E.U. paediatric MOG consortium consensus: Part 5 - Treatment of paediatric myelin oligodendrocyte glycoprotein antibody-associated disorders

Emergent Management of Central Nervous System Demyelinating Disorders

OBJECTIVE

This article reviews the various conditions that can present with acute and severe central nervous system demyelination, the broad differential diagnosis of these conditions, the most appropriate diagnostic workup, and the acute treatment regimens to be administered to help achieve the best possible patient outcomes.

LATEST DEVELOPMENTS

The discovery of anti-aquaporin 4 (AQP4) antibodies and anti-myelin oligodendrocyte glycoprotein (MOG) antibodies in the past two decades has revolutionized our understanding of acute demyelinating disorders, their evaluation, and their management.

ESSENTIAL POINTS

Demyelinating disorders comprise a large category of neurologic disorders seen by practicing neurologists. In the majority of cases, patients with these conditions do not require care in an intensive care unit. However, certain disorders may cause severe demyelination that necessitates intensive care unit admission because of numerous simultaneous multifocal lesions, tumefactive lesions, or lesions in certain brain locations that lead to acute severe neurologic dysfunction. Intensive care may be necessary for the management and prevention of complications for patients who have severely altered mental status, rapidly progressive neurologic worsening, elevated intracranial pressure, severe cerebral edema, status epilepticus, or respiratory failure.

Moyamoya disease in a 5-year child secondary to MOG antibody-positive cerebral cortical encephalitis

A 5-year-old girl presented with complaints of fever, left-sided hemiparesis, and left upper motor neuron facial nerve palsy following oral polio booster dose vaccination. She had a past history of fever with altered sensorium with complete resolution at 3 years of age. Cerebrospinal fluid evaluation and stool examination were inconclusive. MRI with MRA showed T2 hyperintensities of the right fronto-temporo-parietal cortex with diffusion restriction and occlusion of bilateral internal carotid arteries and collateral formation suggestive of Moyamoya disease with cerebral cortical encephalitis. Evaluation of encephalitis revealed positivity for anti-myelin oligodendrocyte (MOG) antibodies. She showed a good response to intravenous immunoglobulin and pulse steroids with resolution of encephalitis and facial nerve palsy and improvement in the power of the left side of the body. We presume that the Moyamoya disease in this case is possibly secondary to myelin oligodendrocyte antibody-associated disease.

Clinico-radiologic Spectrum and Outcome of Pediatric Acquired Demyelinating Disorders of Central Nervous System: A Retrospective Indian Tertiary Care Hospital Cohort

BACKGROUND

 Pediatric acquired demyelinating syndrome (ADS) constitutes a group of treatable disorders with acute neurologic dysfunction. Neuroimaging has played a significant role in diagnosis of ADS. We describe clinico-radiologic spectrum, outcomes, and comparison of the groups: acute disseminated encephalomyelitis (ADEM), neuromyelitis optica spectrum disorder (NMOSD), clinically isolated syndrome (CIS), multiple sclerosis (MS), and myelin oligodendrocyte glycoprotein antibody-associated disorders (MOGAD).

METHODS

 Retrospective review of 70 children with ADS at a tertiary care hospital over 15 years (2008-2023) was performed. Diagnosis was assigned as per International Pediatric Multiple Sclerosis Study Group criteria 2016. Fisher's exact and chi-square tests were applied.

RESULTS

 Thirty-nine boys and 31 girls aged 8.2 ± 4.0 years with CIS (n = 27), ADEM (n = 16), NMOSD (n = 13), MS (n = 1), and MOGAD (n = 13) were included. Clinical syndromes with positive significant association included polyfocal symptoms, encephalopathy in ADEM, optic neuritis (ON) in MOGAD, brainstem, area postrema syndrome in NMOSD. MOGAD presented with atypical presentations like prolonged fever (PF; 76.9%) and aseptic meningitis (23%). Seropositivity for myelin oligodendrocyte glycoprotein immunoglobulin-G was 62% and for NMO-IgG 2.6%. Neuroimaging of MOGAD showed lesions predominantly in basal ganglia/thalami (69.2%), optic nerve (46.2%), and cerebellum (46.2%). Imaging patterns between ADEM and MOGAD were comparable except for more ON (p = 0.004), spinal cord (p = 0.01), and cerebellar lesions (p = 0.03) in MOGAD. Area postrema lesion was unique to NMOSD. All patients received immunotherapy, of whom 91.4% (n = 64) had good recovery, 8.6% (n = 6) had functional limitation on modified Rankin scale at discharge, and 12 (17.1%) relapsed.

CONCLUSION

 The largest group was CIS. Seropositivity of MOG was high with atypical presentations like PF and aseptic meningitis. Specific neuroimaging patterns correlated with ADS categories. Short-term outcome with immunotherapy was favorable in spite of relapses.

Blood parameters in pediatric myelin oligodendrocyte glycoprotein antibody-associated disorders

BACKGROUND AND OBJECTIVES

Patients with myelin oligodendrocyte glycoprotein antibody-associated disorders (MOGAD) clinically present e.g. with acute disseminated encephalomyelitis (ADEM), optic neuritis (ON), transverse myelitis (TM) or aquaporin-4-IgG (AQP4-IgG) negative neuromyelitis optica spectrum disorders (NMOSD)-like phenotypes. We aimed to analyze and compare blood parameters in children with MOGAD, AQP4-IgG-positive NMOSD (hence NMOSD), multiple sclerosis (MS) and healthy controls (HC).

METHODS

We evaluated differences in complete blood counts (CBC), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR) and C-reactive protein (CRP) between these four groups and within the groups between clinical attack, acute treatment and remission.

RESULTS

Our cohort consisted of 174 children and adolescents with a total of 550 timepoints: 66 patients had MOGAD (202 timepoints), 11 NMOSD (76 timepoints), 58 MS (219 timepoints) and 39 were HC (53 timepoints). At clinical attack, leukocyte counts were elevated in MOGAD compared to remission (p < 0.001) and compared to all other groups (p < 0.001). NLR was high in MOGAD and NMOSD, and PLR was high in NMOSD, however, after correction for multiple testing these findings did not remain significant. While glucocorticoids caused an increase of leukocyte counts and NLR in NMOSD and MS, these values remained stable during acute treatment in MOGAD. In remission, NLR normalized in MOGAD, while it stayed high in NMOSD. PLR increased in NMOSD and was significantly higher compared to all other groups.

DISCUSSION

Some blood parameters, mainly leukocyte and differential counts, might help clinicians to evaluate disease activity, differentiate relapses from pseudo-relapses and even distinguish between different disease entities.

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.

Antibodies to neural cell surface and synaptic proteins in paraneoplastic neurologic syndromes

Among patients with paraneoplastic neurologic syndromes (PNS), emphasis has historically been placed on neural antibodies against intracellular proteins that have a strong association with malignancy. Because of the intracellular location of their antigenic targets, these antibodies are typically considered to be non-pathogenic surrogate markers of immune cell-mediated neural injury. Unfortunately, patients with these antibodies often have suboptimal response to immunotherapy and poor prognosis. Over the last two decades, however, dramatic advancements have been made in the discovery and clinical characterization of neural antibodies against extracellular targets. These antibodies are generally considered to be pathogenic, given their potential to directly alter antigen structure or function, and patients with these antibodies often respond favorably to prompt immunotherapy. These antibodies also associate with tumors and may thus occur as PNS, albeit more variably than neural antibodies against intracellular targets. The updated 2021 PNS diagnostic criteria, which classifies antibodies as high-risk, intermediate-risk, or lower-risk for an associated cancer, better clarifies how neural antibodies against extracellular targets relate to PNS. Using this recently created framework, the clinical presentations, ancillary test findings, oncologic associations, and treatment responses of syndromes associated with these antibodies are discussed.

Mechanisms and Emerging Therapies for Treatment of Seizures in Pediatric Autoimmune Encephalitis and Autoinflammatory/Autoimmune-Associated Epilepsy

There has been increasing understanding of the role of inflammation in seizures and epilepsy, as well as targeted immunomodulatory treatments. In children, immune-mediated seizures often present acutely in the setting of autoimmune encephalitis and are very responsive to immunotherapy with low rates of subsequent epilepsy. Conversely, seizures in autoimmune-associated epilepsies, such as Rasmussen syndrome, can remain refractory to multimodal therapy, including immunomodulation. In this review, the authors discuss the presentations of immune-mediated seizures in children, underlying mechanisms, and emerging therapies.

Pearls & Oy-sters: MOG-AD Meningoencephalitis With Holocord Gray Matter Predominant Myelitis

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) has been implicated in a wide range of CNS encephalitis and myelitis presentations. We present a previously healthy 16-year-old girl who presented with acute onset headaches that rapidly progressed to encephalopathy, flaccid paraparesis, lower extremity hyperreflexia, and urinary retention. Serial MRI brain and total spine imaging demonstrated evolving diffuse supratentorial leptomeningeal enhancement and holocord gray matter restricted T2 bright lesion without enhancement. CSF was markedly inflammatory with MOG antibody positive >1:10,000. The patient improved after empiric steroids, plasma exchange, and IVIG.

Anti-Inflammatory and Immunomodulatory Effect of High-Dose Immunoglobulins in Children: From Approved Indications to Off-Label Use

BACKGROUND

The large-scale utilization of immunoglobulins in patients with inborn errors of immunity (IEIs) since 1952 prompted the discovery of their key role at high doses as immunomodulatory and anti-inflammatory therapy, in the treatment of IEI-related immune dysregulation disorders, according to labelled and off-label indications. Recent years have been dominated by a progressive imbalance between the gradual but constant increase in the use of immunoglobulins and their availability, exacerbated by the SARS-CoV-2 pandemic.

OBJECTIVES

To provide pragmatic indications for a need-based application of high-dose immunoglobulins in the pediatric context.

SOURCES

A literature search was performed using PubMed, from inception until 1st August 2023, including the following keywords: anti-inflammatory; children; high dose gammaglobulin; high dose immunoglobulin; immune dysregulation; immunomodulation; immunomodulatory; inflammation; intravenous gammaglobulin; intravenous immunoglobulin; off-label; pediatric; subcutaneous gammaglobulin; subcutaneous immunoglobulin. All article types were considered.

IMPLICATIONS

In the light of the current imbalance between gammaglobulins' demand and availability, this review advocates the urgency of a more conscious utilization of this medical product, giving indications about benefits, risks, cost-effectiveness, and administration routes of high-dose immunoglobulins in children with hematologic, neurologic, and inflammatory immune dysregulation disorders, prompting further research towards a responsible employment of gammaglobulins and improving the therapeutical decisional process.

Clinical characteristics and long-term follow-up outcomes of myelin oligodendrocyte glycoprotein antibody-associated disease in Han Chinese participants

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is an immune-mediated inflammatory demyelinating disease of the central nervous system. This study aimed to delineate the clinical manifestations, imaging features, and long-term outcomes in Chinese patients with MOGAD and analyze the recurrence-associated factors. The phenotypic and neuroimaging characteristics of 15 Han Chinese patients with MOGAD were retrospectively analyzed. Demyelinating attacks, MOG antibodies in the cerebrospinal fluid/serum, response to immunotherapy, follow-up outcomes, and recurrence-associated factors were recorded. The median age at disease onset was 34 years (range, 4-65 years). The most common initial presentations included vision loss (10/15, 66.7%) and seizures (5/15, 33.3%). Serum MOG-Ab titers in 14/15 cases were higher than those in the cerebrospinal fluid and were detected in 3/6 relapsed patients. Brain magnetic resonance imaging during acute attacks showed lesions in 10/15 patients (66.7%), mostly in the cortex/subcortical white matter (5/15, 33.3%). Recurrence occurred in 6/15 patients (40.0%); in 4 patients, recurrence occurred shortly after immunotherapy discontinuation. Residual neurological deficits were present in 5/15 patients (33.3%), including visual impairment, incapacitation, cognitive impairment, and speech reduction. Optic neuritis was the most common clinical manifestation of MOGAD. magnetic resonance imaging findings were heterogeneous and the cerebral cortex/subcortical white matter was the most susceptible brain region. Although patients in the acute phase responded well to methylprednisolone pulse therapy, the long-term recurrence rate was high. Consistently detected serum MOG antibodies and inappropriate maintenance immunotherapy may be associated with recurrence, and residual neurological deficits should not be ignored.

Fulminant Anti-Myelin Oligodendrocyte Glycoprotein-Associated Cerebral Cortical Encephalitis: Case Series of a Severe Pediatric Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease Phenotype

BACKGROUND

We describe a cohort of children with severe myelin oligodendrocyte glycoprotein (MOG)-IgG-associated cerebral cortical encephalitis (CCE), manifesting with bilateral cortical cytotoxic edema and critical neurological illness.

METHODS

We retrospectively reviewed our pediatric MOG antibody-associated disease (MOGAD) database and identified patients with specific radiographic pattern of bilateral, multifocal cortical cytotoxic lesions. We collected demographic, clinical, and outcomes data from these patients and compared select variables with radiographically distinct cerebral MOGAD syndromes (case-control analysis). We assessed the correlation of quantitative clinical variables with severity/outcomes measures using simple linear regression.

RESULTS

Sixty-five of 88 total MOGAD cases had cerebral disease, and six of 88 met inclusion criteria for fulminant CCE (f-CCE). Age range was 2 to 7 years; five of six were male. Six of six were critically ill with severe encephalopathy and seizures, two of six required barbiturate coma, and two of six required invasive intracranial pressure monitoring. Six of six required treatment escalation beyond steroids. Four of six had favorable outcome; two of six had moderate-severe disability. Compared with other cerebral MOGAD cases (n = 59), children with f-CCE were more likely to have critical illness and poor neurological outcomes scores. Neurofilament light chain and treatment latency positively correlated with intensive care unit length of stay and outcomes scores; cerebrospinal fluid (CSF) white blood cell count and neutrophil-to-lymphocyte ratio did not.

CONCLUSIONS

Pediatric CCE with bilateral cytotoxicity is associated with more fulminant disease and worse outcomes than other cerebral MOGAD syndromes.

Pathogenesis, Clinical Features, and Treatment of Patients with Myelin Oligodendrocyte Glycoprotein (MOG) Autoantibody-Associated Disorders Focusing on Optic Neuritis with Consideration of Autoantibody-Binding Sites: A Review

Although there is a substantial amount of data on the clinical characteristics, diagnostic criteria, and pathogenesis of myelin oligodendrocyte glycoprotein (MOG) autoantibody-associated disease (MOGAD), there is still uncertainty regarding the MOG protein function and the pathogenicity of anti-MOG autoantibodies in this disease. It is important to note that the disease characteristics, immunopathology, and treatment response of MOGAD patients differ from those of anti-aquaporin 4 antibody-positive neuromyelitis optica spectrum disorders (NMOSDs) and multiple sclerosis (MS). The clinical phenotypes of MOGAD are varied and can include acute disseminated encephalomyelitis, transverse myelitis, cerebral cortical encephalitis, brainstem or cerebellar symptoms, and optic neuritis. The frequency of optic neuritis suggests that the optic nerve is the most vulnerable lesion in MOGAD. During the acute stage, the optic nerve shows significant swelling with severe visual symptoms, and an MRI of the optic nerve and brain lesion tends to show an edematous appearance. These features can be alleviated with early extensive immune therapy, which may suggest that the initial attack of anti-MOG autoantibodies could target the structures on the blood-brain barrier or vessel membrane before reaching MOG protein on myelin or oligodendrocytes. To understand the pathogenesis of MOGAD, proper animal models are crucial. However, anti-MOG autoantibodies isolated from patients with MOGAD do not recognize mouse MOG efficiently. Several studies have identified two MOG epitopes that exhibit strong affinity with human anti-MOG autoantibodies, particularly those isolated from patients with the optic neuritis phenotype. Nonetheless, the relations between epitopes on MOG protein remain unclear and need to be identified in the future.

Phenotypic characteristics of myelin oligodendrocyte glycoprotein antibody-associated disease in children: a single-center, retrospective study

Objective

To analyze the clinical characteristics and follow-up data of children with different clinical phenotypes of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD).

Methods

The basic demographic and clinical features, laboratory and imaging examination results, and follow-up data of 74 Chinese children with different phenotypes of MOGAD were retrospectively reviewed and analyzed.

Results

The male-to-female ratio in this cohort was 1:1.39. The clinical phenotypes of MOGAD included acute disseminated encephalomyelitis (ADEM; n = 37), encephalitis (n = 11), optic neuritis (ON, n = 9), neuromyelitis optica spectrum disorder (NMOSD; n = 9), transverse myelitis (TM; n = 6), leukodystrophy-like manifestations (n = 1), and meningitis (n = 1). The mean age of disease onset was 86 months. The number of leukocytes in the cerebrospinal fluid of patients with ADEM was significantly higher than that in patients with ON but lower than that in patients with TM (p < 0.05). The pathogen detection rate among all patients was 36.5%. Recurrence occurred in 17 patients (23%), with the highest recurrence rate in patients with NMOSD and TM. Patients with recurrence had a significantly higher median age than those without any recurrence (109.00 vs. 82.44 months, p < 0.05). The male-to-female ratio in patients with recurrence was 1:4.67, which differed significantly from that at first onset (p < 0.05).

Conclusion

The most common clinical phenotypes of MOGAD in this cohort were ADEM and encephalitis. Recurrence of MOGAD may be related to age and sex, with a higher recurrence rate observed in females. These findings provide a basis for further exploration of the characteristics of different MOGAD phenotypes.

Myelin oligodendrocyte glycoprotein antibody-associated disease as a novel presentation of central nervous system autoimmunity in a pediatric patient with Wiskott-Aldrich syndrome

BACKGROUND

Wiskott-Aldrich syndrome (WAS) is an X-linked primary immunodeficiency caused by mutations in the WAS gene that leads to increased susceptibility to infections, thrombocytopenia, eczema, malignancies, and autoimmunity. Central nervous system (CNS) autoimmune manifestations are uncommon.

CASE PRESENTATION

We describe the case of a five-year-old boy with refractory thrombocytopenia and iron deficiency anemia who developed relapsing bilateral optic neuritis. Myelin oligodendrocyte glycoprotein antibody (MOG-IgG) via serum fluorescence-activated cell sorting assay was positive (titer 1:100), confirming a diagnosis of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). At age six, molecular panel testing for genes associated with primary immunodeficiency identified a missense WAS gene variant. He was subsequently found to have decreased WAS protein expression, consistent with a diagnosis of WAS.

CONCLUSIONS

This case expands the reported spectrum of CNS autoimmunity associated with WAS and may help to inform long-term therapeutic options.

Intravenous immunoglobulin treatment for acute attacks in myelin oligodendrocyte glycoprotein antibody disease

BACKGROUND

The potential therapeutic benefit of intravenous immunoglobulins (IVIGs) for acute attacks of myelin oligodendrocyte glycoprotein antibody disease (MOGAD) is unknown.

OBJECTIVE

The objective was to describe the outcomes of IVIG treatment for acute MOGAD attacks.

METHODS

A retrospective observational study involving seven tertiary neuroimmunology centers. Data collection included patients' demographics, Expanded Disability Status Scale (EDSS), and visual acuity (VA) before the attack, at the nadir of the attack before IVIG treatment, and at follow-up visits ⩾3 months after treatment.

RESULTS

Thirty-nine patients were included, of which 21 (53.8%) were female. The median age was 23 years (range 5-74 years), and the median disease duration was 4 months (range 0-93 months). The most common type of attack treated with IVIG was isolated optic neuritis (ON) (unilateral n = 14, bilateral n = 5, associated with transverse myelitis (TM), n = 1), followed by acute disseminated encephalomyelitis (ADEM) (n = 8), multifocal (n = 7), TM (n = 3), brainstem (n = 1), and other encephalitis (n = 1). A significant improvement in both the EDSS and VA measures was observed at follow-up compared to the time of IVIG treatment initiation (p < 0.0001 for both outcome measures).

CONCLUSION

IVIG may be an effective treatment option for acute MOGAD attacks. Further prospective studies are warranted to validate our results.

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.

Attack phenotypes and disease course in pediatric MOGAD

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is an autoimmune demyelinating condition that affects children differently than adults. We performed a literature review to assess the presentation and clinical course of pediatric MOGAD. The most common initial phenotype is acute disseminated encephalomyelitis, especially among children younger than five years, followed by optic neuritis (ON) and/or transverse myelitis. Approximately one-quarter of children with MOGAD have at least one relapse that typically occurs within three years of disease onset and often includes ON, even if ON was not present at onset. Clinical risk factors for a relapsing course have not been elucidated.

Transverse myelitis in children and adults

Transverse myelitis is a noncompressive myelopathy of inflammatory origin. The causes are broad, ranging from infective or toxic to immuno-mediated etiology. They can be manifestations of systemic diseases, such as sarcoidosis and systemic lupus erythematous, or phenotypes of neuroinflammation; in a portion of cases, the etiology remains unknown, leading to the designation idiopathic. The clinical presentation of transverse myelitis depends on the level of spinal cord damage and may include sensorimotor deficits and autonomic dysfunction. The age of onset of the disorder can impact the symptoms and outcomes of affected patients, with differences in manifestation and prognosis between children and adults. Spinal cord magnetic resonance imaging and cerebrospinal fluid examination are the main diagnostic tools that can guide clinicians in the diagnostic process, even though the search for antibodies that target the structural components of the neural tissue (anti-aquaporin4 antibodies and anti-myelin-oligodendrocyte antibodies) helps in the distinction among the immune-mediated phenotypes. Management and outcomes depend on the underlying cause, with different probabilities of relapse according to the phenotypes. Hence, immunosuppression is often recommended for the immune-mediated diseases that may have a higher risk of recurrence. Age at onset has implications for the choice of treatment.

Indications and Safety of Rituximab in Pediatric Neurology: A 10-Year Retrospective Study

BACKGROUND

RTX is used off-label in several neurological inflammatory diseases in adults children patients. We conducted a study to assess indications and safety of rituximab (RTX) for children and to identify risk factors for early B-cell repopulation.

METHODS

A single-center retrospective study of children treated with RTX for a neurological disease between May 31, 2010, and May 31, 2020, was performed.

RESULTS

A total of 77 children (median age, 8.9 years) were included. RTX was mostly used as second-line therapy in all groups of diseases (68%). Median dose was 1500 mg/m² for each patient. There were 13 clinical relapses (17%), 5 when B-cell depletion was complete. Adverse events were present in 6% of the cases. The factors influencing early B-cell repopulation were the recent infusion of intravenous Ig (P < 0.01) and the administration of less than 1500 mg/m² during the first RTX treatment (P = 0.04). The median time to B-cell repopulation seemed to be shorter (160 vs 186 days) when patients had plasmapheresis even when a 48-hour delay was observed with RTX infusions.

CONCLUSIONS

This study confirms the good tolerance of RTX in the treatment of specific neurological disorders in a pediatric population. It also highlights risk factors for early B-cell repopulation and underlines the importance of B-cell monitoring.

Mycophenolate mofetil: An alternative disease-modifying agent for MOG-IgG-associated disorders in childhood: A single-center bidirectional cohort study

OBJECTIVE

To evaluate the efficacy of mycophenolate mofetil (MMF) in the treatment of childhood MOG-IgG-associated disorder (MOGAD).

METHODS

Thirty patients diagnosed with relapsing MOGAD and treated with MMF for >1 year from a childhood MOGAD ambispective cohort were included in the study. The clinical characteristics, therapeutic regimen, side effects, annualized relapse rate (ARR), and Expanded Disability Status Scale (EDSS) scores of these patients were evaluated.

RESULTS

The median age of disease onset was 7.05 (2.50-12.75) years. The male to female ratio was 1:1.31. All patients used MMF as first-line maintenance treatment. The median time to add MMF from disease onset was 1.08 (0.25-5.00) year. The median number of attacks before MMF initiation was 2 (2 - 8). The median duration of MMF therapy was 2.13 (1.00-3.58) years. Twenty (66.67%) patients did not experience further attacks during MMF therapy. The Kaplan-Meier curves showed a 3-year relapse-free rate of 59.8% (95% CI, 36.62-76.88%). ARR decreased during MMF therapy (0 (0 - 1.72) vs. 1.25 (0.60-4.00); P < 0.05). EDSS stabilized during MMF therapy (1.0 (0 - 2.0) vs. 0 (0 - 2.0); P = 0.206). None of the patients stopped the use of MMF due to intolerable side effects. Onset age, sex, phenotype of the first attack, ARR before MMF, MOG-IgG titers, and combined long-term prednisone (prednisone <10 mg daily for patients >40 kg or <5 mg daily for patients ≤40 kg longer than 6 months) did not predict recurrence during MMF therapy in univariate analysis.

CONCLUSIONS

MMF was effective and safe for treating childhood MOGAD. No clinical feature that could predict efficacy of MMF was found in pediatric patients with MOGAD.

Clinical characteristics of myelin-oligodendrocyte glycoprotein antibody-positive pediatric autoimmune encephalitis without demyelination: A case series

Purpose

To facilitate the identification of myelin-oligodendrocyte glycoprotein (MOG) antibody-associated diseases in pediatric autoimmune encephalitis without demyelination, we explored the clinical characteristics of patients having MOG antibody-positive pediatric autoimmune encephalitis without demyelination in Children's Hospital of Chongqing Medical University, China.

Methods

We reviewed patients' medical records from January 2019 to June 2022 and retrospectively analyzed clinical manifestations, brain magnetic resonance imaging (MRI) findings, laboratory findings, treatments and outcomes of children with autoimmune encephalitis who tested positive for MOG antibodies in serum but for whom demyelination was not detected on MRI.

Results

Eighteen patients (6 boys, 12 girls; median age: 103.2 (range: 36-160) months) were included: 15 tested positive for MOG antibodies in both serum and cerebrospinal fluid (CSF); three tested positive only in serum. The most common clinical symptoms were altered mental status (18/18), fever (16/18), headache (14/18), seizures (6/18) and focal neurologic deficits (5/18). All patients had CSF pleocytosis (median count: 74/µL, range: 14-380/µL); five patients had elevated CSF protein levels (median: 0.85 g/L, range: 0.53-1.48 g/L) simultaneously. CSF glucose levels were normal in all patients. Abnormal electroencephalogram (EEG) results were found in 12 patients: generalized or focal slowing (9/12), focal epileptic discharges (2/12), and generalized slowing and focal epileptic discharges (1/12). Twelve of the 18 patients showed hyperintense T2-weighted lesions on brain MRI in the cortex (6), basal ganglia (5), thalamus (3), cerebellum (4), and brainstem (2). All patients received immunotherapy and had favorable outcomes at discharge (modified Rankin scale score: <2). Three children relapsed once; however, all children had good outcomes at the last follow-up.

Conclusion

MOG antibody-positive pediatric autoimmune encephalitis without demyelination is mainly characterized by prolonged fever, altered mental status, headache, mild-to-moderate increase in cell count in the CSF, and normal or abnormal brain MRI, which may involve any part outside the white matter without specificity. All patients with MOG antibody-positive pediatric autoimmune encephalitis without demyelination had favorable outcomes after immunotherapy, while a few patients relapsed once.

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).

Clinical characteristics and prognosis of pediatric myelin oligodendrocyte glycoprotein antibody-associated diseases in China

Background

Research on myelin oligodendrocyte glycoprotein antibody (MOG-Ab)-associated disease (MOGAD) among Chinese children is relatively rare. Therefore, this study aimed to explore and analyze the clinical characteristics and prognoses of Chinese children with acquired demyelinating syndromes (ADSs) who tested positive or negative for MOG-Ab.

Methods

The clinical data of children with MOGAD who were treated in the Department of Neurology at Shanghai Children's Hospital from January 2017 to October 2021 were retrospectively collected.

Results

Among 90 children with ADSs, 30 were MOG-Ab-positive, and 60 were MOG-Ab-negative. MOG-Ab-positive children experienced more prodromal infections than did MOG-Ab-negative children (P < 0.05). Acute disseminated encephalomyelitis was the most common ADSs in both groups. There were ten cases of a rebound increase in MOG-Ab titers. There were significant differences in the MOG titer-related prognosis and disease time course between the disease relapse group and the non-relapse group (P < 0.01). Among the MOG-Ab-positive patients, the most affected brain areas detected via magnetic resonance imaging (MRI) were the temporal lobe, cerebellar hemispheres, brainstem, and periventricular lesions. The most common shapes of the lesions were commas, triangles, or patches. The average improvement time based on brain MRI was much longer in MOG-Ab-positive than in MOG-Ab-negative children (P < 0.05). The initial treatment time correlated with the disease time course, and the prognosis may be affected by the disease time course and serum MOG-Ab titer (P < 0.05).

Conclusion

The clinical characteristics and imaging features of ADSs differed between MOG-Ab-positive and MOG-Ab-negative children. In addition to existing treatment plans, additional diagnoses and treatment plans should be developed to reduce recurrence and improve the prognoses of children with MOGAD.

Clinical characteristics and associated factors of pediatric acute disseminated encephalomyelitis patients with MOG antibodies: a retrospective study in Hangzhou, China

Background

To explore the clinical characteristics and related factors of children with acute disseminated encephalomyelitis (ADEM) with positive anti-myelin oligodendrocyte glycoprotein (MOG) antibody.

Methods

A retrospective study was conducted and enrolled pediatric ADEM patients who underwent serum MOG antibody detection from May 2017 to August 2020. The patients were divided into two groups: MOG- immunoglobulin G (IgG) positive (n = 35) and MOG-IgG negative (n = 50). We analyzed the clinical characteristics of MOG-IgG-positive ADEM pediatric patients and conducted a comparative analysis between the two groups.

Results

Thirty-five patients (21 males and 14 females) in the MOG-IgG-positive group with encephalopathy, multifocal neurological symptoms, and typical magnetic resonance imaging (MRI) abnormalities were enrolled. They usually had a favorable outcome, while some suffered from relapse. Compared to the MOG-IgG-negative group, MOG-IgG-positive ADEM patients had a longer disease duration (median: 10 vs. 6 days), more meningeal involvement (31.4% vs. 8%) and frontal lobe involvement (82.8% vs. 68%), higher relapse rates (14.3% vs. 2%), lower serum tumor necrosis factor (1–12.4 pg/ml, median 1.7 vs. 1–34 pg/ml, median 2.2) and interferon-gamma (1–9.4 pg/ml, median 1.3 vs. 1–64 pg/ml, median 3) (P < 0.05, respectively). Multivariate logistic regression analysis showed that the longer disease duration, meningeal involvement and frontal lobe involvement were the correlated factors of patients with ADEM with MOG antibody (P < 0.05).

Conclusions

Our findings provide clinical evidence that MOG-IgG positivity is associated with longer disease duration, meningeal involvement, and frontal lobe involvement.

Temporal Dynamics of MOG Antibodies in Children With Acquired Demyelinating Syndrome

Background and Objective

The spectrum of myelin oligodendrocyte glycoprotein (MOG) antibody–associated disorder (MOGAD) comprises monophasic diseases such as acute disseminated encephalomyelitis (ADEM), optic neuritis (ON), and transverse myelitis and relapsing courses of these presentations. Persistently high MOG antibodies (MOG immunoglobulin G [IgG]) are found in patients with a relapsing disease course. Prognostic factors to determine the clinical course of children with a first MOGAD are still lacking. The objective of the study is to assess the clinical and laboratory prognostic parameters for a risk of relapse and the temporal dynamics of MOG‐IgG titers in children with MOGAD in correlation with clinical presentation and disease course.

Methods

In this prospective multicenter hospital-based study, children with a first demyelinating attack and complete data set comprising clinical and radiologic findings, MOG-IgG titer at onset, and clinical and serologic follow-up data were included. Serum samples were analyzed by live cell-based assay, and a titer level of ≥1:160 was classified as MOG-IgG–positive.

Results

One hundred sixteen children (f:m = 57:59) with MOGAD were included and initially diagnosed with ADEM (n = 59), unilateral ON (n = 12), bilateral ON (n = 16), myelitis (n = 6), neuromyelitis optica spectrum disorder (n = 8) or encephalitis (n = 6). The median follow-up time was 3 years in monophasic and 5 years in relapsing patients. There was no significant association between disease course and MOG-IgG titers at onset, sex, age at presentation, or clinical phenotype. Seroconversion to MOG-IgG–negative within 2 years of the initial event showed a significant risk reduction for a relapsing disease course. Forty-two/one hundred sixteen patients (monophasic n = 26, relapsing n = 16) had serial MOG-IgG testing in years 1 and 2 after the initial event. In contrast to relapsing patients, monophasic patients showed a significant decrease of MOG-IgG titers during the first and second years, often with seroconversion to negative titers. During the follow-up, MOG-IgG titers were persistently higher in relapsing than in monophasic patients. Decrease in MOG-IgG of ≥3 dilution steps after the first and second years was shown to be associated with a decreased risk of relapses. In our cohort, no patient experienced a relapse after seroconversion to MOG-IgG–negative.

Discussion

In this study, patients with declining MOG-IgG titers, particularly those with seroconversion to MOG-IgG–negative, are shown to have a significantly reduced relapse risk.

Myelin Oligodendrocyte Glycoprotein-Associated Disorders

PURPOSE OF REVIEW

Anti-myelin oligodendrocyte glycoprotein (MOG) autoantibodies have become a recognized cause of a pathophysiologically distinct group of central nervous system (CNS) autoimmune diseases. MOG-associated disorders can easily be confused with other CNS diseases such as multiple sclerosis or neuromyelitis optica, but they have a distinct clinical phenotype and prognosis.

RECENT FINDINGS

Most patients with MOG-associated disorders exhibit optic neuritis, myelitis, or acute disseminated encephalomyelitis (ADEM) alone, sequentially, or in combination; the disease may be either monophasic or relapsing. Recent case reports have continued to expand the clinical spectrum of disease, and increasingly larger cohort studies have helped clarify its pathophysiology and natural history.

SUMMARY

Anti-MOG-associated disorders comprise a substantial subset of patients previously thought to have other seronegative CNS diseases. Accurate diagnosis is important because the relapse patterns and prognosis for MOG-associated disorders are unique. Immunotherapy appears to successfully mitigate the disease, although not all agents are equally effective. The emerging large-scale data describing the clinical spectrum and natural history of MOG-associated disorders will be foundational for future therapeutic trials.

Update on glial antibody-mediated optic neuritis

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

Effectiveness and tolerability of different therapies in preventive treatment of MOG-IgG-associated disorder: A network meta-analysis

Background

Immunotherapy has been shown to reduce relapses in patients with myelin oligodendrocyte glycoprotein antibody-associated disorder (MOG-AD); however, the superiority of specific treatments remains unclear.

Aim

To identify the efficacy and tolerability of different treatments for MOG-AD.

Methods

Systematic search in Pubmed, Embase, Web of Science, and Cochrane Library databases from inception to March 1, 2021, were performed. Published articles including patients with MOG-AD and reporting the efficacy or tolerability of two or more types of treatment in preventing relapses were included. Reported outcomes including incidence of relapse, annualized relapse rate (ARR), and side effects were extracted. Network meta-analysis with a random-effect model within a Bayesian framework was conducted. Between group comparisons were estimated using Odds ratio (OR) or mean difference (MD) with 95% credible intervals (CrI).

Results

Twelve studies that compared the efficacy of 10 different treatments in preventing MOG-AD relapse, including 735 patients, were analyzed. In terms of incidence of relapse, intravenous immunoglobulins (IVIG), oral corticosteroids (OC), mycophenolate mofetil (MMF), azathioprine (AZA), and rituximab (RTX) were all significantly more effective than no treatment (ORs ranged from 0.075 to 0.34). On the contrary, disease-modifying therapy (DMT) (OR=1.3, 95% CrI: 0.31 to 5.0) and tacrolimus (TAC) (OR=5.9, 95% CrI: 0.19 to 310) would increase the incidence of relapse. Compared with DMT, IVIG significantly reduced the ARR (MD=−0.85, 95% CrI: −1.7 to −0.098). AZA, MMF, OC and RTX showed a trend to decrease ARR, but those results did not reach significant differences. The combined results for relapse rate and adverse events, as well as ARR and adverse events showed that IVIG and OC were the most effective and tolerable therapies.

Conclusions

Whilst DMT should be avoided, IVIG and OC may be suited as first-line therapies for patients with MOG-AD. RTX, MMF, and AZA present suitable alternatives.

Evidence of neuroinflammation and immunotherapy responsiveness in individuals with down syndrome regression disorder

Background

Down syndrome regression disorder is a symptom cluster consisting of neuropsychiatric regression without cause. This study evaluated the incidence of neurodiagnostic abnormalities in individuals with Down syndrome regression disorder and determined if abnormalities are indicative of responses to therapeutic intervention.

Methods

A retrospective, multi-center, case-control study was performed. Patients were required to have subacute onset and the presence of four of five symptom groups present (cognitive decline, expressive language, sleep derangement, loss of ability to perform activities of daily living, and/or a new movement disorder) and no other explanation for symptoms.

Results

Individuals with Down syndrome regression disorder were comparable to a cohort of individuals with only Down syndrome although had higher rates of autoimmune disease (p = 0.02, 95%CI 1.04–1.75). Neurodiagnostic abnormalities were found on EEG (n = 19, 26%), neuroimaging (n = 16, 22%), and CSF (n = 9, 17%). Pleocytosis was appreciated in five cases, elevated total protein in nine, elevated IgG index in seven, and oligoclonal bands in two. Testing within 2 years of symptom onset was more likely to have neurodiagnostic abnormalities (p = 0.01, 95%CI 1.64–37.06). In individuals with neurodiagnostic abnormalities, immunotherapy was nearly four times more likely to have a therapeutic effect than in those without neurodiagnostic abnormalities (OR 4.11, 95%CI 1.88–9.02). In those with normal neurodiagnostic studies (n = 43), IVIg was effective in 14 of 17 (82%) patients as well although other immunotherapies were uniformly ineffective.

Conclusions

This study reports the novel presence of neurodiagnostic testing abnormalities in individuals with Down syndrome regression disorder, providing credence to this symptom cluster potentially being of neurologic and/or neuroimmunologic etiology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s11689-022-09446-w.

Monoclonal Antibody Therapies Beyond Complement for NMOSD and MOGAD

Aquaporin-4 (AQP4)-IgG seropositive neuromyelitis optica spectrum disorders (AQP4-IgG seropositive NMOSD) and myelin oligodendrocyte glycoprotein (MOG)-IgG-associated disease (MOGAD) are inflammatory demyelinating disorders distinct from each other and from multiple sclerosis (MS).While anti-CD20 treatments can be used to treat MS and AQP4-IgG seropositive NMOSD, some MS medications are ineffective or could exacerbate AQP4-IgG seropositive NMOSD including beta-interferons, natalizumab, and fingolimod. AQP4-IgG seropositive NMOSD has a relapsing course in most cases, and preventative maintenance treatments should be started after the initial attack. Rituximab, eculizumab, inebilizumab, and satralizumab all have class 1 evidence for use in AQP4-IgG seropositive NMOSD, and the latter three have been approved by the US Food and Drug Administration (FDA). MOGAD is much more likely to be monophasic than AQP4-IgG seropositive NMOSD, and preventative therapy is usually reserved for those who have had a disease relapse. There is a lack of any class 1 evidence for MOGAD preventative treatment. Observational benefit has been suggested from oral immunosuppressants, intravenous immunoglobulin (IVIg), rituximab, and tocilizumab. Randomized placebo-controlled trials are urgently needed in this area.

A case of bilateral limbic and recurrent unilateral cortical encephalitis with anti-myelin oligodendrocyte glycoprotein antibody positivity

BACKGROUND

Anti-myelin oligodendrocyte glycoprotein (MOG) antibody can be detected not only in acute disseminated encephalomyelitis or optic neuritis but also in limbic or cortical encephalitis. However, no previous reports have demonstrated a relapsing case of these two types of encephalitis.

CASE REPORT

An 11-year-old girl presented with fever, headache, abnormal behavior, focal impaired awareness seizures (FIAS) on the left side, and MRI hyperintensities in the bilateral amygdala, hippocampus, and right posterior temporal cortex. The symptoms were alleviated with two courses of intravenous methylprednisolone (IVMP) and one course of immunoglobulin. At 16 years of age, the patient returned with left-sided headache and MRI hyperintensities in the left temporal, parietal, and insular cortices, which improved after 3 courses of IVMP. Oral prednisolone (PSL) was tapered over 6 months, when FIAS reappeared on the right side of the body. MRI showed recurrence in the same regions as in the second episode. She received 3 courses of IVMP, followed by gradually tapered PSL without relapse for 1.5 year. Anti-MOG antibodies were positive in both serum and the cerebrospinal fluid prior to treatment in all three episodes.

CONCLUSION

Our results revealed that anti-MOG antibody-related bilateral limbic and unilateral cortical encephalitis can manifest with a variety of phenotypes over time in the same patient.

Comparative study of AQP4-NMOSD, MOGAD and seronegative NMOSD: a single-center Belgian cohort

Purpose

To emphasize physio-pathological, clinical and prognosis differences between conditions causing serious and sometimes very similar clinical manifestations: anti-aquaporin-4 (AQP4) and anti-myelin oligodendrocyte glycoprotein (MOG) antibodies related diseases, and seronegative NMOSD (neuromyelitis optica spectrum disorders).

Methods

Based on Wingerchuk et al. (Neurology 85:177–189, 2015) criteria for NMOSD and on those more recently proposed by Jarius et al. (J Neuroinflammation 15:134, 2018) for MOGAD (MOG associated disorders), we retrospectively surveyed 10 AQP4-NMOSD, 8 MOGAD and 2 seronegative NMOSD, followed at the specialized neuroimmunology unit of the CHU Liège.

Results

Female predominance was only observed in AQP4 group. Age at onset was 37.8 and 27.7 years old for AQP4-NMOSD and MOGAD respectively. In both groups, the first clinical event most often consisted of optic neuritis (ON), followed by isolated myelitis. Fifteen of our 20 patients encountered a relapsing course with 90% relapses in AQP4-NMOSD, 62.5% in MOGAD and 50% in seronegative group, and a mean period between first and second clinical event of 7.1 and 4.8 months for AQP4-NMOSD and MOGAD, respectively. In total we counted 54 ON, with more ON per patient in MOGAD. MOG-associated ON mainly affected the anterior part of the optic nerve with a papilledema in 79.2% of cases. Despite a fairly good visual outcome after MOG-associated ON, retinal nerve fibre layer (RNFL) thickness decreased, suggesting a fragility of the optic nerve toward further attacks.

Conclusion

As observed in larger cohorts, our MOGAD and AQP4-NMOSD cases differ by clinical and prognostic features. A better understanding of these diseases should encourage prompt biological screening and hasten proper diagnosis and treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13760-021-01712-3.

Pediatric acute disseminated encephalomyelitis associated with myelin oligodendrocyte glycoprotein antibodies

Introduction. Myelin oligodendrocyte glycoprotein antibody associated disorders (MOGAD) are immune-mediated inflammatory conditions of the central nervous system (CNS) with a wide clinical phenotypic variability. In order to further understand the possible phenotype of MOGAD here we report a pediatric case of acute disseminated encephalomyelitis (ADEM) associated with MOG antibodies. Case outline. A previously healthy four-month-old infant presented due to a 1-day history of fever up to 39?C and vomiting. On admission, she was encephalopathic. Repetitive and frequent stereotyped dystonic movements were observed. Cerebrospinal fluid (CSF) examination showed pleocytosis (lymphocytes were predominant) and proteinorachy. CSF culture and virology results were negative. Serum MOG antibodies were positive. A prolonged electroencephalography (EEG) showed continuous high-amplitude slow rhythmic activity with captured stereotyped movement. Epileptic discharges were not seen. Although magnetic resonance imaging showed signs of acute demyelinating encephalomyelitis, our patient did not have seizures, despite neuroimaging findings of cortical lesions. Acute treatment with the corticosteroids led to excellent response with full recovery. Conclusion. This case emphasizes the inclusion of the MOG antibodies testing in the initial work-up in children presenting with acute encephalopathy associated with demyelinating or encephalitic abnormalities on brain and/or spinal magnetic resonance imaging even when the clinical phenotype is unusual. The prompt diagnosis of MOGAD is relevant for accurate disease monitoring and treatment strategies.

Multiple Sclerosis in Children: Differential Diagnosis, Prognosis, and Disease-Modifying Treatment

Pediatric-onset multiple sclerosis (POMS) is a rare neuroinflammatory and neurodegenerative disease that has a significant impact on long-term physical and cognitive patient outcomes. A small percentage of multiple sclerosis (MS) diagnoses occur before the age of 18 years. Before treatment initiation, a careful differential diagnosis and exclusion of other similar acquired demyelinating syndromes such as anti-aquaporin-4-associated neuromyelitis optica spectrum disorder (AQP4-NMOSD) and myelin oligodendrocyte glycoprotein antibody spectrum disorder (MOGSD) is warranted. The recent 2017 changes to the McDonald criteria can successfully predict up to 71% of MS diagnoses and have good specificity of 95% and sensitivity of 71%. Additional measures such as the presence of T1-weighted hypointense lesions and/or contrast-enhancing lesions significantly increase the accuracy of diagnosis. In adults, early use of disease-modifying therapies (DMTs) is instrumental to a better long-term prognosis, including lower rates of relapse and disability worsening, and numerous FDA-approved therapies for adult-onset MS are available. However, unlike their adult counterparts, the development, testing, and regulatory approval of POMS treatments have been significantly slower and hindered by logistic and/or ethical considerations. Currently, only two MS DMTs (fingolimod and teriflunomide) have been tested in large phase III trials and approved by regulatory agencies for use in POMS. First-line therapies not approved by the FDA for use in children (interferon-β and glatiramer acetate) are also commonly used and result in a significant reduction in inflammatory activity when compared with non-treated POMS patients. An increasing number of POMS patients are now treated with moderate efficacy therapies such as dimethyl fumarate and high-efficacy therapies such as natalizumab, anti-CD20 monoclonal antibodies, anti-CD52 monoclonal antibodies, and/or autologous hematopoietic stem cell transplantation. These high-efficacy DMTs generally provide additional reduction in inflammatory activity when compared with the first-line medications (up to 62% of relapse-rate reduction). Therefore, a number of phase II and III trials are currently investigating their efficacy and safety in POMS patients. In this review, we discuss potential changes in the regulatory approval process for POMS patients that are recommended for DMTs already approved for the adult MS population, including smaller sample size for pharmacokinetic/pharmacodynamic studies, MRI-centered primary outcomes, and/or inclusion of teenagers in the adult trials.

Pathogenic antibodies to AQP4: Neuromyelitis optica spectrum disorder (NMOSD)

NMOSD is a rare but severe relapsing remitting demyelinating disease that affects both adults and children. Most patients have pathogenic antibodies that target the central nervous system AQP4 protein. This review provides an update on our current understanding of the disease pathophysiology and describes the clinical, paraclinical features and therapeutic management of the disease.

Management of Acute Demyelinating Attacks in the Pediatric Population: A Swiss Consensus Statement

Background and methods: Acquired demyelinating syndromes (ADS) encompass distinct entities and occur in approximately 1/100,000 children. While the use of high dose intravenous corticosteroids is well-established, agreement on steroid taper and type of second line therapy is lacking. A comprehensive, unified and standardized treatment approach is crucial in the management of patients with rare diseases. Therefore, this study performed from July 2018 to June 2020 aimed at developing a national consensus on the management of ADS in the pediatric population using the Delphi approach. Consensus was defined as agreement in >75%. Designated Neuropediatricians with an expertise in the management of pediatric neuroinflammatory diseases in all university and cantonal hospitals of Switzerland were included. The response rate was 100%. Results: High-dose i.v. methylprednisolone (20–30 mg/kg/die for 5 days) is the first line treatment irrespective of the distinct entity of the ADS. An oral steroid taper is recommended in acute demyelinating encephalomyelitis (ADEM) and in neuromyelitis optica spectrum disorder (NMO-SD). However, in the latter more in the sense of bridging. The choice of second line treatment depends on the entity of ADS: in optic neuritis (ON) and ADS due to relapsing remitting multiple sclerosis, first line treatment should be repeated, whereas plasma exchange is recommended in NMO-SD, ADEM and transverse myelitis. Conclusions: A national guideline allowing for a more unified approach in the management of pediatric ADS will enhance future research in this field, making data more comparable. The definition of inadequate treatment response to first line therapy remains a challenge and requires future research.

Treatment of MOG-IgG associated disease in paediatric patients: A systematic review

Aim to perform a systematic review of the literature on treatment of paediatric patients with MOG-IgG associated disease (MOGAD). Method We followed the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) statement. The search was conducted in Pubmed (MEDLINE) seeking articles of treatment of MOGAD in patients ≤ 18 years published between January 2012 and April 25th, 2020. Results We found 72 non-controlled studies (observational studies, case reports and expert recommendations). There were no randomized controlled trials (RCTs). The most commonly reported acute phase treatment was intravenous methylprednisolone in 88% followed by oral steroids in 67%, intravenous human immunoglobulin (IVIG) in 66% and plasma exchange in 33% of the studies. Long-term maintenance treatment was described by 53 studies mainly in relapsing disease course. The most frequently reported treatments were prolonged oral corticosteroids in 53% of the studies followed by azathioprine (51%), mycophenolate mofetil (45%), rituximab (41%) and periodic intravenous immunoglobulin (26%). Interpretation long-term treatment was reported mainly in relapsing MOGAD paediatric patients. However, the most frequently used medications are not those that have shown higher reduction in the annualised relapse rate in observational studies. RCTs with standardized outcomes are needed to confirm the safety and efficacy of current and new treatments.

[Recurrence factors for myelin oligodendrocyte glycoprotein antibody disease in children and the effect of recurrence prevention regimens]

OBJECTIVE

To study the clinical features and recurrence factors of myelin oligodendrocyte glycoprotein (MOG) antibody disease in children and the effect of recurrence prevention regimens.

METHODS

A retrospective analysis was performed on the medical data of 41 children with MOG antibody disease who were hospitalized in the Department of Pediatric Neurology, Xiangya Hospital of Central South University, from December 2014 to September 2020. According to the presence or absence of recurrence, they were divided into a monophasic course group (n=19) and a recurrence group (n=22). According to whether preventive treatment for recurrence was given, the children with recurrence were further divided into a preventive treatment group and a non-preventive treatment group. The clinical features were analyzed for all groups, and the annualized relapse rate (ARR) was compared before and after treatment with prevention regimens.

RESULTS

For these 41 children, acute disseminated encephalomyelitis was the most common initial manifestation and was observed in 23 children (56%). Of the 41 children, 22 (54%) experienced recurrence, with 57 recurrence events in total, among which optic neuritis was the most common event (17/57, 30%). The proportion of children in the recurrence group who were treated with corticosteroids for less than 3 months in the acute phase was higher than that in the monophasic course group (64% vs 32%; P < 0.05). There was no significant difference in the ARR between the preventive treatment and non-preventive treatment groups (P > 0.05). The assessment of preventive treatment regimens for 32 cases showed that the children treated with rituximab or azathioprine had a significant reduction in the ARR during treatment (P < 0.05).

CONCLUSIONS

More than half of the children with MOG antibody disease may experience recurrence. Most children with recurrence are treated with corticosteroids for less than 3 months in the acute phase. Rituximab and azathioprine may reduce the risk of recurrence.

Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease: Presentation, Diagnosis, and Management

Pediatric demyelinating syndromes are a spectrum of diseases affecting the central nervous system. In the past decade, major advances have been made in this field, including the discovery of antibody-based biomarkers and treatment guidelines for specific syndromes. When myelin oligodendrocyte glycoprotein (MOG) antibodies were first discovered, they were thought to be a biomarker for multiple sclerosis (MS). However, further research has shown that MOG positivity during the first episode of a pediatric demyelinating syndrome is a predictor of a course that is distinct to MS. This article discusses the clinical manifestations of MOG antibody associated disease and key distinguishing features in the investigation, treatment, and prognosis between MOG and other demyelinating diseases. [Pediatr Ann. 2021;50(6):e254-e258.].

Update on Acute Disseminated Encephalomyelitis in Children and Adolescents

Acute disseminated encephalomyelitis (ADEM) is an immune-mediated, inflammatory demyelinating disease of the central nervous system (CNS) that usually affects children and young adults after an infection or vaccination. The presence of several conditions mimicking ADEM, added to the lack of specific biomarkers, makes diagnosis potentially hard. Prompt diagnosis is necessary to start adequate treatment to improve the clinical course and long-term outcome. Because of its heterogeneity in both clinical presentation and course, challenges remain in establishing the most appropriate therapeutic approach in each patient. The aim of this review is to provide an update on management of this disease with a focus on acute treatment and to give suggestions for future research. We showed that there are currently no guidelines that help clinicians manage ADEM and therapeutic decisions are often made on a case-by-case basis. Further studies are necessary to identify clinical, laboratory, and instrumental criteria that could be correlated with outcomes and guide clinicians in choosing when and what treatment should be given in each case.

[Aquaporin 4 antibody-positive neuromyelitis optica spectrum disorders and myelin oligodendrocyte glycoprotein antibody-associated encephalomyelitis. A brief review]

Aquaporin 4 (AQP4) immunoglobulin (Ig)G-associated neuromyelitis optica spectrum disorders (NMOSD) and myelin oligodendrocyte glycoprotein immunoglobulin (Ig)G-associated encephalomyelitis (MOG-EM, also termed MOG antibody-associated disease, MOGAD) are important autoimmune differential diagnoses of multiple sclerosis (MS), which differ from MS with respect to optimum treatment and prognosis. AQP4 IgG-positive NMOSD take a relapsing course in virtually all cases and MOG-EM in at least 80% of adult cases. Both diseases can quickly lead to permanent disability if left untreated, although MOG-EM is associated with a better overall long-term prognosis. Antibody testing must be carried out by means of so-called cell-based assays. A number of red flags have been defined that must be checked prior to making a diagnosis of NMOSD or MOG-EM. Acute attacks are treated using high-dose glucocorticoids and plasma exchange or immunoadsorption. Rituximab and other immunosuppressants are used off-label for attack prevention. Recently, eculizumab, a C5 complement inhibitor, has been approved in the European Union (EU) for the treatment of patients with AQP4 IgG-positive NMOSD. This article gives a brief overview of the clinical and paraclinical features, pathology, treatment and prognosis of these rare disorders.

Clinical and Prognostic Analysis of Autoantibody-Associated CNS Demyelinating Disorders in Children in Southwest China

Objective: To analyze the positive and recurrence rates of different autoantibody-associated demyelination disorders in children in Southwest China, and describe the clinical, radiological, and prognostic features of the myelin oligodendrocyte glycoprotein antibody (MOG-ab) and aquaporin-4 antibody (AQP4-ab) associated disease. This study also summarizes steroid maintenance therapy approaches for MOG-ab-positive children. Methods: A total of 160 children presenting with acquired demyelinating syndromes (ADS) between January 2016 and December 2019 were tested for MOG-ab and AQP4-ab. Clinical data, MRI scans, and survival analyses were compared between MOG-ab-positive and AQP4-ab-positive children. Evolution of serologic status and treatment response to immunosuppressants were collected in MOG-ab-positive children. Results: Of the 160 included children, the MOG-ab positivity rate (47.4%) was significantly higher than the AQP4-ab (5%) positivity rate. The recurrence rate for AQP4-ab disease (71.4%) was higher than that of MOG-ab disease (30.1%). For 135 children with both MOG-ab and AQP4-ab tested, the median age at onset was 7 (interquartile range [IQR] 5-10) years, and the median follow-up period was 19 (IQR 13-27.5) months. MOG-ab-positive children more frequently presented with acute disseminated encephalomyelitis, had deep gray matter lesions on MRI, had a better clinical and radiological recovery, and were less likely to have sustained disability than AQP4-ab-positive children. In MOG-ab-positive and AQP4-ab-positive children, maintenance therapy was a protective factor for recurrence, but presenting optic neuritis was a predictor of earlier relapse. A high Expanded Disability Status Scale score at onset was associated with sustained disability. Steroid maintenance therapy longer than 6 months after the initial attack was associated with a lower risk of a second relapse in MOG-ab-positive children. On serial serum MOG antibody analysis, clinical relapse occurred in 34.6% of children with persistent seropositivity, but none of the children who converted to seronegative status experienced relapse. Conclusion: The MOG antibody is more common in children with ADS than the AQP4 antibody. MOG-ab-positive children are characterized by distinct clinical and radiological features. Although some MOG-ab-positive children experience relapsing courses or have persistently seropositive status, they still predict a better outcome than AQP4-ab-positive children.

E.U. paediatric MOG consortium consensus: Part 1 - Classification of clinical phenotypes of paediatric myelin oligodendrocyte glycoprotein antibody-associated disorders

Over the past few years, increasing interest in the role of autoantibodies against myelin oligodendrocyte glycoprotein (MOG-abs) as a new candidate biomarker in demyelinating central nervous system diseases has arisen. MOG-abs have now consistently been identified in a variety of demyelinating syndromes, with a predominance in paediatric patients. The clinical spectrum of these MOG-ab-associated disorders (MOGAD) is still expanding and differs between paediatric and adult patients. This first part of the Paediatric European Collaborative Consensus emphasises the diversity in clinical phenotypes associated with MOG-abs in paediatric patients and discusses these associated clinical phenotypes in detail. Typical MOGAD presentations consist of demyelinating syndromes, including acute disseminated encephalomyelitis (ADEM) in younger, and optic neuritis (ON) and/or transverse myelitis (TM) in older children. A proportion of patients experience a relapsing disease course, presenting as ADEM followed by one or multiple episode(s) of ON (ADEM-ON), multiphasic disseminated encephalomyelitis (MDEM), relapsing ON (RON) or relapsing neuromyelitis optica spectrum disorders (NMOSD)-like syndromes. More recently, the disease spectrum has been expanded with clinical and radiological phenotypes including encephalitis-like, leukodystrophy-like, and other non-classifiable presentations. This review concludes with recommendations following expert consensus on serologic testing for MOG-abs in paediatric patients, the presence of which has consequences for long-term monitoring, relapse risk, treatments, and for counselling of patient and families. Furthermore, we propose a clinical classification of paediatric MOGAD with clinical definitions and key features. These are operational and need to be tested, however essential for future paediatric MOGAD studies.

E.U. paediatric MOG consortium consensus: Part 4 - Outcome of paediatric myelin oligodendrocyte glycoprotein antibody-associated disorders

There is increasing knowledge on the role of antibodies against myelin oligodendrocyte glycoprotein (MOG-abs) in acquired demyelinating syndromes and autoimmune encephalitis in children. Better understanding and prediction of outcome is essential to guide treatment protocol decisions. Therefore, this part of the Paediatric European Collaborative Consensus provides an oversight of existing knowledge of clinical outcome assessment in paediatric MOG-ab-associated disorders (MOGAD). The large heterogeneity in disease phenotype, disease course, treatment and follow-up protocols is a major obstacle for reliable prediction of outcome. However, the clinical phenotype of MOGAD appears to be the main determinant of outcome. Patients with a transverse myelitis phenotype in particular are at high risk of accruing neurological disability (motor and autonomic), which is frequently severe. In contrast, having a single episode of optic neuritis any time during disease course is broadly associated with a lower risk of persistent disability. Furthermore, MOG-ab-associated optic neuritis often results in good functional visual recovery, although retinal axonal loss may be severe. The field of cognitive and behavioural outcome and epilepsy following demyelinating episodes has not been extensively explored, but in recent studies acute disseminated encephalomyelitis (-like) phenotype in the young children was associated with cognitive problems and epilepsy in long-term follow-up. In conclusion, main domains of importance in determining clinical outcome in paediatric MOGAD are visual, motor, autonomic and cognitive function. A standardised evaluation of these outcome domains in all children is of importance to allow adequate rehabilitation and follow-up.