses of prednisone whereas a combination of orbital irradiation and low dose cyclophosphamide induced a dramatic resolution. As there is no fully satisfactory treatment for this condition, this combined therapy deserves further investigation.