Current concepts regarding Graves' orbitopathy

Dixon MRI-based quantitative parameters of extraocular muscles, intraorbital fat, and lacrimal glands for staging thyroid-associated ophthalmopathy

OBJECTIVE

To investigate the value of Dixon magnetic resonance imaging (MRI)-based quantitative parameters of extraocular muscles (EOMs), intraorbital fat (IF), and lacrimal glands (LGs) in staging patients with thyroid-associated ophthalmopathy (TAO).

METHODS

Two hundred patients with TAO (211 active and 189 inactive eyes) who underwent Dixon MRI for pretreatment evaluation were retrospectively enrolled and divided into training (169 active and 151 inactive eyes) and validation (42 active and 38 inactive eyes) cohorts. The maximum, mean, and minimum values of the signal intensity ratio (SIR), fat fraction (FF), and water fraction (WF) of EOMs, IF, and LGs were measured and compared between the active and inactive groups in the training cohort. Binary logistic regression analysis, receiver operating characteristic curve analysis, and the Delong test were used for further statistical analyses, as appropriate.

RESULTS

Compared with inactive TAOs, active TAOs demonstrated significantly greater EOM-SIRmax, EOM-SIRmean, EOM-SIRmin, IF-SIRmax, IF-SIRmean, LG-SIRmax, LG-SIRmean, EOM-WFmean, EOM-WFmin, IF-WFmax, IF-WFmean, and LG-WFmean and lower EOM-FFmax, EOM-FFmean, IF-FFmean, IF-FFmin, and LG-FFmean values (all p < 0.05). The EOM-SIRmean, LG-SIRmean, and LG-FFmean values were independently associated with active TAO (all p < 0.05). The combination of the EOM-SIRmean, LG-SIRmean, and LG-FFmean values showed better performance than the EOM-SIRmean value alone in staging TAO in both the training (AUC, 0.820 vs 0.793; p = 0.016) and validation (AUC, 0.751 vs 0.733, p = 0.341) cohorts.

CONCLUSION

Dixon MRI-based parameters of EOMs, LGs, and IF are useful for differentiating active from inactive TAO. The integration of multiple parameters can further improve staging performance.

CRITICAL RELEVANCE STATEMENT

In this study, the authors explored the combined value of quantitative parameters of EOMs, IF, and LGs derived from Dixon MRI in staging TAO patients, which can support the establishment of a proper therapeutic plan.

KEY POINTS

The quantitative parameters of EOMs, LGs, and IF are useful for staging TAO. The EOM-SIRmean, LG-SIRmean, and LG-FFmean values were found to independently correlate with active TAO. Joint evaluation of orbital tissue improved the ability to assess TAO activity.

Cyclosporin A inhibits PDGF-BB induced hyaluronan synthesis in orbital fibroblasts

Orbital connective tissue changes are contributors to the pathogenesis in thyroid eye disease (TED). Activated fibroblasts respond to immune stimuli with proliferation and increased hyaluronan (HA) production. Cyclosporin A (CsA) was reported to be beneficial in the treatment of TED. PDGF isoforms are increased in orbital tissue of TED patients and enhance HA production. We aimed to study the effect of CsA on HA production and hyaluronan synthase (HAS1, 2 and 3) and hyaluronidase (HYAL1 and 2) mRNA expressions in orbital fibroblasts (OFs). Measurements were performed in the presence or absence of CsA (10 μM) in unstimulated or PDGF-BB (10 ng/ml) stimulated OFs. The HA production of TED OFs (n = 7) and NON-TED OFs (n = 6) were measured by ELISA. The levels of mRNA expressions were examined using RT-PCR. The proliferation rate and metabolic activity were measured by BrdU incorporation and MTT assays, respectively. Treatment with CsA resulted in an average 42% decrease in HA production of OFs (p < 0.0001). CsA decreased the expression levels of HAS2, HAS3 and HYAL2 (p = 0.005, p = 0.005 and p = 0.002, respectively.) PDGF-BB increased HA production (p < 0.001) and HAS2 expression (p = 0.004). CsA could reduce the PDGF-BB-stimulated HA production (p < 0.001) and HAS2 expression (p = 0.005) below the untreated level. In addition, CsA treatment caused a decrease in proliferation potential (p = 0.002) and metabolic activity (p < 0.0001). These findings point to the fact that CsA affects HA metabolism via HAS2, HAS3 and HYAL2 inhibition in OFs. In addition to its well characterized immunosuppressant properties, CsA's beneficial effect in TED may be related to its direct inhibitory effect on basal and growth factor stimulated HA production.

The changing landscape of thyroid eye disease: current clinical advances and future outlook

AIMS

This review aims to provide an overview of the current understanding of TED and its pathophysiology. To describe the evidence base for current consensus treatment recommendations and newer biological therapies available as well as to present future therapeutic research.

METHODS

We reviewed and assessed the peer-reviewed literature placing particular emphasis on recent studies evaluating the pathophysiology of TED, landmark trials forming the basis of current management and recent clinical trials informing future therapeutics. Searched were made in MEDLINE Ovid, Embase Ovid, US National Institutes of Health Ongoing Trials Register and EU Clinical Trials Register. Keywords included: "Thyroid Eye Disease", "Graves Orbitopathy", "Thyroid Orbitopathy" and "Graves' Ophthalmopathy".

RESULTS AND CONCLUSIONS

The pathophysiology of TED involves a complex array of cellular and humoral based autoimmune dysfunction. Previous therapies have been broad-based acting as a blunt instrument on this mechanism with varying efficacy but often accompanied with a significant side effect profile. The recent development of targeted therapy, spearheaded by Teprotumumab has led to an array of treatments focusing on specific components of the molecular pathway optimising their impact whilst possibly minimising their side effect profile. Future challenges involve identifying the most effective target for each patient rather than any single agent being a panacea. Long-term safety profiles will require clarification as unintended immunological consequence downstream may become manifest as seen in other diseases. Finally, future novel therapeutics will entail significant expenditure and may lead to a divergence of available treatment modalities between healthcare systems due to funding disparities.

Profiling of carbonyl metabolic fingerprints in urine of Graves' disease patients based on atmospheric ionization mass spectrometry

Graves' disease (GD) is considered among the organ autoimmune diseases and is somewhat linked to other autoimmune and secondary diseases. Commonly used detection methods rely on identifying characteristic clinical features and abnormal biochemical markers, but they have certain limitations and may be affected by patient medication. In this study, a desorption separation ionization (DSI) device coupled with a linear ion trap mass spectrometer is introduced for effective detection and screening of urine from GD patients. To enhance the sensitivity of MS analysis, derivatization reagent is utilized as a labeling method. The MS signal is used for metabolic profiling, through which differential metabolites and pathways are identified. Subsequently, processing the acquired spectra with a machine learning algorithm enables successful differentiation of GD patients and healthy individuals. This method is believed to provide versatile and powerful technical support for effective detection on the scene. Notably, this method offers the advantage of achieving early and rapid diagnosis of thyroid-related diseases.

Immune checkpoints: new insights into the pathogenesis of thyroid eye disease

Thyroid eye disease (TED) is a disfiguring autoimmune disease characterized by changes in the orbital tissues and is caused by abnormal thyroid function or thyroid-related antibodies. It is the ocular manifestation of Graves' disease. The expression of thyroid-stimulating hormone receptor (TSHR) and the insulin-like growth factor-1 receptor (IGF-1 R) on the cell membrane of orbital fibroblasts (OFs) is responsible for TED pathology. Excessive inflammation is caused when these receptors in the orbit are stimulated by autoantibodies. CD34+ fibrocytes, found in the peripheral blood and orbital tissues of patients with TED, express immune checkpoints (ICs) like MHC II, B7, and PD-L1, indicating their potential role in presenting antigens and regulating the immune response in TED pathogenesis. Immune checkpoint inhibitors (ICIs) have significantly transformed cancer treatment. However, it can also lead to the occurrence of TED in some instances, suggesting the abnormality of ICs in TED. This review will examine the overall pathogenic mechanism linked to the immune cells of TED and then discuss the latest research findings on the immunomodulatory role of ICs in the development and pathogenesis of TED. This will offer fresh perspectives on the study of pathogenesis and the identification of potential therapeutic targets.

Predictive model for the progression of inactive thyroid eye disease: a retrospective study

PURPOSE

This study aimed to develop a model for predicting the progression of inactive thyroid eye disease (TED).

METHODS

We retrospectively analyzed 107 patients with inactive TED, who did not receive any TED treatment during the follow-up period of 3-6 months. A multivariable regression analysis was employed to examine the clinical risk factors influencing the progress of TED and a predictive model based on risk factors was established.

RESULTS

Seventeen (15.9%) patients had progressed at the last observation. Male (p = 0.024), having smoking history (p = 0.009), compound indicator combined the duration of TED and immunosuppressive treatment history before 3 months (p = 0.026) and more severe diplopia (p = 0.015) were found to be the potential risk factors for progression. Among the subset of patients who exhibited progression, there was a notable escalation in the severity of proptosis (p = 0.021), margin reflex distance-1 (p = 0.031), and clinical activity score (p = 0.011). The multivariable stepwise regression analysis identified positive smoking history as well as untreated and having a duration of TED > 12 months as independent risk factors of TED progression. A predictive model including these risk factors was built, with the AUC (Area Under Curve) score of 0.783.

CONCLUSIONS

The predictors of TED progression include smoking history and composite indicators of duration time and treatment history. Our model may provide recommendations for immunosuppressive therapy and prognostic predictions for inactive TED patients preparing for surgery.

Peripheral CD3+CD4+ T cells as indicators of disease activity in thyroid eye disease: age-dependent significance

PURPOSE

To provide an in-depth analysis of the association of peripheral lymphocytes and the disease activity of thyroid eye disease (TED).

METHODS

This retrospective study enrolled 65 active TED patients and 46 inactive TED patients. Comparative analyses of peripheral lymphocyte subsets were conducted between active and inactive patients. Subgroup analyses were performed based on sex, age, disease duration, and severity. Correlation analyses explored the associations between lymphocyte subsets and TED activity indicators. Prediction models for TED activity were established using objective indicators.

RESULTS

Significantly elevated levels of CD3+CD4+ T cells were observed in active TED patients compared to inactive patients (P = 0.010). Subgroup analyses further revealed that this disparity was most prominent in females (P = 0.036), patients aged 50 years and younger (P = 0.003), those with long-term disease duration (P = 0.022), and individuals with moderate-to-severe disease (P = 0.021), with age exerting the most substantial impact. Subsequent correlation analysis confirmed the positive association between CD3+CD4+ T cells and the magnetic resonance imaging indicator of TED activity among patients aged 50 years and younger (P = 0.038). The combined prediction models for TED activity, established using objective indicators including CD3+CD4+ T cells, yielded areas under curve of 0.786 for all patients and 0.816 for patients aged 50 years and younger.

CONCLUSIONS

Peripheral CD3+CD4+ T cells are associated with disease activity of TED, especially in patients aged 50 years and younger. Our study has deepened the understanding of the peripheral T cell profiles in TED patients.

Severity Identification of Graves Orbitopathy via Random Forest Algorithm

This study aims to establish a random forest model for detecting the severity of Graves Orbitopathy (GO) and identify significant classification factors. This is a hospital-based study of 199 patients with GO that were collected between December 2019 and February 2022. Clinical information was collected from medical records. The severity of GO can be categorized as mild, moderate-to-severe, and sight-threatening GO based on guidelines of the European Group on Graves' orbitopathy. A random forest model was constructed according to the risk factors of GO and the main ocular symptoms of patients to differentiate mild GO from severe GO and finally was compared with logistic regression analysis, Support Vector Machine (SVM), and Naive Bayes. A random forest model with 15 variables was constructed. Blurred vision, disease course, thyroid-stimulating hormone receptor antibodies, and age ranked high both in mini-decreased gini and mini decrease accuracy. The accuracy, positive predictive value, negative predictive value, and the F1 Score of the random forest model are 0.83, 0.82, 0.86, and 0.82, respectively. Compared to the three other models, our random forest model showed a more reliable performance based on AUC (0.85 vs. 0.83 vs. 0.80 vs. 0.76) and accuracy (0.83 vs. 0.78 vs. 0.77 vs. 0.70). In conclusion, this study shows the potential for applying a random forest model as a complementary tool to differentiate GO severity.

Late orbital radiotherapy combined with intravenous methylprednisolone in the management of long-lasting active graves' orbitopathy: a case report and literature review

PURPOSE

To present a case and review the literature on Orbital Radiotherapy (OR) combined with intravenous methylprednisolone, focusing on its late application in patients with long-lasting active Graves' Orbitopathy (GO). Additionally, we suggest emerging perspective for future research in this context.

METHOD

Relevant literature (randomized controlled studies, retrospective studies and reviews) was explored on PubMed from January 1973 to January 2024, searching "orbital radiotherapy" & "Graves disease".

RESULTS

OR is a well-established second-line treatment for moderate-to-severe active GO, providing response rates comparable to glucocorticoids. Its anti-inflammatory effect makes OR particularly suitable for early active GO, and when combined with glucocorticoids, outcomes are synergistically improved. The emergence of the new Volumetric Modulated Arc Image-Guided Radiation Therapy (VMAT-IGRT) technique enables precise radiation delivery to the target, significantly reducing associated toxicity. This technological advancement enhances the feasibility of radiotherapy in benign diseases like GO. A retrospective study indicated that late OR in patients with long-lasting active GO may improve diplopia and visual acuity, decreasing disease activity. Our case report supports this conclusion.

CONCLUSIONS

This report and literature review underscores the importance of considering late OR combined with intravenous methylprednisolone as a viable treatment option for GO patients with prolonged disease activity, emphasizing the crucial role of personalized therapy in managing GO. However, further investigations are warranted to validate this approach in cases of long-lasting active GO.

Safety of non-standard regimen of systemic steroid therapy in patients with Graves' orbitopathy: a single-centre experience

BACKGROUND

Graves' orbitopathy (GO) is an autoimmune disorder of the orbit and retro-ocular tissues and the primary extrathyroidal manifestation of Graves' disease. In moderate-to-severe and active GO iv glucocorticoids (GCs) are recommended as first-line treatment. The aim was to assess the safety profile of methylprednisolone administered intravenously for three consecutive days at 1 g in patients with active, moderate-to-severe or sight-threatening Graves' orbitopathy.

METHODS

We retrospectively evaluated 161 medical records of patients with GO treated with high-dose systemic GCs in the Department of Endocrinology, Metabolic Disorders, and Internal Medicine in Poznań between 2014 and 2021. Clinical data included age, gender, laboratory results, activity and severity of GO, smoking status, disease duration, and presented side effects.

RESULTS

The presence of mild side effects was observed during 114 (71%) hospitalizations. The most common complications were hyperglycemia (n = 95) and elevated aminotransferases (n = 31). Increased levels of aminotransferases were more likely observed in smokers and GO duration above 12 months. Based on the multivariate logistic regression, higher TRAb and CAS values were significantly associated with lower odds of hyperglycemia. In turn, the increased odds of elevated aminotransferases were significantly correlated with higher initial ALT levels, female gender, and GO duration above 12 months. In addition, the multidimensional correspondence analysis (MPA) showed that GO patients who declared smoking and had not L-ornithine L-aspartate applied demonstrated a higher probability of elevated aminotransferases.

CONCLUSIONS

Active GO treatment with high-dose systemic GCs is not associated with serious side effects. Hyperglycemia is the most common steroid-induced complication.

Statins and thyroid eye disease (TED): a systematic review

PURPOSE

Thyroid eye disease (TED) is the foremost extrathyroidal manifestation of Graves' disease (GD). Currently, available treatments do not entirely prevent the long-term consequences of TED and have distinct disadvantages. Therefore, this systematic review explored available evidence regarding the efficacy of statins in preventing and treating TED.

METHODS

Relevant studies investigating statin usage in patients with GD or TED were identified by searching Medline (Pubmed and Ovid), Scopus, Web of Science, ProQuest, and Cochrane Library databases (from the database inception to September 2023). The review was done according to the PRISMA statement. Web searching was done independently by two investigators. Two researchers independently extracted the data, and any disagreement was adjudicated by consensus. Based on the study design, the studies' quality appraisal was done using the Newcastle-Ottawa Scale (NOS) and Version 2 of the Cochrane risk-of-bias tool (RoB2).

RESULTS

The literature search identified 145 publications, of which four met the inclusion criteria (Three retrospective cohort studies and one randomized clinical trial) and were reviewed in full text. The two retrospective cohort studies demonstrated the beneficial effects of statins on TED in newly diagnosed GD Stein et al. showed that statins, regardless of the type, prevent or delay TED (HR: 0.74 (0.65-0.84)), especially in men or treatment duration of more than one year. Nilsson et al. fascinatingly revealed that at least 60 days of statin usage in the preceding year could decrease the risk of TED development by around 40%. One RCT showed a higher treatment response for active moderate-to-severe TED in patients with hypercholesterolemia who took atorvastatin 20 mg in addition to ivGC for 24 weeks without any increase in serious side effects. The retrospective study revealed that the need for reconstructive surgery was reduced in patients with severe TED who received statin therapy.

CONCLUSION

Statin therapy could be a potential adjunctive modality for preventing and treating TED.

TRIAL REGISTRATION

PROSPERO registration number: CRD42022315522.

Application of quantitative orbital analysis to assess the activity of Graves' ophthalmopathy

This study aimed to evaluate the diagnostic value of uptake ratios in the extraocular muscles (EOMs), lacrimal glands, and optic nerves to detect the inflammation activity of Graves' ophthalmopathy (GO) using quantitative analysis of 99m technetium (99mTc)-labeled diethylene triamine pentaacetic acid (DTPA) orbital single-photon emission computed tomography/computed tomography (SPECT/CT) images. The patients were categorized into an active stage (clinical activity score ≥ 3/7, n=23) or an inactive stage (clinical activity score < 3/7, n=38), based on their clinical activity score. The uptake ratio was manually determined by placing a region of interest within the area of highest uptake, as agreed upon by consensus, in the EOMs, lacrimal gland, and optic nerve on SPECT images corrected for CT attenuation. Patients with active GO exhibited significantly higher uptake ratios in the EOMs, lacrimal glands, and optic nerves compared to patients with inactive GO (all P < 0.01). These parameters have been proven effective in differentiating between active and inactive disease.

Immunological Processes in the Orbit and Indications for Current and Potential Drug Targets

Thyroid eye disease (TED) is an extrathyroidal manifestation of Graves' disease (GD). Similar to GD, TED is caused by an autoimmune response. TED is an autoimmune inflammatory disorder of the orbit and periorbital tissues, characterized by upper eyelid retraction, swelling, redness, conjunctivitis, and bulging eyes. The pathophysiology of TED is complex, with the infiltration of activated T lymphocytes and activation of orbital fibroblasts (OFs) and autoantibodies against the common autoantigen of thyroid and orbital tissues. Better understanding of the multifactorial pathogenesis of TED contributes to the development of more effective therapies. In this review, we present current and potential drug targets. The ideal treatment should slow progression of the disease with as little interference with patient immunity as possible. In the future, TED treatment will target the immune mechanism involved in the disease and will be based on a strategy of restoring tolerance to autoantigens.

A Randomized Clinical Trial of Intravenous Methylprednisolone With 2 Protocols in Patients With Graves Orbitopathy

CONTEXT

Intravenous glucocorticoid (IVGC) is an accessible and affordable treatment for Graves orbitopathy (GO); the 4.5-g protocol is well studied, but many details of treatment protocols need to be clarified.

OBJECTIVE

To compare the efficacy and safety of weekly and monthly protocol of IVGC in GO.

METHODS

A prospective, randomized, observer-masked, single-center clinical trial, followed up to week 24, at the third affiliated hospital of Southern Medical University; 58 patients with active and moderate to severe GO, aged 18-60 years old, who had not received relevant treatment were included. The intervention was weekly protocol or monthly protocol of IVGC; both received a cumulative dose of methylprednisolone 4.5 g and had a duration of 12 weeks. The overall effective rate, improvement of quality of life (QOL) and signal intensity ratio (SIR) were measured.

RESULTS

There was no significant difference in the effective rate between the 2 groups at week 12 and week 24 (86.21% vs 72.41%, P = .195; 86.21% vs 82.61%, P = .441), there was no significant difference in the improvement of clinical activity score, exophthalmos, soft tissue involvement, diplopia, and QOL. At week 24, the mean SIR and maximum SIR of the 2 groups were lower than those before treatment, and there were no statistically significant difference between the 2 groups. There was no significant difference in the incidence of adverse events between the 2 groups (31.03% vs 27.59%, P = .773).

CONCLUSION

The efficacy and safety of the 2 protocols are comparable; the monthly protocol could be used as an alternative to the weekly protocol.

The Use of Tissue-on-Chip Technology to Focus the Search for Extracellular Vesicle miRNA Biomarkers in Thyroid Disease

Small extracellular vesicles (sEVs) contain microRNAs (miRNAs) which have potential to act as disease-specific biomarkers. The current study uses an established method to maintain human thyroid tissue ex vivo on a tissue-on-chip device, allowing the collection, isolation and interrogation of the sEVs released directly from thyroid tissue. sEVs were analysed for differences in miRNA levels released from benign thyroid tissue, Graves' disease tissue and papillary thyroid cancer (PTC), using miRNA sequencing and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) to identify potential biomarkers of disease. Thyroid biopsies from patients with benign tissue (n = 5), Graves' disease (n = 5) and PTC (n = 5) were perfused with medium containing sEV-depleted serum for 6 days on the tissue-on-chip device. During incubation, the effluents were collected and ultracentrifuged to isolate sEVs; miRNA was extracted and sequenced (miRNASeq). Out of the 15 samples, 14 passed the quality control and miRNASeq analysis detected significantly higher expression of miR-375-3p, miR-7-5p, miR-382-5p and miR-127-3p in the sEVs isolated from Graves' tissue compared to those from benign tissue (false discovery rate; FDR p < 0.05). Similarly, miR-375-3p and miR-7-5p were also detected at a higher level in the Graves' tissue sEVs compared to the PTC tissue sEVs (FDR p < 0.05). No significant differences were observed between miRNA in sEVs from PTC vs. those from benign tissue. These results were supported by Quantitative Reverse Transcriptase Polymerase Chain Reaction (qRT-PCR). The novel findings demonstrate that the tissue-on-chip technology is a robust method for isolating sEVs directly from the tissue of interest, which has permitted the identification of four miRNAs, with which further investigation could be used as biomarkers or therapeutic targets within thyroid disease.

Immune-related visual dysfunction in thyroid eye disease: a combined orbital and brain neuroimaging study

OBJECTIVES

To investigate the pathological interplay between immunity and the visual processing system (VPS) in thyroid eye disease (TED).

METHODS

A total of 24 active patients (AP), 26 inactive patients (IP) of TED, and 27 healthy controls (HCs) were enrolled. Orbital magnetic resonance imaging (MRI) and resting-state functional MRI (rs-fMRI) were conducted for each participant. Multiple MRI parameters of the intraorbital optic nerve (ON) were assessed. The amplitude of low-frequency fluctuations (ALFF) and regional homogeneity (ReHo) were calculated. Correlation analyses were carried out on the above parameters and clinical characteristics.

RESULTS

Visual functioning scores differentiated between the AP and IP groups. The ON subarachnoid space and ON sheath diameter were significantly higher in AP than in IP. Six vision-related brain regions were identified in TED patients compared with HCs, including right calcarine (CAL.R), right cuneus (CUN.R), left postcentral gyrus (PoCG.L), right middle temporal gyrus (MTG.R), left superior frontal gyrus (SFG.L), and left caudate (CAU.L). The brain activity of MTG.R, SFG.L, and CAU.L differentiated between the AP and IP groups. The correlation analysis revealed a close association among the vision-related brain regions, MRI parameters of ON, and clinical characteristics in AP and IP, respectively.

CONCLUSIONS

Combined orbital and brain neuroimaging revealed abnormalities of the VPS in TED, which had a close correlation with immune statuses. Vision-related brain regions in TED might be possibly altered by peripheral immunity via a direct or indirect approach.

CLINICAL RELEVANCE STATEMENT

The discovery of this study explained the disparity of visual dysfunction in TED patients with different immune statuses. With the uncovered neuroimaging markers, early detection and intervention of visual dysfunction could be achieved and potentially benefit TED patients.

KEY POINTS

• Patients with different immune statuses of thyroid eye disease varied in the presentation of visual dysfunction. • The combined orbital and brain neuroimaging study identified six altered vision-related brain regions, which had a significant correlation with the MRI parameters of the intraorbital optic nerve and immunological characteristics. • Peripheral immunity might possibly give rise to alterations in the central nervous system part of the visual processing system via a direct or indirect approach.

Differentially expressed genes in orbital adipose/connective tissue of thyroid-associated orbitopathy

Background

Thyroid-associated orbitopathy (TAO) is a disease associated with autoimmune thyroid disorders and it can lead to proptosis, diplopia, and vision-threatening compressive optic neuropathy. To comprehensively understand the molecular mechanisms underlying orbital adipogenesis in TAO, we characterize the intrinsic molecular properties of orbital adipose/connective tissue from patients with TAO and control individuals.

Methods

RNA sequencing analysis (RNA-seq) was performed to measure the gene expression of orbital adipose/connective tissues of TAO patients. Differentially expressed genes (DEGs) were detected and analyzed through Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, and Gene Set Enrichment Analysis (GSEA). The protein-protein interaction (PPI) network was constructed using the STRING database, and hub genes were identified by the Cytoscape plug-in, cytoHubba. We validated several top DEGs through quantitative real-time polymerase chain reaction (qRT-PCR).

Results

We identified 183 DEGs in adipose tissue between TAO patients (n = 3) and control patients (n = 3) through RNA sequencing, including 114 upregulated genes and 69 downregulated genes. The PPI network of these DEGs had 202 nodes and 743 edges. PCR-based validation results of orbital adipose tissue showed multiple top-ranked genes in TAO patients (n = 4) are immune and inflammatory response genes compared with the control individual (n = 4). They include ceruloplasmin isoform x3 (CP), alkaline tissue-nonspecific isozyme isoform x1 (ALPL), and angiotensinogen (AGT), which were overrepresented by 2.27- to 6.40-fold. Meanwhile, protein mab-21-like 1 (MAB21L1), phosphoinositide 3-kinase gamma-subunit (PIK3C2G), and clavesin-2 (CLVS2) decreased by 2.6% to 32.8%. R-spondin 1 (RSPO1), which is related to oogonia differentiation and developmental angiogenesis, was significantly downregulated in the orbital muscle tissues of patients with TAO compared with the control groups (P = 0.024).

Conclusions

Our results suggest that there are genetic differences in orbital adipose-connective tissues derived from TAO patients. The upregulation of the inflammatory response in orbital fat of TAO may be consistent with the clinical phenotype like eyelid edema, exophthalmos, and excess tearing. Downregulation of MAB21L1, PIK3C2G, and CLVS2 in TAO tissue demonstrates dysregulation of differentiation, oxidative stress, and developmental pathways.

Statins in Graves Orbitopathy: A New Therapeutic Tool

PURPOSE

Graves orbitopathy (GO) is the most common extrathyroidal manifestation of Graves disease. Although its pathogenesis is not fully elucidated, GO is commonly considered an autoimmune disease due to loss of self-tolerance against autoantigens shared by thyroid epithelial cells and orbital fibroblasts. High-dose intravenous glucocorticoids (ivGCs) are the most used treatment for moderate-to-severe, active GO, but the addition of other immunomodulating treatments can improve the efficacy of ivGCs. Among the various risk factors that can affect the occurrence of GO, cholesterol may be worthy of interest. Since 2015 the role of cholesterol and cholesterol-lowering medications has been investigated. The purpose of this review is to discuss this topic, thereby offering new therapeutic opportunities for patients with GO.

METHODS

We searched PubMed for studies published between January 1, 1980 and June 1, 2023, using the search terms "Graves orbitopathy," "thyroid eye disease," "Graves ophthalmopathy," "thyroid ophthalmopathy," "thyroid-associated ophthalmopathy," "endocrine ophthalmopathy," "cholesterol," "lipids," "statins," "low-density lipoprotein," "atorvastatin," and "cholesterol-lowering drugs." Only English-language articles were included.

RESULTS

A correlation between low-density lipoprotein cholesterol and the risk of GO development has been reported. Furthermore, low-density lipoprotein cholesterol has been proposed as a risk factor that can affect the course of GO and the response to ivGCs. The protective role of cholesterol-lowering medications in preventing GO has been also investigated. Statin treatment was found to have potential benefits in reducing the risk of GO in patients with Graves disease. Given these findings, measurement of low-density lipoprotein cholesterol and treatment of hypercholesterolemia in patients with moderate-to-severe, active GO may be considered before starting ivGCs administration. Recently, a randomized clinical trial aimed at investigating the effects of statins in GO suggested that the addition of oral atorvastatin to ivGCs improves the overall outcome of moderate-to-severe, active GO in hypercholesterolemic patients given ivGCs.

CONCLUSIONS

Overall, statins seem to have a preventive and therapeutic role in moderate-to-severe active GO. Their efficacy can be related to cholesterol-lowering activity, pleiotropic actions, and interaction with methylprednisolone.

Thyroid Eye Disease: Epidemiology, Natural History, and Risk Factors

BACKGROUND

Thyroid eye disease (TED) is an autoimmune disorder of the orbit and the most frequent extrathyroidal manifestation of Graves' disease but it may rarely occur in euthyroid/hypothyroid patients with chronic autoimmune thyroiditis.

EPIDEMIOLOGY

TED is a relatively infrequent disorder, particularly in its severe forms. Men tend to have more severe TED at an older age. The prevalence of TED is lower than in the past among patients with recent onset Graves' hyperthyroidism, and moderate-to-severe forms requiring aggressive treatments are no more than 5% to 6% of all cases.

NATURAL HISTORY

After an initial inflammatory (active) phase and a plateau phase, TED stabilizes and eventually inactivates (inactive or burnt-out phase) after an estimated period of 18-24 months. Minimal-to-mild TED often remits spontaneously, but complete restitutio ad integrum almost never occurs when TED is more than mild.

RISK FACTORS

Several risk factors contribute to its development on a yet undefined genetic background. Cigarette smoking is the most important of them, but thyroid dysfunction (both hyper- and hypothyroidism), radioactive iodine therapy (if not accompanied by low-dose steroid prophylaxis), elevated thyrotropin receptor antibodies, and, probably, hypercholesterolemia represent relevant modifiable risk factors. Early diagnosis, control and removal of modifiable risk factors, and early treatment of mild forms of GO (local treatment and selenium) may effectively limit the risk of progression to more severe forms.

Thyroid Eye Disease and Its Association With Diabetes Mellitus: A Major Review

PURPOSE

Thyroid eye disease (TED) associated with diabetes mellitus (DM) presents unique challenges. DM is a risk factor for TED. Standard management of TED with glucocorticoids (GC), orbital radiation, or teprotumumab can cause adverse events in poor glycemic control. The authors reviewed the literature on the relationship between TED and DM and the management of co-existing diseases.

METHODS

The authors searched PubMed with keywords "thyroid eye disease," "diabetes mellitus," and similar terms from 2013 to 2022. The authors included relevant studies after screening the abstracts. Additional references to the selected studies were included where applicable. Data were extracted from the final articles according to the preplanned outline of the review.

RESULTS

The initial search yielded 279 abstracts. The final review included 93 articles. TED and DM interact at multiple levels-genetic, immunologic, cellular, nutritional, and metabolic. Both DM and thyroid dysfunction exacerbate the morbidity caused by the other. Metabolic factors also affect the inflammatory pathway for TED. Patients with DM develop TED with greater frequency and severity, necessitating interventions for vision salvage. Agents (GC, teprotumumab, or radiation) used for TED are often unsuitable for treatment with DM, especially if there is poor glycemic control or diabetic retinopathy. There were no studies on using steroid-sparing agents in TED with DM.

CONCLUSION

TED and DM co-exist because of multiple intersections in the pathophysiology. Challenges in the treatment include increased TED severity and risk of hyperglycemia and retinopathy. Multidisciplinary teams best undertake treatment of TED with DM.

Regulatory T Cells in the Pathogenesis of Graves' Disease

Maintaining a delicate balance between the prompt immune response to pathogens and tolerance towards self-antigens and commensals is crucial for health. T regulatory (Treg) cells are pivotal in preserving self-tolerance, serving as negative regulators of inflammation through the secretion of anti-inflammatory cytokines, interleukin-2 neutralization, and direct suppression of effector T cells. Graves' disease (GD) is a thyroid-specific autoimmune disorder primarily attributed to the breakdown of tolerance to the thyroid-stimulating hormone receptor. Given the limitations of currently available GD treatments, identifying potential pathogenetic factors for pharmacological targeting is of paramount importance. Both functional impairment and frequency reduction of Tregs seem likely in GD pathogenesis. Genome-wide association studies in GD have identified polymorphisms of genes involved in Tregs' functions, such as CD25 (interleukin 2 receptor), and Forkhead box protein P3 (FOXP3). Clinical studies have reported both functional impairment and a reduction in Treg frequency or suppressive actions in GD, although their precise involvement remains a subject of debate. This review begins with an overview of Treg phenotype and functions, subsequently delves into the pathophysiology of GD and into the existing literature concerning the role of Tregs and the balance between Tregs and T helper 17 cells in GD, and finally explores the ongoing studies on target therapies for GD.

Application of Quantitative MRI in Thyroid Eye Disease: Imaging Techniques and Clinical Practices

Thyroid eye disease (TED) is a complex autoimmune disorder that impairs various orbital structures, leading to cosmetic damage and vision loss. Magnetic resonance imaging (MRI) is a fundamental diagnostic tool utilized in clinical settings of TED, for its accurate demonstration of orbital lesions and indication of disease conditions. The application of quantitative MRI has brought a new prospect to the management and research of TED, offering more detailed information on morphological and functional changes in the orbit. Therefore, many researchers concentrated on the implementation of different quantitative MRI techniques on TED for the exploration of clinical practices. Despite the abundance of studies utilizing quantitative MRI in TED, there remain considerable barriers and disputes on the best exploitation of this tool. This could possibly be attributed to the complexity of TED and the fast development of MRI techniques. It is necessary that clinical and radiological aspects of quantitative MRI in TED be better integrated into comprehensive insights. Hence, this review traces back 30 years of publications regarding quantitative MRI utilized in TED and elucidates this promising application in the facets of imaging techniques and clinical practices. We believe that a deeper understanding of the application of quantitative MRI in TED will enhance the efficacy of the multidisciplinary management of TED. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY: Stage 3.

Significance of HLA in Graves' disease and Graves' orbitopathy in Asian and Caucasian populations - a systematic review

Introduction

Graves' disease (GD) and Graves' orbitopathy (GO) development were suspected to be HLA-related in both Asian and Caucasian populations. However, most studies were performed with application of serological methods or low resolution genetic typing, which led to inconsistent results even among the same population. The present review is intended to summarize the state-of-art knowledge on the HLA significance in GD and GO in Asians and Caucasians, as well as to find the most significant alleles for each of the populations.

Methods

PubMed was searched for relevant articles using the following search terms: HLA plus thyroid-associated ophthalmopathy or Graves' disease or Graves' orbitopathy or thyroid eye disease or thyroid-associated orbitopathy.

Results

In Asian population GD was found to be associated mostly with B*46:01, DPB1*05:01, DRB1*08:02/03, DRB1*16:02, DRB1*14:03, DRB1*04:05, DQB1*05:02 and DQB1*03:03, while DRB1*07:01, DRB1*01:01, DRB1*13:02, DRB1*12:02 are potentially protective. HLA-B*38:02, DRB1*16:02, DQA1*01:02, DQB1*05:02 can be considered associated with increased risk of GO in Asians, while HLA-B*54:01 may play protective role. In Caucasians, C*07:01, DQA1*05:01, DRB1*03, DQB1*02:01 are associated with GD risk while DRB1*07:01, DQA1*02:01 may be protective. Significance of HLA in the course of GD and novel aspects of HLA amino acid variants and potential HLA-based treatment modalities were also discussed.

Increased plasma levels of soluble programmed death ligand 1 (sPD-L1) and fibroblast growth factor 23 (FGF-23) in patients with Graves' ophthalmopathy in comparison to hyperthyroid patients without Graves' ophthalmopathy

BACKGROUND

Management of Graves' ophthalmopathy (GO) is still a challenge in Graves' disease (GD). Moreover, 40% of GD patients show radiological muscle enlargement without clinically apparent GO. Delayed treatment of GO may lead to deterioration in prognosis.

METHODS

Thirty GD patients with overt hyperthyroidism were included in this study, 17 of whom either had GO at diagnosis or developed GO during the study period. Samples were collected at the beginning of the study, at 6 months, and at 24 months. Plasma samples were analyzed for 92 cytokines using the Olink Target 96 inflammation panel.

RESULTS

After adjustment for multiplicity testing using the false discovery rate approach, soluble programmed death ligand 1 (sPD-L1) and fibroblast growth factor 23 (FGF-23) were significantly elevated in GO patients.

CONCLUSION

Using a broad cytokine panel we show that patients with Graves' ophthalmopathy have elevated PD-L1 and FGF-23 levels. The findings support previous suggestions that PD-L1 may serve as a treatment target.

The Adverse Effects Profile of Teprotumumab

CONTEXT

Teprotumumab therapy for thyroid eye disease (TED) patients represents a major step forward. It targets and inhibits the insulin-like growth factor-1 receptor (IGF-1R), and its effectiveness is based on its interconnectedness with the thyrotropin receptor. However, IGF-1R has a ubiquitous expression and several adverse effects have been reported with teprotumumab use.

OBJECTIVE

Describing these adverse effects for better understanding is the purpose of this review.

METHODS

We reviewed the oncological studies in which teprotumumab was initially used. Subsequently we reviewed the clinical trials for TED and then the case series and case reports associated with teprotumumab use since it is US Food and Drug Administration approval (January 2020). We focused on common and/or serious adverse effects reported with the use of teprotumumab.

RESULTS

We described the common occurrence of hyperglycemia (10%-30% incidence), its risk factors and suggested management. Hearing changes are described, a broad spectrum from mild ear pressure to hearing loss (sensorineural mechanism). Risk factors, suggested monitoring, and possible upcoming therapies are reviewed. We also reviewed data on fatigue, muscle spasms, hair loss, weight loss, gastrointestinal disturbances, menstrual changes, and infusion reactions. We noted some discrepancies between adverse effects in oncological studies vs studies focused on TED, and we aimed to explain these differences.

CONCLUSION

The use of teprotumumab should consider patient's values and preferences in balancing the expected benefit with these potential risks. Future drugs targeting IGF-1R should investigate these adverse effects for a possible class effect. Combination therapies with different agents hopefully will be identified that maximize benefits and minimize risks.

Tocilizumab improves clinical outcome in patients with active corticosteroid-resistant moderate-to-severe Graves' orbitopathy: an observational study

Background

Graves' orbitopathy (GO) is an autoimmune disorder affecting the orbital fat and muscles. A significant role of IL-6 in the pathogenesis of GO has been described and tocilizumab (TCZ), an IL-6 inhibitor targeting IL-6R has been given in some patients. The aim of our case study was to evaluate the therapeutic outcome of TCZ in non-responders to first line treatments with corticosteroids.

Methods

We conducted an observational study of patients with moderate to severe GO. Twelve patients received TCZ in intravenous infusions at a dose of 8mg/kg every 28 days for 4 months and followed up for additionally 6 weeks. The primary outcome was improvement in CAS by at least 2 points, 6 weeks after the last dose of TCZ. Secondary outcomes included CAS <3 (inactive disease) 6 weeks after TCZ last dose, reduced TSI levels, proptosis reduction by > 2mm and diplopia response.

Results

The primary outcome, was achieved in all patients 6 weeks after treatment course. Furthermore all patients had inactive disease 6 weeks after treatment cessation. Treatment with TCZ reduced significantly median CAS by 3 units (p=0.002), TSI levels by 11.02 IU/L (p=0.006), Hertel score on the right eye by 2.3 mm (p=0.003), Hertel score on the left eye by 1.6 mm (p=0.002), while diplopia persisted in fewer patients (25%) after treatment with TCZ (not statistically significant, p=0.250). After treatment with TCZ, there was a radiological improvement in 75% of patients, while 16.7% showed no response, and in 8.3% of patients deterioration was established.

Conclusion

Tocilizumab appears to be a safe and cost effective therapeutic option for patients with active, corticosteroid-resistant, moderate to severe Graves' orbitopathy.

Associations between Lipid Profiles and Graves' Orbitopathy can Be HLA-Dependent

The risk of Graves' orbitopathy (GO) is related to the human leukocyte antigen (HLA) profile and was demonstrated to be increased in patients with elevated total cholesterol (TC) and/or low-density lipoprotein (LDL) cholesterol. We hypothesized that there were some HLA alleles that were related to both GO and TC and/or LDL levels. Therefore, the aim of the study was to compare the TC/LDL results in patients in whom GO-related HLA alleles were present to those in whom they did not occur. HLA classes were genotyped using a next-generation sequencing method in 118 patients with Graves' disease (GD), including 63 and 55 patients with and without GO, respectively. Lipid profiles were assessed at the time of the GD diagnosis. A significant correlation between the presence of GO high-risk alleles (HLA-B*37:01 and C*03:02) and higher TC/LDL levels was found. Additionally, the presence of alleles associated with non-GO GD (HLA-C*17:01 and B*08:01), as well as alleles in linkage disequilibrium with B*08:01 (i.e., HLA-DRB1*03:01 and DQB1*02:01), was correlated with lower TC levels. These results further confirm the significance of TC/LDL in the risk of GO development and provide evidence that associations between TC/LDL and GO can be HLA-dependent.

Effect of thyroid hormone status on complete blood cell count-derived inflammatory biomarkers in patients with moderate-to-severe Graves' ophthalmopathy

PURPOSE

To evaluate the systemic inflammation in moderate-to-severe Graves' ophthalmopathy patients with abnormal thyroid function by using complete blood cell count-derived inflammatory biomarkers and compare to moderate-to-severe GO patients with regulated thyroid function and healthy controls. The second aim is to evaluate the relationship of complete blood cell count-derived inflammatory biomarkers with clinical findings in moderate-to-severe GO.

METHODS

In this retrospective study, 90 GO patients with abnormal thyroid function composed Group 1, 58 patients who had normal thyroid function for at least 3 months composed Group 2, and 50 healthy individuals composed Group 3. Demographic data, neutrophil-to-lymphocyte ratio (NLR), monocyte-to-lymphocyte ratio (MLR), platelet-to-lymphocyte ratio (PLR), mean platelet volume (MPV), and systemic immune-inflammatory index (SII) were evaluated.

RESULTS

There was no statistically significant difference between groups in terms of age, sex, and smoking habits (p > 0.05). There was a statistically significant difference in NLR (p = 0.011), MLR (p = 0.013), MPV (p < 0.001), and SII (p < 0.001) values among 3 groups. For NLR, MLR, and SII the highest values were detected in Group 1. MPV levels were higher in Group 3 than Groups 1 and 2 (p < 0.001). None of the hematological parameters were found to be a risk factor for any clinical severity findings of GO.

CONCLUSION

The higher levels of NLR, MLR, and SII levels may show systemic inflammation in GO patients with abnormal thyroid function, and this may have an impact on the clinical course of ophthalmopathy. These findings may suggest that cautious control of thyroid hormone levels is important in the management of GO.

Prostaglandin F2α Regulates Adipogenesis by Modulating Extracellular Signal-Regulated Kinase Signaling in Graves' Ophthalmopathy

Prostaglandin F2α (PGF2α), the first-line anti-glaucoma medication, can cause the deepening of the upper eyelid sulcus due to orbital lipoatrophy. However, the pathogenesis of Graves' ophthalmopathy (GO) involves the excessive adipogenesis of the orbital tissues. The present study aimed to determine the therapeutic effects and underlying mechanisms of PGF2α on adipocyte differentiation. In this study primary cultures of orbital fibroblasts (OFs) from six patients with GO were established. Immunohistochemistry, immunofluorescence, and Western blotting (WB) were used to evaluated the expression of the F-prostanoid receptor (FPR) in the orbital adipose tissues and the OFs of GO patients. The OFs were induced to differentiate into adipocytes and treated with different incubation times and concentrations of PGF2α. The results of Oil red O staining showed that the number and size of the lipid droplets decreased with increasing concentrations of PGF2α and the reverse transcription-polymerase chain reaction (RT-PCR) and WB of the peroxisome proliferator-activated receptor γ (PPARγ) and fatty-acid-binding protein 4 (FABP4), both adipogenic markers, were significantly downregulated via PGF2α treatment. Additionally, we found the adipogenesis induction of OFs promoted ERK phosphorylation, whereas PGF2α further induced ERK phosphorylation. We used Ebopiprant (FPR antagonist) to interfere with PGF2α binding to the FPR and U0126, an Extracellular Signal-Regulated Kinase (ERK) inhibitor, to inhibit ERK phosphorylation. The results of Oil red O staining and expression of adipogenic markers showed that blocking the receptor binding or decreasing the phosphorylation state of the ERK both alleviate the inhibitory effect of PGF2a on the OFs adipogenesis. Overall, PGF2α mediated the inhibitory effect of the OFs adipogenesis through the hyperactivation of ERK phosphorylation via coupling with the FPR. Our study provides a further theoretical reference for the potential application of PGF2α in patients with GO.

Traditional Chinese medicine in thyroid-associated orbitopathy

PURPOSE

Orbital fibroblasts (OF) are considered the central target cells in the pathogenesis of thyroid-associated orbitopathy (TAO), which comprises orbital inflammation, orbital tissue edema, adipogenesis, fibrosis, oxidative stress and autophagy. Certain active ingredients of traditional Chinese medicine (TCM) demonstrated inhibition of TAO-OF in pre-clinical studies and they could be translated into novel therapeutic strategies.

METHODS

The pertinent and current literature of pre-clinical studies on TAO investigating the effects of active ingredients of TCM was reviewed using the NCBI PubMed database.

RESULTS

Eleven TCM compounds demonstrated inhibition of TAO-OF in-vitro and three of them (polydatin, curcumin, and gypenosides) resulted in improvement in TAO mouse models. Tanshinone IIA reduced inflammation, oxidative stress and adipogenesis. Both resveratrol and its precursor polydatin displayed anti-oxidative and anti-adipogenic properties. Celastrol inhibited inflammation and triptolide prevented TAO-OF activation, while icariin inhibited autophagy and adipogenesis. Astragaloside IV reduced inflammation via suppressing autophagy and inhibited fat accumulation as well as collagen deposition. Curcumin displayed multiple actions, including anti-inflammatory, anti-oxidative, anti-adipogenic, anti-fibrotic and anti-angiogenic effects via multiple signaling pathways. Gypenosides reduced inflammation, oxidative stress, tissue fibrosis, as well as oxidative stress mediated autophagy and apoptosis. Dihydroartemisinin inhibited OF proliferation, inflammation, hyaluronan (HA) production, and fibrosis. Berberine attenuated inflammation, HA production, adipogenesis, and fibrosis.

CONCLUSIONS

Clinical trials of different phases with adequate power and sound methodology will be warranted to evaluate the appropriate dosage, safety and efficacy of these compounds in the management of TAO.

Novel Insight into Non-Genetic Risk Factors of Graves' Orbitopathy

An assessment of the risk of Graves' orbitopathy (GO) is an important challenge in Graves' disease (GD) management. The purpose of this study was to compare non-genetic parameters in GD patients with and without GO in order to find novel risk factors and to verify the factors already reported. A total number of 161 people, 70 with GO and 91 non-GO patients were included in this study. GO was confirmed to be associated with smoking, older age, higher TSH receptor antibodies (TRAb) and lower thyroglobulin antibody (TgAb) levels and hypercholesterolemia. We demonstrated the latter correlation even for only a mild increase in LDL cholesterol. Importantly, our study provides novel potential GO risk factors, including higher serum creatinine levels, higher MCV and lower PLT. If further confirmed, these new, simple and easily accessible potential GO markers may constitute valuable auxiliary markers in GO risk assessments. We additionally proved that in moderate to severe GO, gender-related differences attenuate. No impact of vitamin D deficiency in GO development in patients with 25-hydroxyvitamin D [25(OH)D] > 20 ng/mL was found. The present report provides a set of GO risk factors, which can be used as a precise tool for an individual GO risk assessment.