Both Th1- and Th2-derived cytokines in serum are elevated in Graves' ophthalmopathy

Thyroid stimulating immunoglobulin concentration is associated with disease activity and predicts response to treatment with intravenous methylprednisolone in patients with Graves' orbitopathy

Background

Thyroid stimulating immunoglobulins (TSI) play a central role in the pathogenesis of Graves' orbitopathy (GO), while soluble interleukin-2 receptor (sIL-2R) is a marker for T-cell activity. We investigated TSI and sIL-2R levels in relation to thyroid function, disease activity and severity and response to treatment with intravenous methylprednisolone (IVMP) in patients with GO.

Methods

TSI (bridge-based TSI binding assay), sIL-2R, TSH and fT4 levels were measured in biobank serum samples from 111 GO patients (37 male, 74 female; mean age 49.2 years old) and 25 healthy controls (5 male, 20 female; mean age 39.8 years old). Clinical characteristics and response to treatment were retrospectively retrieved from patient files.

Results

Higher sIL-2R levels were observed in GO patients compared to controls (p < 0.001). sIL-2R correlated with fT4 (r = 0.26), TSH (r = -0.40) and TSI (r = 0.21). TSI and sIL-2R concentrations were higher in patients with active compared to inactive GO (p < 0.001 and p < 0.05, respectively). Both TSI and sIL-2R correlated with total clinical activity score (CAS; r = 0.33 and r = 0.28, respectively) and with several individual CAS items. Cut-off levels for predicting active GO were 2.62 IU/L for TSI (AUC = 0.71, sensitivity 69%, specificity 69%) and 428 IU/mL for sIL-2R (AUC = 0.64, sensitivity 62%, specificity 62%). In multivariate testing higher TSI (p < 0.01), higher age (p < 0.001) and longer disease duration (p < 0.01) were associated with disease activity. TSI levels were higher in patients with a poor IVMP response (p = 0.048), while sIL-2R levels did not differ between responders and non-responders. TSI cut-off for predicting IVMP response was 19.4 IU/L (AUC = 0.69, sensitivity 50%, specificity 91%). In multivariate analysis TSI was the only independent predictor of response to IVMP (p < 0.05).

Conclusions

High TSI levels are associated with active disease (cut-off 2.62 IU/L) and predict poor response to IVMP treatment (cut-off 19.4 IU/L) in GO. While sIL-2R correlates with disease activity, it is also related to thyroid function, making it less useful as an additional biomarker in GO.

Molecular Biomarkers in Thyroid Eye Disease: A Literature Review

PURPOSE

Thyroid eye disease (TED) is the most common extrathyroidal manifestation of Graves disease. Patients may be severely affected with eyelid retraction, exophthalmos, diplopia, pain, and threatened vision. Autoantibodies against thyroid-stimulating hormone receptor and insulin-like growth factor 1 receptor have shown associations with pathophysiological and clinical traits. Autoantibodies against thyroid-stimulating hormone receptor is in current clinical use as biomarker, but not with unambiguous diagnostic performance. A biomarker with high diagnostic accuracy and/or prognostic capability would be of immense value in diagnosing TED, especially in subclinical cases or when TED precedes the thyroid dysfunction. This article is a literature review on molecular biomarkers of TED.

METHODS

A literature search was performed using PubMed and Embase. Studies on molecular biomarkers in blood, tear fluid, and urine were included in the review.

RESULTS

Forty-six papers were included, of which 30, 14, and 2 studies on biomarkers in blood, tears, and urine, respectively. Fourteen of the papers evaluated the diagnostic performance of various biomarkers, 12 in blood and 2 in tears. Most studies evaluated single biomarkers, but 3 tested a panel of several markers. Except for autoantibodies against thyroid-stimulating hormone receptor, the reported diagnostic performances for the biomarkers were not confirmed in independent cohorts. In 32 studies, no or insufficient performance data were given, but the findings indicated involvement of various biologic mechanisms in TED including inflammation, oxidative stress, fibrosis, lipid metabolism, and ocular surface microflora.

CONCLUSIONS

Currently, serum autoantibodies against thyroid-stimulating hormone receptor is the only molecular biomarker with clinical utility in patients with TED. Several potential biomarkers have been investigated, and particularly panels of multiple biomarkers in tears are promising. To improve patient care, biomarkers in TED should be studied further.

Macrophage-Orbital Fibroblast Interaction and Hypoxia Promote Inflammation and Adipogenesis in Graves' Orbitopathy

The inflammatory eye disease Graves' orbitopathy (GO) is the main complication of autoimmune Graves' disease. In previous studies we have shown that hypoxia plays an important role for progression of GO. Hypoxia can maintain inflammation by attracting inflammatory cells such as macrophages (MQ). Herein, we investigated the interaction of MQ and orbital fibroblasts (OF) in context of inflammation and hypoxia. We detected elevated levels of the hypoxia marker HIF-1α, the MQ marker CD68, and inflammatory cytokines TNFα, CCL2, CCL5, and CCL20 in GO biopsies. Hypoxia stimulated GO tissues to release TNFα, CCL2, and CCL20 as measured by multiplex enzyme-linked immunosorbent assay (ELISA). Further, TNFα and hypoxia stimulated the expression of HIF-1α, CCL2, CCL5, and CCL20 in OF derived from GO tissues. Immunofluorescence confirmed that TNFα-positive MQ were present in the GO tissues. Thus, interaction of M1-MQ with OF under hypoxia also induced HIF-1α, CCL2, and CCL20 in OF. Inflammatory inhibitors etanercept or dexamethasone prevented the induction of HIF-1α and release of CCL2 and CCL20. Moreover, co-culture of M1-MQ/OF under hypoxia enhanced adipogenic differentiation and adiponectin secretion. Dexamethasone and HIF-1α inhibitor PX-478 reduced this effect. Our findings indicate that GO fat tissues are characterized by an inflammatory and hypoxic milieu where TNFα-positive MQ are present. Hypoxia and interaction of M1-MQ with OF led to enhanced secretion of chemokines, elevated hypoxic signaling, and adipogenesis. In consequence, M1-MQ/OF interaction results in constant inflammation and tissue remodeling. A combination of anti-inflammatory treatment and HIF-1α reduction could be an effective treatment option.

Elevated expression of interleukin-27, IL-35, and decreased IL-12 in patients with thyroid-associated ophthalmopathy

PURPOSE

Thyroid-associated ophthalmopathy (TAO) is a chronic autoimmune disease. The interleukin-12 (IL-12) family includes IL-12, IL-23, IL-27, and IL-35, all of which play important roles in autoimmunity. Thus far, the relationship between IL-12, IL-27, and IL-35 and the TAO has not been evaluated.

METHODS

Seventy-five serum samples from patients with TAO were collected. Serum samples from 90 healthy controls (HC), 55 patients with Graves' disease (GD), 38 patients with uveitis (UV), 17 patients with Sjogren's syndrome (SS), and 65 patients with rheumatoid arthritis (RA) were collected as controls. The associations between IL-27, IL-35, IL-12, and other clinical parameters were analyzed.

RESULTS

Elevated serum levels of IL-27/IL-35 and decreased serum IL-12 levels were observed in TAO patients compared to those in HC (p < 0.001). For HC, we observed good diagnostic ability to predict TAO (area under the curve = 0.74, 0.78, and 0.78, for IL-27, IL-35, and IL-12, respectively). For other autoimmune diseases, IL-27, IL-35, and IL-12 had the ability to discriminate between UV, RA, and SS (area under the curve = 0.80, 0.83, and 0.85 for IL-27; 0.52, 0.69, and 0.67 for IL-35). The positive detection rates of IL-12 were significantly lower in the TAO group than in the UV and RA groups (p = 0.002, 0.01).

CONCLUSION

IL-12, IL-27, and IL-35 have the potential as biomarkers for TAO.

Association between Clinical Activity Score and Serum Interleukin-6, Interleukin-8 and Interleukin-10 during Systemic Glucocorticoid Treatment for Active Moderate-to-Severe Graves' Orbitopathy

Purpose: Some interleukins (ILs) play an important role in Graves' orbitopathy (GO) pathogenesis. We aimed to compare serum IL-6, IL-8 and IL-10 in GO patients, patients with Graves' disease (GD) without GO and healthy controls (HC); to follow IL changes during glucocorticoid (GC) treatment for GO; to examine associations between ILs and Clinical Activity Score (CAS).Materials and Methods: Thirty-one patients with active moderate-to-severe GO (GO⁽⁺⁾ group), 30 patients with GD without GO (GO^(-) group) and 30 HC were enrolled. At baseline, ILs were measured in all groups, CAS was evaluated in GO⁽⁺⁾ patients, who were then treated with systemic GCs for 12 weeks. ILs and CAS were reassessed after the first week of treatment (W2) and at the end of the therapy (W12).Results: At baseline, IL-6 was significantly higher in GO⁽⁺⁾ and GO^(-) patients, IL-8 - higher in GO^(-) patients and IL-10 - lower in GO⁽⁺⁾ patients compared to HC. Baseline ILs did not correlate with CAS. At W2, all ILs and CAS decreased significantly. At W12, CAS decreased further, IL-6 remained low, IL-8 and IL-10 returned to baseline. CAS reduction correlated positively with IL-6 reduction at W12 (ρ = 0.38, p = .04).GO⁽⁺⁾ patients with overall CAS reduction≥2 had higher baseline IL-6 (3.4 vs 2.6 pg/ml, p = .15), smaller IL-10 reduction at W2 (10.5 vs 18.2%, p = .09), lower IL-6 (1.4 vs 2.4 pg/ml, p < .01) and higher IL-6 reduction at W12 (48.6 vs 21.4%, p = .01) compared to patients with CAS reduction<2. Logistic regression analysis confirmed that overall CAS reduction≥2 was associated with higher baseline IL-6, lower IL-6 at W12 and smaller IL-10 reduction at W2 (R² = 0.66).Conclusions: Higher baseline IL-6, lower IL-6 at W12 and smaller IL-10 reduction at W2 were associated with higher probability of significant overall CAS reduction. IL-6 might be a potential additional marker for assessing disease activity.

Teprotumumab Treatment for Thyroid-Associated Ophthalmopathy

BACKGROUND

Thyroid-associated ophthalmopathy (TAO), an autoimmune process affecting the tissues surrounding the eye, most commonly develops in individuals with Graves' disease. It is disfiguring, can cause vision loss, and dramatically lessens the quality of life in patients. There has been an absence of approved medical therapies for TAO with proven effectiveness and safety in multicenter, placebo-controlled, and adequately powered clinical trials.

SUMMARY

The following is a brief overview of the rationale for developing a monoclonal antibody inhibitor of the insulin-like growth factor-I receptor into a treatment for TAO. This area of fundamental research has yielded an effective and safe medication, namely teprotumumab, based on two multicenter, placebo-controlled trials. Teprotumumab, marketed as Tepezza, has been approved recently by the US Food and Drug Administration for the treatment of TAO. Given its remarkable effectiveness, Tepezza is poised to become the first-line standard of care for TAO.

KEY MESSAGES

Introduction of Tepezza into our armamentarium of therapeutic strategies for TAO represents a paradigm shift in the management of the disease. I proffer that the drug will replace glucocorticoids as a first-line treatment for TAO.

Novel Approaches for Immunosuppression in Graves' Hyperthyroidism and Associated Orbitopathy

BACKGROUND

Both Graves' hyperthyroidism (GH) and Graves' orbitopathy (GO) are associated with significant adverse health consequences. All conventional treatment options have limitations regarding efficacy and safety. Most importantly, they do not specifically address the underlying immunological mechanisms. We aim to review the latest development of treatment approaches in these two closely related disorders.

SUMMARY

Immunotherapies of GH have recently demonstrated clinical efficacy in preliminary studies. They include ATX-GD-59, an antigen-specific immunotherapy which restores immune tolerance to the thyrotropin receptor; iscalimab, an anti-CD40 monoclonal antibody which blocks the CD40-CD154 costimulatory pathway in B-T cell interaction; and K1-70, a thyrotropin receptor-blocking monoclonal antibody. Novel treatment strategies have also become available in GO. Mycophenolate significantly increased the overall response rate combined with standard glucocorticoid (GC) treatment compared to GC monotherapy. Tocilizumab, an anti-interleukin 6 receptor monoclonal antibody, displayed strong anti-inflammatory action in GC-resistant cases. Teprotumumab, an anti-insulin-like growth factor 1 receptor monoclonal antibody, resulted in remarkable improvement in terms of disease activity, proptosis, and diplopia. Further, rituximab appears to be useful in active disease of recent onset without impending dysthyroid optic neuropathy.

KEY MESSAGES

Therapeutic advances will continue to optimize our management of GH and associated orbitopathy in an effective and safe manner.

Proteomics Screening of Differentially Expressed Cytokines in Tears of Patients with Graves' Ophthalmopathy

BACKGROUND

The current study aimed at exploring the cytokine profile in the tears of patients with Graves' ophthalmopathy (GO).

METHODS

Tears were sampled from the eyes of 7 patients with active GO and 7 healthy volunteers using filter paper. Then the levels of up to 34 cytokines in the tears of each subject were detected using high-throughput protein microarray technology in line with the introduction.

RESULTS

The results of cytokine protein microarray screening showed that 10 proteins, namely, CD40, CD40 Ligand, GITR, IL-12p70, IL-1 beta, IL-2, IL-21, IL-6, MIP-3 alpha and TRANCE, were overexpressed (with fold change >1.20) and 3 proteins, namely, GM-CSF, IL-1 sRI and IL-13 were downregulated (with fold change < 0.83) in GO patients. In addition, the protein levels of CD40 and CD40 ligand (CD40L) were significantly different between GO patients and healthy controls (P=0.028 and 0.011, respectively). Further Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of differently expressed proteins showed that these proteins were involved in biological functions including biological processes (positive regulation of cytokine production, JAK-STAT cascade and leukocyte proliferation), molecular functions (cytokine and growth factor receptors binding and cytokine activity), and other important pathways (cytokine-cytokine receptor interaction, JAK-STAT signaling pathway, IL-17 signaling pathway, NF-kappa B signaling pathway, Th17 cell differentiation, and intestinal immune network for IgA production), all of which might be involved in the pathology of GO.

CONCLUSION

Our cytokine protein microarray analysis indicated that several proteins were differentially expressed in GO patients, which provides potential targets for GO prevention.

Integrating Differential Gene Expression Analysis with Perturbagen-Response Signatures May Identify Novel Therapies for Thyroid-Associated Orbitopathy

Purpose

To evaluate the efficacy of Library of Integrated Network-based Cellular Signatures (LINCS) perturbagen prediction software to identify small molecules that revert pathologic gene signature and alter disease phenotype in orbital adipose stem cells (OASCs) derived from patients with thyroid-associated orbitopathy (TAO).

Methods

Differentially expressed genes identified via RNA sequencing were inputted into LINCS L1000 Characteristic Direction Signature Search Engine (L1000CDS²) to predict candidate small molecules to reverse pathologic gene expression. TAO OASC cell lines were treated in vitro with six identified small molecules (Torin-2, PX12, withaferin A, isoliquiritigenin, mitoxantrone, and MLN8054), and expression of key adipogenic and differentially expressed genes was measured with quantitative polymerase chain reaction after 7 days of treatment. OASCs were differentiated into adipocytes, treated for 15 days, and stained with Oil Red O (OD 490 nm) to evaluate adipogenic changes.

Results

The expression of key differentially expressed genes (IRX1, HOXB2, S100B, and KCNA4) and adipogenic genes (peroxisome proliferator activated receptor-γ, FABP4) was significantly decreased in TAO OASCs after treatment (P < .05). In treated TAO adipocytes (n = 3), all six tested small molecules yielded significant decrease (P < .05) in Oil Red O staining. In treated non-TAO adipocytes (n = 3), only three of the drugs yielded a significant decrease in Oil Red O staining.

Conclusions

Combining disease expression signatures with LINCS small molecule prediction software can identify promising preclinical drug candidates for TAO.

Translational Relevance

These findings may offer insight into future potential therapeutic options for TAO and demonstrate a streamlined model to predict drug candidates for other diseases.

Simultaneous measurement of twenty-nine circulating cytokines and growth factors in female patients with overt autoimmune thyroid diseases

Cytokines and growth factors participate in immune responses, and the pathogenesis of autoimmune diseases. Herein, we simultaneously examined differential levels of 29 circulating factors to determine their associations in female patients with overt autoimmune thyroid disease (AITD). We enrolled 40 patients with Graves' disease (GD), 20 patients with Hashimoto's thyroiditis (HT), and 14 healthy controls. Twenty-nine circulating factors were simultaneously measured. GD patients with low thyroid-stimulating hormone at the time of sample collection were defined as having active GD. B-cell activating factor (BAFF) levels were associated with GD and HT (p = .001 and .001, respectively) and interferon (IFN)-α levels were higher in the HT group than in the control group (p = .021). Significant associations of serum BAFF and tumour necrosis factor (TNF)-α levels with free thyroxin (FT4) were present in HT (r = -0.498, p = .026, and r = 0.544, p = .013, respectively). Meanwhile, there were significant associations of FT4 with interleukin (IL)-4 and eotaxin levels in GD (r = 0.354, p = .025 and r = 0.384, p = .014, respectively). In active GD, serum BAFF and eotaxin level were correlated with FT4 levels (r = 0.465, p = .034, and r = 0.463, p = .035, respectively). In conclusion, BAFF is the best circulating indicator to identify GD and HT among all chosen 29 biomarkers, and it could be used to predict the disease severity in HT and active GD. Meanwhile, IFN-α could be another reliable parameter for recognising HT.

Metabolic Imbalance and Vitamin D Deficiency in Type 1 Diabetes in the Algerian Population

BACKGROUND

We aimed to assess Vitamin D levels in patients with Type 1 Diabetes (T1D) and to investigate the correlation between vitamin D and metabolic imbalance.

MATERIAL AND METHODS

For our study, we selected thirty-one patients with T1D without complications and fifty-seven healthy controls. Diabetic patients were diagnosed using the criteria of the World Health Organization/American Diabetes Association. Vitamin D, Parathyroid Hormone (PTH), insulin and C peptide assay were performed using chimilunescence. Glucose level, lipid profile, glycated haemoglobin (HbA1c) and ionogram were also analysed.

RESULTS

Vitamin D, HbA1c and Gly levels were found to be significant in T1D patients than in controls (P<0.5). However, for PTH, no significant difference was observed (P > 0. 05) and the results show a non-significant difference of total cholesterol potassium, sodium, phosphor and calcium concentration averages.

CONCLUSION

Our results indicate that the deficiency of VD is associated with an increased risk of T1DM in Algerian population.

Differential profiling of lacrimal cytokines in patients suffering from thyroid-associated orbitopathy

The aim was to investigate the levels of cytokines and soluble IL-6R in the tears of patients with thyroid-associated orbitopathy (TAO) disease. Schirmer’s test was adopted to collect tears from TAO patients (N = 20, 17 women, mean age (±SD): 46.0 years (±13.4)) and healthy subjects (N = 18, 10 women, 45.4 years (±18.7)). Lacrimal cytokines and soluble IL-6R (sIL-6R) were measured using a 10-plex panel (Meso Scale Discovery Company) and Invitrogen Human sIL-6R Elisa kit, respectively. Tear levels of IL-10, IL-12p70, IL-13, IL-6 and TNF-α appeared significantly higher in TAO patients than in healthy subjects. Interestingly, IL-10, IL-12p70 and IL-8 levels increased in tears whatever the form of TAO whereas IL-13, IL-6 and TNF-α levels were significantly elevated in inflammatory TAO patients, meaning with a clinical score activity (CAS) ≥ 3, compared to controls. Furthermore, only 3 cytokines were strongly positively correlated with CAS (IL-13 Spearman coeff. r: 0.703, p = 0.0005; IL-6 r: 0.553, p = 0.011; IL-8 r: 0.618, p = 0.004, respectively). Finally, tobacco use disturbed the levels of several cytokines, especially in patient suffering of TAO. The differential profile of lacrimal cytokines could be useful for the diagnosis of TAO patients. Nevertheless, the tobacco use of these patients should be taken into account in the interpretation of the cytokine levels.

Clinical efficacy of Yingliu mixture combined with metimazole for treating diffuse goitre with hyperthyroidism and its impact on related cytokines

CONTEXT

Yingliu mixture was developed in 1990s by Affiliated Longhua Hospital of Shanghai University of Traditional Chinese Medicine, for treating diffuse goitre with hyperthyroidism (Graves' disease, GD). Former studies have shown Yingliu mixture combined with methimazole (Y-M) can effectively improve thyroid function and decrease thyrotropin-receptor antibody level. Furthermore, we researched its impact on related cytokines to prove that Y-M improve patients' immunity status.

OBJECTIVE

To observe the clinical efficacy of Y-M for treating GD.

METHODS

A total of 120 GD patients were randomly divided into two groups, the treatment and the control groups (n = 60). The treatment group's patients were treated with Y-M. The control group's patients were treated with methimazole alone. Yingliu mixture was orally administered, 25 mL three times daily. Methimazole was administered at 5-25 mg/day. After 12 weeks of the treatment, the cytokines, antibodies related to thyroid function, and Chinese medical syndromes were evaluated.

RESULTS

After the treatment, the free triiodothyronine and thyroxine levels in both groups decreased. The thyroid-stimulating hormone level increased in the treatment group. The thyrotropin-receptor antibody levels and TNF-α levels decreased in both groups. In the control group, IL-6 and IFN-γ levels were lower than that before the treatment. In the treatment group, CD4⁺ and CD25⁺ levels were higher than pretreatment levels, but IL-10 levels were reduced.

CLINICAL SYMPTOMS

the total CMS scores for both groups decreased.

CONCLUSIONS

The Y-M combination can improve thyroid function, and decrease autoantibodies, cytokines, and clinical symptoms, so its efficacy may surpass that of methimazole alone.

The thyroid, the eyes and the gut: a possible connection

INTRODUCTION

Graves' disease (GD) is an autoimmune disorder responsible for 60-90% of thyrotoxicosis, with an incidence of 1 to 2 cases per 1000 population per year in England. Graves' orbitopathy (GO) is the most frequent extrathyroidal manifestation, not provoked directly by abnormal thyroid hormone levels, but by the consequence of the underlying autoimmune process. The aetiology of autoimmune disorders is due to an interplay between susceptibility genes and environmental factors, such as infections and stress. What triggers the autoimmune reaction to a specific site of the body is not yet clearly understood. The lack of knowledge in GD and GO pathogenesis implicates therapies that only limit damage but do not prevent disease onset.

MATERIAL AND METHODS

We performed on PubMed and the Cochrane Library a literature search for the articles published until July 2016 by using the search terms 'graves disease' and 'microbiome', 'orbitopathy' and 'autoimmune pathogenesis'. Reference lists of relevant studies were hand-searched for additional studies.

CONCLUSION

In this scenario, a Marie Sklodowska-Curie funded project INDIGO ( http://www.indigo-iapp.eu/ ) is investigating the role of the gut bacteria in GD and GO pathogenesis. The gut is the first and the widest area of bacteria access, with the highest concentration of T cells in the human body and trained to react to microorganisms. Interestingly, all the environmental factors involved in GD and GO pathogenesis can alter the balance within the microorganisms located in the gut, and influence the immune system, in particular the proportions of regulatory Treg and inflammatory TH17 cells. It is hoped that investigating GD and GO pathogenesis from this novel aspect will identify new targets for prevention and treatment.

Advances in treatment of active, moderate-to-severe Graves' ophthalmopathy

Graves' ophthalmopathy is defined as autoimmune inflammation of extraocular muscles and orbital fat or connective tissue, usually in patients with Graves' disease. About one in 20 patients with Graves' hyperthyroidism has moderate-to-severe Graves' ophthalmopathy. Corticosteroids have been the mainstay of treatment, but new evidence about immune mechanisms has provided a basis to explore other drug classes. Intravenous methylprednisolone pulses are more effective and better tolerated than oral prednisone in the treatment of active, moderate-to-severe Graves' ophthalmopathy. Rituximab has also been suggested as a possible replacement for intravenous corticosteroids. Two randomised controlled trials of rituximab reached seemingly contradictory conclusions-rituximab was not better with respect to the primary outcome (clinical activity score) than placebo in one trial (which, however, was confounded by rather long Graves' ophthalmopathy duration), but was slightly better than intravenous methylprednisolone pulses in the other (disease flare-ups occurred only in the latter group). On the basis of evidence published so far, rituximab cannot replace intravenous methylprednisolone pulses, but could have a role in corticosteroid-resistant cases. Open-label studies of tumour-necrosis-factor-α blockade had limited efficacy, but other studies showed that interleukin-6 receptor antibodies were effective. Results of randomised controlled trials investigating the efficacy of the IGF-1 receptor antibody teprotumumab and the interleukin-6 receptor antibody tocilizumab are expected shortly. Approaches that target the causal mechanism of Graves' ophthalmopathy (antibodies or antagonists that block thyroid-stimulating-hormone receptors) also look promising.

The teleost head kidney: Integrating thyroid and immune signalling

The head kidney, analogous to the mammalian adrenal gland, is an organ unique for teleost fish. It comprises cytokine-producing lymphoid cells from the immune system and endocrine cells secreting cortisol, catecholamines, and thyroid hormones. The intimate organization of the immune system and endocrine system in one single organ makes bidirectional signalling between these possible. In this review we explore putative interactions between the thyroid and immune system in the head kidney. We give a short overview of the thyroid system, and consider the evidence for the presence of thyroid follicles in the head kidney as a normal, healthy trait in fishes. From mammalian studies we gather data on the effects of three important pro-inflammatory cytokines (TNFα, IL-1β, IL-6) on the thyroid system. A general picture that emerges is that pro-inflammatory cytokines inhibit the activity of the thyroid system at different targets. Extrapolating from these studies, we suggest that the interaction of the thyroid system by paracrine actions of cytokines in the head kidney is involved in fine-tuning the availability and redistribution of energy substrates during acclimation processes such as an immune response or stress response.

Th1, Th2, and Th17 Cytokine Involvement in Thyroid Associated Ophthalmopathy

To determine serum cytokine profiles in Graves' disease (GD) patients with or without active and inactive thyroid associated ophthalmopathy (TAO), we recruited 65 subjects: 10 GD only (without TAO), 25 GD + active TAO, 20 GD + TAO, and 10 healthy controls. Liquid chip assay was used to measure serum Th1/Th2/Th17 cytokines including IFN-γ (interferon-gamma), TNF-α (tumor necrosis factor-alpha), IL-1α (interleukin-1 alpha), IL-1Ra (IL-1 receptor antagonist), IL-2, IL-4, IL-6, and IL-17 and two chemokines: RANTES (regulated upon activation, normal T cell expressed and secreted) and IP-10 (IFN-γ-induced protein 10). Serum levels of TSH (thyroid stimulating hormone) receptor autoantibodies (TRAb) were measured using an enzyme linked immunosorbent assay. Compared with healthy controls, TAO patients showed significantly elevated serum levels of IFN-γ, TNF-α, IL-1α, IL-4, IL-6, IL-17, and IP-10. Comparing active and inactive TAO, serum Th1 cytokines IFN-γ and TNF-α were elevated in active TAO, while serum Th2 cytokine IL-4 was elevated in inactive TAO. Serum Th17 cytokine IL-17 was elevated in GD but reduced in both active and inactive TAO. A positive correlation was found between TRAb and IFN-γ, TNF-α, IL-1α, IL-2, IL-4, and IL-6. Taken together, serum Th1/Th2/Th17 cytokines and chemokines reflect TAO disease activity and may be implicated in TAO pathogenesis.

Simultaneous measurement of serum chemokines in autoimmune thyroid diseases: possible role of IP-10 in the inflammatory response

Autoimmune thyroid diseases (AITDs), including Graves' diseases (GD) and Hashimoto's thyroiditis (HT), are the most common autoimmune diseases, and are mainly mediated by T cells that produce cytokines and chemokines in abnormal amounts. Few reports have described the circulating chemokines active in AITDs. Recently, we used a new multiplex immunobead assay to simultaneously measure cytokines and chemokines in small volume serum samples from patients with AITDs. We measured 23 selected serum chemokines in patients with GD (n=45) or HT (n=26), and healthy controls (n=9). GD patients were further classified as either untreated, intractable, or in remission, while HT patients were classified as either hypothyroid or euthyroid. Of the 23 serum chemokines assayed, only the serum level of IP-10 (CXCL10/interferon-γ-inducible protein 10) was elevated, depending on disease activity, in GD or HT compared with healthy controls. However, the serum level of IP-10 was also increased in both untreated GD patients and hypothyroid HT patients, suggesting that levels of this cytokine may not be affected by disease specificity. In conclusion, autoimmune inflammation in patients with AITD is closely related to the level of the serum chemokine, IP-10. Therefore, IP-10 might be a good biomarker for tissue inflammation in the thyroid, but not a useful biomarker for predicting disease specific activity, the progression of AITDs, or responsiveness to treatment because of its independence from thyroid function or disease specificity.

Current concepts in the molecular pathogenesis of thyroid-associated ophthalmopathy

Graves' disease (GD) is a common autoimmune condition. At its core, stimulatory autoantibodies are directed at the thyroid-stimulating hormone receptor (TSHR), resulting in dysregulated thyroid gland activity and growth. Closely associated with GD is the ocular condition known as thyroid-associated ophthalmopathy (TAO). The pathogenesis of TAO remains enigmatic as do the connections between the thyroid and orbit. This review highlights the putative molecular mechanisms involved in TAO and suggests how these insights provide future directions for identifying therapeutic targets. Genetic, epigenetic, and environmental factors have been suggested as contributory to the development of GD and TAO. Thyroid-stimulating hormone receptor and insulin-like growth factor receptor (IGF-1R) are expressed at higher levels in the orbital connective tissue from individuals with TAO than in healthy tissues. Together, they form a functional complex and appear to promote signaling relevant to GD and TAO. Orbital fibroblasts display an array of cell surface receptors and generate a host of inflammatory molecules that may participate in T and B cell infiltration. Recently, a population of orbital fibroblasts has been putatively traced to bone marrow-derived progenitor cells, known as fibrocytes, as they express CD45, CD34, CXCR4, collagen I, functional TSHR, and thyroglobulin (Tg). Fibrocytes become more numerous in GD and we believe traffic to the orbit in TAO. Numerous attempts at developing complete animal models of GD have been largely unsuccessful, because they lack fidelity with the ocular manifestations seen in TAO. Better understanding of the pathogenesis of TAO and development of improved animal models should greatly accelerate the identification of medical therapy for this vexing medical problem.

Interferon-gamma in ascites could be a predictive biomarker of outcome in ovarian carcinoma

OBJECTIVE

The ovarian cancer-associated ascites is an ideal material for evaluating the interaction between the host immune system and cancer cells in the tumor micro-environment. The aim of this study was to investigate whether the selected target cytokine expression levels in ascites could serve as an immune biomarker for predicting outcomes in ovarian cancer.

METHODS

Eighty-eight specimens of ovarian cancer-associated ascites were evaluated to select the target cytokine by a cytokine profiling kit. The 144 total samples were subsequently analyzed for this target cytokine. The correlation between the target cytokine and clinical characteristics was analyzed.

RESULTS

Interferon-gamma (IFN-γ) was identified as the target cytokine. Higher levels of IFN-γ in the ascites of the tumor micro-environment were associated with advanced disease (p=0.012), higher tumor histological grading (p=0.004), and sub-optimal surgical status (p=0.040). By multivariate analysis, the adjusted hazard ratios (HRs) were 2.74 (95% confidence interval (CI) 1.85-4.05, p<0.001) for disease-free survival (DFS) and 1.72 (95% CI 1.01-2.93, p=0.048) for overall survival (OS) for a 10-fold increase in IFN-γ concentration in the ascites. An inverse dose-response relationship between IFN-γ level and survival was also noted (Ptrend<0.001 for DFS and Ptrend<0.042 for OS).

CONCLUSIONS

Patients with ovarian cancer and higher IFN-γ expression levels in cancer-associated ascites will have shorter DFS and OS. IFN-γ levels in the ascites may be a prognostic marker and a potential reference for immunotherapy targeting IFN-γ.

Relative levels of the inflammatory cytokine TNFα and the soluble CD40 ligand profile in serum correlate with the thyrotoxic activity of Graves' disease

BACKGROUND

Interactions between CD40 and its ligand (CD40L) have important roles in T-cell-dependent activation of B cells, which may be related to the thyrotoxic activity of Graves' disease (GD). Soluble forms of CD40 ligand (sCD40L) are released from activated T cells and platelets, and several types of inflammatory cytokines are increased in patients with hyperthyroid GD. The aim of this study was to assess sCD40L and other cytokines as clinical indicators of disease activity or as possible markers of remission in GD.

METHODS

Serum levels of sCD40L, interleukin 18 (IL-18), tumor necrosis factor-alpha (TNFα), and TNFα receptors 1 and 2 (TNFR1 and TNFR2) were investigated in patients with active GD (GD-A), intractable GD (GD-IT), inactive GD (GD-IA), GD in remission (GD-R), and Hashimoto's thyroiditis (HT), and in control subjects (CON).

RESULTS

Serum concentrations of sCD40L were higher in the GD-A and GD-IT groups than in the HT and CON groups. Similarly, serum concentrations of IL-18, which induces Th1 cytokines, such as interferon-γ, were higher in the GD-A and GD-IT groups than in all other groups. Serum levels of TNFR1 and TNFR2 were also significantly higher in the GD-A than in all other groups. The mean serum concentration of TNFα was higher in the GD-R compared with the GD-A and GD-IT groups, although the difference was not significant. Serum sCD40L concentrations in the GD-R group were lower than in the GD-A and GD-IT groups. Finally, the ratio of serum TNFα to sCD40L was higher in the GD-R group than in the GD-A and GD-IT groups. This is the first report that serum sCD40L is increased in active GD, and that the serum TNFα:sCD40L ratio is a marker for remission in GD.

CONCLUSIONS

Our results suggest that not only thyrotoxicosis, but also the activity of the immunoreaction presenting as anti-thyrotropin receptor antibodies (TRAb) titer in GD, affects inflammatory cytokine serum profiles. Serum profiles of cytokines vary in patients with GD depending on disease activity. An elevated serum TNFα:sCD40L ratio indicates declining disease activity and reflects a shift from Th2 to Th1 dominance, suggesting that suppression of sCD40L or increased production of TNFα is required to initiate or maintain remission of GD.

Graves' orbitopathy results in profound changes in tear composition: a study of plasminogen activator inhibitor-1 and seven cytokines

BACKGROUND

Secretion of cytokines and expression of cytokine receptors have been reported in the orbital connective tissue in Graves' orbitopathy (GO). Lacrimal glands are putative autoimmune targets, and changes in tear film and ocular surface have also been described. Our aim was to characterize the cytokine profile of tears in patients with Graves' disease (GD) with and without orbitopathy.

METHODS

Tear samples were collected from 54 eyes of GO patients (age 43.4±15.2 years), 18 eyes of GD patients (age 46.8±11.7 years), and 24 control eyes (age 38.6±13.8 years). Patients underwent ophthalmological examination including Clinical Activity Score (CAS). The level of interleukin (IL)-1β, IL-6, IL-13, IL-17A, IL-18, tumor necrosis factor (TNF)-α, and RANTES (regulated upon activation, normal T-cell expressed, and secreted) as well as plasminogen activator inhibitor-1 (PAI-1) were measured by multiplex bead array and release values were calculated.

RESULTS

The release of IL-1β, IL-6, IL-13, IL-17A, IL-18, TNF-α, and RANTES were significantly higher in GO patients compared to controls (p<0.05). There was a 2.5-fold increase of IL-6 release. No significant differences were found in cytokine release between the GO and GD groups. In the GO group, significant positive correlation was found between CAS and the release of IL-6 and PAI-1 into tears (r=0.27, p<0.05 and r=0.24, p<0.05, respectively). PAI-1 release was significantly higher in GO than in GD patients and was increased in both the GD and GO groups compared to controls.

CONCLUSIONS

Impaired cytokine balance has been observed in tears of GO patients. Secretion of IL-6 into tears might be a useful indicator of disease activity in GO.

Analysis of sFas IL-6 levels in thyroid-associated ophthalmopathy: Pre- or poststeroid pulse treatment

PURPOSE

To investigate whether serum levels of soluble Fas (sFas) and interleukin-6 (IL-6) could function as an index of the efficacy of steroid pulse treatment, we examined the serum level of these proteins before and after steroid pulse treatment in thyroid-associated ophthalmopathy patients.

METHODS

We gathered the blood of thyroid-associated ophthalmopathy patients before or after steroid pulse treatment, obtained serum with a centrifuge, and measured the serum levels of sFas and IL-6 by enzyme-linked immunosorbent assay (ELISA).

RESULTS

There was no difference in serum IL-6 value between pre- and poststeroid pulse treatment. Serum sFas value was significantly decreased in both pre- and poststeroid pulse treatment. Furthermore, there was a recognizable improvement in the degree of the extraocular muscle thickening after treatment in cases in whom the serum sFas value was lower than 3 ng/ml prior to the beginning of the therapy. In patients who had a serum sFas value of more than 3 ng/ml, there was no improvement in the degree of thickening of the extraocular muscle.

CONCLUSIONS

Serum level of sFas is an accurate index of the outcome of steroid pulse treatment in thyroid-associated ophthalmopathy and may become a useful index to gauge the status of convalescence.

Cytokines (interferon-γ and tumor necrosis factor-α)-induced nuclear factor-κB activation and chemokine (C-X-C motif) ligand 10 release in Graves disease and ophthalmopathy are modulated by pioglitazone

Until now, the following are not known: (1) the mechanisms underlying the induction of chemokine (C-X-C motif) ligand 10 (CXCL10) secretion by cytokines in thyrocytes; (2) if pioglitazone is able, like rosiglitazone, to inhibit the interferon (IFN)-γ-induced chemokine expression in Graves disease (GD) or ophthalmopathy (GO); and (3) the mechanisms underlying the inhibition by thiazolidinediones of the cytokines-induced CXCL10 release in thyrocytes. The aims of this study were (1) to study the mechanisms underlying the induction of CXCL10 secretion by cytokines in GD thyrocytes; (2) to test the effect of pioglitazone on IFNγ-inducible CXCL10 secretion in primary thyrocytes, orbital fibroblasts, and preadipocytes from GD and GO patients; and (3) to evaluate the mechanism of action of thiazolidinediones on nuclear factor (NF)-κB activation. The results of the study (1) demonstrate that IFNγ + TNFα enhanced the DNA binding activity of NF-κB in GD thyrocytes, in association with the release of CXCL10; (2) show that pioglitazone exerts a dose-dependent inhibition on IFNγ + TNFα-induced CXCL10 secretion in thyrocytes, orbital fibroblasts, and preadipocytes, similar to the effect observed with rosiglitazone; and (3) demonstrate that thiazolidinediones (pioglitazone and rosiglitazone) act by reducing the IFNγ + TNFα activation of NF-κB in Graves thyrocytes. To the best of our knowledge, this is the first study showing that cytokines are able to activate NF-κB in Graves thyrocytes and a parallel inhibitory effect of pioglitazone both on CXCL10 chemokine secretion and NF-κB activation. Future studies will be needed to verify if new targeted peroxisome proliferator-activated receptor-γ activators may be able to exert the anti-inflammatory effects without the risk of expanding retrobulbar fat mass.

Thyroid-associated orbitopathy: Current insights into the pathophysiology, immunology and management

Half the patients suffering from Graves' disease develop thyroid-associated orbitopathy (TAO). The severity of TAO varies considerably with a mild form characterized by dry eyes and discomfort to the severe form with sight-threatening exposure keratopathy and optic neuropathy. The pathogenesis and immunologic mechanisms underlying Graves' disease and TAO is unknown, however, advances toward this understanding have indicated a prominent role of orbital fibroblasts, T cells and B cells. These advances have led to novel strategies for clinical treatment using immunomodulatory modalities. Initial results included use of infliximab and etanercept (anti-TNF agents), but currently there is an increasing interest in anti-B cell (Rituximab) therapy. Rituximab has shown promising results in progressive, sight-threatening TAO. It has also shown encouraging results in halting or slowing the disease process in patients unresponsive to corticosteroids. The primary advantage of these immunomodulatory agents is based upon targeting the molecular mediators of the disease and avoiding the potential side effects of non-specific therapies.

A stimulatory thyrotropin receptor antibody (M22) and thyrotropin increase interleukin-6 expression and secretion in Graves' orbital preadipocyte fibroblasts

BACKGROUND

Patients with Graves' ophthalmopathy (GO) have circulating autoantibodies directed against the thyrotropin receptor (TSHR) and elevated levels of the proinflammatory cytokine interleukin-6 (IL-6) in both serum and orbital tissues. We hypothesized that these autoantibodies might increase IL-6 expression and secretion in preadipocyte fibroblasts and adipocytes from patients with GO, and thus directly impact the clinical activity of the disease.

METHODS

IL-6 mRNA levels were measured in cultures of GO orbital preadipocytes (n = 3) treated during adipocyte differentiation with a monoclonal stimulatory TSHR antibody (M22; 10 ng/mL), IL-6 (1 ng/mL), or TSH (10 U/L). Additionally, levels of IL-6 protein secretion were assessed after adipocyte differentiation in orbital cultures exposed to TSH or M22 for 24 or 48 hours (n = 8). IL-6 mRNA levels were also measured in orbital adipose tissue specimens from well-characterized GO patients (n = 9) and normal individuals (n = 9).

RESULTS

Treatment of GO orbital preadipocyte cultures with IL-6, TSH, or M22 during adipocyte differentiation resulted in increased IL-6 mRNA levels (3.1-fold, 2.9-fold, and 2.7-fold, respectively; p < 0.05). Treatment of orbital cultures with M22 or TSH after adipocyte differentiation enhanced the release of IL-6 protein into the medium at both 24 and 48 hours for TSH (mean 1.9- and 2.3-fold; p = 0.002 and 0.015, respectively) and at 48 hours for M22 (mean 2.0-fold; p = 0.005). In addition, we found mean IL-6 mRNA levels to be significantly increased in GO orbital adipose tissue specimens (10-fold; p < 0.01), primarily attributable to high levels in three of the four patients with clinical activity scores >or=5.

CONCLUSIONS

Both TSH and M22 increase IL-6 expression in orbital preadipocyte fibroblasts and IL-6 secretion by mature adipocytes. These results suggest that circulating TSHR autoantibodies in GO might play a direct role in the clinical activity of the disease.

Association of G-174C Polymorphism of the Interleukin-6 Gene Promoter with Graves' Ophthalmopathy

Interleukin-6 (IL-6) may play an important role in the pathogenesis of Graves' ophthalmopathy (GO). The aim of this study was to analyze the association of IL-6 gene promoter polymorphism, at position - 174 (G --> C, termed as G-174C), which may affect IL-6 production, with the development of GO. The G-174C polymorphism was determined in 279 Polish-Caucasian patients with Graves' disease (GD), of which 108 had clinically evident ophthalmopathy (NOSPECS class III or higher) and 186 healthy Polish adults. In patients with GD, the frequencies of the C allele (45 vs 42%; P = 0.35) and C/C genotype (20 vs 15%; P = 0.13) were not significantly different compared to controls. Subdividing patients with GD for the presence of eye disease revealed that the C allele (44 vs 45%; P = 0.76) and C/C genotype (20 vs 20%; P = 0.92) were equally distributed in patients with or without ophthalmopathy. There was also no association between the G-174C polymorphism and the severity of eye changes. Finally, IL-6 genotypes were not associated with laboratory findings (thyroid volume, serum IL-6 and thyroid autoantibodies levels) in patients with GD at diagnosis. Our results suggest that G-174C polymorphism of the IL-6 gene does not contribute to the development and severity of GO.

Cytokines in Thyroid Autoimmunity

The role of cytokines in the pathogenesis of autoimmune thyroid disease (ATD) has been extensively investigated over the past years. In patients with ATD, these molecules can be found in both the thyroid and sites of extrathyroidal complications of the disease. Cytokines can affect the autoimmune process through a number of mechanisms including recruitment of inflammatory cells and upregulation of molecules essential for perpetuation of the inflammatory response in the affected site. In addition, cytokines can interfere with thyroid hormone synthesis, implicating them directly in thyroid dysfunction found in ATD patients. Also, these molecules can modulate the function of cells in orbital tissue, which results in localised oedema, indicating a central role for cytokines in the development of proptosis, the cardinal feature of thyroid associated ophthalmopathy.

Immunohistochemical Analysis of Orbital Connective Tissue Specimens of Patients With Active Graves Ophthalmopathy

PURPOSE

To explore the immune mechanism of Graves ophthalmopathy (GO) by analyzing infiltrating cells in orbital connective tissue (OCT) specimens of patients with active GO using immunohistochemical methods.

METHODS

Five OCT specimens obtained from patients with active GO and five control specimens obtained from forensic cadavers who died from nonmedical reasons were stained with anti-CD3, CD4, CD8, CD45RO, HLA-Dr, CD25, and TNF-alpha monoclonal antibodies. Positively stained cells were counted and results were interpreted as cell counts/mm2. Four of five GO patients had never been treated with any immunomodulating therapy. Only one had received oral prednisolone prior to tissue sampling, but this treatment had ceased 5 months before surgery.

RESULTS

The retro-orbital tissue specimens obtained from forensic cadavers did not show any significant positive staining for any monoclonal antibody tested. However, the specimens from GO patients showed positively stained means of 36.66 +/- 4.61 HLA-Dr+, 12.8 +/- 3.42 CD8+, 11.8 +/- 1.78 CD4+, 16.6 +/- 1.81 CD3+, 21.2 +/- 3.12 CD45RO+, 10.4 +/- 2.07 TNF-alpha+, 7.2 +/- 1.48 CD25+, 3.2 +/- 1.09 CD4+CD8+, 4.6 +/- 1.67 CD4+CD45RO+, 2.8 +/- 0.83 CD8+CD45RO+, 1.6 +/- 0.89 CD4+CD25+, and 1.8 +/- 1 0.83 CD8+CD25+ cells/mm2.

CONCLUSIONS

Our study supports that most of the infiltrating lymphocytic cells in the active stage of GO are T cells, and a significant proportion of them are CD45RO+ cells. Infiltration of OCT by HLA-Dr+, CD25+, and TNF-alpha cells suggests that Th1-type immune reaction with the interference of proinflammatory cytokine(s) (TNF-alpha) may be important in the pathogenesis of disease. Further studies are needed to understand the disease pathogenesis and may provide a scientific basis for future treatment alternatives for the disease (e.g., anti-cytokine treatment).

The relationship between thyroid function, serum monokine induced by interferon gamma and soluble interleukin-2 receptor in thyroid autoimmune diseases

Interactions between cytokines play an important role in the development of thyroid autoimmunity. Using enzyme-linked immunosorbent assay we investigated serum concentrations of soluble interleukin-2 receptor (sIL-2R), interferon-gamma, tumour necrosis factor (TNF)-alpha, interleukin (IL)-10, CD30, monokine induced by interferon-gamma (MIG), cytotoxic T lymphocyte antigen-4 and markers of apoptosis decoy receptor 3 and Bcl-2 in 28 patients with hyperthyroid Graves' disease (GD), 24 patients with untreated Hashimoto's thyroiditis (HT) and 15 healthy controls. TNF-alpha, IL-10 and sIL-2R were higher in GD compared with HT and controls (TNF-alpha: 8.79 in GD versus 2.54 pg/ml in HT, P = 0.01; IL-10: 10.00 versus 3.10 versus 3.10 pg/ml, P(1) < 0.001, P(2) = 0.005; sIL-2R: 1.26 versus 0.64 versus 0.46 ng/ml, P < 0.001). MIG and CD30 were higher in HT compared with controls (649.22 +/- 262.55 versus 312.95 +/- 143.35 pg/ml, P = 0.037, 6.57 +/- 2.35 versus 3.03 +/- 1.04 U/ml, P = 0.036 respectively). In GD sIL-2R decreased when the euthyroid state was achieved (1.31 +/- 0.64 versus 0.260 +/- 0.11, n = 12, P < 0.001). sIL-2R correlated positively with free thyroxine (FT4) (R = 0.521, P = 0.000) and negatively with thyroid stimulating hormone (TSH) (R = -0.472, P = 0.00132). MIG correlated negatively with FT4 (R = -0.573, P = 0.00234) and positively with TSH (R = 0.462, P = 0.0179). The results suggest that serum concentrations of sIL-2R and MIG are related to thyroid function rather than to activation of autoimmunity.

Biologic therapeutics in thyroid-associated ophthalmopathy: translating disease mechanism into therapy

Graves' disease (GD) is a systemic autoimmune disease which targets the thyroid, orbit, and skin. Thyroid-associated ophthalmopathy (TAO) refers specifically to the orbital and periorbital manifestations of GD. Several important concepts have emerged from our enhanced understanding of the molecular mechanisms of the disease. Considerable debate remains concerning the specific identity and roles of inflammatory T-cell subsets, soluble and contact-mediated signalling, and autoantigens driving TAO. However B and T lymphocytes appear central in the process through production of disease mediators including activating autoantibodies to the thyrotropin receptor and insulin-like growth factor-1 receptor; cytokines including IL-1beta, IL-6, and IL-16; and chemokines including RANTES. Many of these molecules appear central to the inflammation, accumulation of extracellular matrix macromolecules, and fibrosis in the disease. Novel therapeutics targeting other autoimmune diseases may provide an opportunity for disrupting disease pathogenesis. It is imperative that agents targeting B-and T-cell functions be further evaluated in the treatment of aggressive forms of TAO utilizing multicenter clinical trials that allow adequate statistical power and sample size.

Unique attributes of orbital fibroblasts and global alterations in IGF-1 receptor signaling could explain thyroid-associated ophthalmopathy

Tissue remodeling associated with thyroid-associated ophthalmopathy (TAO) involves the complex interplay between resident cells (endothelium, vascular smooth muscle, extraocular muscle, and fibroblasts) and those recruited to the orbit, including members of the "professional" immune system. Inflammation early in the disease can later culminate in fibrosis and diminished extraocular muscle motility. TAO remains a poorly understood process, in large part because access to tissues early in the disease is limited and because no robust and complete animal models of Graves' disease have yet been devised. Remaining uncertainty as to the identity of a pathogenic autoantigen(s) that underlies lymphocyte trafficking to the orbit complicates matters. These limitations in our understanding of extrathyroidal Graves' disease have resulted in poorly served patients with severe TAO. Therapies have targeted symptoms rather than the underlying disease processes. Our laboratory group has focused over the last several years on defining the peculiarities of the human orbital fibroblasts as a strategy for shedding more light on the pathologies occurring in TAO. We have reasoned that unique properties of these cells might ultimately prove the basis for why the manifestations of Graves' disease occur in an anatomically selective manner. In this brief review we attempt to survey our findings. We believe that they might provide a "roadmap" for further discovery into the pathogenesis of TAO. Clearly, more questions remain than those thus far answered.

Interrelationship among asthma, atopy, and helminth infections

To describe the principal evidence in the literature regarding the interrelationship among helminth infections, atopy, and asthma, a nonsystematic review of the literature was conducted. Among the publications on the subject, we found a number in which there was controversy regarding the capacity of geohelminth infections to inhibit responsiveness to skin allergy tests and to minimize the symptoms of allergic diseases. However, although small in number, studies of patients infected with Schistosoma spp. suggest that these helminths can inhibit the responsiveness to skin allergy testing and minimize asthma symptoms. Evidence provided by in vitro studies suggests that helminthiases inhibit T helper 1- and T helper 2-type immune responses. This opens new therapeutic possibilities for the treatment of immune system diseases.

Role of chemokines in endocrine autoimmune diseases

Chemokines are a group of peptides of low molecular weight that induce the chemotaxis of different leukocyte subtypes. The major function of chemokines is the recruitment of leukocytes to inflammation sites, but they also play a role in tumoral growth, angiogenesis, and organ sclerosis. In the last few years, experimental evidence accumulated supporting the concept that interferon-gamma (IFN-gamma) inducible chemokines (CXCL9, CXCL10, and CXCL11) and their receptor, CXCR3, play an important role in the initial stage of autoimmune disorders involving endocrine glands. The fact that, after IFN-gamma stimulation, endocrine epithelial cells secrete CXCL10, which in turn recruits type 1 T helper lymphocytes expressing CXCR3 and secreting IFN-gamma, thus perpetuating autoimmune inflammation, strongly supports the concept that chemokines play an important role in endocrine autoimmunity. This article reviews the recent literature including basic science, animal models, and clinical studies, regarding the role of these chemokines in autoimmune endocrine diseases. The potential clinical applications of assaying the serum levels of CXCL10 and the value of such measurements are reviewed. Clinical studies addressing the issue of a role for serum CXCL10 measurement in Graves' disease, Graves' ophthalmopathy, chronic autoimmune thyroiditis, type 1 diabetes mellitus, and Addison's disease have been considered. The principal aim was to propose that chemokines, and in particular CXCL10, should no longer be considered as belonging exclusively to basic science, but rather should be used for providing new insights in the clinical management of patients with endocrine autoimmune diseases.

T helper type 1 and type 2 cytokines exert divergent influence on the induction of prostaglandin E2 and hyaluronan synthesis by interleukin-1beta in orbital fibroblasts: implications for the pathogenesis of thyroid-associated ophthalmopathy

Thyroid-associated ophthalmopathy (TAO) is an autoimmune component of Graves' disease characterized by intense inflammation in the setting of volume expansion. At the heart of orbital susceptibility to Graves' disease appears to be the peculiar phenotype of orbital fibroblasts that, when activated by IL-1beta and other proinflammatory cytokines, produce excess prostaglandin E2 (PGE2) and hyaluronan. T helper type 1 (Th1) cytokines predominate early in TAO, whereas Th2 cytokines are more abundant later. It is currently unknown whether this transition might promote changes in tissue reactivity associated with disease progression. We report here that interferon-gamma and IL-4, representative of these respective classes of cytokines, attenuate IL-1beta-provoked PGE2 production. This down-regulation is mediated by blocking the induction of prostaglandin endoperoxide H synthase-2 (PGHS-2), the inflammatory cyclooxygenase. The mechanism involves blockade by IL-4 and interferon-gamma of the IL-1beta-dependent activation of PGHS-2 gene promoter activity. In addition, interferon gamma inhibits IL-1beta-provoked PGHS-2 mRNA stability. The actions of interferon-gamma and IL-4 are mediated through the Janus kinase 2/signal transducer and activator of transcription signaling pathway and could be abolished by treating with AG490, a specific inhibitor of Janus kinase 2. In contrast, the up-regulation of hyaluronan synthesis by IL-1beta is enhanced by either IL-4 or interferon-gamma. The latter two cytokines enhance the induction by IL-1beta of hyaluronan synthase-2 expression. These unexpected findings indicate that the Th1-->Th2 cytokine transition exerts equivalent influence on PGE2 and hyaluronan production as TAO progresses from early to late stage.

IL-1β Induces IL-6 Expression in Human Orbital Fibroblasts: Identification of an Anatomic-Site Specific Phenotypic Attribute Relevant to Thyroid-Associated Ophthalmopathy

Human orbital fibroblasts exhibit a unique inflammatory phenotype. In the present study, we report that these fibroblasts, when treated with IL-1beta, express high levels of IL-6, a cytokine involved in B cell activation and the regulation of adipocyte metabolism. The magnitude of this induction is considerably greater than that in dermal fibroblasts and involves up-regulation of IL-6 mRNA levels. IL-1beta activates both p38 and ERK 1/2 components of the MAPK pathways. Disrupting these could attenuate the IL-6 induction. The up-regulation involves enhanced IL-6 gene promoter activity and retardation of IL-6 mRNA decay by IL-1beta. Dexamethasone completely blocked the effect of IL-1beta on IL-6 expression. Orbital fibroblasts also express higher levels of IL-6R than do skin-derived cells. When treated with rIL-6 (10 ng/ml), STAT3 is transiently phosphorylated. Thus, the exaggerated capacity of orbital fibroblasts to express high levels of both IL-6 and its receptor in an anatomic site-selective manner could represent an important basis for immune responses localized to the orbit in Graves' disease.

Measuring disease activity to predict therapeutic outcome in Graves' ophthalmopathy

OBJECTIVE

The concept of disease activity in Graves' ophthalmopathy (GO) might explain why as many as one-third of patients do not respond to immunosuppressive treatment, because only patients in the active stage of disease are expected to respond. The hypothesis was adopted that a parameter used to measure disease activity should be able to predict a response to immunosuppressive treatment. The aim of this study was to develop a multivariate prediction model in which all previous tested activity parameters are integrated.

DESIGN AND PATIENTS

We included 66 consecutive patients with untreated moderately severe GO who had been euthyroid for at least 2 months. All patients were treated with radiotherapy. Measurements Treatment efficacy after 6 months follow-up was used as the primary outcome measure. Disease severity and 15 different disease activity parameters were assessed before treatment. Univariate and multivariate logistic regression models were used to predict response (model 1) or no change (model 2).

RESULTS

In multivariate analyses, we found that duration of GO, soft tissue involvement, elevation, soluble interleukin-2 receptor (sIL-2R), soluble CD30 (sCD30), eye muscle reflectivity and octreotide uptake ratio were significant predictors of a response to radiotherapy. Gender, duration of GO, soft tissue involvement, eye muscle reflectivity, IL-6 and urinary glycosaminoglycan (GAG) excretion were significant predictors of no change upon radiotherapy. Prognostic score charts were developed for use in clinical practice to calculate the probability of response (model 1) and the probability of no change (model 2) for each new patient. Finally we used a combination of both models to define a recommended treatment modality for each individual patient, based on both the predicted probabilities of response and no change. We were able to identify the correct treatment (based on a comparison with the observed response) in 89% of the patients.

CONCLUSIONS

Although we strongly recommend that our results should be confirmed in other studies, our findings are the first evidence for the idea that disease (in)activity should determine which kind of treatment should be used.

Association of tumor necrosis factor and human leukocyte antigen DRB1 alleles with Graves' ophthalmopathy

Tumor necrosis factor (TNF)-alpha plays a central role in the development of ophthalmopathy in patients with Graves' disease (GD). The aim of this study was to investigate the association of TNF promoter polymorphisms at positions -1031 (T-1031C), -863 (C-863A), -857 (C-857T), -308 (G-308A), and -238 (G-238A) with Graves' ophthalmopathy (GO). We studied the distribution of TNF and human leukocyte antigen (HLA) DRB1 alleles in 228 Polish white patients with GD, 106 of whom had ophthalmopathy (NOSPECS class > or = III) and 248 healthy subjects. TNF -308A and HLA-DRB1*03 alleles were significantly increased in patients with GD compared with healthy subjects. Stratification analysis revealed no independent association of -308A with GD when the DRB1*03 status was considered. Subdividing GD according to eye involvement revealed that the distribution of TNF promoter haplotypes differed significantly in patients with or without ophthalmopathy. The haplotype containing the -238A allele was absent in GO. The association of G-238A with GO was independent of DRB1 alleles. These results indicate that TNF G-308A is associated with susceptibility to GD (however, this association is not independent of HLA-DRB1*03) and that TNF G-238A is associated with the development of ophthalmopathy, suggesting that G-238A or a gene in linkage disequilibrium may be disease modifying in GD.

New understanding of the role of cytokines in the pathogenesis of Graves' ophthalmopathy

Cytokines play a key role in the development of Graves' ophthalmopathy (GO). These molecules are produced in the orbit of GO patients by infiltrating inflammatory cells as well as orbital fibroblasts. Locally produced cytokines stimulate fibroblast proliferation and their production of glycosaminoglycans, which result in accumulation of extracellular matrix and oedema with consequent proptosis. In addition to these direct effects, cytokines can modulate the immune reaction in GO by increasing major histocompatibility complex (MHC) class II, adhesion molecules, CD40, prostaglandin and heat shock protein expression in the orbit, thereby having a role in localising and augmenting the inflammatory response.

Th1 and Th2 serum cytokine profiles characterize patients with Hashimoto's thyroiditis (Th1) and Graves' disease (Th2)

OBJECTIVES

The aim of this study was to document the pattern of immune response, assessed by the measurement of both Th1 and Th2 serum cytokines, in patients suffering from autoimmune thyroid disease and toxic nodular goiter.

METHODS

Both Th1 and Th2 serum cytokine levels were assayed in patients suffering from Graves' disease (GD, n = 25), Hashimoto's thyroiditis (HT, n = 21), and toxic nodular goiter (TNG, n = 7) and compared with corresponding levels of 25 healthy controls. Serum concentrations of IL-2, IL-1 beta, INF-gamma, TNF-alpha, IL-12, IL-15, IL-10, IL-18, IL-4 and IL-5 were assayed in fasting serum samples.

RESULTS

It was found that patients with HT had higher IL-2 serum levels (12.16 +/- 0.66 pg/ml) compared to patients with TNG (9.25 +/- 0.84 pg/ml), GD (7.86 +/- 0.30 pg/ml) and controls (7.36 +/- 0.45 pg/ml; p = 0.0001), higher INF-gamma levels (7.60 +/- 0.33 pg/ml) compared to patients with TNG (5.77 +/- 0.55 pg/ml), GD (5.74 +/- 0.24 pg/ml) and controls (5.09 +/- 0.27 pg/ml; p = 0.0009), higher IL-12 levels (3.57 +/- 0.19 pg/ml) compared to patients with TNG (2.57 +/- 0.21 pg/ml), GD (2.48 +/- 0.13 pg/ml) and controls (2.59 +/- 0.23 pg/ml; p = 0.004), and higher IL-18 levels (27.52 +/- 1.75 pg/ml) compared to patients with TNG (18.71 +/- 2.24 pg/ml), GD (15.44 +/- 1.39 pg/ml) and controls (15.16 +/- 1.62 pg/ml; p = 0.0002). In contrast, patients with GD had higher serum levels of IL-4 (4.11 +/- 0.33 pg/ml) compared to patients with HT (3.0 +/- 0.16; p = 0.02) and higher IL-5 levels (4.22 +/- 0.30 pg/ml) compared to patients with TNG (3.21 +/- 0.58 pg/ml), HT (2.75 +/- 0.16 pg/ml) and controls (2.0 +/- 0.19 pg/ml; p = 0.0001). Patients had lower IL-1 beta serum levels (TNG 2.45 +/- 0.20, HT 2.52 +/- 0.14, GD 2.68 +/- 0.12 pg/ml) compared to controls (3.6 +/- 0.20 pg/ml; p = 0.008).

CONCLUSIONS

The above findings suggest that a Th1 pattern of immune response characteristic of cellular immunity is dominant in HT, whereas the predominance of Th2 cytokines in GD indicates a humoral pattern of immune reaction.

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.

Relationships existing between the serum cytokine levels and bone mineral density in women in the premenopausal period affected by Graves' disease with subclinical hyperthyroidism

We examined the relationships existing between serum cytokine levels and bone mineral density (BMD) in women of premenopausal age affected by Graves' disease with subclinical hyperthyroidism. The study population consisted of 21 women with untreated hyperthyroid Graves' disease (group H) (age, 36 +/- 2 years), eight women with untreated subclinical hyperthyroid status (group SH) (age, 33 +/- 5 years) and 10 healthy women (group N) (age, 35 +/- 3 years). The following measurements were made in all patients: free T4 (fT4), free T3 (fT3), thyroid stimulating hormone (TSH), TSH receptor antibody (TRab), anti-thyroid peroxidase antibody (anti-TPO), anti-thyroglobulin antibody (anti-Tg), interleukin-2 receptor (IL-2r), interleukin-4 (IL-4), interleukin-8 (IL-8) and interleukin-13 (IL-13). IL-2r and IL-8 levels significantly increased in group H compared with group SH (p < 0.01 and p = 0.05, respectively) and group N (p < 0.001 and p = 0.02, respectively). IL-4 and IL-13 levels tended to be lower in groups H and SH compared with group N, although this difference did not reach statistical significance. Bone mineral density was significantly reduced in only two areas of the femur in group H compared with group N. There was no difference in BMD between groups SH and N. There was no correlation between thyroid hormones, serum cytokine levels and BMD in either group. In conclusion, these results suggest that there were no relationships existing between the serum level of these cytokines and BMD in women of premenopausal age affected by Graves' disease with subclinical hyperthyroidism.

Relative overexpression of macrophage-derived cytokines in orbital adipose tissue from patients with graves' ophthalmopathy

Graves' ophthalmopathy (GO) is an autoimmune disorder involving the adipose and connective tissues of the orbit. The study of cytokines present in these tissues may reveal the nature of the cells and immune responses involved in GO pathogenesis. In the current study, we performed relative quantification of the expression of cytokine genes in orbital adipose tissue from patients with GO (n = 6) and normal individuals (n = 2). Real-time RT-PCR was performed using fluorescent probes and primers for cytokines including IL-1 beta, IL-2, IL-4, IL-5, IL-8, IL-10, IFN-gamma, and TNF-alpha. Results showed IL-1 beta to be the gene having the greatest fold expression increase over normal in four of six patients. TNF-alpha was increased in all six GO patients. In addition, IL-8, IL-10, and IFN-gamma were increased in five of six GO patients. We found no evidence of either IL-4 or IL-5 expression in any of the GO or normal samples. The increased expression of the macrophage-derived cytokines IL-1 beta, TNF-alpha, and IL-10 suggests the presence of macrophage activation and ongoing antigen presentation within the orbit in GO. In addition, the overexpression of IFN-gamma, without evidence of IL-4 or IL-5 expression, supports the concept that cell-mediated, rather than humoral, immunity plays the predominant role in pathogenesis of this disorder.

Serum concentrations of tumour necrosis factor-alpha (TNF-alpha) and soluble TNF-alpha receptor p55 in patients with hypothyroidism and hyperthyroidism before and after normalization of thyroid function

BACKGROUND

Tumour necrosis factor-alpha (TNF-alpha) is a cytokine with numerous immunological and metabolic activities. Receptors for TNF-alpha have been demonstrated in thyroid follicular cells and TNF-alpha and its receptors have been implicated in the cytotoxic mechanisms that characterize the thyroid destruction in autoimmune thyroid disease. In patients with Graves' disease, serum levels of TNF-alpha have been reported to be elevated and administration of TNF-alpha to humans has been shown to induce hormonal alterations resembling those seen in the nonthyroidal illness syndrome.

OBJECTIVE

To evaluate serum concentrations of TNF-alpha and the soluble receptor for TNF-alpha (sTNFR-I) in a group of patients with thyroid dysfunction before and after normalization of thyroid function with appropriate therapy.

DESIGN

We studied 20 patients with hypothyroidism (18 women and 2 men, mean age +/- SD, 48.8 +/- 16.1 years) and 20 patients with hyperthyroidism (14 women and 6 men, age 44.6 +/- 15.9 years). Patients were assessed at the time of diagnosis and again after normalization of thyroid function tests with appropriate therapy. A group of 20 healthy subjects (15 women and 5 men, age 44.9 +/- 15.1 years) were also studied as a control group.

SETTING

All subjects were ambulatory and were studied as outpatients during visits to the endocrinology clinic.

MEASUREMENTS

Serum concentrations of free T4 (FT4), total T3, TSH, TNF-alpha and sTNFR-I were measured in all subjects. TNF-alpha and sTNFR-I were measured using a quantitative enzyme immunoassay.

RESULTS

In patients with hypothyroidism serum concentrations of TNF-alpha (3.17 +/- 1.18 pg/ml) and sTNFR-I (1273 +/- 364 pg/ml) were significantly higher than those found in controls (2.42 +/- 0.76 pg/ml, P < 0.05, and 971 +/- 235 pg/ml, P < 0.01, respectively). Normalization of thyroid function with l-thyroxine therapy did not significantly modify TNF-alpha or sTNFR-I levels. There were no differences in pre- and post-therapy values of TNF-alpha and sTNFR-I in patients with autoimmune (n = 14) or nonautoimmune (n = 6) hypothyroidism. Before therapy, patients with hyperthyroidism showed elevated serum concentrations of TNF-alpha (3.36 +/- 1.21 pg/ml; P < 0.01) and sTNFR-I (2274 +/- 579 pg/ml; P < 0.001) in relation to the control group. Treatment of hyperthyroidism was accompanied by a normalization of TNF-alpha levels (2.46 +/- 0.89 pg/ml; P < 0.001) and by a significant decrease in sTNFR-I concentrations (1369 +/- 475 pg/ml; P < 0.001). Post-therapy levels of TNF-alpha and sTNFR-I showed a significant correlation with loss of weight (r = 0.674, P < 0.01, and r = 0.629, P < 0.01, respectively) in hypothyroid patients. No correlation between these parameters was found in the group of patients with hyperthyroidism.

CONCLUSIONS

In summary, these results confirm the relevance of activation of the TNF-alpha system in patients with thyroid dysfunction, as high plasma concentrations of TNF-alpha and sTNFR-I have been demonstrated in patients with hypothyroidism or hyperthyroidism. Treatment of hyperthyroidism is accompanied by a significant reduction in the previously elevated concentrations of both TNF-alpha and sTNFR-I. However, these changes are not seen when normalizing thyroid function in patients with hypothyroidism.

Role of cytokines in the pathogenesis of thyroid-associated ophthalmopathy

Thyroid-associated ophthalmopathy (TAO) is generally considered to be an autoimmune disorder associated with Graves' disease. However, the nature of autoantigen or mechanism of the development of ophthalmopathy remains unclear. In the present review we focus the accumulating evidence on roles of cytokines in the orbital tissues from patients with TAO and animal models. From the analysis of T-cell clones, T helper 1 (T(H)1)-like clones were predominant in cultures from patients with recent onset hyperthyroidism and T(H)2-like clones were predominant in culture form patients with more remote onset hyperthyroidism. T(H)1-like cytokine profiles are predominant in eye muscle tissue and related to the eye muscle enlargement, while T(H)2-like cytokine profiles are predominant in orbital fat tissue from patients with TAO and negatively related to orbital volume. Therefore, T(H)1-like cytokines, proinflammatory cytokines, may play a role on the development of eye muscle component of TAO in the acute stage. T(H)2-like cytokines, anti-inflammatory cytokines, may play protective role in the chronic stage of TAO. The studies using animal models suggest the genetic background is involved in the pathogenesis of TAO. The studies on polymorphism of the cytokine genes support the proinflammatory role of T(H)1-like cytokines and protective role of T(H)2-like cytokines.