Temporal Dynamics of MOG Antibodies in Children With Acquired Demyelinating Syndrome

A Simple Score (MOG-AR) to Identify Individuals at High Risk of Relapse After MOGAD Attack

BACKGROUND AND OBJECTIVES

To identify predictors for relapse in patients with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) and to develop and validate a simple risk score for predicting relapse.

METHODS

In China National Registry of Neuro-Inflammatory Diseases (CNRID), we identified patients with MOGAD from March 2023 and followed up prospectively to September 2023. The primary endpoint was MOGAD relapse, confirmed by an independent panel. Patients were randomly divided into model development (75%) and internal validation (25%) cohorts. Prediction models were constructed and internally validated using Andersen-Gill models. Nomogram and relapse risk score were generated based on the final prediction models.

RESULTS

A total of 188 patients (comprising 612 treatment episodes) were included in cohorts. Female (HR: 0.687, 95% CI 0.524-0.899, p = 0.006), onset age 45 years or older (HR: 1.621, 95% CI 1.242-2.116, p < 0.001), immunosuppressive therapy (HR: 0.338, 95% CI 0.239-0.479, p < 0.001), oral corticosteroids >3 months (HR 0.449, 95% CI 0.326-0.620, p < 0.001), and onset phenotype (p < 0.001) were identified as factors associated with MOGAD relapse. A predictive score, termed MOG-AR (Immunosuppressive therapy, oral Corticosteroids, Onset Age, Sex, Attack phenotype), derived in prediction model, demonstrated strong predictive ability for MOGAD relapse. MOG-AR score of 13-16 indicates a higher risk of relapse (HR: 3.285, 95% CI 1.473-7.327, p = 0.004).

DISCUSSION

The risk of MOGAD relapse seems to be predictable. Further validation of MOG-AR score developed from this cohort to determine appropriate treatment and monitoring frequency is warranted.

TRIAL REGISTRATION INFORMATION

CNRID, NCT05154370, registered December 13, 2021, first enrolled December 15, 2021.

Clinical practice guidelines for multiple sclerosis, neuromyelitis optica spectrum disorder, and myelin oligodendrocyte glycoprotein antibody-associated disease 2023 in Japan

BACKGROUND

The previous Japanese clinical practice guidelines for multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) were published in 2017. Recently, for the first time in 6 years, the MS and NMOSD guideline development committee revised the Japanese guidelines for MS, NMOSD, and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD).

METHODS

The committee utilized the Grading of Recommendations Assessment, Development, and Evaluation system based on the "Minds Handbook for Clinical Practice Guideline Development 2020 Ver. 3.0″ with a focus on clinical questions (CQs). The committee also discussed clinical issues other than CQs, categorizing them as a question-and-answer (Q&A) section, including "issues on which experts' opinions agree to a certain extent" and "issues that are important but not included in the CQ".

RESULTS

The committee identified 3, 1, and 1 key CQs related to MS, NMOSD, and MOGAD, respectively, and presented recommendations. A Q&A session regarding disease-modifying therapies and relapse prevention therapies for MS, NMOSD, and MOGAD was conducted. The revised guidelines were published in September 2023.

CONCLUSIONS

The Japanese guidelines for clinical practice on MS, NMOSD, and MOGAD were updated. Treatment strategies for MS, NMOSD, and MOGAD are changing, and these updated guidelines may assist with treatment decisions for these diseases in clinical practice.

Time to Treat First Acute Attack of Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease

Importance

A proportion of people with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) have a relapsing disease course and persistent anti-myelin oligodendrocyte glycoprotein immunoglobulin G (MOG-IgG) seropositivity. Few studies have investigated whether treatment of the first MOGAD attack is associated with the long-term disease course and/or MOG-IgG seronegative conversion.

Objective

To investigate the association of time to treat the first acute MOGAD attack with relapse risk and MOG-IgG serostatus.

Design, Setting, and Participants

This was a retrospective, nationwide, multicenter cohort study involving 14 secondary or tertiary hospitals in South Korea between November 2009 and August 2023. People with adult-onset MOGAD, who either had a relapse or were followed up for more than 12 months after disease onset and had a detailed medical record of their first attack, were included. Individuals were excluded for adolescent-onset MOGAD or short disease duration.

Exposures

Patients were categorized based on the time to treat the first acute MOGAD attack: early (<5 days), intermediate (5-14 days), and late (not treated within 14 days).

Main Outcomes and Measures

A multivariable analysis for clinical and treatment factors associated with relapsing disease course and/or MOG-IgG seronegative conversion. Further subgroup analyses were conducted among those without long-term nonsteroidal immunosuppressant (NSIS) maintenance treatment.

Results

Among the 315 individuals screened, 75 were excluded. A total of 240 patients (median [IQR] age at onset, 40.4 [28.8-56.1] years; 125 female [52.1%]) with median (IQR) disease duration of 3.07 (1.95-6.15) years were included. A total of 110 of 240 patients (45.8%) relapsed after a median (IQR) of 0.45 (0.18-1.68) years, and 29 of 116 patients (25.0%) experienced a conversion to seronegative MOG-IgG. Both the time to treatment of the first MOGAD attack (late vs early: adjusted hazard ratio [aHR], 2.64; 95% CI, 1.43-4.84; P = .002; intermediate vs early: aHR, 2.02; 95% CI, 1.10-3.74; P = .02) and NSIS maintenance treatment (aHR, 0.24; 95% CI, 0.14-0.42; P < .001) were independently associated with the risk of relapse. In a subgroup without NSIS maintenance, the time to treat of the first MOGAD attack was still associated with higher risk of relapse (late vs early: aHR, 3.51; 95% CI, 1.64-7.50; P = .001; intermediate vs early: aHR, 2.68; 95% CI, 1.23-5.85; P = .01). Lastly, the time to treat of the first MOGAD attack was also associated with MOG-IgG seronegative conversion (early vs late: adjusted odds ratio, 7.04; 95% CI, 1.58-31.41; P = .01), whereas NSIS maintenance treatment was not.

Conclusions and Relevance

Results of this cohort study suggest that early treatment of the first acute MOGAD attack was associated with a reduction in the proportion of relapsing disease course and an increase in the likelihood of MOG-IgG seronegative conversion. These data suggest that timing of acute phase treatment for the first MOGAD attack can be associated with the long-term prognosis and autoimmune status of patients.

MOG antibody-associated optic neuritis

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is a demyelinating disorder, distinct from multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD). MOGAD most frequently presents with optic neuritis (MOG-ON), often with characteristic clinical and radiological features. Bilateral involvement, disc swelling clinically and radiologically, and longitudinally extensive optic nerve hyperintensity with associated optic perineuritis on MRI are key characteristics that can help distinguish MOG-ON from optic neuritis due to other aetiologies. The detection of serum MOG immunoglobulin G utilising a live cell-based assay in a patient with a compatible clinical phenotype is highly specific for the diagnosis of MOGAD. This review will highlight the key clinical and radiological features which expedite diagnosis, as well as ancillary investigations such as visual fields, visual evoked potentials and cerebrospinal fluid analysis, which may be less discriminatory. Optical coherence tomography can identify optic nerve swelling acutely, and atrophy chronically, and may transpire to have utility as a diagnostic and prognostic biomarker. MOG-ON appears to be largely responsive to corticosteroids, which are often the mainstay of acute management. However, relapses are common in patients in whom follow-up is prolonged, often in the context of early or rapid corticosteroid tapering. Establishing optimal acute therapy, the role of maintenance steroid-sparing immunotherapy for long-term relapse prevention, and identifying predictors of relapsing disease remain key research priorities in MOG-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.

Pediatric Autoimmune Neurologic Disorders

OBJECTIVE

This article discusses common principles in diagnosing and managing autoimmune neurologic conditions in children.

LATEST DEVELOPMENTS

The key to improving outcomes in all patients with autoimmune neurologic diseases is making an early diagnosis, promptly initiating treatment, and identifying patients who will benefit from long-term maintenance treatment. Some neuroinflammatory syndromes can be diagnosed with an antibody biomarker (eg, aquaporin-4 antibodies, N-methyl-d-aspartate [NMDA] receptor antibodies), whereas others require clinical diagnostic criteria (eg, multiple sclerosis, opsoclonus-myoclonus syndrome). A proportion of children will be labeled as seronegative, and further investigations for other inflammatory or monogenetic etiologies need to be carried out in parallel with treating the central nervous system inflammation. Time to treatment and treatment escalation were shown to correlate with outcomes in many patients with these disorders. The choice and duration of treatment should be evaluated considering side effects and risks in the short and long terms. The presence of a highly inflammatory disease process in children supports the use of highly effective disease-modifying therapies in pediatrics.

ESSENTIAL POINTS

The phenotypes of pediatric autoimmune neurologic conditions may change across different age groups, as the brain is still actively developing. In general, the presentation in children is more inflammatory, but overall disability is lower, likely because of better neuroplasticity and repair. Convincing evidence has increasingly emerged to support the biological rationale that effective immunosuppressive therapies used in adult neuroimmunology are equally effective in children.

Frequency, characteristics, predictors and treatment of relapsing myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD)

BACKGROUND

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) may have a monophasic or relapsing disease course. To date, factors that may predict a relapsing disease course remain largely unknown and only limited data exist regarding the efficacy of different utilized immunotherapy regimens at preventing or reducing relapses.

OBJECTIVES

To assess the characteristics, predictors, and immunotherapy of relapsing MOGAD.

METHODS

This multicenter retrospective analysis included all MOGAD cases at the University of Florida, Baylor College of Medicine and the University of California San Diego with minimum follow-up time of 6 months. Cox proportional hazards regression analyses, corrected for age and sex, were performed to evaluate hazard ratios (HR) of predictors of a relapsing disease course and to compare relapse hazards for utilized immunotherapies.

RESULTS

The majority of included participants (51/79 [64.6 %]) had a relapsing course, and of these individuals, 68.6 % (35/51) experienced their first relapse within the first year. However, 10/51 (19.6 %) participants experienced their first relapse ≥5 years (5-15 years) after the initial presentation. Predictors of a relapsing course were CSF pleocytosis (>150 cells/mm3; HR 3.3 [1.18 - 9.24]; p = 0.023), a pediatric disease onset at age < 9 years (HR 2.69 [1.07-6.75]; p = 0.035), and an initial presentation with the clinical syndrome of meningoencephalitis (HR 3.42 [1.28 - 9.17]; p = 0.015),. In participants with a relapsing course, 13/24 (54.2 %) patients remained relapse-free on rituximab, 4/8 (50 %) on mycophenolate mofetil, and 11/14 (78.6 %) on scheduled immunoglobulins. Patients treated with immunoglobulins had significantly fewer relapses compared to patients treated with other immunotherapies (HR: 0.1 [0.2 - 0.63]; p = 0.014).

CONCLUSIONS

In our cohort, the majority of MOGAD patients relapsed. The initial relapse occurred most frequently within the first year, but first relapses also took place over a decade after the initial presentation. Prepubertal onset, severe CSF pleocytosis, and the clinical syndrome of meningoencephalitis may be predictors of a relapsing course. Of the currently available off-label steroid-sparing treatments, scheduled immunoglobulins may be the most effective in relapse prevention.

Brazilian consensus recommendations on the diagnosis and treatment of autoimmune encephalitis in the adult and pediatric populations

BACKGROUND

 Autoimmune encephalitis (AIE) is a group of inflammatory diseases characterized by the presence of antibodies against neuronal and glial antigens, leading to subacute psychiatric symptoms, memory complaints, and movement disorders. The patients are predominantly young, and delays in treatment are associated with worse prognosis.

OBJECTIVE

 With the support of the Brazilian Academy of Neurology (Academia Brasileira de Neurologia, ABN) and the Brazilian Society of Child Neurology (Sociedade Brasileira de Neurologia Infantil, SBNI), a consensus on the diagnosis and treatment of AIE in Brazil was developed using the Delphi method.

METHODS

 A total of 25 panelists, including adult and child neurologists, participated in the study.

RESULTS

 The panelists agreed that patients fulfilling criteria for possible AIE should be screened for antineuronal antibodies in the serum and cerebrospinal fluid (CSF) using the tissue-based assay (TBA) and cell-based assay (CBA) techniques. Children should also be screened for anti-myelin oligodendrocyte glucoprotein antibodies (anti-MOG). Treatment should be started within the first 4 weeks of symptoms. The first-line option is methylprednisolone plus intravenous immunoglobulin (IVIG) or plasmapheresis, the second-line includes rituximab and/or cyclophosphamide, while third-line treatment options are bortezomib and tocilizumab. Most seizures in AIE are symptomatic, and antiseizure medications may be weaned after the acute stage. In anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis, the panelists have agreed that oral immunosuppressant agents should not be used. Patients should be evaluated at the acute and postacute stages using functional and cognitive scales, such as the Mini-Mental State Examination (MMSE), the Montreal Cognitive Assessment (MoCA), the Modified Rankin Scale (mRS), and the Clinical Assessment Scale in Autoimmune Encephalitis (CASE).

CONCLUSION

 The present study provides tangible evidence for the effective management of AIE patients within the Brazilian healthcare system.

Myelin Oligodendrocyte Glycoprotein-Antibody Associated Disease: An Updated Review of the Clinical Spectrum, Pathogenetic Mechanisms and Therapeutic Management

Clinical syndromes associated with antibodies against myelin oligodendrocyte glycoprotein (MOG) are now recognized as a distinct neurological disease entity, and are gaining increasing attention. The pathogenic mechanisms underlying MOG-antibody disease (MOGAD) remain incompletely understood. Case series, facilitated by registries, and observational studies over the past few years have shed increasing light on the clinical aspects and therapeutic approaches of MOGAD. MOGAD may manifest with a variety of clinical syndromes, including acute disseminated encephalomyelitis (ADEM), autoimmune encephalitis, optic neuritis (ON) and transverse myelitis (TM). MOGAD can be either monophasic or relapsing. This review aims to provide a comprehensive updated description of the clinical spectrum, paraclinical features, and prognosis of MOG-antibody disease, as well as summarize its therapeutic considerations. Randomized clinical trials, standardized diagnostic criteria and treatment guidelines are the steps forward.

Clinical analysis of myelin oligodendrocyte glycoprotein antibody-associated disease in a diverse cohort of children: A single-center observational study

BACKGROUND

Prognostic markers for relapse and neurological disability following the first clinical event in children with myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) remain lacking. We investigated the clinical profiles and early prognostic factors associated with relapsing disease or impaired functional outcome in a large single-center cohort of pediatric MOGAD.

METHODS

We retrospectively analyzed the clinical and paraclinical data and treatment outcomes of children with MOGAD seen at Children's Health in Dallas, Texas from 2009 to 2022. Univariate analyses were used to evaluate factors from initial event associated with relapsing disease course and impaired functional outcome (modified Rankin scale [mRS] >1) at final follow-up.

RESULTS

Our cohort comprised of 87 children of diverse race/ethnicity. Presentation with acute disseminated encephalomyelitis (ADEM) was more frequent in children aged ≤8 years and Caucasian background, whereas presentation with optic neuritis was more common in children aged >8 years and other race/ethnicity. 44.3 % (27/61) had relapsing disease course, of whom 48.0 % had multiple relapses. 30.3 % (23/76) had final mRS >1. Children with abnormal electroencephalogram had reduced relapse risk. Children with ADEM presentation, severe disease, low MOG-IgG titer, and central and systemic inflammation (represented by cerebrospinal fluid pleocytosis and serum leukocytosis, respectively) at onset had higher likelihood of final mRS >1.

CONCLUSION

Abnormal electroencephalogram at the first event was associated with reduced relapse risk while disease severity and peripheral inflammation significantly contributed to final neurological disability. Further studies are needed to validate these findings as early risk factors for disability and relapse and to identify optimal treatment strategies.

Predictive value of persistent antibodies at 6 months for relapse in neuronal surface antibody-associated autoimmune encephalitis

BACKGROUND

For patients with neuronal surface antibody-associated autoimmune encephalitis (NSAE) whose clinical symptoms gradually improve, the recommended course of immunotherapy in China is about 6 months. We aim to explore the relationship between persistent antibody positivity when immunotherapy is discontinued at 6 months and subsequent relapse.

METHODS

Prospective inclusion of NSAE patients with clinical remission after 6-month immunotherapy. Their antibody titers and other clinical data were collected at onset and 6 months later. Based on the antibody test results at 6 months, patients were divided into an antibody-persistent group and an antibody-negative conversion group, and then the rate of relapse between the two groups were compared.

RESULTS

The study included 28 NSAE patients who were antibody-positive at diagnosis. After 6-month immunotherapy, there were 16 (57.1%) cases with persistent antibodies and 12 (42.9%) cases with antibody-negative conversion. In the acute phase of onset, seizures were more common in patients with persistent antibodies (87.5% vs. 50.0%, p = 0.044). During a mean follow-up period of 22 months, patients with persistent antibodies were more likely to experience relapse than those with antibody-negative conversion (37.5% vs. 0.0%, p = 0.024). There were no significant differences in antibody types, CSF findings, results of MRI and EEG, tumor combination, immunotherapy, and long-term outcome between the two groups (p > 0.05).

CONCLUSIONS

For patients with persistent antibodies when immunotherapy is discontinued at 6 months, persistent antibody positivity was associated with a higher relapse rate.

Is there an immunological cross-reactivity of antibodies to the myelin oligodendrocyte glycoprotein and coronaviruses?

Recent reports indicated that myelin oligodendrocyte glycoprotein antibody-associated disease might be a rare complication after severe acute respiratory syndrome coronavirus 2 infection or vaccination. It is unclear whether this is an unspecific sequel of infection or vaccination or caused by possible immunological cross-reactivity of severe acute respiratory syndrome coronavirus 2 proteins and myelin oligodendrocyte glycoprotein. The aim of this study was therefore to elucidate whether there is an immunological cross-reactivity between severe acute respiratory syndrome coronavirus 2 spike or nucleocapsid proteins and myelin oligodendrocyte glycoprotein and to explore the relation of antibody responses against myelin oligodendrocyte glycoprotein and severe acute respiratory syndrome coronavirus 2 and other coronaviruses. We analysed serum samples from patients with severe acute respiratory syndrome coronavirus 2 infection and neurological symptoms with (myelin oligodendrocyte glycoprotein antibody-associated disease, n = 12) or without myelin oligodendrocyte glycoprotein-antibodies (n = 10); severe acute respiratory syndrome coronavirus 2 infection without neurological symptoms (n = 32); vaccinated patients with no history of severe acute respiratory syndrome coronavirus 2 infection and neurological symptoms with (myelin oligodendrocyte glycoprotein antibody-associated disease, n = 10) or without myelin oligodendrocyte glycoprotein-antibodies (n = 9); and severe acute respiratory syndrome coronavirus 2 negative/naïve unvaccinated patients with neurological symptoms with (myelin oligodendrocyte glycoprotein antibody-associated disease, n = 47) or without myelin oligodendrocyte glycoprotein-antibodies (n = 20). All samples were analysed for serum antibody responses to myelin oligodendrocyte glycoprotein, severe acute respiratory syndrome coronavirus 2, and other common coronaviruses (CoV-229E, CoV-HKU1, CoV-NL63 and CoV-OC43). Based on sample amount and antibody titres, 21 samples were selected for analysis of antibody cross-reactivity between myelin oligodendrocyte glycoprotein and severe acute respiratory syndrome coronavirus 2 spike and nucleocapsid proteins using affinity purification and pre-absorption. Whereas we found no association of immunoglobulin G and A myelin oligodendrocyte glycoprotein antibodies with coronavirus antibodies, infections with severe acute respiratory syndrome coronavirus 2 correlated with an increased immunoglobulin M myelin oligodendrocyte glycoprotein antibody response. Purified antibodies showed no cross-reactivity between severe acute respiratory syndrome coronavirus 2 spike protein and myelin oligodendrocyte glycoprotein. However, one sample of a patient with myelin oligodendrocyte glycoprotein antibody-associated disease following severe acute respiratory syndrome coronavirus 2 infection showed a clear immunoglobulin G antibody cross-reactivity to severe acute respiratory syndrome coronavirus 2 nucleocapsid protein and myelin oligodendrocyte glycoprotein. This patient was also seropositive for other coronaviruses and showed immunological cross-reactivity of severe acute respiratory syndrome coronavirus 2 and CoV-229E nucleocapsid proteins. Overall, our results indicate that an immunoglobulin G antibody cross-reactivity between myelin oligodendrocyte glycoprotein and severe acute respiratory syndrome coronavirus 2 proteins is rare. The presence of increased myelin oligodendrocyte glycoprotein-immunoglobulin M antibodies after severe acute respiratory syndrome coronavirus 2 infection may either be a consequence of a previous infection with other coronaviruses or arise as an unspecific sequel after viral infection. Furthermore, our data indicate that myelin oligodendrocyte glycoprotein-immunoglobulin A and particularly myelin oligodendrocyte glycoprotein-immunoglobulin M antibodies are a rather unspecific sequel of viral infections. Finally, our findings do not support a causative role of coronavirus infections for the presence of myelin oligodendrocyte glycoprotein-immunoglobulin G antibodies.

Erratum: Delimiting MOGAD as a disease entity using translational imaging

[This corrects the article DOI: 10.3389/fneur.2023.1216477.].

Visual outcome measures in pediatric myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD)

BACKGROUND

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) comprises various age-dependent clinical phenotypes and may be monophasic, multiphasic, or chronic. Optic neuritis (ON) is a common manifestation and frequently appears in combination with other MOGAD phenotypes, particularly in young children. Despite permanent structural damage to the retinal nerve fiber layer (RNFL), children often experience complete visual recovery.

AIMS

To analyze the progression and impact of MOGAD on the visual system of pediatric patients independently of the history of ON.

METHODS

This retrospective study included children who met specific criteria: myelin oligodendrocyte glycoprotein (MOG) immunoglobulin G (IgG) seropositivity, acute presentation of MOGAD, and written general consent. Main outcome measures were global peripapillary retinal nerve fiber layer (pRNFL) thickness, and near and distance visual acuity, analyzed using descriptive statistics.

RESULTS

We identified 10 patients with median age of 7.7 years at first event: 7 patients manifested with acute disseminated encephalomyelitis (ADEM) (with ON 5/7, ADEM only 1/7, with transverse myelitis (TM) 1/7), 2 with isolated ON, and 1 patient with neuromyelitis optica spectrum disorder (NMOSD)-like phenotype with ON. Among ON patients, 5/8 were affected bilaterally, with 3 initially diagnosed with unilateral ON but experiencing subsequent involvement of the fellow eye. None of the patients without previous ON showed a deterioration of visual acuity and, if evaluated, a reduction of the pRNFL.

CONCLUSION

Most pediatric MOGAD-ON patients in our cohort presented with acute vison loss and optic disc edema. All patients achieved complete visual recovery, independent of number of relapses or initial visual loss. The pRNFL thickness decreased for several months and stabilized at reduced levels after 12 months in the absence of further relapses. MOGAD may not have subclinical/'silent' effects on the visual system, as visual acuity and pRNFL were not affected in patients without ON.

The pathogenesis of multiple sclerosis: a series of unfortunate events

Multiple sclerosis (MS) is characterized by the chronic inflammatory destruction of myelinated axons in the central nervous system. Several ideas have been put forward to clarify the roles of the peripheral immune system and neurodegenerative events in such destruction. Yet, none of the resulting models appears to be consistent with all the experimental evidence. They also do not answer the question of why MS is exclusively seen in humans, how Epstein-Barr virus contributes to its development but does not immediately trigger it, and why optic neuritis is such a frequent early manifestation in MS. Here we describe a scenario for the development of MS that unifies existing experimental evidence as well as answers the above questions. We propose that all manifestations of MS are caused by a series of unfortunate events that usually unfold over a longer period of time after a primary EBV infection and involve periodic weakening of the blood-brain barrier, antibody-mediated CNS disturbances, accumulation of the oligodendrocyte stress protein αB-crystallin and self-sustaining inflammatory damage.

Susceptibility-based imaging aids accurate distinction of pediatric-onset MS from myelin oligodendrocyte glycoprotein antibody-associated disease

BACKGROUND

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) and pediatric-onset multiple sclerosis (POMS) share clinical and magnetic resonance imaging (MRI) features but differ in prognosis and management. Early POMS diagnosis is essential to avoid disability accumulation. Central vein sign (CVS), paramagnetic rim lesions (PRLs), and central core lesions (CCLs) are susceptibility-based imaging (SbI)-related signs understudied in pediatric populations that may help discerning POMS from MOGAD.

METHODS

T2-FLAIR and SbI (three-dimensional echoplanar imaging (3D-EPI)/susceptibility-weighted imaging (SWI) or similar) were acquired on 1.5T/3T scanners. Two readers assessed CVS-positive rate (%CVS+), and their average score was used to build a receiver operator curve (ROC) assessing the ability to discriminate disease type. PRLs and CCLs were identified using a consensual approach.

RESULTS

The %CVS+ distinguished 26 POMS cases (mean age 13.7 years, 63% females, median EDSS 1.5) from 14 MOGAD cases (10.8 years, 35% females, EDSS 1.0) with ROC = 1, p < 0.0001, (cutoff 41%). PRLs were only detectable in POMS participants (mean 2.1±2.3, range 1-10), discriminating the two conditions with a sensitivity of 69% and a specificity of 100%. CCLs were more sensitive (81%) but less specific (71.43%).

CONCLUSION

The %CVS+ and PRLs are highly specific markers of POMS. After proper validation on larger multicenter cohorts, consideration should be given to including such imaging markers for diagnosing POMS at disease onset.

Reshaping neuroimmunology: diagnosis and treatment in the era of precision medicine

Precision medicine has revolutionized the field of neuroimmunology, with innovative approaches that characterize diseases based on their biology, deeper understanding of the factors leading to heterogeneity within the same disease, development of targeted therapies, and strategies to tailor therapies to each patient. This review explores the impact of precision medicine on various neuroimmunological conditions, including multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), optic neuritis, autoimmune encephalitis, and immune-mediated neuropathies. We discuss advances in disease subtyping, recognition of novel entities, promising biomarkers, and the development of more selective monoclonal antibodies and cutting-edge synthetic cell-based immunotherapies in neuroimmunological disorders. In addition, we analyze the challenges related to affordability and equity in the implementation of these emerging technologies, especially in situations with limited resources.

The Impact of Neuroimmunologic Disease and Developing Nervous System

Over the last two decades, neuroimmunologic disorders of childhood have been increasingly described, phenotyped, and treated. These disorders remain rare in the general population and while sharing common therapeutic interventions due to their immune pathophysiology, are heterogeneous with regard to presentation and risk of recurrence. As such, the impact of these disorders on the developing brain has come into the forefront of emerging research in pediatric neuroimmunology. Investigations into the singular impact of monophasic disease on long-term development and the impact of early and aggressive disease-modifying therapy in relapsing conditions are quickly becoming areas of ripe investigation as the field's most optimal way to treat and monitor these conditions over time. Although critically important in evaluating the developing brain, research has been heterogeneous among these diseases and limited by small cohort size. This narrative review details the role of common neuroimmunologic disorders in long-term neurological and cognitive outcomes in children as they develop.

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.

Clinical features of MOGAD with brainstem involvement in the initial attack versus NMOSD and MS

OBJECTIVE

To assess the characteristics of Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disorder (MOGAD) with brainstem involvement in the first event (BSIFE) and make comparisons with aquaporin-4-IgG seropositive neuromyelitis optica spectrum disorder (AQP4-IgG-NMOSD) and multiple sclerosis (MS).

METHODS

From 2017 to 2022, this study identified MOG-IgG-positive patients with brainstem or both brainstem and cerebellum lesions in the first episode. As a comparison group, AQP4-IgG-NMOSD (n = 30) and MS (n = 30) patients with BSIFE were enroled.

RESULTS

Thirty-five patients (35/146, 24.0%) were the BSIFE of MOGAD. Isolated brainstem episodes occurred in 9 of the 35 (25.7%) MOGAD patients, which was similar to MS (7/30, 23.3%) but was lower than AQP4-IgG-NMOSD (17/30, 56.7%, P = 0.011). Pons (21/35, 60.0%), medulla oblongata (20/35, 57.1%) and middle cerebellar peduncle (MCP, 19/35, 54.3%) were the most frequently affected areas. Intractable nausea (n = 7), vomiting (n = 8) and hiccups (n = 2) happened in MOGAD patients, but EDSS of MOGAD was lower than AQP4-IgG-NMOSD (P = 0.001) at the last follow-up. MOGAD patients with or without BSIFE did not significantly differ in terms of the ARR (P = 0.102), mRS (P = 0.823), or EDSS (P = 0.598) at the most recent follow-up. Specific oligoclonal bands appeared in MOGAD (13/33, 39.4%) and AQP4-IgG-NMOSD (7/24, 29.2%) in addition to MS (20/30, 66.7%). Fourteen MOGAD patients (40.0%) experienced relapse in this study. When the brainstem was involved in the first attack, there was an increased likelihood of a second attack occurring at the same location (OR=12.22, 95%CI 2.79 to 53.59, P = 0.001). If the first and second events were both in the brainstem, the third event was likely to occur at the same location (OR=66.00, 95%CI 3.47 to 1254.57, P = 0.005). Four patients experienced relapses after the MOG-IgG turned negative.

CONCLUSION

BSIFE occurred in 24.0% of MOGAD. Pons, medulla oblongata and MCP were the most frequently involved regions. Intractable nausea, vomiting and hiccups occurred in MOGAD and AQP4-IgG-NMOSD, but not MS. The prognosis of MOGAD was better than AQP4-IgG-NMOSD. In contrast to MS, BSIFE may not indicate a worse prognosis for MOGAD. When patients with BSIFE, MOGAD tent to reoccur in the brainstem. Four of the 14 recurring MOGAD patients relapsed after the MOG-IgG test turned negative.

A Case of Myelin Oligodendrocyte Glycoprotein Antibody-Associated Optic Neuritis Responsive to Intravenous Immunoglobulin (IVIG) Therapy in a Pediatric Patient

We present a case of an eight-year-old boy who presented with complaints of headache, blurry vision, and eye pain. Ophthalmological exams and magnetic resonance imaging confirmed the presence of optic neuritis. Initial cerebrospinal fluid analysis was negative for all antibodies (Abs) associated with optic neuritis and other acute demyelinating syndromes, including anti-myelin oligodendrocyte glycoprotein Ab (anti-MOG-Ab). The child was treated with a course of pulse methylprednisolone therapy for five days, with significant improvement in his symptoms. However, the child went on to have a recurrent episode of optic neuritis one month after his initial presentation. Hence, investigations targeting immunological biomarkers were repeated and turned out to be positive for anti-MOG-Abs with elevated titers. The child was diagnosed with MOG-Ab-associated optic neuritis presenting as chronic relapsing inflammatory optic neuropathy (CRION). He was then started on maintenance intravenous immunoglobulin (IVIG) therapy as a disease-modifying therapy, following which he has not had any further relapses over two years.

Clinical characteristics of myelin oligodendrocyte glycoprotein antibody-associated disease according to their epitopes

Background

The detection of myelin oligodendrocyte glycoprotein autoantibodies (MOG-Ab) is essential for the diagnosis of MOG-Ab-associated disease (MOGAD). The clinical implications of different epitopes recognized by MOG-Ab are largely unknown. In this study, we established an in-house cell-based immunoassay for detecting MOG-Ab epitopes and examined the clinical characteristics of patients with MOG-Ab according to their epitopes.

Methods

We conducted a retrospective review of patients with MOG-Ab-associated disease (MOGAD) in our single center registry, and collected serum samples from enrolled patients. Human MOG variants were generated to detect epitopes recognized by MOG-Ab. The differences in clinical characteristics according to the presence of reactivity to MOG Proline42 (P42) were evaluated.

Results

Fifty five patients with MOGAD were enrolled. Optic neuritis was the most common presenting syndrome. The P42 position of MOG was a major epitope of MOG-Ab. The patients with a monophasic clinical course and childhood-onset patients were only observed in the group that showed reactivity to the P42 epitope.

Conclusion

We developed an in-house cell-based immunoassay to analyze the epitopes of MOG-Ab. The P42 position of MOG is the primary target of MOG-Ab in Korean patients with MOGAD. Further studies are needed to determine the predictive value of MOG-Ab and its epitopes.

Acute disseminated encephalomyelitis (ADEM) following COVID-19 vaccination: A systematic review

BACKGROUND

Although global vaccination against COVID-19 infection has its excellence, potential side effects are yet of concern. Several lines of evidence have proposed ADEM occurrence after SARS-CoV-2 infection. Moreover, a large number of case reports and case series have also suggested the casual association between ADEM and COVID-19 vaccination. To better understand the development of ADEM following COVID-19 vaccination and its potential association, we aimed to systematically review ADEM cases reported after COVID-19 vaccination.

METHODS

We conducted a comprehensive systematic search using three databases including PubMed, Scopus, and Web of Science. Studies that reported ADEM after COVID-19 vaccination were eligible to include in our study. Observational studies, case reports, and case series which reported cases of ADEM with sufficient detail to confirm clinical diagnosis following COVID-19 vaccination were eligible to enter our study.

RESULTS

Twenty studies were included in our systematic review after the abstract and full-text screening with a total of 54 cases. Among included patients, 45 (85.1 %) developed ADEM after the first dose of the COVID-19 vaccine, and seven (12.9 %) cases experienced ADEM after the second dose. The median time interval between vaccination and neurological symptoms was 14 days which ranged from 12 h to 63 days. Twelve (22.2 %) patients experienced symptoms of muscle weakness, ten (18.5 %) presented unconsciousness, nine (16.6 %) patients had urinary complaints, nine (16.6 %) had visual impairments, and five (9.2 %) experienced a seizure. After treatments, four (13.8 %) patients died. Forty-six patients had clinical improvement (85.1 %), also improvement in brain MRI was observed among 44 (81.4 %) patients.

CONCLUSION

In conclusion, it is not clear that ADEM could be a potential complication of COVID-19 vaccination based on the current evidence and further studies are needed. However, this rare condition should not trigger stopping the mass vaccination programs since the only way to eradicate the current pandemic of COVID-19 is to extend the number of immunized people.

Pathophysiology of myelin oligodendrocyte glycoprotein antibody disease

Myelin Oligodendrocyte Glycoprotein Antibody Disease (MOGAD) is a spectrum of diseases, including optic neuritis, transverse myelitis, acute disseminated encephalomyelitis, and cerebral cortical encephalitis. In addition to distinct clinical, radiological, and immunological features, the infectious prodrome is more commonly reported in MOGAD (37-70%) than NMOSD (15-35%). Interestingly, pediatric MOGAD is not more aggressive than adult-onset MOGAD, unlike in multiple sclerosis (MS), where annualized relapse rates are three times higher in pediatric-onset MS. MOGAD pathophysiology is driven by acute attacks during which T cells and MOG antibodies cross blood brain barrier (BBB). MOGAD lesions show a perivenous confluent pattern around the small veins, lacking the radiological central vein sign. Initial activation of T cells in the periphery is followed by reactivation in the subarachnoid/perivascular spaces by MOG-laden antigen-presenting cells and inflammatory CSF milieu, which enables T cells to infiltrate CNS parenchyma. CD4+ T cells, unlike CD8+ T cells in MS, are the dominant T cell type found in lesion histology. Granulocytes, macrophages/microglia, and activated complement are also found in the lesions, which could contribute to demyelination during acute relapses. MOG antibodies potentially contribute to pathology by opsonizing MOG, complement activation, and antibody-dependent cellular cytotoxicity. Stimulation of peripheral MOG-specific B cells through TLR stimulation or T follicular helper cells might help differentiate MOG antibody-producing plasma cells in the peripheral blood. Neuroinflammatory biomarkers (such as MBP, sNFL, GFAP, Tau) in MOGAD support that most axonal damage happens in the initial attack, whereas relapses are associated with increased myelin damage.

Early Immunotherapy and Longer Corticosteroid Treatment Are Associated With Lower Risk of Relapsing Disease Course in Pediatric MOGAD

BACKGROUND AND OBJECTIVES

We sought to identify early factors associated with relapse and outcome in paediatric-onset myelin oligodendrocyte glycoprotein antibody-associated disorders (MOGAD).

METHODS

In a multicenter retrospective cohort of pediatric MOGAD (≤18 years), onset features and treatment were compared in patients with monophasic vs relapsing disease (including cases with follow-up ≥12 months after onset or relapse at any time) and in patients with final Expanded Disability Status Scale (EDSS) 0 vs ≥1 at last follow-up (including cases with follow-up >3 months after last event or EDSS0 at any time). Multivariable logistic regression models were used to evaluate factors associated with relapsing disease course and EDSS ≥ 1 at final follow-up.

RESULTS

Seventy-five children were included (median onset age 7 years; median 30 months of follow-up). Presentation with acute disseminated encephalomyelitis was more frequent in children aged 8 years or younger (66.7%, 28/42) than in older patients (30.3%, 10/33) (p = 0.002), whereas presentation with optic neuritis was more common in children older than 8 years (57.6%, 19/33) than in younger patients (21.4%, 9/42) (p = 0.001). 40.0% (26/65) of patients relapsed. Time to first relapse was longer in children aged 8 years or younger than in older patients (median 18 vs 4 months) (p = 0.013). Factors at first event independently associated with lower risk of relapsing disease course were immunotherapy <7 days from onset (6.7-fold reduced odds of relapsing course, OR 0.15, 95% CI 0.03-0.61, p = 0.009), corticosteroid treatment for ≥5 weeks (6.7-fold reduced odds of relapse, OR 0.15, 95% CI 0.03-0.80, p = 0.026), and abnormal optic nerves on onset MRI (12.5-fold reduced odds of relapse, OR 0.08, 95% CI 0.01-0.50, p = 0.007). 21.1% (15/71) had EDSS ≥ 1 at final follow-up. Patients with a relapsing course had a higher proportion of final EDSS ≥ 1 (37.5%, 9/24) than children with monophasic disease (12.8%, 5/39) (p = 0.022, univariate analysis). Each 1-point increment in worst EDSS at onset was independently associated with 6.7-fold increased odds of final EDSS ≥ 1 (OR 6.65, 95% CI 1.33-33.26, p = 0.021).

DISCUSSION

At first attack of pediatric MOGAD, early immunotherapy, longer duration of corticosteroid treatment, and abnormal optic nerves on MRI seem associated with lower risk of relapse, whereas higher disease severity is associated with greater risk of final disability (EDSS ≥ 1).