Dominant infiltration of T(H)1-type CD4+ T cells at the retrobulbar space of patients with thyroid-associated ophthalmopathy

Efficiency and Safety of Tocilizumab for the Treatment of Thyroid Eye Disease: A Systematic Review

PURPOSE

To review existing literature concerning the effectiveness and safety of tocilizumab (TCZ) for managing thyroid eye disease.

METHODS

A systematic search was conducted across the PubMed and Embase databases to identify studies on TCZ therapy, from inception to May 2023. The search included the keywords "Graves orbitopathy," "thyroid ophthalmopathy," "thyroid eye disease," "thyroid-associated orbitopathy," "thyroid-associated ophthalmopathy," "Graves ophthalmopathy," "endocrine ophthalmopathy," and "Tocilizumab." Only articles written in English, Spanish, or French were considered.

RESULTS

Among the 1,013 articles initially screened, a total of 29 fulfilled the eligibility criteria and were selected. Most studies were case reports or case series, and only one randomized clinical trial was found. TCZ has been used mainly in glucocorticoid-resistant or relapsing cases, with a dosage ranging from 4 or 8 mg/kg every 4 weeks when intravenous or a weekly subcutaneous dose of 162 mg. Treatment duration is usually adjusted to the clinical response. TCZ is mostly effective in reducing inflammatory signs during the active phase of thyroid eye disease, with an improvement of at least 3 points in clinical activity score and an overall relapsing rate of 8.2%. Numerous studies have shown marked reductions in proptosis; although the only available randomized controlled trial reported a nonstatistically significant improvement 6 months after treatment, a recent meta-analysis indicated that TCZ seems to be the most effective treatment for reducing proptosis. No severe side effects related to intravenous or subcutaneous TCZ administration were reported.

DISCUSSION

Despite these promising findings, randomized clinical trials to directly compare the efficacy and safety of TCZ and other currently available therapeutic options are needed.

Roles of four targets in the pathogenesis of graves' orbitopathy

Graves' orbitopathy (GO) is an autoimmune disease that involves complex immune systems. The mainstays of clinical management for this disease are surgery, targeted drugs therapy, and no-targeted drugs drug therapy. targeted drugs can improve therapeutic efficacy and enhance the quality of life for GO patients. However, as a second-line treatment for GO, targeted drugs such as tocilizumab and rituximab have very limited therapeutic effects and may be accompanied by side effects. The introduction of Teprotumumab, which targets IGF-IR, has made significant progress in the clinical management of GO. The pathophysiology of GO still remains uncertain as it involves a variety of immune cells and fibroblast interactions as well as immune responses to relevant disease targets of action. Therfore, learning more about immune response feedback pathways and potential targets of action will assist in the treatment of GO. In this discussion, we explore the pathogenesis of GO and relevant work, and highlight four potential targets for GO: Interleukin-23 receptor (IL-23 R), Leptin receptor (LepR), Orbital fibroblast activating factors, and Plasminogen activator inhibitor-1 (PAI-1). A deeper understanding of the pathogenesis of GO and the role of potential target signaling pathways is crucial for effective treatment of this disease.

m6A methyltransferase METTL3 participated in sympathetic neural remodeling post-MI via the TRAF6/NF-κB pathway and ROS production

OBJECTIVE

Sudden cardiac death caused by ventricular arrhythmias (VAs) is the main cause of high mortality in patients with myocardial infarction (MI). Sympathetic neural remodeling caused by inflammation after MI is closely associated with the occurrence of VAs. METTL3, the earliest identified m⁶A methyltransferase, is critical in mediating inflammatory responses. Our aim was to investigate whether the m⁶A methyltransferase METTL3 was involved in sympathetic remodeling post-MI and its specific mechanism.

METHODS AND RESULTS

A rat MI model was established via left coronary artery ligation. The expression of METTL3, TRAF6, NOX2, and NF-κB increased at 3 days and remained elevated at 7 days after MI, as determined via Western blotting. METTL3 was primarily present in macrophages, as determined via immunofluorescence. Intramyocardial injection of lentivirus carrying METTL3-shRNA inhibited METTL3 expression in vivo. Methylated immunoprecipitation-qPCR determined the METTL3 knockdown inhibited the m⁶A level of TRAF6 mRNA 3'-UTR. The co-immunoprecipitation experiment proved that METTL3 combines with TRAF6. Western blotting showed that silencing METTL3 inhibited TRAF6 level, NF-κB activation, and ROS production; decreased cytokine release (TNF-α and IL-1β); and downregulated nerve growth factor expression. Finally, METTL3 knockdown reduced sympathetic remodeling after MI, as determined via immunofluorescence assays of tyrosine hydroxylase and growth-associated protein 43. Programmed electrical stimulation, renal sympathetic nerve activity recording, and haemodynamic measurements showed that METTL3 inhibition decreased sympathetic activity and improved cardiac function.

CONCLUSIONS

Downregulation of METTL3 expression attenuated the excessive sympathetic neural remodeling induced by MI, further reducing the incidence of VAs and improving cardiac function. This was partly associated with the inhibition of the TRAF6/NF-κB pathway and ROS production.

A novel CD4+ CTL subtype characterized by chemotaxis and inflammation is involved in the pathogenesis of Graves' orbitopathy

Graves' orbitopathy (GO), the most severe manifestation of Graves' hyperthyroidism (GH), is an autoimmune-mediated inflammatory disorder, and treatments often exhibit a low efficacy. CD4+ T cells have been reported to play vital roles in GO progression. To explore the pathogenic CD4+ T cell types that drive GO progression, we applied single-cell RNA sequencing (scRNA-Seq), T cell receptor sequencing (TCR-Seq), flow cytometry, immunofluorescence and mixed lymphocyte reaction (MLR) assays to evaluate CD4+ T cells from GO and GH patients. scRNA-Seq revealed the novel GO-specific cell type CD4+ cytotoxic T lymphocytes (CTLs), which are characterized by chemotactic and inflammatory features. The clonal expansion of this CD4+ CTL population, as demonstrated by TCR-Seq, along with their strong cytotoxic response to autoantigens, localization in orbital sites, and potential relationship with disease relapse provide strong evidence for the pathogenic roles of GZMB and IFN-γ-secreting CD4+ CTLs in GO. Therefore, cytotoxic pathways may become potential therapeutic targets for GO.

Glycogen Synthase Kinase-3β Mediates Proinflammatory Cytokine Secretion and Adipogenesis in Orbital Fibroblasts from Patients with Graves' Orbitopathy

Purpose

We sought to determine the role of glycogen synthase kinase-3β (GSK-3β) in the pathogenesis of Graves’ orbitopathy(GO).

Methods

Expression of the GSK-3β gene in whole orbital tissue explants was compared between GO and non-GO donors using quantitative real-time PCR (RT-PCR). The expression of proinflammatory molecules in the presence of the GSK-3β inhibitor CHIR 99021 was analyzed using RT-PCR, western blot, and ELISA. Adipogenic differentiation was identified using Oil Red O staining, and the levels of peroxisome proliferator activator gamma (PPARγ) and CCAAT-enhancer-binding proteins (C/EBPs) α and β were determined by western blot.

Results

The expression of GSK-3β was significantly higher in GO tissues than in control tissues. The addition of CHIR 99021 led to a decrease in the active form of the kinase in which the Y216 residue is phosphorylated. When GO and non-GO fibroblasts were stimulated with IL-1β or TNF-α, IL-6, IL-8, intercellular adhesion molecule-1 (ICAM-1), cyclooxygenase-1 (COX-1), and monocyte chemoattractant protein 1 (MCP-1) showed increased production, which was blunted when CHIR 99021 was added. The activation of Akt, PI3K, nuclear factor (NF)-κB, Erk, Jnk, and p38 kinase by IL-1β and TNF-α was diminished with CHIR 99021 in GO cells. A decrease in lipid droplets and expression of PPARγ and c/EBPα and -β was noted in fibroblasts treated with CHIR 99021 during adipocyte differentiation. The inhibition of Wnt and β-catenin in adipogenesis was reversed by CHIR 99021.

Conclusions

GSK-3β plays a significant role in GO pathogenesis. The inhibition of the kinase attenuated the proinflammatory cytokines production and fibroblast differentiation into adipocytes. GSK-3β may be a potential target for anti-inflammatory and anti-adipogenic treatment of GO.

Mechanisms That Underly T Cell Immunity in Graves' Orbitopathy

Graves' orbitopathy (GO), also known as thyroid-associated ophthalmopathy, is the most common ocular abnormality of Graves' disease. It is a disfiguring, invalidating, and potentially blinding orbital disease mediated by an interlocking and complicated immune network. Self-reactive T cells directly against thyroid-stimulating hormone receptor-bearing orbital fibroblasts contribute to autoimmune inflammation and tissue remodeling in GO orbital connective tissues. To date, T helper (Th) 1 (cytotoxic leaning) and Th2 (antibody leaning) cell subsets and an emerging role of Th17 (fibrotic leaning) cells have been implicated in GO pathogenesis. The potential feedback loops between orbital native residential CD34^- fibroblasts, CD34⁺ infiltrating fibrocytes, and effector T cells may affect the T cell subset bias and the skewed pattern of cytokine production in the orbit, thereby determining the outcomes of GO autoimmune reactions. Characterization of the T cell subsets that drive GO and the cytokines they express may significantly advance our understanding of orbital autoimmunity and the development of promising therapeutic strategies against pathological T cells.

Comparison of two regimens for patients with thyroid-associated ophthalmopathy receiving intravenous methyl prednisolone: A single center prospective randomized trial

Intravenous (i.v.) glucocorticoid is recommended for active moderate-to-severe thyroid-associated ophthalmopathy (TAO). However, the details of the treatment schedule are still debatable. The present prospective randomized trial was performed to compare clinical outcomes and serum cytokines between the two regimens. A cohort of 90 patients with active moderate-to-severe TAO was randomized to receive i.v. methyl prednisolone on a weekly protocol or daily scheme. The response rate was evaluated at the 12-week follow-up visit. Serum interleukin (IL)-2, IL-6 and IL-17 levels were measured in 160 patients with TAO, 60 patients with isolated Graves' disease (GD) and 60 normal control (NC) at baseline, as well as patients with active moderate-to-severe TAO at the 12^th week after treatment. The daily scheme had a higher response rate than the weekly protocol without a significant difference (77.8 vs. 63.6%, P>0.05). No major adverse events were recorded under either regimen. Overall, minor events were more common on the daily scheme (11.36 vs. 4.35%, P<0.05)than on the weekly protocol, whereas the deterioration of eye symptoms (two patients) was only reported on the weekly protocol. At baseline, the IL-17 level in the TAO group was higher than that in the isolated GD and NC groups (P<0.05). In addition, the IL-17 level in the active TAO group was higher than that in the inactive TAO group (P<0.05). Furthermore, the IL-17 level had significantly decreased under the two regimens at the 12-week visit (P<0.05). In conclusion, for patients with active moderate-to-severe TAO, daily i.v. glucocorticoid therapy has a relative higher response rate than the weekly protocol with a few more minor adverse events. These two regimens have their own merits with regard to adverse effects. IL-17 has the potential to be a biomarker for evaluating TAO activity and treatment effects.

The critical role of m6A methylation in the pathogenesis of Graves' ophthalmopathy

PURPOSE

To investigate the role of N6-methyladenosine (m⁶A) RNA modification in the pathogenesis of Graves' ophthalmopathy (GO).

METHODS

Surgically excised extraocular muscles from 7 patients with GO and 5 subjects without GO were used. The global m⁶A levels in the specimens were determined using an m⁶A RNA methylation quantification kit. RNA sequencing (RNA-seq) was used to analyze the molecules involved in the regulation of m⁶A RNA methylation and the differential expression of mRNAs between the two groups (4 eyes, respectively). The expression of m⁶A RNA modification genes was evaluated by real-time PCR. The functional implications of the gene alterations between the GO and control specimens were determined by Gene Ontology analysis.

RESULTS

The m⁶A level was significantly increased in the specimens of GO patients compared to the control specimens (P < 0.05). The expression of m⁶A methylation regulators, such as WT1 associated protein (WTAP), alkylation repair homolog protein 5 (ALKBH5), E74 like ETS transcription factor 3 (ELF3), YTH N6-methyladenosine RNA binding protein 2 (YTHDF2), YTHDF3 and YTH domain containing 2 (YTHDC2), was significantly upregulated (P < 0.05). Gene Ontology enrichment analysis showed that the most highly upregulated genes and biological pathways were related to the immune response and inflammatory processes such as lymphocyte activation, leukocyte differentiation, cytokine production and cytokine-mediated signaling pathways.

CONCLUSIONS

Our results suggest that m⁶A methylation may play a critical role in the pathogenesis of GO and that targeting genes that regulate m⁶A methylation may provide a new therapeutic approach for GO.

Efficacy of orbital radiotherapy in moderate-to-severe active graves' orbitopathy including long-lasting disease: a retrospective analysis

Background

We aimed to explore the efficacy of orbital radiotherapy (RT) in patients with moderate-to-severe active Graves’ orbitopathy (GO), including long-lasting disease, and to determine the predictive factors associated with treatment response.

Methods

This was a retrospective study of 62 moderate-to-severe active GO patients treated with RT. Demographic data and ophthalmic findings prior to RT and at 3 and 6 months afterward were analyzed. Computed tomography was performed before and after RT to compare orbital volume change. We used logistic regression to determine the predictive factors for treatment response. Subjects were divided into early- and late-active phase groups based on GO duration of 24 months and treatment outcomes were compared with each other to observe the effects of RT timing on treatment response.

Results

Forty (64.5%) and forty-six (74.1%) patients experienced improvements in GO at 3 and 6 months after radiotherapy, respectively. Ocular parameters such as clinical activity score (CAS), proptosis, extraocular muscle (EOM) limitation, and compressive optic neuropathy (CON) were improved by RT. Volumes of EOM significantly decreased after RT. The enlargement of EOMs and EOM limitation were predictive factors for a good response to RT. At 6 months after RT, 22 (68.8%) patients of late-active phase group exhibited improvement in GO, which is comparable to the number of 24 (80.0%) patients of early-active phase group. In the late-active phase group, CAS, diplopia, and visual acuity were improved significantly, but there was no change in EOM limitation.

Conclusions

In moderate-to-severe active GO patients, orbital RT may help improve high CAS, proptosis, EOM limitation, and CON. The orbital RT in long-lasting active GO patients may be considered as treatments for the relief of symptoms including high CAS and poor visual acuity.

Immunological Features of Paranasal Sinus Mucosa in Patients with Graves' Orbitopathy

BACKGROUND

Previous studies showed that patients with Graves' orbitopathy (GO) had concomitant mucosal abnormality within the paranasal sinuses. It remains unknown whether the immunological reactions in sinus mucosa affect the orbit inflammation in GO.

METHODS

Patients with GO underwent sinus computed tomography (CT) scans for sinus mucosal disease by two independent reviewers using the Lund-MacKay systems. Ethmoid mucosal samples were collected during orbital decompression surgeries for patients with GO and correction surgeries for patients with old orbital fractures as controls. Histological analysis and immunofluorescence were performed in all sinus mucosa tissues. Flow cytometry analysis was used to examine the immunological features of sinus mucosa in both GO and control groups.

RESULTS

Immunohistochemistry showed that the paranasal sinus mucosa of patients with GO grew swelling, with goblet cell and small vessel proliferation, endothelial cell swelling, and inflammatory cell infiltration. The number of T helper (Th)1, Th17, and gamma-delta T cells in nasal sinus mucosa of patients with GO increased significantly compared with those from controls. Further, the proportion of Th1 cells was significantly correlated with clinical activity score. In addition, there was a decreased number of regulatory T cells in patients with GO. The number of Th2 cells showed no significant difference between the two groups. Finally, the proportion of interleukin-22-producing cell subsets in gamma-delta T cells of patients with GO was significantly increased compared with those from controls.

CONCLUSIONS

Our observations illustrated a potential pathogenic role of mucosal-infiltrating T cells, which may have the possibility to aggravate inflammatory responses in GO.

Efficacy and safety of tripterygium glycosides for Graves ophthalmopathy: A systematic review and meta-analysis

BACKGROUND

Graves ophthalmopathy (GO) is one of the remaining enigmas in thyroidology. Glucocorticoids (GCs) are strongly recommended but their effects are not completely satisfactory and adverse reactions can occur. Tripterygium glycosides (TG) is a promising component extracted from Tripterygium wilfordii Hook F (TwHF), and numerous patients with GO have benefited from it. However, its practical application value is still unclear. The aim of this systematic review and meta-analysis was to investigate the efficacy and safety of TG for patients with GO.

METHODS

By retrieving the PubMed, Embase, the Cochrane Library, CNKI, VIP, CBM, and WanFang Databases, the open published randomized controlled trials (RCTs) related to TG in the treatment of GO were collected. And inclusion and exclusion criteria were established. The Cochrane bias risk assessment tool conducts the evaluation of included studies, and meta-analysis was performed using Revman 5.3 software.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42019131915.

RESULTS

A total of 19 trials (involving 1517 GO patients) were included in this review with generally acceptable validity of included RCTs. TG therapy brought about a significantly higher efficacy rate compared with non-TG treatments (RR: 1.40; 95% CI: 1.31-1.49). Subgroup meta-analysis showed that TG with or without immunosuppressive therapies were all better than controls: with GC (RR: 1.36; 95% CI: 1.27-1.46), with multiple intensification of immunosuppressive therapies (RR: 1.91; 95% CI: 1.37-2.67), with no immunosuppressive therapies (RR: 1.39; 95% CI:1.21-1.59); the dosage of TG for 15-60 mg/d (RR: 1.41; 95% CI: 1.30-1.53) were better compared with for ≥90 mg/d (RR: 1.47; 95% CI: 1.29-1.68); the course of treatment for ≤3 months (RR: 1.43; 95% CI: 1.33-1.52) was better than controls, but when >3 months (RR: 1.15; 95% CI: 0.94-1.41) there was no significant differences. After treatment, the degree of exophthalmus (SMD: -2.55; 95% CI: -2.93 to 2.17), the recurrence rate of 1 year (RR: 0.45; 95% CI: 0.27-0.74), and adverse reactions rate (RR: 0.32; 95% CI: 0.20-0.53) were all lower, while the CAS was no obvious gap in 2 groups (SMD: 0.08; 95% CI: -0.60 to 0.75).

CONCLUSIONS

This review found that TG has some advantages in treating GO, especially in improving clinical efficacy and reducing adverse reactions. Nevertheless, large sample, multi-center, reasonable design, and high quality clinical studies are still needed for further verification.

Decreased Expression of TIM-3 on Th17 Cells Associated with Ophthalmopathy in Patients with Graves' Disease

Purpose:

Thyroid-associated Ophthalmopathy (TAO) is one of the most common orbital immunological diseases in adults. CD4+ helper T (Th) cells play important roles in the pathogenesis of TAO. But the mechanisms regulating CD4+ T cell activity is unclear. This study examines T cell immunoglobulin domain and mucin domain 3 (TIM-3) expression in helper T cell type 1 (Th1), Th17, and regulatory T cells in sufferers of TAO.

Methods:

Participants were divided into 3 groups: patients with TAO, patients with Graves’ disease but without orbitopathy (GD), and healthy control patients (HC). Peripheral blood samples were collected for each patient in the designated group. Flow cytometry methods assessed the frequency of Th1 (CD4+IFN-γ+), Th17 (CD4+IL-17+), regulatory T cells (CD4+CD25hiCD127lo), and TIM-3 protein expression. Mean fluorescence intensity (MFI) measured the magnitude of TIM-3 expression and the percentage of TIM-3+ cells for each patient.

Results:

Compared to the GD group, TAO patients possessed higher frequencies of Th1 and Th17 cells in peripheral blood samples. The percentage of TIM-3+ Th1 and Th17 cells was significantly lower in the TAO patients than the GD group. Across all patients sampled, TIM-3+ cell percentage negatively correlated with Th1 cell frequency. Th1 and Th17 cells exhibited significantly decreased expression of TIM-3 in TAO patients compared to healthy controls. Regulatory T cells showed little TIM-3 expression and we observed no significant differences in frequency between groups.

Conclusion:

These results suggest a role for TIM-3 in the regulation of Th1 and Th17 cells and the pathogenesis of Graves’ ophthalmopathy.

Improvement of the MRI and clinical features of Asian Graves' ophthalmopathy by radiation therapy with steroids

PURPOSE

To evaluate the effectiveness of radiation therapy and steroids for Asian patients with Graves' ophthalmopathy using the clinical activity score (CAS), and changes in external ocular muscles and eye proptosis determined by magnetic resonance imaging (MRI).

MATERIALS AND METHODS

We retrospectively reviewed 48 patients who received combined orbital radiation and systemic glucocorticoids in our hospital. MRI was performed both before and 1 month after treatment in all patients. We calculated the areas of five extraocular muscles and the degree of proptosis on transverse sections, and we evaluated the activity of the disease using CAS before and 1 month after treatment and toxicity.

RESULTS

The areas of external ocular muscles, the length of eye prominence and CAS were significantly improved by the combination of orbital radiation and steroids. The change in the area of the medial rectus muscle had a significant correlation with the change in CAS (P < 0.05). Graves' ophthalmopathy progressed again in 4 of the 48 patients; however, there were no patients with serious side effects in a median observation period of 41.5 months.

CONCLUSION

Treatment with the combination of orbital radiation and systemic glucocorticoids is subjectively and objectively effective for Asian Graves' ophthalmopathy without severe toxicity.

Interruption of autoimmunity for thyroid eye disease: B-cell and T-cell strategy

Recent new insights into the molecular basis of thyroid eye disease have led to the use of more specific therapies such as monoclonal antibodies This review explores the traditional immunosuppressant therapy for TED, highlighting the basis for emergent recent medications, possible treatment options and, eventually possible new general recommendation for management of TED. Data has been retrieved from the literature searching on Pubmed. Steroid therapy remains the first line therapy for moderate/severe and severe vision threatening TED The use of some traditional nonspecific immunosuppressant such as mycophenolate, cyclosporine and azathioprine seems useful in combination with steroid therapy to achieve stable results in the long term; methotrexate is useful as steroid-sparing medications and in steroid resistant or intolerant patients. In recent years, many scientific reports have showed the effectiveness of biological immunosuppressive agents in the management of TED. Etanercept, adalimumab, and tocilizumab have shown to be effective in reduction of the inflammatory signs with the possible advantage to prevent relapse of the disease. Particularly Tociliuzumab seems very effective as second line therapy, after steroid failure. Teprotumumab may control the disease activity and it seems to be very effective in preventing severity disease progression. Infliximab might be useful in severe TED with optic nerve compression resistant to steroid and decompression. Indeed, the actual incidence of adverse effects is not well assessed yet, therefore the use should be limited at those cases that really need an alternative therapy to steroid, handled by an expert multidisciplinary team.

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.

Distinct inflammatory gene expression in extraocular muscle and fat from patients with Graves' orbitopathy

OBJECTIVE

This study sought to compare patients with thyroid eye disease (TED) and normal controls with respect to the expression of the NR3C1, CHUK, IKBKB, FOS, NFKB and HSD11B1 genes in orbital fat (OF) and extraocular muscle (EOM).

DESIGN AND METHODS

A prospective study design was used to evaluate 34 TED patients and 38 healthy controls. OF was harvested from 33 TED patients and 27 controls. EOM biopsies were obtained from 32 TED patients and 18 controls. Samples were examined by real-time PCR and evaluated using appropriate statistical analyses with a significance cut-off of P < 0.05.

RESULTS

NR3C1 mRNA levels were higher in TED EOM (median 213 (96-376)) than those in control EOM (78 (34-138)) (P < 0.001), and NFKB expression was elevated in TED muscle (223 (31-520)) relative to that in control muscle (8 (6-31)) (P < 0.001). HSD11B1 expression was higher in TED EOM (0.78 (0.47-2.01)) than that in control EOM (0.22 (0.09-0.51)) (P < 0.001). Levels of CHUK, IKBKB, and FOS were higher in TED EOM (115 (20-223), 111 (54-299) and 0.11 (0.03-0.19), respectively) than those in control EOM (5.8 (2-13), 21 (5-52) and 0.05 (0.001-0.03) respectively) (P < 0.001).

CONCLUSION

Tissues involved in GO exhibited different mRNA levels of NR3C1, CHUK, IKBKB, FOS, NFKB and HSD11B1. Gene expression in OF was similar for TED patients and controls. CHUK, IKBKB, FOS, NFKB, and HSD11B1 mRNA levels were higher in TED EOM than those in control EOM. NFKB was disproportionally elevated compared with NR3C1; this finding was indicative of a local proinflammatory profile.

The effect of orbital decompression surgery on interpupillary distance and angle kappa in patients with thyroid-associated orbitopathy

PURPOSE

The purpose was to investigate the effects of orbital decompression surgery on postoperative changes in interpupillary distance (IPD) and angle kappa in patients with thyroid-associated orbitopathy (TAO).

METHODS

In patients with TAO who underwent orbital decompression surgery between January 1, 2014 and February 21, 2016, we measured exopthalmometry, IPD, inner intercanthal distance (IICD) and outer intercanthal distance (OICD) using a computer software program and angle kappa with an ORB scan II. We then analyzed preoperative and 3-month postoperative exophthalmometry, IPD, IICD, OICD and angle kappa to evaluate changes in eye position or rotation of the eyeball following orbital decompression surgery.

RESULTS

Fifty-four patients (35 women and 19 men) with a mean age of 34.59 (range, 16-64 years) were enrolled in this study. After decompression surgery, the IPD was significantly decreased by 1.76 mm (preoperative, 63.14 ± 3.93 mm; postoperative, 61.38 ± 3.84 mm; P < 0.001), but angle kappa, IICD, and OICD did not vary significantly (P = 0.814, P = 0.635 and P = 0.092, respectively).

CONCLUSIONS

A significant decrease in IPD was noted after orbital decompression in patients with TAO. However, there was no significant change in angle kappa. Therefore, the mechanism of change in the IPD is not an inward rotation of the eyeball, but rather an actual dorsal shift causing a wedging of the eye position itself within the orbit.

The Effect of Systemic Steroids and Orbital Radiation for Active Graves Orbitopathy on Postdecompression Extraocular Muscle Volume

PURPOSE

To evaluate the effect of orbital radiation prior to surgery on the clinical course and extraocular muscle (EOM) radiologic volume changes after decompression in Graves orbitopathy (GO).

DESIGN

Retrospective, interventional case series.

METHODS

The medical records of patients treated with orbital decompression for GO and who underwent postoperative orbital computed tomography were reviewed. Only patients who underwent rehabilitative decompression in the inactive phase and who received systemic corticosteroids alone (ST group) or combined orbital radiation and systemic corticosteroids (SRT group) in the active inflammatory phase of the disease were selected. The main outcome measure was the comparison of preoperative and postoperative EOM volumes. Secondary outcome measures were changes in proptosis and diplopia after decompression.

RESULTS

Thirty-seven of 114 patients were selected for this study. There were no differences between the ST group (n = 22, 42 eyes) and SRT group (n = 15, 30 eyes) in terms of demographics or predecompression characteristics. After decompression surgery, the total EOM volume significantly increased by 15% in the ST group, but radiated EOMs in the SRT group did not expand, resulting in decreased induction of postoperative diplopia. The percentages of patients showing increased diplopia after decompression differed significantly between the groups (ST group, 40.9% vs SRT group, 13.3%, P = .04). However, there was no difference in exophthalmos reduction after decompression between the 2 groups.

CONCLUSIONS

Orbital radiation prior to orbital decompression can reduce both the postoperative increase in EOM volume and deterioration in diplopia.

CD40 Expression in Fibrocytes Is Induced by TSH: Potential Synergistic Immune Activation

Context

Fibrocytes appear to participate in inflammation and tissue remodeling in patients with thyroid-associated ophthalmopathy (TAO). These patients have increased frequencies of circulating TSH receptor (TSHR)- and CD40-positive fibrocytes, suggesting TSHR and CD40 may play roles in proinflammatory cytokine production, which ultimately leads to orbital inflammation and tissue remodeling.

Objective

To investigate the potential interactions between the TSHR and CD40 signaling pathways and their roles in IL-6 and TNF-α production.

Design and Outcome Measures

CD40 expression on fibrocytes was assessed using flow cytometry; IL-6 and TNF-α protein release using Luminex technology; increased IL-6 and TNF-α mRNA abundance, using real-time PCR; TSH- and CD40 ligand (CD40L)-stimulated Akt phosphorylation in fibrocytes, by western blot analysis; TSHR-CD40 protein-protein interaction, using co-immunoprecipitation, and CD40-TSHR co-localization, using immunocytochemistry.

Results

TSH enhances CD40 expression at a pre-translational level in fibrocytes. Production of IL-6 and TNF-α after costimulation with TSH and CD40L was greater than that after TSH or CD40L stimulation alone. TSH and CD40L costimulation also resulted in greater Akt phosphorylation. Akt and nuclear factor (NF)-κB inhibitors significantly reduced cytokine production after TSH and CD40L costimulation. TSHR and CD40L are colocalized on the cell surface and form a complex.

Conclusions

TSHR and CD40 in fibrocytes appear to be physically and functionally related. TSH stimulates CD40 production on the fibrocyte surface. Cytokine expression upon simultaneous stimulation of TSHR and CD40 is greater than levels achieved with TSH or CD40L alone. Increased expression of CD40 by TSH is a potential mechanism for this process.

Current perspectives on the role of orbital fibroblasts in the pathogenesis of Graves' ophthalmopathy

Graves' ophthalmopathy (GO) is an extra-thyroidal complication of Graves' disease (GD; Graves' hyperthyroidism) characterized by orbital tissue inflammation, expansion, remodeling and fibrosis. Although the initiating trigger of GO is still indistinct, excessive orbital fibroblast activity is at the heart of its pathogenesis. Orbital fibroblasts are activated by cellular interactions with immune cells and the soluble factors they secrete. Orbital fibroblasts, especially from GO patients, express the thyrotropin receptor (TSH-receptor; TSHR), and activation of the orbital fibroblast population by stimulatory autoantibodies directed against the TSHR may provide an important link between GD and GO. Furthermore, stimulatory autoantibodies directed against the insulin-like growth factor-1 receptor have been proposed to contribute to orbital fibroblast activation in GO. Activated orbital fibroblasts produce inflammatory mediators thereby contributing to the orbital inflammatory process in GO. Moreover, orbital fibroblasts exhibit robust proliferative activity and extracellular matrix (especially hyaluronan) synthesizing capacity and can differentiate into adipocytes and myofibroblasts with disease progression, thereby contributing to tissue expansion/remodeling and fibrosis in GO. Orbital fibroblasts, especially those from GO patients, exhibit a hyper-responsive phenotype when compared to fibroblasts from other anatomical regions, which may further contribute to GO pathogenesis. Fibrocytes have been identified as additional source of orbital fibroblasts in GO, where they may contribute to orbital tissue inflammation, adipogenesis and remodeling/fibrosis. This review addresses our current view on the role that orbital fibroblasts fulfill in GO pathogenesis and both established as well as less established not fully crystallized concepts that need future studies will be discussed.

Pathogenesis of thyroid eye disease: review and update on molecular mechanisms

Orbital changes in thyroid orbitopathy (TO) result from de novo adipogenesis, hyaluronan synthesis, interstitial oedema and enlargement of extraocular muscles. Cellular immunity, with predominantly CD4+ T cells expressing Th1 cytokines, and overexpression of macrophage-derived cytokines, perpetuate orbital inflammation. Orbital fibroblasts appear to be the major effector cells. Orbital fibroblasts express both thyrotropin receptor (TSHR) and insulin-like growth factor-1 receptor (IGF-1R) at higher levels than normal fibroblasts. TSHR expression increases in adipogenesis; TSHR agonism enhances hyaluronan production. IGF-1R stimulation leads to adipogenesis, hyaluronan synthesis and production of the chemokines, interleukin (IL)-16 and Regulated on Activation, Normal T Cell Expression and Secreted, which facilitate lymphocyte trafficking into the orbit. Immune activation uses a specific CD40:CD154 molecular bridge to activate orbital fibroblasts, which secrete pro-inflammatory cytokines including IL-1β, IL-1α, IL-6, IL-8, macrophage chemoattractant protein-1 and transforming growth factor-β, to perpetuate orbital inflammation. Molecular pathways including adenylyl cyclase/cyclic adenosine monophosphate, phophoinositide 3 kinase/AKT/mammalian target of rapamycin, mitogen-activated protein kinase are involved in TO. The emergence of a TO animal model and a new generation of TSHR antibody assays increasingly point towards TSHR as the primary autoantigen for extrathyroidal orbital involvement. Oxidative stress in TO resulting from imbalances of the oxidation-reduction state provides a framework of understanding for smoking prevention, achieving euthyroidism and the use of antioxidants such as selenium. Progress has been made in the understanding of the pathogenesis of TO, which should advance development of novel therapies targeting cellular immunity, specifically the CD40:CD40 ligand interaction, antibody-producing B cells, cytokines, TSHR and IGF-1R and its signalling pathways. Further studies in signalling networks and molecular triggers leading to burnout of TO will further our understanding of TO.

Effect of Orbital Decompression on Corneal Topography in Patients with Thyroid Ophthalmopathy

Objective

To evaluate changes in corneal astigmatism in patients undergoing orbital decompression surgery.

Methods

This retrospective, non randomized comparative study involved 42 eyes from 21 patients with thyroid ophthalmopathy who underwent orbital decompression surgery between September 2011 and September 2014. The 42 eyes were divided into three groups: control (9 eyes), two-wall decompression (25 eyes), and three-wall decompression (8 eyes). The control group was defined as the contralateral eyes of nine patients who underwent orbital decompression surgery in only one eye. Corneal topography (Orbscan II), Hertel exophthalmometry, and intraocular pressure were measured at 1 month before and 3 months after surgery. Corneal topographic parameters analyzed were total astigmatism (TA), steepest axis (SA), central corneal thickness (CCT), and anterior chamber depth (ACD).

Results

Exophthalmometry values and intraocular pressure decreased significantly after the decompression surgery. The change (absolute value (|x|) of the difference) in astigmatism at the 3 mm zone was significantly different between the decompression group and the controls (p = 0.025). There was also a significant change in the steepest axis at the 3 mm zone between the decompression group and the controls (p = 0.033). An analysis of relevant changes in astigmatism showed that there was a dominant tendency for incyclotorsion of the steepest axis in eyes that underwent decompression surgery. Using Astig PLOT, the mean surgically induced astigmatism (SIA) was 0.21±0.88 D with an axis of 46±22°, suggesting that decompression surgery did change the corneal shape and induced incyclotorsion of the steepest axis.

Conclusions

There was a significant change in corneal astigmatism after orbital decompression surgery and this change was sufficient to affect the optical function of the cornea. Surgeons and patients should be aware of these changes.

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.

Markers of inflammation and fibrosis in the orbital fat/connective tissue of patients with Graves' orbitopathy: clinical implications

Purpose. To assess FGF-β, TGF-β, and COX2 expression and immunocompetent cells in the orbital tissue of patients with severe and mild Graves' orbitopathy. Patients and Methods. Orbital tissue was taken from 27 patients with GO: (1) severe GO (n = 18), the mean clinical activity score (CAS) being 8.5 (SD 2.5); and (2) mild GO (n = 9), the mean CAS being 2.2 (SD 0.8), and from 10 individuals undergoing blepharoplasty. The expression of CD4+, CD8+, CD20+, and CD68 and FGF-β, TGF-β, and COX2 in the orbital tissue was evaluated by immunohistochemical methods. Results. We demonstrated predominant CD4+ T cells in severe GO. CD68 expression was observed in the fibrous connective area of mild GO and was robust in severe GO, while the prominent TGF-β expression was seen in all GO. Increased FGF-β expression was observed in the fibroblasts and adipocytes of severe GO. No expression of COX2 was found in patients with GO. Conclusions. Macrophages and CD4 T lymphocytes are both engaged in the active/severe and long stage of inflammation in the orbital tissue. FGF-β and TGF-β expression may contribute to tissue remodeling, fibrosis, and perpetuation of inflammation in the orbital tissue of GO especially in severe GO.

Cytokine profiles in clinical subtypes of ophthalmic Graves' disease

PURPOSE

To examine the association of cytokines in the two clinical subtypes of ophthalmic Graves' disease by comparing cytokine expression in the fat and ethmoid tissue of type I and type II patients.

METHODS

Patients needing orbital decompression or eyelid surgery were identified and enrolled into a prospective study. Patients were assigned to the type I or type II subclassification, based on the presence of diplopia. Orbital fat, sinus tissue or muscle removed during surgery was evaluated. The mRNA expression profiles of Th1 cytokines (TNF-alpha/beta, IFN-gamma, IL-2) and Th2 cytokines (IL-4, IL-5, IL-6, IL-10) were analyzed using real time PCR.

RESULTS

30 patients were enrolled in the study: 5 type I (80% female), 14 type II (71% female) and 11 controls (73% female). There were 14 decompressions (3 type I and 11 type II), 17 lid procedures (2 type I, 4 type II and 11 controls) and 10 ethmoidectomies (3 type I and 7 type II). The average ages were 45, 56 and 66 in the type I, type II and control groups, respectively. There was more TNF-alpha (p value 0.009) and IL-6 (p value 0.04) in ethmoid sinus cells of type II patients compared to ethmoid sinus cells of type I patients and a trend of higher expression of all cytokines in type II patients.

CONCLUSIONS

There is a trend towards greater mRNA expression of both Th1 and Th2 cytokines in both orbital fat and ethmoidal sinus tissue of type II patients compared to type I patients.

Roles of IL-10 in ocular inflammations: a review

INTRODUCTION

This review represents the current in vitro, in vivo, animal and human investigations on the roles of IL-10 in ocular inflammatory conditions.

MATERIALS AND METHODS

The data sources were literature reviews, including Pub Med, Medline, and ISI databases (since 1989 to mid-2012). Search items were, IL-10, chemokines, cytokines, alone or in combination with, serum, aqueous, vitreous eye, ocular, ocular tissues, ophthalmic, and review.

RESULTS

Ocular effects of IL-10 depend on the sources of the secretion and sites of the action. IL-10 plays important anti-inflammatory and especially anti-angiogenic activities in ocular tissues such as the conjunctiva, cornea, retina, choroid, and orbit.

CONCLUSION

IL-10 plays major anti-inflammatory and anti-angiogenic roles in most of the ocular inflammations. Also, IL-10 plays a role in development of anterior chamber-associated immune deviation (ACAID). Any manipulation of IL-10 for treatment purposes should be considered very cautiously due to its potential hazards to the immune system.

Immunotherapy in miscellaneous medical disorders Graves ophthalmopathy, asthma, and regional painful syndrome

In Graves ophthalmopathy, immunotherapy is offering an opportunity of reducing bad outcomes that lead to disfigurement and impairment of vision. These therapies are not perfect; however, we now have a chance to achieve better outcomes. In asthma, immune therapy using passive immunity targeting key proinflammatory cytokine/chemokines and medications of their effects has opened an avenue of research into a safe and durable therapy. Omalizumab appears to be safe and effective in clinical use. In regional pain syndrome, immune mechanisms may be involved in sustaining long-standing pain, and IVIG may moderate pain sensitivity by reducing immune activation.

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.

Thyroid eye disease

Thyroid eye disease (TED) is the most common cause of proptosis in adults, and should always be a consideration in patients with unexplained diplopia, pain, or optic nerve dysfunction. At least 80% of TED is associated with Graves disease (GD), and at least 50% of patients with GD develop clinically evident symptomatic TED. The most confusing patients for doctors of all subspecialties are the patients with eye symptoms and signs that precede serum evidence of a thyroid imbalance. Management of TED may include immunosuppressive medications, radiation, or surgery. Although the prognosis for optic nerve function is excellent, the restrictive dysmotility can result in permanent disability. Orbit and eyelid reconstruction are reserved for stable, inactive patients and are the final steps in minimizing facial alterations and enhancing the patient's daily functioning.

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.

The balance shift in Th1/Th2 related IL-12/IL-5 cytokines in Graves' disease during methimazole therapy

Th1 and Th2-like cytokines are involved in the pathogenesis of Graves' disease. The shift in balance in IL-12/IL-5 cytokines was applied in judging the immunological events in 74 patients with Graves' disease (50 had ophthalmopathy) during methimazole therapy and in 15 controls. The serum levels of IL-12 and IL-5 were measured with enzyme-linked immunosorbent assay in all Graves' patients. Twelve cases for IL-5 and 20 cases for IL-12 were positive. In Graves' patients only those without ophthalmopathy had higher levels of IL-12 when compared to controls (192.66 +/- 29.19 vs. 85.09 +/- 8.95 pg/ml, P < 0.04). After 2 months of methimazole therapy in Graves' patients without ophthalmopathy an increase in the ratio of IL-12 to IL-5 was also observed as compared to those with eye symptoms (91.78 +/- 34.14 vs. 20.72 +/- 6.36, P < 0.015). Age-related difference in the serum level of IL-5 could be demonstrated between Graves' patients without and those with ophthalmopathy aged < or = 35 years (4.89 +/- 0.57 vs. 50.14 +/- 20.2 pg/ml, P < 0.002). No association was found among the serum levels of IL-5 or IL-12, thyroid hormones and TSH receptor antibodies. The results demonstrated a difference in the balance shift of IL-12/IL-5 between Graves' patients with and without ophthalmopathy. The increased ratio of IL-12 to IL-5 after methimazole therapy could be explained by the elevation of serum IL-12 due to methimazole therapy and the age-related decrease of serum IL-5.

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).

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.

Analysis of peripheral blood T-cell subsets in active thyroid-associated ophthalmopathy: absence of effect of octreotide-LAR on T-cell subsets in patients with thyroid-associated ophthalmopathy

Thyroid-associated ophthalmopathy (TAO) is thought to be a T-cell-mediated autoimmune disorder. We sought to characterize abnormalities in the peripheral blood T-cell subsets in patients with TAO, and examine whether the long-acting somatostatin analogue, octreotide-LAR, treatment affects these cells. We analyzed peripheral blood T-cell subsets by flow cytometry in 26 euthyroid patients with moderately severe active TAO and 24 controls. Twenty-five of the patients with TAO were enrolled in a randomized trial to receive either 30 mg of octreotide-LAR (n = 11) or placebo (n = 14) every 4 weeks for 16 weeks; all 25 patients subsequently received octreotide-LAR 30 mg every 4 weeks from week 16 to 32. T-cell subsets were analysed at baseline, week 16, and week 32. At baseline, the relative percentage of CD4+ helper T-cells (p = 0.0003) and the CD4+/CD8+ ratio (p = 0.008) were significantly higher in patients with TAO compared to controls. Patients with TAO had higher naïve active T cells (CD45RA+, CD45RA+ CD4+) and lower memory T cells (CD45RO+, CD45RO+ CD4+) than controls. At weeks 16 and 32, there were no significant differences in any T-cell subsets between the octreotide-LAR-treated and placebo groups. These results support a role of T cell in the pathogenesis of TAO, and show that octreotide-LAR has no effect on T-cell subsets during 32-weeks of treatment.

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

T-cell-mediated immunity in thyroid-associated ophthalmopathy

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

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.

Animal models of thyroid-associated ophthalmopathy

Thyroid-associated ophthalmopathy (TAO) is an autoimmune condition most frequently associated with Graves' disease (GD). The thyrotropin receptor (TSHR) is an important target of the autoimmune response in both disorders. The last 5 years have seen some progress in the development of animal models, induced with TSHR preparations and reproducing some or all of the features of GD and TAO with variable incidence. The most promising approaches have used: (1) treatment of AKR/N mice with cells transfected with the homologous major histocompatibility complex class II molecule to the recipients and the full-length human or murine TSHR. Approximately 20% of mice develop thyroid-stimulating antibodies (TSAB) and increased thyroxine levels but no thyroiditis; (2) transfer of TSHR primed T cells to naive syngeneic recipients. Approximately 65% of BALBc mice develop thyroiditis and orbital changes similar to TAO; (3) genetic immunization of NMRI outbred mice with the full-length human TSHR. Approximately 20% of mice develop TSAB, hyperthyroidism, and orbital changes.

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

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

Understanding the immunology of Graves' ophthalmopathy. Is it an autoimmune disease?

The notion that Graves' ophthalmopathy is an autoimmune disease has been based primarily on the clinical associations between it and Graves' hyperthyroidism, and on the frequently beneficial response of the disease to immunosuppressive therapy. Recent advances in molecular biology have led to new insights into the pathogenesis that support an autoimmune basis for this condition. In particular, there is now compelling--although not definitive--evidence that, if verified, would represent disease transfer by thyroid-secreting hormone receptor-sensitized T cells. Future studies using animal models and in vitro systems will allow definitive identification of the immune cell types, autoantigens, and autoantibodies involved in the pathogenesis of Graves' ophthalmopathy.

Pathogenesis of ophthalmopathy in autoimmune thyroid disease

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