Neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein associated disorder-optic neuritis: a comprehensive review of diagnosis and treatment

Optical coherence tomography angiography measurements in neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein antibody disease: A systematic review and meta-analysis

PURPOSE

Neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody disease (MOGAD) are immune-mediated disorders that can often manifest with optic neuritis (ON) among other symptoms. Optical coherence tomography angiography (OCTA) is an emerging diagnostic method that can quantify retinal capillary blood flow and vessel density (VD), which have been shown to be affected in NMOSD and MOGAD. Hence, we aimed to systematically review the studies addressing retinal microvasculature using OCTA in these diseases.

DESIGN

Systematic review and meta-analysis.

METHODS

PubMed, EMBASE, and Web of Sciences were systematically searched to identify articles addressing OCTA measurements in patients with NMOSD or MOGAD. Following the data extraction, a meta-analysis was performed on the study population and OCTA types amongst at least two homogenous studies.

RESULTS

Twenty-two studies on NMOSD, MOGAD, or both were included. Parafoveal superficial retinal capillary plexus (SRCP) VD and radial peripapillary capillary (RPC) VD were diminished in NMOSD ON+ and NMOSD ON- groups compared to healthy controls (HCs). In addition, both the SRCP VD and RPC VD were significantly reduced in NMOSD ON+ compared to NMOSD ON-. However, meta-analysis for deep retinal capillary plexus (DRCP) did not show a significant difference between NMOSD patients and HCs, or among ON+ and ON- patients. Furthermore, there was no significant difference in foveal avascular zone (FAZ) area size between NMOSD patients and HCs. Regarding MOGAD, the meta-analysis showed decreased parafoveal SRCP VD and RPC VD in MOGAD ON+ patients compared to HCs. Comparing NMOSD ON+ and MOGAD ON+, a meta-analysis was conducted for RPC VD, which showed no significant difference between the two groups.

CONCLUSIONS

This systematic review and meta-analysis confirmed reduced VD in the macular and peripapillary areas in NMOSD and MOGAD eyes, particularly in the parafoveal SRCP and RPC, which is further impacted by prior ON.

MOG Antibody Disease: Nuances in Presentation, Diagnosis, and Management

PURPOSE OF REVIEW

Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) is a distinct neuroinflammatory condition characterized by attacks of optic neuritis, transverse myelitis, and other demyelinating events. Though it can mimic multiple sclerosis and neuromyelitis optica spectrum disorder, distinct clinical and radiologic features which can discriminate these conditions are now recognized. This review highlights recent advances in our understanding of clinical manifestations, diagnosis, and treatment of MOGAD.

RECENT FINDINGS

Studies have identified subtleties of common clinical attacks and identified more rare phenotypes, including cerebral cortical encephalitis, which have broadened our understanding of the clinicoradiologic spectrum of MOGAD and culminated in the recent publication of proposed diagnostic criteria with a familiar construction to those diagnosing other neuroinflammatory conditions. These criteria, in combination with advances in antibody testing, should simultaneously lead to wider recognition and reduced incidence of misdiagnosis. In addition, recent observational studies have raised new questions about when to treat MOGAD chronically, and with which agent. MOGAD pathophysiology informs some of the relatively unique clinical and radiologic features which have come to define this condition, and similarly has implications for diagnosis and management. Further prospective studies and the first clinical trials of therapeutic options will answer several remaining questions about the peculiarities of this condition.

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.

Nausea and Vomiting as Initial Manifestations of Pediatric NMOSD

Intractable nausea and vomiting are commonly attributed to gastrointestinal (GI) conditions but can sometimes be a symptom of an underlying central nervous system disease. One potentially overlooked neurologic cause of intractable nausea and vomiting that is refractory to antiemetics is area postrema syndrome (APS). APS is a condition characterized by lesions of the dorsal caudal medulla and is considered a core clinical feature of neuromyelitis optica spectrum disorder (NMOSD). APS is present in up to 30% of patients ultimately diagnosed with NMOSD and can be the first presenting symptom of NMOSD in 12% of patients, as our case illustrates. Importantly, APS is highly responsive to immunotherapy. We present the case of a 14-year-old female with a history of migraines who presented to the emergency department multiple times for persistent nausea, vomiting, and hiccups. Multiple GI diagnoses were considered until she developed additional neurologic symptoms that prompted further workup and revealed the final diagnosis of NMOSD-APS. We posit that NMOSD-APS should be considered in the differential diagnosis for patients with intractable nausea and vomiting, especially in patients with a negative GI workup result and poor response to antiemetics.

Treatment and Rehabilitation of a Patient with Neuromyelitis Optica Spectrum Disorder-Induced Complete Spinal Cord Injury Following COVID-19 Vaccination: A Case Report

Neuromyelitis optica spectrum disease (NMOSD) is a rare autoimmune disorder of the central nervous system characterized by optic neuritis, myelitis, or brain lesions. Its symptoms overlap with those of multiple sclerosis (MS), making a diagnosis of NMOSD challenging. Here, we report a rare case of NMOSD-induced complete spinal cord injury following COVID-19 vaccination. A 52-year-old female patient developed NMOSD-induced complete spinal cord injury after receiving their third dose of the Pfizer-BioNTech COVID-19 vaccine (BNT162b2). Despite the initial diagnosis of complete spinal cord injury, the patient underwent intensive treatment, including rituximab therapy and rehabilitation. As a result, she made a full recovery and transitioned from the ASIA Impairment Scale(AIS)-A to AIS-E. The remarkable neurological recovery from complete spinal cord injury to functional independence highlights the efficacy of a comprehensive treatment approach. In addition, this case emphasizes the need to recognize NMOSD as a potential adverse outcome of COVID-19 vaccination and emphasizes the importance of early diagnosis, timely intervention, and thorough rehabilitation for optimizing patient results. Further case reports and studies are needed to investigate the association between COVID-19 vaccination and the occurrence of NMOSD.

Visualization and analysis of mapping knowledge domains for optic neuritis: a bibliometric research from 2013 to 2022

PURPOSE

To explore the global research trends, hotspots and frontiers of optic neuritis (ON) over the past decade through qualitative and quantitative analysis of bibliometrics.

METHODS

Publications on ON from 2013 to 2022 were retrieved from Web of Science Core Collection (WoSCC). VOSviewer and CiteSpace were mainly used to facilitate bibliometric analysis and visualization.

RESULTS

A total of 3027 papers were retrieved from peer-reviewed publications and the annual research output increased over time. Neurosciences neurology was the most published area. The USA was the most productive and influential country, and in the focus of international cooperation. University College London was the most productive organization and Charite Medical University of Berlin had the largest number of cooperating partners. Paul F contributed the largest number of publications and Wingerchuk DM ranked first among the co-cited authors. Multiple Sclerosis and Related Disorders was the most prolific journal publishing ON research. The most co-cited references mainly focused on the diagnostic criteria for neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS). The keywords formed the following four clusters: the pathophysiology of MS-ON; the autoantibody markers and diagnostic criteria of NMOSD-ON and myelin oligodendrocyte glycoprotein associated disorder-ON (MOGAD-ON); the epidemiology and clinical characteristics of ON; and the treatment of ON.

CONCLUSION

This bibliometrics analysis showed a systematic view of the evolutionary process, research hotspots, and future directions of ON research. It can provide insights for ON research and valuable information for neuro-ophthalmologic specialists to evaluate research policies and promote international cooperation.

Peripheral Retinal Haemorrhages in a Patient with MOG-Associated Optic Neuritis

A 15-year-old female presented with headaches and bilateral vision loss. Fundoscopic examination revealed bilateral optic nerve oedema as well as peripheral retinal haemorrhages. Magnetic resonance imaging of the brain showed findings consistent with bilateral optic neuritis. The patient was started on high dose intravenous corticosteroids but her vision failed to improve. The presence of retinal haemorrhages raised concern that a vasculitis was underlying her symptoms, prompting an extensive work-up, which was unrevealing. Plasmapheresis was initiated and the patient's vision eventually improved to 20/20 in both eyes. Ultimately, she was found to be positive for myelin oligodendrocyte glycoprotein (MOG) antibodies, consistent with a diagnosis of MOG-associated optic neuritis. The patient's course was typical for MOG-associated optic neuritis but her peripheral retinal haemorrhages were atypical, which created diagnostic uncertainty. It is important to be aware of the possibility of retinal findings in this disease. We also review potential causes for retinal haemorrhages in optic neuritis.

Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease and COVID-19: A Systematic Review

Background

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an uncommon neurological disease affecting the central nervous system (CNS). Numerous neurological disorders, including multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), acute transverse myelitis (ATM), and MOGAD, have been reported following the COVID-19 infection during the current COVID-19 pandemic. On the other hand, it has been suggested that patients with MOGAD may be at greater risk for infection (particularly in the current pandemic).

Objective

In this systematic review, we gathered separately 1) MOGAD cases following COVID-19 infection as well as 2) clinical course of patients with MOGAD infected with COVID-19 based on case reports/series.

Methods

329 articles were collected from 4 databases. These articles were conducted from inception to March 1st, 2022.

Results

Following the screening, exclusion criteria were followed and eventually, 22 studies were included. In 18 studies, a mean ± SD time interval of 18.6 ± 14.9 days was observed between infection with COVID-19 and the onset of MOGAD symptoms. Symptoms were partially or completely recovered in a mean of 67 days of follow-up. Among 4 studies on MOGAD patients, the hospitalization rate was 25%, and 15% of patients were hospitalized in the intensive care unit (ICU).

Conclusion

Our systematic review demonstrated that following COVID-19 infection, there is a rare possibility of contracting MOGAD. Moreover, there is no clear consensus on the susceptibility of MOGAD patients to severe COVID-19. However, obtaining deterministic results requires studies with a larger sample size.

[Diagnostic value of low versus high titers of MOG-IgG and their clinical implications in myelin oligodendrocyte glycoprotein antibody-associated disease: a retrospective singlecenter study]

OBJECTIVE

To summarize the clinical characteristics of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and explore the value of MOG-IgG titers for diagnosis and evaluating disease severity of MOGAD.

METHODS

This retrospective study was conducted among the patients positive for serum MOG-IgG admitted in our hospital from December, 2020 to December, 2022. With 1∶100 as the cutoff value of MOG-IgG titer, the patients were divided into low and high MOG-IgG titer groups for comparison of general demographic data, laboratory test results, imaging features, treatment, and prognosis.

RESULTS

Of the 36 patients included, 28 were diagnosed with MOGAD (77.78%), including 15 with low and 13 with high MOG-IgG titers. Compared with the cases reported previously, the MOGAD patients included herein showed a higher prevalence of sensory abnormalities (52.78%) and a lower prevalence of vision loss (25%). Magnetic resonance imaging showed that the periventricular white matter was the most common lesion site (45.71%). The patients with high MOGIgG titers had significantly lower peripheral blood lymphocyte counts (P=0.025) with an increased neutrophil-to-lymphocyte ratio (P=0.045), higher serum free thyroxine levels (P=0.033) and higher cerebrospinal fluid glucose levels (P=0.007) as compared with those with low MOG-IgG titers.

CONCLUSION

Low titers and high titers of MOG-IgG have similar diagnostic value for MOGAD. The serum titers of MOG-IgG are probably associated with the disease severity and stress levels of the patients with MOGAD.

The neuro-ophthalmological manifestations of NMOSD and MOGAD-a comprehensive review

Optic neuritis (ON) is one of the most frequently seen neuro-ophthalmic causes of vision loss worldwide. Typical ON is often idiopathic or seen in patients with multiple sclerosis, which is well described in the landmark clinical trial, the Optic Neuritis Treatment Trial (ONTT). However, since the completion of the ONTT, there has been the discovery of aquaporin-4 (AQP4) and myelin oligodendrocyte glycoprotein (MOG) antibodies, which are biomarkers for neuromyelitis optica spectrum disorder (NMOSD) and MOG antibody-associated disease (MOGAD), respectively. These disorders are associated with atypical ON that was not well characterised in the ONTT. The severity, rate of recurrence and overall outcome differs in these two entities requiring prompt and accurate diagnosis and management. This review will summarise the characteristic neuro-ophthalmological signs in NMOSD and MOGAD, serological markers and radiographic findings, as well as acute and long-term therapies used for these disorders.

A systematic literature review to examine the considerations around pregnancy in women of child-bearing age with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) or aquaporin 4 neuromyelitis optica spectrum disorder (AQP4+ NMOSD)

BACKGROUND

Aquaporin-4 antibody positive (AQP4+) neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are rare autoimmune diseases with overlapping phenotypes. Understanding their clinical manifestation prior to, during and after pregnancy may influence the management of women of child-bearing age (WOCBA) with these diseases.

METHODS

This systematic review identified relevant MEDLINE-indexed publications dated between 01 January 2011 and 01 November 2021, and congress materials from key conferences between 01 January 2019 and 01 November 2021. These were manually assessed for relevance to AQP4+ NMOSD and/or MOGAD in WOCBA, with selected data extracted and considered.

RESULTS

In total, 107 articles were retrieved and reviewed for relevancy, including 65 clinical studies. Limited evidence was found regarding a conclusive impact of either disease on female fertility, sexual function or menarche, and impact on maternal outcomes requires further investigation in both conditions to establish risk for pre-eclampsia, gestational diabetes and other complications relative to the general population. Collated data for pregnancy outcomes show clear risks in AQP4+ NMOSD to healthy delivery and a rise in annualised relapse rate postpartum that may require adaptation of treatment regimens. Disease activity appears to be attenuated during pregnancy in MOGAD patients with an increased risk of relapse during the postpartum months, but strong conclusions cannot be made due to a paucity of available data.

CONCLUSIONS

This review brings together the literature on AQP4+ NMOSD and MOGAD in WOCBA. The potential impact of pregnancy and the postpartum period on disease activity suggest a proactive management strategy early on may improve maternal and infant outcomes, but more clinical data are needed, particularly for MOGAD.

The Treatment of Acute Optic Neuritis

Despite the high incidence of optic neuritis (ON), and the growing number of therapeutic options for the long-term treatment of diseases associated with ON including multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD) and MOG antibody associated disease (MOGAD), there are still only limited therapeutic options for treating an acute event of optic neuritis. These include steroids, plasma exchange (PLEX) and intravenous immunoglobulin (IVIG). High-dose steroids remain the mainstay of acute treatment. However, evidence is emerging that when optic neuritis is accompanied with certain atypical features that suggest a more unfavorable outcome this mandates special consideration such as early addition of other therapeutic agents or tapering the steroid very slowly. This review will distinguish between typical and atypical neuritis and discuss acute treatment options.

Current Updates on the Diagnosis and Management of Multiple Sclerosis for the General Neurologist

Multiple sclerosis (MS) is an immune-driven disease that affects the central nervous system and is characterized by acute-on-chronic demyelination attacks. It is a major cause of global neurological disability, and its prevalence has increased in the United States. Conceptual understandings of MS have evolved over time, including the identification of B cells as key factors in its pathophysiology. The foundation of MS management involves preventing flares so as to avoid long-term functional decline. Treatments may be categorized into low-, middle-, and high-efficacy medications based on their efficacy in relapse prevention. With 24 FDA-approved treatments for MS, individual therapy is chosen based on distinct mechanisms and potential side effects. This review provides a detailed update on the epidemiology, diagnosis, treatment advances, and major ongoing research investigations in MS.

The prevalence and clinical phenotype of dual seropositive neuromyelitis optica spectrum disorders at a national reference center in South Asia

BACKGROUND

Neuromyelitis Optica Spectrum Disorders (NMOSD) is an autoimmune syndrome that is frequently positive for Aquaporin 4 (AQP4) IgG or Myelin Oligodendrocyte Glycoproteins (MOG) IgG. However, dual positivity to both is rare.

OBJECTIVE

To assess the prevalence of dual-positive NMOSD and outline its clinical phenotype.

DESIGN/METHODS

This is a retrospective cross-sectional study conducted at a tertiary healthcare center in South Asia between August 2018 and November 2021. The serum and/or CSF samples of suspected cases of NMOSD were tested for both AQP4-IgG and MOG-IgG using an Indirect immunofluorescence test on transfected cells.

RESULTS

During the study period, 1935 cases of NMOSD were tested for both antibodies- 65 patients (3.35%; 57 females and 8 males) tested positive for AQP4-IgG, 217 patients (11.21%; 122 females and 95 males) tested positive for MOG-IgG and 3 patients (0.15%; 2 females and 1 male) showed dual positivity. There was a strong female preponderance in all three groups (87.69%, 56.22%, and 66.66% respectively). This study identified 3 patients with dual positivity. The first patient (42 years, Male) presented with area postrema syndrome initially and subsequently relapsed by developing right-sided numbness of the temporal area and limbs during which he tested dual positive. The second patient (27 years, Female) presented with bilateral optic neuritis (left>right) initially and subsequently relapsed following an episode of a seizure with left-sided hemiplegia. The third patient (25 years, Female) initially presented with acute bilateral optic neuritis and later developed left-sided hemiplegia post-recovery at which point she tested dual positive. Management using methylprednisolone was ineffective for all three patients, however, plasmapheresis and/or periodic rituximab injections produced an excellent response.

CONCLUSIONS

Our study reports that the prevalence of dual-positive NMOSD is 0.15% and its clinical phenotype is more similar to NMO rather than MOG- associated disease.

Paediatric MOG-antibody disease presenting with intracranial hypertension and unilateral vision loss without radiological evidence of optic neuritis

Intracranial hypertension (IH) is poorly described in paediatric myelin oligodendrocyte glycoprotein antibody disease (MOGAD). We describe a unique case of seropositive MOGAD in an obese 13-year-old boy who presented with an isolated IH, bilateral optic disc swelling and sudden-onset complete vision loss in one eye without radiological evidence of optic nerve involvement. Treatment with intravenous methylprednisolone combined with an emergency shunt fully restored vision and resolved the optic disc swelling. This report adds to the growing body of evidence suggesting that obese children presenting with isolated IH should be investigated for MOGAD, and the importance of managing IH during MOGAD.

MOG Antibody-Associated Disease and Thymic Hyperplasia: From the National Multiple Sclerosis Society Case Conference Proceedings

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a recently described CNS inflammatory disorder that may manifest with optic neuritis, myelitis, seizures, and/or acute disseminated encephalomyelitis. While MOG-specific antibodies in patients with MOGAD are IgG1, a T-cell-dependent antibody isotype, immunologic mechanisms of this disease are not fully understood. Thymic hyperplasia can be associated with certain autoimmune diseases. In this report we describe a case of MOGAD associated with thymic hyperplasia in a young adult.

[Typical and atypical optic neuritis]

Optic neuritis (ON) is one of the most common neuro-ophthalmic causes of vision loss worldwide. Demyelinating ON can be idiopathic or be one of the symptoms of autoimmune demyelinating diseases of the central nervous system (CNS) such as multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). Demographic, clinical and radiological signs of ON in these CNS diseases have differences. In this regard, typical and atypical ON are currently distinguished. Recognizing the clinical features that differentiate typical MS-associated ON from atypical ON in NMOSD and MOGAD is important for choosing the correct disease management and treatment strategy. This review summarizes the data from clinical, laboratory, instrumental methods of management used for the differential diagnosis of optic neuritis.

[Clinical phenotypes of optic nerve damage in patients with neuromyelitis optica spectrum disorder]

Neuromyelitis optica spectrum disorders (NMOSD) comprise a group of autoimmune inflammatory demyelinating diseases of the central nervous system that manifest as optic neuritis and transverse myelitis. Its manifestation in the form of optic neuritis makes early diagnosis difficult because neuroimaging of the spinal cord is not a part of the routine examination algorithm for such patients. This article presents the results of a comprehensive ophthalmological examination of 4 patients (8 eyes) diagnosed with NMSOD. Optic neuritis was the disease debut in 3 patients and had 1-2 relapses, in all cases partial optic atrophy with moderate to severe loss of visual function occurred. The clinical picture was characterized by a pronounced heterogeneity in terms of both ophthalmological symptoms, and accession of neurological disorders. Treatment of NMOSD requires differential diagnosis with multiple sclerosis, which depends on the awareness of specialists and the inclusion of antibody titers to aquaporin-4 and myelin oligodendrocyte glycoprotein into the examination algorithm of patients with optical neuritis.

Update on glial antibody-mediated optic neuritis

Optic neuritis (ON) refers to inflammatory demyelinating lesions of the optic nerve, which can cause acute or subacute vision loss and is a major cause of vision loss in young adults. Much of our understanding of typical ON is from the Optic Neuritis Treatment Trial. Glial autoantibodies to aquaporin-4 immunoglobulin (AQP4-IgG) and myelin oligodendrocyte glycoprotein immunoglobulin (MOG-IgG) are recently established biomarkers of ON that have revolutionized our understanding of atypical ON. The detection of glial antibodies is helpful in the diagnosis, treatment, and follow-up of patients with different types of ON. AQP4-IgG and MOG-IgG screening is strongly recommended for patients with atypical ON. Research on the pathogenesis of NMOSD and MOGAD will promote the development and marketing of targeted immunotherapies. The application of new and efficient drugs, such as the selective complement C5 inhibitor, IL-6 receptor inhibitor, B cell-depleting agents, and drugs against other monoclonal antibodies, provides additional medical evidence. This review provides information on the diagnosis and management of glial antibody-mediated ON.

Progress in treatment of neuromyelitis optica spectrum disorders (NMOSD): Novel insights into therapeutic possibilities in NMOSD

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune inflammatory demyelinating disorder of the central nervous system (CNS), which is a severely disabling disorder leading to devastating sequelae or even death. Repeated acute attacks and the presence of aquaporin-4 immunoglobulin G (AQP4-IgG) antibody are the typical characteristics of NMOSD. Recently, the phase III trials of the newly developed biologicals therapies have shown their effectiveness and good tolerance to a certain extent when compared with the traditional therapy with the first- and second-line drugs. However, there is still a lack of large sample, double-blind, randomized, clinical studies to confirm their efficacy, safety, and tolerability. Especially, these drugs have no clear effect on NMOSD patients without AQP4-IgG and refractory patients. Therefore, it is of strong demand to further conduct large sample, double-blind, randomized, clinical trials, and novel therapeutic possibilities in NMOSD are discussed briefly here.

Optic neuritis with potential for poor outcome

The Optic Neuritis Treatment Trial previously reported that corticosteroids accelerated visual recovery in optic neuritis (ON) without improving outcome. This finding related largely to multiple sclerosis (MS), and subsequently neurologists tended to await spontaneous recovery in ON. Since then, non-MS cases of ON have been identified with antibodies to aquaporin-4 (AQP4) or myelin oligodendrocyte glycoprotein (MOG). These disorders can closely mimic multiple sclerosis-associated or idiopathic demyelinating optic neuritis (MS/IDON) initially but risk a worse visual outcome. Scrutinising the clinical features and neuroimaging often enables differentiation between MS/IDON and other causes of ON. Early treatment with high-dose corticosteroids is an important determinant of visual outcome in non-MS/IDON. Prompt use of plasma exchange may also save sight. In this review, we contrast the presentations of myelin oligodendrocyte glycoprotein associated optic neuritis (MOG-ON) and aquaporin 4 associated optic neuritis (AQP4-ON) with MS/IDON and provide an approach to acute management while awaiting results of antibody testing.

ABCB1 gene polymorphisms impact the effect of high-dose intravenous methylprednisolone therapy on optic neuritis associated with AQP4-IgG-positive neuromyelitis optica spectrum disorder

WHAT IS KNOWN AND OBJECTIVE

Patients with optic neuritis (ON) have significant individual differences in their response to high-dose intravenous methylprednisolone (HIMP) therapy. This study aims to evaluate the association between gene polymorphisms and the efficacy of HIMP therapy in Chinese Han patients with ON mediated by aquaporin-4 immunoglobulin G antibody (AQP4-IgG) -positive neuromyelitis optica spectrum disorder (NMOSD) or multiple sclerosis (MS).

METHODS

Chinese Han patients with AQP4-IgG⁺ NMOSD-ON or MS-ON were genotyped for four candidate genes: ABCB1 (rs1045642, rs1128503, rs2032582), NR3C1 (rs41423247), TBX21 (rs9910408, rs16947078) and VDR (rs731236, rs1544410, rs7975232, rs2228570). Patients were divided into glucocorticoid resistance (GR) and glucocorticoid sensitivity (GS) groups based on vision acuity (VA) improvement after HIMP treatment. Intergroup comparisons were performed on clinical characteristics, allele and genotype frequencies and haplotype distributions.

RESULTS

A total of 267 patients completed the follow-up, including 120 patients with AQP4-IgG⁺ NMOSD-ON and 147 patients with MS-ON. We observed a significant association between the ABCB1 G2677T/A (rs2032582) polymorphism and glucocorticoid response in AQP4-IgG⁺ NMOSD-ON patients. Changes in VA scores in patients with the GG genotype were significantly lower than those in patients with the T/A T/A genotype (1.07 ± 1.20 vs. 1.77 ± 1.31, p = 0.026). In the GS group, the G allele had a lower frequency than the T/A allele (32.03% vs. 60.16%, p = 0.001). Logistic regression analysis showed that the G2677T/A GG and G T/A genotypes could increase the GR risk 3.53 and 2.67 times compared with the T/A T/A genotype, respectively (OR = 3.534, 95% CI: 1.186-10.527, p = 0.023; OR = 2.675, 95% CI: 1.005-7.123, p = 0.049). In addition, haplotype analysis showed that AQP4-IgG⁺ NMOSD-ON patients with the TAT/TTT haplotype (ABCB1 C3435T-G2677T/A-C1236T) were only 0.54 times more likely to develop GR than those with other haplotypes (OR = 0.542, 95% CI: 0.315-0.932, p = 0.026). However, we did not observe intergroup differences in the MS-ON population.

WHAT IS NEW AND CONCLUSION

Our findings suggest that the G > T/A polymorphism of ABCB1 G2677T/A and the TAT/TTT haplotype played a protective role in HIMP treatment of AQP4-IgG⁺ NMOSD-ON but not MS-ON.

Clinical Features and Imaging Findings of Myelin Oligodendrocyte Glycoprotein-IgG-Associated Disorder (MOGAD)

Myelin oligodendrocyte glycoprotein-IgG-associated disorder (MOGAD) is a nervous system (NS) demyelination disease and a newly recognized distinct disease complicated with various diseases or symptoms; however, MOGAD was once considered a subset of neuromyelitis optica spectrum disorder (NMOSD). The detection of MOG-IgG has been greatly improved by the cell-based assay test method. In one study, 31% of NMOSD patients with negative aquaporin-4 (AQP-4) antibody were MOG-IgG positive. MOGAD occurs in approximately the fourth decade of a person’s life without a markedly female predominance. Usually, optic neuritis (ON), myelitis or acute disseminated encephalomyelitis (ADEM) encephalitis are the typical symptoms of MOGAD. MOG-IgG have been found in patients with peripheral neuropathy, teratoma, COVID-19 pneumonia, etc. Some studies have revealed the presence of brainstem lesions, encephalopathy or cortical encephalitis. Attention should be given to screening patients with atypical symptoms. Compared to NMOSD, MOGAD generally responds well to immunotherapy and has a good functional prognosis. Approximately 44-83% of patients undergo relapsing episodes within 8 months, which mostly involve the optic nerve, and persistently observed MOG-IgG and severe clinical performance may indicate a polyphasic course of illness. Currently, there is a lack of clinical randomized controlled trials on the treatment and prognosis of MOGAD. The purpose of this review is to discuss the clinical manifestations, imaging features, outcomes and prognosis of MOGAD.

Optic Neuritis in the Era of NMOSD and MOGAD: A Survey of Practice Patterns in Singapore

PURPOSE

The Optic Neuritis Treatment Trial was a landmark study with implications worldwide. In the advent of antibody testing for neuromyelitis optica spectrum disease (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), emerging concepts, such as routine antibody testing and management, remain controversial, resulting mostly from studies in White populations. We evaluate the practice patterns of optic neuritis investigation and management by neuro-ophthalmologists and neurologists in Singapore.

DESIGN

21-question online survey consisting of 4 clinical vignettes.

METHODS

The survey was sent to all Singapore Medical Council- registered ophthalmologists and neurologists who regularly manage patients with optic neuritis.

RESULTS

Forty-two recipients (17 formally trained neuro-ophthalmol-ogists [100% response rate] and 25 neurologists) responded. Participants opted for routine testing of anti-aquaporin-4 antibodies (88.1% in mild optic neuritis and 97.6% in severe optic neuritis). Anti-MOG antibodies were frequently obtained (76.2% in mild and 88.1% in severe optic neuritis). Plasmapheresis was rapidly initiated (85.7%) in cases of nonresponse to intravenous steroids, even before obtaining anti-aquaporin-4 or anti-MOG serology results. In both NMOSD and MOGAD, oral mycophenolate mofetil was the preferred option if chronic immunosuppression was necessary. Steroids were given for a longer duration and tapered more gradually than in idiopathic optic neuritis cases.

CONCLUSIONS

Serological testing for NMOSD and MOGAD is considered as a routine procedure in cases of optic neuritis in Singapore, possibly due to local epidemiological features of these conditions. Chronic oral immunosuppression is preferred for the long term, but further research is necessary to establish the efficacy and cost-effectiveness of these practices.

Risk Factors and Nomogram for Predicting Relapse Risk in Pediatric Neuromyelitis Optica Spectrum Disorders

Background

Neuromyelitis optica spectrum disorders (NMOSDs) are attack-relapsing autoimmune inflammatory diseases of the central nervous system, which are characterized by the presence of serological aquaporin-4 (AQP4) antibody. However, this disorder is uncommon in children, and AQP4 antibody was often found to be seronegative. However, some pediatric patients diagnosed with NMOSDs were tested to be positive for myelin oligodendrocyte glycoprotein (MOG) antibody. The previous investigations of pediatric NMOSDs were usually focused on the clinical presentation, treatment responses, and long-term prognoses, but little is known about the risk factors predicting NMOSD relapse attacks in a shorter time, especially, for Chinese children.

Methods

We retrospectively identified 64 Chinese pediatric patients, including 39 positive for AQP4 antibody, 12 positive for MOG antibody, and the rest negative for AQP4 and MOG antibodies. Independent risk factors predicting relapse in 1-year follow-up were extracted by multivariate regression analysis to establish a risk score model, its performance evaluation was analyzed using receiver operating characteristic (ROC) curve, and the independent risk factors related to relapse manifestation were also explored through multivariate logistic analysis. A nomogram was generated to assess relapse attacks in 1-year follow-up. Thirty-five patients from 3 other centers formed an external cohort to validate this nomogram.

Results

Four independent relapsed factors included discharge Expanded Disability Status Scale (EDSS) (p = 0.017), mixed-lesion onset (p = 0.010), counts (≧1) of concomitant autoantibodies (p = 0.015), and maintenance therapy (tapering steroid with mycophenolate mofetil (MMF), p = 0.009; tapering steroid with acetazolamide (AZA), p = 0.045; and tapering steroid only, p = 0.025). The risk score modeled with these four factors was correlated with the likelihood of relapse in the primary cohort (AUC of 0.912) and the validation cohort (AUC of 0.846). Also, our nomogram exhibited accurate relapse estimate in the primary cohort, the validation cohort, and the whole cohort, but also in the cohorts with positive/negative AQP4 antibody, and noticeably, it performed predictive risk improvement better than other factors in the concordance index (C-index), net reclassification improvement (NRI), and integrated discrimination improvement (IDI).

Conclusions

The risk score and nomogram could facilitate accurate prognosis of relapse risk in 1-year follow-up for pediatric NMOSDs and help clinicians provide personalized treatment to decrease the chance of relapse.

Emerging concepts in the treatment of optic neuritis: mesenchymal stem cell-derived extracellular vesicles

BACKGROUND

Optic neuritis (ON) is frequently encountered in multiple sclerosis, neuromyelitis optica spectrum disorder, anti-myelin oligodendrocyte glycoprotein associated disease, and other systemic autoimmune disorders. The hallmarks are an abnormal optic nerve and inflammatory demyelination; episodes of optic neuritis tend to be recurrent, and particularly for neuromyelitis optica spectrum disorder, may result in permanent vision loss.

MAIN BODY

Mesenchymal stem cell (MSC) therapy is a promising approach that results in remyelination, neuroprotection of axons, and has demonstrated success in clinical studies in other neuro-degenerative diseases and in animal models of ON. However, cell transplantation has significant disadvantages and complications. Cell-free approaches utilizing extracellular vesicles (EVs) produced by MSCs exhibit anti-inflammatory and neuroprotective effects in multiple animal models of neuro-degenerative diseases and in rodent models of multiple sclerosis (MS). EVs have potential to be an effective cell-free therapy in optic neuritis because of their anti-inflammatory and remyelination stimulating properties, ability to cross the blood brain barrier, and ability to be safely administered without immunosuppression.

CONCLUSION

We review the potential application of MSC EVs as an emerging treatment strategy for optic neuritis by reviewing studies in multiple sclerosis and related disorders, and in neurodegeneration, and discuss the challenges and potential rewards of clinical translation of EVs including cell targeting, carrying of therapeutic microRNAs, and prolonging delivery for treatment of optic neuritis.

Positive antithyroid antibody predicts severity of neuromyelitis optica spectrum disorder in children

BACKGROUND

Neuromyelitis optica spectrum disease (NMOSD) is a rare autoimmune disease, which can coexist with autoimmune thyroid diseases (AITDS). There has been no report on the clinical characteristics of NMOSD in children with positive anti-thyroid antibodies (ATAbs). The aim of this study is to evaluate thyroid function and detect the difference between ATAbs seropositive and seronegative NMOSD children.

METHODS

108 children with a confirmed diagnosis of NMOSD who were admitted to Shengjing Hospital of China Medical University from January 2015 to September 2020 were enrolled and their thyroid functions were evaluated. They were divided into two groups by ATAbs abnormalities. Their demographic characteristics, clinical symptoms, laboratory and MRI scan results of the brain and spinal cord were assessed.

RESULTS

ATAbs positive rate was higher in children with NMOSD when compared with healthy controls (P < 0.05). Most NMOSD children with positive ATAbs were female (P < 0.01). The expanded disability status scale (EDSS) score was significantly higher in the ATAbs positive group (P < 0.01). There were statistically significant differences for the incidence of bulbar area postrema symptoms, spinal cord symptoms, and fever of unknown origin of the first onset between the ATAbs positive and negative group (P < 0.05). The ANA and MOG antibody positive rate, longitudinally extensive transverse myelitis (LETM), and electroencephalogram (EEG) were significantly higher in ATAbs positive group (P < 0.05).

CONCLUSION

MOG antibody-positive is a unique marker of aggravation of neurological dysfunction in ATAbs-positive NMOSD children. Monitoring ATAbs may play an important role in predicting the prognosis of NMOSD.

Bortezomib: a proteasome inhibitor for the treatment of autoimmune diseases

Autoimmune diseases (ADs) are conditions in which the immune system cannot distinguish self from non-self and, as a result, tissue injury occurs primarily due to the action of various inflammatory mediators. Different immunosuppressive agents are used for the treatment of patients with ADs, but some clinical cases develop resistance to currently available therapies. The proteasome inhibitor bortezomib (BTZ) is an approved agent for first-line therapy of people with multiple myeloma. BTZ has been shown to improve the symptoms of different ADs in animal models and ameliorated symptoms in patients with systemic lupus erythematous, rheumatoid arthritis, myasthenia gravis, neuromyelitis optica spectrum disorder, Chronic inflammatory demyelinating polyneuropathy, and autoimmune hematologic diseases that were nonresponsive to conventional therapies. Proteasome inhibition provides a potent strategy for treating ADs. BTZ represents a proteasome inhibitor that can potentially be used to treat AD patients resistant to conventional therapies.

At this Junction…

An 81-year-old woman developed painful vision loss to hand motions in the right eye over a several-day period. Dilated fundus examination revealed no acute pathology, but automated perimetry showed a superotemporal visual field defect in the asymptomatic left eye, suggestive of a junctional scotoma. Magnetic resonance imaging demonstrated enhancement of the right optic nerve extending to its junction with the optic chiasm. The patient's vision failed to improve with intravenous corticosteroids, but demonstrated significant improvement with therapeutic plasma exchange. She was subsequently found to be seropositive for aquaporin-4 autoantibodies, confirming the diagnosis of neuromyelitis optic spectrum disorder.

The role and mechanisms of Microglia in Neuromyelitis Optica Spectrum Disorders

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune neurological disease that can cause blindness and disability. As the major mediators in the central nervous system, microglia plays key roles in immunological regulation in neuroinflammatory diseases, including NMOSD. Microglia can be activated by interleukin (IL)-6 and type I interferons (IFN-Is) during NMOSD, leading to signal transducer and activator of transcription (STAT) activation. Moreover, complement C3a secreted from activated astrocytes may induce the secretion of complement C1q, inflammatory cytokines and progranulin (PGRN) by microglia, facilitating injury to microglia, neurons, astrocytes and oligodendrocytes in an autocrine or paracrine manner. These processes involving activated microglia ultimately promote the pathological course of NMOSD. In this review, recent research progress on the roles of microglia in NMOSD pathogenesis is summarized, and the mechanisms of microglial activation and microglial-mediated inflammation, and the potential research prospects associated with microglial activation are also discussed.