IGF1 receptor and thyroid-associated ophthalmopathy

The Efficacy and Safety of Teprotumumab in Thyroid Eye Disease: Evidence from Randomized Controlled Trials

In this study, we conducted a meta-analysis to assess the efficacy and safety of teprotumumab in treating thyroid eye disease. We searched the Cochrane Library, PubMed, and Embase databases from inception to May 25, 2022, and included all randomized controlled trials. Odds ratios (ORs) were calculated using fixed- or random-effect models. A total of three studies involving 341 patients were identified. Overall, the analysis revealed that teprotumumab demonstrated superior integrated proptosis response compared to placebo in both the intention-to-treat (ITT) population (OR = 17.81, 95% CI = [10.32, 30.76], I2 = 50%) and per-protocol population (OR = 24.53, 95% CI = [12.96, 46.45], I2 = 14%). Furthermore, patients receiving teprotumumab showed significant improvement in overall response (OR = 8.35, 95% CI = [4.74, 14.71], I2 = 79%), diplopia response (OR = 5.53, 95% CI = [3.24, 9.44], I2 = 0%), and achieving a clinical activity score (CAS) of 0 or 1 (OR = 6.26, 95% CI = [3.87, 10.12], I2 = 0%). Moreover, patients treated with teprotumumab experienced greater improvements in proptosis (MD = -2.49, 95% CI = [-2.54, -2.45], I2 = 98%) and Graves' ophthalmopathy-specific quality of life (GO-QOL, MD = 11.48, 95% CI = [11.03, 11.93], I2 = 95%). However, it is important to note that patients receiving teprotumumab had a higher risk of adverse events, including serious adverse events, gastrointestinal adverse reactions, and muscle spasms. In summary, teprotumumab demonstrated greater improvement in proptosis response, proptosis, diplopia response, overall response, GO-QOL, and CAS. Nonetheless, it should be considered that its use is associated with a higher risk of adverse events.

Monoclonal Antibodies for the Treatment of Graves Orbitopathy: Precision Medicine?

PURPOSE

To summarize the development, nomenclature, and rationale of the reported use of monoclonal antibodies (Mabs) in Graves Orbitopathy (GO) and to undertake a systematic review of the management of GO with Mabs.

METHODS

The Pubmed and Embase databases and the Federal Brazilian searching site (Periódicos-CAPES) were screened. The authors searched all the keywords "monoclonal antibodies," "adalimumab," "belimumab," "infliximab," "rituximab," "teprotumumab," and "tocilizumab" combined with the terms "Graves Orbitopathy," "Graves eye disease" and "thyroid eye disease." All the articles published in English, French, and Spanish from 2000 to May 2022 were screened. Only publications with quantitative data on the activity of orbitopathy, proptosis, or both were included.

RESULTS

Seventy-six articles of the 954 screened records met the inclusion criteria. Seven Mabs were described for treating GO. The three most reported Mabs were Rituximab, Tocilizumab, and Teprotumumab. Only eight randomized clinical trials compared the effect of these three Mabs and Belimumab with the effect of steroids or placebos. Adalimumab, Infliximab, and K1-70 only appeared in a few case series and case reports. Frequent mild-to-moderate and few major side effects occurred with the three most used Mabs. Relapse rates ranged from 7.4% for Tocilizumab to at least 29.4% for Teprotumumab. No randomized clinical trials compared Mabs head-to-head.

CONCLUSION

Considering the lack of head-to-head comparisons between Mabs, the relapse rate, the possibility of severe collateral effects, and the cost of Mabs, it is not clear which Mab is the safest and most useful to treat GO.

Change in lacrimal gland volume and aqueous tear production following treatment with teprotumumab

BACKGROUND

Dry eye syndrome occurs in up to 85% of patients with thyroid eye disease (TED). Lacrimal gland enlargement correlates with subjective tearing and a reduction in quality of life in patients with TED.

METHODS

In this prospective longitudinal study, patients presenting for the treatment of TED were considered for eligible. Primary outcomes included a change in the volume of the lacrimal gland and the production of tears following treatment with teprotumumab. The volume of lacrimal glands and proptosis was calculated using 3D volumetric analysis. Tear production was measured by Schirmer's test and associated symptoms were assessed using the VLSQ-8. The orbit with the most proptosis was designated the study orbit and the contralateral orbit was designated the fellow orbit.

RESULTS

Twenty patients were included. Mean (SD) age was 61 (18) and mean duration of TED prior to therapy was 48 months (47). Lacrimal gland volume in the study orbit decreased from 768 mm³ (288) to 486 mm³ (173) (p < 0.01) following therapy. For the fellow orbit, volume reduced from 637 mm³ (261) to 379 mm³ (147) (p < 0.01). Schirmer's test reading (STR) in the study orbit increased from 14.5 mm (8.2) to 23 mm (10) (p < 0.01) (59%) following treatment. In the fellow orbit, STR increased from 12.7 mm (7) to 21 mm (9) post therapy (69%) (p < 0.01). There was a significant improvement on all parts of the VLSQ-8.

CONCLUSION

Teprotumumab significantly reduces TED related expansion of the lacrimal gland, increases tear production, and improves dry eye symptoms.

Identification of optimal surgical plan for treatment of extraocular muscle damage in thyroid eye disease patients based on computational biomechanics

This study replicated the behavior of intraorbital tissue in patients with thyroid eye disease (TED) based on finite element analysis for general orbital decompression risk evaluation in thyroid eye disease patients. The orbit and intraorbital tissues of thyroid eye disease patients who underwent orbital decompression were modeled as finite element models. The stress was examined at specific locations of the removed orbital wall of a thyroid eye disease patient with undergone orbital decompression, and its variation was analyzed as a function of the shape and dimension (to be removed). As a result, in orbital decompression surgery which removes the orbital wall in a rectangular shape, the stress at the orbital wall decreased as the width and depth of the removed orbital wall increased. In addition, in the case of orbital decompression, it can be seen that the chamfered model compared to the non-chamfered model (a form of general orbital decompression) have the stress reduction rate from 11.08% to 97.88%. It is inferred that if orbital decompression surgery considering the chamfered model is performed on an actual thyroid eye disease patient, it is expected that the damage to the extraocular muscle caused by the removed orbital wall will be reduced.

A review of TSHR- and IGF-1R-related pathogenesis and treatment of Graves' orbitopathy

Graves' orbitopathy (GO) is an organ-specific autoimmune disease, but its pathogenesis remains unclear. There are few review articles on GO research from the perspective of target cells and target antigens. A systematic search of PubMed was performed, focusing mainly on studies published after 2015 that involve the role of target cells, orbital fibroblasts (OFs) and orbital adipocytes (OAs), target antigens, thyrotropin receptor (TSHR) and insulin-like growth factor-1 receptor (IGF-1R), and their corresponding antibodies, TSHR antibodies (TRAbs) and IGF-1R antibodies (IGF-1R Abs), in GO pathogenesis and the potentially effective therapies that target TSHR and IGF-1R. Based on the results, OFs may be derived from bone marrow-derived CD34+ fibrocytes. In addition to CD34+ OFs, CD34- OFs are important in the pathogenesis of GO and may be involved in hyaluronan formation. CD34- OFs expressing Slit2 suppress the phenotype of CD34+ OFs. β-arrestin 1 can be involved in TSHR/IGF-1R crosstalk as a scaffold. Research on TRAbs has gradually shifted to TSAbs, TBAbs and the titre of TRAbs. However, the existence and role of IGF-1R Abs are still unknown and deserve further study. Basic and clinical trials of TSHR-inhibiting therapies are increasing, and TSHR is an expected therapeutic target. Teprotumumab has become the latest second-line treatment for GO. This review aims to effectively describe the pathogenesis of GO from the perspective of target cells and target antigens and provide ideas for its fundamental treatment.

Integrative metabolic analysis of orbital adipose/connective tissue in patients with thyroid-associated ophthalmopathy

Objective

Thyroid-associated ophthalmopathy (TAO) is a disfiguring autoimmune disease, which destroys the structure of orbital tissues and even threatens vision. Metabolic reprograming is critical in autoimmune diseases; however, the metabolic basis of TAO remains to be clarified. Our study aimed to reveal the metabolic profile of TAO.

Methods

Orbital adipose/connective tissues from eleven TAO patients and twelve control subjects were collected during surgeries and analyzed with liquid chromatograph-mass spectrometer. Orthogonal partial least-squares discrimination analysis (OPLS-DA), variable importance in projection (VIP), heat map, and volcano plot were used to reveal metabolic profile in TAO. Pathway analysis and metabolites-gene analysis were utilized to explore potential metabolic metabolism in TAO.

Results

3038 metabolites were detected in samples from the TAO patients and the controls. OPLS-DA analysis of the metabolomics results showed two distinguished groups, demonstrating that TAO has a unique metabolome. Univariate tests identified 593 dysregulated metabolites (P < 0.05), including 367 increased metabolites and 226 decreased metabolites. Pathway analysis showed that changed metabolites were enriched in cholesterol metabolism, choline metabolism in cancer, fat digestion and absorption, regulation of lipolysis in adipocytes, and insulin resistance. In addition, metabolites-gene analysis illustrated that cholesterol metabolism was involved in the pathogenesis of TAO. Endoplasmic reticulum stress-related genes (ATF6, PERK, and IRE1α) expressions were higher in TAO orbital tissues than in control orbital tissues verified by western blot. Additionally, the expression level of diacylglycerol acyltransferase 1 (DGAT1), a key metabolic protein for triacylglycerol synthesis, was increased in orbital tissues of TAO detected by qRT-PCR, indicating disrupted cholesterol metabolism in TAO.

Conclusion

The present study demonstrated different metabolite profiles and potential metabolic mechanisms in TAO.

Cytokines in Thyroid-Associated Ophthalmopathy

Thyroid-associated ophthalmopathy (TAO), also known as thyroid eye disease (TED) or Graves' orbitopathy (GO), is a complex autoimmune condition causing visual impairment, disfigurement, and harm to patients' physical and mental health. The pathogenesis of TAO has not been fully elucidated, and the mainstream view is that coantigens shared by the thyroid and orbit trigger remodeling of extraocular muscles and orbital connective tissues through an inflammatory response. In recent years, cytokines and the immune responses they mediate have been crucial in disease progression, and currently, common evidence has shown that drugs targeting cytokines, such as tocilizumab, infliximab, and adalimumab, may be novel targets for therapy. In this review, we summarize the research development of different cytokines in TAO pathogenesis in the hope of discovering new therapeutic targets.

Tears as a Source of Biomarkers in the Diagnosis of Graves' Orbitopathy

Thyroid eye disease (TED) is a poorly understood autoimmune manifestation of thyroid diseases most commonly associated with Graves' disease. Due to a lack of specific biomarkers and uncertain signs and symptoms, Graves' orbitopathy (GO) is challenging to diagnose early and treat effectively. Nowadays, there is great interest in searching for precise molecular biomarkers for early detection, disease monitoring, and clinical management. Researchers are keen to identify novel methods to predict and diagnose diseases and to monitor patient therapeutic response. Tears, due to their direct contact with the eye and the fact that lacrimal glands can also be affected by the disease, could give new insights into the mechanisms taking place in thyroid-associated orbitopathy (TAO) and reveal potential promising biomarkers. Tear fluid offers the possibility of the non-invasive acquisition of a sample with a high protein content, thereby attracting continuously growing interest in the discovery of novel biomarkers. This article provides an up-to-date overview of the various putative tear-fluid biomarkers that have been identified. In this review, we present the potential use of tears as a diagnostic fluid and tool to investigate the mechanism of ocular diseases and discuss the future research directions in this area.

Bone marrow fibrocytes: villain or white knight in thyroid-associated ophthalmopathy?

PURPOSE OF REVIEW

We attempt to provide an historical perspective on progress made in understanding the pathogenesis of thyroid-associated ophthalmopathy (TAO), focusing on the roles of orbital fibroblasts (OF) in the diseased orbit (termed GD-OF) and how these cells differ from those residing in the healthy orbit. GD-OF comprise both residential OF and those apparently derived from CD34 + fibrocytes.

RECENT FINDINGS

CD34 + fibrocytes of the monocyte lineage putatively traffic to the TAO orbit from bone marrow. We believe that these fibroblastic cell populations dictate the activity and severity of TAO. Their impact on disease may be moderated by Slit2, a neuron axon guidance repellent synthesized by and released from residential CD34 - OF. Approximately 50% of patients with GD develop clinically meaningful TAO. Relatively few require systemic medical and surgical therapies, while milder disease can be managed with conservative, local care. Determining the intrinsic properties of GD-OF and their expression of Slit2 may explain why some patients with GD develop severe, vision-threatening TAO while others virtually escape any of its manifestations. Such insights should allow for improved and better-tolerated therapies.

SUMMARY

Identifying unique characteristics of fibrocytes and GD-OF subsets reveals their apparent roles in tissue activation, inflammation, and remodeling associated with TAO. Better understanding of these cells, their origins, behavior, and factors modulating their activities remains necessary for the development of more targeted, effective, and safe treatments.

Thinking inside the box: Current insights into targeting orbital tissue remodeling and inflammation in thyroid eye disease

Thyroid eye disease (TED) is an autoimmune disorder that manifests in the orbit. In TED, the connective tissue behind the eye becomes inflamed and remodels with increased fat accumulation and/or increased muscle and scar tissue. As orbital tissue expands, patients develop edema, exophthalmos, diplopia, and optic neuropathy. In severe cases vision loss may occur secondary to corneal scarring from exposure or optic nerve compression. Currently there is no cure for TED, and treatments are limited. A major breakthrough in TED therapy occurred with the FDA approval of teprotumumab, a monoclonal insulin-like growth factor 1 receptor (IGF1R) blocking antibody. Yet, teprotumumab therapy has limitations, including cost, infusion method of drug delivery, variable response, and relapse. We describe approaches to target orbital fibroblasts and the complex pathophysiology that underlies tissue remodeling and inflammation driving TED. Further advances in the elucidation of the mechanisms of TED may lead to prophylaxis based upon early biomarkers as well as lead to more convenient, less expensive therapies.

MiR-143 Targets IGF-1R to Suppress Autoimmunity in Thyroid-Associated Ophthalmopathy

Objective

Thyroid-associated ophthalmopathy (TAO) is an autoimmune disease that involves the remodeling of orbit and periorbital tissues. Thyroid-stimulating hormone receptor (TSHR) and insulin-like growth factor 1 receptor (IGF-1R) may stimulate the activation of autoimmunity in TAO, but the exact mechanism is unclear. We investigated whether IGF-1R/TSHR modulation in TAO may involve microRNA regulation.

Methods

We conducted microarray analysis using RNA from the orbital connective tissue samples of 3 healthy and 3 patients with TAO. The involvement of differentially regulated microRNA in IGF-1R/TSHR modulation in TAO was evaluated in orbital fibroblasts (OFs) and female BALB/c mice.

Results

Using hierarchical cluster analysis, we identified that miR-143 was downregulated in TAO. The expression levels of miR-143 in OFs were significantly reduced under IL-1B stimulation. However, OF proliferation and inflammatory responses decreased when miR-143 is overexpressed. In contrast, the suppression of miR-143 increased levels of inflammatory markers (IL-6, IL-8, MCP1) and hyaluronan accumulation. Moreover, overexpression of miR-143 significantly lowers levels of IGF-1R and TSHR. A luciferase assay indicated that miR-143 targets the 3′-UTR of IGF-1R. Increases in the expression of IGF-1R increased the expression of the inflammasome marker NLRP3 and apoptotic marker cleaved caspase-1; however, miR-143 overexpression decreased levels of IGF-1R, TSHR, NLRP3, cleaved caspase 1, IL-1B, and IL-18. In a mouse model of TAO, overexpression of miR-143 significantly reduced levels of IGF-1R and attenuated the adipogenesis associated with TAO.

Conclusion

We found that miR-143 directly targets IGF-1R to alleviate the inflammatory response in TAO by indirectly decreasing levels of TSHR and inactivating NLRP3.

Teprotumumab (Tepezza) for Thyroid Eye Disease

Thyroid eye disease (TED) is an immune mediated infiltration and inflammation of the orbital and periorbital soft tissues leading to facial disfigurement. Classically broken into two "phases," active inflammatory and quiescent, disease modifying therapy and surgical intervention are used to improve a number of clinical aspects of TED. Many medical modalities have been utilized to halt the inflammatory phase of the disease including steroids, orbital radiation, and targeted steroid-sparing chemotherapy. Teprotumumab is currently the only Federal Drug Administration approved therapy for the treatment of TED. Significant improvements in proptosis, diplopia and quality of life are noted following its 24-week course of therapy.

Therapeutic IGF-I receptor inhibition alters fibrocyte immune phenotype in thyroid-associated ophthalmopathy

Thyroid-associated ophthalmopathy (TAO) represents a disfiguring and potentially blinding autoimmune component of Graves' disease. It appears to be driven, at least in part, by autoantibodies targeting the thyrotropin receptor (TSHR)/insulin-like growth factor I receptor (IGF-IR) complex. Actions mediated through either TSHR or IGF-IR are dependent on IGF-IR activity. CD34⁺ fibrocytes, monocyte lineage cells, reside uniquely in the TAO orbit, where they masquerade as CD34⁺ orbital fibroblasts. Fibrocytes present antigens to T cells through their display of the major histocompatibility complex class II (MHC II) while providing costimulation through B7 proteins (CD80, CD86, and programmed death-ligand 1 [PD-L1]). Here, we demonstrate that teprotumumab, an anti-IGF-IR inhibitor, attenuates constitutive expression and induction by the thyroid-stimulating hormone of MHC II and these B7 members in CD34⁺ fibrocytes. These actions are mediated through reduction of respective gene transcriptional activity. Other IGF-IR inhibitors (1H7 and linsitinib) and knocking down IGF-IR gene expression had similar effects. Interrogation of circulating fibrocytes collected from patients with TAO, prior to and following teprotumumab treatment in vivo during a phase 2 clinical trial, demonstrated reductions in cell-surface MHC II and B7 proteins similar to those found following IGF-IR inhibitor treatment in vitro. Teprotumumab therapy reduces levels of interferon-γ and IL-17A expression in circulating CD4⁺ T cells, effects that may be indirect and mediated through actions of the drug on fibrocytes. Teprotumumab was approved by the US Food and Drug Administration for TAO. Our current findings identify potential mechanisms through which teprotumumab might be eliciting its clinical response systemically in patients with TAO, potentially by restoring immune tolerance.

Teprotumumab in Clinical Practice: Recommendations and Considerations From the OPTIC Trial Investigators

BACKGROUND

Thyroid eye disease (TED) is a vision-threatening and debilitating condition that until very recently had no Food and Drug Administration (FDA)-approved medical therapies. Teprotumumab has recently been approved to treat TED. We aim to provide guidance for its use, based on the input of the US investigators who participated in Phase 2 and Phase 3 clinical trials.

METHODS

An expert panel was convened on October 11th and November 16th of 2019. All panel members had extensive experience as investigators in the Phase 2 and/or Phase 3 clinical trials of teprotumumab. Consensus among those investigators was reached to determine patient characteristics most appropriate for teprotumumab treatment. Safety guidelines were also reviewed and agreed on.

RESULTS

The authors recommend that teprotumumab be considered first-line therapy for patients with clinically significant ophthalmopathy, including those with disease duration exceeding 9 months. The clinical activity score (CAS) may be useful for longitudinal monitoring but should not be used to determine treatment eligibility. Criteria will likely be expanded after more experience with the drug. Using teprotumumab for patients with TED with substantial signs, symptoms, or morbidity without a CAS score of >4 (e.g., progressive proptosis, diplopia, and early compressive optic neuropathy) or more, could be considered. Diabetes mellitus and inflammatory bowel disease comorbidities should not be exclusionary, but stringent monitoring in these patients is recommended. Drug dosing, administration interval, and duration should adhere to the study protocol: 8 infusions, separated by 3 weeks. Patients with more severe disease may benefit from additional doses. Corticosteroids can be used before or during teprotumumab therapy. Clinical and laboratory monitoring should be consistent with good clinical practice for patients receiving teprotumumab.

CONCLUSIONS

Confirming the efficacy of teprotumumab usage outside the narrow parameters of the completed clinical trials will require rigorous scientific validation. As a step in that direction, we believe its on-label usage is appropriately applied to all patients with TED with substantial symptoms or morbidity, as judged by their physician.

The risk factors for Graves' ophthalmopathy

PURPOSE

This review aimed to provide an overview of current research into the risk factors for Graves' ophthalmopathy (GO).

METHODS

To find information about the risk factors for GO, the research database PubMed was searched and relevant articles were obtained to extract information about risk factors.

RESULTS

Smoking has been widely accepted as an important risk factor and cigarette smoking cessation has been shown to improve the outcome and decrease the onset of GO. Radioactive iodine on the thyroid may induce hyperthyroidism and increase the occurrence of GO. Selenium deficiency is a risk factor for GO and the supplementation of selenium has been an adjuvant therapy. Decreasing stressful life events (SLE) may help improve GO. Imbalance in intestinal flora is essential to GO, with Yersinia enterocolitica and Escherichia coli both increased in the digestive tract of the individual with GO. In addition, controlling serum cholesterol may help improve GO since adipogenesis is an important pathological change in its pathogenesis. Considering the correlation between Graves' disease and GO, maintaining normal thyroid function hormone level is the first-line therapeutic strategy to prevent progression of GO. An increase in antibodies such as TSHR and IGF-1R is the main predictor of GO. Besides, gender and gene polymorphism are also risk factors towards GO.

CONCLUSIONS

Risk factors for GO arise from five sources: physical and chemical environment, social-psychological environment, biological environment, the human organism, and genetic codes. Risk factors within these categories may interact with each other and their mechanisms in promoting the development of GO are complex. Research into risk factors for GO may promote emerging fields related to GO such as control of autoantibodies and intestinal microbiota.

Diagnostic accuracy of Immulite® TSI immunoassay for thyroid-associated orbitopathy in patients with recently diagnosed Graves' hyperthyroidism

PURPOSE

The Immulite® thyroid stimulating immunoglobulin (TSI) immunoassay is a relatively new commercial assay that has shown good diagnostic accuracy in Graves' hyperthyroidism (GH). However, its clinical utility in thyroid-associated orbitopathy (TAO) is less clear. The purpose of this study was to assess the diagnostic accuracy of the Immulite® TSI immunoassay for TAO and investigate the associations between TSI and other clinical measures.

METHODS

One hundred and forty patients that had been diagnosed with GH within the previous 12 months were recruited. Identification and grading of TAO were performed at enrolment and serum samples were analysed using the Immulite® TSI immunoassay.

RESULTS

Of the 140 participants recruited, 75 (53.6%) had TAO. Age, sex and time since GH diagnosis were similar between those with and without TAO (p ≥ 0.300). TSI level tended to decrease with increasing time from GH diagnosis (Spearman's ρ - 0.28, 95% CI - 0.43, - 0.12). TSI levels were higher among those with than those without TAO (median 4.0 vs. 2.7 IU/L, respectively, p = 0.037). There was no correlation between TSI level and inflammatory index score (ρ = 0.14, 95% CI - 0.03, 0.30) or clinical severity (p = 0.527) among those with TAO. TSI level showed poor diagnostic accuracy for TAO (area under the receiver operating characteristic curve 0.60, 95% CI 0.51, 0.70).

CONCLUSIONS

Although Immulite® TSI level was higher in the presence of TAO, it showed poor diagnostic accuracy and no correlation with clinical markers of TAO severity or activity.

[Monoclonal antibodies in the treatment of thyroid eye disease]

Thyroid eye disease (TED) is an autoimmune condition affecting extraocular muscles and orbital fat that is most often a manifestation of the Graves' disease or Hashimoto thyroiditis. This disease significantly worsens the quality of life of patients, and therefore requires the use of effective treatment methods. Traditional therapy involves glucocorticosteroids and x-rays aimed at reducing the inflammatory process, rather than proptosis and diplopia, while targeted therapy is better able to influence the clinical course of the disease. The review presents a modern understanding of the pathogenesis of TED and analysis of clinical studies concerning the use of monoclonal antibodies for its treatment.

Thyroid-related ophthalmopathy development in concurrence with growth hormone administration

BACKGROUND

Thyroid stimulating hormone (TSH) receptor and local infiltrate lymphocytes have been considered as major pathological factors for developing thyroid-related ophthalmopathy. Overexpression of insulin-like growth factor-I (IGF-I) receptor has emerged as a promising therapeutic target for refractory patients. However, the relationship between activation of growth hormone (GH)/IGF-I receptor signaling and development or exacerbation of thyroid ophthalmopathy has not been elucidated. Herein we describe a case that provides further clarification into the association between thyroid-related ophthalmopathy and GH/IGF-I receptor signaling.

CASE PRESENTATION

A 62-year-old Japanese female diagnosed with thyroid-related ophthalmopathy was admitted to Kurume University Hospital. She had received daily administration of GH subcutaneously for severe GH deficiency; however, serum IGF-I levels were greater than + 2 standard deviation based on her age and sex. She exhibited mild thyrotoxicosis and elevation in levels of TSH-stimulating antibody. Discontinuation of GH administration attenuated the clinical activity scores of her thyroid-related ophthalmopathy. Additionally, concomitant use of glucocorticoid and radiation therapies resulted in further improvement of thyroid-related ophthalmopathy. The glucocorticoid administration was reduced sequentially, followed by successful termination. Thereafter, the patient did not undergo recurrence of thyroid-related ophthalmopathy and maintained serum IGF-I levels within normal physiological levels.

CONCLUSIONS

We describe here a case in which development of thyroid-related ophthalmopathy occurred upon initiation of GH administration. GH/IGF-I signaling was highlighted as a risk factor of developing thyroid-related ophthalmopathy. Additionally, aberrant TSH receptor expression was suggested to be a primary pathophysiological mechanism within the development of thyroid-related ophthalmopathy. Physicians should be aware of the risks incurred via GH administration, especially for patients of advanced age, for induction of thyroid-related ophthalmopathy.

Teprotumumab: Interpreting the Clinical Trials in the Context of Thyroid Eye Disease Pathogenesis and Current Therapies

Teprotumumab, a monoclonal antibody targeted against the insulin-like growth factor 1 (IGF-1) receptor, was recently approved by the United States Food and Drug Administration for the treatment of thyroid eye disease (TED). Phase 1 studies of teprotumumab for the treatment of malignancies demonstrated an acceptable safety profile but limited effectiveness. Basic research implicating the IGF-1 receptor on the CD-34+ orbital fibrocyte in the pathogenesis of TED renewed interest in the drug. Two multicenter, randomized, double-masked, clinical trials (phase 2 and 3) evaluated the efficacy of 8 infusions of teprotumumab every 3 weeks versus placebo in 170 patients with recent-onset active TED, as defined by a clinical activity score (CAS) of at least 4. Teprotumumab was superior to placebo for the primary efficacy end points in both studies: overall responder rate as defined by a reduction of 2 or more CAS points and a reduction of 2 mm or more in proptosis (69% vs. 20%; P < 0.001; phase 2 study) and proptosis responder rate as defined by a reduction of 2 mm or more in proptosis (83% vs. 10%; P < 0.001; phase 3 study). In both studies, treatment with teprotumumab compared with placebo achieved a significant mean reduction of proptosis (-3.0 mm vs. -0.3 mm, phase 2 study; -3.32 mm vs. -0.53 mm, phase 3 study) and CAS (-4.0 vs. -2.5, phase 2 study; -3.7 vs. -2.0, phase 3 study). Teprotumumab also resulted in a greater proportion of patients with a final CAS of 0 or 1, higher diplopia responder rate, and a larger improvement in the Graves' Ophthalmopathy Quality of Life overall score. More than half of patients (62%, phase 2 trial; 56%, phase 3 trial) who were primary end point responders maintained this response at 51 weeks after the last dose of therapy. The most common adverse events reported with teprotumumab included muscle spasms (25%), nausea (17%), alopecia (13%), diarrhea (13%), fatigue (10%), hearing impairment (10%), and hyperglycemia (8%). Teprotumumab is contraindicated for those with inflammatory bowel disease and who are pregnant. Although the current dosing regimen has proven effective for TED, dose-ranging studies including variable concentrations, infusion frequencies, and durations of teprotumumab therapy in the setting of TED have not been performed.

Association of thyroid autoimmunity and the response to recombinant human growth hormone in Turner syndrome

OBJECTIVES

Short stature and thyroid autoimmunity are common comorbidities in Turner syndrome (TS). Recombinant human growth hormone (rhGH) significantly improves height growth in TS individuals. This study aims to investigate the association of thyroid autoimmunity and the response to rhGH treatment in TS patients.

METHODS

Medical records of 494 patients with TS were reviewed. Among 126 patients who regularly tested for thyroid autoantibodies, 108 patients had received rhGH treatment. Clinical characteristics, including karyotype and the presence of autoimmune thyroid diseases, as well as rhGH treatment records were analyzed. Height velocity (HV) of patients with or without thyroid autoimmunity was compared to assess the response to rhGH treatment. For patients who developed thyroid autoantibodies during rhGH treatment, HV before and after antibody presence were compared.

RESULTS

45XO monosomy presented in 36% (176/496) of patients. 42.1% of patients (53/126) had elevated circulating anti-thyroid peroxidase antibody and anti-thyroglobulin antibody. In 108 patients who received rhGH treatment, HVs were significantly correlated to age, height, weight and BMI at the initiation of treatment. For patients who developed thyroid autoantibodies during rhGH treatment, HVs after thyroid autoantibody presence significantly decreased compared with HVs before thyroid autoantibody detection (n=44, p=0.0017).

CONCLUSIONS

Our data suggested that in TS patients who developed thyroid autoantibodies during rhGH treatment, the response to rhGH is negatively associated with the development of thyroid autoimmunity.

Genetic Profiling of Orbital Fibroblasts from Patients with Graves' Orbitopathy

CONTEXT

Graves' orbitopathy (GO) is an autoimmune disease that persists when immunosuppression is achieved. Orbital fibroblasts from GO patients display peculiar phenotypes even if not exposed to autoimmunity, possibly reflecting genetic or epigenetic mechanisms, which we investigated here.

OBJECTIVE

We aimed to explore potential genetic or epigenetic differences using primary cultures of orbital fibroblasts from GO and control patients.

METHODS

Cell proliferation, hyaluronic acid (HA) secretion, and HA synthases (HAS) were measured. Next-generation sequencing and gene expression analysis of the whole genome were performed, as well as real-time-PCR of selected genes and global DNA methylation assay on orbital fibroblasts from 6 patients with GO and 6 control patients from a referral center.

RESULTS

Cell proliferation was higher in GO than in control fibroblasts. Likewise, HA in the cell medium was higher in GO fibroblasts. HAS-1 and HAS-2 did not differ between GO and control fibroblasts, whereas HAS-3 was more expressed in GO fibroblasts. No relevant gene variants were detected by whole-genome sequencing. However, 58 genes were found to be differentially expressed in GO compared with control fibroblasts, and RT-PCR confirmed the findings in 10 selected genes. We postulated that the differential gene expression was related to an epigenetic mechanism, reflecting diverse DNA methylation, which we therefore measured. In support of our hypothesis, global DNA methylation was significantly higher in GO fibroblasts.

CONCLUSIONS

We propose that, following an autoimmune insult, DNA methylation elicits differential gene expression and sustains the maintenance of GO.

Ocular surface changes in Graves' ophthalmopathy

Many patients with Graves' ophthalmopathy (GO) suffer from dry eye syndrome (DES), and this is one of the most common reasons of eye discomfort in patients with GO. The prevalence of DES in patients with GO is significantly higher than normal subjects. The ocular surface changes involving changes in tears, cornea, conjunctiva and glands occur in GO patients. However, the mechanism of how DES occurs in GO still remains unclear. In this review, the ocular surface changes were illustrated and analyzed the reasons for high prevalence of DES in GO patients.

A data-driven approach for the discovery of biomarkers associated with thyroid eye disease

Background

Thyroid eye disease (TED) is the most common autoimmune disease and usually occurs in patients with hyperthyroidism. In this disease, eye-related tissue, such as eye muscles, eyelids, tear glands, etc., become inflated, which causes the eyes and eyelids to become red, swollen, and uncomfortable. The pathophysiology of this disease is still poorly known.

Aim

This study aims to discover potential biomarkers and regulatory pathways of TED which will not only help to diagnose the disease and understand orbital involvement in thyroid dysfunction but also provide an insight for better therapeutics.

Methods

We applied a data-driven approach by combining gene biomarkers both from published literature and computationally predicted from microarray gene expression data. Further, the DAVID tool is used for Gene Ontology-based enrichment analysis.

Results

We obtained a total of 22 gene biomarkers, including 18 semi-automatically curated from the literature and 4 predicted using data-driven approaches, involved in the pathogenesis of TED that can be used as potential information for therapeutic targets. Further, we constructed a regulatory pathway of TED biomarkers comprises of 310 connected components, and 1134 interactions using four prominent interaction databases.

Conclusion

This constructed pathway can be further utilized for disease dynamics and simulation studies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12886-021-01903-9.

Teprotumumab: The Dawn of Therapies in Moderate-to-Severe Thyroid-Associated Ophthalmopathy

Thyroid-associated ophthalmopathy (TAO) is a potentially sight-threatening ocular disease. About 3-5% of patients with TAO have severe disease with intense pain, inflammation, and sight-threatening corneal ulceration or compressive optic neuropathy. The current treatments of TAO are often suboptimal, mainly because the existing therapies do not target the pathogenesis of the disease. TAO mechanism is unclear. Ocular fibrocytes express relatively high levels of the functional TSH receptor (TSHR), and many indirect evidences support its participation. Over expression of insulin-like growth factor-1 receptor (IGF-IR) in fibroblasts, leading to inappropriate expression of inflammatory factors, production of hyaluronic acid and cell activation in orbital fibroblasts are also possible mechanisms. IGF-1R and TSHR form a physical and functional signaling complex. Inhibition of IGF-IR activity leads to the attenuation of signaling initiated at either receptor. Teprotumumab (TMB) is a human immunoglobulin G1 monoclonal antibody, binding to IGF-IR. Recently two TMB clinical trials had been implemented in TAO patients, indicating dramatic reductions in disease activity and severity, which approved its use for the treatment of TAO in the US. This review summarizes the treatments of TAO, focusing on the pathogenesis of IGF-1R in TAO and its application prospects.

Lessons Learned from Targeting IGF-I Receptor in Thyroid-Associated Ophthalmopathy

Complex immunological mechanisms underlie the pathogenesis of thyroid-associated ophthalmopathy (TAO). Historical models of Graves’ disease and TAO have focused almost entirely on autoimmune reactivity directed against the thyrotropin receptor (TSHR). The insulin-like growth factor-I receptor (IGF-IR) has been proposed as a second participating antigen in TAO by virtue of its interactions with IGFs and anti-IGF-IR antibodies generated in Graves’ disease. Furthermore, the IGF-IR forms with TSHR a physical and functional complex which is involved in signaling downstream from both receptors. Inhibition of IGF-IR activity results in attenuation of signaling initiated at either receptor. Based on the aggregate of findings implicating IGF-IR in TAO, the receptor has become an attractive therapeutic target. Recently, teprotumumab, a human monoclonal antibody IGF-IR inhibitor was evaluated in two clinical trials of patients with moderate to severe, active TAO. Those studies revealed that teprotumumab was safe and highly effective in reducing disease activity and severity. Targeting IGF-IR with specific biologic agents may result in a paradigm shift in the therapy of TAO.

Thyroid eye disease: Redefining its management-A review

Thyroid eye disease (TED) is a debilitating, vision threatening disease that dramatically alters patients' quality of life. Until recently, the management of TED is a long arduous course with supportive therapy, followed by an extensive surgical treatment plan to reverse the disease endpoints. Teprotumumab offers an early, safe therapeutic intervention to help reverse disease end points such as diplopia and proptosis and improve quality of life.

Slit2 Regulates Hyaluronan & Cytokine Synthesis in Fibrocytes: Potential Relevance to Thyroid-Associated Ophthalmopathy

CONTEXT

CD34+ fibrocytes have been implicated in development of thyroid-associated ophthalmopathy (TAO), a consequential autoimmune manifestation of Graves disease (GD). In TAO, CD34+ fibrocytes appear to masquerade as CD34+ orbital fibroblasts mixed with CD34- OF (collectively, GD-OF). Slit2, an axon guidance glycoprotein, is expressed by CD34- OF and attenuates GD-OF gene expression. Cardinal features of TAO include hyaluronan (HA) accumulation and cytokine-driven inflammation.

OBJECTIVE

Compare expression of HA synthase isoenzymes (HAS1-3), UDP-glucose dehydrogenase (UGDH), synthesis of HA, interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) in fibrocytes and GD-OF. Determine whether Slit2 alters gene expression patterns.

DESIGN/SETTING/PARTICIPANTS

Patients with TAO and healthy donors were recruited from an academic practice.

MAIN OUTCOME MEASURES

Real-time polymerase chain reaction, HA, IL-6, and TNF-α immunoassays.

RESULTS

HA synthesis and release from fibrocytes is substantially lower than in GD-OF. HAS1 expression dominates in fibrocytes while HAS2 in GD-OF. In contrast, HAS2 and UGDH expression dominate GD-OF and localize to CD34- OF. Recombinant human Slit2 (rhSlit2) substantially upregulates HA synthesis and HAS2 expression in fibrocytes but attenuates IL-6 and TNF-α production in these cells. In contrast, knocking down Slit2 in GD-OF reduces HA synthesis and HAS2 and UGDH expression while upregulating IL-6 and TNF-α.

CONCLUSION

The dramatic differences in HA, IL-6, and TNF-α production, and HAS and UGDH expression found in fibrocytes and GD-OF appear, at least in part, to be attributable to Slit2. These findings provide novel insight into the differences in gene expression exhibited by CD34+ fibrocytes and CD34+ OF and therefore reveal important aspects of disease pathogenesis.

Cytokines as Targets of Novel Therapies for Graves' Ophthalmopathy

Graves' disease (GD) is an organ-specific autoimmune disorder of the thyroid, which is characterized by circulating TSH-receptor (TSH-R) stimulating antibodies (TSAb), leading to hyperthyroidism. Graves' ophthalmopathy (GO) is one of GD extra-thyroidal manifestations associated with the presence of TSAb, and insulin-like growth factor-1 receptor (IGF-1R) autoantibodies, that interact with orbital fibroblasts. Cytokines are elevated in autoimmune (i.e., IL-18, IL-6) and non-autoimmune hyperthyroidism (i.e., TNF-α, IL-8, IL-6), and this could be associated with the chronic effects of thyroid hormone increase. A prevalent Th1-immune response (not related to the hyperthyroidism per se, but to the autoimmune process) is reported in the immune-pathogenesis of GD and GO; Th1-chemokines (CXCL9, CXCL10, CXCL11) and the (C-X-C)R3 receptor are crucial in this process. In patients with active GO, corticosteroids, or intravenous immunoglobulins, decrease inflammation and orbital congestion, and are considered first-line therapies. The more deepened understanding of GO pathophysiology has led to different immune-modulant treatments. Cytokines, TSH-R, and IGF-1R (on the surface of B and T lymphocytes, and fibroblasts), and chemokines implicated in the autoimmune process, are possible targets of novel therapies. Drugs that target cytokines (etanercept, tocilizumab, infliximab, adalimumab) have been tested in GO, with encouraging results. The chimeric monoclonal antibody directed against CD20, RTX, reduces B lymphocytes, cytokines and the released autoantibodies. A multicenter, randomized, placebo-controlled, double-masked trial has investigated the human monoclonal blocking antibody directed against IGF-1R, teprotumumab, reporting its effectiveness in GO. In conclusion, large, controlled and randomized studies are needed to evaluate new possible targeted therapies for GO.

Putative protective role of autoantibodies against the insulin-like growth factor-1 receptor in Graves' Disease: results of a pilot study

BACKGROUND

The insulin-like growth factor-1 receptor (IGF-1R) is a key element in the pathogenesis of Graves' Orbitopathy (GO), but the role of IGF-1R autoantibodies (IGF-1RAbs) has not been established.

METHODS

We designed a cross-sectional investigation to measure IGF-1RAbs in patients with Graves' disease (GD), with or without GO, who underwent radioiodine therapy followed by glucocorticoids (GC). Twenty-nine patients were included, 15 of which with GO. Patients were evaluated at baseline and three and 6 months after radioiodine. The primary objective was the prevalence of positive tests for IGF-1RAbs. The secondary objectives were: (1) IGF-1RAbs concentrations and their variations; (2) relationship between IGF-1RAbs and the features of GO; (3) relationship between IGF-1RAbs and anti-thyroid autoantibodies.

RESULTS

IGF-1RAbs above the cut-off value were found only in one patient with GD without GO. IGF-1RAb levels were greater in patients with GD without GO, at baseline (P < 0.0001), and after three (P < 0.0001) and six (P = 0.0001) months. No correlations were observed between IGF-1RAbs and the features of GO, nor between IGF-1RAbs and anti-thyroglobulin or anti-thyroperoxidase autoantibodies. There was an inverse correlation between anti-TSH receptor autoantibodies (TRAbs) and IGF-1RAb levels in GD patients with GO at 6 months (P = 0.03).

CONCLUSIONS

IGF-1RAbs appear to be greater in patients with GD without GO compared with those with GO, suggesting a putative protective role of IGF-1RAbs on the development of GO, in line with the beneficial effects of Teprotumumab on GO. The inverse correlation between IGF-1RAbs and TRAbs 6 months after radioiodine may reflect antigen spreading and/or GC treatment.

Teprotumumab reduces extraocular muscle and orbital fat volume in thyroid eye disease

Purpose

Thyroid eye disease (TED) is a progressive, debilitating and potentially vision-threatening autoimmune disease. Teprotumumab, a novel human monoclonal antibody, has been shown to reverse the clinical manifestations of TED. Patients receiving teprotumumab have been shown in two multicenter, randomized placebo-controlled trials to have decreased proptosis, diplopia and inflammation after 24 weeks of treatment. This study aims to analyse volumetric and inflammatory changes on orbital imaging prior to and after teprotumumab treatment from one of these trials.

Design

Retrospective review.

Subjects

Six patients enrolled in the phase III teprotumumab clinical trial (OPTIC, NCT03298867) with active TED who received 24 weeks of teprotumumab and had pre- and post-treatment orbital imaging (CT or MRI). Additionally, 12 non-TED patients (24 orbits) were analysed as a comparative control group.

Methods

3D volumetric calculations of the extraocular muscles (EOMs), orbital fat, and bony orbit were measured using previously validated image processing software. 3D volumetric results and changes in EOM inflammation were compared with clinical measurements of TED.

Results

Total EOM volume within each orbit was markedly reduced post-teprotumumab in all patients (n=six patients, 12/12 orbits, p<0.02). There was no statistical difference in post-treatment EOM volume when compared to non-TED controls. Total orbital fat volume was also reduced in 11 of 12 studied orbits (n=six patients, p=0.04). Overall EOM inflammation based on MRI signal intensity ratio was reduced in 8/8 orbits (n=four patients, p<0.01).

Conclusion

Orbital imaging demonstrated decreased EOM volumes and orbital fat tissue volumes after teprotumumab treatment.

Functionally enhanced placenta-derived mesenchymal stem cells inhibit adipogenesis in orbital fibroblasts with Graves' ophthalmopathy

BACKGROUND

Placenta-derived mesenchymal stem cells (PD-MSCs) have unique immunomodulatory properties. Phosphatase of regenerating liver-1 (PRL-1) regulates the self-renewal ability of stem cells and promotes proliferation. Graves' ophthalmopathy (GO) is an autoimmune inflammatory disease of the orbit and is characterized by increased orbital levels of adipose tissue. Here, we evaluated the therapeutic mechanism for regulation of adipogenesis by PRL-1-overexpressing PD-MSCs (PD-MSCs^PRL-1, PRL-1+) in orbital fibroblast (OF) with GO patients.

METHODS

PD-MSCs isolated from human placenta were transfected with the PRL-1 gene using nonviral transfection method. Primary OFs were isolated from orbital adipose tissue specimens from GO patients. After maturation as adipogenic differentiation, normal and GO-derived OFs were cocultured with naïve and PD-MSCs^PRL-1. We analyzed the protein levels of adipogenesis markers and their signaling pathways in OFs from GO patients.

RESULTS

The characteristics of PD-MSCs^PRL-1 were similar to those of naïve cells. OFs from GO patients induced adipocyte differentiation and had significantly decreased a lipid accumulation after coculture with PD-MSCs^PRL-1 compared to naïve cells. The mRNA and protein expression of adipogenic markers was decreased in PD-MSCs^PRL-1. Insulin-like growth factor-binding proteins (IGFBPs) secreting PD-MSCs^PRL-1 downregulated the phosphorylated PI3K/AKT/mTOR expression in OFs from GO patients. Interestingly, IGFBP2, - 4, - 6, and - 7 expression in PD-MSCs^PRL-1, which was mediated by integrin alpha 4 (ITGA4) and beta 7 (ITGB7), was higher than that in naïve cells and upregulated phosphorylated FAK downstream factor.

CONCLUSION

In summary, IGFBPs secreting PD-MSC^PRL-1 inhibit adipogenesis in OFs from GO patients by upregulating phosphorylated FAK and downregulating PI3K/AKT/mTOR signaling pathway. The functional enhancement of PD-MSCs by nonviral gene modification provides a novel therapeutic strategy for the treatment of degenerative diseases.

Teprotumumab for the treatment of thyroid eye disease

INTRODUCTION

Thyroid eye disease is a debilitating, disfiguring, and potentially blinding periocular condition. Teprotumumab is a human insulin-like growth factor-I receptor monoclonal inhibitor antibody which indicated for treating thyroid eye disease.

AREAS COVERED

The authors performed a systematic review of the literature using the PubMed database, and the following keywords were used: 'teprotumumab,' 'thyroid eye disease,' and 'insulin-like growth factor I receptor.' The chemical property, mechanism of action, pharmacokinetics, clinical efficacy, and safety of teprotumumab were introduced in this paper.

EXPERT OPINION

Teprotumumab is a human monoclonal antibody targeting insulin-like growth factor-I receptor. Clinical trials indicated that proptosis response of teprotumumab was 83%, and clinical activity score, diplopia, and quality of life were also better than placebo. Teprotumumab was well tolerated, common adverse reactions included muscle spasm, nausea, alopecia, diarrhea, fatigue, hyperglycemia, hearing impairment, dysgeusia, headache, and dry skin.

Teprotumumab: a novel therapeutic monoclonal antibody for thyroid-associated ophthalmopathy

INTRODUCTION

Thyroid-associated ophthalmopathy (TAO) is a disfiguring, potentially blinding, and sub-optimally managed autoimmune condition. Current therapy of active TAO consists most frequently of glucocorticoid steroids, orbital radiation, or B-cell depletion; all of which are associated with substantial side effects. Teprotumumab (Tepezza) is a human monoclonal antibody against the insulin-like growth factor type I receptor (IGF-IR), recently evaluated in two clinical trials for active moderate-to-severe TAO that was recently approved by the United States Food and Drug Administration (FDA) for use in TAO.

AREAS COVERED

This article reviews phase II and III placebo-controlled, double-masked, prospective, multicenter studies assessing the efficacy and safety of teprotumumab for the treatment of active, moderate-to-severe TAO.

EXPERT OPINION

Teprotumumab has demonstrated substantial and rapid improvement in Clinical Activity Score and proptosis reduction in TAO compared to placebo. Subjective diplopia and quality of life were also improved in both clinical trials. Teprotumumab exhibited a favorable safety profile, with transient hyperglycemia, muscle cramps, and auditory side effects being associated with the drug; these were usually transient. The trial findings indicate that teprotumumab is a promising, potential first-line therapy for treating TAO.

TSH/IGF1 receptor crosstalk: Mechanism and clinical implications

Increasing evidence of interdependence between G protein-coupled receptors and receptor tyrosine kinase signaling pathways has prompted reevaluation of crosstalk between these receptors in disease and therapy. Investigations into thyroid-stimulating hormone (TSH) and insulin-like growth factor 1 (IGF1) receptor crosstalk, and its application to the clinic have in particular shown recent progress. In this review, we summarize current insights into the mechanism of TSH/IGF1 receptor crosstalk. We discuss evidence that crosstalk is one of the underlying causes of TSHR-based disease and the feasibility of using combinations of TSH receptor and IGF1 receptor antagonists to increase the therapeutic index for the treatment of Graves' hyperthyroidism and Graves' ophthalmopathy.

A New Era in the Treatment of Thyroid Eye Disease

PURPOSE

Improved understanding of thyroid eye disease (TED) pathogenesis has facilitated identification of a targeted molecular approach for TED treatment offering the potential to halt or slow disease progression in a nonsurgical manner. Herein, we provide a summary of the current knowledge of TED management, followed by discussion of a novel insulin-like growth factor-1 receptor (IGF-1R) antagonist antibody and its potential to change the course of the disease.

DESIGN

Perspective.

METHODS

Review of the literature and authors' experience.

RESULTS

Many publications demonstrate IGF-1R overexpression in TED, and its activation as an autoantigen as a critical factor in TED pathogenesis. Several in vitro studies demonstrate that IGF-1R inhibition attenuates downstream molecular events including cytokine and hyaluronan production, and cellular differentiation. These observations led to the hypothesis that blocking IGF-1R may abrogate the clinical progression of TED. The recent completion of phase 2 and 3 randomized, placebo-controlled trials demonstrate the efficacy and safety of teprotumumab, a fully human monoclonal IGF-1R antagonist antibody, in patients with moderate-to-severe, active TED. Both the phase 2 and the recent phase 3 study results demonstrate that more patients with active TED receiving teprotumumab experienced a meaningful improvement in proptosis.

CONCLUSIONS

Current TED treatment strategies target inflammation and symptoms, but do not modify the disease course. Therefore, proptosis as well as strabismus and its resulting diplopia often remain, impacting patient well-being and quality of life over the long term. Targeted molecular therapy using teprotumumab demonstrates disease-modifying benefits with the potential to shift the paradigm for TED treatment.

Thyroid Eye Disease: How A Novel Therapy May Change The Treatment Paradigm

Thyroid eye disease (TED) is a complex, debilitating autoimmune disease that causes orbital inflammation and tissue remodeling, resulting in proptosis, diplopia, and in severe cases, loss of vision. TED can lead to facial disfigurement and severely impact patients’ quality of life. Although the course of TED was identified over 60 years ago, effective treatment options have proved to be challenging. Current treatments such as glucocorticoid therapy and orbital radiation focus on reducing orbital inflammation. However, these therapies fail to modify the disease outcomes, including proptosis and diplopia. Recent advances in the understanding of the molecular basis of TED have facilitated the development of targeted molecular therapies such as teprotumumab, an insulin-like growth factor-1 receptor inhibiting monoclonal antibody. In recent phase 2 and phase 3 randomized placebo-controlled trials, teprotumumab rapidly achieved improvement in clinical endpoints defining TED, including improved proptosis and diplopia. Dramatic improvement in clinical outcomes achieved after teprotumumab therapy during active TED are heretofore singular and comparable only to surgical therapies achieved during the inactive phase of TED. The advent of effective medical therapy can lead to a paradigm shift in the clinical management of TED. This review will provide an overview of TED, its epidemiology, insight into the molecular biology of the disease, clinical characteristics and diagnosis, and current and emerging treatment modalities.

Immunotherapies for thyroid eye disease

PURPOSE OF REVIEW

Thyroid eye disease is a complex autoimmune disorder which causes substantial morbidity. It can result in orbital disfigurement, double vision, and visual loss. Consequently, it has a substantial negative effect on quality of life, mental health, and socioeconomic status. Most signs and symptoms of thyroid eye disease (TED) can be explained by the expansion of the orbital contents. Steroids are the mainstay of treatment in TED. However, recurrence may occur once steroids are withdrawn. Furthermore, in most cases, normal orbital anatomy is not restored, and skilled rehabilitative surgery is required to reduce disfigurement, double vision, and to preserve vision. Therefore, novel, causal, and more efficacious treatment strategies are warranted.

RECENT FINDINGS

In the last decade, the pathophysiology of TED has also been revised with the identification of new potential therapeutic targets. Recent clinical trials have shown that considerable benefit may be derived from the addition of antiproliferative agents (e.g., mycophenolate sodium) in preventing deterioration after steroid cessation. In addition, targeted biologic therapies have shown promise, including teprotumumab (anti-IGFR) which appears to substantially reduce proptosis, rituximab (anti-CD20) which reduces inflammation and tocilizumab (anti-IL-6) which potentially benefits both of these parameters.

SUMMARY

This short review summarizes the recent research developments in this area.

The role of cell mediated immunopathogenesis in thyroid-associated ophthalmopathy

Currently, thyroid-associated ophthalmopathy (TAO) lacks effective treatment due to our lack of clarity in its immunopathogenesis. Orbital fibroblasts play a key role in altering inflammation and immune response in TAO, and are considered as the key target and effector cells in its pathogenesis. The orbit infiltrating CD34+ fibrocytes add on to the process by expressing high levels of autoantigens and inflammatory cytokines, while also differentiating into myofibroblasts or adipocytes. This review focuses on the role of orbital fibroblasts and CD34+ fibrocytes in the pathogenesis of TAO, highlighting the basis of emerging treatments.

Serum antibodies against the insulin-like growth factor-1 receptor (IGF-1R) in Graves' disease and Graves' orbitopathy

BACKGROUND

A role of the insulin-like growth factor-1 receptor (IGF-1R) in the pathogenesis of Graves' orbitopathy (GO) has been proposed, but the existence and function of anti-IGF-1R-antibodies (IGF-1R-Abs) are debated.

METHODS

We designed a cross-sectional investigation to measure serum IGF-1R-Abs by a commercial assay in consecutive patients with Graves' disease (GD) compared with healthy subjects and patients with autoimmune thyroiditis (AT). A total of 134 subjects were screened including 27 healthy subjects, 80 GD patients (54 of whom with GO), and 27 AT patients. The main outcome measure was the prevalence of positive serum IGF-1R-Abs in GO, compared with GD without GO and with the other study groups.

RESULTS

Having established a cut-off value at 55.2 ng/ml for positive tests, positive IGF-1R-Abs were more frequent in GD (25%), than in AT (3.7%, P = 0.003) and healthy subjects (0%, P = 0.006). Within GD, there was no difference between patients with or without GO. Serum levels of IGF-1R-Abs differed across the study population (P < 0.0001), reflecting their higher concentrations in GD (P < 0.0001 vs both AT and healthy subjects), but with no difference between patients with or without GO. In patients with GO, there was an inverse correlation between serum IGF-1R-Abs and CAS (R = - 0.376, 95% CI: from - 0.373 to - 0.631; P = 0.005), the significance of which remains to be investigated.

CONCLUSIONS

Serum autoantibodies against the IFG-1R are present in one-fourth of GD patients, regardless of the presence of GO. Further functional studies are needed to investigate the significance of their inverse correlation with GO activity.

Molecular biomarkers of Graves' ophthalmopathy

Graves' ophthalmopathy (GO), a complication of Graves' disease (GD), is typified by orbital inflammation, ocular tissue expansion and remodeling and, ultimately, fibrosis. Orbital fibroblasts are key effectors of GO pathogenesis exhibiting exaggerated inflammatory and fibroproliferative responses to cytokines released by infiltrating immune cells. Activated orbital fibroblasts also produce inflammatory mediators that contribute to disease progression, facilitate the orbital trafficking of monocytes and macrophages, promote differentiation of matrix-producing myofibroblasts and stimulate accumulation of a hyaluronan-rich stroma, which leads to orbital tissue edema and fibrosis. Proteomic and transcriptome profiling of the genomic response of ocular and non-ocular fibroblasts to INF-γ and TGF-β1 focused on identification of translationally-relevant therapeutic candidates. Induction of plasminogen activator inhibitor-1 (PAI-1, SERPINE1), a clade E member of the serine protease inhibitor (SERPIN) gene family and a prominent regulator of the pericellular proteolytic microenvironment, was one of the most highly up-regulated proteins in INF-γ- or TGF-β1-stimulated GO fibroblasts as well as in severe active GD compared to patients without thyroid disease. PAI-1 has multifunctional roles in inflammatory and fibrotic processes that impact tissue remodeling, immune cell trafficking and survival as well as signaling through several receptor systems. This review focuses on the pathophysiology of the GO fibroblast and possible targets for effective drug therapy.

World leaders describe the latest in IGF research

One of the most pervasive systems in biology is the insulinlike growth factor (IGF) system of ligands, binding proteins and receptors. Since their discovery in the 1950s, the interest in the IGFs has motivated biologists, biochemists, molecular geneticists, evolutionists, physiologist, pharmacologists and pharmaceutical and biotech companies. The IGF system plays important roles in normal physiology but in addition has been shown to be intimately involved in a wide array of disease processes including growth retardation, diabetes, cancer and neurological disorders, to name but a few. Thus, there has been interest in stimulating the IGF system on the one hand and inhibiting the system on the other hand. The current issue has been created on a range of topics that cover some of the recent developments in the field to give the reader a taste of this exciting and relevant biological system.