Neuromyelitis optica spectrum disorders: Comparison according to the phenotype and serostatus

Recommendations on NMOSD treatment in Latin America: Utilizing consensus-based RAND/UCLA methodology

INTRODUCTION

Neuromyelitis optica spectrum disorder (NMOSD) is a serious condition affecting people worldwide, including Latin America (LATAM). Healthcare disparities and economic limitations make effective treatment access challenging. It is crucial to consider the best practice therapeutic decision-making, including emerging long-term preventive therapies, to ensure patients in LATAM and elsewhere can effectively manage their disease all over the world.

OBJECTIVES/AIMS

To establish evidence-based guidelines for treatment approaches in NMOSD patients in LATAM. A consensus process was conducted to develop validated statements.

METHODS

A group of NMOSD experts from LATAM utilized a 9-point Likert scale to vote on statements related to NMOSD management. The predetermined consensus threshold was set at a minimum expert agreement of 70 %. The RAND/UCLA methodology was employed to reach consensus recommendations.

RESULTS

Nineteen experts completed the consensus process between March and April 2023. In round 1, no statement failed to reach the predetermined consensus, resulting in 31 agreed statements. The statements were divided between general recommendations (14/31) and clinical scenarios (17/31). The scenarios were based on treatment-naïve NMOSD AQP4 positive patients (4/17); treatment-naive seronegative NMOSD patients (4/17); treatment switching (5/17) and safety (4/17).

CONCLUSIONS

Consensus recommendations were developed on the most important areas of NMOSD treatment by a panel of experts in LATAM. These statements are a valuable tool to guide decision-making and improve patient outcomes, serving as the foundation for developing standardized practice guidelines in our region.

Quantitative Contribution of Clinical Attacks to Residual Disability in Patients With AQP4-Antibody Neuromyelitis Optica Spectrum Disorder

BACKGROUND AND OBJECTIVES

Disease-related disability in aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD) is solely attributed to clinical attacks. However, few studies have assessed the relationship between attacks and residual disability in NMOSD. Thus, we aimed to quantify the contribution of clinical attacks to the residual disability in patients with AQP4-NMOSD.

METHODS

This retrospective observational single-center study enrolled patients from the Oxford National NMO Service, with the inclusion criteria as (1) AQP4-NMOSD diagnosis and (2) availability of at least 1 disability score (Expanded Disability Status Scale [EDSS] or logarithm of the minimum angle of resolution [LogMAR] score) recorded ≥6 months after attack (defined as residual disability). The outcome measures were EDSS and LogMAR scores. Univariable and multivariable linear mixed-effect models were used to quantify the effect of clinical relapses on the outcomes.

RESULTS

A total of 165 patients with AQP4-NMOSD (median onset age, 43 years, range 2-84; women, 140 [84.8%]; White European patients, 92 [55.8%]; African or African British patients, 40 [24.2%]; Asian or Asian British patients, 20 [12.1%]; multiracial or unknown racial patients, 13 [7.9%]) were included, with the median time of disability measurement since the last attack being 32 months (range 6-197). The mean increase in the EDSS score per relapse was 0.304 (95% CI 0.074-0.553, p < 0.001), with individual relapse phenotypes showing different effects: the transverse myelitis (TM) + optic neuritis (ON) phenotype contributed most, with an increase of 1.290 (95% CI 0.233-2.207, p = 0.017) per relapse, followed by brain plus other phenotypes (β = 0.782, 95% CI 0.029-1.03, p < 0.001) and isolated TM (β = 0.295, 95% CI 0.074-0.549, p < 0.001), while neither brain nor optic nerve relapse alone was associated with a residual change in the EDSS score. Older onset age was correlated with more severe motor disability where this mainly occurred early in the disease course while younger patients exhibited mild initial disability that worsened more significantly with relapses. Each ON attack led to a mean increase of 0.464 (95% CI 0.199-0.741, p < 0.001) in the LogMAR score. Race, sex, and timing of acute treatment did not significantly affect these disability outcomes (EDSS and LogMAR scores).

DISCUSSION

The quantitative contribution of relapse to the residual disability in patients with AQP4-NMOSD varies across phenotypes, and this relapse-related disability progression may also vary by the onset age. Although this retrospective single-center study may need validation in other data sets, these findings may help predict disability and provide a modeling tool for longer term disability in the cost-effective analysis of newer interventions.

Differential diagnosis and comparison of diagnostic algorithms in children and adolescents with autoimmune encephalitis in Spain: a prospective cohort study and retrospective analysis

BACKGROUND

The usefulness of current diagnostic approaches in children with suspected autoimmune encephalitis is unknown. We aimed to assess the diagnosis of autoimmune encephalitis in clinical practice and to compare the performance of two international diagnostic algorithms (one intended for patients of any age [general], the other intended for paediatric patients), with particular emphasis on the evaluation of patients with probable antibody-negative autoimmune encephalitis because this diagnosis suggests that immunotherapy should be continued or escalated but is difficult to establish.

METHODS

We did a prospective cohort study that included all patients (<18 years of age) with suspected autoimmune encephalitis recruited at 40 hospitals in Spain whose physicians provided clinical information every 6 months for 2 years or more. Neural antibody testing to confirm diagnosis of antibody-positive autoimmune encephalitis was done at Institut d'Investigacions Biomèdiques August Pi i Sunyer-Hospital Clínic, Barcelona. Patients were classified according to the most probable diagnosis at last follow-up into four prespecified categories. We used multivariable logistic analysis to assess a potential association between immunotherapy and outcome in individuals with probable antibody-negative autoimmune encephalitis. We also did a retrospective analysis of agreement, assessed with the kappa index, between diagnoses made according to the general and paediatric diagnostic algorithms.

FINDINGS

Between June 1, 2013, and May 31, 2021, 729 children (mean age 7·1 years [SD 4·9]; 383 boys [53%], 346 girls [47%]) with suspected autoimmune encephalitis were recruited. After a median follow-up of 36 months (IQR 26-60), patients were classified according to their most probable diagnosis: definite autoimmune encephalitis or well defined inflammatory or autoimmune disorders (n=230 [32%]); CNS infections (n=112 [15%]); inflammatory CNS disorders of unknown cause (n=81 [11%], including three (4%) with a novel Klüver-Bucy-like syndrome; and non-inflammatory disorders (n=306 [42%]), which were predominantly epileptic or psychiatric disorders (177 [58%] of 306). Neural antibodies were detected in 150 (65%) of 230 patients who had definite autoimmune encephalitis; 127 (85%) of these 150 individuals had antibodies to the NMDA receptor or myelin oligodendrocyte glycoprotein (MOG). Agreement between algorithms was excellent (kappa index 0·99, 95% CI 0·97-1·00) for the diagnosis of children with antibody-positive autoimmune encephalitis, good (0·59, 0·54-0·65) for recommendations of empiric immunotherapy, and poor (0·29, 0·21-0·37) for the diagnosis of probable antibody-negative autoimmune encephalitis. Compared with the general algorithm, the paediatric algorithm included more patients in the probable antibody-negative autoimmune encephalitis category (173 vs 41). These patients included some of those who had a diagnosis of CNS inflammatory disorder of unknown cause at the last follow-up (80 of 81 with the paediatric algorithm vs 31 of 81 with the general algorithm), who might have benefitted from immunotherapy, and some of those diagnosed with a non-inflammatory disorder at the last follow-up (47 of 306 with the paediatric algorithm vs six of 306 with the general algorithm), who did not need immunotherapy.

INTERPRETATION

About a third of children with suspected autoimmune encephalitis eventually had confirmation of this diagnosis, or diagnosis of another well defined inflammatory disorder. Frequent mimics of autoimmune encephalitis were infectious, epileptic, and psychiatric disorders. Both algorithms performed well in the diagnosis of antibody-positive autoimmune encephalitis, but the paediatric algorithm under-recognised definite autoimmune encephalitis that can occur without autoantibodies and might have overdiagnosed patients with probable antibody-negative autoimmune encephalitis. By contrast, the general algorithm might have underdiagnosed patients with probable antibody-negative autoimmune encephalitis. Given that the diagnosis of probable antibody-negative autoimmune encephalitis has treatment implications, inaccuracies on this diagnostic category leads to overuse or underuse of immunotherapy.

FUNDING

Instituto de Salud Carlos III, Fundació Clínic per la Recerca Biomèdica, The Edmond J Safra Foundation, and la Caixa Foundation.

TRANSLATION

For the Spanish translation of the abstract see Supplementary Materials section.

The prevalence, incidence, and clinical assessment of neuromyelitis optica spectrum disorder in patients with demyelinating diseases

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is characterised by recurrent attacks of optic neuritis and transverse myelitis. The purpose of this work was to identify the incidence and prevalence of NMOSD and its clinical characteristics in the population treated for demyelinating diseases in Western Mexico.

MATERIAL AND METHOD

A descriptive, retrospective study was carried out in the Department of Neurology, at the Sub-specialty Medical Unit, Specialties Hospital (known by its Spanish abbreviation UMAE-HE), of the National Western Medical Center (CMNO), Mexican Institute of Social Security (IMSS). A review of the electronic files for all patients with a diagnosis of NMOSD in 2019, was carried out in the State of Jalisco, Mexico.

RESULTS

Fifty-eight patients with NMOSD were included in the study. The incidence was 0.71/100 000 (CI 0.60-0.85) and the prevalence was 1.09/100 000 (CI 0.84-1.42). There were 79.3% women, and 20.6% were men (P = .01). All (100%) patients presented with anti-aquaporin-4 immunoglobulin G, and 89.6% showed seropositivity for anti-aquaporin-4 (CI 82.6-94.9). Magnetic resonance imaging was performed on 100% of patients, where 34.4% were normal, and 65.5% (38) abnormal, presenting with non-specific subcortical lesions (P = 0.04). The initial clinical presentation was optic neuritis (ON) in 58.6%; where 31.0% was bilateral ON, 20.7% was left ON, and 6.9% were right ON; transverse myelitis in 26.0%, area postrema syndrome (APS) in 10.3%, among others.

CONCLUSIONS

The incidence of NMOSD exceeds 0.71/100 000, the prevalence is low at 1.09/100 000, and NMOSD is predominantly found in women.

Sex ratio and age of onset in AQP4 antibody-associated NMOSD: a review and meta-analysis

BACKGROUND

Aquaporin-4 (AQP4) antibody-associated neuromyelitis optica spectrum disorder (NMOSD) is an antibody-mediated inflammatory disease of the central nervous system. We have undertaken a systematic review and meta-analysis to ascertain the sex ratio and mean age of onset for AQP4 antibody associated NMOSD. We have also explored factors that impact on these demographic data.

METHODS

A systematic search of databases was conducted according to the PRISMA guidelines. Articles reporting sex distribution and age of onset for AQP4 antibody-associated NMSOD were reviewed. An initially inclusive approach involving exploration with regression meta-analysis was followed by an analysis of just AQP4 antibody positive cases.

RESULTS

A total of 528 articles were screened to yield 89 articles covering 19,415 individuals from 88 population samples. The female:male sex ratio was significantly influenced by the proportion of AQP4 antibody positive cases in the samples studied (p < 0.001). For AQP4 antibody-positive cases the overall estimate of the sex ratio was 8.89 (95% CI 7.78-10.15). For paediatric populations the estimate was 5.68 (95% CI 4.01-8.03) and for late-onset cases, it was 5.48 (95% CI 4.10-7.33). The mean age of onset was significantly associated with the mean life expectancy of the population sampled (p < 0.001). The mean age of onset for AQP4 antibody-positive cases in long-lived populations was 41.7 years versus 33.3 years in the remainder.

CONCLUSIONS

The female:male sex ratio and the mean age of onset of AQP4 antibody-associated NMOSD are significantly higher than MS. The sex ratio increases with the proportion of cases that are positive for AQP4 antibodies and the mean age of onset increases with population life expectancy.

Case report: Overlap syndrome of neuromyelitis optica spectrum disorder with anti-Argonaute antibodies

Aquaporin-4 antibodies (AQP4-Abs) are a diagnostic marker for patients with a demyelinating disease called neuromyelitis optica spectrum disorder (NMOSD). Anti-Argonaute antibodies (AGO-Abs) present as potential biomarkers of the overlap syndrome between NMOSD and other autoimmune diseases. In this paper, we present the case of an adult woman with numbness, tingling, and burning sensations in her arms and subsequent bilateral internuclear ophthalmoplegia. Brain-cervical-thoracic magnetic resonance imaging (MRI) showed T2 hyperintensities in the dorsal brainstem and around the midbrain aqueduct and longitudinally transverse myelitis with homogeneous enhancement on gadolinium-enhanced MRI. The contemporaneous detection of AQP4- and AGO-Abs led to a definite diagnosis of overlap syndrome of NMOSD with AGO-Abs. The patient was treated with immunosuppressive agents, including corticosteroids and immunoglobulins, and achieved remission. This case highlights a novel phenotype of NMOSD with AGO-Abs overlap syndrome, which presents with relapsing brainstem syndrome and longitudinally extensive myelitis with acute severe neurological involvement. The promising prognosis of the disease could serve as a distinct clinical profile. Broad screening for antibodies against central nervous system autoimmune antigens is recommended in suspected patients with limited or atypical clinical manifestations.

Characteristics of recurrence in area postrema-onset NMO spectrum disorder - a retrospective cohort study

BACKGROUND

Neuromyelitis Optica Spectrum Disorder (NMOSD) is an inflammatory autoimmune disease with high risk of recurrence and disability, the treatment goal is a recurrence free state. Area postrema (AP) is one of the most common involved area of NMOSD, which may have a particular significance in the pathogenesis of NMOSD and clinical heterogeneity. Our study is to investigate the clinical and recurrent characteristics AP onset NMOSD patients.

METHODS

A retrospective study was done in a cohort of 166 AQP4-IgG seropositive NMOSD patients which were identified by the 2015 IPND criteria. The patients were divided into AP onset (APO-NMOSD) group and non-AP onset (NAPO-NMOSD) group based on the initial episode location. Clinical features and recurrence differences of two groups were compared.

RESULTS

The APO-NMOSD group and NAPO-NMOSD group had a population ratio of 24:142. APO-NMOSD patients were younger (34.6y VS 42.3y, P = 0.013), had lower EDSS at first episode (0.7 VS 4.2, p = 0.028) and last follow up (1.9 VS 3.3, p = 0.001), more likely to have multi-core lesions at the first attack (33.3% VS 9.2%, P = 0.001). Also, they had a higher annual recurrence rate (0.4 ± 0.28 VS 0.19 ± 0.25, P = 0.012). In natural course NMOSD patients without immunotherapy, APO-NMSOD had a shorter time of first relapse (P < 0.001) and higher annual recurrence rate (0.31 ± 0.22 VS 0.16 ± 0.26, P = 0.038) than NAPO-NMOSD. APO-NMOSD group also have a higher risk of having the first relapsing compared to optic neuritis onset-NMOSD (HR 2.641, 95% CI 1.427-4.887, p = 0.002) and myelitis onset-NMOSD group (HR 3.593, 95% CI 1.736-7.438, p = 0.001). Compared to NAPO-NMOSD, APO-NMOSD has a higher likelihood of brainstem recurrence (28.6% vs. 4.7%, p<0.001) during the first recurrence, while NAPO-NMOSD is more susceptible to optic nerve involvement (10.7% vs. 41.1%, p = 0.01).

CONCLUSION

AQP4-IgG seropositive NMOSD patients with AP onset are youngers and have higher risk of recurrence. Clinicians should pay attention to AP damage in NMOSD, as it indicates a potential risk of recurrence.

TRIAL REGISTRATION

Retrospectively registered.

Clinical features and visual prognosis of very late-onset neuromyelitis optica spectrum disorder-related optic neuritis

BACKGROUND

Very late-onset neuromyelitis optica spectrum disorder-related optic neuritis is limited to a few case reports.

OBJECTIVE

To investigate the clinical features and visual prognosis of very late-onset neuromyelitis optica spectrum disorder-related optic neuritis.

METHODS

This study evaluated 22 patients with first-onset optic neuritis and fulfilled the 2015 diagnosis criteria for neuromyelitis optica spectrum disorders.

RESULTS

The mean age at optic neuritis onset was 73.91 ± 4.71 (range: 70-82) years with a female predominance (81.8%; ratio: 4.5:1). Antinuclear antibody seropositivity and seronegativity were identified in 12 (55.5%) and 10 (45.5%) patients, respectively. Severe visual loss persisted in 19 (19/42, 45.3%) eyes at the last follow-up. Although patients with antinuclear antibody seropositivity had a significantly higher frequency of attacks (P = 0.015), but they had a longer median time to reach severe visual loss (37 vs. 26 months; log-rank test, P = 0.023). Multivariate logistic regression analysis revealed antinuclear antibody seropositivity (hazard ratio = 4.849, 95% confidence interval: 1.309-17.965, P = 0.018) as a good predictor of visual acuity improvement.

CONCLUSION

Patients with very late-onset neuromyelitis optica spectrum disorder-related optic neuritis may develop severe optic neuritis, and those with antinuclear antibody seronegativity have a similar clinical presentation but worse outcome than those with seropositivity.

Real-world management of patients with neuromyelitis optica spectrum disorder using satralizumab: Results from a Japanese claims database

BACKGROUND

Satralizumab, a humanized anti-interleukin-6 receptor monoclonal antibody, has been approved globally for the treatment of neuromyelitis optica spectrum disorder (NMOSD), based on positive results from two randomized, double-blind, phase 3 studies: SAkuraSky (NCT02028884) and SAkuraStar (NCT02073279). There remains an unmet need to understand the real-world management of NMOSD, especially in patients undergoing tapering of concomitant therapy. We examined real-world treatment patterns, including concomitant glucocorticoids and immunosuppressants, and relapse in satralizumab-treated patients with NMOSD, using a Japanese administrative hospital claims database.

METHODS

We used retrospective data from the Medical Data Vision hospital-based administrative claims database. The index date was the date of first satralizumab prescription and the study period was set between August 2018 and March 2022. Patients were included in the overall population if they had a first prescription for satralizumab between August 2020 and March 2022, an International Classification of Disease, Version10 code of G36.0 prior to March 2022, and were observable for ≥90 days prior to the index date. The primary endpoint was the percentage of patients with relapse-free reduction of oral glucocorticoids to 0 mg/day at 360 days of continued satralizumab treatment. Secondary endpoints included time to relapse, number of relapses after the index date while being on continuous satralizumab treatment, annualized relapse rate before and after the index date, and concomitant medication use. Relapse and dose reduction were identified using definition specifically developed for this study.

RESULTS

Of the 131 patients included in the overall population, most were female (90.8 %), aged 18-65 years (75.6 %), and were prescribed oral glucocorticoids (93.1 %). Azathioprine (19.1 %) and tacrolimus, a calcineurin inhibitor (18.3 %), were the most common immunosuppressants at index date. Six (4.6 %) patients had a history of biologic use (tocilizumab, 1 [0.8 %]; eculizumab, 5 [3.8 %]). Among 111 patients observable for 360 days pre-index, there were 0.6 ± 0.8 (mean ± SD) relapses during 360 days before the index date. The median (interquartile range) duration of satralizumab exposure was 197.0 (57.0-351.0) days. Most (125/131; 95.4 %) patients were relapse-free post-index; 6 (4.6 %) patients relapsed within 90 days after the index date, of which 2 had the first relapse within 7 days after the index date. Among 21 patients with 360-day follow-up, 6 (28.6 %) patients were on 0 mg/day dose of glucocorticoid prescription without relapse 360 days post-index. Of these 6 patients, 2 had no prescription of oral glucocorticoids at the index date and remained glucocorticoid- and relapse-free 360 days after the index date.

CONCLUSION

These real-world data support the phase 3 clinical trials. Our results, over a median duration of satralizumab exposure of 197.0 days, showed that a majority (125/131, 95.4 %) of patients were relapse-free after initiating satralizumab treatment. The number of glucocorticoid-free patients without relapse increased over time under continuous satralizumab prescription. Further studies are needed to confirm if satralizumab can be used as a potential immunosuppressant- and glucocorticoid-sparing agent.

Predicting time to serologic diagnosis of AQP4+ NMOSD based on clinical factors and social determinants of health

BACKGROUND

Early serologic diagnosis and initiation of targeted therapy are associated with better outcomes in aquaporin-4 IgG positive (AQP4+) neuromyelitis optica spectrum disorder (NMOSD).

OBJECTIVE

To determine predictors of time to serologic diagnosis of AQP4+ NMOSD.

METHODS

In CANOPTICS, a multi-centre, Canadian cohort study of NMOSD, we retrospectively evaluated time from the first clinical attack to first positive AQP4-IgG serology. We used a multivariable negative binomial regression model to evaluate possible predictors of time to diagnosis.

RESULTS

We identified 129 participants with AQP4+ NMOSD from 7 centres. Diagnostic delay of >1 month was observed in 82 (63.6 %). Asian compared to European (White) ethnicity (IRR:0.40, 95 % CI:0.21-0.78), female sex (IRR:0.56, 95 % CI:0.32-0.99), later calendar year (IRR:0.84, 95 % CI:0.81-0.86), and hospitalization for the first attack (IRR:0.35, 95 % CI:0.20-0.62) were associated with shorter times to serologic diagnosis. We did not observe any overall effect of Afro-Caribbean ethnicity, but in exploratory analyses, Afro-Caribbean individuals with low income had longer times to diagnosis.

CONCLUSION

More than 60 % of patients with NMOSD experienced delays to AQP4-IgG serologic diagnosis in this cohort. Given evidence of more adverse long-term outcomes in Afro-Caribbean individuals with NMOSD, intersectional effects of ethnicity and social determinants of health merit further study.

Patterns of neuromyelitis optica spectrum disorder attacks in different age groups and sexes depending on the status of immunosuppressive therapy: A retrospective cohort study

BACKGROUND AND PURPOSE

The association between onset age and sex with relapse risk in neuromyelitis optica spectrum disorder (NMOSD) remains inconclusive. We aimed to describe the clinical features of patients with NMOSD in different age groups and sexes and to analyse relapse characteristics pre- and post-immunosuppressive therapy (IST).

METHODS

Patients with NMOSD were retrospectively reviewed from our clinical centre's database. Demographic and clinical data, attack presentation, and disease course pre- and post-IST were investigated. We also analysed the effect of onset age on the annualized relapse rate and relapse risk according to sex and IST status. Interactions on the additive scale between onset age and sex were analysed. A restricted cubic spline was used to analyse potential nonlinear correlations. Longitudinal changes in the Expanded Disability Status Scale score across NMOSD attacks were analysed using linear mixed-effect models.

RESULTS

In total, 533 patients experienced 1394 attacks pre-IST and 753 relapses post-IST. Older age at onset was correlated with more myelitis attacks but fewer optic neuritis attacks, with no sex-related differences in attack presentation. Pre-IST, relapse risk increased with age at onset in women, while a U-shaped correlation between onset age and relapse risk was found in men. Post-IST, an inverted U-shaped association between the predicted relapse risk and onset age was observed in women. Conversely, a negative correlation between the predicted relapse risk and onset age was found in men. Overall, a higher ratio of myelitis attacks was found post-IST.

CONCLUSIONS

Patients of different onset ages and sexes had different relapse patterns before and after IST.

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.

Clinical and demographic characteristics of patients with NMOSD: a longitudinal retrospective analysis of a Slovak cohort of 63 patients

BACKGROUND

Neuromyelitis optica spectrum disorders (NMOSD) are autoantibody-mediated inflammatory diseases of the central nervous system predominantly targeting optic nerves and the spinal cord. Two distinct phenotypes are recognized based on the presence of serum aquaporin-4 (AQP4-IgG) antibodies. However, contrasting clinical course patterns have been identified between AQP4-IgG-positive and AQP4-IgG-negative patients.

AIMS

This study aimed to present demographic and clinical characteristics of patients with NMOSD in Slovakia and to evaluate the significance of differences between AQP4-IgG-seropositive and AQP4-IgG-seronegative patients.

METHODS

We performed a longitudinal multi-centric retrospective study and analysed the clinical and demographic characteristics of a cohort of 63 Slovak NMOSD patients.

RESULTS

Eighty-six percent of patients were women, and ninety-four patients were Caucasian. The median age at diagnosis was 37 years. The most frequent initial manifestations were optic neuritis (47.6% of patients) and transverse myelitis (39.7% of patients). The median EDSS score deteriorated from the initial 3.0 to 4.0 at the last follow-up. Sixty-eight percent of patients were AQP4-IgG positive; 10% of patients were MOG-IgG positive; 27% of patients had no NMOSD-specific antibodies detected. There was a higher prevalence of autoimmune thyroiditis among AQP4-IgG-positive patients (25.6%) compared to AQP4-IgG-negative patients (0%) (p = 0.01).

CONCLUSION

This study provides a detailed overview of the clinical and demographic characteristics of NMOSD based on a retrospective analysis of a Slovak cohort of 63 NMOSD patients and extends information provided by similar recently published studies. The most important finding is that there is a high prevalence of autoimmune thyroiditis among AQP4-IgG-negative patients (25%).

Clinical Usefulness of a Cell-based Assay for Detecting Myelin Oligodendrocyte Glycoprotein Antibodies in Central Nervous System Inflammatory Disorders

Background

The clinical implications of myelin oligodendrocyte glycoprotein autoantibodies (MOG-Abs) are increasing. Establishing MOG-Ab assays is essential for effectively treating patients with MOG-Abs. We established an in-house cell-based assay (CBA) to detect MOG-Abs to identify correlations with patients' clinical characteristics.

Methods

We established the CBA using HEK 293 cells transiently overexpressing full-length human MOG, tested it against 166 samples from a multicenter registry of central nervous system (CNS) inflammatory disorders, and compared the results with those of the Oxford MOG-Ab-based CBA and a commercial MOG-Ab CBA kit. We recruited additional patients with MOG-Abs and compared the clinical characteristics of MOG-Ab-associated disease (MOGAD) with those of neuromyelitis optica spectrum disorder (NMOSD).

Results

Of 166 samples tested, 10 tested positive for MOG-Abs, with optic neuritis (ON) being the most common manifestation (4/15, 26.7%). The in-house and Oxford MOG-Ab CBAs agreed for 164/166 (98.8%) samples (κ=0.883, P<0.001); two patients (2/166, 1.2%) were only positive in our in-house CBA, and the CBA scores of the two laboratories correlated well (r=0.663, P<0.001). The commercial MOG-Ab CBA kit showed one false-negative and three false-positive results. The clinical presentation at disease onset differed between MOGAD and NMOSD; ON was the most frequent manifestation in MOGAD, and transverse myelitis was most frequent in NMOSD.

Conclusions

The in-house CBA for MOG-Abs demonstrated reliable results and can potentially be used to evaluate CNS inflammatory disorders. A comprehensive, long-term study with a large patient population would clarify the clinical significance of MOG-Abs.

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.

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.

Role of serostatus in pediatric neuromyelitis optica spectrum disorders: A nationwide multicentric study

BACKGROUND

Neuromyelitis optica spectrum disorders (NMOSD) are immune-mediated inflammatory disorders of the central nervous system (CNS) mostly presenting as optic neuritis and acute myelitis. NMOSD can be associated with seropositivity for aquaporin 4 antibody (AQP4 IgG), myelin oligodendrocyte glycoprotein antibody (MOG IgG), or can be seronegative for both. In this study, we retrospectively examined our seropositive and seronegative pediatric NMOSD patients.

METHOD

Data were collected from all participating centres nationwide. Patients diagnosed with NMOSD were divided into three subgroups according to serology: AQP4 IgG NMOSD, MOG IgG NMOSD, and double seronegative (DN) NMOSD. Patients with at least six months of follow-up were compared statistically.

RESULTS

The study included 45 patients, 29 female and 16 male (ratio:1.8), mean age 15.16 ± 4.93 (range 5.5-27) years. Age at onset, clinical manifestations, and cerebrospinal fluid findings were similar between AQP4 IgG NMOSD (n = 17), MOG IgG NMOSD (n = 10), and DN NMOSD (n = 18) groups. A polyphasic course was more frequent in the AQP4 IgG and MOG IgG NMOSD groups than DN NMOSD (p = 0.007). The annualized relapse rate and rate of disability were similar between groups. Most common types of disability were related to optic pathway and spinal cord involvement. Rituximab in AQP4 IgG NMOSD, intravenous immunoglobulin in MOG IgG NMOSD, and azathioprine in DN NMOSD were usually preferred for maintenance treatment.

CONCLUSION

In our series with a considerable number of double seronegatives, the three major serological groups of NMOSD were indistinguishable based on clinical and laboratory findings at initial presentation. Their outcome is similar in terms of disability, but seropositive patients should be more closely followed-up for relapses.

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.

Pearls & Oy-sters: Tumefactive Demyelinating Lesions With MOG Antibodies Preceding Late Infantile Metachromatic Leukodystrophy

The development of acute neurologic dysfunction associated with tumefactive demyelinating lesions and mild diffuse involvement of the corpus callosum has been described in children as a sentinel event that may allow diagnosis of juvenile metachromatic leukodystrophy (MLD) at an early and potentially treatable stage. We report a child who developed this clinico-radiologic pattern associated with myelin oligodendrocyte glycoprotein antibodies several months before the onset of progressive symptoms of late infantile MLD.

Treatment and Relapse Prevention of Typical and Atypical Optic Neuritis

Optic neuritis (ON) is an inflammatory condition involving the optic nerve. Several important typical and atypical ON variants are now recognized. Typical ON has a more favorable prognosis; it can be idiopathic or represent an early manifestation of demyelinating diseases, mostly multiple sclerosis (MS). The atypical spectrum includes entities such as antibody-driven ON associated with neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody disease (MOGAD), chronic/relapsing inflammatory optic neuropathy (CRION), and sarcoidosis-associated ON. Appropriate and timely diagnosis is essential to rapidly decide on the appropriate treatment, maximize visual recovery, and minimize recurrences. This review paper aims at presenting the currently available state-of-the-art treatment strategies for typical and atypical ON, both in the acute phase and in the long-term. Moreover, emerging therapeutic approaches and novel steps in the direction of achieving remyelination are discussed.

CSF GFAP levels in double seronegative neuromyelitis optica spectrum disorder: no evidence of astrocyte damage

Background

Despite rigorous confirmation with reliable assays, some individuals showing the neuromyelitis optica spectrum disorder (NMOSD) phenotype remain negative for both aquaporin-4 (AQP4) and myelin oligodendrocyte glycoprotein (MOG) antibodies.

Objective

We aimed to investigate whether double seronegative NMOSD (DN-NMOSD) and NMOSD with AQP4 antibody (AQP4–NMOSD) share the same pathophysiological basis, astrocytopathy, by measurement of cerebrospinal fluid (CSF) glial fibrillary acidic protein (GFAP) levels as a marker of astrocyte damage.

Methods

Seventeen participants who (1) satisfied the 2015 diagnostic criteria for NMOSD, and (2) tested negative for AQP4 and MOG antibodies confirmed with repeated cell-based assays, and (3) had available CSF samples obtained at the point of clinical attacks, were enrolled from 4 medical centers (South Korea, Germany, Thailand, and Denmark). Thirty age-matched participants with AQP4–NMOSD, 17 participants with MOG antibody associated disease (MOGAD), and 15 participants with other neurological disorders (OND) were included as controls. The concentration of CSF GFAP was measured using enzyme-linked immunosorbent assay.

Results

CSF GFAP levels in the DN-NMOSD group were significantly lower than those in the AQP4–NMOSD group (median: 0.49 versus 102.9 ng/mL; p < 0.001), but similar to those in the OND (0.25 ng/mL) and MOGAD (0.39 ng/mL) control groups. The majority (90% (27/30)) of participants in the AQP4–NMOSD group showed significantly higher CSF GFAP levels than the highest level measured in the OND group, while no participant in the DN-NMOSD and MOGAD groups did.

Conclusions

These results suggest that DN-NMOSD has a different underlying pathogenesis other than astrocytopathy, distinct from AQP4–NMOSD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12974-022-02450-w.

A Longitudinal Comparison of the Recovery Patterns of Optic Neuritis with MOG Antibody-Seropositive and AQP4 Antibody-Seropositive or -Seronegative for Both Antibodies

In this study, the aim is to compare the recovery pattern among patients with acute myelin oligodendrocyte glycoprotein antibody-seropositive optic neuritis (MOG-Ab + ON) attacks and aquaporin-4 antibody-seropositive ON (AQP4-Ab + ON) or -seronegative ON. At the onset of the first-ever ON attack, the thickness of RNFL (RNFLt) in the MOG-Ab + ON group was significantly thicker than others ( $P<0.05$ ), while visual function damage was not significantly different to other groups. One month to six months after onset, the MOG-Ab + ON group showed significantly better visual function ( $P<0.05$ ) than the other two groups, while the RNFLt showed no significant difference among the three groups ( $P>0.05$ ). MOG-Ab + ON and AQP4-Ab + ON groups showed rapid recovery in the first month and then plateaued. The annual relapse rate was significantly higher in MOG-Ab + ON and AQP4-Ab + ON groups than seronegative ON. The relapse interval of the MOG-Ab + ON group (9.00 ± 7.86 months) was significantly shorter than that of the AQP4-Ab + ON group (45.76 ± 37.82 months) ( $P<0.05$ ) but showed no significant difference from that of the seronegative ON group ( $P>0.05$ ). To sum up, the recovery patterns were different among these three types of ON. RNFLt was not parallel to the recovery of visual function among these types of ON. MOG-Ab + ON had the mildest visual function damage but the most substantial RNFL changes, while AQP4-Ab + ON suffered the worst function damage. MOG-Ab + ON had a similar relapse rate as AQP4-Ab + ON but a shorter interval, indicating that relapse prevention was necessary and should be initiated as early as possible.

Clinical and prognostic aspects of patients with the Neuromyelitis Optica Spectrum Disorder (NMOSD) from a cohort in Northeast Brazil

Introduction

Neuromyelitis optica spectrum disorders (NMOSD) is a rare inflammatory and demyelinating disease of the central nervous system (CNS) more frequent in women and Afro-descendants. No previous epidemiological or prognostic study has been conducted in the region of the state of Bahia, Brazilian Northeast.

Objective

To evaluate clinical and prognostic aspects in patients with NMOSD from a cohort in northeastern Brazil.

Material and methods

A single-center retrospective study was conducted with consecutive patients diagnosed with NMOSD. Clinical and epidemiological characteristics were described. The degree of disability was expressed by the Expanded Disability Status Scale (EDSS). Worsening disability were analyzed through negative binomial regression adjusted for disease duration.

Results

Ninety-one patients were included, 72 (79.1%) female and 67 (73.6%) afro descendants. Mean age at onset was 36 (± 14) years and 73.3% were anti-aquaporin-4 antibody positive. Isolated transverse myelitis (32.9%) and isolated optic neuritis (22.4%) were the most frequent initial clinical syndromes. After multivariate analysis, optic neuritis (RR = 0.45; 95% CI = 0.23 – 0.88; p = 0.020) and dyslipidemia (RR = 0.40; 95% CI = 0.20 – 0.83; p = 0.014) were associated with slower disease progression. Area postrema involvement (RR = 6.70; 95% CI = 3.31 – 13.54; p < 0.001) and age at onset (RR = 1.03; 95% CI = 1.01 – 1.05; p = 0.003) were associated with faster disease progression.

Conclusions

In the first clinical and prognostic study in northeastern Brazil, we identified area postrema involvement, age at onset, optic neuritis at fist syndrome and dyslipidemia as the main prognostic factors associated with disease progression.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02621-5.

• Isolated transverse myelitis was the most frequent initial clinical syndrome.

• Optic neuritis as first clinical syndrome was independently associated with better prognostic.

• Age at onset were associated with faster disease progression.

• Hashimoto's thyroiditis was the most frequent autoimmune disease in NMOSD.

A Comparative Analysis of Clinical and Imaging Features of Aquaporin 4 (AQP4) Antibody Positive, Myelin Oligodendrocyte Glycoprotein (MOG) Antibody Positive and Double Seronegative Subtypes of Neuro Myelitis Optica Spectrum Disorder (NMOSD)

Objectives

Study was conducted with aim of comparing subtypes types of NMOSD based on serology.

Methods

In this retrospective study, patients ≥18 years were included satisfying IPND 2015 criteria. Three groups were created based on seropositivity for AQP4 antibody, MOG antibody or double seronegative. Demographic, clinical and imaging were compared using regression analysis.

Results

Forty-six patients, 28 (60.9%) AQP4+, 11 (23.9%) MOG + and remaining 7 (15.2%) double seronegative were included. Thirty-seven patients (80.4%) had presenting symptoms localized to optic nerve and/or cord [AQP4 + 22 (78.5%), MOG + 9 (81.8%) and double seronegative 6 (85.7%)]. Presentation with bilateral optic neuritis was more common in AQP4- patients. Twenty (86.8%) out of the 23 patients who had relapsing disease localized to optic nerve and/or spinal cord [AQP4 + 13/14 (92.8%), MOG + 3/5 (60%) and double seronegative 4/4 (100%)]. Relapses were more common in AQP4+ (77% vs 12% vs10%). In AQP4 negative group disability (EDSS 4.2 vs 3.3) and progression index was relatively less (1.6 vs 1.1). CSF pleocytosis (38.8% vs 17.9%) and raised proteins (66.6% vs 32.1%) were also more common. Optic nerve MRI (>50% optic nerve and chiasma involvement) was more commonly abnormal in AQP4 negative (52.9% vs 31.2%). Regression analysis revealed females to be significantly higher in AQP4 positive NMOSD (89.3%) when compared to MOG positive (36.4%) and double seronegative (42.9%).

Conclusion

Gender was the only significant difference between the three groups. There was trend towards greater disability and more relapses in AQP4 + groups.

Aquaporin-4-Positive Triple-Negative Breast Cancer Presenting with Paraneoplastic Neuromyelitis Optica Spectrum Disorder

INTRODUCTION

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory central nervous system disorder that preferentially affects the optic nerve and the spinal cord. Although NMOSD is more commonly an idiopathic autoimmune condition associated with antibodies against aquaporin-4 (AQP4)-IgG, the disease may also occur as a paraneoplastic syndrome in rare instances. In these cases, the expression of AQP4 by the tumor is likely the trigger of the autoimmune response.

CASE PRESENTATION

We describe the case of a 32-year-old woman who presented with progressive tetraparesis, cranial involvement, respiratory failure, and spinal cord MRI compatible with longitudinally extensive transverse myelitis, few days after being diagnosed with a T3N1M0 triple-negative right breast cancer. Due to the history of concurrent breast cancer and after ruling out metastatic spinal cord involvement, the possibility of a paraneoplastic origin was raised. AQP4-IgG were found in the serum and CSF by cell-based assay, confirming the diagnosis of NMOSD. The patient was treated with corticosteroids, plasma exchange, and rituximab. Concomitantly, breast cancer therapy was started with an adapted neoadjuvant chemotherapy scheme based on carboplatin and paclitaxel. An initial slight improvement slowed down; so, a right mastectomy with lymphadenectomy was performed. Expression of AQP4 was demonstrated in the tumor. The patient presented a significant neurological improvement after combined treatment regaining muscular balance and strength in upper and lower extremities.

CONCLUSION

NMOSD may have a paraneoplastic origin associated with breast cancer and the importance of its early detection since the combination of tumoral and immunosuppressive therapy may improve the patient's prognosis.

[Epidemiology of neuromyelitis optica spectrum. New and old challenges]

INTRODUCTION

This epidemiological review on neuromyelitis optica spectrum disorder (NMOSD) focuses on describing the methodologies employed in studies conducted under the 2015 NMOSD criteria and the studies conducted in Spain and Latin America, as well as examining factors related to the prognosis of the disease.

DEVELOPMENT

The methodology used in the studies varies essentially in the application of different diagnostic criteria, sources of records, antibody detection techniques and standardisation methods. However, in general terms, NMOSD is distributed worldwide with an incidence/prevalence that is higher in women than in men, and in Asian and African-American countries than in Western countries. The frequency increases in parallel to age, with a peak incidence/prevalence in the 40-59 age range. The Latin American population has particular epidemiological characteristics linked to its racial and genetic mix. Finally, epidemiological variables, such as belonging to the black race, being of older age at onset and being female, are associated with a worse functional prognosis.

CONCLUSIONS

Epidemiological data on NMOSD vary from one study to another, largely due to discrepancies in the methodological designs. Although Latin American studies are scarce, the findings described are associated with their ethnic mix. The homogenisation of criteria and the use of similar diagnostic techniques and standardisation methods must be implemented for the correct study of the epidemiology of NMOSD.

Treatment response, risk of relapse and clinical characteristics of Taiwanese patients with neuromyelitis optica spectrum disorder

BACKGROUND/PURPOSE

The long-term disease course and efficacy of maintenance therapies have rarely been investigated in Asian patients with neuromyelitis optica spectrum disorder (NMOSD).

METHODS

Medical records of patients fulfilling the 2015 International Consensus Diagnostic Criteria for NMOSD at three medical centers in Taiwan were systematically analyzed. Linear regression analysis was performed to investigate factors related to annualized relapse rate (ARR); survival analysis was used to estimate the relapse-free intervals among therapies.

RESULTS

A total of 557 relapses affecting 648 regions (202 optic neuritis, 352 acute myelitis, and 94 brain syndromes) in 204 patients were analyzed during a follow-up period of 69.5 months (range, 1-420). Up to 36.1% of myelitis-onset patients and 24.0% of optic neuritis-onset patients exhibited a limited form disease, defined as having one or more relapses confined to the same region. The median ARR was significantly lower in patients with limited form disease than those with relapses involving multiple regions (0.30 vs. 0.47, respectively). An older age at disease onset was associated with a lower ARR (p = 0.023). Kaplan-Meier analysis showed that the estimated time (months) to next relapse was longest in rituximab-treatment group (58.0 ± 13.2), followed by immunosuppressant (48.5 ± 4.8) or prednisone (29.6 ± 4.6) groups, and shortest in those without maintenance therapy (27.6 ± 4.2) (p = 8.1 × 10^-7).

CONCLUSION

Limited form disease and older age at disease onset are associated with a lower relapse rate in NMOSD. Compared to no maintenance therapy, rituximab and immunosuppressant significantly reduce the relapse risks.

Health Disparities, Inequities, and Social Determinants of Health in Multiple Sclerosis and Related Disorders in the US: A Review

Importance

There is empirical evidence that social determinants of health (SDOH) impact health outcomes in Black and Hispanic and Latinx individuals in the US. Recently, SDOH have risen to the top as essential intervention targets that could help alleviate racial and ethnic disparities. Neuromyelitis optica spectrum disorder (NMOSD) disproportionately affects Black individuals, and multiple sclerosis (MS) has seen a recent shift in select racial groups. It is unclear to what degree SDOH have been investigated and contribute to racial and ethnic health disparities and inequities.

Observations

This narrative review provides a contemporary synthesis of SDOH associated with racial and ethnic health disparities and inequities in MS, NMOSD, and other autoimmune disorders, such as myelin oligodendrocyte glycoprotein antibody (MOG-Ab)-associated disease. These immune-mediated neurological diseases were chosen for their capacity to be a high burden to society and because of complementary SDOH-associated challenges among minority populations. A paucity of research addressing inequities and the role of SDOH in MS and NMOSD was noted despite findings that Black individuals have a higher risk of developing MS or NMOSD and associated mortality compared with White individuals. Greater health disparities were also found for those with lower income and education, lower health literacy, and negative illness perceptions in MS. No studies in MOG-Ab disorders were found.

Conclusions and Relevance

Increased efforts are needed to better understand the role of SDOH in racial and ethnic health disparities and inequities in MS, NMOSD, and emerging autoimmune disorders. This includes developing research frameworks aimed at understanding the magnitude and interrelationships of SDOH to better develop system-based multilevel interventions across the spectrum of care for these neurological conditions.

Retinal optical coherence tomography and magnetic resonance imaging in neuromyelitis optica spectrum disorders and MOG-antibody associated disorders: an updated review

INTRODUCTION

Neuromyelitis optica spectrum disorders (NMOSD) and myelin oligodendrocyte glycoprotein IgG antibody-associated disorders (MOGAD) comprise two groups of rare neuroinflammatory diseases that cause attack-related damage to the central nervous system (CNS). Clinical attacks are often characterized by optic neuritis, transverse myelitis, and to a lesser extent, brainstem encephalitis/area postrema syndrome. Retinal optical coherence tomography (OCT) is a non-invasive technique that allows for in vivo thickness quantification of the retinal layers. Apart from OCT, magnetic resonance imaging (MRI) plays an increasingly important role in NMOSD and MOGAD diagnosis based on the current international diagnostic criteria. Retinal OCT and brain/spinal cord/optic nerve MRI can help to distinguish NMOSD and MOGAD from other neuroinflammatory diseases, particularly from multiple sclerosis, and to monitor disease-associated CNS-damage.

AREAS COVERED

This article summarizes the current status of imaging research in NMOSD and MOGAD, and reviews the clinical relevance of OCT, MRI and other relevant imaging techniques for differential diagnosis, screening and monitoring of the disease course.

EXPERT OPINION

Retinal OCT and MRI can visualize and quantify CNS damage in vivo, improving our understanding of NMOSD and MOGAD pathology. Further efforts on the standardization of these imaging techniques are essential for implementation into clinical practice and as outcome parameters in clinical trials.

CNS Demyelinating Attacks Requiring Ventilatory Support With Myelin Oligodendrocyte Glycoprotein or Aquaporin-4 Antibodies

Background and Objective

Severe attacks of myelin oligodendrocyte glycoprotein (MOG) antibody–associated disorder (MOGAD) and aquaporin-4 (AQP4) antibody–positive neuromyelitis optica spectrum disorder (AQP4-NMOSD) may require ventilatory support, but data on episodes are limited, particularly for MOGAD. We sought to compare the frequency, characteristics, and outcomes of MOGAD and AQP4-NMOSD attacks requiring ventilatory support.

Methods

This retrospective descriptive study identified Mayo Clinic patients (January 1, 1996–December 1, 2020) with MOGAD or AQP4-NMOSD and an attack requiring noninvasive or invasive ventilation at Mayo Clinic or an outside facility by searching for relevant terms in their electronic medical record. Inclusion criteria were (1) attack-related requirement for noninvasive (bilevel positive airway pressure or continuous positive airway pressure) or invasive respiratory support (mechanical ventilation); (2) MOG or AQP4 antibody positivity with fulfillment of MOGAD and AQP4-NMOSD clinical diagnostic criteria, respectively; and (3) sufficient clinical details. We collected data on demographics, comorbid conditions, indication for and duration of respiratory support, MRI findings, treatments, and outcomes. The races of those with attacks requiring respiratory support were compared to those without such attacks in MOGAD and AQP4-NMOSD.

Results

Attacks requiring ventilatory support were similarly rare in patients with MOGAD (8 of 279, 2.9%) and AQP4-NMOSD (11 of 503 [2.2%]) (p = 0.63). The age at attack (median years [range]) (MOGAD 31.5 [5–47] vs AQP4-NMOSD 43 [14–65]; p = 0.01) and percentage of female sex (MOGAD 3 of 8 [38%] vs AQP4-NMOSD 10 of 11 [91%]; p = 0.04) differed. The reasons for ventilation differed between MOGAD (inability to protect airway from seizure, encephalitis or encephalomyelitis with attacks of acute disseminated encephalomyelitis 5 [62.5%] or unilateral cortical encephalitis 3 [37.5%]) and AQP4-NMOSD (inability to protect airway from cervical myelitis 9 [82%], rhombencephalitis 1 [9%], or combinations of both 1 [9%]). Median ventilation duration for MOGAD was 2 days (range 1–7 days) vs 19 days (range 6–330 days) for AQP4-NMOSD (p = 0.01). All patients with MOGAD recovered, but 2 of 11 (18%) patients with AQP4-NMOSD died of the attack. For AQP4-NMOSD, Black race was overrepresented for attacks requiring ventilatory support vs those without these episodes (5 of 11 [45%] vs 88 of 457 [19%]; p = 0.045).

Discussion

Ventilatory support is rarely required for MOGAD and AQP4-NMOSD attacks, and the indications differ. Compared to MOGAD, these attacks in AQP4-NMOSD may have higher morbidity and mortality, and those of Black race were more predisposed, which we suspect may relate to socially mediated health inequality.

Treatment of Neuromyelitis Optica Spectrum Disorders

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune central nervous system (CNS) inflammatory disorder that can lead to serious disability and mortality. Females are predominantly affected, including those within the reproductive age. Most patients develop relapsing attacks of optic neuritis; longitudinally extensive transverse myelitis; and encephalitis, especially brainstem encephalitis. The majority of NMOSD patients are seropositive for IgG autoantibodies against the water channel protein aquaporin-4 (AQP4-IgG), reflecting underlying aquaporin-4 autoimmunity. Histological findings of the affected CNS tissues of patients from in-vitro and in-vivo studies support that AQP4-IgG is directly pathogenic in NMOSD. It is believed that the binding of AQP4-IgG to CNS aquaporin-4 (abundantly expressed at the endfoot processes of astrocytes) triggers astrocytopathy and neuroinflammation, resulting in acute attacks. These attacks of neuroinflammation can lead to pathologies, including aquaporin-4 loss, astrocytic activation, injury and loss, glutamate excitotoxicity, microglial activation, neuroinflammation, demyelination, and neuronal injury, via both complement-dependent and complement-independent pathophysiological mechanisms. With the increased understanding of these mechanisms underlying this serious autoimmune astrocytopathy, effective treatments for both active attacks and long-term immunosuppression to prevent relapses in NMOSD are increasingly available based on the evidence from retrospective observational data and prospective clinical trials. Knowledge on the indications and potential side effects of these medications are essential for a clear evaluation of the potential benefits and risks to NMOSD patients in a personalized manner. Special issues such as pregnancy and the coexistence of other autoimmune diseases require additional concern and meticulous care. Future directions include the identification of clinically useful biomarkers for the prediction of relapse and monitoring of the therapeutic response, as well as the development of effective medications with minimal side effects, especially opportunistic infections complicated by long-term immunosuppression.

Monoclonal Antibody Therapy in Neuromyelitis Optica Spectrum Disorders: a Meta-analysis of Randomized Control Trials

Background: To update the efficacy and safety data of monoclonal antibodies for the treatment of neuromyelitis optica spectrum disorders (NMOSD) and explore the differences in the effect of treatment between patients seropositive and seronegative for AQP4-IgG.

METHODS

PubMed, Embase, and the Cochrane Library published up to July 2020 were searched for randomized controlled trials (RCTs) of monoclonal antibodies treatment (mAb) in patients with NMOSD. The primary outcome was the hazard ratio (HR) for relapse. The secondary outcomes included Expanded Disability Status Scale (EDSS) changes from baseline, adverse events (AEs), and serious adverse events (SAEs). A random-effects model was applied for the effect of heterogeneity among trials.

RESULTS

We included 603 patients (monoclonal antibody group, n=382, and control group, n=221) from seven RCTs. There were fewer relapses in the mAb group (HR=0.32, 95% CI: 0.23-0.46, p<0.001), as well as in the AQP4-IgG-seropositive patients (HR=0.18, 95% CI: 0.10-0.32, p<0.001), but not in AQP4-IgG-seronegative NMOSD. Similar results were observed when considering satralizumab only. The mAb had no impact on the changes in EDSS scores from baseline (WMD=-0.21, 95% CI: -0.50-0.09, p=0.176). The mAb did not lead to a higher frequency of AEs (OR=1.18, 95% CI: 0.70-1.98, p=0.529) or SAEs (OR=0.99, 95% CI: 0.63-1.56, p=0.975) compared with the control group.

CONCLUSIONS

Compared to the control arm, monoclonal antibody therapy showed a significantly better outcome in restraining the HR for relapse among patients with NMOSD but insignificant effects in NMOSD patients with seronegative APQ4-IgG. The safety profile in each arm had no significant difference.

Patient-reported burden of symptoms in neuromyelitis optica: A secondary analysis on pain and quality of life

INTRODUCTION

Relapses of neuromyelitis optica spectrum disorder (NMOSD) result in cumulative neurologic disabilities, are unpredictable, and are interspersed with remissions. Pain in NMOSD is often severe and intractable, with a significant impact on patient quality of life (QoL). We performed a more detailed analysis of previously published survey data on the association of pain and QoL, comparing patients who were seropositive and seronegative for antibodies against aquaporin-4 (AQP4-IgG).

METHODS

We conducted a secondary analysis of questionnaire data from 193 NMOSD patients across North America. The study population was predominantly female (88.6%) and aged 19-76 years. Results were reported for three groups: AQP4-IgG-seropositive (61.1%), AQP4-IgG-seronegative and the total cohort including patients with unknown serostatus. We measured the strength of associations and interactions between pain and variables including QoL, patient satisfaction, frequency of hospital visits, and number of relapses versus other symptoms.

RESULTS

Pain severity was the strongest negative predictor of QoL. In the total and AQP4-IgG-seropositive groups, pain was the most common symptom that patients wanted their physician to be concerned about; in the AQP4-IgG-seronegative group, this was fatigue. For all patients, frequent hospital visits and relapses were associated with more severe pain, but not frequency of NMOSD specialist visits. Patients without recent relapse still commonly reported moderate or severe pain (>25%).

CONCLUSION

This study confirms the heavy burden of pain on NMOSD patients and its effect on QoL and healthcare utilization. Prevention or early treatment of relapses and more effective pain management may reduce this burden.

The occurrence of myelin oligodendrocyte glycoprotein antibodies in aquaporin-4-antibody seronegative Neuromyelitis Optica Spectrum Disorder: A systematic review and meta-analysis

BACKGROUND

Despite inclusion in neuromyelitis optica spectrum disorders (NMOSD), myelin oligodendrocyte glycoprotein antibody (MOG-Ab)-associated diseases are increasingly recognized as an independent disease entity. In this study, we conducted a systematic review and meta-analysis to comprehensively update the rate of occurrence of MOG-Ab in Aquaporin4 (AQP4)-antibody seronegative NMOSD.

METHODS

We searched PubMed, EMBASE, and Cochrane databases for studies reporting the rates of patients with MOG-Ab in NMOSD. Fixed or random-effects models were used to pool results across studies.

RESULTS

Fourteen studies met the inclusion criteria. Overall, MOG-Abs positive patients comprised 9.3% of all NMO/NMOSD (95% confidence interval [CI] 7.9%-10.8%, I² = 13.1%), 32.5% of all AQP4-Ab seronegative NMO/NMOSD (95% CI 25.7%-39.3%, I² = 45.8%), and 41.6% of AQP4-Ab seronegative NMOSD cases diagnosed by IPND 2015 criteria (95% CI 35.1%-48.2%, I² = 0.0%). The pooled prevalence of MOG-Ab was 31.0% among Asian AQP4-Ab seronegative NMO/NMOSD patients (95% CI 22.1%-39.9% I²=54.1%) and 34.3% in European seronegative NMO/NMOSD (95% CI 21.9%-46.7%, I² = 51.9%).

CONCLUSIONS

This study shows that MOG-Abs represent a substantial proportion of AQP4-Ab seronegative NMOSD patients despite different underlying mechanisms, clinical manifestations, and treatment response, suggesting MOG-Ab screening in AQP4-Ab seronegative NMOSD patients can facilitate accurate diagnoses and treatments.

PLEX: the best first-line treatment in nmosd attacks experience at a single center in Colombia

Objective

Primary outcome was to evaluate complete improvement at six months after acute treatment in NMOSD relapses.

Methods

Retrospective observational cohort study of patients with diagnosis of NMOSD admitted for acute attacks. We performed an explanatory analysis using the univariate, bivariate and multivariate logistic regression approach. We compared survival curves using the Kaplan Meier analysis and estimated the median time for the main outcome.

Results

In the univariate analysis, basal EDSS score, AQP4-IgG positivity, PLEX as a first-line treatment (IVMP + PLEX), less systemic complications related to acute treatment and total attack history were independently associated with complete improvement at six months. After adjusting for confounding variables and using multivariate analysis by Cox Regression, positive AQ4-IgG (HR 0.04, 95% CI: 0.02–0.66) and IVMP + PLEX (HR 5.1, 95% CI: 3.9–66.4), were kept as independent factors associated to time to complete improvement. Time from admission to PLEX initiation and complete improvement at six months had a median of seven days (95% CI: 5.2–8.8). In secondary effects, there were no statistical differences between the groups.

Conclusions

PLEX + IVMP is the treatment of choice for NMOSD relapses and should be initiated as early as possible.

AQP4-IgG autoimmunity in Japan and Germany: Differences in clinical profiles and prognosis in seropositive neuromyelitis optica spectrum disorders

BACKGROUND

Clinical outcomes in neuromyelitis optica spectrum disorders (NMOSD) vary across different regions.

OBJECTIVE

To describe clinical profiles in Japanese and German NMOSD patients.

METHODS

Medical records of aquaporin-4-immunoglobulin G (AQP4-IgG) positive NMOSD patients from Japan (n = 54) and Germany (n = 38) were retrospectively analyzed.

RESULTS

The disability status was similar between both cohorts, although Japanese patients had a longer disease duration (13.3 ± 11.1 vs. 8.1 ± 6.9 years, p = 0.018) but similar relapse rates. Optic neuritis and myelitis were the most frequent attacks in both cohorts. Brain attacks occurred more frequently in Japanese patients (40.7% vs. 15.8%, p = 0.020). The time from disease onset (median [interquartile range] 2.3 [0.3-10.1] vs. 0.6 [0.2-1.9] years, p = 0.009) and the number of attacks (2.5 [1-7] vs. 2 [1-3], p = 0.047) until start of the first immunotherapy were higher in the Japanese cohort. Rituximab was the most common drug in the German cohort (52.6%) and not given in the Japanese cohort (p < 0.001), where oral prednisolone was the most common drug (92.6% vs. 15.8%, p < 0.001). The frequency of autoimmune comorbidities was higher in the German cohort (39.5% vs. 18.5%, p = 0.047).

CONCLUSION

Compared with Japanese NMOSD patients, German patients presented with similar disability despite shorter disease duration and earlier and more frequent immunosuppressive therapy.

[From neuromyelitis optica to neuromyelitis optica spectrum disorder: from clinical syndrome to diagnistic classification]

Neuromyelitis optica spectrum disorder (NMOSD), derived from NMO or Devic's disease, is considered as a distinct disease since the discovery of a novel and pathogenic serum autoantibody targeting aquaporin‑4 (AQP4-IgG) and is distinguished from classical multiple sclerosis (MS). With the continuous extension of knowledge on the clinical manifestations, the previously narrow diagnostic term NMO became NMOSD, which has also been used in the diagnostic criteria since 2015. The current diagnostic criteria enable the early diagnosis of NMOSD in patients with and without AQP4-IgG. Typical clinical manifestations include involvement of the spinal cord, optic nerve and brainstem. Typically patients with the disease also present with neuropathic pain, painful tonic spasms and also other unusual manifestations in NMOSD. Especially in AQP4-IgG positive NMOSD patients, the coexistence with other autoimmune diseases is frequently observed. In most cases NMOSD follows a relapsing course with exacerbation-free periods sometimes lasting years and can be manifested first in advanced adulthood. A subset of AQP4-IgG negative NMOSD patients have been found to harbor autoantibodies targeting myelin oligodendrocyte glycoprotein (MOG), which is considered as a distinct disease entity: these MOG antibody-associated disorders (MOGAD) can present with clinical syndromes resembling both NMOSD and MS and are currently the subject of intensive research.

Soluble IL-7Rα/sCD127 in Health, Disease, and Its Potential Role as a Therapeutic Agent

Soluble cytokine receptors can influence immune responses by modulating the biological functions of their respective ligands. These effects can be either agonistic or antagonistic and a number of soluble cytokine receptors have been shown to play critical roles in both maintenance of health and disease pathogenesis. Soluble IL-7Ra (sCD127) is one such example. With its impact on the IL-7/CD127 pathway, which is fundamental for the development and homeostasis of T cells, the role of sCD127 in health and disease has been extensively studied in recent years. Within this review, the role of sCD127 in maintaining host immune function is presented. Next, by addressing genetic factors affecting sCD127 expression and the associated levels of sCD127 production, the roles of sCD127 in autoimmune disease, infections and cancer are described. Finally, advances in the field of soluble cytokine therapy and the potential for sCD127 as a biomarker and therapeutic agent are discussed.

Eculizumab in Asian patients with anti-aquaporin-IgG-positive neuromyelitis optica spectrum disorder: A subgroup analysis from the randomized phase 3 PREVENT trial and its open-label extension

Background Eculizumab, a terminal complement inhibitor, significantly reduced the risk of relapse compared with placebo in patients with anti-aquaporin-4 immunoglobulin G-positive (AQP4+) neuromyelitis optica spectrum disorder (NMOSD) in the PREVENT trial. We report efficacy and safety analyses in Asian patients in PREVENT and its open-label extension (OLE). Methods PREVENT was a double-blind, randomized, phase 3 trial. Patients with AQP4+ NMOSD were randomly assigned (2:1) to receive intravenous eculizumab (maintenance dose, 1200 mg/2 weeks) or placebo. Patients who completed PREVENT could receive eculizumab in an OLE. Analyses were performed in a prespecified subgroup of Asian patients. Results Of 143 patients enrolled, 52 (36.4%) were included in the Asian subgroup (eculizumab, n = 37; placebo, n = 15); 45 Asian patients received eculizumab in the OLE. Most Asian patients (86.5%) received concomitant immunosuppressive therapy. During PREVENT, one adjudicated relapse occurred in patients receiving eculizumab and six occurred in patients receiving placebo in the Asian subgroup (hazard ratio, 0.05; 95% confidence interval: 0.01-0.35; p = 0.0002). An estimated 95.2% of Asian patients remained relapse-free after 144 weeks of eculizumab treatment. Upper respiratory tract infections, headache, and nasopharyngitis were the most common adverse events with eculizumab in the Asian subgroup. Conclusion Eculizumab reduces the risk of relapse in Asian patients with AQP4+ NMOSD, with a benefit-risk profile similar to the overall PREVENT population. The benefits of eculizumab were maintained during long-term therapy. Clinical trial registration ClinicalTrials.gov identifiers: NCT01892345 (PREVENT); NCT02003144 (open-label extension).

The long-term outcome of MOGAD: An observational national cohort study of 61 patients

BACKGROUND AND OBJECTIVE

The prognosis in myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is a matter of debate. Our aim was to assess the long-term outcomes of patients with MOGAD.

METHODS

We retrospectively analysed the clinical and paraclinical data of patients from the French nationwide observatory study NOMADMUS who tested positive for MOG antibodies (MOG-IgG) and who had clinical follow-up of at least 8 years from their first episode.

RESULTS

Sixty-one patients (median [range] age at onset 27 [3-69] years), with a median (mean; range) follow-up of 177 (212.8; 98-657) months, were included. Among 58 patients with a relapsing course, 26.3% relapsed in the first year after onset. Of the 61 patients, 90.2% experienced at least one episode of optic neuritis. At last visit, the median (mean; range) Expanded Disability Status Scale (EDSS) score was 1 (2.12; 0-7.5), 12.5% had an EDSS score ≥6 and 37.5% had an EDSS score ≥3. Of 51 patients with final visual acuity (VA) data available, 15.7% had VA ≤0.1 in at least one eye and 25.5% had VA ≤0.5 in at least one eye. Bilateral blindness (VA ≤0.1) was present in 5.9% of patients. Finally, 12.5% of patients presented bladder dysfunction requiring long-term urinary catheterization. No factor associated significantly with a final EDSS score ≥3 or with final VA ≤0.1 was found.

CONCLUSION

Overall long-term favourable outcomes were achieved in a majority of our patients, but severe impairment, in particular visual damage, was not uncommon.

Sensitivity analysis of the primary endpoint from the N-MOmentum study of inebilizumab in NMOSD

Background:

In the N-MOmentum trial, the risk of an adjudicated neuromyelitis optica spectrum disorder (NMOSD) attack was significantly reduced with inebilizumab compared with placebo.

Objective:

To demonstrate the robustness of this finding, using pre-specified sensitivity and subgroup analyses.

Methods:

N-MOmentum is a prospective, randomized, placebo-controlled, double-masked trial of inebilizumab, an anti-CD19 monoclonal B-cell-depleting antibody, in patients with NMOSD. Pre-planned and post hoc analyses were performed to evaluate the primary endpoint across a range of attack definitions and demographic groups, as well as key secondary endpoints.

Results:

In the N-MOmentum trial (ClinicalTrials.gov: NCT02200770), 174 participants received inebilizumab and 56 received placebo. Attack risk for inebilizumab versus placebo was consistently and significantly reduced, regardless of attack definition, type of attack, baseline disability, ethnicity, treatment history, or disease course (all with hazard ratios < 0.4 favoring inebilizumab, p < 0.05). Analyses of secondary endpoints showed similar trends.

Conclusion:

N-MOmentum demonstrated that inebilizumab provides a robust reduction in the risk of NMOSD attacks regardless of attack evaluation method, attack type, patient demographics, or previous therapy.

The N-MOmentum study is registered at ClinicalTrials.gov: NCT2200770.

Anti-IL-6 Therapies for Neuromyelitis Optica Spectrum Disorders: A Systematic Review of Safety and Efficacy

BACKGROUND

Neuromyelitis Optica Spectrum Disorder (NMOSD) is a chronic autoimmune disease of the central nervous system that causes recurrent attacks of optic neuritis, myelitis, and brainstem symptoms, resulting in severe neurological disability. Preventive treatment with immunosuppressive agents reduces relapse rate and improves long-term prognosis. In recent years, the potential therapeutical effect of new agents has been investigated. Two of these, the anti-interleukin 6 (IL-6) agents tocilizumab and satralizumab, have been studied in active NMOSD.

OBJECTIVE

To systematically review the current data regarding the efficacy and safety of anti-IL-6 agents in NMOSD.

RESULTS

Fourteen case reports and 5 case series of intravenous tocilizumab have shown beneficial clinical and paraclinical effects compared to commonly used therapies, and another case series of subcutaneous tocilizumab has shown it is as effective as the IV formulation. A phase 2 comparative trial has shown tocilizumab IV to be more effective than azathioprine for relapse prevention. A phase 3 trial of subcutaneous satralizumab versus placebo, has shown a lower risk of relapse in the sartralizumab-treated group, both as add-on therapy to stable immunosuppressant and as monotherapy. Tocilizumab also reduced pain severity in two trials and fatigue scores in one trial, but satralizumab did not significantly improve pain and fatigue. Adverse events with both agents were relatively mild and comparable to placebo and azathioprine.

CONCLUSION

The anti-Il-6 agents tocilizumab and satralizumab show promising results in active NMOSD. Further randomized, larger-scale trials are needed to better define the role of these agents in the growing arsenal of NMOSD treatments.

AQP4-IgG and MOG-IgG Related Optic Neuritis-Prevalence, Optical Coherence Tomography Findings, and Visual Outcomes: A Systematic Review and Meta-Analysis

Background: Optic neuritis (ON) is a cardinal manifestation of multiple sclerosis (MS), aquaporin-4 (AQP4)-IgG-, and myelin oligodendrocyte glycoprotein (MOG)-IgG-associated disease. However, the prevalence of AQP4-IgG seropositivity and MOG-IgG seropositivity in isolated ON is unclear, and studies comparing visual outcomes and optical coherence tomography (OCT)-derived structural retinal measures between MS-ON, AQP4-ON, and MOG-ON eyes are limited by small sample sizes. Objectives: (1) To assess the prevalence of AQP4-IgG and MOG-IgG seropositivity among patients presenting with isolated ON; (2) to compare visual outcomes and OCT measures between AQP4-ON, MOG-ON, and MS-ON eyes. Methods: In this systematic review and meta-analysis, a total of 65 eligible studies were identified by PubMed search. Statistical analyses were performed with random effects models. Results: In adults with isolated ON, AQP4-IgG seroprevalence was 4% in non-Asian and 27% in Asian populations, whereas MOG-IgG seroprevalence was 8 and 20%, respectively. In children, AQP4-IgG seroprevalence was 0.4% in non-Asian and 15% in Asian populations, whereas MOG-IgG seroprevalence was 47 and 31%, respectively. AQP4-ON eyes had lower peri-papillary retinal nerve fiber layer (pRNFL; -11.7 μm, 95% CI: -15.2 to -8.3 μm) and macular ganglion cell + inner plexiform layer (GCIPL; -9.0 μm, 95% CI: -12.5 to -5.4 μm) thicknesses compared with MS-ON eyes. Similarly, pRNFL (-11.2 μm, 95% CI: -21.5 to -0.9 μm) and GCIPL (-6.1 μm, 95% CI: -10.8 to -1.3 μm) thicknesses were lower in MOG-ON compared to MS-ON eyes, but did not differ between AQP4-ON and MOG-ON eyes (pRNFL: -1.9 μm, 95% CI: -9.1 to 5.4 μm; GCIPL: -2.6 μm, 95% CI: -8.9 to 3.8 μm). Visual outcomes were worse in AQP4-ON compared to both MOG-ON (mean logMAR difference: 0.60, 95% CI: 0.39 to 0.81) and MS-ON eyes (mean logMAR difference: 0.68, 95% CI: 0.40 to 0.96) but were similar in MOG-ON and MS-ON eyes (mean logMAR difference: 0.04, 95% CI: -0.05 to 0.14). Conclusions: AQP4-IgG- and MOG-IgG-associated disease are important diagnostic considerations in adults presenting with isolated ON, especially in Asian populations. Furthermore, MOG-IgG seroprevalence is especially high in pediatric isolated ON, in both non-Asian and Asian populations. Despite a similar severity of GCIPL and pRNFL thinning in AQP4-ON and MOG-ON, AQP4-ON is associated with markedly worse visual outcomes.

Differences in Advanced Magnetic Resonance Imaging in MOG-IgG and AQP4-IgG Seropositive Neuromyelitis Optica Spectrum Disorders: A Comparative Study

Aims: To explore differences in advanced brain magnetic resonance imaging (MRI) characteristics between myelin oligodendrocyte (MOG) immunoglobulin (IgG) and aquaporin-4 (AQP4) IgG seropositive (+) neuromyelitis optica spectrum disorders (NMOSD).

Methods: 33 AQP4-IgG and 18 MOG-IgG seropositive NMOSD patients and 61 healthy control (HC) subjects were included. All 112 participants were scanned with the same standardized MRI-protocol on a 3-Tesla MRI-scanner. Brain volume and diffusion tensor imaging (DTI) parameters were assessed.

Results: MOG-IgG+ patients showed reduced parallel diffusivity within white matter tracts compared to HC whereas AQP4-IgG+ showed no significant brain parenchymal damage in DTI analysis. AQP4-IgG+ patients showed reduced whole brain volumes and reduced volumes of several deep gray matter structures compared to HC whereas MOG-IgG+ patients did not show reduced brain or deep gray matter volumes compared to HC.

Conclusions: Microstructural brain parenchymal damage in MOG-IgG+ patients was more pronounced than in AQP4-IgG+ patients, compared with HC, whereas normalized brain volume reduction was more severe in AQP4-IgG+ patients. Longitudinal imaging studies are warranted to further investigate this trend in NMOSD. Our results suggest that MOG-IgG+ and AQP4-IgG+ NMOSD patients differ in cerebral MRI characteristics. Advanced MRI analysis did not help to differentiate between MOG-IgG+ and AQP4-IgG+ patients in our study.

Understanding Pediatric Neuroimmune Disorder Conflicts: A Neuroradiologic Approach in the Molecular Era

Neuroimmune disorders in children are a complex group of inflammatory conditions of the central nervous system with diverse pathophysiologic mechanisms and clinical manifestations. Improvements in antibody analysis, genetics, neuroradiology, and different clinical phenotyping have expanded knowledge of the different neuroimmune disorders. The authors focus on pediatric-onset myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease, which is a new entity in the spectrum of inflammatory demyelinating diseases, distinct from both multiple sclerosis (MS) and anti-aquaporin-4 (AQP4) antibody neuromyelitis optica spectrum disorders (NMOSDs). The authors review the importance of an optimized antibody-detection assay, the frequency of MOG antibodies in children with acquired demyelinating syndrome (ADS), the disease course, the clinical spectrum, proposed diagnostic criteria, and neuroimaging of MOG antibody-associated disease. Also, they outline differential diagnosis from other neuroimmune disorders in children according to the putative primary immune mechanism. Finally, they recommend a diagnostic algorithm for the first manifestation of ADS or relapsing ADS that leads to four demyelinating syndromes: MOG antibody-associated disease, AQP4 antibody NMOSDs, MS, and seronegative relapsing ADS. This diagnostic approach provides a framework for the strategic role of neuroradiology in diagnosis of ADS and decision making, to optimize patient care and treatment outcome in concert with clinicians. Online supplemental material is available for this article. ^©RSNA, 2020.

Emerging drugs for the treatment of neuromyelitis optica

INTRODUCTION

Evidence-based treatment options for neuromyelitis optica spectrum disorders (NMOSD) patients are beginning to enter the market. Where previously, there was only the exclusive use of empiric and off-label immunosuppressants in this rare and devastating central nervous system autoimmune disease.

AREAS COVERED

In accordance to expanding pathogenetic insights, drugs in phase II and III clinical trials are presented in the context of the current treatment situation for acute attacks and immunopreventative strategies in NMOSD. Some such drugs are the 2019-approved complement inhibitor eculizumab, other compounds in late development include its modified successor ravulizumab, IL-6 receptor antibody satralizumab, CD19 targeting antibody inebilizumab and the TACI-Fc fusion protein telitacicept.

EXPERT OPINION

Moving from broad immunosuppression to tailored treatment strategies, the prospects for efficient NMOSD therapy are positive. For the first time in this disease, class I treatment evidence is available, but long-term data will be necessary to confirm the overall promising study results of the compounds close to approval. While drug development still centers around AQP4 antibody seropositive patients, current and future research requires consideration of possible diverging treatment demands for the smaller group of seronegative patients and patients with presence of MOG antibodies.