MANAGEMENT OF ENDOCRINE DISEASE: Rituximab therapy for Graves' orbitopathy - lessons from randomized control trials

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.

Novel insights into the pathogenesis of thyroid eye disease through ferroptosis-related gene signature and immune infiltration analysis

Thyroid eye disease (TED) has brought great physical and mental trauma to patients worldwide. Although a few potential signaling pathways have been reported, knowledge of TED remains limited. Our objective is to explore the fundamental mechanism of TED and identify potential therapeutic targets using diverse approaches. To perform a range of bioinformatic analyses, such as identifying differentially expressed genes (DEGs), conducting enrichment analysis, establishing nomograms, analyzing weighted gene correlation network analysis (WGCNA), and studying immune infiltration, the datasets GSE58331, GSE105149, and GSE9340 were integrated. Further validation was conducted using qPCR, western blot, and immunohistochemistry techniques. Eleven ferroptosis-related DEGs derived from the lacrimal gland were originally screened. Their high diagnostic value was proven, and diagnostic prediction nomogram models with high accuracy and robustness were established by using machine learning. A total of 15 hub gene-related DEGs were identified by WGCNA. Through CIBERSORTx, we uncovered five immune cells highly correlated with TED and found several special associations between these immune cells and the above DEGs. Furthermore, EGR2 from the thyroid sample was revealed to be closely negatively correlated with most DEGs from the lacrimal gland. High expression of APOD, COPB2, MYH11, and MYCN, as well as CD4/CD8 T cells and B cells, was verified in the periorbital adipose tissues of TED patients. To summarize, we discovered a new gene signature associated with ferroptosis that has a critical impact on the development of TED and provides valuable insights into immune infiltration. These findings might highlight the new direction and therapeutic strategies of TED.

Proof-of-concept and Randomized, Placebo-controlled Trials of an FcRn Inhibitor, Batoclimab, for Thyroid Eye Disease

CONTEXT

Inhibition of the neonatal fragment crystallizable receptor (FcRn) reduces pathogenic thyrotropin receptor antibodies (TSH-R-Ab) that drive pathology in thyroid eye disease (TED).

OBJECTIVE

We report the first clinical studies of an FcRn inhibitor, batoclimab, in TED.

DESIGN

Proof-of-concept (POC) and randomized, double-blind placebo-controlled trials.

SETTING

Multicenter.

PARTICIPANTS

Patients with moderate-to-severe, active TED.

INTERVENTION

In the POC trial, patients received weekly subcutaneous injections of batoclimab 680 mg for 2 weeks, followed by 340 mg for 4 weeks. In the double-blind trial, patients were randomized 2:2:1:2 to weekly batoclimab (680 mg, 340 mg, 255 mg) or placebo for 12 weeks.

MAIN OUTCOME

Change from baseline in serum anti-TSH-R-Ab and total IgG (POC); 12-week proptosis response (randomized trial).

RESULTS

The randomized trial was terminated because of an unanticipated increase in serum cholesterol; therefore, data from 65 of the planned 77 patients were analyzed. Both trials showed marked decreases in pathogenic anti-TSH-R-Ab and total IgG serum levels (P < .001) with batoclimab. In the randomized trial, there was no statistically significant difference with batoclimab vs placebo in proptosis response at 12 weeks, although significant differences were observed at several earlier timepoints. In addition, orbital muscle volume decreased (P < .03) at 12 weeks, whereas quality of life (appearance subscale) improved (P < .03) at 19 weeks in the 680-mg group. Batoclimab was generally well tolerated, with albumin reductions and increases in lipids that reversed upon discontinuation.

CONCLUSIONS

These results provide insight into the efficacy and safety of batoclimab and support its further investigation as a potential therapy for TED.

Rapamycin improves Graves' orbitopathy by suppressing CD4+ cytotoxic T lymphocytes

CD4+ cytotoxic T lymphocytes (CTLs) were recently implicated in immune-mediated inflammation and fibrosis progression of Graves' orbitopathy (GO). However, little is known about therapeutic targeting of CD4+ CTLs. Herein, we studied the effect of rapamycin, an approved mTOR complex 1 (mTORC1) inhibitor, in a GO mouse model, in vitro, and in patients with refractory GO. In the adenovirus-induced model, rapamycin significantly decreased the incidence of GO. This was accompanied by the reduction of both CD4+ CTLs and the reduction of orbital inflammation, adipogenesis, and fibrosis. CD4+ CTLs from patients with active GO showed upregulation of the mTOR pathway, while rapamycin decreased their proportions and cytotoxic function. Low-dose rapamycin treatment substantially improved diplopia and the clinical activity score in steroid-refractory patients with GO. Single-cell RNA-Seq revealed that eye motility improvement was closely related to suppression of inflammation and chemotaxis in CD4+ CTLs. In conclusion, rapamycin is a promising treatment for CD4+ CTL-mediated inflammation and fibrosis in GO.

Therapeutic effect of ibrutinib, a selective Bruton's tyrosine kinase inhibitor, in orbital fibroblasts from patients with Graves' orbitopathy

PURPOSE

Bruton's tyrosine kinase (BTK) is an essential protein in B-cell antigen receptor (BCR) signaling pathway and is known to be related to pathogenetic effect on B-cell related malignancies and various autoimmune diseases. In this study, we investigated the therapeutic effect of ibrutinib, an orally bioavailable BTK inhibitor in the pathogenesis of Graves' orbitopathy (GO) in in vitro model.

METHODS

Expression of BTK in orbital tissues from GO and normal control subjects were evaluated by real-time polymerase chain reaction (PCR). Primary cultured orbital fibroblasts from each subject were exposed to ibrutinib and stimulated with interleukin (IL)-1β or insulin like growth factor (IGF)-1. Production of inflammatory cytokines was evaluated by real time PCR and enzyme-linked immunosorbent assays (ELISA). The downstream transcription factors were also determined by western blot assays.

RESULTS

The expression of BTK in GO tissues were significantly higher than in healthy controls. After stimulation of GO orbital fibroblasts with IL-1β or IGF-1, BTK mRNA and phosphorylated (p)- BTK protein expression was also enhanced. Ibrutinib reduced the expression of BTK mRNA and proteins of p-BTK, and inhibited the IL-1β- and IGF-1-induced production of proinflammatory cytokines including IL-6, IL-8 and COX-2 in both GO and normal cells. Ibrutinib also significantly attenuated phosphorylation of Akt, p38, c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and nuclear factor kappa-light-chain-enhancer of activated B-cells (NF-κB) in IL-1β stimulated GO cells and Akt, JNK, and NF-κB in IL-1ß stimulated normal cells.

CONCLUSIONS

BTK expression is enhanced in GO tissue and orbital fibroblasts. Ibrutinib, a BTK inhibitor suppresses proinflammatory cytokine production as well as phosphorylation of Akt and NF-κB protein. Our results suggest the potential role of BTK in GO inflammatory pathogenesis and possibility of a novel therapeutic target of GO.

Management of Thyroid Eye Disease: A Consensus Statement by the American Thyroid Association and the European Thyroid Association

Thyroid eye disease (TED) remains challenging for clinicians to evaluate and manage. Novel therapies have recently emerged, and their specific roles are still being determined. Most patients with TED develop eye manifestations while being treated for hyperthyroidism and under the care of endocrinologists. Endocrinologists, therefore, have a key role in diagnosis, initial management, and selection of patients who require referral to specialist care. Given that the need for guidance to endocrinologists charged with meeting the needs of patients with TED transcends national borders, and to maximize an international exchange of knowledge and practices, the American Thyroid Association and European Thyroid Association joined forces to produce this consensus statement.

Management of thyroid eye disease: a Consensus Statement by the American Thyroid Association and the European Thyroid Association

Thyroid eye disease (TED) remains challenging for clinicians to evaluate and manage. Novel therapies have recently emerged, and their specific roles are still being determined. Most patients with TED develop eye manifestations while being treated for hyperthyroidism and under the care of endocrinologists. Endocrinologists, therefore, have a key role in diagnosis, initial management, and selection of patients who require referral to specialist care. Given that the need for guidance to endocrinologists charged with meeting the needs of patients with TED transcends national borders, and to maximize an international exchange of knowledge and practices, the American Thyroid Association and European Thyroid Association joined forces to produce this Consensus Statement.

A Survey on the Management of Thyroid Eye Disease Among American and European Thyroid Association Members

Background: The thyroid eye disease (TED) treatment landscape is rapidly evolving. How new treatment options have impacted practice is unknown. Methods: We conducted a cross-sectional electronic survey of American and European Thyroid Association members between June 2 and June 30, 2021. The survey included TED questions about resources for its management, index cases for different severities and presentations of TED, barriers for the management of TED, and participants' concerns about TED. We classified respondents into three geographic categories: North America, Europe, or other regions. Results: Two hundred fifty-two eligible participants started the survey (15% response rate), and 227 completed it. Participants were mostly men (50.2%, 114/227), white (79.7%, 181/227), endocrinologists with a thyroid focus (66.1%, 150/227), practicing in a tertiary academic center (46.7%, 106/227), caring for 10 or more TED patients over the last 12 months (40.5%, 92/227), and reported not having a multidisciplinary TED clinic in their institution (52.8%, 120/227). The majority reported that new TED cases per annum have not changed in the past 10 years (47.5%, 108/227), and that TED patients are found in practice during the management of hyperthyroidism (41.8%, 95/227). For mild active TED, participants from Europe reported a higher use of selenium (73%[96/132] vs. 32%[20/62] of respondents from North America and 24%[8/33] of respondents from other regions). For moderate-to-severe active TED, there was a modest preference for teprotumumab as first-line therapy (37%, 23/62) among North American participants and intravenous (IV) steroids (73%[96/132], and 42%[14/33]) for participants from Europe and other regions, respectively. These treatment preferences did not change in patients with moderate-to-severe active TED with poorly controlled diabetes. In contrast, participants from the three geographic categories preferred IV steroids for optic neuropathy and women planning pregnancy. The three top "very important" concerns about TED management according to participants were: the cost of TED treatment (31.3%, 71/227), lack of effective TED treatments (19.8%, 45/227), and difficulty in predicting whether TED will develop (18.9%, 43/227). Conclusions: There is a marked geographic practice variation in the management of TED. Clinicians' concerns about TED management demand ongoing research on more effective treatment, TED predictive tools, and policy changes to improve the affordability of new TED therapies.

Rituximab in the treatment of Graves' orbitopathy: latest updates and perspectives

Graves' orbitopathy (GO) is a potentially sight-threatening and disfiguring, extrathyroidal manifestation of Graves' disease. It often impairs patients' quality of life, causing severe social and psychological sequelae. Intravenous glucocorticosteroids is currently the mainstay of therapy, but the efficacy is often underwhelming and recurrence rate is high. For many years, clinicians have been searching for new methods of treatment. Rituximab (RTX) is a chimeric monoclonal antibody targeted against CD20 which is a surface antigen present on B cells. It is frequently used to treat non-Hodgkin's lymphoma, chronic lymphocytic leukemia, rheumatoid arthritis, or various types of vasculitis. Numerous clinical trials employing RTX in the treatment of GO have shown promising results. RTX is currently considered to be a valid second-line treatment option in patients unresponsive to previous interventions or in disease reactivation. This review summarizes the available literature on this topic, including two largest, randomized, controlled studies. Potential benefits, as well as the limitations of RTX therapy, are discussed.

Current concepts regarding Graves' orbitopathy

Graves' orbitopathy (GO) is an orbital autoimmune disorder and the main extrathyroidal manifestation of Graves' disease, the most common cause of hyperthyroidism. GO affects about 30% of Graves' patients, although fewer than 10% have severe forms requiring immunosuppressive treatments. Management of GO requires a multidisciplinary approach. Medical therapies for active moderate-to-severe forms of GO (traditionally, high-dose glucocorticoids) often provide unsatisfactory results, and subsequently surgeries are often needed to cure residual manifestations. The aim of this review is to provide an updated overview of current concepts regarding the epidemiology, pathogenesis, assessment, and treatment of GO, and to present emerging targeted therapies and therapeutic perspectives. Original articles, clinical trials, systematic reviews, and meta-analyses from 1980 to 2021 were searched using the following terms: Graves' disease, Graves' orbitopathy, thyroid eye disease, glucocorticoids, orbital radiotherapy, rituximab, cyclosporine, azathioprine, teprotumumab, TSH-receptor antibody, smoking, hyperthyroidism, hypothyroidism, thyroidectomy, radioactive iodine, and antithyroid drugs. Recent studies suggest a secular trend toward a milder phenotype of GO. Standardized assessment at a thyroid eye clinic allows for a better general management plan. Treatment of active moderate-to-severe forms of GO still relies in most cases on high-dose systemic-mainly intravenous-glucocorticoids as monotherapy or in combination with other therapies-such as mycophenolate, cyclosporine, azathioprine, or orbital radiotherapy-but novel biological agents-including teprotumumab, rituximab, and tocilizumab-have achieved encouraging results.

Future Projections in Thyroid Eye Disease

BACKGROUND AND AIMS

This review aims to summarize current and emerging therapies for treatment of thyroid eye disease (TED), in the light of novel understanding of pathogenetic mechanisms, leading to new treatment options and clinical trials.

METHODS

We reviewed and analyzed peer-reviewed literature reporting recent translational studies and clinical trials in the treatment of TED. Searches were made at www.pubmed.gov with keywords "thyroid eye disease," "Graves' ophthalmopathy," "thyroid orbitopathy," and "Graves' orbitopathy."

RESULTS

Surgery is reserved for rehabilitation in chronic TED or for emergent compressive optic neuropathy. Oral and intravenous glucocorticoid therapy has been used for decades with variable efficacy in acute TED, but results may be temporary and side effects significant. Nonsteroidal oral immunosuppressive agents offer modest benefit in TED. Several immunomodulatory monoclonal antibodies, including rituximab and tocilizumab, have shown efficacy for inactivating TED. Recently, teprotumumab, an insulin-like growth factor 1 receptor (IGF-1R) inhibitor, has demonstrated significant improvement in proptosis, clinical activity score, diplopia, and quality of life in patients with active TED, with good tolerability. Newly proposed TED therapies, currently in preclinical and clinical trial phases, include thyroid-stimulating hormone (TSH) receptor inhibitory drugs, RVT-1401, local anti-vascular endothelial growth factor therapy, IGF-1R drugs delivered subcutaneously and orally, and desensitization to the TSH receptor with modified TSH receptor peptides.

CONCLUSION

New, albeit incomplete, understanding of the molecular mechanisms of TED has led to new promising therapies and offered improved outcomes in TED patients. Their full role and their relationship to classical immune suppression should be clarified over the next few years.

Rituximab for thyroid-associated ophthalmopathy

BACKGROUND

Thyroid-associated ophthalmopathy (TAO) is the most frequent extrathyroidal manifestation of Graves' disease, affecting up to 50% of patients. It has a great impact on quality of life. Rituximab (RTX) is a human/murine chimeric monoclonal antibody that targets the CD20 receptor on B-lymphocytes. Preliminary work has shown that blocking this CD20 receptor with RTX may affect the clinical course of TAO by reducing inflammation and the degree of proptosis.  OBJECTIVES: This review update, originally published in 2013, assesses the efficacy and safety of using RTX for the treatment of TAO.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2022, Issue 2), which contains the Cochrane Eyes and Vision Trials Register, Ovid MEDLINE, Ovid Embase, Latin American and Caribbean Health Science Information database (LILACS), the ISRCTN registry, clinicaltrials.gov and the WHO International Clinical Trials Registry Platform (WHO ICTRP). There were no language restrictions in the electronic search for trials. We last searched the electronic databases on 22 February 2022.  SELECTION CRITERIA: We included randomised controlled trials (RCTs) of RTX administered by intravenous infusion using any dosage regimen for the treatment of active TAO in adults, compared to placebo or glucocorticoids treatment.  DATA COLLECTION AND ANALYSIS: We used standard methodological procedures expected by Cochrane. Two review authors independently scanned titles and abstracts, and screened full-text reports of potentially relevant studies. The outcomes of interest in this review were: clinical activity score (CAS), NOSPECS severity scale, proptosis (mm), palpebral aperture (mm), extraocular motility (degrees or diplopia rating scale), quality of life and adverse effects.

MAIN RESULTS

We identified two studies that met the inclusion criteria in this updated review. Across both studies, the mean age of participants was 55 years and 77% were women. RTX compared to intravenous methylprednisolone (IVMP) One study, conducted in Italy, compared RTX (n = 15 after one participant withdrew) with IVMP (n = 16) for active TAO (CAS ≥ 3 out of 7 or 4 out of 10). We judged this study to be at low risk of bias in most domains, but it was stopped early because of disease reactivation in the comparator group (5/16 participants). This study provided low-certainty evidence that RTX may result in CAS improvement at 24 weeks compared to IVMP (15/15 versus 12/16 improved by ≥ 2 points; risk ratio (RR) 1.32, 95% confidence interval (CI) 0.98 to 1.78). Only very low-certainty evidence was available for the other outcomes: NOSPECS improvement by 2 or more classes (3/15 versus 3/16; RR 1.07, 95% CI 0.25 to 4.49); proptosis improvement by 2 mm or more (0/15 versus 1/16; RR 0.35, 95% CI 0.02 to 8.08); palpebral aperture improvement by 3 mm or more (2/15 versus 0/16; RR 5.31, 95% CI 0.28 to 102.38); motility improvement by 1 class or more (3/15 versus 3/16; RR 1.07, 95% CI 0.25 to 4.49); and improvement on the Graves' ophthalmopathy QoL scale by at least 6 points for "functioning" (5/14 versus 8/13; RR 0.58, 95% CI 0.25 to 1.32), and "appearance" (9/14 versus 6/13; RR 1.39, 95% CI 0.69 to 2.82). Adverse events were more common in the RTX group (RR 1.39, 95% CI 0.90 to 2.13; low-certainty evidence). Minor adverse effects (mild infusion reactions) were observed in most people receiving RTX at first infusion. Two participants experienced a major infusion reaction, likely cytokine release syndrome. RTX compared to placebo One study, conducted in the USA, enrolled 25 participants with active TAO (CAS ≥ 4 out of 7), comparing RTX (13 participants) to placebo. We judged this study to be at low risk of bias in most domains, but it was stopped early due to recruitment issues. It provided very low-certainty evidence on the following outcomes at 24 weeks: CAS improvement by 2 or more points (4/13 RTX versus 3/12 placebo; RR 1.23, 95% CI 0.34 to 4.40); NOSPECS improvement by 2 or more classes (2/13 versus 2/12; RR 0.92, 95% CI 0.15 to 5.56); proptosis improvement by 2 mm or more (2/13 versus 4/12; RR 0.46, 95% CI 0.10 to 2.08); palpebral aperture median change (0 mm in RTX group, in both eyes separately, versus -0.5 mm and 0.5 mm in placebo group right and left eye, respectively); motility median diplopia score (3 versus 2.5); SF-12 physical component median score (45.9 versus 40.3) and mental component median score (52.8 versus 46.1). More participants in the RTX group experienced adverse effects (8/13 versus 3/12; RR 2.46, 95% CI 0.84 to 7.18).  AUTHORS' CONCLUSIONS: There is currently insufficient evidence to support the use of RTX in people with TAO. Future studies investigating RTX in people with active TAO may need to be multi-centre in order to recruit enough participants to make an adequate judgement on the efficacy and safety of this novel therapy.

Advances in the Treatment of Thyroid Eye Disease Associated Extraocular Muscle Myopathy and Optic Neuropathy

PURPOSE OF REVIEW

To review emerging treatments for thyroid eye disease (TED) associated extraocular muscle myopathy and dysthyroid optic neuropathy (DON).

RECENT FINDINGS

Emerging targeted biologic therapies may alter the disease course in TED. Teprotumumab, a type I insulin-like growth factor receptor inhibitor, is the most recent addition to the treatments available for TED-associated extraocular muscle myopathy causing diplopia. Small studies also suggest a potential therapeutic benefit for DON. Various recent studies have also expanded our knowledge on conventional TED therapies. The therapeutic landscape of TED and its sequelae has evolved in recent years. New targeted therapies have the potential to reduce the extraocular muscle and orbital volume expansion which can lead to diplopia and vision loss from optic nerve compression. Longer term efficacy and durability data is needed to determine the role biologics, such as teprotumumab, should play in the treatment of TED patients compared to the current standard of care.

TSH receptor specific monoclonal autoantibody K1-70TM targeting of the TSH receptor in subjects with Graves' disease and Graves' orbitopathy-Results from a phase I clinical trial

OBJECTIVES

In Graves' disease (GD), autoantibodies to the thyroid stimulating hormone receptor (TSHR) cause hyperthyroidism. The condition is often associated with eye signs including proptosis, oedema, and diplopia (collectively termed Graves' orbitopathy [GO]). The safety profile of K1-70^TM (a human monoclonal TSHR specific autoantibody, which blocks ligand binding and stimulation of the receptor) in patients with GD was evaluated in a phase I clinical trial.

PATIENTS AND STUDY DESIGN

Eighteen GD patients stable on antithyroid drug medication received a single intramuscular (IM) or intravenous (IV) dose of K1-70^TM during an open label phase I ascending dose, safety, tolerability, pharmacokinetic and pharmacodynamic (PD) study. Immunogenic effects of K1-70^TM were also determined.

RESULTS

K1-70^TM was well-tolerated in all subjects at all doses and no significant immunogenic response was observed. There were no deaths or serious adverse events. Increased systemic exposure to K1-70^TM was observed following a change to IV dosing, indicating this was the correct dosage route. Expected PD effects occurred after a single IM dose of 25 mg or single IV dose of 50 mg or 150 mg with fT3, fT4, and TSH levels progressing into hypothyroid ranges. There were also clinically significant improvements in symptoms of both GD (reduced tremor, improved sleep, improved mental focus, reduced toilet urgency) and GO (reduced exophthalmos measurements, reduced photosensitivity).

CONCLUSIONS

K1-70^TM was safe, well tolerated and produced the expected PD effects with no immunogenic responses. It shows considerable promise as a new drug to block the actions of thyroid stimulators on the TSHR.

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.

2021 update on thyroid-associated ophthalmopathy

PURPOSE

Our understanding of thyroid-associated ophthalmopathy (TAO, A.K.A Graves' orbitopathy, thyroid eye disease) has advanced substantially, since one of us (TJS) wrote the 2010 update on TAO, appearing in this journal.

METHODS

PubMed was searched for relevant articles.

RESULTS

Recent insights have resulted from important studies conducted by many different laboratory groups around the World. A clearer understanding of autoimmune diseases in general and TAO specifically emerged from the use of improved research methodologies. Several key concepts have matured over the past decade. Among them, those arising from the refinement of mouse models of TAO, early stage investigation into restoring immune tolerance in Graves' disease, and a hard-won acknowledgement that the insulin-like growth factor-I receptor (IGF-IR) might play a critical role in the development of TAO, stand out as important. The therapeutic inhibition of IGF-IR has blossomed into an effective and safe medical treatment. Teprotumumab, a β-arrestin biased agonist monoclonal antibody inhibitor of IGF-IR has been studied in two multicenter, double-masked, placebo-controlled clinical trials demonstrated both effectiveness and a promising safety profile in moderate-to-severe, active TAO. Those studies led to the approval by the US FDA of teprotumumab, currently marketed as Tepezza for TAO. We have also learned far more about the putative role that CD34⁺ fibrocytes and their derivatives, CD34⁺ orbital fibroblasts, play in TAO.

CONCLUSION

The past decade has been filled with substantial scientific advances that should provide the necessary springboard for continually accelerating discovery over the next 10 years and beyond.

Observation study of using a small dose of rituximab treatment for thyroid-associated ophthalmopathy in seven Chinese patients: One pilot study

OBJECTIVE

To report the efficacy, long-term safety, and tolerability of using a small dose (125 mg/m2 weekly for 4 weeks) of rituximab to treat Chinese patients with thyroid-associated ophthalmopathy (TAO).

METHODS

Seven patients with active moderate-to-severe TAO were prospectively recruited in this study. A small dose of rituximab (125mg/m2 body surface area) was given weekly with a duration of four weeks. Thyroid function, thyrotropin receptor antibody (TRAb), B cell and T cell subsets, ophthalmological examination, magnetic resonance imaging derived parameters, and adverse reactions were recorded at each visit.

RESULTS

Seven patients were followed for an average of 224 weeks. B-cell depletion was observed in all patients following rituximab infusion. The clinical activity score (CAS) decreased from 4.86 ± 0.69 to 3.00 ± 0.82 at 5 weeks after treatment (P = 0.033) and remained significantly lower than baseline values at the end of follow-up (P = 0.001). Compared to baseline values, significant decreases in exophthalmos of the right eye, the thickness of extraocular muscles with maximum signal intensity, and the highest signal intensity ratio (SIR) of extraocular muscle to ipsilateral temporal muscle values were observed at the last follow-up (all P < 0.05). Disease progressions or recurrences were not observed during follow-up. Only mild fatigue was observed after the first infusion as a side effect (n = 1).

CONCLUSION

Small dose of rituximab may be a promising option with adequate safety, tolerability, and long-term efficacy for patients with active moderate-to-severe TAO.

Thyroid eye disease: From pathogenesis to targeted therapies

Thyroid eye disease (TED) is the most common extrathyroidal manifestation of autoimmune Graves’ hyperthyroidism. TED is a debilitating and potentially blinding disease with unclear pathogenesis. Autoreactive inflammatory reactions targeting orbital fibroblasts (OFs) lead to the expansion of orbital adipose tissues and extraocular muscle swelling within the fixed bony orbit. There are many recent advances in the understating of molecular pathogenesis of TED. The production of autoantibodies to cross-linked thyroid-stimulating hormone receptor and insulin-like growth factor-1 receptor (IGF-1R) activates OFs to produce significant cytokines and chemokines and hyaluronan production and to induce adipocyte differentiation. In moderately severe active TED patients, multicenter clinical trials showed that inhibition of IGF-1R with teprotumumab was unprecedentedly effective with minimal side effects. The emergence of novel biologics resulted in a paradigm shift in the treatment of TED. We here review the literature on advances of pathogenesis of TED and promising therapeutic targets and drugs.

Management of eyelid retraction related to thyroid eye disease

Eyelid retraction related to thyroid eye disease (TED) is a challenging condition. It is one of the main clinical signs and a major diagnostic criterion in TED. This condition may threaten vision due to exposure keratopathy, in addition to its esthetic alterations, which may lead to psychosocial implications and affect the patient's quality of life. Although it is more commonly observed in the upper eyelid, it may be present on both the upper and lower lids. Numerous surgical and nonsurgical treatment modalities have been described and will be reviewed in this article. Management should be based on an individual patient assessment, taking into consideration the disease stage, severity, and clinician experience.

[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.

Intravenous rituximab therapy for active Graves' ophthalmopathy: a meta-analysis

AIM

The successful treatment of Graves' ophthalmopathy (GO) remains a challenge, while the efficacy of rituximab (RTX) is at present controversial. The aim of this meta-analysis was to investigate the potential impact of intravenous RTX therapy in patients with GO.

METHODS

We performed a search in the PubMed, Embase, and Web of Science databases for relevant studies published before July 2020. The primary outcome was the change of clinical activity score (CAS), and secondary outcomes were the change of proptosis and TSH receptor antibodies (TRAb). A meta-analysis was conducted to calculate the standard mean difference (SMD) for these outcomes by using fixed- or random-effect models.

RESULTS

Analysis of outcomes in 152 patients collected from 12 published articles was conducted. Compared to baseline value, CAS was significantly decreased at 1, 6, 12, and >12 months after RTX treatment. For proptosis, the results revealed no significant decrease at 1-3, 6, and ≥12 months. Moreover, the pooled analysis employed in this meta-analysis showed no significant difference of TRAb at 1 month, but significant declines were observed at 6 and ≥12 months.

CONCLUSION

Our results strongly suggest that intravenous RTX treatment has an acute and long-lasting beneficial effect on decreasing both CAS and TRAb. The study also indicates that the effect of RTX on proptosis is limited. There is evidently a need to investigate the mechanism behind RTX ineffectiveness on proptosis and explore other therapeutic regimens for the reduction of proptosis.

Efficacy Profile and Safety of Very Low-Dose Rituximab in Patients with Graves' Orbitopathy

Background: Rituximab (RTX), a chimeric human-murine anti-CD20 monoclonal antibody, has been used for treatment of active moderate-severe Graves' orbitopathy (GO) since 2004 as second-line therapy in patients unresponsive to intravenous steroids. We conducted an open-label prospective study (EUDRACT 2012-001980-53) in which patients were treated with a single infusion of only 100 mg RTX to analyze the efficacy and safety of this low dose. Methods: Seventeen patients, of whom nine had disease that was unresponsive to intravenous methylprednisolone and eight with newly diagnosed GO, were enrolled. Disease activity was assessed with the clinical activity score (CAS) and severity with a composite ophthalmic score. Long-term surgical treatment and quality of life were also assessed, as well as treatment-related adverse events. Results: Mean baseline CAS was 4.56 ± 0.96 and decreased to 1.25 ± 1.14 at 24 weeks (p = 0.001). Disease inactivation occurred within 24 weeks in >90% of patients and was unrelated to disease duration. Severity improved in about 60% of patients, with no relapses. All patients showed peripheral depletion of CD20⁺ and CD19⁺ cells at the end of RTX infusion (60 minutes). Two patients required surgical orbital decompression because of optic neuropathy (ON). Among adverse events observed, there was one patient who developed a cytokine release syndrome. Conclusions: A dose of 100 mg RTX is effective in patients with active moderate-severe GO. Low doses are better tolerated, expose patients to immune suppression for a shorter period of time, and are extremely cost effective, compared with higher doses. This dose, consistently with all other immunosuppressants, does not prevent the progression of GO to dysthyroid ON.

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.

Selenium in the Treatment of Graves' Hyperthyroidism and Eye Disease

Based on the role of oxidative stress in the pathogenesis of Graves' hyperthyroidism (GH) and Graves' Orbitopathy (GO), a therapy with the antioxidant agent selenium has been proposed and a number of studies have been performed, both in vitro and in vivo. In GH, reactive oxygen species (ROS) contribute to the thyroid and peripheral tissues damage. In GO, tissue hypoxia, as well as ROS, are involved in the typical changes that occur in fibroadipose orbital tissue and the perimysium of extraocular muscles. Antioxidants have been proposed to improve the effects of antithyroid drugs in GH patients, as well as the remodeling of orbital tissues in patients with GO. Here, we reviewed the literature on the possible beneficial effects and clinical use of selenium in the management of patients with GH and GO. A randomized clinical trial on the use of selenium in patients with mild GO provided evidence for a beneficial effect; no data are available on more severe forms of GO. Although the real effectiveness of selenium in patients with GH remains questionable, its use in the management of mild GO is generally believed to be beneficial, and selenium administration has been included in the clinical practice for the patients with mild eye disease.

Therapy With Different Dose Regimens of Rituximab in Patients With Active Moderate-To-Severe Graves' Orbitopathy

BACKGROUND

Immunosuppressive therapy of Graves' orbitopathy (GO) is indicated during the active phase of disease. Intravenous steroids (IVGC) are effective in about 70% of patients, although unresponsiveness or relapse are observed. In previous studies, rituximab (RTX) has been shown to be effective in inactivating moderate-to-severe GO when used early in the disease, but its optimal dosage has never been studied in randomized clinical trials. Aim of this study was to compare the efficacy and safety of different doses of RTX, based on a post-hoc analysis of two open label studies and one prospective trial randomized to IVGC.

METHODS

of 40 patients (35 women, 5 men), with active moderate-to-severe GO treated with RTX, 14 received a single dose of 100 mg (Group 1), 15 a single dose of 500 mg (Group 2) and 11 two 1000 mg doses, administered one week apart (Group 3). Thyroid function, TSH-receptor antibodies (TRAb) and peripheral CD19+ cells were measured. Primary endpoint was disease inactivation, measured as a decrease of the Clinical Activity Score (CAS) of at least two points. Secondary endpoints were improvement of proptosis, diplopia, quality of life and safety.

RESULTS

Baseline CAS decreased significantly in all groups (P<0.0001), independently of GO duration or whether patients had newly occurring or relapsing GO after IVGC. Proptosis did not significantly change. There was an inverse correlation between the Gorman score for diplopia and RTX dose (P<0.01). The appearance score of the GO-QoL improved in Group 1 (P=0.015), and the visual function score, in Group 2 (P=0.04). A reduction of serum TRAb was observed in Group 1 (P=0.002) and Group 2 (P<0.0002), but not in Group 3. CD19+ cell decreased in all groups (P<0.01), independently of the dose.

CONCLUSIONS

We studied the optimal dosage of RTX in the treatment of active moderate-to-severe GO. In this analysis, we considered the efficacy of RTX in inactivating GO, in changing its natural course, its effect on disease severity and on the patients' quality of life. Based on our clinical findings, and balancing the cost of therapy, a single 500 mg dose regimen is suggested in the majority of patients.

Oxidative Stress in Graves Disease and Graves Orbitopathy

Oxidative stress is involved in the pathogenesis of Graves hyperthyroidism (GH) and Graves orbitopathy (GO) and an antioxidant approach has been proposed for both. In GH, a disbalance of the cell redox state is associated with thyroid hyperfunction and antithyroid medications may reduce oxidative stress. Tissue hypoxia participates in the pathogenesis of GO, and oxygen free radicals are involved in the typical changes of orbital tissues as reported by in vitro and clinical studies. Antioxidant agents, especially selenium, have been proposed as a therapeutic option for GH and GO. A clinical study regarding the use of selenium in mild GO has provided evidence for a beneficial effect in the short term, even though its beneficial effects in the long term are still to be investigated. In addition to selenium, a protective role of other antioxidant agents, i.e., quercetin, enalapril, vitamin C, N-acetyl-L-cysteine and melatonin has been suggested by in vitro studies, although clinical studies are lacking. Here, we review the role of oxidative stress and antioxidant agents in GH and GO.

Management of Graves Thyroidal and Extrathyroidal Disease: An Update

CONTEXT

Invited update on the management of systemic autoimmune Graves disease (GD) and associated Graves orbitopathy (GO).

EVIDENCE ACQUISITION

Guidelines, pertinent original articles, systemic reviews, and meta-analyses.

EVIDENCE SYNTHESIS

Thyrotropin receptor antibodies (TSH-R-Abs), foremost the stimulatory TSH-R-Abs, are a specific biomarker for GD. Their measurement assists in the differential diagnosis of hyperthyroidism and offers accurate and rapid diagnosis of GD. Thyroid ultrasound is a sensitive imaging tool for GD. Worldwide, thionamides are the favored treatment (12-18 months) of newly diagnosed GD, with methimazole (MMI) as the preferred drug. Patients with persistently high TSH-R-Abs and/or persistent hyperthyroidism at 18 months, or with a relapse after completing a course of MMI, can opt for a definitive therapy with radioactive iodine (RAI) or total thyroidectomy (TX). Continued long-term, low-dose MMI administration is a valuable and safe alternative. Patient choice, both at initial presentation of GD and at recurrence, should be emphasized. Propylthiouracil is preferred to MMI during the first trimester of pregnancy. TX is best performed by a high-volume thyroid surgeon. RAI should be avoided in GD patients with active GO, especially in smokers. Recently, a promising therapy with an anti-insulin-like growth factor-1 monoclonal antibody for patients with active/severe GO was approved by the Food and Drug Administration. COVID-19 infection is a risk factor for poorly controlled hyperthyroidism, which contributes to the infection-related mortality risk. If GO is not severe, systemic steroid treatment should be postponed during COVID-19 while local treatment and preventive measures are offered.

CONCLUSIONS

A clear trend towards serological diagnosis and medical treatment of GD has emerged.

Treatment of Graves' ophthalmopathy

Graves' ophthalmopathy is an inflammatory disease with primary involvement of the extraocular muscles and the orbit. It encompasses the most common extra-thyroid manifestation in patients with Graves-Basedow disease. The underlying cause is molecular mimicry with the TSH receptor in ocular fibroblasts, leading to an immuno-mediated pathogenesis. Glucocorticoids at high doses are the cornerstone in moderate-severe cases. However, some patients are corticorresistant or intolerant. In recent years, therapeutic novelties have been described in terms of the dosage of the immunosuppressive treatments used, as well as the emergence of biological therapy in this field. The objective of this review is to update the treatment of Graves' ophthalmopathy, as well as to present alternative options in patients resistant or intolerant to glucocorticoids.

Tocilizumab versus Rituximab in Patients with Moderate to Severe Steroid-resistant Graves' Orbitopathy

Introduction: To describe the efficacy of tocilizumab in patients with Graves' orbitopathy resistant or dependent to steroids and compare to rituximab treated patients.Patients and Methods: Graves's orbitopathy response was considered as decrease of at least 2 points of the CAS.Results: Twenty-one patients were included, 7 patients were treated with tocilizumab and 14 with rituximab. The primary was achieved in all 7 patients (100%) on tocilizumab and 9 out of 14 patients on (64%) rituximab (p = .17). Mean change in CAS was consistent with a decrease of 3.3 ± 0.5 points in patients on tocilizumab versus 2.5 ± 1.9 in patients on rituximab (p = .07). One patient on tocilizumab (14%) and 4 patients (29%) on rituximab experienced significant relapse during the follow-up. The difference in relapse-free survival was not significant in patients on tocilizumab (10.8 ± 4 months) compared with rituximab (17.88 ± 3.66).Conclusion: We showed a significant improvement in the CAS, visual acuity, diplopia, and proptosis with both tocilizumab and rituximab.

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.

Graves' disease

Graves' disease (GD) is an autoimmune disease that primarily affects the thyroid gland. It is the most common cause of hyperthyroidism and occurs at all ages but especially in women of reproductive age. Graves' hyperthyroidism is caused by autoantibodies to the thyroid-stimulating hormone receptor (TSHR) that act as agonists and induce excessive thyroid hormone secretion, releasing the thyroid gland from pituitary control. TSHR autoantibodies also underlie Graves' orbitopathy (GO) and pretibial myxoedema. Additionally, the pathophysiology of GO (and likely pretibial myxoedema) involves the synergism of insulin-like growth factor 1 receptor (IGF1R) with TSHR autoantibodies, causing retro-orbital tissue expansion and inflammation. Although the aetiology of GD remains unknown, evidence indicates a strong genetic component combined with random potential environmental insults in an immunologically susceptible individual. The treatment of GD has not changed substantially for many years and remains a choice between antithyroid drugs, radioiodine or surgery. However, antithyroid drug use can cause drug-induced embryopathy in pregnancy, radioiodine therapy can exacerbate GO and surgery can result in hypoparathyroidism or laryngeal nerve damage. Therefore, future studies should focus on improved drug management, and a number of important advances are on the horizon.

Efficacy of rituximab in patients with Graves' orbitopathy: a retrospective multicenter nationwide study

PURPOSE

The clinical utility of rituximab (RTX) in Graves' orbitopathy (GO) treatment remains controversial since the discrepant results from 2 prospective randomized studies (Stan M et al. J Clin Endocrinol Metab 2015; Salvi M et al. J Clin Endocrinol Metab 2015). The aim of this study was to assess in real life the characteristics and the clinical outcomes of patients with GO treated with RTX in cases of corticosteroid resistance or corticosteroid dependence.

METHODS

Multicenter French retrospective study including patients with moderate-to-severe GO requiring second-line treatment with RTX. Patients were classified according to three main baseline characteristics: clinical inflammation (CAS ≥ 3), oculomotor limitation, and visual dysfunction. Patients were considered as responders if, at 24 weeks (week 24), at least 1 of these 3 parameters improved with no worsening elsewhere.

RESULTS

Forty patients were included (65% smokers, 38% dysthyroidism). Thirty-two patients were treated with RTX alone (one patient excluded owing to side effects): 64.5% had favorable responses at week 24 and significant reduction in baseline CAS (3.29 ± 1.6) at 12 weeks (1.93 ± 1.1; P < 0.001) and at week 24 (1.59 ± 1.1; P < 0.001); reduction in anti-TSH receptor antibodies at week 24 (P < 0.01); and significant improvement of visual acuity (P = 0.04) and ocular hypertonia (P = 0.04) at week 12, but no improvement in oculomotor dysfunction. Eight patients needed emergency treatment with concomitant RTX and orbital decompression, with favorable outcome for 5 patients. Predictive factors for a poor response to RTX were low baseline CAS, smoker, and baseline ocular hypertonia. All patients reported good tolerance except one serious side effect (a cytokine release syndrome).

CONCLUSIONS

The efficiency results of RTX in reducing CAS in this cohort are just between those of Stan and Salvi. This could be explained by our delay before treatment initiation, quicker than Stan but longer than Salvi. RTX appears to be effective as a second-line treatment for the inflammatory component of GO, especially if the disease is highly active and recent.

Orbital diseases mimicking graves' orbitopathy: a long-standing challenge in differential diagnosis

Graves' orbitopathy (GO) is the most common cause of orbital tissue inflammation, accounting for ~ 60% of all orbital inflammatory conditions in the population aged 21-60 years, and for ~ 40% in the population aged > 60 year. GO is observed in 25-30% of patients with Graves' hyperthyroidism and more rarely in association with hypothyroid autoimmune thyroiditis. In addition, a small proportion of GO patients (1-2%) do not have a clinically overt thyroid dysfunction. Clinically, GO is characterized by proptosis, inflammation involving the eyelids and the conjunctiva, extraocular muscle hypertrophy, with consequent reduction of ocular motility and diplopia, and in the most severe cases, compression of the optic nerves at the orbital apex, with reduction of visual acuity. At CT scan or MRI, a muscle increase involving the superior, medial and inferior rectus is quite typical. In the most severe forms, compression of the optic nerves at the orbital apex can be observed. Euthyroid GO is usually an early sign of a full-blown Graves' disease; however, in some cases, the orbital disease can remain isolated. Moreover, euthyroid GO can rarely be unilateral, which makes the picture even more confusing. Under those circumstances, the diagnostic process becomes obviously quite difficult, having other conditions mimicking GO been excluded. A number of inflammatory conditions affecting orbital tissue can mimic GO, thereby requiring an accurate evaluation for a proper differential diagnosis. The majority of these conditions are immune mediated. Most of them are benign, but they can be rather aggressive and some can cause visual loss. The most common inflammatory condition affecting orbital tissues and mimicking GO is idiopathic orbital inflammation. Other, more rare, orbital diseases that should be considered in the differential diagnosis are infections, orbital manifestations of systemic diseases, primitive and secondary orbital neoplasms, and orbital vascular alterations. In most instances, when an orbitopathy occurs in the absence of hyperthyroidism, the diagnosis of the disease underlying the ocular symptoms and signs is based on exclusion of the other conditions. Here we review the conditions that can mimic GO and how to distinguish them from this obnoxious eye disease.

Immunohistochemical analysis of human orbital tissue in Graves' orbitopathy

PURPOSE

Immunohistochemistry of orbital tissues offers a correlation between the microscopic changes and macroscopic clinical manifestation of Graves' orbitopathy (GO). Summarizing the participation of different molecules will help us to understand the pathogenesis of GO.

METHODS

The pertinent and current literature on immunohistochemistry of human orbital tissue in GO was reviewed using the NCBI PubMed database.

RESULTS

33 articles comprising over 700 orbital tissue samples were included in this review. The earliest findings included the demonstration of HLA-DR and T cell (to a lesser extent B cell) markers in GO orbital tissues. Subsequent investigators further contributed by characterizing cellular infiltration, confirming the presence of HLA-DR and TSHR, as well as revealing the participation of cytokines, growth factors, adhesion molecules and miscellaneous substances. HLA-DR and TSHR are over-expressed in orbital tissues of GO patients. The inflammatory infiltration mainly comprises CD4 + T cells and macrophages. Cytokine profile suggests the importance of Th1 (especially in early active phase) and Th17 immunity in the pathogenesis of GO. Upregulation of proinflammatory/profibrotic cytokines, adhesion molecules and growth factors finally culminate in activation of orbital fibroblasts and perpetuation of orbital inflammation. The molecular status of selected parameters correlates with the clinical presentation of GO.

CONCLUSION

Further investigation is warranted to define precisely the role of different molecules and ongoing search for new players yet to be discovered is also important. Unfolding the molecular mechanisms behind GO will hopefully provide insights into the development of novel therapeutic strategies and optimize our clinical management of the disease.

New insights into the pathogenesis and nonsurgical management of Graves orbitopathy

Graves orbitopathy, also known as thyroid eye disease or thyroid-associated orbitopathy, is visually disabling, cosmetically disfiguring and has a substantial negative impact on a patient's quality of life. There is increasing awareness of the need for early diagnosis and rapid specialist input from endocrinologists and ophthalmologists. Glucocorticoids are the mainstay of treatment; however, recurrence occurs frequently once these are withdrawn. Furthermore, in >60% of cases, normal orbital anatomy is not restored, and skilled rehabilitative surgery is required. Clinical trials have shown that considerable benefit can be derived from the addition of antiproliferative agents (such as mycophenolate or azathioprine) in preventing deterioration after steroid cessation. In addition, targeted biologic therapies have shown promise, including teprotumumab, which reduces proptosis, rituximab (anti-CD20), which reduces inflammation, and tocilizumab, which potentially benefits both of these parameters. Other strategies such as orbital radiotherapy have had their widespread role in combination therapy called into question. The pathophysiology of Graves orbitopathy has also been revised with identification of new potential therapeutic targets. In this Review we provide an up-to-date overview of the field, outline the optimal management of Graves orbitopathy and summarize the research developments in this area to highlight future research questions and direct future clinical trials.

Thyroid eye disease: current and potential medical management

INTRODUCTION

Thyroid eye disease (TED) is the most frequent extra-thyroid manifestation of Graves' disease and it is more frequent in middle age and in female gender. Nowadays, the causal mechanisms of this disease are not completely understood, but the current available studies suggest that the main causative factor is the thyroid stimulating hormone receptor.

MATERIALS AND METHODS

To collect reports on TED medical management, a thorough literature search was performed in PubMed database. An additional search was made in Google Scholar to complete the collected items.

RESULTS

Among the indentified risk factors, tobacco habit is the most relevant. The main criteria to choose a suitable treatment are the activity and severity of the disease. Support measures can be used to improve the patient's symptoms in any phase of the disease. There is a large number of drugs proposed to manage TED, although with different reported rates of success.

CONCLUSIONS

Currently, the drugs of choice are corticosteroids in moderate-to-severe and in sight-threatening forms. The main problem of corticosteroids is their spectrum of side effects. Therefore, other alternatives are being suggested for medical management of this disease. The efficacy of these alternatives remains unclear.

Antioxidant Therapy in Graves' Orbitopathy

The balance of the cell redox state is a key point for the maintenance of cellular homeostasis. Increased reactive oxygen species (ROS) generation leads to oxidative damage of tissues, which is involved in the development of several diseases, including autoimmune diseases. Graves' Orbitopathy (GO) is a disfiguring autoimmune-related condition associated with Graves' Disease (GD). Patients with active, moderate-to-severe GO, are generally treated with high doses intravenous glucocorticoids (ivGCs) and/or orbital radiotherapy. On the contrary, up to recently, local ointments were the treatment most frequently offered to patients with mild GO, because the risks related to ivGCs does not justify the relatively poor benefits expected in mild GO. However, a medical treatment for these patients is heavily wanted, considering that GO can progress into more severe forms and also patients with mild GO complain with an impairment in their quality of life. Thus, based on the role of oxidative stress in the pathogenesis of GO, a therapy with antioxidant agents has been proposed and a number of studies have been performed, both in vitro and in vivo, which is reviewed here.

Will biological agents supplant systemic glucocorticoids as the first-line treatment for thyroid-associated ophthalmopathy?

In this article, the two authors present their opposing points of view concerning the likelihood that glucocorticoids will be replaced by newly developed biological agents in the treatment of active, moderate-to-severe thyroid-associated ophthalmopathy (TAO). TAO is a vexing, disfiguring and potentially blinding autoimmune manifestation of thyroid autoimmunity. One author expresses the opinion that steroids are nonspecific, frequently fail to improve the disease and can cause sometimes serious side effects. He suggests that glucocorticoids should be replaced as soon as possible by more specific and safer drugs, once they become available. The most promising of these are biological agents. The other author argues that glucocorticoids are proven effective and are unlikely to be replaced by biologicals. He reasons that while they may not uniformly result in optimal benefit, they have been proven effective in many reports. He remains open minded about alternative therapies such as biologicals but remains skeptical that they will replace steroids as the first-line therapy for active, moderate-to-severe TAO without head-to-head comparative clinical trials demonstrating superiority. Despite these very different points of view, both authors are optimistic about the availability of improved medical therapies for TAO, either as single agents or in combination. Further, both agree that better treatment options are needed to improve the care of our patients with active moderate-to-severe TAO.

Association of T and B Cells Infiltrating Orbital Tissues With Clinical Features of Graves Orbitopathy

Importance

Graves orbitopathy (GO) responds to immunosuppressive treatments when clinically active but poorly when inactive. In other autoimmune diseases, response has been ascribed to a reduction in lymphocytes infiltrating the target organ. It is not known whether active vs inactive GO differs in this regard, which would help in understanding the link between GO immunologic features and clinical behavior.

Objective

To investigate the association between orbital lymphocytic infiltrate and GO clinical features.

Design, Setting, and Participants

A cohort study aimed at assessing the extent and immunohistochemical phenotype of orbital lymphocytes and associating it with the ophthalmologic features of GO, especially its clinical activity score (CAS), was conducted at a tertiary referral center. Twenty consecutive patients with GO who underwent orbital decompression were included. The study was conducted from January 1 to May 31, 2017.

Exposures

Orbital tissue histology and immunohistochemistry testing as well as ophthalmologic evaluation.

Main Outcomes and Measures

Association between CAS and orbital lymphocytes, analyzed as total number of lymphocytes and main lymphoid subsets.

Results

The patient population included 8 men and 12 women, all of white race, with a mean (SD) age of 46 (13) years. With an established cutoff value of 300 lymphoid cells per tissue sample, lymphocytes above this value were found in orbital tissues of 9 of 20 patients (45%), often organized into distinct foci. The lymphocytes comprised a mixture of T (CD3-positive) and B (CD20-positive) cells, suggesting a mature, polyclonal autoimmune response. In a simple linear regression model, the total number of lymphocytes, as well as the number of CD3- and CD20-positive subsets, correlated with CAS (R = 0.63; 95% CI, 0.27-0.84; P = .003; R = 0.59; 95% CI, 0.20-0.82; P = .006; and R = 0.65; 95% CI, 0.30-0.85; P = .002, respectively). In a multiple linear regression model, lymphocytes maintained their effect on CAS when adjusted for 2 additional variables that were correlated with CAS-smoking and GO duration-highlighting even more the important role of orbital lymphocytes in affecting CAS (total number: R = 0.58; 95% CI, 0.18-0.82; P = .01; CD3-positive: R = 0.58; 95% CI, 0.17-0.82; P = .01; and CD20-positive: R = 0.59; 95% CI, 0.19-0.83; P = .01).

Conclusions and Relevance

This study shows a correlation between T and B lymphocytes infiltrating orbital tissues and the activity of GO, possibly enhancing our understanding of the association between GO immunologic features and clinical expression.

Fingolimod Improves the Outcome of Experimental Graves' Disease and Associated Orbitopathy by Modulating the Autoimmune Response to the Thyroid-Stimulating Hormone Receptor

Graves' disease (GD) and Graves' orbitopathy are associated with stimulating thyrotropin receptor (TSHR) autoantibodies and autoreactive T cells. Recent in vitro studies suggested that sphingosine-1-phosphate (S1P) signaling is involved in the pathogenesis of orbitopathy. In this study, we explored the immune modulatory potential of S1P receptor antagonist fingolimod in a murine model for GD. Fingolimod was orally administered preventively during disease onset or therapeutically after disease onset. Administration of fingolimod during disease onset completely prevented the formation of TSHR-stimulating autoantibodies. Intervention after disease onset rarely reduced TSHR-stimulating autoantibodies and blocking autoantibodies were induced in some animals. Consequently, autoimmune hyperthyroidism characterized by elevated serum thyroxin levels, hyperplastic thyroid morphology accompanied by T cell infiltration, weight gain, enhanced body temperature, and tachycardia did not manifest preventively and showed milder manifestation in therapeutically treated animals. Importantly, examination of orbital tissue showed significant amelioration of orbitopathy manifestations through reduction of T cell infiltration, adipogenesis, and hyaluronan deposition. Autoimmune hyperthyroidism and orbitopathy were accompanied by changes in peripheral and splenic T cell proportions with high CD3⁺, CD4⁺, and CD8⁺ T cells. Activated T cells CD4⁺CD25⁺ were elevated whereas regulatory T cells CD4⁺Foxp3⁺ cells remained unchanged in spleens. Fingolimod decreased elevated T cell levels and increased CD4⁺CD25⁺Foxp3⁺ regulatory T cell populations. Analysis of total disease outcome revealed that treatment during disease onset protected animals against autoimmune hyperthyroidism and orbitopathy. Of note, therapeutic intervention after disease onset suppressed disease in half of the animals and in the other half disease remained at mild stages. The results of this study support a clinical trial to investigate the immunologic and clinical benefits of early treatment with S1P-based drugs in GD.

Zirconium-89-labelled rituximab PET-CT in orbital inflammatory disease

Background

Orbital inflammatory diseases are a heterogenic group of conditions that often entail a difficult diagnostic process and many patients are treatment resistant. Inflammatory diseases can be visualized by Zirconium-89-labelled rituximab PET-CT (⁸⁹Zr-rituximab PET/CT). In this study, we describe our experience and possible potential of the ⁸⁹Zr-rituximab PET/CT for diagnostic and therapeutic management of refractory orbital inflammation.

Results

Retrospectively, ⁸⁹Zr-rituximab uptake was assessed and related to clinical data. The main outcome measures were the characteristics of the scan and the clinical relation of uptake with the diagnostic process and treatment effectivity. Twelve patients with thyroid eye disease (TED) and suspected idiopathic orbital inflammation (IOI) were scanned. Six patients had a strong ⁸⁹Zr-rituximab uptake and showed a focal distribution within the lesion. Four patients (one TED, three IOI) responded well to rituximab treatment after a positive scan. ⁸⁹Zr-rituximab PET/CT was essential to the diagnosis of optic nerve meningioma in one patient.

Conclusion

⁸⁹Zr-rituximab PET/CT has the potential to be a powerful tool for the detection of B cell-mediated disease within the orbit and ocular adnexa. This technique can be a valuable addition for diagnosing diseases around the eye and can potentially predict rituximab treatment response in patients with refractory inflammation.

Treatment strategies for Graves’ ophthalmopathy: a network meta-analysis

Purpose

Various treatments have been investigated for Graves’ ophthalmopathy (GO). We aimed to provide an overall profile of the efficacy and tolerability of various interventions for active and moderate to severe GO.

Methods

PubMed, Embase and the Cochrane Central Register of Controlled Trials were searched on 6 July 2018. Randomised controlled trials (RCT) investigating GO treatments were included. Two researchers independently extracted data according to a predefined form. A random effects network meta-analysis was performed using a frequentist approach. The primary outcome was efficacy, and the secondary outcome was tolerability (side effect discontinuation).

Results

Thirty-three studies with 1846 patients with GO were included. Orbital radiotherapy (ORT) plus intravenous glucocorticoids (IVGC) (OR 27.11; 95% CI 4.57 to 160.92), mycophenolate mofetil (MMF) (24.40, 95% CI 5.28 to 112.67), oral glucocorticoids (OGC) plus ciclosporin (20.22, 95% CI 1.60 to 255.20), IVGC plus MMF (12.08, 95% CI 2.96 to 49.35), teprotumumab (8.92, 95% CI 2.51 to 31.77), ORT plus OGC (4.88, 95% CI 1.25 to 19.06), rituximab (RTX) (4.85, 95% CI 1.18 to 19.86), somatostatin analogues (4.23, 95% CI 1.60 to 11.16), OGC plus azathioprine (AzA) (5.77, 95% CI 1.17 to 28.47) and IVGC (4.96, 95% CI 1.96 to 12.55) showed significantly better improvement than no treatment. ORT plus IVGC ranked first, followed by MMF. High heterogeneity and significant local inconsistency were observed in the RTX studies. The results of the sensitivity analyses were similar to those of the main analysis.

Conclusion

A robust recommendation regarding the best treatment cannot be made, because most evidence was rated as low or very low quality according to the Grading of Recommendations, Assessment, Development and Evaluations framework. Large RCTs and individual participant data meta-analyses are necessary to confirm these results and explore potential moderators.

PROPERO trial registration number

CRD42018103029.

Early low-dose rituximab for active thyroid eye disease: An effective and well-tolerated treatment

BACKGROUND

Thyroid eye disease (TED) is an autoimmune inflammatory disease that can be disfiguring and potentially sight threatening. Suppression of inflammation in active disease can reduce the risk of visual loss and limit long-term sequelae. Current management involves inflammation suppression using glucocorticoids. The aim of this study was to evaluate the efficacy of early disease intervention with targeted immunomodulatory therapy to alter disease course. This paper reports the efficacy of low-dose rituximab in reducing clinical activity in TED in a small population.

METHODS

A retrospective audit of consecutive patients with active TED managed primarily with a 100 mg rituximab infusion. Further glucocorticoid or steroid-sparing agents were prescribed if clinically indicated. Clinical activity score, VISA overall severity score and Oxford Quality of Life score were recorded at each visit as well as TSH receptor antibody levels (TRAb), B cell subsets and adverse reactions.

RESULTS

Twelve patients had mean follow-up of 6.3 months. Clinical activity scores significantly decreased (mean score 5.08 to 1.58; P < 0.001), VISA overall severity scores reduced by 50% from 12 to 6, P < 0.001 and the mean cumulative dose of IV methylprednisolone was 2.3 g. 100 mg rituximab induced significant CD19⁺ B cell depletion (n = 8, P < 0.001). There was no significant reduction in serum TRAb (n = 8, P = 0.06). A transient infusion-related rash was the only adverse effect, n = 4. QoL scores did not differ markedly before and after treatment.

CONCLUSION

Low-dose rituximab is an efficacious, well-tolerated and safe treatment for active TED; reducing disease activity and allowing reduced administration of systemic steroid.

The effects of Rituximab on Graves'orbitopathy: A retrospective study of 14 patients

PURPOSE

Management of Graves' ophthalmopathy remains challenging. Over the last decade, previous studies have shown promising results for Rituximab in the treatment of Graves' ophthalmopathy. We present the response of 14 individuals with active moderate-to-severe Graves' ophthalmopathy to Rituximab, representing one of the largest retrospective case series reported to date.

METHODS

Rituximab was administered intravenously, 1000 mg twice at a 2-week interval. The primary end point was a clinical activity score reduction (improvement by ⩾ 2 points or disease inactivation: clinical activity score < 3) at 24 weeks. Secondary end points included clinical activity score improved by ⩾ 2 points or inactivation of Graves' ophthalmopathy at 12 weeks, improvement in each item of the clinical activity score, in proptosis, in severity disease by the total eye score and in diplopia according to the Gorman score.

RESULTS

A limited improvement in clinical activity score was observed (median improvement at 24 weeks by 1 point, p = 0.002, (5/14 patients, 35.7%). Disease inactivation occurred in 50% of patients (7/14 patients). At 12 weeks, clinical activity score improved by ⩾ 2 points in 2/14 patients (14.3%) and inactivation of Graves' ophthalmopathy occurred in four patients (28.6%). Improvement in proptosis and total eye score was observed in 3/9 patients (33%) and in 4/14 patients (28.6%) at 24 weeks, respectively. Only one patient experienced moderate adverse event.

CONCLUSION

Rituximab is a well-tolerated treatment with a good safety profile, but offered limited and partial improvement for active moderate-to-severe Graves' ophthalmopathy with a long duration of disease.

Current and Emerging Treatment Strategies for Graves' Orbitopathy

Graves' orbitopathy is a debilitating disorder which occurs in patients with autoimmune thyroid disease, mainly Graves' disease, and adds layers of complexity to management of both conditions. We conducted a comprehensive review of literature for publications relating to established and new management options for Graves' orbitopathy and have summarized key articles in this review. Initial evaluation of patients with Graves' disease should also include clinical evaluation for orbitopathy. If eye disease is present, patients are best managed by a multi-specialty team including an endocrinologist and ophthalmologist. All patients with Graves' orbitopathy benefit from risk factor modification and normalization of thyroid function tests. Patients with active, mild disease generally benefit from local therapies and selenium, while patients with moderate-to-severe disease usually require the addition of intravenous glucocorticoid therapy. If there is an inadequate response to glucocorticoid therapy, several second-line therapies have been investigated for use, including orbital radiotherapy (with additional glucocorticoids), rituximab, cyclosporine, mycophenolate mofetil, and methotrexate. Use of new biologic agents, mainly teprotumumab and tocilizumab, have demonstrated impressive reductions in disease activity and severity. If these results are confirmed, the treatment paradigm is likely to change in the future. Finally, there are several novel immunotherapies being investigated for Graves' disease, which may have treatment implications for Graves' orbitopathy as well. Overall, there are many encouraging advances in the therapy of Graves' orbitopathy that are making the future more promising for patients suffering from this disease.