Extrathyroidal Manifestation Of Graves Disease Research Articles

A Review of Novel Medical Treatments for Thyroid Eye Disease

Thyroid eye disease (TED) is the most common extrathyroidal manifestation of Graves disease. There has been no effective medication to prevent proptosis in thyroid eye disease until 2020 when the anti–insulin-like growth factor 1 receptor (anti–IGF-1R) antibody, Teprotumumab, was approved by the US Food and Drug Administration, sparking increased interest in immune-based drug development. This study aims to review the newly developed drug therapy as well as conventional treatment for TED. Treatment of TED has traditionally been high-dose steroids and orbital radiotherapy, but recently there has been a paradigm shift in the treatment of TED in the United States with the introduction of the therapeutic agent teprotumumab, which dramatically reduces proptosis. However, concerns remain about the development of hearing impairment as a potentially fatal complication and long-term safety. Recently, several clinical trials are underway to assess the efficacy and safety of novel drugs targeting mammalian target of rapamycin complex 1, interleukin-6, fragment crystallizable receptor, and IGF-1R in treating TED. With the explosive increase in interest from academia and pharmaceutical companies in TED, there is anticipation for the development of drugs that are equivalent or superior to teprotumumab while being safer.

Thymic hyperplasia is accurate to detect new-onset Graves' hyperthyroidism and resolves after restoring euthyroidism.

Abnormal liver blood tests (ALBTs), neutropenia (NEU) and thymic hyperplasia (TH) are new features of Graves' disease (GD). Our objectives were: (a) to calculate the accuracy of TH in discriminating between Graves' and non-Graves' thyrotoxicosis, compared to ALBTs, NEU and Graves' orbitopathy (GO); (b) to explore the outcome of GD-associatedTH and non-GD-associated TH. We prospectively analyzed consecutive adult patients with newly diagnosed thyrotoxicosis from January 2018 to June 2023. TH was detected via neck ultrasound (nUS) then confirmed and followed by magnetic resonance imaging (MRI). For GD vs non-GD clinical sensitivity (SE) and specificity (SPEC), accuracy, positive predictive value (PPV) and negative predictive value (NPV) of GO, TH, ALBTs and NEU were calculated. 264 thyrotoxic patients were included. TH was found in 16.4% (20/122) of GD vs 1.4% (2/142) in non-GD (p < 0.001). SE, SPEC, accuracy, PPV and NPV of the four extrathyroidal manifestations of GD were as follows, respectively: GO 26%, 100%, 66%, 100%, 61%; ALBTs 41%, 89%, 69%, 76%, 66%; NEU 5%, 100%, 56%, 100%, 55%; TH 16%, 98%, 61%, 91%, 98%. In 18 of them, TH regressed within 12months after achieving euthyroidism under anti-thyroid drug therapy, while in the remaining 2, TH regressed 6 months after thyroid surgery. In the two non-GD patients with TH, thymus disappeared along with euthyroidism. TH in the hyperthyroidism scenario provides a high PPV for GD. A conservative approach for the diagnostic work-up and initial management of thyrotoxicosis-associated TH should be adopted.

OR26-03 Treatment With Linsitinib, An IGF-1 Receptor Inhibitor, Prevents Disease Development And Progression In An Experimental Model Of Thyroid Eye Disease

Abstract Disclosure: A. Gulbins: Grant Recipient; Self; Sling therapeutics, Inc. M. Horstmann: Grant Recipient; Self; Sling therapeutics, Inc. A. Daser: None. U. Flögel: None. M. Oeverhaus: Grant Recipient; Self; Sling therapeutics, Inc. B.E. Nikolaos: None. J.P. Banga: None. G. Krause: None. G.D. Hammer: Research Investigator; Self; Sling therapeutics, Inc. A.G. Spencer: Research Investigator; Self; Sling therapeutics, Inc. R. Zeidan: Research Investigator; Self; Sling therapeutics, Inc. A. Eckstein: Grant Recipient; Self; Sling therapeutics, Inc. S. Philipp: Grant Recipient; Self; Sling therapeutics, Inc. G. Görtz: Grant Recipient; Self; Sling therapeutics, Inc. Study objective: We investigated the effect of linsitinib, a small molecule inhibitor of the Insulin like growth factor 1 receptor (IGF-1R), on Graves’ disease and thyroid eye disease. Graves‘ disease (GD), also known as “Basedow's disease“, is the most common cause for hyperthyroidism, typically presenting in patients between 40-60 years. GD is an autoimmune condition of the thyroid which is caused by autoantibodies against the thyroid stimulating hormone receptor (TSHR). Thyroid eye disease (TED) is the most common extra thyroidal manifestation of GD and occurs in about 50% of the clinical cases. Methods: To induce Graves’ Disease in mice we immunized mice 3-times with a plasmid encoding for the A-subunit of the TSHR. During each active (early) and chronic (late) states of the autoimmune disease, linsitinib was administered orally for four weeks. Endocrine orbitopathy and inflammation were determined by histology and MRI. Results: As seen in the histology, linsitinib prevented autoimmune hyperthyroidism, morphological changes, formation of brown adipose tissue in the orbita and orbital T-cell and macrophage infiltration into the orbit in the active state as well as the chronic phase. To evaluate the effect of linsitinib during the course of therapy, living mice were examined via MRI. A distinctive migration of immune cells in the orbit with consecutive inflammation can be seen in the TSHR-immunized group, which is completely blocked by treatment with linsitinib. In addition, the orbital inflammation was partnered with the onset of muscle edema and formation of brown adipose tissue in TSHR-immunized mice, effects that were abrogated upon application of linsitinib. Conclusion: In summary, we demonstrate the development of GD and TED in a mouse model upon immunization against the TSHR. The IGF-1R antagonist linsitinib blocks the development of the local pathologies of GD and TED in an early and late phase of the autoimmune disorder and also prevents development of the autoimmune response. We show that treatment of immunized mice with linsitinib after disease onset significantly limited the severity of the disease, indicating the clinical significance of the findings and providing a path to therapeutic intervention of Graves’ Disease. Our data support the use of linsitinib as a novel first line treatment of thyroid eye disease. Presentation: Saturday, June 17, 2023

Linsitinib, an IGF-1R inhibitor, attenuates disease development and progression in a model of thyroid eye disease.

Graves' disease (GD) is an autoimmune disorder caused by autoantibodies against the thyroid stimulating hormone receptor (TSHR) leading to overstimulation of the thyroid gland. Thyroid eye disease (TED) is the most common extra thyroidal manifestation of GD. Therapeutic options to treat TED are very limited and novel treatments need to be developed. In the present study we investigated the effect of linsitinib, a dual small-molecule kinase inhibitor of the insulin-like growth factor 1 receptor (IGF-1R) and the Insulin receptor (IR) on the disease outcome of GD and TED. Linsitinib was administered orally for four weeks with therapy initiating in either the early ("active") or the late ("chronic") phases of the disease. In the thyroid and the orbit, autoimmune hyperthyroidism and orbitopathy were analyzed serologically (total anti-TSHR binding antibodies, stimulating anti TSHR antibodies, total T4 levels), immunohistochemically (H&E-, CD3-, TNFa- and Sirius red staining) and with immunofluorescence (F4/80 staining). An MRI was performed to quantify in vivo tissue remodeling inside the orbit. Linsitinib prevented autoimmune hyperthyroidism in the early state of the disease, by reducing morphological changes indicative for hyperthyroidism and blocking T-cell infiltration, visualized by CD3 staining. In the late state of the disease linsitinib had its main effect in the orbit. Linsitinib reduced immune infiltration of T-cells (CD3 staining) and macrophages (F4/80 and TNFa staining) in the orbita in experimental GD suggesting an additional, direct effect of linsitinib on the autoimmune response. In addition, treatment with linsitinib normalized the amount of brown adipose tissue in both the early and late group. An in vivo MRI of the late group was performed and revealed a marked decrease of inflammation, visualized by 19F MR imaging, significant reduction of existing muscle edema and formation of brown adipose tissue. Here, we demonstrate that linsitinib effectively prevents development and progression of thyroid eye disease in an experimental murine model for Graves' disease. Linsitinib improved the total disease outcome, indicating the clinical significance of the findings and providing a path to therapeutic intervention of Graves' Disease. Our data support the use of linsitinib as a novel treatment for thyroid eye disease.

The role of oxidative stress in the pathogenesis of Graves’ orbitopathy

Graves' disease (GD) is a chronic autoimmune condition, in which the anti-thyroid stimulating hormone receptor antibodies (TRAb) activate the thyrotropin receptor (TSHR) located on thyrocytes, leading to excessive thyroid hormone production. TSHR is also expressed in extrathyroidal tissues, in particular, within the orbit. The serum levels of TRAb corelate with severity and activity of thyroid orbitopathy (TO). TO is the most common extrathyroidal manifestation of GD. It is an autoimmune inflammation of orbital tissues, that is, extraocular muscles, orbital adipose tissue or a lacrimal gland. Increased orbital fibroblast and adipocyte proliferation, overproduction of glycosaminoglycans, as well as extraocular muscle oedema result in an increased orbital tissue volume and trigger the onset of TO symptoms. The pathophysiology of TO is complex and has not been fully unexplained to date. Orbital fibroblasts show expression of the TSHR, which is the main target of autoimmunity. It has been hypothesised that T-cell activation induced by orbital receptor stimulation by the target antibody results in orbital tissue infiltration, triggering a cascade of events which leads to the production of cytokines, growth factors and reactive oxygen species (ROS). ROS cause damage to many components of the cell: the cell membrane through the peroxidation of lipids and proteins leading to a loss of their function and enzymatic activity. Oxidative stress leads to activation of the antioxidant system which operates through two mechanisms: enzymatic and non-enzymatic. Assessment of the concentration of oxidative stress markers and the concentration or activity of antioxidative system parameters enables evaluation of oxidative stress severity, which in the future may be utilized for assessment of treatment efficacy and prognosis in patients with active OT.

Clinical Features and Associated Risk Factors for Thyroid Eye Disease Among Goiter Patients Who Attended Jimma University Medical Center Surgical Referral Clinic, Jimma Town, Ethiopia

Introduction Eye involvement is the most common extrathyroidal manifestation of Graves disease. Regarding our study area, there is no previous study done on the prevalence of thyroid eye disease among goiter patients. Methods: Institution-based cross-sectional study was carried out among 211 patients seen in Jimma University Medical Center surgical referral clinic from April to July 2018. The collected data were coded and entered into Epi data version 3.1 and analyzed using SPSS version 20. Variables having a P-value of less than 0.25 in the bivariate analyses were entered into a multivariable regression analysis to control the confounding variables. Results: Two hundred eleven goiter patients presented for care at JUMC surgical referral clinic over the 3 months study period; 57 (27%) of them were found to have thyroid eye disease. Lid retraction (40; 19%) was the most frequently observed sign of thyroid eye disease, whereas proptosis was found only in one case and no exposure to keratopathy or dysthyroid optic neuropathy was found. The factors that had statistically significant association with the prevalence of thyroid eye disease were thyroid dysfunction [adjusted odds ratio (AOR) = 2.781, (95% CI, 1.362–5.678) P = 0.005], smoking [AOR = 6.391, (95% CI, 1.868–21.860) P = 0.003], high blood pressure [AOR = 2.062, (95% CI, 1.001–4.251] P = 0.050] and high pulse rate [AOR=2.277 (95% CI, 1.003–5.167) P = 0.049]. Conclusion: Thyroid eye disease among goiter patients is common and many patients are followed up for goiter.

Rola stresu oksydacyjnego w patogenezie orbitopatii Gravesa

Streszczenie Choroba Gravesa-Basedowa (chGB) jest przewlekłą chorobą autoimmunologiczną, której auto-antygenem jest receptor TSH (TSHR) umiejscowiony na tyreocytach, a jego pobudzenie przez przeciwciała przeciwko TSHR (TRAb) powoduje nadmierne wytwarzanie hormonów tarczycy. TSHR wykazuje także ekspresję w tkankach pozatarczycowych, przede wszystkim w tkankach oczodołu, a stężenie TRAb w surowicy krwi dodatnio koreluje z ciężkością oraz aktywnością orbitopatii tarczycowej (OT). OT jest najczęstszym pozatarczycowym objawem chGB. Jest to choroba autoimmunologiczna, w której dochodzi do zmian zapalnych w obrębie tkanek oczodołów, tj.: mięśniach okoruchowych, tkance tłuszczowej oczodołu czy gruczole łzowym. Wzrost proliferacji fibroblastów oczodołowych i adipocytów oraz nadmierne wytwarzanie glikozaminoglikanów, obrzęk mięśni okoruchowych zwiększają objętość tkanek oczodołu i powodują powstanie objawów klinicznych choroby. Patogeneza OT jest złożona i nadal pozostaje niewyjaśniona. Fibroblasty oczodołów wykazują ekspresję TSHR, który jest głównym miejscem ataku autoimmunologicznego. Zgodnie z szeroko akceptowaną hipotezą po pobudzeniu receptorów dochodzi do aktywacji limfocytów T, które naciekając tkanki oczodołu stymulują je do wytwarzania cytokin, czynników wzrostu oraz wolnych rodników tlenowych (WRT). WRT powodują uszkodzenie wielu składowych komórki m.in. błony komórkowej przez peroksydację lipidów oraz białek doprowadzając do utraty ich funkcji i aktywności enzymatycznej. Stres oksydacyjny uaktywnia układ antyoksydacyjny działający poprzez dwa mechanizmy: enzymatyczny oraz nieenzymatyczny. Ocena stężenia markerów stresu oksydacyjnego oraz stężenia lub aktywności parametrów układu antyoksydacyjnego umożliwia ocenę nasilenia stresu oksydacyjnego, co w przyszłości może być wykorzystywane do oceny skuteczności leczenia i rokowania u chorych z aktywną OT.

Approach to the patients with Graves' ophthalmopathy

Graves' ophthalmopathy(GO)is the most common extrathyroidal manifestation of Graves disease(GD). It is an organ-specific autoimmune disorder. The estimated incidence of GO in the general population is 16 women and 3 men per 100, 000 population every year. Approximately 3%-5% of patients with GO are exposed to the potential of losing their sight and requiring optimized medical intervention. For the clinicians it is helpful to assess the degree of activity and severity of GO; both are important in deciding whether a patient requires intervention and which type of intervention is indicated. These interventions include management of hyperthyroidism, measures to relieve local symptoms, immunosuppressive therapies for active moderate and severe GO, and finally rehabilitative surgery for inactive patients. Key words: Graves' ophthalmopathy; Immunosuppressive therapies; Orbital irradiation; Orbital decompression; Rehabilitative surgery

A Century of Hyperthyroidism at Mayo Clinic

From the Division of Endocrinology & Metabolism, Mayo Clinic, Jacksonville, FL (R.C.S.); and the Division of Endocrinology & Metabolism, Mayo Clinic, Rochester, MN (J.C.M.). H yperthyroidism was first described by Caleb Hillier Parry (1825), Robert Graves (1835), and Karl von Basedow (1840). At the beginning of the 20th century, the causes were poorly understood and treatment was limited to surgery because antithyroid drugs and radioactive iodine (RAI) were unavailable until the early 1940s. Because of high surgical mortality, treatment was often delayed until the condition was advanced, and a multistage procedure might be required. Initially, hot water was injected into the thyroid, then a thyroid artery was ligated, and subsequently one or both thyroid lobes were resected. Furthermore, critically ill patients who survived surgery risked postoperative death from thyroid storm. Understanding of the etiology, pathology, physiology, clinical manifestations, and management of hyperthyroidism has evolved over the past 100 years, and new insights continue to emerge. Mayo Clinic physicians and scientists, working across disciplines, have contributed importantly to understanding this illness. This review of the Mayo Clinic experience will highlight these achievements, including pathologic clarification of the most common forms of hyperthyroidism, isolation of a crystalline product of thyroid hormone, development of a basal metabolism laboratory, discovery of a method to reduce postoperative mortality, investigation of the kinetics of thyroid hormones using radioisotopes, development and/ or establishing the clinical utility of laboratory tests to diagnose and monitor therapy for hyperthyroidism, clinical characterization of extrathyroidal manifestations of Graves disease, surgical management of severe Graves ophthalmopathy, the role of orbital radiotherapy, and the pathogenesis of Graves ophthalmopathy.

The importance of an individual approach to Graves’ hyperthyroidism

Graves' disease (GD) is an autoimmune disorder characterized by the presence of circulating autoantibodies that stimulate the thyroid hormone receptor (TSHR), resulting in hyperthyroidism and goiter. GD may affect also other organs, leading to Graves' orbitopathy, Graves' dermopathy and acropachy. It is likely that the extrathyroidal manifestations of GD are due to autoimmunity against antigens common to the thyroid and other affected organs (for example TSHR). Although its exact etiology remains to be established, GD is believed to result from a complex interaction between genetic, environmental and endogenous factors. The clinical picture of GD is highly variable. Measurements serum levels of anti-TSHR autoantibodies (TRAb) and thyroid ultrasonography represent the most important diagnostic tests for GD. Existing treatment modalities for Graves' hyperthyroidism includes antithyroid drugs (ATDs), radioactive iodine, and surgery. The use of ATDs as the initial treatment option in GD is well accepted. However, the optimal treatment duration and the predictive marker of remission after ATDs therapy are still controversial. A high relapse rate after a course of ATDs (60-70%), implies the use of ablative treatments (radioactive iodine or surgery) that remove or decrease thyroid tissue leading to lifelong hypothyroidism. There is a lack of general agreement as to which therapy for Graves’ hyperthyroidism is the best as none is ideal and all may have severe side effects. Moreover, none of these treatments targets the autoimmune disease process. Therefore the treatment plan should be established individually and carefully discussed with the patient. Hopefully novel agents that might act on the autoimmune disease process will be approved for Graves' hyperthyroidism.

Medical Management of Extrathyroidai-Man I Festation of Graves Disease

To review preventive measures and the current medical management of extrathyroidal manifestation of Graves disease and to provide an overview of potential immune therapies. A literature review of investigative trials of treatments for Graves disease and its extrathyroidal manifestations. Given new knowledge of the stages of the autoimmune cascade responsible for the development of these extrathyroidal manifestations, the possibility has been raised of performing randomized trials of agents shown to provide benefits in other immune conditions. Two randomized trials on the efficacy of rituximab in moderate-to-severe Graves ophthalmopathy have reported conflicting results. Additional studies of rituximab and other agents are needed before they become routinely used in treating Graves disease. Meanwhile, the standard medical therapy for moderate-to-severe ophthalmopathy is intravenous (IV) or oral corticosteroids and, for dermopathy, local corticosteroid application with occlusive dressing. Because major adverse effects such as life-threatening hepatic failure can occur with very high doses of IV prednisolone, the cumulative total dose should not exceed 8 g.

Commentary: rituximab, adalimumab, etanercept, tocilizumab--are biologics the future for Graves' orbitopathy?

Graves' orbitopathy (GO) is the main extrathyroidal manifestation of Graves disease and a rare disease in its severe expressions. Moderate-to-severe GO represents a therapeutic challenge. Established nonsurgical treatments include glucocorticoids (most commonly given intravenously), cyclosporine, and orbital radiotherapy. However, results are not always satisfactory, and a relevant proportion of GO patients need some kind of rehabilitative surgery (orbital decompression, squint surgery, eyelid surgery) once GO is inactivated. Biological agents have been used in several autoimmune disorders, with contrasting results. Current better understanding of the pathogenesis of GO allows us to identify pathways that might be the target of biologics. T and B cells, cytokines, and peroxisome proliferator-activated receptor-γ might all be targeted by treatments. It is extremely difficult to design and perform sufficiently powered randomized controlled studies that may support the role of targeted therapies. For the time being, rituximab, a monoclonal antibody depleting CD20-positive B cells, appears the most promising agent, but so far its use relies on the results of small and uncontrolled studies.

Graves Orbitopathy: Update on Diagnosis and Therapy

Graves orbitopathy (GO) is an autoimmune disorder representing the most frequent extrathyroidal manifestation of Graves disease. It is rare, with an age-adjusted incidence of approximately 16.0 cases per 100,000 population per year in women and 2.9 cases per 100,000 population per year in men. GO is an inflammatory process characterized by edema and inflammation of the extraocular muscles and an increase in orbital connective tissue and fat. Despite recent progress in the understanding of its pathogenesis, GO often remains a major diagnostic and therapeutic challenge. It has become increasingly important to classify patients into categories based on disease activity at initial presentation. A Hertel exophthalmometer measurement of >2 mm above normal for race usually categorizes a patient as having moderate-to-severe GO. Encouraging smoking cessation and achieving euthyroidism in the individual patient are important. Simple treatment measures such as lubricants for lid retraction, nocturnal ointments for incomplete eye closure, prisms in diplopia, or botulinum toxin injections for upper-lid retraction can be effective in mild cases of GO. Glucocorticoids, orbital radiotherapy, and decompression/rehabilitative surgery are generally indicated for moderate-to-severe GO and for sight-threatening optic neuropathy. Future therapies, including rituximab aimed at treating the molecular and immunological basis of GO, are under investigation and hold promise for the future.

The Thyrocyte-Fibrocyte Link: Closing the Loop in the Pathogenesis of Graves’ Disease?

Graves’ disease (GD) is an antibody-driven autoimmune process affecting the thyroid gland and extrathyroidal target tissues in roughly 90% of the cases (1). Generation of activating autoantibodies against the TSH receptor (TSHR) leads to excessive thyroid hormone synthesis uniquely in GD (2).However, themechanismsunderlyingextrathyroidal tissue inflammation and remodeling remain uncertain, as does their relationshipwith theprocessesoccurring in the thyroid. Manifestations of GD include thyrotoxicosis and several extrathyroidal signs including Graves’ orbitopathy (GO), dermopathy, and acropachy (3). GO and dermopathy are connective tissue manifestations of GD. Tissue remodeling is a prominent feature of both and is apparently controlled by adaptive T cells. Lymphocytes and other bone marrow-derived cells recruited into the orbit appear to be the major effectors of autoagressive tissue destruction in GO. The most likely sequence of events is that T cells infiltrate the orbital and dermal connective tissue and respond to a depot of orbital/dermal autoantigens that display an identical structure to have epitopes that cross-react with a thyroid autoantigen (1–3). Orbital fibroblasts comprise a heterogeneous population of cells possessing divergent phenotypes and potential for differentiation. They represent a bimodal population of cells with regard to the surface display of the glycoprotein, Thy1. Moreover, they exhibit attributes differing from their nonorbital counterparts that may underlie anatomic-selective involvement of the orbit in GD (4). Thus, orbital fibroblasts exhibit a unique phenotype, including exaggerated responses to proinflammatory cytokines. Cytokines play a key role in the development of the extrathyroidal manifestations of GD. These molecules are produced in the orbit of GO patients by infiltrating inflammatory cells as well as orbital fibroblasts. Cytokines can modulate the immune reaction in GO by increasing major histocompatibility complex class II, adhesion molecules, CD40 (a member of the TNFreceptor superfamily), prostaglandin, and heat shock protein expression in the orbit, thereby having a role in localizing and augmenting the inflammatory response (5). Locally released cytokines, particularly IL-1, TNF, and interferon , stimulate fibroblast proliferation and also activate fibroblasts to secrete the hydrophilic glycosaminoglycans (GAG) that cause edema with consequent proptosis. CD40 engagement leads to substantial increases in GAG synthesis in orbital fibroblasts. Also, CD40 ligand up-regulates the synthesis of IL-1 , and blocking this cytokine with exogenous IL-1 receptor antagonist or with IL-1 neutralizing antibodies partially attenuates the induction of prostaglandin endoperoxide H synthase-2. Thus, the CD40/CD40 ligand bridge represents a potentially important activational pathway for orbital fibroblasts that may underlie their cross-talk within the gateway of B-T-cell communication. Finally, smoking may be linked to GO through the generation of partial hypoxia, which increases GAG synthesis by fibroblasts, and by direct effects of cigarette smoke constituents on fibroblast activation (3). The disordered accumulation of the GAG in orbital and dermal connective tissues leads to the distinctive histological features associated with GD-related GO and dermopathy (6). This often occurs in the context of dramatic inflammation and tissue remodeling, which is a prominent feature of the extrathyroidal manifestations of GD and is apparently driven by activated T cells. GAG take part in extracellular matrix organization, the regulation of cell proliferation and differentiation, and the regulation of diffusion of macromolecules through tissues, growth factor attachment, cell-to-cell interaction, and regulation of IL-1 production in local inflammatory response. Hyaluronic acid (HA) is the largest GAG molecule containing several

The Effect of Methylprednisolone Pulse Treatment on Cytokine Network in Graves Ophthalmopathy

The etiology of Graves ophthalmopathy (GO), representing the most common extrathyroidal manifestation of Graves disease, is multifactorial. Among multiple genetic, environmental, and endogenous factors, cytokines play a critical role in its etiopathogenesis. We studied an effect of glucocorticoid therapy on the serum IL-6, IL-4, and IL-13 levels in 18 GO patients. All the patients presented euthyroid GO with over 4 points according to the CAS classification (range 4–6; mean 4.94). The patients were treated with methylprednisolone (1 g every second day for three times) followed by 6 months oral prednisone (60 mg/day, with gradual reduction). The clinical examination (Clinical Activity Score and the GO severity by modified NOSPECS classification) and measurement of anti-TPO, anti-TG, anti-TSHR (TRAK), IL-6, IL-4, as well as IL-13 serum levels were performed before, after 2 weeks, and after 6 months of the glucocorticoid therapy. Significant serum IL-6 increases (p < 0.001) and moderate serum IL-4 and IL-13 increases (p < 0.05) were found in GO patients compared with healthy controls. After 2 weeks of the therapy, the serum IL-6 levels decreased in majority of the patients, however after 6-month observation, lower serum IL-6 levels were only in 8 patients who seemed to respond clinically to the therapy (mean value of the Clinical Activity Score decreased from 4.5 before the therapy initiation to 1.25 after 6 months of the glucocorticoid therapy). No changes in IL-4 and IL-13 serum levels during the therapy were observed. Statistical analysis revealed a good correlation between serum IL-6 level and the Clinical Activity Score (p < 0.01). Based on the obtained data, we conclude that IL-6 plays an important role in GO. It seems that IL-6 may serve as a useful factor in the inflammatory events of GO.

Pathogenesis of Graves ophthalmopathy: the role of orbital thyroid-stimulating hormone receptor expression

The thyroid-stimulating hormone, or thyrotropin, receptor (TSHr) is the autoantigen against which the autoimmune response is directed in Graves hyperthyroidism. The close clinical associations between hyperthyroidism, Graves ophthalmopathy (GO), and pretibial dermopathy (PTD) led to the hypothesis that these conditions represent different manifestations of the same autoimmune disease. This paper reviews recent literature concerning the potential role of TSHr as an autoantigen in the pathogenesis of the extrathyroidal manifestations of Graves disease. Recent studies from several laboratories suggested that low-abundance TSHr messenger RNA and protein are present in normal connective and adipose tissues from many anatomic sites. In addition, increased expression of this receptor has been demonstrated in orbital and dermal tissues from patients with GO and PTD. In normal individuals, low-abundance TSHr expression in connective tissues throughout the body may have little physiologic relevance. However, in the setting of Graves disease with circulating antibodies and T cells directed against this antigen, a generalized, subclinical, connective tissue inflammation may develop. On this background, local environmental factors affecting the orbit and pretibial skin may contribute to the development of clinical disease at these sites. Alternately, locally enhanced expression of TSHr at the sites of clinical disease may not be directly involved in pathogenesis but could be secondary to the ongoing disease process and important in disease progression.

Igs from Patients with Graves’ Disease Induce the Expression of T Cell Chemoattractants in Their Fibroblasts

Thyroid-associated ophthalmopathy and dermopathy are connective tissue manifestations of Graves' disease (GD). Tissue remodeling is a prominent feature of both and is apparently driven by recruited T cells. In this study, we report that IgG isolated from patients with GD (GD-IgG) up-regulates T lymphocyte chemoattractant activity in GD-derived fibroblasts from orbit, thyroid, and several regions of skin. This chemoattractant activity, absent in fibroblasts from donors without known thyroid disease, is partially susceptible to neutralization by anti-IL-16 and anti-RANTES Abs. IL-16 is a CD4(+)-specific chemoattractant and RANTES is a C-C-type chemokine. IL-16 and RANTES protein levels, as determined by specific ELISAs, are substantially increased by GD-IgG in GD fibroblasts. Addition of the macrolide, rapamycin, to fibroblast culture medium blocked the up-regulation by GD-IgG of IL-16, implicating the FRAP/mTOR/p70(s6k) pathway in the induction of IL-16 expression. These findings suggest a specific mechanism for activation of fibroblasts in GD resulting in the recruitment of T cells. They may provide insight into a missing link between the glandular and extrathyroidal manifestations of GD.

Analysis of human thyrotropin receptor gene expression and immunoreactivity in human orbital tissue

The human thyrotropin receptor (hTSHR) represents an autoantigen that plays a central role in the hyperthyroidism of Graves' disease (GD). hTSHR transcripts have recently been detected by reverse transcription (RT)-PCR in various extrathyroidal tissues, suggesting that the hTSHR may be more widely distributed than previously thought, and that it may serve as a common antigen in the thyroidal and extrathyroidal manifestations of GD. Using techniques other RT-PCR, we examined whether RNA encoding hTSHR and hTSHR-specific immunoreactivity can be detected and localized in cultured orbital fibroblasts (OF), orbital connective tissue, extraocular muscle and various extraorbital tissues derived from both patients with Graves' ophthalmopathy (GO) and normal individuals. Using in situ hybridization with a digoxigenin-labeled antisense oligonucleotide probe specific for the extracellular domain of hTSHR, specific perinuclear and cytoplasmic hTSHR gene expression was detected in OF of patients with GO and, to a lesser degree, normal individuals. Using a highly sensitive immunostaining technique and a panel of monoclonal and polyclonal antibodies directed against different epitopes of recombinant hTSHR, distinct cytoplasmic hTSHR-like immunoreactivity was detected in methanol-fixed OF and orbital connective tissue, which was absent in abdominal fibroblasts, or when using isotype-matched non-immune immunoglobulins. Mouse monoclonal and pig polyclonal hTSHR antibodies detected cytoplasmic hTSHR-like immunoreactivity in perimysial fibroblasts within extraocular muscle, but not in extraocular muscle fibers. Immunocytochemical staining with rabbit polyclonal hTSHR antibody revealed, in addition, distinct cell surface-associated immunoreactivity in paraformaldehyde-fixed OF, but not in abdominal fibroblasts. Taken together, our results suggest that RNA encoding hTSHR is present and actively processed to immunoreactive hTSHR-like protein in OF residing within orbital connective tissue and extraocular muscle. These data support the concept that OF expressing intact or variant hTSHR may act as extrathyroidal targets for sensitized T-cells and immunoglobulins in GD.

Lack of an association between alleles of interleukin-1 alpha and interleukin-1 receptor antagonist genes and Graves' disease in a North American Caucasian population.

Although an association between the human leukocyte antigen (HLA) allele DR3 and Graves' disease (GD) is well documented, the potential role of non-HLA-linked alleles in susceptibility to GD is an area of active investigation. In an attempt to study the potential role of two non-HLA susceptibility alleles in GD and Graves' ophthalmopathy, we examined 286 North American Caucasian individuals (145 normal controls and 141 individuals with GD) for the presence of the A2 allele of the interleukin-1 (IL-1) receptor antagonist gene. In addition, we examined a subset of this population (83 normal controls and 89 individuals with GD) for a specific polymorphism within exon 5 of the IL-1 alpha gene. We found the A2 allelic frequencies (0.25 and 0.23, respectively) and carriage rates (43% and 41%, respectively) in the two groups to be nearly identical. However, findings in the subgroup of patients with the extrathyroidal manifestations of GD (Graves' ophthalmopathy, pretibial dermopathy, and acropachy) suggested a trend toward a higher prevalence of the A2 allele in patients with more severe disease. The allelic frequency (0.28) and carriage rate (47%) of the IL-1 alpha exon 5 polymorphism in individuals with GD were nearly identical to those of the control population (0.28% and 45%, respectively). In summary, we were unable to demonstrate an association between these alleles and GD in our study population. We conclude that neither the A2 allele of the IL-1 receptor antagonist gene nor the IL-1 alpha exon 5 polymorphism confers increased susceptibility to GD.