Does rituximab improve clinical outcomes of patients with thyroid-associated ophthalmopathy? A systematic review and meta-analysis

Potential role of IGF-1R in the interaction between orbital fibroblasts and B lymphocytes: an implication for B lymphocyte depletion in the active inflammatory phase of thyroid-associated ophthalmopathy

BACKGROUND

Thyroid eye disease (TED) is an inflammatory process involving lymphocyte-mediated immune response and orbital tissue damage. The anti-insulin-like growth factor-1 receptor (IGF-1R) antibodies produced by B lymphocytes are involved in the activation of orbital fibroblasts and the inflammatory process of orbital tissue damage in TED. The purpose of this study was to explore the role of IGF-1R in the mechanistic connection between orbital fibroblasts and B lymphocytes in TED.

METHODS

Orbital fibroblasts sampled from orbital connective tissues and peripheral B lymphocytes isolated from peripheral blood, which were obtained from 15 patients with TED and 15 control patients, were co-cultured at a ratio of 1:20. The level of IGF-1R expression in orbital fibroblasts was evaluated by flow cytometry and confocal microscopy. Transient B lymphocyte depletion was induced with anti-CD20 monoclonal antibody rituximab, while the IGF-1R pathway was blocked by the IGF-1R binding protein. The expression levels of interleukin-6 (IL-6) and regulated upon activation, normal T cell expressed and secreted (RANTES) in the co-culture model were quantified via ELISA.

RESULTS

IGF-1R expression was significantly elevated in TED orbital fibroblasts compared to that of controls. A 24-h co-culture of orbital fibroblasts with peripheral B lymphocytes induced elevated expression levels of IL-6 and RANTES in each group (TED patients and controls), with the highest levels occurring in TED patients (T + T group). Rituximab and IGF-1R binding protein significantly inhibited increased levels of IL-6 and RANTES in the co-culture model of TED patients.

CONCLUSIONS

IGF-1R may mediate interaction between orbital fibroblasts and peripheral B lymphocytes; thus, blocking IGF-1R may reduce the local inflammatory response in TED. Rituximab-mediated B lymphocyte depletion played a role in inhibiting inflammatory responses in this in vitro co-culture model, providing a theoretical basis for the clinical application of anti-CD20 monoclonal antibodies in TED.

Monoclonal antibodies for the treatment of Graves' ophthalmopathy: A systematic review and meta-analysis

PURPOSE

The traditional standard of care for Graves' ophthalmopathy (GO) is glucocorticoid therapy, which is associated with many long-term side effects. The aim of this systematic review and meta-analysis was to compare the traditional therapy to novel monoclonal antibodies (e.g. rituximab [RTX], teprotumumab, and tocilizumab [TCZ]).

METHODS

We searched the Medline, Embase, and Cochrane Central Register of Controlled Trials databases. We included randomized controlled trials (RCTs) that compared different monoclonal antibodies (e.g. RTX, teprotumumab, and TCZ) with glucocorticoids or placebo in patients with GO. We evaluated the clinical activity score (CAS), proptosis, subjective diplopia using the Gorman score, quality of life (QoT), adverse events, change in lid fissure, NOSPECS score, and TSH receptor antibody (TRAb) levels. The odds ratio (OR) was used to represent dichotomous outcomes. The continuous outcomes were represented as standardized mean difference (SMD). Data were pooled using the inverse variance weighting method. Risk of bias was assessed using the revised Cochrane risk-of-bias tool for randomized trials.

RESULTS

Six (n = 571) RCTs were deemed eligible. The different monoclonal antibodies were significantly more efficacious than glucocorticoid/placebo in terms of reduction in CAS (SMD = -1.44, 95% confidence interval (CI): -1.91--0.97, P < 0.00001, I² = 74%), change in proptosis (SMD = -4.96, 95% CI: -8.02--1.89, P = 0.002, I² = 99%), QoL (SMD = 2.64, 95% CI: 0.50-4.79, P = 0.02, I² = 97%), and Gorman score for diplopia (OR = 3.42, 95% CI: 1.62-7.22, P = 0.001, I² = 8%). However, monoclonal antibodies have shown higher rates of adverse events (OR = 2.91, 95% CI: 1.12-7.56, P = 0.03, I² = 62%). No significant difference was found with respect to lid fissure, NOSPECS, and TRAb levels.

CONCLUSION

This meta-analysis demonstrated that monoclonal antibodies were associated with more favorable clinical outcomes than standard steroid therapy or placebo, especially with regard to CAS, change in proptosis, diplopia, and QoL, with teprotumumab being superior. In addition, only minor safety concerns were identified with monoclonal antibodies though less worrisome than using traditional steroids.

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.

2022 Update on Clinical Management of Graves Disease and Thyroid Eye Disease

The management of hyperthyroidism and extrathyroidal manifestations of Graves disease remains complex. Considerations that include patient preference, age, comorbidity, pregnancy, tobacco smoking, and social determinants of health must all be weaved into a cohesive management plan. A multidisciplinary team is required to manage all aspects of Graves disease, particularly thyroid eye disease, for which new therapeutic options are now available.

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.

[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.

B Cells and Antibodies as Targets of Therapeutic Intervention in Neuromyelitis Optica Spectrum Disorders

The first description of neuromyelitis optica by Eugène Devic and Fernand Gault dates back to the 19th century, but only the discovery of aquaporin-4 autoantibodies in a major subset of affected patients in 2004 led to a fundamentally revised disease concept: Neuromyelits optica spectrum disorders (NMOSD) are now considered autoantibody-mediated autoimmune diseases, bringing the pivotal pathogenetic role of B cells and plasma cells into focus. Not long ago, there was no approved medication for this deleterious disease and off-label therapies were the only treatment options for affected patients. Within the last years, there has been a tremendous development of novel therapies with diverse treatment strategies: immunosuppression, B cell depletion, complement factor antagonism and interleukin-6 receptor blockage were shown to be effective and promising therapeutic interventions. This has led to the long-expected official approval of eculizumab in 2019 and inebilizumab in 2020. In this article, we review current pathogenetic concepts in NMOSD with a focus on the role of B cells and autoantibodies as major contributors to the propagation of these diseases. Lastly, by highlighting promising experimental and future treatment options, we aim to round up the current state of knowledge on the therapeutic arsenal in NMOSD.

Differential Effects of MS Therapeutics on B Cells-Implications for Their Use and Failure in AQP4-Positive NMOSD Patients

B cells are considered major contributors to multiple sclerosis (MS) pathophysiology. While lately approved disease-modifying drugs like ocrelizumab deplete B cells directly, most MS medications were not primarily designed to target B cells. Here, we review the current understanding how approved MS medications affect peripheral B lymphocytes in humans. These highly contrasting effects are of substantial importance when considering these drugs as therapy for neuromyelitis optica spectrum disorders (NMOSD), a frequent differential diagnosis to MS, which is considered being a primarily B cell- and antibody-driven diseases. Data indicates that MS medications, which deplete B cells or induce an anti-inflammatory phenotype of the remaining ones, were effective and safe in aquaporin-4 antibody positive NMOSD. In contrast, drugs such as natalizumab and interferon-β, which lead to activation and accumulation of B cells in the peripheral blood, lack efficacy or even induce catastrophic disease activity in NMOSD. Hence, we conclude that the differential effect of MS drugs on B cells is one potential parameter determining the therapeutic efficacy or failure in antibody-dependent diseases like seropositive NMOSD.

Role of a new bioassay for thyroid-stimulating antibodies (aequorin TSAb) in Graves' ophthalmopathy

Graves' ophthalmopathy (GO) is characterized by an autoimmune reaction against thyrotropin (TSH) receptors and is diagnosed by TSH receptor antibody (TRAb). A novel assay for thyroid-stimulating antibody (TSAb) was recently introduced using a frozen Chinese hamster ovary cell line expressing TSH receptors, cyclic adenosine monophosphate (cAMP)-gated calcium channel, and aequorin (aequorin TSAb). The aim of this study was to evaluate the role of aequorin TSAb in GO. We studied 136 Japanese patients with GO (22 euthyroid and 8 hypothyroid GO patients) at our hospital. TRAbs were estimated by first generation TRAb (TRAb 1^st), second generation TRAb (hTRAb 2^nd), conventional porcine TSAb, and the new aequorin TSAb assays. Aequorin TSAb, porcine TSAb, TRAb 1^st, and hTRAb 2^nd were positive in 125/136 (92%), 110/136 (81%), 81/130 (62%), and 93/114 (82%) patients, respectively. In patients with hyperthyroid GO, they were positive in 98/106 (98%), 96/106 (91%), 78/101 (77%), and 84/93 (90%) patients, respectively. In patients with euthyroid GO, they were positive in 19/22 (86%), 9/22 (41%), 1/21 (5%), and 6/17 (35%) patients, respectively. Aequorin TSAb levels were significantly related to TRAb 1^st (r = 0.4172, p < 0.0001), hTRAb 2^nd (r = 0.2592, p < 0.0001), and porcine TSAb (r = 0.4665, p < 0.0001). Clinical activity score (CAS) was significantly greater in patients with high titers of aequorin TSAb than in those with low titers. Aequorin TSAb levels were significantly related to the signal intensity ratio of the enlarged eye muscle and proptosis evaluated by MRI before steroid pulse therapy. Aequorin TSAb assay was more sensitive than the conventional assays, especially in euthyroid GO.

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.

Fibroblast Growth Factor Receptor Inhibitors Reduce Adipogenesis of Orbital Fibroblasts and Enhance Myofibroblastic Differentiation in Graves' Orbitopathy

Purpose: Orbital fibroblasts are involved in pathogenesis of Graves' orbitopathy (GO). Fibroblast growth factor (FGF) affects fibroblasts of GO. This study aims to investigate the roles of FGF and FGF receptor (FGFR) in GO.Methods: Serum FGF proteins and orbital fibroblast FGFR proteins and mRNAs were measured in GO patients and controls. Orbital fibroblasts of GO were cultured and accessed for changes in proliferation (by nuclei number and MTT), myofibroblastic differentiation (by α-SMA), and adipogenesis (by oil droplets using Oil Red O stain) under FGF1 with or without FGFR inhibitors (FGFRi).Results: Serum FGF1 and FGF2 were increased in GO patients. FGFR1 was the most abundantly expressed FGFR in GO orbital fibroblasts. FGF1 increased GO fibroblast proliferation/adipogenesis and suppressed myofibroblastic differentiation, while FGFRi reversed these effects.Conclusion: FGF signaling may be involved in GO pathogenesis. Manipulation of FGF-FGFR pathway for GO treatment is worthy of further investigation.Registration number on Clinicaltrials.gov: NCT03324022.

Adjuvant rituximab, a potential treatment for the young patient with Graves' hyperthyroidism (RiGD): study protocol for a single-arm, single-stage, phase II trial

INTRODUCTION

Graves' disease (Graves' hyperthyroidism) is a challenging condition for the young person and their family. The excess thyroid hormone generated by autoimmune stimulation of the thyroid stimulating hormone receptor on the thyroid gland can have a profound impact on well-being. Managing the young person with Graves' hyperthyroidism is more difficult than in older people because the side effects of conventional treatment are more significant in this age group and because the disease tends not to resolve spontaneously in the short to medium term. New immunomodulatory agents are available and the anti-B cell monoclonal antibody rituximab is of particular interest because it targets cells that manufacture the antibodies that stimulate the thyroid gland in Graves'.

METHODS AND ANALYSIS

The trial aims to establish whether the combination of a single dose of rituximab (500 mg) and a 12-month course of antithyroid drug (usually carbimazole) can result in a meaningful increase in the proportion of patients in remission at 2 years, the primary endpoint. A single-stage, phase II A'Hern design is used. 27 patients aged 12-20 years with newly presenting Graves' hyperthyroidism will be recruited. Markers of immune function, including lymphocyte numbers and antibody levels (total and specific), will be collected regularly throughout the trial.

DISCUSSION

The trial will determine whether the immunomodulatory medication, rituximab, will facilitate remission above and beyond that observed with antithyroid drug alone. A meaningful increase in the expected proportion of young patients entering remission when managed according to the trial protocol will justify consideration of a phase III trial.Ethics and dissemination The trial has received a favourable ethical opinion (North East - Tyne and Wear South Research Ethics Committee, reference 16/NE/0253, EudraCT number 2016-000209-35). The results of this trial will be distributed at international endocrine meetings, in the peer-reviewed literature and via patient support groups.

TRIAL REGISTRATION NUMBER

ISRCTN20381716.

Tocilizumab for the Management of Corticosteroid-Resistant Mild to Severe Graves' Ophthalmopathy, a Report of Three Cases

Purpose: To discuss the use of tocilizumab in mild to severe Graves' ophthalmopathy as corticosteroid-adjunctive therapy. Methods: Retrospective case reports.Results: Three patients with corticosteroid-resistant or advanced diplopia-associated Graves' ophthalmopathy were subsequently treated with monthly intravenous tocilizumab at a dose of 8 mg/kg. None reported a past or present history of dysthyroidism. The adjunction of interleukin-6-receptor monoclonal antibody treatment was associated with a significant improvement in ocular symptoms, notably diplopia and proptosis, and functional prognosis in all patients, with one relapse approximately two months after the end of the treatment.Conclusion: These clinical reports confirm the relative efficacy and tolerability profile of intravenous tocilizumab in severe or corticosteroid-resistant Graves' ophthalmopathy.

Thyroid eye disease: what is new to know?

PURPOSE OF REVIEW

The pathophysiology of thyroid eye disease (TED) is still not fully understood. However, recently described risk factors and molecular findings have brought new insights into the mechanisms of TED and could lead to the emerging use of more targeted therapies. This article aims to review the clinical findings of TED, and the most recent advances in our understanding of the risk factors and therapeutic options for TED.

RECENT FINDINGS

Smoking has been recently shown to have an impact on specific gene expression involved in several disease-related pathways, which seems to be reversible with smoking cessation. This finding further emphasizes the importance of smoking cessation in the prevention and treatment of TED. Selenium deficiency and high-serum cholesterol have been described to be potential independent risk factors for TED and their management could decrease the incidence and severity of TED. In terms of therapeutic options, immunomodulatory medications have shown some promising results for disease control in TED over the past years, but further randomized prospective studies with larger sample sizes are still needed to prove their efficacy. A new technique of P brachytherapy was shown to have quick therapeutic effects on TED without significant side effects and could be a promising therapy for selected cases of TED.

SUMMARY

TED is one of the most common autoimmune inflammatory disorders of the orbit. Although its pathophysiology remains unclear, newly described genetic findings and risk factors could help in explaining its occurrence and guide future therapies. Immunosuppressant medications are increasingly used in the management of TED, but further studies are needed to confirm their effectiveness.