Longitudinal analysis of myelin oligodendrocyte glycoprotein antibodies in CNS inflammatory diseases

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.

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.

The MOG antibody non-P42 epitope is predictive of a relapsing course in MOG antibody-associated disease

BACKGROUND

Myelin oligodendrocyte glycoprotein (MOG) IgG seropositivity is a prerequisite for MOG antibody-associated disease (MOGAD) diagnosis. While a significant proportion of patients experience a relapsing disease, there is currently no biomarker predictive of disease course. We aim to determine whether MOG-IgG epitopes can predict a relapsing course in MOGAD patients.

METHODS

MOG-IgG-seropositive confirmed adult MOGAD patients were included (n=202). Serum MOG-IgG and epitope binding were determined by validated flow cytometry live cell-based assays. Associations between epitopes, disease course, clinical phenotype, Expanded Disability Status Scale and Visual Functional System Score at onset and last review were evaluated.

RESULTS

Of 202 MOGAD patients, 150 (74%) patients had MOG-IgG that recognised the immunodominant proline42 (P42) epitope and 115 (57%) recognised histidine103/serine104 (H103/S104). Fifty-two (26%) patients had non-P42 MOG-IgG and showed an increased risk of a relapsing course (HR 1.7; 95% CI 1.15 to 2.60, p=0.009). Relapse-freedom was shorter in patients with non-P42 MOG-IgG (p=0.0079). Non-P42 MOG-IgG epitope status remained unchanged from onset throughout the disease course and was a strong predictor of a relapsing course in patients with unilateral optic neuritis (HR 2.7, 95% CI 1.06 to 6.98, p=0.038), with high specificity (95%, 95% CI 77% to 100%) and positive predictive value (85%, 95% CI 45% to 98%).

CONCLUSIONS

Non-P42 MOG-IgG predicts a relapsing course in a significant subgroup of MOGAD patients. Patients with unilateral optic neuritis, the most frequent MOGAD phenotype, can reliably be tested at onset, regardless of age and sex. Early detection and specialised management in these patients could minimise disability and improve long-term outcomes.

Myelin Oligodendrocyte Glycoprotein (MOG) Antibody-Associated Optic Neuritis - A Case Report and Literature Review

Background

Myelin oligodendrocyte glycoprotein (MOG)-IgG-associated optic neuritis (ON) is a new subset of demyelinating optic neuropathy.

Case Report

This study presents a case of a 49-year-old woman with MOG-IgG-positive ON, who reported to the ophthalmic emergency room with decreased visual acuity, retrobulbar pain and red color desaturation in her left eye. Abnormalities in the ophthalmological examination were: decreased Snellen's distance best-corrected visual acuity (DBCVA) to 0.04 in her left eye, slightly elevated optic nerve disc in the left eye confirmed by increased peripapillary retinal nerve fiber layer (RNFL) thickness in SD-OCT, abnormalities in pattern visual evoked potentials in both eyes. The preliminary diagnosis was demyelinating optic neuritis left for observation. However, two weeks after the first symptoms, treatment with intravenous methylprednisolone was initiated due to a decrease in DBCVA to no light perception. Intravenous steroids were followed by oral prednisone and later also by mycophenolate mofetil. The patient experienced slow but gradual improvement. One year after the occurrence of the initial symptoms, DBCVA was 0.5 in the left eye, however partial atrophy of the optic nerve developed, confirmed by macular ganglion cell layer (GCL) thickness and RNFL atrophy in SD-OCT, while visual pathway function improved.

Conclusion

All atypical cases of ON should be primarily considered for cell-based assays. MOG-IgG-positive ON usually responds well to steroid drugs and delaying immunosuppressive treatment may cause irreversible damage to the optic nerve.

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

BACKGROUND AND OBJECTIVES

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

METHODS

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

RESULTS

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

DISCUSSION

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

Validation of the International MOGAD Panel proposed criteria

With the increased clinical interest in myelin-oligodendrocyte glycoprotein-antibody-associated disease (MOGAD), the international MOGAD panel's proposed criteria were recently released. To evaluate its diagnostic performance, the criteria were applied to a single-center cohort. Among the enrolled 100 patients, 93 fulfilled the criteria throughout the median 24 months of follow-up. All 36 patients with a clear-positive MOG-immunoglobulin G (IgG) satisfied the supporting features, except one who did not undergo magnetic resonance imaging (MRI) scan at disease onset. The criteria also contributed significantly to the confirmation of MOGAD in 57 of 64 patients without clear-positive MOG-IgG. When limited to the first attack, 51 of 61 patients (84%) satisfied the criteria, 4 of whom were initially negative for MOG-IgG. These results support the diagnostic utility of the International MOGAD Panel criteria.

Neuromyelitis Optica: Pathogenesis Overlap with Other Autoimmune Diseases

PURPOSE OF REVIEW

Neuromyelitis optica (NMO) is an auto-immune disease essentially depicted by optic neuritis and transverse myelitis. Per se, NMO was initially believed to be a sub-type of multiple sclerosis with typical demyelinating cerebral lesions and optic nerve inflammation. More recently, corroborating lignes of evidence have strengthened the concept of the spectrum of diseases associated with NMO and more specifically with the role of anti-aquaporin-4 antibodies in the pathogenesis of disease.

RECENT FINDINGS

In this article, we review the recent pathogenic findings in NMO and more interestingly the newly discovered role of anti-aquaporin-4 antibodies as key players in triggering cerebral lesions. The concept of spectrum of diseases associated with NMO is also discussed. These recent findings have paved in the further understanding of the pathogenesis underlying NMO and new treatments are currently being developed targeting anti-aquaporin-4 antibodies.

Double hit - A case in point for dual seropositivity to AQP4 and MOG antibodies

AQP4-IgG NMOSD (anti-aquaporin-4 neuromyelitis optica spectrum disorder) and MOGAD (myelin oligodendrocyte glycoprotein antibody associated disease) are unique disorders among themselves, with rare reports of dual seropositivity being described. Evaluation with cell-based assays reduces the incidence of false positivity. The clinical features of these cases may either have a dominant phenotype or may evolve into one subsequently. We describe a young girl aged 18-year-old who presented with longitudinally extensive transverse myelitis and dual seropositivity to both AQP4 and MOG antibodies.

An update on optic neuritis

Optic neuritis (ON) is the most common cause of subacute optic neuropathy in young adults. Although most cases of optic neuritis (ON) are classified as typical, meaning idiopathic or associated with multiple sclerosis, there is a growing understanding of atypical forms of optic neuritis such as antibody mediated aquaporin-4 (AQP4)-IgG neuromyelitis optica spectrum disorder (NMOSD) and the recently described entity, myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD). Differentiating typical ON from atypical ON is important because they have different prognoses and treatments. Findings of atypical ON, including severe vision loss with poor recovery with steroids or steroid dependence, prominent optic disc edema, bilateral vision loss, and childhood or late adult onset, should prompt serologic testing for AQP4-IgG and MOG-IgG. Although the traditional division of typical and atypical ON can be helpful, it should be noted that there can be severe presentations of otherwise typical ON and mild presentations of atypical ON that blur these traditional lines. Rare causes of autoimmune optic neuropathies, such as glial fibrillary acidic protein (GFAP) and collapsin response-mediator protein 5 (CRMP5) autoimmunity also should be considered in patients with bilateral painless optic neuropathy associated with optic disc edema, especially if there are other accompanying suggestive neurologic symptoms/signs. Typical ON usually recovers well without treatment, though recovery may be expedited by steroids. Atypical ON is usually treated with intravenous steroids, and some forms, such as NMOSD, often require plasma exchange for acute attacks and long-term immunosuppressive therapy to prevent relapses. Since treatment is tailored to the cause of the ON, elucidating the etiology of the ON is of the utmost importance.

Clinical feature and disease outcome in patients with myelin oligodendrocyte glycoprotein antibody-associated disorder: a Chinese study

BACKGROUND

To identify factors associated with relapse risk and disability in myelin oligodendrocyte glycoprotein antibody-associated disorder (MOGAD).

METHOD

Between 2016 and 2021, 186 patients with MOGAD were included in the study. Factors associated with a relapsing course, annualised relapse rate (ARR), recurrent relapses under different maintenance treatments and unfavourable disability outcome were analysed.

RESULTS

MOGAD affects women (53.8%) slightly more often than men. After a median disease duration of 51.0 months, 60.2% (112/186) relapsed, with an overall ARR of 0.5. The ARR (0.6 vs 0.4, p=0.049), median Expanded Disability Status Scale (EDSS) score (1 (range 0-9.5) vs 1 (range 0-3.5), p=0.005) and Visual Functional System Score (VFSS) (0 (range 0-6) vs 0 (range 0-3), p=0.023) at last visit were higher in adults than in children, and time to first relapse was shorter in adults than in children (4.1 (range 1.0-111.0) vs 12.2 (range 1.3-266.8) months, p=0.001). Myelin oligodendrocyte glycoprotein antibody (MOG-ab) persistence over 1 year was associated with a relapsing course (OR 7.41, 95% CI 2.46 to 22.33, p=0.000), while timely maintenance therapy was associated with a lower ARR (p=0.008). More than four attacks (OR 4.86, 95% CI 1.65 to 14.28, p=0.004) and poor recovery from the first attack (OR 75.28, 95% CI 14.45 to 392.05, p=0.000) were associated with an unfavourable outcome (EDSS score ≥2 including VFSS ≥2).

CONCLUSIONS

The results underscored the importance of timely maintenance treatment to prevent further relapses, especially in adult patients with persistently positive MOG-ab and unsatisfactory recovery from the onset attack.

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD): current understanding and challenges

New diagnostic criteria for myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) have recently been proposed, distinguishing this syndrome from other inflammatory diseases of the central nervous system. Seropositivity status for MOG-IgG autoantibodies is important for diagnosing MOGAD, but only in the context of robust clinical characterization and cautious interpretation of neuroimaging. Over the last several years, access to cell-based assay (CBA) techniques has improved diagnostic accuracy, yet the positive predictive value of serum MOG-IgG values varies with the prevalence of MOGAD in any given patient population. For this reason, possible alternative diagnoses need to be considered, and low MOG-IgG titers need to be carefully weighted. In this review, cardinal clinical features of MOGAD are discussed. Key challenges to the current understanding of MOGAD are also highlighted, including uncertainty regarding the specificity and pathogenicity of MOG autoantibodies, the need to identify immunopathologic targets for future therapies, the quest to validate biomarkers that facilitate diagnosis and detect disease activity, and the importance of deciphering which patients with MOGAD require long-term immunotherapy.

Diagnosis of myelin oligodendrocyte glycoprotein antibody-associated disease: International MOGAD Panel proposed criteria

Serum antibodies directed against myelin oligodendrocyte glycoprotein (MOG) are found in patients with acquired CNS demyelinating syndromes that are distinct from multiple sclerosis and aquaporin-4-seropositive neuromyelitis optica spectrum disorder. Based on an extensive literature review and a structured consensus process, we propose diagnostic criteria for MOG antibody-associated disease (MOGAD) in which the presence of MOG-IgG is a core criterion. According to our proposed criteria, MOGAD is typically associated with acute disseminated encephalomyelitis, optic neuritis, or transverse myelitis, and is less commonly associated with cerebral cortical encephalitis, brainstem presentations, or cerebellar presentations. MOGAD can present as either a monophasic or relapsing disease course, and MOG-IgG cell-based assays are important for diagnostic accuracy. Diagnoses such as multiple sclerosis need to be excluded, but not all patients with multiple sclerosis should undergo screening for MOG-IgG. These proposed diagnostic criteria require validation but have the potential to improve identification of individuals with MOGAD, which is essential to define long-term clinical outcomes, refine inclusion criteria for clinical trials, and identify predictors of a relapsing versus a monophasic disease course.

Prognostic relevance of quantitative and longitudinal MOG antibody testing in patients with MOGAD: a multicentre retrospective study

BACKGROUND

IgG antibodies against myelin oligodendrocyte glycoprotein (MOG-IgG) define a subset of associated disorders (myelin oligodendrocyte glycoprotein associated disorders (MOGAD)) that can have a relapsing course. However, information on relapse predictors is scarce. The utility of retesting MOG-IgG over time and measuring their titres is uncertain. We aimed to evaluate the clinical relevance of longitudinal MOG-IgG titre measurement to predict relapses in patients with MOGAD.

METHODS

In this retrospective multicentre Italian cohort study, we recruited patients with MOGAD and available longitudinal samples (at least one >3 months after disease onset) and tested them with a live cell-based assay with endpoint titration (1:160 cut-off). Samples were classified as 'attack' (within 30 days since a disease attack (n=59, 17%)) and 'remission' (≥31 days after attack (n=295, 83%)).

RESULTS

We included 102 patients with MOGAD (57% adult and 43% paediatric) with a total of 354 samples (83% from remission and 17% from attack). Median titres were higher during attacks (1:1280 vs 1:640, p=0.001). Median onset titres did not correlate with attack-related disability, age or relapses. Remission titres were higher in relapsing patients (p=0.02). When considering the first remission sample available for each patient, titres >1:2560 were predictors of relapsing course in survival (log rank, p<0.001) and multivariate analysis (p<0.001, HR: 10.9, 95% CI 3.4 to 35.2). MOG-IgG seroconversion to negative was associated with a 95% relapse incidence rate reduction (incidence rate ratio: 0.05, p<0.001).

CONCLUSIONS

Persistent MOG-IgG positivity and high remission titres are associated with an increased relapse risk. Longitudinal MOG-IgG titres could be useful to stratify patients to be treated with long term immunosuppression.

Meta-analysis of the effectiveness of relapse prevention therapy for myelin-oligodendrocyte glycoprotein antibody-associated disease

BACKGROUND

Approximately 40% of adults and 30% of children with Myelin-oligodendrocyte glycoprotein antibody-associated disease (MOGAD) experience a relapsing course, but the optimal relapse prevention therapy remains unclear. A meta- analysis was conducted to investigate the efficacy of azathioprine (AZA), mycophenolate mofetil (MMF), rituximab (RTX), maintenance intravenous immunoglobulin (IVIG), and tocilizumab (TCZ) in prevention of attacks in MOGAD.

METHODS

English and Chinese-language articles published from January 2010 to May 2022 were searched in PubMed, Embase, Web of Science, Cochrane, Wanfang Data, China National Knowledge Infrastructure (CNKI), and China Science and Technology Journal Database (CQVIP). Studies with fewer than three cases were excluded. Meta-analysis of the relapse-free rate, the change of annualized relapse rate (ARR)and Expanded Disability Status Scale (EDSS) scores before and after treatment, and an age subgroup analysis was performed.

RESULTS

A total of 41 studies were included. Three were prospective cohort studies, one was an ambispective cohort study, and 37 were retrospective cohort studies or case series. Eleven, eighteen, eighteen, eight, and two studies were included in the meta-analysis for relapse-free probability after AZA, MMF, RTX, IVIG, and TCZ therapy, respectively. The proportions of patients without relapse after AZA, MMF, RTX, IVIG, and TCZ were 65% [95% confidence interval (CI):49%-82%]), 73% (95%CI:62%-84%), 66% (95%CI:55%-77%), 79% (95%CI:66%-91%), and 93% (95%CI:54%-100%), respectively. The relapse-free rate did not significantly differ between the children and adults treated with each medication. Six, nine, ten, and three studies were included in the meta-analysis for the change of ARR before and after AZA, MMF, RTX, and IVIG therapy, respectively. ARR was significantly decreased after AZA, MMF, RTX, and IVIG therapy with a mean reduction of 1.58 (95%CI: [-2.29--0.87]), 1.32 (95%CI: [-1.57--1.07]), 1.01 (95%CI: [-1.34--0.67]), and 1.84 (95%CI: [-2.66--1.02]), respectively. The change in ARR did not significantly differ between children and adults.

CONCLUSIONS

AZA, MMF, RTX, maintenance IVIG, and TCZ all reduce the risk of relapse in both pediatric and adult patients with MOGAD. The literatures included in the meta-analysis were mainly retrospective studies, so large randomized prospective clinical trials are needed to compare the efficacy of different treatments.

MOG antibody-associated encephalitis in adult: clinical phenotypes and outcomes

BACKGROUND

We investigated the clinical characteristics and outcomes of myelin oligodendrocyte glycoprotein (MOG) antibody-associated autoimmune encephalitis (MOGAE) in adult patients.

METHODS

From an institutional cohort, we analysed adult patients with MOGAE followed-up for more than 1 year. Disease severity was assessed using the modified Rankin scale (mRS) and Clinical Assessment Scale in Autoimmune Encephalitis scores. Immunotherapy profiles, outcomes and disease relapses were evaluated along with serial brain MRI data.

RESULTS

A total of 40 patients were enrolled and categorised into cortical encephalitis (18 patients), limbic encephalitis (LE, 5 patients) and acute disseminated encephalomyelitis (ADEM, 17 patients). 80.0% of patients achieved good clinical outcomes (mRS 0‒2) and 40.0% relapsed. The LE subtype was associated with an older onset age (p=0.004) and poor clinical outcomes (p=0.014) than the other subtypes but with a low rate of relapse (0.0%). 21/25 (84.0%) relapse attacks were associated with an absence or short (≤6 months) immunotherapy maintenance. On MRI, the development of either diffuse cerebral or medial temporal atrophy within the first 6 month was correlated with poor outcomes. MOG-antibody (MOG-Ab) was copresent with anti-N-methyl-D-aspartate receptor (NMDAR)-antibody in 13 patients, in whom atypical clinical presentation (cortical encephalitis or ADEM, p<0.001) and disease relapse (46.2% vs 0.0%, p<0.001) were more frequent compared with conventional NMDAR encephalitis without MOG-Ab.

CONCLUSIONS

Outcomes are different according to the three phenotypes in MOGAE. Short immunotherapy maintenance is associated with relapse, and brain atrophy was associated with poor outcomes. Patients with dual antibodies of NMDAR and MOG have a high relapse rate.

[Clinical features and modern diagnostic criteria of the disease associated with myelin oligodendrocyte glycoprotein antibody disease]

Demyelinating disease of the central nervous system associated with antibodies to myelin oligodendrocyte glycoprotein (MOGAD) has been proposed to be distinguished from neuromyelitis optica spectrum disorders (NMOSD) into a separate nosological form. The basis for the recognition of nosological independence was the presence of clinical features of this disease and the detection of a specific biomarker in the blood serum of patients - IgG class antibodies to MOG. The article summarizes the current data on the clinical and radiological phenotypes of MOGAD in children and adults and the features of the course of the disease. The requirements for the laboratory diagnosis of the disease and diagnostic criteria for MOGAD proposed by an international group of experts in 2023 are given.

[Typical and atypical optic neuritis]

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

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).

AQP4-MOG Double-Positive Neuromyelitis Optica Spectrum Disorder: Case Report with Central and Peripheral Nervous System Involvement and Review of Literature

(1) The co-occurrence of AQP4 and myelin oligodendrocyte glycoprotein (MOG) antibodies in patients with demyelinating disorders is extremely rare. In addition, a concomitant involvement of the peripheral nervous system (PNS) has been described either in association with AQP4 antibodies-positive neuromyelitis optica spectrum disorder (NMOSD), or MOG-associated disease. We report on a case of NMOSD with co-occurrence of AQP4 and MOG antibodies and concomitant central and peripheral nervous system involvement. We also reviewed available cases of AQP4-MOG double-positive patients. (2) Brain and spine MRI, cerebrospinal fluid studies, and electrophysiological test were performed. Serum AQP4 and MOG positivity was assessed with live cell-based assay. (3) A 62-year-old woman presented with recurrent optic neuritis, myelitis, and radiculitis, tested positive for AQP4 and MOG antibodies, and was treated successfully with rituximab. (4) Although few cases of AQP4-MOG double-positive patients were already described mostly affecting females with a concomitant spinal cord and optical nerve involvement, we describe the first case of double-positive NMOSD with the peculiar involvement of both central and peripheral nervous system.

Seroprevalence of anti-myelin oligodendrocyte glycoprotein antibodies in adults with myelitis

Although myelitis is the second most common presentation in adults with myelin oligodendrocyte glycoprotein (MOG) antibody‐associated disease (MOGAD), studies on MOG‐IgG seroprevalence in patients with myelitis episodes are sparse. Herein, we investigated MOG‐IgG seroprevalence in Korean adults who exhibited myelitis since 2017. Among 151 adults with acute myelitis, 11 (7.3%) tested positive for MOG‐IgG by the initial screening and 10 (6.6%) patients were finally diagnosed with MOGAD during the study period. This study is the first to provide data on MOG‐IgG seroprevalence in adults with myelitis and supports the clinical utility and importance of MOG‐IgG testing in myelitis episodes.

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.

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.

Clinical and Radiological Features of Myelin Oligodendrocyte Glycoprotein-Associated Myelitis in Adults

Antibodies against myelin oligodendrocyte glycoprotein (MOG-IgG) have recently been established as a biomarker for MOG-antibody-associated disease (MOGAD), which is a distinct demyelinating disease of the central nervous system. Among the diverse clinical phenotypes of MOGAD, myelitis is the second-most-common presentation in adults, followed by optic neuritis. While some features overlap, there are multiple reports of distinctive clinical and radiological features of MOG-IgG-associated myelitis, which are useful for differentiating MOGAD from both multiple sclerosis and neuromyelitis optica spectrum disorder. In this review we summarize the clinical and radiographic characteristics of MOG-IgG-associated myelitis with a particular focus on adult patients.

Serum MOG-IgG in children meeting multiple sclerosis diagnostic criteria

Background:

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is now recognized as distinct from multiple sclerosis (MS).

Objective:

To evaluate the importance of considering myelin oligodendrocyte glycoprotein (MOG)-immunoglobulin-G (IgG) serology when applying MS diagnostic criteria in children.

Methods:

Within a prospective cohort of children meeting MS criteria (median follow-up = 6 years, interquartile range (IQR) = 4–9), we measured MOG-IgG in serial archived serum obtained from presentation, and compared imaging and clinical features between seropositive and seronegative participants.

Results:

Of 65 children meeting MS criteria (median age = 14.0 years, IQR = 10.9–15.1), 12 (18%) had MOG-IgG at disease onset. Seropositive participants were younger, had brain magnetic resonance imaging (MRI) features atypical for MS, rarely had cerebrospinal fluid (CSF) oligoclonal bands (2/8, 25%), and accumulated fewer T2 lesions over time. On serial samples, 5/12 (42%) were persistently seropositive, 5/12 (42%) became seronegative, and 2/12 (17%) had fluctuating results. All 12 children experienced a disease course different from typical MS.

Conclusion:

While children with MOG-IgG can have clinical, CSF, and MRI features conforming to MS criteria, the presence of MOG-IgG is associated with atypical features and predicts a non-MS disease course. Given MOG-IgG seropositivity can wane over time, testing at first attack is of considerable importance for the diagnosis of MOGAD.

Clinical Profile and Treatment Outcome in MOGAD: A Single-Center Case-Series Study in Guiyang, China

Background

The clinical spectrum of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is expanding over time. However, the long-term management and prognosis of this disorder are still controversial. Therefore, this study aimed to report the clinical profiles and treatment outcomes of MOGAD in our center.

Methods

This was a single-center case-series study. Clinical and para-clinical data, along with treatment outcomes of patients with MOGAD were analyzed.

Results

A total of 27 patients were identified, of which 19 (70%) patients were women, and the median age at disease onset was 40 years (range 20–67). A total of 47 episodes were observed, with optic neuritis (53%) being the most frequent presentation and 60% of them were unilateral. Other presentations included rhombencephalitis (RE) (17%), limbic encephalitis (9%), simultaneous optic neuritis and myelitis (9%), acute disseminated encephalomyelitis (ADEM)-like presentation (6%), myelitis (4%), and ADEM (2%). One patient presenting with RE also met the diagnostic criteria of area postrema syndrome (APS). Another patient with RE presented with imaging characteristics of chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS). A total of 29 lumbar punctures were recorded, among which an elevated protein level was found in 34% of the samples, pleocytosis was found in 14% of the samples, and positive intrathecal oligoclonal bands were found in 19% of the patients. One patient was found to have anti-N-methyl-D-aspartate receptor antibodies both in his serum and cerebrospinal fluid. Intravenous methylprednisolone (IVMP) was administrated for 85% of the attacks while both IVMP and intravenous immunoglobulin were for 6% of the attacks. Moreover, nine patients received maintenance therapy. Among them, six patients were treated with mycophenolate mofetil, three patients were treated with prednisone, rituximab, and teriflunomide, respectively. The median follow-up period was 20 months (range 6–127). At follow-up, twelve (44%) patients experienced a relapsing course, and the median time to the first relapse was 9.5 months (range 2–120). The median Expanded Disability Status Scale score at nadir was 3.5 (range 2–8) and was 0 (range 0–3) at the last follow-up.

Conclusion

The clinical spectrum of MOGAD is heterogenous, wherein APS and CLIPPERS-form can occur. The long-term outcome of MOGAD seems benign. Further studies are warranted to determine the risk factors of relapse and identify the optimal steroid-sparing agents.

Association of Maintenance Intravenous Immunoglobulin With Prevention of Relapse in Adult Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease

Importance

Recent studies suggest that maintenance intravenous immunoglobulin (IVIG) may be an effective treatment to prevent relapses in myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD); however, most of these studies had pediatric cohorts, and few studies have evaluated IVIG in adult patients.

Objective

To determine the association of maintenance IVIG with the prevention of disease relapse in a large adult cohort of patients with MOGAD.

Design, Setting, and Participants

This was a retrospective cohort study conducted from January 1, 2010, to October 31, 2021. Patients were recruited from 14 hospitals in 9 countries and were included in the analysis if they (1) had a history of 1 or more central nervous system demyelinating attacks consistent with MOGAD, (2) had MOG-IgG seropositivity tested by cell-based assay, and (3) were age 18 years or older when starting IVIG treatment. These patients were retrospectively evaluated for a history of maintenance IVIG treatment.

Exposures

Maintenance IVIG.

Main Outcomes and Measures

Relapse rates while receiving maintenance IVIG compared with before initiation of therapy.

Results

Of the 876 adult patients initially identified with MOGAD, 59 (median [range] age, 36 [18-69] years; 33 women [56%]) were treated with maintenance IVIG. IVIG was initiated as first-line immunotherapy in 15 patients (25%) and as second-line therapy in 37 patients (63%) owing to failure of prior immunotherapy and in 7 patients (12%) owing to intolerance to prior immunotherapy. The median (range) annualized relapse rate before IVIG treatment was 1.4 (0-6.1), compared with a median (range) annualized relapse rate while receiving IVIG of 0 (0-3) (t108 = 7.14; P < .001). Twenty patients (34%) had at least 1 relapse while receiving IVIG with a median (range) time to first relapse of 1 (0.03-4.8) years, and 17 patients (29%) were treated with concomitant maintenance immunotherapy. Only 5 of 29 patients (17%) who received 1 g/kg of IVIG every 4 weeks or more experienced disease relapse compared with 15 of 30 patients (50%) treated with lower or less frequent dosing (hazard ratio, 3.31; 95% CI, 1.19-9.09; P = .02). At final follow-up, 52 patients (88%) were still receiving maintenance IVIG with a median (range) duration of 1.7 (0.5-9.9) years of therapy. Seven of 59 patients (12%) discontinued IVIG therapy: 4 (57%) for inefficacy, 2 (29%) for adverse effects, and 1 (14%) for a trial not receiving therapy after a period of disease inactivity.

Conclusions and Relevance

Results of this retrospective, multicenter, cohort study of adult patients with MOGAD suggest that maintenance IVIG was associated with a reduction in disease relapse. Less frequent and lower dosing of IVIG may be associated with treatment failure. Future prospective randomized clinical trials are warranted to confirm these findings.

Magnetic Resonance Imaging of Autoimmune Demyelinating Diseases as a Diagnostic Challenge for Radiologists: Report of Two Cases and Literature Review

The magnetic resonance characteristics of autoimmune demyelinating diseases are complex and represent a challenge for the radiologist. In this study we presented two different cases of detected autoimmune demyelinating diseases: one case of acute disseminated encephalomyelitis and one case of neuromyelitis optica, respectively. Expected and unexpected findings of magnetic resonance imaging examination for autoimmune demyelinating diseases were reported in order to provide a valuable approach for diagnosis. In particular, we highlight, review and discuss the presence of several uncommon imaging findings which could lead to a misinterpretation. The integration of magnetic resonance imaging findings with clinical and laboratory data is necessary to provide a valuable diagnosis.

Serum and Cerebrospinal Fluid Biomarkers in Neuromyelitis Optica Spectrum Disorder and Myelin Oligodendrocyte Glycoprotein Associated Disease

The term neuromyelitis optica spectrum disorder (NMOSD) describes a group of clinical-MRI syndromes characterized by longitudinally extensive transverse myelitis, optic neuritis, brainstem dysfunction and/or, less commonly, encephalopathy. About 80% of patients harbor antibodies directed against the water channel aquaporin-4 (AQP4-IgG), expressed on astrocytes, which was found to be both a biomarker and a pathogenic cause of NMOSD. More recently, antibodies against myelin oligodendrocyte glycoprotein (MOG-IgG), have been found to be a biomarker of a different entity, termed MOG antibody-associated disease (MOGAD), which has overlapping, but different pathogenesis, clinical features, treatment response, and prognosis when compared to AQP4-IgG-positive NMOSD. Despite important refinements in the accuracy of AQP4-IgG and MOG-IgG testing assays, a small proportion of patients with NMOSD still remain negative for both antibodies and are called “seronegative” NMOSD. Whilst major advances have been made in the diagnosis and treatment of these conditions, biomarkers that could help predict the risk of relapses, disease activity, and prognosis are still lacking. In this context, a number of serum and/or cerebrospinal fluid biomarkers are emerging as potentially useful in clinical practice for diagnostic and treatment purposes. These include antibody titers, cytokine profiles, complement factors, and markers of neuronal (e.g., neurofilament light chain) or astroglial (e.g., glial fibrillary acidic protein) damage. The aim of this review is to summarize current evidence regarding the role of emerging diagnostic and prognostic biomarkers in patients with NMOSD and MOGAD.

Uncommon inflammatory/immune-related myelopathies

The differential diagnosis for immune-mediated myelopathies is broad. Although clinical manifestations overlap, certain presentations are suggestive of a particular myelopathy etiology. Spine MRI lesion characteristics including the length and location, and the pattern of gadolinium enhancement, help narrow the differential diagnosis and exclude an extrinsic compressive cause. The discovery of specific antibodies that serve as biomarkers of myelitis such as aquaporin-4-IgG and myelin-oligodendrocyte -glycoprotein-IgG (MOG-IgG), has improved our understanding of myelitis pathophysiology and facilitated diagnosis. In this review we will focus on the pathophysiology, clinical presentation, imaging findings and treatment and outcomes of uncommon immune-mediated myelopathies.

Myelin Oligodendrocyte Glycoprotein Antibody-Associated Optic Neuritis-A Review

ABSTRACT

Our understanding of demyelinating optic neuritis has substantially evolved over the past 2 decades. With advancements in serological testing, antibodies against myelin oligodendrocyte glycoprotein (MOG) have been recently discovered in a distinct subset of demyelinating neuroinflammatory disease. Although MOG-immunoglobulin G (IgG)-associated disorder (MOGAD) has previously been seen as a component of neuromyelitis optica spectrum disorder (NMOSD), evidence increasingly suggests that it should be distinguished as a separate condition. The distinction of MOGAD from aquaporin-4 IgG NMOSD is imperative as treatment plans need to be tailored to its unique disease course and prognosis. The purpose of this review is to explore the nature and outcomes of MOGAD optic neuritis to help guide acute and long-term immunosuppressive treatment decisions.

Clinical and neuroimaging findings in MOGAD-MRI and OCT

Myelin oligodendrocyte glycoprotein antibody-associated disorders (MOGAD) are rare in both children and adults, and have been recently suggested to be an autoimmune neuroinflammatory group of disorders that are different from aquaporin-4 autoantibody-associated neuromyelitis optica spectrum disorder and from classic multiple sclerosis. In-vivo imaging of the MOGAD patient central nervous system has shown some distinguishing features when evaluating magnetic resonance imaging of the brain, spinal cord and optic nerves, as well as retinal imaging using optical coherence tomography. In this review, we discuss key clinical and neuroimaging characteristics of paediatric and adult MOGAD. We describe how these imaging techniques may be used to study this group of disorders and discuss how image analysis methods have led to recent insights for consideration in future studies.

Evidence for and against subclinical disease activity and progressive disease in MOG antibody disease and neuromyelitis optica spectrum disorder

Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) and aquaporin-4 IgG seropositive neuromyelitis optica spectrum disorder (AQP4-IgG+ NMOSD) are generally considered to be relapsing disorders, without clinical progression or subclinical disease activity outside of clinical relapses, in contrast to multiple sclerosis (MS). With advances in the diagnosis and treatment of these conditions, prolonged periods of remission without relapses can be achieved, and the question of whether progressive disease courses can occur has re-emerged. In this review, we focus on studies exploring evidence for and against relapse-independent clinical progression and/or subclinical disease activity in patients with MOGAD and AQP4-IgG+ NMOSD.

Overlapping syndrome mimicking infectious meningoencephalitis in a patient with MOG and GFAP IgG

Background

Central nervous system overlapping autoimmune syndromes are uncommon, especially with the coexistence of MOG-IgG and GFAP-IgG.

Case presentation

A 23-year-old woman presented with transient convulsions, a loss of consciousness, persistent fever, headache, and vomiting. Cerebrospinal fluid (CSF) analysis revealed elevated cellularity, and magnetic resonance imaging (MRI) showed diffuse leptomeningeal enhancement. She had fever and headache with antiviral and antibiotic treatment for 2 weeks, and she had empirical anti-tuberculosis treatment and oral prednisolone therapy. She was followed for 3 months after presentation with improved symptoms and normal CSF analysis. A 3-month follow-up MRI showed asymmetric lesions in the cerebellum, corona radiata, and white matter with enhancement. The anti-tuberculosis treatment was continued, and steroid therapy was discontinued. After she stopped taking prednisolone, an interrupted headache gradually appeared. MRI at 4 months after presentation revealed a partial reduction in lesions but enlarged areas in the left cerebellum and right parietal white matter and a new lesion in the region of the right ependyma with linear enhancement. Her CSF was positive for anti-myelin oligodendrocyte glycoprotein (MOG) and anti-glial fibrillary acidic protein (GFAP) antibodies using a transfected cell-based assay. She was diagnosed with overlapping syndrome of MOG‑IgG‑associated disease and GFAP astrocytopathy. She received steroid pulse therapy (methylprednisolone, 1 g for 5 days), followed by a gradual tapering of oral prednisolone and the addition of an immunosuppressant (tacrolimus, 3 mg per day). Six months after the initial presentation, she had no symptoms. An MRI showed that the lesions had diminished, and no enhancement was found.

Conclusions

We report a case that was positive for double antibodies, which was initially misdiagnosed as infectious meningoencephalitis. This case broadens the clinical and phenotypic presentation of the overlapping syndrome spectrum.

Comparisons of clinical phenotype, radiological and laboratory features, and therapy of neuromyelitis optica spectrum disorder by regions: update and challenges

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory demyelinating disease of the central nervous system (CNS) associated with autoantibody (ab) to aquaporin-4 (AQP4). There is obvious variation between regions and countries in the epidemiology, clinical features and management in NMOSD. Based on published population-based observation and cohort studies, the different clinical pattern of NMOSD has been seen in several geographical regions and some of these patients with NMOSD-like features do not fully meet the current diagnostic criteria, which is needed to consider the value of recently revised diagnostic criteria. At present, all treatments applied in NMOSD have made great progress, however, these treatments failed in AQP4 ab negative and refractory patients. Therefore, it is necessary to turn into an innovative idea and to open a new era of NMOSD treatment to develop novel and diverse targets and effective therapeutic drugs in NMOSD and to conduct the trails in large clinical samples and case-control studies to confirm their therapeutic effects on NMOSD in the future, which still remain a challenge.

Frequency of myelin oligodendrocyte glycoprotein antibodies in a large cohort of neurological patients

Background

Myelin oligodendrocyte glycoprotein (MOG) antibody disease (MOG-AD) is recognized as a distinct nosological entity. IgG antibodies against MOG (MOG-Ab) overlap with neuromyelitis optica spectrum disorders (NMOSD) phenotype in adults. However, an increasing number of clinical phenotypes have been reported to be associated with MOG-Ab.

Objective

To investigate the seroprevalence of MOG-Ab under consideration of demographics, disease entities and time course in a large cohort of unselected neurological patients.

Methods

Blood samples of 2.107 consecutive adult neurologic patients admitted to our department between 2016-2017 were tested for MOG-Ab using a cell-based assay. MOG-Ab persistence was analyzed in follow-up samples. External validation was performed in two independent laboratories.

Results

We found MOG-Ab in 25 of 2.107 (1.2%) patients. High antibody ratios were mostly associated with NMOSD and MOG-AD phenotype (5/25). Low ratios occurred in a wide range of neurological diseases, predominantly in other demyelinating CNS diseases (5/25) and stroke (6/25). MOG-Ab persistence over time was not confined to NMOSD and MOG-AD phenotype.

Conclusion

The present study demonstrates the occurrence of MOG-Ab in a wide range of neurological diseases. Only high MOG-Ab ratios were associated with a defined clinical phenotype, but low MOG-Ab ratios were not. The diagnostic value of low MOG-Ab is thus highly limited.

A nation-wide survey of Japanese pediatric MOG antibody-associated diseases

OBJECTIVE

To elucidate the clinical characteristics of Japanese pediatric patients with acquired demyelinating diseases (ADS), positive for myelin oligodendrocyte glycoprotein antibody (MOG-IgG), we conducted a nation-wide survey.

METHODS

Information about pediatric patients under 18 years old with ADS was solicited with surveys sent to 323 facilities. In an initial survey, we asked whether the center had any patients with ADS, and the MOG-IgG serostatus of the patients. In a follow-up survey, we requested more precise information on patients with ADS.

RESULTS

Initial survey: 263 replies providing information on 175 patients were received. MOG-IgG were examined in 78 patients and 54 of those (69%) were positive for MOG-IgG. Follow-up survey: The characteristic involvement was optic neuritis, with visual disturbance and optic pain as characteristic symptoms. The relapse rate was 44% in patients positive for MOG-IgG, which was higher than that in seronegative patients (38%). For acute phase treatments, corticosteroid (CS), plasma exchange, and intravenous immunoglobulin (IVIG) were useful. To prevent relapse, CS, intermittent IVIG, immunosuppressants, and monoclonal antibodies were useful, but the efficacies of disease modifying drugs were uncertain. Sequelae such as visual disturbance, cognitive impairment, motor dysfunction, and epilepsy were observed in 11% of patients with MOG-IgG.

CONCLUSIONS

MOG antibody-associated diseases were found to be common among pediatric ADS patients. Since a variety of sequelae were observed in these patients, it is important to identify the appropriate treatment to ensure the best outcome. The presence of the MOG autoantibody should be taken into consideration as part of the diagnostic criteria for pediatric ADS.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Immune-Mediated Myelopathies: A Review of Etiologies, Diagnostic Approach, and Therapeutic Management

Myelopathy is a broad term used to describe a heterogeneous group of disorders that affects the spinal cord; the focus of this article will be a subgroup of these disorders with an autoimmune and inflammatory-based pathology. Symptoms typically develop over hours or days and then worsen over a matter of days to weeks, but sometimes can have a more insidious or subacute presentation, which can make the diagnosis more puzzling. Despite relatively low incidence rates, almost a third of affected patients are left with severely disabling symptoms. Prompt recognition of the underlying etiology is essential so that a specific targeted therapy can be implemented for optimal outcomes. The authors discuss a systematic approach to immune-mediated myelopathies, with a focus on the unique characteristics of each that may aid in diagnosis.

Acute retrobulbar optic neuritis with anti-myelin oligodendrocyte glycoprotein antibody-associated disease complicated with microscopic polyangiitis: A case report

RATIONALE

Anti-myelin oligodendrocyte protein antibody-associated disease (MOGAD) is a new disease entity with various clinical phenotypes. MOGAD often present with recurrent optic neuritis (ON), and it can also develop as a compartment of neuromyelitis optica spectrum disorder (NMOSD). Moreover, multiple autoantibodies such as an anti-myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) had been reported in the serum of patients with NMOSD.

PATIENT CONCERNS

We report an 86-year-old woman with a 2-year history of microscopic polyangiitis (MPA). The patient had a rapid loss of vision in her left eye. No abnormal findings were observed on her left fundus, and she tested negative for MPO-ANCA upon admission. However, anti-MOG antibodies were observed in the patient's serum and cerebrospinal fluid.

DIAGNOSIS

A diagnosis of MOGAD complicated with MPA was made.

INTERVENTIONS

The patient received twice steroid pulse therapy and oral azathioprine as maintenance therapy.

OUTCOMES

Her vision rapidly recovered, and no subsequent relapse was observed during the 8-month observation period.

CONCLUSION

To the best of our knowledge, this is the first case of MOGAD complicated with MPA, and steroid pulse therapy and azathioprine therapy were effective for ON caused by MOGAD.

New Therapeutic Landscape in Neuromyelitis Optica

Purpose of review

This review discusses the current treatment trends and emerging therapeutic landscape for patients with neuromyelitis optica spectrum disorder (NMOSD).

Recent findings

Conventional immune suppressive therapies, such as B cell depletion, have been used for long-term treatment. However, the availability of recent FDA-approved and investigational drugs has made therapeutic choices for NMOSD more complex.

Summary

Recent randomized clinical trials have shown that eculizumab, inebilizumab, and satralizumab are efficacious therapies for AQP4 seropositive NMOSD. These therapies may not have the same benefit in patients with seronegative NMOSD, including MOG-associated disease, and further investigation is required in this population. Reliable biomarkers to guide therapy decisions are urgently needed. There is a plethora of promising investigational therapies currently in the pipeline with exciting and novel mechanisms of action.

[Treatment of antibody-mediated encephalomyelitis : Strategies for the treatment of neuromyelitis optica spectrum disorder and myelin oligodendrocyte glycoprotein antibody-associated disease]

BACKGROUND

Antibody-mediated encephalomyelitis, such as neuromyelitis optica spectrum disorder (NMOSD), myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), and glial fibrillary acidic protein (GFAP) antibody-associated astrocytopathy belong to a group of newly described autoimmune diseases.

AIM

Presentation of the treatment of antibody-mediated encephalomyelitis with a focus on NMOSD and MOGAD.

METHODS

Selective literature search in PubMed taking the consultation version of the S2k guidelines of the German Society of Neurology (DGN) on the diagnosis and treatment of multiple sclerosis (MS), NMOSD and MOG IgG-associated diseases into account.

RESULTS

Acute relapses are treated with high-dose steroid pulse therapy or apheresis therapy (plasma exchange or immunoadsorption). It is crucial to start treatment as quickly as possible and apheresis therapy can also be used as first-line treatment under certain conditions. For prophylactic immunotherapy, steroids, classical immunosuppressants and monoclonal antibodies with specific mechanisms of action are used. Eculizumab, inebilizumab and satralizumab are the first drugs approved for NMOSD. Symptomatic treatment and neurorehabilitation are important complementary measures.

CONCLUSION

Treatment of antibody-mediated encephalomyelitis differs from treatment of multiple sclerosis and requires specific measures.

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.

Longitudinal Evaluation of Serum MOG-IgG and AQP4-IgG Antibodies in NMOSD by a Semiquantitative Ratiometric Method

Background and purpose: Immunoadsorption (IA) is an antibody-depleting therapy used to treat neuromyelitis optica spectrum disorder (NMOSD) associated to antiaquaporin 4 (anti-AQP4-IgG) and antimyelin oligodendrocyte glycoprotein (anti-MOG-IgG) serum autoantibodies. Our aim was to evaluate longitudinal changes of serum MOG-IgG and AQP4-IgG antibody titer and to correlate it with the clinical status.

Methods: Autoantibody titer and clinical features of two MOG-IgG+/AQP4-IgG– and two AQP4-IgG+/MOG-IgG– patients with NMOSD were collected at baseline (T0), after 6 IA courses (T1), and then 2 weeks (T2) and 6 months after treatment (T3). A fluorescent ratiometric assay was used for a quantitative detection of MOG and AQP4 antibodies, based on HEK-293 cells transfected with the full-length hMOG fused to GFP or h-AQP4-M23 isoform fused to m-cherry, respectively. We defined the antibody titer as MOG quantitative ratio (MOGqr) and AQP4 quantitative ratio (AQP4qr).

Results: In Case 1, the MOGqr dropped from 0.98 at T0 to 0.14 at T3, and in Case 2, it decreased from 0.96 at T0 to undetectable at T3. In Case3, the AQP4qr remained high: 0.90 at T0 and 0.92 at T3. In Case 4, the AQP4qr decreased from 0.50 at T0 to undetectable at T3. Complete recovery was found in Cases 1, 2, and 4.

Conclusions: Semiquantitative ratiometric method accurately detects even slight variation of MOG-IgG and AQP4-IgG titer, suggesting it may be useful to monitor the antibody titer during the disease course and maintenance immunotherapy.

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

Optic neuritis (ON) is the most common cause of acute optic neuropathy in patients younger than 50 years of age and is most frequently idiopathic or associated with multiple sclerosis. However, the discovery of aquaporin-4 immunoglobulin G (IgG) and myelin oligodendrocyte glycoprotein (MOG)-IgG as biomarkers for two separate central nervous system inflammatory demyelinating diseases has revealed that neuromyelitis optica spectrum disorder (NMSOD) and MOG-IgG-associated disease (MOGAD) are responsible for clinically distinct subsets of ON. NMOSD-ON and MOGAD-ON both demonstrate tendencies for bilateral optic nerve involvement and often exhibit a relapsing course with the potential for devastating long-term visual outcomes. Early and accurate diagnosis is therefore essential. This review will summarize the current understanding of the clinical spectra of NMOSD and MOGAD, the radiographic and serological findings which support their diagnoses, and the current evidence behind various acute and long-term therapeutic strategies for ON related to these conditions. A particular emphasis is placed on a number of recent multi-centre randomized placebo-controlled trials, which provide the first level I evidence for long-term treatment of NMOSD.

Myelin oligodendrocyte glycoprotein antibody-associated disorders: clinical spectrum, diagnostic evaluation, and treatment options

Inflammatory or immune-mediated demyelinating central nervous system (CNS) syndromes include a broad spectrum of clinical phenotype and different overlapping diseases. Antibodies against myelin oligodendrocyte glycoprotein (MOG-Ab) have been found in some cases of these demyelinating diseases, particularly in children. MOG-Ab is associated with a wider clinical phenotype not limited to neuromyelitis optica spectrum disorder, with most patients presenting with optic neuritis, acute disseminated encephalomyelitis (ADEM) or ADEM-like encephalitis with brain demyelinating lesions, and/or myelitis. Using specific cell-based assays, MOG-Ab is becoming a potential biomarker of inflammatory demyelinating disorders of the CNS. A humoral immune reaction against MOG was recently found in monophasic diseases and recurrent/multiphasic clinical progression, particularly in pediatric patients. This review summarizes the data regarding MOG-Ab as an impending biological marker for discriminating between these diverse demyelinating CNS diseases and discusses recent developments, clinical applications, and findings regarding the immunopathogenesis of MOG-Ab-associated disorders.

Clinical spectrum, treatment and outcome of myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease in children: a tertiary care experience

Anti-myelin oligodendrocyte glycoprotein antibodies have been associated with a wide range of clinical presentations including monophasic and relapsing disease courses. Lack of a definitive marker for predicting further relapses and the final diagnoses complicates the clinical follow-up and treatment decisions for patients with the first episode. This study retrospectively analyzed the clinical spectrum, treatment protocols and outcome of nine children with MOG antibody-associated demyelinating disease. Diagnoses at first presentation were acute disseminated encephalomyelitis (ADEM) in six cases (67%), optic neuritis in two cases (22%), and clinically isolated syndrome in one case (11%). The disease remained monophasic in five (56%) cases. All cases with a monophasic disease course were negative for anti-MOG antibody titers in the third month. The initial diagnosis of all relapsing cases was ADEM. Three of the four cases with a relapsing disease course were available for anti-MOG antibody testing at the third month and all were positive, however, antibody titers at the sixth month were inconsistent. Cases with a relapsing disease course had no further attacks after monthly intravenous immunoglobulin treatment. Relapsing disease course is not rare in childhood MOG-antibody associated demyelinating disease. Monthly IVIG treatment may be a good alternative for the long-term treatment of relapsing cases with a low side effect profile. Anti-MOG antibody serostatus at remission periods should be interpreted cautiously. Further studies are needed to better understand and predict the clinical course of pediatric patients with MOG-antibody associated diseases.