Graves orbitopathy: a perspective

An L-type calcium channel blocker nimodipine exerts anti-fibrotic effects by attenuating TGF-β1 induced calcium response in an in vitro model of thyroid eye disease

BACKGROUND

Thyroid eye disease (TED) is a vision-threatening autoimmune disorder. Orbital tissue fibrosis leading to intractable complications remains a troublesome issue in TED management. Exploration of novel therapeutic targets and agents to ameliorate tissue fibrosis is crucial for TED. Recent work suggests that Ca2+ signaling participates in tissue fibrosis. However, whether an alteration of Ca2+ signaling has a role in fibrogenesis during TED remains unclear. In this study, we aimed to investigate the role of Ca2+ signaling in the fibrogenesis process during TED and the potential therapeutic effects of a highly selective inhibitor of the L-type calcium channel (LTCC), nimodipine, through a TGF-β1 induced in vitro TED model.

METHODS

Primary culture of orbital fibroblasts (OFs) were established from orbital adipose connective tissues of patients with TED and healthy control donors. Real-time quantitative polymerase chain reaction (RT-qPCR) and RNA sequencing were used to assess the genes expression associated with LTCC in OFs. Flow cytometry, RT-qPCR, 5-ethynyl-2'-deoxyuridine (EdU) proliferation assay, wound healing assay and Western blot (WB) were used to assess the intracellular Ca2+ response on TGF-β1 stimulation, and to evaluate the potential therapeutic effects of nimodipine in the TGF-β1 induced in vitro TED model. The roles of Ca2+/calmodulin-dependent protein kinase II (CaMKII) and signal transducer and activator of transcription 1 (STAT1) in fibrogenesis during TED were determined by immunohistochemistry, WB, flow cytometry and co-immunoprecipitation assay. Selective inhibitors were used to explore the downstream signaling pathways.

RESULTS

LTCC inhibitor nimodipine blocked the TGF-β1 induced intracellular Ca2+ response and further reduced the expression of alpha-smooth muscle actin (α-SMA), collagen type I alpha 1 (Col1A1) and collagen type I alpha 2 (Col1A2) in OFs. Besides, nimodipine inhibited cell proliferation and migration of OFs. Moreover, our results provided evidence that activation of the CaMKII/STAT1 signaling pathway was involved in fibrogenesis during TED, and nimodipine inhibited the pro-fibrotic functions of OFs by down-regulating the CaMKII/STAT1 signaling pathway.

CONCLUSIONS

TGF-β1 induces an LTCC-mediated Ca2+ response, followed by activation of CaMKII/STAT1 signaling pathway, which promotes the pro-fibrotic functions of OFs and participates in fibrogenesis during TED. Nimodipine exerts potent anti-fibrotic benefits in vitro by suppressing the CaMKII/STAT1 signaling pathway. Our work deepens our understanding of the fibrogenesis process during TED and provides potential therapeutic targets and alternative candidate for TED.

Understanding Pathogenesis Intersects With Effective Treatment for Thyroid Eye Disease

CONTEXT

Thyroid eye disease (TED), a vision-threatening and disfiguring autoimmune process, has thwarted our efforts to understand its pathogenesis and develop effective and safe treatments. Recent scientific advances have facilitated improved treatment options.

OBJECTIVE

Review historically remote and recent advances in understanding TED.

DESIGN/SETTING/PARTICIPANTS

PubMed was scanned using search terms including thyroid-associated ophthalmopathy, thyroid eye disease, Graves' orbitopathy, autoimmune thyroid disease, and orbital inflammation.

MAIN OUTCOME MEASURES

Strength of scientific evidence, size, scope, and controls of clinical trials/observations.

RESULTS

Glucocorticoid steroids are widely prescribed systemic medical therapy. They can lessen inflammation-related manifestations of TED but fail to reliably reduce proptosis and diplopia, 2 major causes of morbidity. Other current therapies include mycophenolate, rituximab (anti-CD20 B cell-depleting monoclonal antibody), tocilizumab (interleukin-6 receptor antagonist), and teprotumumab (IGF-I receptor inhibitor). Several new therapeutic approaches have been proposed including targeting prostaglandin receptors, vascular endothelial growth factor, mTOR, and cholesterol pathways. Of potentially greater long-term importance are attempts to restore immune tolerance.

CONCLUSION

Despite their current wide use, steroids may no longer enjoy first-tier status for TED as more effective and better tolerated medical options become available. Multiple current and emerging therapies, the rationales for which are rooted in theoretical and experimental science, promise better options. These include teprotumumab, rituximab, and tocilizumab. Restoration of immune tolerance could ultimately become the most effective and safe medical management for TED.

Gypenosides Protect Orbital Fibroblasts in Graves Ophthalmopathy via Anti-Inflammation and Anti-Fibrosis Effects

Purpose

To investigate the effect of Gypenosides (Gyps) on the inflammation and fibrosis in orbital fibroblasts (OFs) in Graves ophthalmopathy (GO).

Methods

Bioinformatics analyses were performed to identify the enriched genes and signaling pathways related to Gyps function. For ex vivo experiments, OFs were cultured from orbital connective tissues from patients with GO. OF proliferation was estimated by Cell Counting Kit-8 assay. Effects of Gyps treatment on interleukin (IL)-1β-induced inflammation and transforming growth factor-β1 (TGF-β1)-induced fibrosis were evaluated by real-time quantitative PCR (RT-qPCR), enzyme-linked immunosorbent assay (ELISA), and Western blotting. OFs were treated with IL-1β or TGF-β1 in the absence or presence of Gyps pretreatment, and the levels of related mRNA or proteins were evaluated by RT-qPCR or ELISA.

Results

Eight inflammation-related target genes and nine fibrosis-related target genes were screened out. These genes were mainly enriched in pathways corresponding to inflammation and fibrosis, respectively. IL-1β-induced upregulation of inflammatory cytokines, and TGF-β-induced upregulation of fibrotic mediators in OFs were downregulated by Gyps. Moreover, Gyps reduced the activation of Toll like receptors 4/nuclear factor-κ B signaling and TGF-β1/SMAD2/SMAD4 signaling in GO OFs.

Conclusions

Gyps could protect GO-derived OFs against IL-1β-induced inflammation and TGF-β1-induced fibrosis. Thus Gyps might have therapeutic potential on inflammation and fibrosis in GO.

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.

Research on the Potential Mechanism of Gypenosides on Treating Thyroid-Associated Ophthalmopathy Based on Network Pharmacology

Thyroid-associated ophthalmopathy is the commonest orbital disease in adults. However, shortcomings still exist in treatments. The aim of this study was to identify the efficacy and potential mechanism of gypenosides in the treatment of thyroid-associated ophthalmopathy. The Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform was screened for active compounds of gypenosides, and targets were predicted using Swiss Target Prediction. The targets of thyroid-associated ophthalmopathy were obtained from Online Mendelian Inheritance in Man, Comparative Toxicogenomic Database and GeneCards Human gene database. Gene Ontology (GO), the Kyoto Encyclopedia of Genes and Genomes (KEGG) and Reactome Pathways were determined based on the common targets. Protein-protein interaction (PPI) network was constructed to further understand of relationship among target genes, compounds and proteins. Molecular docking was performed to investigate the binding ability between gypenosides and hub genes. A total of 70 targets for gypenosides and 804 targets for thyroid-associated ophthalmopathy were obtained with 8 common targets identified. GO analysis and KEGG pathway analysis revealed that the hub genes were enriched in JAK-STAT, while Reactome pathways analysis indicated genes enriched in interleukin pathways. PPI network showed STAT1, STAT3, and STAT4 were at the center. Additionally, molecular docking indicated that STAT1 and STAT3 display good binding forces with gypenosides. This study indicates that target genes mainly enriched in JAK-STAT signaling pathway, particularly in STATs, which can be combined with gypenosides. This may suggest that gypenosides have curative effect on thyroid-associated ophthalmopathy via the JAK-STAT pathway.

Treatment of adult Graves' disease

Treatment strategy in Graves' disease firstly requires recovery of euthyroid status by antithyroid therapy. Treatment modalities, precautions, advantages and side-effects are to be discussed with the patient. No particular treatment modality has demonstrated superiority. Pregnancy or pregnancy project affects choice of treatment and monitoring. Graves' orbitopathy is liable to be aggravated by iodine-131 treatment and requires pre-treatment assessment. Iodine-131 treatment aims at achieving hypothyroidism. Thyroid surgery for Graves' disease should preferably be performed by an expert team. In case of recurrence of hyperthyroidism, the various treatment options should be discussed with the patient. Empiric treatment of thyroid dermopathy uses local corticosteroids in occlusive dressing.

Acute liver damage following intravenous glucocorticoid treatment for Graves' ophthalmopathy

PURPOSE

Over the last years, there have been several reports on the occurrence of acute liver damage (ALD) in patients affected with Graves' ophthalmopathy (GO) receiving intravenous glucocorticoids (ivGCs). This article is aimed at reviewing the literature on this specific topic and reporting two new cases of ALD occurring in GO patients while on ivGCs.

METHODS

The terms "glucocorticoid therapy" and "Graves' Ophthalmopathy"/"Graves' Orbitopathy"/"Thyroid eye disease" were used both separately and in conjunction with the terms "liver disease," "liver damage," "hepatotoxicity," "liver failure," to search MEDLINE for articles published since the first report of ALD in 2000 and up to 2015.

RESULTS

ALD [defined as an increase in alanine aminotransferase (ALT) >300 U/L] during or after completion of ivGCs has been so far reported in 17 fully documented cases. Overall, one-half of those patients were diagnosed as having autoimmune hepatitis (AIH) and in the vast majority of the remaining cases a diagnosis of methylprednisolone(MP)-induced hepatotoxicity was suspected. The clinical course of liver injury varied from asymptomatic hypertransaminasemia in the vast majority of patients to fatal hepatic failure in four patients receiving higher (>8 g) cumulative doses of MP.

CONCLUSIONS

The overall risk of ALD is relatively low (~1 %), and seems higher using a single dose >0.5 g and a cumulative dose >8.5 g MP. Whenever ivGC treatment is required, serum liver enzymes, viral hepatitis markers, and autoantibodies related to AIH should be obtained prior to ivGC administration. Liver function should be monitored during ivGC and up to 6 months after the end of treatment. Prolonging observation after 6 months is likely unnecessary, since all cases of ALD so far reported always occurred well within this term.

Age and Dose Are Major Risk Factors for Liver Damage Associated with Intravenous Glucocorticoid Pulse Therapy for Graves' Orbitopathy

BACKGROUND

High-dose intravenous glucocorticoid (ivGC) pulse therapy, which is commonly used for Graves' orbitopathy (GO), has been associated with acute liver damage (ALD), resulting in a fatal outcome in a few cases. No certain risk factors for ALD have been established. Consequently, a large retrospective cohort study was performed.

METHODS

The relationship between ALD and several potential risk factors was assessed in 1076 consecutive patients with GO given ivGC. ALD was defined as an increase of alanine aminotransferase ≥300 IU/L.

RESULTS

Fourteen cases of ALD were recorded, resulting in a morbidity of 1.3%. Thirteen patients recovered and one died, resulting in a mortality of 0.09%. There was a significant, positive correlation of ALD with age and methylprednisolone acetate (MPA) cumulative dose, and ALD was more common (relative risk [RR]=2.8; p=0.05) in patients aged ≥53 years (9/420; 2.14%) than in those aged <53 years (5/656; 0.76%). In patients aged ≥53 years, there was a significant positive correlation of ALD with MPA cumulative dose, and with MPA dose per infusion. Thus, the frequency of ALD in this age group was greater (RR=3.48; p=0.04) in patients with a MPA dose per infusion ≥0.7 g (5/111, 4.5% vs. 4/308, 1.29%). Regardless of age, no cases of ALD were observed for MPA doses per infusion <0.57 g.

CONCLUSIONS

Age and MPA dose are significant risk factors for ALD, with the following practical implications. First, the total MPA cumulative dose should not exceed 8.5 g (the average dose in patients without ALD). Second, in patients aged ≥53 years, selection and observation should be quite strict. However, being aged ≥53 years should not be seen as an absolute contraindication to ivGC, especially in patients with severe GO, considering that the risk of ALD, although statistically significant, was relatively low. Third, the MPA dose should not exceed 0.57 g per infusion, a measure to be applied regardless of age.

Safety and Efficacy of Combined Immunosuppression and Orbital Radiotherapy in Thyroid-Related Restrictive Myopathy: Two-Center Experience

Purpose

To evaluate the safety and efficacy of oral steroids when combined with long-term oral azathioprine (AZA) and orbital radiotherapy in patients with active thyroid-related restrictive myopathy.

Methods

A total of 88 patients from adnexal outpatient clinics of Bristol Eye Hospital, UK, and 2nd Department of Ophthalmology at Aristotle University of Thessaloniki, Greece, were enrolled in a retrospective, twin-center study. All patients were diagnosed with active thyroid eye disease and concomitant restrictive myopathy. Treatment included oral AZA, low-dose steroids, and orbital radiotherapy (20 Gy). Clinical activity scores as well as orthoptic assessments were consistently evaluated. Clinical activity scores, improved levels of diplopia, and single muscle excursions were considered major criteria for treatment success.

Results

Clinical success was achieved in 54 (61.4%), 57 (64.8%), and 61 (69.3%) patients at 3-, 6-, and 12-month time points, respectively, after the initiation of the combined treatment. At 18 months following initiation of treatment, the percentage of treatment success reached 73.9% (n = 65). Nine patients developed AZA-related side effects. In 4 patients the drug had to be discontinued.

Conclusions

Combined immunosuppression with orbital radiotherapy appears to reduce morbidity in patients with marked restrictive myopathy by improving major motility parameters such as diplopia and duction amplitude.

Orbital fibrosis in a mouse model of Graves' disease induced by genetic immunization of thyrotropin receptor cDNA

The TSH receptor (TSHR) is the critical target for antibody production in Graves' disease (GD). Insulin-like growth factor 1 receptor (IGF1R) has been proposed as a second autoantigen in complications of GD such as orbitopathy. We attempted to induce orbital tissue remodeling in mice undergoing immunizations with plasmids encoding TSHR and IGF1R delivered by in vivo skeletal muscle electroporation, a procedure known to give a sustained, long-term antibody response. Female BALB/c mice were challenged with TSHR A-subunit or IGF1Rα subunit plasmid by injection and electroporation. Mice challenged with TSHR A-subunit plasmid resulted in high frequency (75%) of hyperthyroidism and thyroid-stimulating antibodies. But strikingly, immunization with TSHR A-subunit plasmid also elicited antibody to IGF1Rα subunit. Mice challenged in the same manner with IGF1Rα subunit plasmid produced strong antibody responses to IGF1R, but did not undergo any changes in phenotype. Simultaneous challenge by double antigen immunization with the two plasmids in distant anatomical sites reduced the incidence of hyperthyroidism, potentially as a consequence of antigenic competition. Thyroid glands from the TSHR A-subunit plasmid-challenged group were enlarged with patchy microscopic infiltrates. Histological analysis of the orbital tissues demonstrated moderate connective tissue fibrosis and deposition of Masson's trichrome staining material. Our findings imply that immunization with TSHR A-subunit plasmid leads to generation of IGF1R antibodies, which together with thyroid-stimulating antibodies may precipitate remodeling of orbital tissue, raising our understanding of its close association with GD.

Mesenchymal stem cells and potential applications in treating ocular disease

Mesenchymal stem cells (MSCs) are remarkable in stem cell biology. Not only do they have significant tissue regeneration potential, but more recently their paracrine effects (either innate or through genetic augmentation) have become increasingly recognized as useful therapeutic approaches. In particular, clinical roles for MSC therapy in neuroprotection and immune suppression are likely to emerge. These therapeutic effects will be particularly advantageous in work on neurological tissues, because MSC-based molecular therapy could overcome some of the difficulties of long-term drug delivery to tissues, such as the eye, which are relatively inaccessible to systemic delivery (for example due to the blood retina barrier). MSC therapy is, therefore, poised for significant impact in ocular molecular therapeutics, particularly for chronic diseases, such as retinal degeneration, glaucoma, and uveitis. Other molecular and tissue regeneration effects of MSCs are also likely to have impact in the management of ocular surface disease and oculoplastics.

Treatment of thyroid-associated orbitopathy with rituximab--a novel therapy for an old disease: case report and literature review

OBJECTIVE

To report the use of rituximab to treat thyroid-associated orbitopathy (TAO) in a patient with a concomitant B-cell organ-specific autoimmune disorder-the stiff person syndrome (SPS).

METHODS

We present a case report and a review of the related literature.

RESULTS

A 62-year-old man with SPS, latent autoimmune diabetes of the adult, and Graves-Basedow disease was referred to our medical center because of bilateral TAO. An ophthalmologic examination documented asymmetric bilateral NOSPECS (N = no signs or symptoms; O = only signs, no symptoms; S = soft tissue involvement; P = proptosis; E = extraocular muscle involvement; C = corneal involvement; and S = sight loss) class IV TAO (left eye>right eye) with a clinical activity score of 5 on a scale of 7. Magnetic resonance imaging of the orbits documented bilateral exophthalmos (left eye>right eye) due to retrobulbar fibroadipose infiltration, bilateral increase of extrinsic ocular muscle thickness, and enhancement of the left inferior rectus muscle on T2-weighted sequences. Because of concomitant incapacitating SPS and diet-controlled latent autoimmune diabetes of the adult, we excluded long-term corticosteroid therapy as an option and considered the use of rituximab, a mouse-human chimeric monoclonal antibody targeting the CD20 protein on pre-B and mature B lymphocytes. Rituximab was administered in accordance with the protocol for rheumatoid arthritis. During the subsequent 4 months, clinical signs and symptoms of TAO dramatically resolved (clinical activity score = 0 of 7) with a sustained improvement of the spastic paraparesis. The glutamic acid decarboxylase antibody titer remained high, and glycemic control and first-phase insulin secretion did not change.

CONCLUSION

Treatment of active TAO with rituximab should be considered when standard intravenous pulse glucocorticoid treatment is contraindicated or ineffective and when SPS or other organ-specific autoimmune disorders with involvement of humoral autoimmunity are present, inasmuch as more than 1 disease may benefit from the use of this chimeric monoclonal antibody.

The impact of bodily change on social behaviour in patients with thyroid-associated ophthalmopathy

Thyroid-associated ophthalmopathy (TAO) is characterized by the altered appearance of face and eyes and changed visual function. TAO has been described as alarming and crippling. It is well documented that TAO influences the patient's quality of life negatively. However, little is known about how the bodily change complicates the patient's social behaviour in everyday situations. The aim of this study was to explore how social behaviour is influenced by the bodily change and what it means to patients with TAO. An ethnographic study was conducted using in-depth interviews and participant observation. A total of 13 patients, nine women and four men, diagnosed with moderate to severe TAO were included. Data analysis was performed concurrently using grounded theory technique. The local ethics committee approved the study, and all participants gave written informed consent. The study reveals that the experience of bodily change had considerable consequences for patients' involvement with people and maintenance of social relations. Uncontrollable eyes were the dominating experience. It contained four sub-themes; the experience of changed facial communication, the experience of being somebody else, the experience of being clumsy among others and the experience of being cut off from the outside world. The bodily change affected people's attitude and behaviour towards them and their own ways of being with people. They struggled to change social behaviour and avoid withdrawal. In their struggle, they used seven different coping strategies. The study contributes to clarification of essential aspects of living with TAO. The condition of uncontrollable eyes may have serious consequences for patients' social behaviour and relationships with others. Early identification of the impact of bodily change and planned support may help prevent serious quality of life change.