Safety and efficacy of tocilizumab versus azathioprine in highly relapsing neuromyelitis optica spectrum disorder (TANGO): an open-label, multicentre, randomised, phase 2 trial

Autoantigen-specific CD4+ T cells acquire an exhausted phenotype and persist in human antigen-specific autoimmune diseases

Pro-inflammatory autoantigen-specific CD4+ T helper (auto-Th) cells are central orchestrators of autoimmune diseases (AIDs). We aimed to characterize these cells in human AIDs with defined autoantigens by combining human leukocyte antigen (HLA)-tetramer-based and activation-based multidimensional ex vivo analyses. In aquaporin4-antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD) patients, auto-Th cells expressed CD154, but proliferative capacity and pro-inflammatory cytokines were strongly reduced. Instead, exhaustion-associated co-inhibitory receptors were expressed together with FOXP3, the canonical regulatory T cell (Treg) transcription factor. Auto-Th cells responded in vitro to checkpoint inhibition and provided potent B cell help. Cells with the same exhaustion-like (ThEx) phenotype were identified in soluble liver antigen (SLA)-antibody-autoimmune hepatitis and BP180-antibody-positive bullous pemphigoid, AIDs of the liver and skin, respectively. While originally described in cancer and chronic infection, our data point to T cell exhaustion as a common mechanism of adaptation to chronic (self-)stimulation across AID types and link exhausted CD4+ T cells to humoral autoimmune responses, with implications for therapeutic targeting.

NMOSD and MOGAD: an evolving disease spectrum

Neuromyelitis optica (NMO) spectrum disorder (NMOSD) is a relapsing inflammatory disease of the CNS, characterized by the presence of serum aquaporin 4 (AQP4) autoantibodies (AQP4-IgGs) and core clinical manifestations such as optic neuritis, myelitis, and brain or brainstem syndromes. Some people exhibit clinical characteristics of NMOSD but test negative for AQP4-IgG, and a subset of these individuals are now recognized to have serum autoantibodies against myelin oligodendrocyte glycoprotein (MOG) - a condition termed MOG antibody-associated disease (MOGAD). Therefore, the concept of NMOSD is changing, with a disease spectrum emerging that includes AQP4-IgG-seropositive NMOSD, MOGAD and double-seronegative NMOSD. MOGAD shares features with NMOSD, including optic neuritis and myelitis, but has distinct pathophysiology, clinical profiles, neuroimaging findings (including acute disseminated encephalomyelitis and/or cortical encephalitis) and biomarkers. AQP4-IgG-seronegative NMOSD seems to be a heterogeneous condition and requires further study. MOGAD can manifest as either a monophasic or a relapsing disease, whereas NMOSD is usually relapsing. This Review summarizes the history and current concepts of NMOSD and MOGAD, comparing epidemiology, clinical features, neuroimaging, pathology and immunology. In addition, we discuss new monoclonal antibody therapies for AQP4-IgG-seropositive NMOSD that target complement, B cells or IL-6 receptors, which might be applied to MOGAD in the near future.

Chimeric antigen receptor T-cell therapy for autoimmune diseases of the central nervous system: a systematic literature review

IMPORTANCE

B-cell-targeting monoclonal antibodies have demonstrated safety and efficacy in multiple sclerosis or anti-aquaporin-4 IgG positive neuromyelitis optica spectrum disorder. However, these therapies do not facilitate drug-free remission, which may become possible with cell-based therapies, including chimeric antigen receptor (CAR) T cells. CAR T-cell therapy holds promise for addressing other antibody-mediated CNS disorders, e.g., MOG-associated disease or autoimmune encephalitis.

OBJECTIVE

To provide an overview of the current clinical knowledge on CAR T-cell therapy in central nervous system autoimmunity.

EVIDENCE REVIEW

We searched PubMed, Embase, Google Scholar, PsycINFO, and clinicaltrials.gov using the terms 'CAR T cell' and 'multiple sclerosis/MS' or 'neuromyelitis optica/spectrum diseases/NMOSD' or 'MOG-associated disease/MOGAD 'or' autoimmune encephalitis' or 'neuroimmunology'.

FINDINGS

An ongoing phase I clinical trial has indicated the safety and benefits of anti-BCMA CAR T cells in 12 patients with AQP4-IgG seropositive neuromyelitis optica spectrum disorder. Case reports involving two individuals with progressive multiple sclerosis and one patient with stiff-person syndrome demonstrated a manageable safety profile following treatment with anti-CD19 CAR T cells. Recruitment has commenced for two larger studies in MS, and a phase I open-label basket study is underway to evaluate BCMA-directed CAR T cells in various antibody-associated inflammatory diseases, including MOG-associated disease. Preclinical research on NMDA receptor antibody autoimmune encephalitis treated with chimeric autoantibody receptor T cells generated promising data.

CONCLUSIONS AND RELEVANCE

There is minimal evidence of the benefits of CAR T-cell therapy in individuals with central nervous system-directed autoimmunity. Nevertheless, multicenter controlled clinical trials with a manageable safety profile appear feasible and are warranted due to very promising case experiences.

Targeting cytokine networks in neuroinflammatory diseases

In neuroinflammatory diseases, systemic (blood-borne) leukocytes invade the central nervous system (CNS) and lead to tissue damage. A causal relationship between neuroinflammatory diseases and dysregulated cytokine networks is well established across several preclinical models. Cytokine dysregulation is also observed as an inadvertent effect of cancer immunotherapy, where it often leads to neuroinflammation. Neuroinflammatory diseases can be separated into those in which a pathogen is at the centre of the immune response and those of largely unknown aetiology. Here, we discuss the pathophysiology, cytokine networks and therapeutic landscape of 'sterile' neuroinflammatory diseases such as multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), neurosarcoidosis and immune effector cell-associated neurotoxicity syndrome (ICANS) triggered by cancer immunotherapy. Despite successes in targeting cytokine networks in preclinical models of neuroinflammation, the clinical translation of targeting cytokines and their receptors has shown mixed and often paradoxical responses.

Predictors of relapse risk and treatment response in AQP4-IgG positive and seronegative NMOSD: A multicentre study

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) can be categorised into aquaporin-4 antibody (AQP4-IgG) NMOSD or seronegative NMOSD. While our knowledge of AQP4-IgG NMOSD has evolved significantly in the past decade, seronegative NMOSD remains less understood. This study aimed to evaluate the predictors of relapses and treatment responses in AQP4-IgG NMOSD and seronegative NMOSD.

METHODS

This was a multicentre, international, retrospective cohort study using the MSBase registry. Recurrent relapse risk was assessed using an Andersen-Gill model and risk of first relapse was evaluated using a Cox proportional hazards model. Covariates that putatively influence relapse risk included demographic factors, clinical characteristics and immunosuppressive therapies; the latter was assessed as a time-varying covariate.

RESULTS

A total of 398 patients (246 AQP4-IgG NMOSD and 152 seronegative NMOSD) were included. The AQP4-IgG NMOSD and seronegative NMOSD patients did not significantly differ by age at disease onset, ethnicity or annualised relapse rate. Both low-efficacy and high-efficacy immunosuppressive therapies were associated with significant reductions in recurrent relapse risk, with notably greater protection conferred by high-efficacy therapies in both AQP4-IgG NMOSD (HR 0.27, 95% CI 0.15 to 0.49, p<0.001) and seronegative NMOSD (HR 0.21, 95% CI 0.08 to 0.51, p<0.001). Longer disease duration (HR 0.97, 95% CI 0.95 to 0.99, p<0.001) and male sex (HR 0.52, 95% CI 0.34 to 0.84, p=0.007) were additional protective variables in reducing the recurrent relapse risk for the AQP4-IgG NMOSD group.

CONCLUSION

Although further studies are needed to improve our understanding of seronegative NMOSD, our findings underscore the importance of aggressive treatment with high-efficacy immunotherapies in both NMOSD subtypes, regardless of serostatus.

Review of the Longitudinal Management of Autoimmune Encephalitis, Potential Biomarkers, and Novel Therapeutics

Purpose of Review

Increasing awareness and earlier diagnosis of autoimmune encephalitis (AE) have led to a greater number of patients being cared for longitudinally by neurologists. Although many neurologists are now familiar with the general approach to diagnosis and acute immunosuppression, this review aims to provide neurologists with guidance related to management beyond the acute phase of disease, including long-term immunosuppression, monitoring, potential biomarkers of disease activity, outcome measures, and symptom management.

Recent Findings

Observational studies in AE have demonstrated that early diagnosis and treatment is associated with improved neurologic outcomes, particularly in AE with antibodies targeting neuronal cell surface/synaptic proteins. The literature regarding long-term management is evolving. In addition to traditional immunosuppressive approaches, there is emerging use of novel immunosuppressive therapies (ISTs) in case series, and several randomized controlled trials are planned. Novel biomarkers of disease activity and methods to measure outcomes and response to treatment are being explored. Furthermore, it is increasingly recognized that many individuals have chronic symptoms affecting quality of life including seizures, cognitive impairment, fatigue, sleep disorders, and mood disorders, and there are emerging data supporting the use of patient centered outcome measures and multidisciplinary symptom-based care.

Summary

This review aims to summarize recent literature and offer a practical approach to long-term management of adult patients with AE through a multidisciplinary approach. We summarize current knowledge on ISTs, potential biomarkers of disease activity, outcome measures, and long-term sequelae. Further research is needed to answer questions regarding optimal IST, biomarker validity, and sequelae of disease.

NMOSD and MOGAD

OBJECTIVE

This article reviews the clinical features, MRI characteristics, diagnosis, and treatment of aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). The main differences between these disorders and multiple sclerosis (MS), the most common demyelinating disease of the central nervous system (CNS), are also highlighted.

LATEST DEVELOPMENTS

The past 20 years have seen important advances in understanding rare demyelinating CNS disorders associated with AQP4 IgG and myelin oligodendrocyte glycoprotein (MOG) IgG. The rapidly expanding repertoire of immunosuppressive agents approved for the treatment of AQP4-NMOSD and emerging as potentially beneficial in MOGAD mandates prompt recognition of these diseases. Most of the recent literature has focused on the identification of clinical and MRI features that help distinguish these diseases from each other and MS, simultaneously highlighting major diagnostic pitfalls that may lead to misdiagnosis. An awareness of the limitations of currently available assays for AQP4 IgG and MOG IgG detection is fundamental for identifying rare false antibody positivity and avoiding inappropriate treatments. For this purpose, diagnostic criteria have been created to help the clinician interpret antibody testing results and recognize the clinical and MRI phenotypes associated with AQP4-NMOSD and MOGAD.

ESSENTIAL POINTS

An awareness of the specific clinical and MRI features associated with AQP4-NMOSD and MOGAD and the limitations of currently available antibody testing assays is crucial for a correct diagnosis and differentiation from MS. The growing availability of effective treatment options will lead to personalized therapies and improved outcomes.

Understanding Autoimmunity: Mechanisms, Predisposing Factors, and Cytokine Therapies

Autoimmunity refers to an organism's immune response against its own healthy cells, tissues, or components, potentially leading to irreversible damage to vital organs. Central and peripheral tolerance mechanisms play crucial roles in preventing autoimmunity by eliminating self-reactive T and B cells. The disruption of immunological tolerance, characterized by the failure of these mechanisms, results in the aberrant activation of autoreactive lymphocytes that target self-tissues, culminating in the pathogenesis of autoimmune disorders. Genetic predispositions, environmental exposures, and immunoregulatory disturbances synergistically contribute to the susceptibility and initiation of autoimmune pathologies. Within the realm of immune therapies for autoimmune diseases, cytokine therapies have emerged as a specialized strategy, targeting cytokine-mediated regulatory pathways to rectify immunological imbalances. Proinflammatory cytokines are key players in inducing and propagating autoimmune inflammation, highlighting the potential of cytokine therapies in managing autoimmune conditions. This review discusses the etiology of autoimmune diseases, current therapeutic approaches, and prospects for future drug design.

Moving towards a new era for the treatment of neuromyelitis optica spectrum disorders

Neuromyelitis optica spectrum disorders (NMOSD) include a rare group of autoimmune conditions that primarily affect the central nervous system. They are characterized by inflammation and damage to the optic nerves, brain and spinal cord, leading to severe vision impairment, locomotor disability and sphynteric disturbances. In the majority of cases, NMOSD arises due to specific serum immunoglobulin G (IgG) autoantibodies targeting aquaporin 4 (AQP4-IgG), which is the most prevalent water-channel protein of the central nervous system. Early diagnosis and treatment are crucial to manage symptoms and prevent long-term disability in NMOSD patients. NMOSD were previously associated with a poor prognosis. However, recently, a number of randomized controlled trials have demonstrated that biological therapies acting on key elements of NMOSD pathogenesis, such as B cells, interleukin-6 (IL-6) pathway, and complement, have impressive efficacy in preventing the occurrence of clinical relapses. The approval of the initial drugs marks a revolutionary advancement in the treatment of NMOSD patients, significantly transforming therapeutic options and positively impacting their prognosis. In this review, we will provide an updated overview of the key immunopathological, clinical, laboratory, and neuroimaging aspects of NMOSD. Additionally, we will critically examine the latest advancements in NMOSD treatment approaches. Lastly, we will discuss key aspects regarding optimization of treatment strategies and their monitoring.

Efficacy and safety of tocilizumab in patients with refractory generalized myasthenia gravis

BACKGROUND

We aimed to compare the efficacy of tocilizumab with conventional immunotherapy in refractory patients with acetylcholine receptor antibody-positive (AChR-Ab+) generalized myasthenia gravis (gMG).

METHODS

This single-center prospective cohort study was based on patients from an MG registry study in China and conducted from February 10, 2021 to March 31, 2022. Adult refractory patients with AChR-Ab+ gMG were assigned to tocilizumab or conventional immunotherapy groups. The primary efficacy outcome was the mean difference of MG activities of daily living (MG-ADL) change at weeks 4, 8, 12, 16, 20, 24 corresponding to that at the baseline between the two groups. A generalized estimating equation model was used for the primary outcome analysis. Safety was assessed based on adverse events.

RESULTS

Of 34 eligible patients, 20 (mean [standard deviation] age, 53.8 [21.9] years; 12 [60.0%] female) received tocilizumab and 14 received conventional immunotherapy (45.8 [18.0] years; 8 [57.1%] female). The tocilizumab group had greater reduction in MG-ADL score at week 4 (adjusted mean difference, -3.4; 95% CI, -4.7 to -2.0; p < 0.001) than the conventional immunotherapy group, with significant differences sustained through week 24 (adjusted mean difference, -4.5; 95% CI, -6.4 to -2.6; p < 0.001). At week 24, the proportion of patients achieving higher levels of MG-ADL (up to 7-point reduction) and QMG (up to 11-point reduction) scores improvement was significantly greater with tocilizumab. Tocilizumab had acceptable safety profiles without severe or unexpected safety issues.

CONCLUSION

Tocilizumab is safe and effective in improving the MG-ADL score and reducing prednisone dose in refractory AChR-Ab+ gMG, suggesting tocilizumab has the potential to be a valuable therapeutic option for such patients.

Neuromyelitis Optica Spectrum Disorders and Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease

For over two centuries, clinicians have been aware of various conditions affecting white matter which had come to be grouped under the umbrella term multiple sclerosis. Within the last 20 years, specific scientific advances have occurred leading to more accurate diagnosis and differentiation of several of these conditions including, neuromyelitis optica spectrum disorders and myelin oligodendrocyte glycoprotein antibody disease. This new understanding has been coupled with advances in disease-modifying therapies which must be accurately applied for maximum safety and efficacy.

Responsiveness to Tocilizumab in Anti-Acetylcholine Receptor-Positive Generalized Myasthenia Gravis

Tocilizumab, a humanized IL-6R monoclonal antibody, has been used in autoimmune diseases closely related to humoral immunity. This report aims to evaluate the efficacy and safety in patients with anti-acetylcholine receptor-positive (AChR+) generalized myasthenia gravis (gMG). We performed a prospective, open-label, single-arm study in patients with gMG in a 48-week follow-up. All patients were AChR+ and were given tocilizumab by intravenous infusion at a dose of 8 mg/kg at intervals of 4 weeks. The primary endpoint was mean change from baseline in quantitative MG (QMG) score at week 12. The secondary endpoints were mean changes from baseline in MG activities of daily living (MG-ADL) score, AChR-ab titers, and the dosage of oral prednisone at week 12. At week 48, QMG, MG-ADL, and the use of prednisone were also evaluated. Fourteen gMG patients were enrolled and all of them completed the study. Tocilizumab treatment started 8 (4-192) months after the onset of gMG. During tocilizumab treatment, the QMG score was significantly decreased from 15.5 (interqualile range, 9-26) at baseline to 4 (0-9) at week 12 (p < 0.001). The change of ADL was decreased from 14.5(11-19) at baseline to 4 (0-19) at week 12 (p < 0.001) and the change of AChR-ab titers from 15 (7.5-19) at baseline to 6.8 (11.6-4.3) at week 12 (p < 0.001). The dosage of prednisone decreased from baseline 60 (20-65) mg/d to 30 (30-50) mg/d at week 12 (p < 0.001). By the end of the study, the QMG score was 2 (0-7) and MG-ADL score was 1.5 (0-6). 12 (85.7%) patients achieved minimal manifestations. 4 (28.6%) patients were able to discontinue prednisone. No patients experienced exacerbation at the end of the study. No serious adverse events were observed during follow-up. Tocilizumab treatment was associated with a good clinical response and safety over a 48-week observation period, as evidenced by significant improvements in QMG and MG-ADL.

Frontiers and future perspectives of neuroimmunology

Neuroimmunology is an interdisciplinary branch of biomedical science that emerges from the intersection of studies on the nervous system and the immune system. The complex interplay between the two systems has long been recognized. Research efforts directed at the underlying functional interface and associated pathophysiology, however, have garnered attention only in recent decades. In this narrative review, we highlight significant advances in research on neuroimmune interplay and modulation. A particular focus is on early- and middle-career neuroimmunologists in China and their achievements in frontier areas of "neuroimmune interface", "neuro-endocrine-immune network and modulation", "neuroimmune interactions in diseases", "meningeal lymphatic and glymphatic systems in health and disease", and "tools and methodologies in neuroimmunology research". Key scientific questions and future directions for potential breakthroughs in neuroimmunology research are proposed.

Predictors of azathioprine and mycophenolate mofetil response in patients with neuromyelitis optica spectrum disorder: A cohort study

BACKGROUND

Relapse rates of 47 % have been reported in patients with neuromyelitis optica (NMOSD) using Azathioprine (AZA) and mycophenolate mofetil (MMF). Prediction of non-responders could help determine which patients are most likely to benefit from newer monoclonal antibody treatments from the outset.

OBJECTIVES

To identify predictors of AZA and MMF treatment response in NMOSD.

METHODS

Multicenter cohort study of NMOSD patients from Brazil and the United Kingdom, treated with AZA and MMF. An unsatisfactory response was defined as one severe or two non-severe attacks in a year. Cox regression was used to identify predictive factors of unsatisfactory response to AZA and MMF.

RESULTS

103 NMOSD patients, mean age 38 years, 83% female, and 65% of Black ethnic group were included. An unsatisfactory IS response was observed in 42% of patients over 2.5 years (IQR 1.0-8.8) years. A severe preceding attack was more common in non-responders (31.1% x 76.7%, p = <0.001). In multivariable analysis, severe attack (RR 3.13; 95 % CI 1.37-7.18, p = 0.007) or higher annualized relapse rate (RR 4.84; 95 % CI 2.01-11.65, p = < 0.001) predicted an unsatisfactory response. Interestingly, Black NMOSD patients had a lower risk of poor response (RR 0.39, 95 % CI 0.17-0.85, p = 0.019).

CONCLUSION

Severe attack and a higher annualized relapse rate before AZA or MMF initiation were associated with an unsatisfactory IS response. In patients with these characteristics, treatment with higher-efficacy drugs should be considered from the outset.

Chimeric AQP4-based immunosorbent for highly-specific removal of AQP4-IgG from blood

Anti-aquaporin-4 autoantibodies (AQP4-IgG) are implicated in the pathogenesis of neuromyelitis optica spectrum disorders (NMOSD), and their removal from the blood circulation is considered to be an effective method for acute treatment. An ideal extracorporeal AQP4-IgG removal system should have high specificity, which means that it can selectively remove AQP4-IgG without affecting normal immunoglobulins. However, the conventional tryptophan immobilized column lacks sufficient specificity and cannot achieve this goal. In this study, we successfully prepared a fusion protein chimeric AQP4, which consists of the complete antigenic epitopes of human AQP4 and the constant region of scaffold protein DARPin. Chimeric AQP4 was expressed and purified from Escherichia coli, and then immobilized on agarose gel as a ligand for selective capture of AQP4-IgG immunosorbent. The prepared immunosorbent had a theoretical maximum adsorption capacity of 20.48 mg/g gel estimated by Langmuir isotherm. In vitro plasma perfusion tests demonstrated that the chimeric AQP4 coupled adsorbent had remarkable adsorption performance, and could eliminate more than 85 % of AQP4-IgG under the gel-to-plasma ratio of 1:50. Moreover, it exhibited high specificity because other human plasma proteins were not adsorbed in the dynamic adsorption experiment. These results suggest that the chimeric AQP4 coupled immunosorbent can provide a new approach for specific immunoadsorption (IA) treatment of NMOSD.

Treatment of neuromyelitis optica spectrum disorder: revisiting the complement system and other aspects of pathogenesis

Neuromyelitis optica spectrum disorder (NMOSD) represents a rare neuroimmunological disease causing recurrent attacks and accumulation of permanent disability in affected patients. The discovery of the pathogenic IgG‑1 antibody targeting a water channel expressed in astrocytes, aquaporin 4, constitutes a milestone achievement. Subsequently, multiple pathophysiological aspects of this distinct disease entity have been investigated. Demyelinating lesions and axonal damage ensue from autoantibodies targeting an astroglial epitope. This conundrum has been addressed in the current disease model, where activation of the complement system as well as B cells and interleukin 6 (IL-6) emerged as key contributors. It is the aim of this review to address these factors in light of novel treatment compounds which reflect these pathophysiological concepts in aiming for attack prevention, thus reducing disease burden in patients with NMOSD.

Measuring the economic burden of neuromyelitis optica spectrum disorder in Colombia

OBJECTIVE

To assess the economic burden of neuromyelitis optica spectrum disorder (NMOSD) in the Colombian context.

METHODS

Analyses were conducted from a societal perspective using the prevalence-based approach. Costs were expressed in 2022 US dollars (1 USD = $3,914.46 COP). Direct medical costs were assessed from a bottom-up approach. Indirect costs included loss of productivity of the patient and their caregivers. The economic burden of NMOSD in Colombia was estimated as the sum of direct and indirect costs.

RESULTS

The direct cost of treating a patient with NMOSD was USD$ 8,149.74 per year. When projecting costs nationwide, NMOSD would cost USD$ 7.2 million per year. Of these costs, 53.5% would be attributed to relapses and 34.4% to pharmacological therapy. Indirect costs potentially attributed to NMOSD in Colombia were estimated at USD$ 1.5 million per year per cohort. Of these, 78% are attributable to loss of patient productivity, mainly due to reduced access to the labor market and premature mortality.

CONCLUSIONS

The NMOSD has a representative economic burden at the patient level, with direct costs, particularly related to relapses and medicines, being the main component of total costs. These findings are useful evidence that requires attention from public policymakers in Colombia.

Updates in NMOSD and MOGAD Diagnosis and Treatment: A Tale of Two Central Nervous System Autoimmune Inflammatory Disorders

Aquaporin-4-IgG positive neuromyelitis optica spectrum disorder (AQP4+NMOSD) and myelin-oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are antibody-associated diseases targeting astrocytes and oligodendrocytes, respectively. Their recognition as distinct entities has led to each having its own diagnostic criteria that require a combination of clinical, serologic, and MRI features. The therapeutic approach to acute attacks in AQP4+NMOSD and MOGAD is similar. There is now class 1 evidence to support attack-prevention medications for AQP4+NMOSD. MOGAD lacks proven treatments although clinical trials are now underway. In this review, we will outline similarities and differences between AQP4+NMOSD and MOGAD in terms of diagnosis and treatment.

Evidence-based management of optic neuritis

PURPOSE OF REVIEW

Optic neuritis can result from several distinct causes, including multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein antibody disease (MOGAD), when not idiopathic. This review discusses evidence-based treatment approaches contingent upon each specific cause of optic neuritis.

RECENT FINDINGS

Current evidence highlights the need for prompt plasmapheresis as adjunct to intravenous methylprednisolone (IVMP) in patients with NMOSD-associated optic neuritis. Recent advances have included a proliferation of novel disease modifying therapies (DMTs) for long-term management of NMOSD and an understanding of how existing therapeutic options can be leveraged to optimally treat MOGAD.

SUMMARY

In acute idiopathic or MS-associated optic neuritis, IVMP hastens visual recovery, though it does not substantially affect final visual outcomes. IVMP and adjunctive plasmapheresis are beneficial in the treatment of NMOSD-associated optic neuritis, with a shorter time-to-treatment associated with a higher likelihood of recovery. The natural history of untreated MOGAD-associated optic neuritis is unclear but treatment with IVMP is near-universal given phenotypic similarities with NMOSD. Long-term immunosuppressive therapy is warranted in patients with NMOSD as well as in patients with MOGAD with poor visual recovery or recurrent attacks.

Monoclonal antibody therapies for aquaporin-4-immunoglobulin G-positive neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein antibody-associated disease

Monoclonal antibody therapies mark the new era of targeted treatment for relapse prevention in aquaporin-4 (AQP4)-immunoglobulin G (IgG)-positive neuromyelitis optica spectrum disorder (AQP4-IgG+NMOSD). For over a decade, rituximab, an anti-CD20 B-cell-depleting agent, had been the most effectiveness treatment for AQP4-IgG+NMOSD. Tocilizumab, an anti-interleukin-6 receptor, was also observed to be effective. In 2019, several randomized, placebo-controlled trials were completed that demonstrated the remarkable efficacy of eculizumab (anti-C5 complement inhibitor), inebilizumab (anti-CD19 B-cell-depleting agent), and satralizumab (anti-interleukin-6 receptor), leading to the Food and Drug Administration (FDA) approval of specific treatments for AQP4-IgG+NMOSD for the first time. Most recently, ravulizumab (anti-C5 complement inhibitor) was also shown to be highly efficacious in an open-label, external-controlled trial. Although only some patients with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) warrant immunotherapy, there is currently no FDA-approved treatment for relapse prevention in MOGAD. Observational studies showed that tocilizumab was associated with a decrease in relapses, whereas rituximab seemed to have less robust effectiveness in MOGAD compared to AQP4-IgG+NMOSD. Herein, we review the evidence on the efficacy and safety of each monoclonal antibody therapy used in AQP4-IgG+NMOSD and MOGAD, including special considerations in children and women of childbearing potential.

Mitoxantrone in NMO Spectrum Disorder in a Large Multicenter Cohort in French Caribbean

BACKGROUND AND OBJECTIVES

Preventing relapses in neuromyelitis Optica spectrum disorder (NMOSD) is a primary goal. New effective molecules are often expensive and not readily available in regions with fragile health systems. Assessing the efficacy and safety of less costly therapeutic alternatives is necessary. We aim to evaluate the efficacy and safety of mitoxantrone (MiTX) in NMOSD.

METHODS

This is an observational, multicenter, open study of 86 NMOSD-treated patients with prospective follow-up over 30 years. The first endpoint was the first relapse at the 96-week follow-up. The secondary endpoints were to evaluate the median delay to relapse, the annualized relapse rate (ARR), and the Expanded Disability Status Scale (EDSS) at 96 weeks of follow-up and to assess risk factors of relapse and the occurrence of severe adverse effects.

RESULTS

At 96-week follow-up, 71% of our patients were relapse-free, and it was 87% when patients were treated with MiTX from the first attack. The ARR dropped from 0.85 (±0.55) to 0.32 (±0.63) (p < 0.001) and EDSS from 4.9 (±2.4) to 4.2 (±2.6) (p < 0.001). AQP4-IgG seropositivity (hazard ratio [HR] 12.3, 95% CI 1.64-91.6, p = 0.015), a delay between the first attack and MiTX ≥24 months (HR 2.76, 95% CI 1.23-6.17, p = 0.014), and a pretreatment ARR ≥1 (HR 2.38, 95% CI 1.05-5.39, p = 0.037) were predictors of relapse. During the entire follow-up, severe secondary adverse events occurred in 3 patients (3.5%).

DISCUSSION

MiTX is an effective and safe treatment for most of our patients, drastically less expensive than new molecules, and could be allowed in NMOSD Afro-descendant patients in geographical areas where access to care is difficult.

Update on the diagnosis and treatment of neuromyelitis optica spectrum disorders (NMOSD) - revised recommendations of the Neuromyelitis Optica Study Group (NEMOS). Part II: Attack therapy and long-term management

This manuscript presents practical recommendations for managing acute attacks and implementing preventive immunotherapies for neuromyelitis optica spectrum disorders (NMOSD), a rare autoimmune disease that causes severe inflammation in the central nervous system (CNS), primarily affecting the optic nerves, spinal cord, and brainstem. The pillars of NMOSD therapy are attack treatment and attack prevention to minimize the accrual of neurological disability. Aquaporin-4 immunoglobulin G antibodies (AQP4-IgG) are a diagnostic marker of the disease and play a significant role in its pathogenicity. Recent advances in understanding NMOSD have led to the development of new therapies and the completion of randomized controlled trials. Four preventive immunotherapies have now been approved for AQP4-IgG-positive NMOSD in many regions of the world: eculizumab, ravulizumab - most recently-, inebilizumab, and satralizumab. These new drugs may potentially substitute rituximab and classical immunosuppressive therapies, which were as yet the mainstay of treatment for both, AQP4-IgG-positive and -negative NMOSD. Here, the Neuromyelitis Optica Study Group (NEMOS) provides an overview of the current state of knowledge on NMOSD treatments and offers statements and practical recommendations on the therapy management and use of all available immunotherapies for this disease. Unmet needs and AQP4-IgG-negative NMOSD are also discussed. The recommendations were developed using a Delphi-based consensus method among the core author group and at expert discussions at NEMOS meetings.

AQUAPORIN-4 (AQP-4) IMMUNOGLOBULIN G SEROPOSITIVE NEUROMYELITIS OPTICA: A REVIEW AND CASE REPORT

Background

Neuromyelitis optica spectrum disorder (NMOSD) is a relatively new terminology composed to encompass patients with neuromyelitis optica (NMO) and related immunological conditions. The diagnosis of this condition requires a seropositive aquaporin-4 immunoglobulin G (AQP-4 IgG), the presence of at least one core clinical characteristic and the exclusion of alternative diagnoses. Very few cases have been reported in sub-Saharan Africa.

Objective

The aim of this article is to report a classical case of NMOSD with AQP-4 IgG seropositivity and normal brain, cervical and thoracic MRI findings.

Result

We report a 25-year-old Nigerian woman who presented with recurrent and alternating weakness, pain and numbness of all limbs, associated with episodic painful left-sided tonic spasms and urinary incontinence. She had earlier had symptoms of recurrent, episodic and alternating loss of vision in both eyes, associated with ocular pain.Examination findings revealed an intact mental status, no cranial nerve deficit and no focal limb weakness. Right-sided deep tendon reflexes were exaggerated. Vital signs were within normal limits. Brain MRI, Cervical spine MRI and Thoracic spine MRI all revealed normal findings. Serum aquaporin-4 IgG assay returned positive with a titer of 1:32.She was commenced on high dose steroids and there was gradual improvement of symptoms.

Conclusion

These findings confirmed the diagnosis of neuromyelitis optica spectrum disorder, and satisfies the diagnostic criteria published in 2015 by the International Panel for NMO Diagnosis (IPND).

A comprehensive review of the advances in neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a rare relapsing neuroinflammatory autoimmune astrocytopathy, with a predilection for the optic nerves and spinal cord. Most cases are characterised by aquaporin-4-antibody positivity and have a relapsing disease course, which is associated with accrual of disability. Although the prognosis in NMOSD has improved markedly over the past few years owing to advances in diagnosis and therapeutics, it remains a severe disease. In this article, we review the evolution of our understanding of NMOSD, its pathogenesis, clinical features, disease course, treatment options and associated symptoms. We also address the gaps in knowledge and areas for future research focus.

Tocilizumab treatment in neuromyelitis optica spectrum disorders: Updated meta-analysis of efficacy and safety

This systematic review and meta-analysis summarize the efficacy and safety of Tocilizumab (TCZ) in treating NMOSD and investigates the factors that affect its efficacy. TCZ is the first monoclonal antibody against the IL-6 receptor for treating NMOSD, and its efficacy and safety vary in different studies. We collected English-language research literature until January 1, 2023, by searching databases such as PubMed, MEDLINE, Embase, Cochrane Library, and clinicaltrials.gov, and identified 9 studies involving 153 patients (139 female and 14 male) that met our inclusion criteria. In these studies, the average ARR ratio and EDSS score reduction values in the TCZ treatment group were -1.34 (95 % CI, -1.60 to -1.09) and -0.81 (95 % CI, -1.04 to -0.58), respectively. Based on the data we have collected, compared to the AQP4-IgG negative NMOSD patients, TCZ demonstrates a more pronounced effectiveness in AQP4-IgG positive NMOSD patients. The study also found that the effectiveness of TCZ in reducing NMOSD patients' ARR ratio was related to gender, race, and TCZ dosage, while the effectiveness of reducing EDSS score was not related to these factors. Among the 153 patients receiving TCZ treatment, 101 (66 %) experienced mild adverse reactions, and one patient experienced a severe adverse reaction (facial cellulitis). The comprehensive data indicate that TCZ treatment can reduce the frequency of NMOSD relapses, improve patients' neurological function, and have good safety. The effectiveness of TCZ in reducing NMOSD patients' ARR ratio is related to multiple factors.

Methyl-CpG-Binding Protein 2 Emerges as a Central Player in Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorders

MECP2 and its product methyl-CpG binding protein 2 (MeCP2) are associated with multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD), which are inflammatory, autoimmune, and demyelinating disorders of the central nervous system (CNS). However, the mechanisms and pathways regulated by MeCP2 in immune activation in favor of MS and NMOSD are not fully understood. We summarize findings that use the binding properties of MeCP2 to identify its targets, particularly the genes recognized by MeCP2 and associated with several neurological disorders. MeCP2 regulates gene expression in neurons, immune cells and during development by modulating various mechanisms and pathways. Dysregulation of the MeCP2 signaling pathway has been associated with several disorders, including neurological and autoimmune diseases. A thorough understanding of the molecular mechanisms underlying MeCP2 function can provide new therapeutic strategies for these conditions. The nervous system is the primary system affected in MeCP2-associated disorders, and other systems may also contribute to MeCP2 action through its target genes. MeCP2 signaling pathways provide promise as potential therapeutic targets in progressive MS and NMOSD. MeCP2 not only increases susceptibility and induces anti-inflammatory responses in immune sites but also leads to a chronic increase in pro-inflammatory cytokines gene expression (IFN-γ, TNF-α, and IL-1β) and downregulates the genes involved in immune regulation (IL-10, FoxP3, and CX3CR1). MeCP2 may modulate similar mechanisms in different pathologies and suggest that treatments for MS and NMOSD disorders may be effective in treating related disorders. MeCP2 regulates gene expression in MS and NMOSD. However, dysregulation of the MeCP2 signaling pathway is implicated in these disorders. MeCP2 plays a role as a therapeutic target for MS and NMOSD and provides pathways and mechanisms that are modulated by MeCP2 in the regulation of gene expression.

Severe disease reactivation in seropositive neuromyelitis optica spectrum disorders patients after stopping eculizumab treatment

INTRODUCTION

Neuromyelitis optica spectrum disorders (NMOSD) is an autoimmune, inflammatory disease of the central nervous system affecting the optic nerves and spinal cord. Most NMOSD patients have autoantibodies against the astrocyte water channel protein aquaporin-4 (AQP4). Eculizumab treatment is used effectively and safely in AQP4-IgG+ NMOSD. Our study evaluated the prognosis and outcomes of all clinical trial (PREVENT) patients from Turkey who received eculizumab treatment for AQP4-IgG+ NMOSD.

METHOD

Clinical and demographic data of all patients enrolled in the PREVENT and OLE clinical trial in Turkey were analyzed during the study period and after the study ended. Clinical follow-up results were recorded in detail in patients who had to discontinue eculizumab treatment.

RESULTS

The study included 10 patients who participated in PREVENT and OLE. Seven patients completed the studies, three patients did not continue the study and were switched to other treatments. Only one of the seven patients was able to continue treatment after eculizumab was approved in AQP4-IgG+NMOSD. The other six patients could not continue treatment due to reimbursement conditions. Four of the six patients who could not continue eculizumab treatment experienced early relapse (within the first three months after stopping the drug). All of these patients had high disease activity before eculizumab and had never relapsed under eculizumab treatment over the long term.

CONCLUSION

Eculizumab was used effectively and safely in Turkish AQP4-IgG+NMOSD patients with high disease activity. Disease reactivation and relapse may occur after discontinuation of eculizumab treatment in patients with a long-term stable course. In these cases, close monitoring for disease reactivation is recommended.

Double-negative neuromyelitis optica spectrum disorder

Most patients with neuromyelitis optica spectrum disorders (NMOSD) test positive for aquaporin-4 antibody (AQP4-IgG) or myelin oligodendrocyte glycoprotein antibodies (MOG-IgG). Those who are negative are termed double-negative (DN) NMOSD and may constitute a diagnostic and therapeutic challenge. DN NMOSD is a syndrome rather than a single disease, ranging from a (postinfectious) monophasic illness to a more chronic syndrome that can be indistinguishable from AQP4-IgG+ NMOSD or develop into other mimics such as multiple sclerosis. Thus, underlying disease mechanisms are likely to be heterogeneous. This topical review aims to (1) reappraise antibody-negative NMOSD definition as it has changed over time with the development of the AQP4 and MOG-IgG assays; (2) outline clinical characteristics and the pathophysiological nature of this rare entity by contrasting its differences and similarities with antibody-positive NMOSD; (3) summarize laboratory characteristics and magnetic resonance imaging findings of DN NMOSD; and (4) discuss the current treatment for DN NMOSD.

Neuromyelitis Optica Spectrum Disorder Management in the Setting of Chronic Hepatitis B and Latent Tuberculosis: A Case Report

Neuromyelitis Optica Spectrum Disorder (NMOSD) is an inflammatory autoimmune disorder of the central nervous system, with optic neuritis and transverse myelitis as its most common presentations. Although immunomodulatory treatment options for NMOSD have expanded, preventing reactivation of latent infections in patients can be both a therapeutic challenge and a special consideration for the neurohospitalist in an inpatient setting. We present a challenging case of a NMOSD patient who presented to the emergency department with worsening weakness and numbness in the setting of an NMOSD pseudo-relapse, later found to have untreated latent tuberculosis (TB) and chronic hepatitis B (HBV). She was briefly treated with high-dose IV methylprednisolone, which was stopped after her symptoms and imaging became more consistent with a pseudo-relapse. After confirmation that neither HBV nor TB had reactivated, the patient was discharged on isoniazid and entecavir. A month later, the patient's symptoms were stable, and she was started on inebilizumab for relapse prevention of NMOSD. This case report is the first to highlight the therapeutic complexities of managing NMOSD that requires immunosuppression in the setting of preventing reactivation of both TB and HBV.

Interleukin 6: at the interface of human health and disease

Interleukin 6 (IL-6) is a pleiotropic cytokine executing a diverse number of functions, ranging from its effects on acute phase reactant pathways, B and T lymphocytes, blood brain barrier permeability, synovial inflammation, hematopoiesis, and embryonic development. This cytokine empowers the transition between innate and adaptive immune responses and helps recruit macrophages and lymphocytes to the sites of injury or infection. Given that IL-6 is involved both in the immune homeostasis and pathogenesis of several autoimmune diseases, research into therapeutic modulation of IL-6 axis resulted in the approval of a number of effective treatments for several autoimmune disorders like neuromyelitis optica spectrum disorder (NMOSD), rheumatoid arthritis, juvenile idiopathic arthritis, polyarticular juvenile idiopathic arthritis, giant cell arteritis (GCA), and cytokine release syndrome, associated with SARS-CoV2 pneumonia. This review discusses downstream inflammatory pathways of IL-6 expression and therapeutic applications of IL-6 blockade, currently investigated for the treatment of several other autoimmune conditions such as autoimmune encephalitis, autoimmune epilepsy, as well as myelin oligodendrocyte glycoprotein associated demyelination (MOGAD). This review further highlights the need for clinical trials to evaluate IL-6 blockade in disorders such neuropsychiatric lupus erythematosus (SLE), sarcoidosis and Behcet's.

A Clinical Approach to Existing and Emerging Therapeutics in Neuromyelitis Optica Spectrum Disorder

PURPOSE OF REVIEW

Neuromyelitis optica spectrum disorder (NMOSD) is a rare but highly disabling disease of the central nervous system. Unlike multiple sclerosis, disability in NMOSD occurs secondary to relapses that, not uncommonly, lead to blindness, paralysis, and death. Recently, newer, targeted immunotherapies have been trialed and are now in the treatment arsenal. We have endeavoured to evaluate the current state of NMOSD therapeutics.

RECENT FINDINGS

This review provides a pragmatic evaluation of recent clinical trials and post-marketing data for rituximab, inebilizumab, satralizumab, eculizumab, and ravalizumab, contrasted to older agents. We also review contemporary issues such as treatment in the context of SARS-CoV2 infection and pregnancy. There has been a dramatic shift in NMOSD morbidity and mortality with earlier and improved disease recognition, diagnostic accuracy, and the advent of more effective, targeted therapies. Choosing a maintenance therapy remains nuanced depending on patient factors and accessibility. With over 100 putative agents in trials, disease-free survival is now a realistic goal for NMOSD patients.

A multicentre, prospective, double-blind study comparing the accuracy of autoantibody diagnostic assays in myasthenia gravis: the SCREAM study

BACKGROUND

Laboratory determination of autoantibodies against acetylcholine receptor (AChR), muscle-specific kinase (MuSK) and other autoantigens have been integrated into the diagnosis of myasthenia gravis (MG). However, evidence supporting the selection of methodologies is lacking.

METHODS

In this prospective, multicentre cohort study, we recruited patients with suspected MG to evaluate the diagnostic accuracy of cell-based assay (CBA), radioimmunoprecipitation assay (RIPA) and enzyme-linked immunosorbent assay (ELISA) in detecting AChR and MuSK autoantibodies. This study is registered with www.clinicaltrials.gov, number NCT05219097.

FINDINGS

2272 eligible participants were recruited, including 2043 MG, 229 non-MG subjects. AChR antibodies were detected in 1478, 1310, and 1280 out of a total of 2043 MG patients by CBA, RIPA, and ELISA, respectively; sensitivity, 72.3% (95% CI, 70.3-74.3), 64.1% (95% CI, 62.0-66.2), 62.7% (95% CI, 60.5-64.8); specificity, 97.8% (95% CI, 95.0-99.3), 97.8% (95% CI, 95.0-99.3), 94.8% (95% CI, 91.9-97.7). MuSK antibodies were found in 59, 50, and 54 from 2043 MG patients by CBA, RIPA and ELISA, respectively; sensitivity, 2.9% (95% CI, 2.2-3.7), 2.4% (95% CI, 1.8-3.2), 2.6% (95% CI, 2.0-3.4); specificity, 100% (95% CI, 98.4-100), 100% (95% CI, 98.4-100), and 99.1% (95% CI, 96.9-99.9). The area under the curve of AChR antibodies tested by CBA was 0.858, and there were statistical differences with RIPA (0.843; p = 0.03) and ELISA (0.809; p < 0.0001).

INTERPRETATION

CBA has a higher diagnostic accuracy compared to RIPA or ELISA in detecting AChR and MuSK autoantibodies for MG diagnosis.

FUNDING

New Terrain Biotechnology, Inc., Tianjin, China.

Research hotspots and trends on neuromyelitis optica spectrum disorders: insights from bibliometric analysis

Neuromyelitis optica spectrum disorders (NMOSD) are demyelinating diseases of the central nervous system, have drawn the attention of many researchers due to the relapsing courses and cumulative disability. A first bibliometric analysis of NMOSD was conducted to identify the research hotspots and emerging trends. Articles relevant to NMOSD published in the core collection of Web of Science were retrieved and analyzed through visualized analysis using CiteSpace and VOSviewer, focusing on annual publication trends, countries, institutions, authors, journals, and keywords. The analysis showed that over the past 30 years, publications related to NMOSD had shown steady growth with slight fluctuations. The United States played an important part in this field, with the highest outputs and the greatest number of citations. Research hotspots of NMOSD had gradually shifted from the definition, biomarkers, and diagnostic criteria to diagnosis and treatment, particularly immunotherapy. This bibliometric analysis provides researchers with a theoretical basis for studying NMOSD and offers guidance for future research directions.

Inpatient care of neuromyelitis optica spectrum disorder in Germany: Nationwide analysis from 2010 to 2021

Background

Despite tremendous development in the treatment of neuromyelitis optica spectrum disorder (NMOSD), less is known about the characteristics of hospitalized patients and inpatient care utilization.

Objective

To investigate the development of inpatient NMOSD case numbers and implemented immunotherapies in the last decade in Germany.

Methods

We conducted a nationwide retrospective study using an administrative database of all hospitalized NMOSD patients between 2010 and 2021. We evaluated yearly data on case numbers, demographics, treatment regimens, and seasonal variations of apheresis therapy as a surrogate marker of severe relapse incidence.

Results

During the observational period case number of inpatients substantially increased (2010:n = 463, 2021:n = 992). The mean age was 48.1 ± 2.5 years (74% females). The pooled yearly rate of plasmapheresis/immunoadsorption was 14% (95% CI [13-15%]), without seasonal variations. Its application peaked in 2013 (18%, 95% CI [15-21%]) with decreasing trend since. Predominant immunotherapy was rituximab (40%, 95% CI [34-45%]), followed by tocilizumab (4%, 95% CI [3-5%]) since 2013 and eculizumab (4%, 95% CI [3-5%]) since 2020. Inpatient mortality ranged between 0% and 1% per year.

Conclusions

Inpatient case numbers of NMOSD substantially increased during the past decade, probably reflecting improving disease awareness. In parallel with the administration of highly effective therapies rate of apheresis therapies decreased. A stable apheresis rate over the year makes seasonal variations of the steroid-refractive relapses unlikely.

The aquaporin-4 water channel and updates on its potential as a drug target for Alzheimer's disease

INTRODUCTION

Although there are several FDA-approved treatments for Alzheimer's disease (AD), only recently have disease-modifying therapies received approval for use in patients. In this narrative review, we examine the history of aquaporin-4 (AQP4) as a therapeutic target for NMOSD (neuromyelitis optica spectrum disorder) and as a potential therapeutic target for AD.

AREAS COVERED

We review the basic science and discovery of AQP4, a transmembrane water-channel essential to regulating water balance in the central nervous system (CNS). We also review the pathogenesis of NMOSD, an autoimmune disease characterized by the destruction of cells that express AQP4. Then, we review how AQP4 is likely involved in the pathogenesis of Alzheimer's disease (AD). Finally, we discuss future challenges with drug design that would modulate AQP4 to potentially slow AD development. The literature search for this article consisted of searching Google Scholar and PubMed for permutations of the keywords 'Alzheimer's disease,' 'aquaporin-4,' 'neuromyelitis optica,' and their abbreviations.

EXPERT OPINION

We place research into AQP4 into context with other recent developments in AD research. A major difficulty with drug development for Alzheimer's is the lack of strategies to cleanly target the early pathogenesis of the disease. Targeting AQP4 may provide such a strategy.

Pediatric Neuromyelitis Optica Spectrum Disorder

Neuromyelitis Optica Spectrum Disorder (NMOSD) is a demyelinating disease with a high relapse rate and risk of disability accrual. The condition is an astrocytopathy, with antibodies to the aquaporin-4 (AQP4) water channel being detected in AQP4-IgG seropositive disease. Presentation is uncommon in the pediatric age range, accounting for about 3%-5% of cases. NMOSD is more prevalent in populations of Black or East Asian ancestry. Core clinical syndromes include optic neuritis, acute myelitis, area postrema syndrome, acute brainstem syndrome, acute diencephalic syndrome, and symptomatic cerebral syndrome. First-line treatment options in pediatrics include rituximab, azathioprine, and mycophenolate mofetil. Over half of children with AQP4-IgG seropositive NMOSD develop permanent disability, particularly in visual and motor domains. Novel therapeutic targets in the adult population have been developed and are changing the treatment landscape for this disorder.

Emerging trends and research foci of neuromyelitis optica spectrum disorder: a 20-year bibliometric analysis

Background

Neuromyelitis optica spectrum disorder (NMOSD) is a demyelinating syndrome of the central nervous system. A tremendous amount of literature on NMOSD has been published. This study aimed to perform a bibliometric analysis of the publications on NMOSD and show its hotspots and development trends.

Methods

We used the Web of Science Core Collection as a database and searched the literature published between 2002 and 2022. CiteSpace, VOSviewer, online bibliometric platform, and R-bibliometrix were used to conduct bibliometric analysis and network visualization, including the number of publications, citations, countries/regions, institutions, journals, authors, references, and keywords.

Results

A total of 3,057 publications on NMOSD were published in 198 journals by 200 authors at 200 institutions from 93 countries/regions. The United States published the most literature and made great contributions to this field. The Mayo Clinic was the institution with the largest number of publications. The journal with the most publications was Multiple Sclerosis and Related Disorders, and the most co-cited journal was Neurology. The author with the most publications was Fujihara, K., while the most frequently co-cited author was Wingerchuk, DM. The current research hotspots may be focused on "efficacy," "multicenter," "interleukin-6 receptor blockade," "safety," "azathioprine," "tolerance," and "adult".

Conclusion

This study was the first bibliometric analysis of publications on the NMOSD field, visualizing its bibliometric characteristics and gaining insight into the direction, hotspots, and development of global NMOSD research, which may provide helpful information for researchers. Future research hotspots might be conducting randomized controlled trials on targeted immunotherapy in the NMOSD field.

New advancements in the management of Neuromyelitis Optica spectrum disease: literature review

Neuromyelitis Optica spectrum disorder (NMOSD) is a relapsing autoimmune disease of the central nervous system (CNS) where aquaporin-4 water channels are the antigenic target of the disease. The spectrum of the disease involves regions of the CNS where the water channel is widely expressed including the spinal cord, the optic nerve, dorsal medulla, brainstem, and thalamus/hypothalamus. Management of NMOSD includes acute as well as long term treatment. Acute symptoms are typically treated with intravenous corticosteroids and/or plasma exchange while long-term treatment involves the use of immunosuppression/immune modulation. The year 2019 is thought to be the "year of the NMOSD" as three new medications became available for this devastating disease. In this review, FDA approved NMOSD medications are discussed.

Systematic Review of Treatment Options and Therapeutic Responses for Lesions of the Sella and Orbit: Evidence-Based Recommendations

OBJECTIVE

Inflammatory pathologies of the sella and orbit are rare but require prompt diagnosis to initiate effective treatment. Because uniform recommendations for treatment are currently lacking, we performed an evidence-based review to identify recommendations.

METHODS

We performed a literature search of the PubMed, Embase, and Web of Science databases to identify papers evaluating treatment of inflammatory pathologies of the sella and orbit. We used PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines to define recommendations, specifically examining aggregated sample sizes, disease-specific patient follow-up, and clinical trials focused on inflammatory diseases of the sella and orbit.

RESULTS

A total of 169 studies were included and organized by disease pathology. Treatments for various pathologies were recorded. Treatment options included surgery, radiation, steroids, targeted treatments, immunomodulators, intravenous immune globulin, and plasmapheresis. Steroids were the most often employed treatment, second-line management options and timing varied. Pathological diagnosis was highly associated with treatment used. Most evidence were level 3 without available control groups, except for 13 trials in neuromyelitis optica with level 1 or 2 evidence.

CONCLUSIONS

This is the first evidence-based review to provide recommendations on specific treatments for pathologies of the orbit and sella. The reported data may be useful to help guide randomized clinical trials and provide resource for clinical management decisions based on the available evidence.

High-efficacy therapies reduce clinical and radiological events more effectively than traditional treatments in neuromyelitis optica spectrum disorder

BACKGROUND

People with neuromyelitis optica spectrum disorder (pwNMOSD) experience debilitating neurological attacks, resulting in permanent disability.

OBJECTIVE

To evaluate if high-efficacy treatment was better than traditional agents at preventing disease advancement in pwNMOSD.

METHODS

A retrospective study of pwNMOSD at one academic center was performed. Timelines were created for treatments subjects were exposed to along with clinical/radiological events related to disease worsening. High-efficacy treatments included eculizumab, inebilizumab, satralizumab, rituximab, ocrelizumab, tocilizumab, and sarilumab while therapies such as azathioprine, methotrexate, cyclophosphamide, and mycophenolate mofetil were classified as traditional agents. Poisson regression and mixed effects logistics models were constructed, and a subject-specific random intercept was used for intrasubject correlation.

RESULTS

Of 189 pwNMOSD identified, 161 were aquaporin-4 IgG positive (AQP4 +) with 92 (77 female; median disease duration (MDD) (range) of 6.6 years (y) (1.2-18.6)) exposed only to high-efficacy therapy, 33 (28 female; 10.4 y (0.8-32.7)) only to traditional therapy, and 64 (54 female; 10.8 y (0.7-20.2)) to both. High-efficacy treatments reduced the rate of MRI advancement by 62.4% (95% CrI = [- 86.9%, - 16.8%]), relapses by 99.8% (95% CrI = [- 99.9%, - 99.6%]), and hospitalizations by 99.3% (95% CrI = [- 99.6%, - 98.8%]) when compared to traditional treatments. For AQP4 + subjects, a 655.7-fold increase in the odds of new spinal cord lesion development (95% CrI = [+ 37.4-fold, + 3239.5-fold]) was observed with traditional agents (p < 0.0001).

CONCLUSION

High-efficacy treatments maximize opportunity for preventing disease advancement in newly diagnosed and established pwNMOSD.

Efficacy and safety of monoclonal antibody therapy in patients with neuromyelitis optica spectrum disorder: A systematic review and network meta-analysis

Introduction

Neuromyelitis optica spectrum disorder (NMOSD) is a devastating inflammatory CNS demyelinating disease. Two groups of monoclonal antibodies (mAbs) are used to prevent disease relapse, i.e., Food and Drug Administration (FDA)-approved mAbs (e.g., eculizumab satralizumab, inebilizumab), and off-label mAb drugs (e.g., rituximab and tocilizumab). The FDA-approved mAbs have high efficacy but more expensive compared to the off-labels, and thus are less accessible. This systematic review and network meta-analysis (NMA) was to assess the efficacy and safety of both classes of mAbs compared to the current standard treatments.

Methods

Systematically searches were conducted in MEDLINE and SCOPUS from inception until July 2021. Randomized-controlled trials (RCTs) were eligible if they compared any pair of treatments (mAbs, immunosuppressive drugs, or placebo) in adult patients with NMOSD. Studies with AQP4-IgG positive or negative were used in the analysis. Probability of relapse and time to event were extracted from the Kaplan-Meier curves using Digitizer. These data were then converted into individual patient time-to-event data. A one-stage mixed-effect survival model was applied to estimate the median time to relapse and relative treatment effects using hazard ratios (HR). Two-stage NMA was used to determine post-treatment annualized relapse rate (ARR), expanded disability status score (EDSS) change, and serious adverse events (SAE). Risk of bias was assessed using the revised cochrane risk of bias tool.

Results

A total of 7 RCTs with 776 patients were eligible in the NMA. Five of the seven studies were rated low risk of bias. Both FDA-approved and off-label mAbs showed significantly lower risk of relapse than standard treatments, with HR (95% CI) of 0.13 (0.07, 0.24) and 0.16 (0.07, 0.37) respectively. In addition, the FDA-approved mAbs had 20% lower risk of relapse than the off-label mAbs, but this did not reach statistical significance. The ARRs were also lower in FDA-approved and off-label mAbs than the standard treatments with the mean-difference of−0.27 (-0.37,−0.16) and−0.31(-0.46,−0.16), respectively.

Conclusion

The off-label mAbs may be used as the first-line treatment for improving clinical outcomes including disease relapse, ARR, and SAEs for NMOSD in countries where resources and accessibility of the FDA-approved mAbs are limited.

Systematic review registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=283424, identifier: CRD42021283424.

Clinical and epidemiological correlates of treatment change in patients with NMOSD: insights from the CIRCLES cohort

OBJECTIVE

Neuromyelitis optica spectrum disorders (NMOSD) represent rare autoimmune diseases of the central nervous system largely targeting optic nerve(s) and spinal cord. The present analysis used real-world data to identify clinical and epidemiological correlates of treatment change in patients with NMOSD.

METHODS

CIRCLES is a longitudinal, observational study of NMOSD conducted at 15 centers across North America. Patients with ≥ 60 days of follow-up and receiving on-study maintenance treatment were evaluated. The mean annual relapse rate (ARR) was estimated using negative binomial models; the likelihood of treatment change was estimated using Cox proportional hazards models. Relapses were included as time-varying covariates to estimate the relationship to treatment change.

RESULTS

Of 542 patients included, 171 (31.5%) experienced ≥ 1 relapse on the study and 133 patients (24.5%) had ≥ 1 change in the treatment regimen. Two categories of variables significantly correlated with the likelihood of treatment change: (1) relapse: any on-study relapse (hazard ratio [HR] = 2.91; p < 0.001), relapse phenotypes (HR range = 2.15-5.49; p < 0.001), and pre-study ARR > 0.75 (HR 2.28; p < 0.001); 2) disease phenotype: brain syndrome only vs transverse myelitis involvement at onset (HR 2.44; p = 0.008), disease duration < 1 vs > 5 years (HR 1.66; p = 0.028), or autoimmune comorbidity (HR 1.55; p = 0.015). A subset of these factors significantly correlated with shorter time to first rituximab discontinuation.

CONCLUSIONS

In CIRCLES, relapse patterns and disease phenotype significantly correlated with changes in the maintenance treatment regimen. Such findings may facilitate the identification of patients with NMOSD who are likely to benefit from treatment change to reduce relapse risk or disease burden and enhance the quality of life.

Tocilizumab-treated convalescent COVID-19 patients retain the cross-neutralization potential against SARS-CoV-2 variants

Although tocilizumab treatment in severe and critical coronavirus disease 2019 (COVID-19) patients has proven its efficacy at the clinical level, there is little evidence supporting the effect of short-term use of interleukin-6 receptor blocking therapy on the B cell sub-populations and the cross-neutralization of SARS-CoV-2 variants in convalescent COVID-19 patients. We performed immunological profiling of 69 tocilizumab-treated and non-treated convalescent COVID-19 patients in total. We observed that SARS-CoV-2-specific IgG1 titers depended on disease severity but not on tocilizumab treatment. The plasma of both treated and non-treated patients infected with the ancestral variant exhibit strong neutralizing activity against the ancestral virus and the Alpha, Beta, and Delta variants of SARS-CoV-2, whereas the Gamma and Omicron viruses were less sensitive to seroneutralization. Overall, we observed that, despite the clinical benefits of short-term tocilizumab therapy in modifying the cytokine storm associated with COVID-19 infections, there were no modifications in the robustness of B cell and IgG responses to Spike antigens.

Different monoclonal antibodies and immunosuppressants administration in patients with neuromyelitis optica spectrum disorder: a Bayesian network meta-analysis

BACKGROUND

A variety of novel monoclonal antibodies and immunosuppressant have been proved effective in treating Neuromyelitis Optica Spectrum Disorder (NMOSD). This network meta-analysis compared and ranked the efficacy and tolerability of currently used monoclonal antibodies and immunosuppressive agents in NMOSD.

METHODS

Electronic database including PubMed, Embase and Cochrane Library were searched for relevant studies evaluating monoclonal antibodies and immunosuppressants in patients with NMOSD. The primary outcome measures were annualized relapse rate (ARR), relapse rate, the Expanded Disability Status Scale (EDSS) score, and total adverse events (AEs).

RESULTS

We identified 25 studies with 2919 patients in our meta-analysis. For the primary outcome, rituximab (RTX) (SUCRA: 0.02) ranked first in reduction ARR with a significant difference compared with azathioprine (AZA) (MD - 0.34, 95% CrI - 0.55 to - 0.12) and mycophenolate mofetil (MMF) (MD -0.38, 95% CrI - 0.63 to - 0.14). Tocilizumab (SUCRA: 0.05) ranked first in relapse rate, which was superior to satralizumab (lnOR - 25.4, 95% CrI - 74.4 to - 2.49) and inebilizumab (lnOR - 24.86, 95% CrI - 73.75 to - 1.93). MMF (SUCRA: 0.27) had the fewest AEs followed by RTX (SUCRA: 0.35), both of which showed a significant difference compared with AZA and corticosteroids (MMF vs AZA: lnOR - 1.58, 95% CrI - 2.48 to - 0.68; MMF vs corticosteroids: lnOR - 1.34, 95% CrI - 2.3 to - 0.37) (RTX vs AZA: lnOR - 1.34, 95% CrI - 0.37 to - 2.3; RTX vs corticosteroids: lnOR - 2.52, 95% CrI - 0.32 to - 4.86). In EDSS score, no statistical difference was found between different interventions.

CONCLUSION

RTX and tocilizumab showed better efficacy than traditional immunosuppressants in reducing relapse. For safety, MMF and RTX had fewer AEs. However, studies with larger sample size on newly developed monoclonal antibodies are warranted in the future.

Aquaporin-4 Antibody Dynamics and Relapse Risk in Seropositive Neuromyelitis Optica Spectrum Disorder Treated with Immunosuppressants

OBJECTIVE

To investigate aquaporin-4 antibody (AQP4-IgG) dynamics and relapse risk in patients with seropositive neuromyelitis optica spectrum disorder treated with immunosuppressants.

METHODS

This observational cohort study with prospectively collected data included 400 neuromyelitis optica spectrum disorder patients seropositive for AQP4-IgG and treated with immunosuppressants. Serum AQP4-IgG was detected by fixed cell-based assay every 6 months.

RESULTS

After treatment with immunosuppressants, 128 patients became AQP4-IgG seronegative. The median time to become seronegative for 400 patients was 76.4 months (61.4 months, NA). Among those patients with negative change of AQP4-IgG, the mean annualized relapse rate significantly decreased after patients became seronegative (0.20 vs 0.77, p < 0.001), and a positive correlation was observed between time to become seronegative and relapse (OR 1.018, 95% CI 1.001-1.035, p < 0.05). Independent risk factors for AQP4-IgG becoming seronegative were older age at onset, initiation of immunosuppressants at onset, and shorter disease duration before maintenance therapy. Independent risk factors for relapse included younger age (≤46.4 years) at onset, poly-system involvement in the first attack, and unchanged or increased AQP4-IgG titer. The relapse risk was not associated with sex, combination with connective tissue disease, seropositivity for systemic autoimmune antibodies, or incomplete recovery from the first attack.

INTERPRETATION

Patients with younger age at onset, poly-system involvement in the first attack, and unchanged or increased titer of AQP4-IgG are most likely to experience relapse under treatment with immunosuppressants. Time to AQP4-IgG becoming seronegative and change of AQP4-IgG titer may become the surrogate efficacy biomarkers in clinical trials. ANN NEUROL 2023.

Understanding Treatment Decisions in Neuromyelitis Optica Spectrum Disorder: A Global Clinical Record Review with Patient Interviews

INTRODUCTION

We sought insights into neuromyelitis optica spectrum disorder (NMOSD) treatment practices worldwide.

METHODS

Neurologists from the USA, Germany, Italy, Brazil, South Korea, and China completed an online survey, contributing clinical records for aquaporin-4 (AQP4) immunoglobulin G (IgG)-seropositive adults with NMOSD, which included patient demographics, diagnosis, maintenance treatment history, relapse occurrence, and severity. Interviewed patients receiving NMOSD maintenance therapy provided information about their diagnosis, treatment, perceptions about relapse severity or disease stability, and treatment switches.

RESULTS

A total of 389 neurologists submitted clinical records for 1185 patients with AQP4-IgG-seropositive NMOSD; 33 patients with NMOSD were interviewed. Approximately 25% (228/910) of patients from the clinical record review (CRR) were initially misdiagnosed; 24% (8/33) of patients interviewed reported formal misdiagnosis. Misdiagnosis was associated with treatment delay and more relapses compared with correct diagnosis (mean 3.3 vs 2.8). Maintenance therapy was not initiated within 2 months for 47% (221/472) of patients from the CRR and 24% (8/33) of interviewed patients. Oral corticosteroids/immunosuppressive therapies were typically the first maintenance treatment initiated, except for the USA, where monoclonal antibodies were equally likely to be prescribed. Relapse severity influenced the decision to initiate/change therapy and use monoclonal antibodies. Of interviewed patients, 76% (25/33) did not recall having a choice of treatment and many did not know the rationale for treatment choice.

CONCLUSION

Misdiagnosis of NMOSD appears to be common and is associated with a delay in initiation of maintenance therapy, with decisions influenced by relapse severity. Further real-world studies assessing relapse severity in treatment initiation/switch are required to revise NMOSD treatment recommendations.

Optic neuritis: current challenges in diagnosis and management

PURPOSE OF REVIEW

The primary aim of this review is to describe the clinical course, salient imaging features, and relevant serological profiles of common optic neuritis (ON) subtypes. Key diagnostic challenges and treatment options will also be discussed.

RECENT FINDINGS

ON is a broad term that describes an inflammatory optic nerve injury arising from a variety of potential causes. ON can occur sporadically, however there is particular concern for co-associated central nervous system (CNS) inflammatory syndromes including multiple sclerosis (MS), neuromyelitis optic spectrum disorders (NMOSD), and myelin oligodendrocyte glycoprotein antibody associated disease (MOGAD). The ON subtypes that often herald MS, NMOSD, and MOGAD differ with respect to serological antibody profile and neuroimaging characteristics, yet there is significant overlap in their clinical presentations. A discerning history and thorough examination are critical to rendering the correct diagnosis.

SUMMARY

Optic neuritis subtypes vary with respect to their long-term prognosis and accordingly, require different acute treatment strategies. Moreover, delays in identifying MOGAD, and certainly NMOSD, can be highly detrimental because affected individuals are vulnerable to permanent vision loss and neurologic disability from relapses.

A comparison of the efficacy of tocilizumab versus azathioprine for neuromyelitis optica spectrum disorder: A study protocol for systematic review and meta-analysis

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is a chronic inflammatory disease of the nervous system, which is frequently accompanied by a pathological humoral immune response against aquaporin-4 water channel. The most common feature of the disorder is recurrent episodes of longitudinally extensive transverse myelitis and optic neuritis. Frequent relapse leads to the gradual accumulation of neurological dysfunction. Azathioprine (AZA) is an empirical attack -preventive immunotherapies drug to prevent the relapse of NMOSD, and tocilizumab (TCZ) has been also reported reduce the activity of NMOSD. Therefore, we designed this systematic review and meta-analysis to evaluate the efficacy between TCZ and AZA in the treatment of NMOSD patients.

METHODS

This study followed the PRISMA guidelines. We searched the English literature between 2000 and 2022 by using relevant medical subject heading and entry terms in PubMed, MEDLINE, Embase and CENTRAL databases. A meta-analysis of drug efficacy was performed using expanded disability status scale score and annualized relapse rate (ARR) as the primary outcome indicators.

RESULTS

The literature search found a total of 1546 articles about TCZ and AZA in the treatment of NMOSD, 27 of which were included in this study after a series of screening. 930 and 148 patients with NMOSD were enrolled, who had been treated with AZA and TCZ, respectively. The pooled standardized mean difference (SMD) of expanded disability status scale score before and after AZA treated was -0.40 (95%CI: -0.50, -0.30) (I2 = 65.4%, P < .001), before and after TCZ treated was -0.84 (95%CI: -1.08, -0.60) (I2 = 45.6%, P = .076). The SMD of ARR before and after AZA treated was -1.01 (95%CI: -1.12, -0.90) (I2 = 83.4%, P < .001), before and after TCZ treated was -1.27 (95%CI: -1.52, -1.03) (I2 = 52.7%, P = .039). In addition, TCZ reduce ARR more significantly compared with AZA (P = .031).

CONCLUSION

The results of this study showed that the treatment of NMOSD patients with AZA and TCZ are associated with decreased number of relapses and disability improvement as well. In addition, compared with AZA, TCZ more significantly reduce ARR.

Repurposing MS immunotherapies for CIDP and other autoimmune neuropathies: unfulfilled promise or efficient strategy?

Despite advances in the treatment of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and other common autoimmune neuropathies (AN), still-many patients with these diseases do not respond satisfactorily to the available treatments. Repurposing of disease-modifying therapies (DMTs) from other autoimmune conditions, particularly multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD), is a promising strategy that may accelerate the establishment of novel treatment choices for AN. This approach appears attractive due to homologies in the pathogenesis of these diseases and the extensive post-marketing experience that has been gathered from treating MS and NMOSD patients. The idea is also strengthened by a number of studies that explored the efficacy of DMTs in animal models of AN but also in some CIDP patients. We here review the available preclinical and clinical data of approved MS therapeutics in terms of their applicability to AN, especially CIDP. Promising therapeutic approaches appear to be B cell-directed and complement-targeting strategies, such as anti-CD20/anti-CD19 agents, Bruton's tyrosine kinase inhibitors and anti-C5 agents, as they exert their effects in the periphery. This is a major advantage because, in contrast to MS, their action in the periphery is sufficient to exert significant immunomodulation.

A real-world study of interleukin-6 receptor blockade in patients with neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing autoimmune disease that can cause permanent neurological disabilities. However, the interleukin-6 (IL-6) signaling pathway is a promising therapeutic target for relapse prevention. Therefore, this study evaluated the long-term effectiveness of tocilizumab, a humanized anti-IL-6 receptor antibody, for NMOSD. We enrolled 65 patients with NMOSD who received regular intravenous administration of tocilizumab (8 mg/kg) between October 2017 and January 2022. Then, we retrospectively collected data on the clinical characteristics and baseline glial fibrillary acidic protein (GFAP) and neurofilament light chain levels. The primary outcome was the annualized relapse rate (ARR). Risk factors were assessed using a multivariable logistic regression model. During the median follow-up of 34.1 (interquartile range: 25.5-39.3) months, 23% (15/65) of patients relapsed during tocilizumab treatment, but the median ARR decreased from 1.9 (range 0.12-6.29) to 0.1 (range 0-1.43, p < 0.0001). A prolonged infusion interval (> 4 weeks, odds ratio [OR]: 10.7, 95% confidence interval [CI]: 1.6-71.4, p = 0.014) and a baseline plasma GFAP level of > 220 pg/mL (OR: 20.6, 95% CI 3.3-129.4, p  = 0.001) were risk factors for future relapses. During treatment, the median Expanded Disability Status Scale score significantly decreased in aquaporin-4 antibody-positive and -negative patients, but the pain did not considerably improve. There were no severe safety concerns. Tocilizumab treatment significantly reduced the relapse rate in patients with NMOSD. However, prolonged infusion intervals and high baseline plasma GFAP levels may increase the relapse risk during tocilizumab therapy.