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The blood–brain barrier, which is formed by tightly interconnected microvascular endothelial cells, separates the brain from the peripheral circulation. Together with other central nervous system-resident cell types, including pericytes and astrocytes, the blood–brain barrier forms the neurovascular unit. Upon neuroinflammation, this barrier becomes leaky, allowing molecules and cells to enter the brain and to potentially harm the tissue of the central nervous system. Despite the significance of animal models in research, they may not always adequately reflect human pathophysiology. Therefore, human models are needed. This review will provide an overview of the blood–brain barrier in terms of both health and disease. It will describe all key elements of the in vitro models and will explore how different compositions can be utilized to effectively model a variety of neuroinflammatory conditions. Furthermore, it will explore the existing types of models that are used in basic research to study the respective pathologies thus far. [ABSTRACT FROM AUTHOR]

Although much is already known about the exaggerated host immune response in severe COVID-19 disease, little is known about the relationship between this dysregulated immune response and the extent of brain injury. This scientific commentary refers to 'Brain injury in COVID-19 is associated with dysregulated innate and adaptive immune responses' by Needham I et al. i (https://doi.org/10.1093/brain/awac321). [Extracted from the article]

Interestingly, no patient in our cohort suffered from a relapse after time of first seroconversion, although fluctuating MOG-IgG titres with increase after a period of low or even negative MOG-IgG titres were reported in selected patients. Likewise, onset serum MOG-IgG titres, despite being important for the diagnosis of MOGAD, do not predict recovery or relapse.[1],[7] In most patients MOG-IgG titres decline with time, but may also remain positive in other patients for years. [Extracted from the article]

Anti-myelin oligodendrocyte glycoprotein (MOG) antibodies (MOG-Abs) were first detected by immunoblot and enzyme-linked immunosorbent assay nearly 30 years ago, but their association with multiple sclerosis (MS) was not specific. Use of cell-based assays with native MOG as the substrate enabled identification of a group of MOG-Ab-positive patients with demyelinating phenotypes. Initially, MOG-Abs were reported in children with acute disseminated encephalomyelitis (ADEM). Further studies identified MOG-Abs in adults and children with ADEM, seizures, encephalitis, anti-aquaporin-4-antibody (AQP4-Ab)-seronegative neuromyelitis optica spectrum disorder (NMOSD) and related syndromes (optic neuritis, myelitis and brainstem encephalitis), but rarely in MS. This shift in our understanding of the diagnostic assays has re-invigorated the examination of MOG-Abs and their role in autoimmune and demyelinating disorders of the CNS. The clinical phenotypes, disease courses and responses to treatment that are associated with MOG-Abs are currently being defined. MOG-Ab-associated disease is different to AQP4-Ab-positive NMOSD and MS. This Review provides an overview of the current knowledge of MOG, the metrics of MOG-Ab assays and the clinical associations identified. We collate the data on antibody pathogenicity and the mechanisms that are thought to underlie this. We also highlight differences between MOG-Ab-associated disease, NMOSD and MS, and describe our current understanding on how best to treat MOG-Ab-associated disease. [ABSTRACT FROM AUTHOR]

We have recently demonstrated the safety and tolerability of a novel therapeutic regimen employing autologous blood cells chemically coupled with seven myelin peptides to induce antigen-specific tolerance in MS (ETIMS study). The aim of the current study was an extended safety analysis to assess the effect of the ETIMS approach on antibodies to common autoantigens, the myelin peptides used and common recall antigens. None of the patients showed induction of autoantibody responses. One patient had a measurable myelin peptide-specific response at baseline, which was reduced after treatment. Total immunoglobulins and recall antibody responses showed no significant change. [ABSTRACT FROM AUTHOR]

The recent detection of aquaporin-4 (AQP4) and myelin oligodendrocyte glycoprotein (MOG) autoantibodies in acquired inflammatory demyelinating diseases, such as neuromyelitis optica, or acute disseminated encephalomyelitis, and multiple sclerosis, in children strongly indicates that B-cell-dependent mechanisms contribute to the pathogenesis. This review aims to give an overview of the role of autoantibodies in inflammatory demyelinating pediatric diseases, with a focus on antibodies to AQP4 and MOG. [ABSTRACT FROM AUTHOR]

Myelin oligodendrocyte glycoprotein (MOG) has been identified as a target of demyelinating autoantibodies in animal models of inflammatory demyelinating diseases of the CNS, such as multiple sclerosis (MS). Numerous studies have aimed to establish a role for MOG antibodies in patients with MS, although the results have been controversial. Cell-based immunoassays using MOG expressed in mammalian cells have demonstrated the presence of high-titre MOG antibodies in paediatric patients with acute disseminated encephalomyelitis, MS. aquaporin-4-seronegative neuromyelitis optica, or isolated optic neuritis or transverse myelitis, but only rarely in adults with these disorders. These studies indicate that MOG antibodies could be associated with a broad spectrum of acquired human CNS demyelinating diseases. This Review article discusses the current I terature on MOG antibodies, their potential clinical relevance, and their role in the pathogenesis of MOG antibody-associated demyelinating disorders. [ABSTRACT FROM AUTHOR]

The role of microglial activation in multiple system atrophy (MSA) was investigated in a transgenic mouse model featuring oligodendroglial alpha-synuclein inclusions and loss of midbrain dopaminergic neurons by means of histopathology and morphometric analysis. Our findings demonstrate early progressive microglial activation in substantia nigra pars compacta (SNc) associated with increased expression of iNOS and correlating with dopaminergic neuronal loss. Suppression of microglial activation by early long-term minocycline treatment protected dopaminergic SNc neurons. The results suggest that oligodendroglial overexpression of alpha-synuclein may induce neuroinflammation related to nitrosive stress which is likely to contribute to neurodegeneration in MSA. Further, we detected increased toll-like receptor 4 immunoreactivity in both transgenic mice and MSA brains indicating a possible signaling pathway in MSA which needs to be further studied as a candidate target for neuroprotective interventions. [ABSTRACT FROM AUTHOR]

Abstract: Multiple sclerosis (MS), the most important human inflammatory demyelinating disease of the central nervous system, is characterized by heterogenous genetic backgrounds and immunopathogenetic subtypes, various clinical disease courses, and inhomogeneous and unpredictable therapeutic effects. Because of this heterogeneity, subtyping of our MS patients by genetical, clinical, neuroradiological, and neuroimmunological parameters will be an urgent need in the near future. Therefore the importance of identifying biological markers for MS has evolved over the past years. Evidence for a possible role of antibodies as biological markers for MS comes from several studies indicating that intrathecal antibody production and the dominance of B-cells are associated with a more progressive disease course. This review summarizes the current status and potential applicability of antibodies as biological markers for the diagnosis, classification, disease activity and prediction of clinical courses in MS. Antibodies (and other molecules) serving as biomarkers will help to establish a differential therapeutic concept in MS, which should allow to treat individuals selectively according to their pathogenetic subtype and disease status. [Copyright &y& Elsevier]

Abstract: Multiple sclerosis (MS), the most important human inflammatory demyelinating disease of the central nervous system, is characterized by various clinical disease courses, inhomogeneous and unpredictable therapeutic effects, heterogenous genetic backgrounds and immunopathogenetic subtypes as demonstrated by neuropathology. Because of this heterogeneity of MS, a subtyping of our patients by genetical, clinical, neuroradiological, and neuroimmunological parameters will be necessary in the future. Therefore the importance of identifying biological markers for MS has evolved over the past years. Evidence for a possible role of antibodies as biological markers for MS comes from several studies indicating that intrathecal antibody production and the dominance of B cells are associated with a more progressive disease course. In this review we will give an overview on the current status and potential applicability of antibodies as biological markers for the diagnosis, classification, disease activity and prediction of clinical courses in MS. We will therefore summarize the findings on autoantibodies to myelin and nonmyelin antigens and on viral antigens in MS. We believe that antibodies serving as biomarkers will help to establish a differential therapeutic concept in MS, which will allow to treat individuals selectively according to their pathogenetic subtype and disease status. [Copyright &y& Elsevier]

The first international workshop on "Biomarkers in Multiple Sclerosis" was organized by B. Bielekova, R. Hohlfeld, R. Martin and U. Utz from April 14–16, 2004, in Washington, DC. The workshop intended to discuss the current status and potential applicability of biological markers for the understanding of the pathogenesis, diagnosis, and therapy of multiple sclerosis. The present review summarizes the presentation on the potential role of antibodies as biomarkers for diagnosis, disease activity, classification and prediction of clinical courses in multiple sclerosis. [ABSTRACT FROM AUTHOR]

Abstract: Only few reports are available on the epitope specificity of anti-myelin oligodendrocyte glycoprotein (MOG) antibodies in multiple sclerosis (MS). In the present study we provide a precise characterization of the epitope specificity of serum antibodies directed against the extracellular domain of MOG, including IgG, IgM and IgA immunoglobulin isotypes in 28 relapsing remitting MS patients and report that linear epitopes amino-acid (aa) 37–48 and aa42–53 are immunodominant. Recently experienced relapses intensified the anti-MOG peptide antibody response. Immunomodulatory treatment with interferon-beta or glatiramer-acetate had no major impact on the anti-MOG peptide immunoreactivity after 1year of therapy. [Copyright &y& Elsevier]

α-Synuclein represents the major constituent of oligodendroglial cytoplasmic inclusions, the hallmark lesion of multiple system atrophy (MSA), a progressive disorder that is associated with selective degenerative cell loss in basal ganglia, cerebellum, brainstem, and spinal cord. The role of abnormal α-synuclein aggregation in oligodendroglial cells is still obscure, in particular, whether α-synuclein might impair oligodendroglial and, secondarily, neuronal integrity of those cells in the diseased brain. In an attempt to answer some of these questions, we have developed an 'in vitro model of MSA' by expressing the wild-type or C-terminally truncated form of α-synuclein in glial cell cultures. With this simplified system, we have demonstrated that α-synuclein significantly affects the survival of glia and its vulnerability to environmental stress, which might represent a major step in the pathogenesis of MSA. © 2005 Movement Disorder Society [ABSTRACT FROM AUTHOR]

Nerve growth factor (NGF) is an important factor regulating survival in development and during regenerative or neuroinflammatory processes. The aim of this study was to investigate whether brain capillary endothelial cells (BCEC) respond to NGF and whether pro-inflammatory substances induce the secretion of NGF in these cells. Cells were incubated with the growth factors NGF or vascular endothelial growth factor or endothelial cell growth factor, and proliferation was observed by incorporation of 5-bromo-2′-deoxy-uridine. NGF-secretion was measured by ELISA and expression of the NGF-receptors trkA and p75NTR by Western blot. Proliferation of BCEC was enhanced by exogenous NGF (1–100 ng/ml.). BCEC expressed NGF receptors in vivo (P3, P10, P20, adult) and displayed secretion of endogenous NGF (∼20 pg/ml) into the medium. Treatment of BCEC with the proinflammatory cytokine interleukin-1β+lipopolysaccharide enhanced expression of p75NTR and the secretion of NGF (∼35 pg/ml). The effects of NGF were blocked by anti-NGF antibodies (5 μg/ml). In summary, NGF shows proliferative activity in BCEC, and NGF is secreted after inflammation. Therefore, the NGF pathway can modulate BCEC and may influence blood–brain barrier functions. [Copyright &y& Elsevier]

Nogo-A is a protein associated with central nervous system (CNS) myelin thought to impair regenerative responses and to suppress sprouting and plastic changes of synaptic terminals. In this study, we report that serum IgM autoantibodies to the recombinant large N-terminal inhibitory domain of Nogo-A are a frequent finding in multiple sclerosis (MS) and acute inflammatory (IND) and non-inflammatory neurological diseases (OND), but not in neurodegenerative diseases (ND), systemic inflammatory disease and healthy controls. Furthermore, we demonstrate intrathecal production of anti-Nogo-A antibodies measured by increased IgG indices. Intrathecal anti-Nogo antibodies were significantly more frequent in patients with relapsing–remitting as compared to chronic progressive (CP) MS. We also found a highly significant negative correlation of these antibody responses with age indicating that they are more frequent in younger patients. We finally demonstrate that human anti-Nogo-A antibodies recognize native Nogo-A in brain extracts, oligodendrocytes and cells expressing human Nogo-A. [Copyright &y& Elsevier]

We investigated the association of the antibody response to myelin oligodendrocyte glycoprotein (MOG) and myelin basic protein (MBP) with human leukocyte antigen (HLA) class II alleles in 41 patients with sporadic multiple sclerosis (MS) and 12 multiplex MS families. We found significantly increased antibody response to MOG and MBP in MS patients without any difference to asymptomatic relatives. HLA DRB1*04 was associated with IgM reactivity to MOG in MS patients, and DRB1*15 and DRB5 with anti-MOG IgA among asymptomatic relatives. We conclude that antibody responses to MOG and MBP depend on familial background. Moreover, the humoral immune reactivity against MOG is partially under control of certain HLA class II alleles. [Copyright &y& Elsevier]

The systemic inflammatory response following acute ischaemic stroke remains incompletely understood. We characterised the circulating inflammatory profile in 173 acute ischaemic stroke patients by measuring 65 cytokines and chemokines in plasma. Participants were grouped based on their inflammatory response, determined by high-sensitivity C-reactive protein levels in the acute phase. We compared stroke patients’ profiles with 42 people experiencing spontaneous cervical artery dissection without stroke. Furthermore, variations in cytokine levels among stroke aetiologies were analysed. Follow-up samples were collected in a subgroup of ischaemic stroke patients at three and twelve months. Ischaemic stroke patients had elevated plasma levels of HGF and SDF-1α, and lower IL-4 levels, compared to spontaneous cervical artery dissection patients without stroke. Aetiology-subgroup analysis revealed reduced levels of nine cytokines/chemokines (HGF, SDF-1α, IL-2R, CD30, TNF-RII, IL-16, MIF, APRIL, SCF), and elevated levels of IL-4 and MIP-1β, in spontaneous cervical artery dissection (with or without ischaemic stroke as levels were comparable between both groups) compared to other aetiologies. The majority of cytokine/chemokine levels remained stable across the study period. Our research indicates that stroke due to large artery atherosclerosis, cardioembolism, and small vessel occlusion triggers a stronger inflammatory response than spontaneous cervical artery dissection. [ABSTRACT FROM AUTHOR]

In absence of existing studies, to describe changes in balance and mobility, following specific task-oriented training (TOT), its combination with talocrural manual therapy (MT-TOT) or no intervention, in chronic stroke patients. To explore the feasibility of a full-scale randomised controlled trial (RCT) based on criteria of recruitment, retention and adherence rates, adverse events, falls and acceptability of the intervention. Using an assessor-blinded pilot RCT, 36 stroke patients were allocated to either MT-TOT, TOT, or controls. Supervised interventions were performed 45 min, 2×/weekly, for 4 weeks, and home-based practice 20 min, 4x/weekly for 4 weeks. Qualitative interviews evaluated intervention acceptability. Outcomes of balance, mobility, ankle dorsiflexion range of motion (ROM), falls and health-related quality of life (HRQoL) were assessed at baseline, post-intervention and 4-week follow-up. Preliminary efficacy of MT-TOT and TOT was shown in improving balance (effect size 0.714), walking speed (0.683), mobility (0.265), dual-tasking mobility (0.595), falls (0.037), active and passive talocrural ROM (0.603; 0.751) and activities and social participation related HRQoL domains (0.332–0.784) in stroke patients. The feasibility of a larger RCT was confirmed. Specific MT-TOT and TOT appeared effective and are feasible in stroke patients. A larger RCT is needed to validate the results.Trial Registration: German Clinical Trials Register, DRKS00023068. Registered on 21.09.2020, A specific goal- and task-oriented training involving timed mobility and dynamic balance activities based on the demands of daily life, of high intensity and progressed in difficulty according to predefined criteria is feasible in patients after stroke. In this mixed methods pilot study patients indicated high acceptability of task-oriented training with and without ankle mobilisations, with their descriptions being in line with the Theoretical Framework of Acceptability. Specific task-oriented training and its combination with talocrural joint manual therapy improved balance, mobility, talocrural dorsiflexion range of motion and some domains of health-related quality of life in people after stroke. [ABSTRACT FROM AUTHOR]

To investigate determinants of willingness to adopt telerehabilitation, willingness of technology use, core affect regarding using telerehabilitation, and digital competencies in rehabilitation professionals in Austria and Germany before and during the COVID-19 pandemic. A cross-sectional paper-based and online survey was conducted before and during COVID-19, respectively, with three cohorts of rehabilitation professionals. Outcomes were the willingness to adopt telerehabilitation evaluated using the extended Unified Theory of Acceptance and Use of Technology; willingness of technology use using the short scale for assessing the willingness of technology use; digital competencies and core affect using the Digital Competence Framework and semantic differential, respectively. Multivariate ordinal regression analysis was performed to determine predictors. Included were 603 rehabilitation professionals. Analysis revealed differences between Austria and Germany and before and during the pandemic for most outcomes. German residency, the pandemic, and a higher educational level were most important predictors of higher willingness to adopt telerehabilitation, willingness of technology use, digital competencies, and positive core affect. The pandemic increased most aspects of willingness to adopt telerehabilitation, willingness of technology use, digital competencies, and positive core affect. Results confirm that rehabilitation professionals with higher degrees are more prone to adopt innovations in healthcare.Registration: German Clinical Trials Register (DRKS00021464) The willingness to adopt telerehabilitation is associated with external factors increasing the need for alternative rehabilitation delivery, such as COVID-19, and with financial facilitators, such as reimbursement. As the willingness to adopt telerehabilitation is higher among speech and language therapists and dietitians, efforts are necessary to enhance its use in physiotherapists and occupational therapists. As a higher willingness to adopt telerehabilitation was observed in younger rehabilitation professionals and those with higher education, increasing the importance of telerehabilitation in education curricula and further knowledge transfer into practice for those already working in the field seems necessary. [ABSTRACT FROM AUTHOR]

Background: Self-efficacy concerns individuals' beliefs in their capability to exercise control in specific situations and complete tasks successfully. In people with multiple sclerosis (PwMS), self-efficacy has been associated with physical activity levels and quality of life. As a validated German language self-efficacy scale for PwMS is missing the aims of this study were to translate the Unidimensional Self-Efficacy Scale for Multiple Sclerosis (USE-MS) into German, establish face and content validity and cultural adaptation of the German version for PwMS in Austria. A further aim was to validate the German USE-MS (USE-MS-G) in PwMS.Methods: Permission to translate and validate the USE-MS was received from the scale developers. Following guidelines for translation and validation of questionnaires and applying Bandura's concept of self-efficacy, the USE-MS was forward-backward translated with content and face validity established. Cultural adaptation for Austria was performed using cognitive patient interviews. Reliability was assessed using Cronbach's alpha, Person separation index and Lin's concordance correlation coefficient. Rasch analysis was employed to assess construct validity. Comparison was made to scales for resilience, general self-efficacy, anxiety and depression, multiple sclerosis fatigue and health-related quality of life. Data were also pooled with an historic English dataset to compare the English and German language versions.Results: The translation and cultural adaptation were successfully performed in the adaptation process of the USE-MS-G. Pretesting was conducted in 30 PwMS, the validation of the final USE-MS-G involved 309 PwMS with minimal to severe disability. The USE-MS-G was found to be valid against the Rasch model when fitting scale data using a bifactor solution of two super-items. It was shown to be unidimensional, free from differential item functioning and well targeted to the study population. Excellent convergent and known-groups validity, internal consistency, person separation reliability and test-retest reliability were shown for the USE-MS-G. Pooling of the English and German datasets confirmed invariance of item difficulties between languages.Conclusion: The USE-MS-G is a robust, valid and reliable scale to assess self-efficacy in PwMS and can generate interval level data on an equivalent metric to the UK version.Trial Registration: ISRCTN Registry; ISRCTN14843579 ; prospectively registered on 02. 01. 2019. [ABSTRACT FROM AUTHOR]

Aim: Pre-clinical studies in models of multiple sclerosis and other inflammatory disorders suggest that high-salt diet may induce activation of the immune system and potentiate inflammation. However, high-salt diet constitutes a common non-pharmacological intervention to treat autonomic problems in synucleinopathies such as Parkinson's disease and multiple system atrophy. Since neuroinflammation plays an important pathogenic role in these neurodegenerative disorders, we asked here whether high-salt diet may aggravate the disease phenotype in a transgenic model of multiple system atrophy.Methods: Nine-month-old PLP-hαSyn and matched wildtype mice received normal or high-salt diet for a period of 3 months. Behavioral, histological, and molecular analyses were performed to evaluate the effect of high-salt diet on motor decline, neuroinflammation, neurodegeneration, and α-synuclein accumulation in these mice.Results: Brain subregion-specific molecular and histological analyses showed no deleterious effects of high-salt diet on the level of microglial activation. Moreover, neuroinflammation-related cytokines and chemokines, T cell recruitment or astrogliosis were unaffected by high-salt diet exposure. Behavioral testing showed no effect of diet on motor decline. High-salt diet was not related to the deterioration of neurodegeneration or α-synuclein accumulation in PLP-hαSyn mice.Conclusions: Here, we demonstrate that high-salt diet does not aggravate neuroinflammation and neurodegeneration in PLP-hαSyn mice. Our findings discard a deleterious pro-neuroinflammatory effect of high-salt diet in multiple system atrophy. [ABSTRACT FROM AUTHOR]

This commentary is on the original article by Hacohen et al. on pages 836–841 of this issue. [ABSTRACT FROM AUTHOR]

This article presents a letter to the editor in response to "Antimyelin antibodies in clinically isolated syndromes correlate with inflammation in MRI and CSF," by J. Kuhle, R. Lindberg and A. Regeniter et al in the January 25, 2007 issue.

Background and purpose: Serum neurofilament light chain (sNfL) is a promising biomarker of neuroaxonal damage in persons with multiple sclerosis (pwMS). In cross‐sectional studies, sNfL has been associated with disease activity and brain magnetic resonance imaging (MRI) changes; however, it is still unclear to what extent in particular high sNfL levels impact on subsequent disease evolution. Methods: sNfL was quantified by an ultrasensitive single molecule array (Simoa) in 199 pwMS (median age = 34.2 years, 64.3% female) and 49 controls. All pwMS underwent 3‐T MRI to assess global and compartmental normalized brain volumes, T2‐lesion load, and cortical mean thickness. Follow‐up data and serum samples were available in 144 pwMS (median follow‐up time = 3.8 years). Linear and binary logistic models were used to estimate the independent contribution of sNfL for changes in MRI and Expanded Disability Status Scale (EDSS). Age‐corrected sNfL z‐scores from a normative database of healthy controls were used for sensitivity analyses. Results: High sNfL levels at baseline were associated with atrophy measures of the whole brain (standardized beta coefficient βj = −0.352, p < 0.001), white matter (βj = −0.229, p = 0.007), thalamus (βj = −0.372, p = 0.004), and putamen (βj = −1.687, p = 0.012). pwMS with high levels of sNfL at baseline and follow‐up had a greater risk of EDSS worsening (p = 0.007). Conclusions: Already single time point elevation of sNfL has a distinct effect on brain volume changes over a short‐term period, and repeated high levels of sNfL indicate accumulating physical disability. Serial assessment of sNfL may provide added value in the clinical management of pwMS. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Omicron variants are still the dominant SARS-CoV-2 viruses worldwide, therefore determining the level of protection from infection and severe disease is essential. Here, we investigated humoral and cellular immunity of individuals immunized by ChAdOx1, BNT162b2 and mRNA-1273 and our results show that IgG and neutralization titers wane over time. However, strongest neutralization against Omicron BA.1 and T cell responses were detected in ChAdOx1 vaccinees six months after the second dose, while no long lasting neutralization was shown against BA.2 in any cohort. Crucially, our investigation revealed that immunity against variants of concern is heterogenic and dependent on the immunization status. [ABSTRACT FROM AUTHOR]

Background: Overlap syndromes of anti-NMDA receptor encephalitis and MOG-mediated demyelination have been reported. In this case we provide a long-term longitudinal follow-up of clinical and imaging characteristics as well as of antibody dynamics.Case Presentation: We report a 32-year-old male patient who presented with psychosis, decreased consciousness and movement disorders and was tested positive for anti-NMDA receptor antibodies. Forty-four months after symptom onset and diagnosis of autoimmune encephalitis, he suffered from relapse. At this time, the patient developed anti-MOG and anti-Caspr2 antibodies. Treatment with plasmapheresis, steroids and rituximab eventually led to substantial clinical and radiological improvement. Anti-Caspr2 antibodies persisted, anti-NMDA receptor antibodies decreased, while anti-MOG antibodies turned negative again.Conclusion: We provide long-term longitudinal follow-up of a patient with anti-NMDA receptor encephalitis who developed triple antibody positivity at the time of relapse. Antibody dynamics were associated with clinical disease course. [ABSTRACT FROM AUTHOR]

The role of autoantibodies in multiple sclerosis (MS) has been enigmatic since the first description, many decades ago, of intrathecal immunoglobulin production in people with this condition. Some studies have indicated that MS pathology is heterogeneous, with an antibody-associated subtype - characterized by B cells (in varying quantities), antibodies and complement - existing alongside other subtypes with different pathologies. However, subsequent evidence suggested that some cases originally diagnosed as MS with autoantibody-mediated demyelination were more likely to be neuromyelitis optica spectrum disorder or myelin oligodendrocyte glycoprotein antibody-associated disease. These findings raise the important question of whether an autoantibody-mediated MS subtype exists and whether pathogenic MS-associated autoantibodies remain to be identified. Potential roles of autoantibodies in MS could range from specific antibodies defining the disease to a non-disease-specific amplification of cellular immune responses and other pathophysiological processes. In this Perspective, we review studies that have attempted to identify MS-associated autoantibodies and provide our opinions on their possible roles in the pathophysiology of MS. [ABSTRACT FROM AUTHOR]

A response by Thomas Berger and Markus Reindl to a letter to the editor about their article "Antimyelin Antibodies As a Predictor of Clinically Definite Multiple Sclerosis After a First Demyelinating Event," published in a 2003 issue of the "New England Journal of Medicine" is presented.

Background: Natalizumab (NTZ) is an established treatment for highly active, relapsing-remitting multiple sclerosis. In the context of rare progressive multifocal leukoencephalopathy and extended interval dosing as a treatment option, biomarkers for treatment monitoring are required. Natalizumab serum concentration (NTZ SC) and soluble vascular cell adhesion molecule 1 (sVCAM-1) concentration were shown to change on treatment with NTZ. We aimed to investigate whether NTZ SC and sVCAM-1 could be suitable pharmacodynamic markers and whether they could predict disease activity on NTZ, improving the concept of personalized multiple sclerosis treatment. Methods: In a retrospective study at the Medical University of Innsbruck, Austria, we identified patients treated with NTZ and chose samples longitudinally collected during routine follow-ups for the measurement of NTZ SC and sVCAM-1 by an enzyme-linked immunosorbent assay. We correlated these with clinical and demographic variables and clinical outcomes. Furthermore, we analyzed the stability of NTZ SC and sVCAM-1 during treatment. Results: One hundred and thirty-seven patients were included. We found a strong negative correlation between NTZ SC and sVCAM-1. Both showed significant associations with body mass index, infusion interval, sample age, and anti-drug-antibodies. Natalizumab serum concentration was reduced in extended interval dosing, but not sVCAM-1. Only sVCAM-1 showed a weak association with relapses during treatment, while there was no association with disease progression. Both NTZ SC and sVCAM-1 showed a wide inter-individual distribution while levels in single patients were stable on treatment. Conclusions: Soluble vascular cell adhesion molecule 1 is a suitable pharmacodynamic marker during treatment with NTZ, which is significantly reduced already after the first dose, remains stable in individual patients even on extended interval dosing, and strongly correlates with NTZ SC. Because of the high inter-individual range, absolute levels of sVCAM-1 and NTZ SC are difficult to introduce as treatment monitoring biomarkers in order to predict disease activity in single patients. [ABSTRACT FROM AUTHOR]

Objective: To assess the diagnostic and prognostic potential of serum neurofilament light chain (sNfL) in children with first acquired demyelinating syndrome (ADS). Methods: We selected 129 children with first ADS including 19 children with myelin oligodendrocyte glycoprotein (MOG)-antibody associated disease (MOGAD), 36 MOG/AQP4-seronegative ADS, and 74 with multiple sclerosis (MS) from the BIOMARKER study cohort. All children had a complete set of clinical, radiological, laboratory data and serum for NfL measurement using a highly sensitive digital ELISA (SIMOA). A control group of 35 children with non-inflammatory neurological diseases was included. sNfL levels were compared across patient groups according to clinical, laboratory, neuroradiological features and outcome after 2 years. Results: sNfL levels were significantly increased in MOGAD, seronegative ADS and MS compared to controls (p -value < 0.001), in particular in children with an acute disseminated encephalomyelitis (ADEM)-like magnetic resonance imaging (MRI) pattern (p < 0.001) or longitudinally extensive myelitis (p < 0.01). In pediatric MS, elevated sNfL levels were significantly associated with higher numbers of cerebral (p < 0.001) and presence of spinal (p < 0.05) MRI lesions at baseline and predicted a higher number of relapses (p < 0.05). Conclusion: sNfL levels are significantly elevated in all three studied pediatric ADS subtypes indicating neuroaxonal injury. In pediatric MS high levels of sNfL are associated with risk factors for disease progression. [ABSTRACT FROM AUTHOR]

Although there is no evidence for a role of anti-MOG antibodies in adult MS, no information on B lymphocytes with MOG-committed BCR is available. We report here on the frequency of anti-MOG B cells forming rosettes with polystyrene beads (BBR) covalently bound to the extracellular domain of rhMOG in 38 relapsing-remitting patients (RRMS) and 50 healthy individuals (HI). We show a substantial proportion of circulating anti-MOG-BBR in both RRMS and HI. Strikingly, MOG-specific B cells frequencies were lower in MS than in HI. Anti-MOG antibodies measured by a cell-based assay were not different between MS patients and controls, suggesting a specific alteration of anti-MOG B cells in MS. Although anti-MOG-BBR were higher in CNS fluid than in blood, no difference was observed between MS and controls. Lower frequency of MOG-BBR in MS was not explained by an increased apoptosis, but a trend for lower proliferative capacity was noted. Despite an efficient B cell transmigration across brain derived endothelial cells, total and anti-MOG B cells transmigration was similar between MS and HI. The striking alteration in MOG-specific B cells, independent of anti-MOG antibody titers, challenges our view on the role of MOG-specific B cells in MS. [ABSTRACT FROM AUTHOR]

Autoantibodies targeting conformationally intact myelin oligodendrocyte glycoprotein (MOG) are found in different inflammatory diseases of the CNS, but their antigenic epitopes have not been mapped. We expressed mutants of MOG on human HeLa cells and analyzed sera from 111 patients (104 children, 7 adults) who recognized cell-bound human MOG, but had different diseases, including acute disseminated encephalomyelitis (ADEM), one episode of transverse myelitis or optic neuritis, multiple sclerosis (MS), anti-aquaporin-4 (AQP4)-negative neuromyelitis optica (NMO), and chronic relapsing inflammatory optic neuritis (CRION). We obtained insight into the recognition of epitopes in 98 patients. All epitopes identified were located at loops connecting the β strands of MOG. The most frequently recognized MOG epitope was revealed by the P42S mutation positioned in the CC'-loop. Overall, we distinguished seven epitope patterns, including the one mainly recognized by mouse mAbs. In half of the patients, the anti-MOG response was directed to a single epitope. The epitope specificity was not linked to certain disease entities. Longitudinal analysis of 11 patients for up to 5 y indicated constant epitope recognition without evidence for intramolecular epitope spreading. Patients who rapidly lost their anti-MOG IgG still generated a long-lasting IgG response to vaccines, indicating that their loss of anti-MOG reactivity did not reflect a general lack of capacity for long-standing IgG responses. The majority of human anti-MOG Abs did not recognize rodent MOG, which has implications for animal studies. Our findings might assist in future detection of potential mimotopes and pave the way to Ag-specific depletion. [ABSTRACT FROM AUTHOR]

Myelin oligodendrocyte glycoprotein (MOG)‐antibody (Ab)–associated diseases (MOGADs) account for a substantial proportion of pediatric and adult patients who present with acquired demyelinating disorders. Its pathogenesis and optimal therapy are incompletely understood. We profiled systemic complement activation in adult and pediatric patients with MOGAD compared with patients with relapse‐onset multiple sclerosis, patients with neuromyelitis optica spectrum disorder, and pediatric control and adult healthy donors. Proteins indicative of systemic classical and alternative complement activation were substantially increased in patients with MOGAD compared to control groups. Elevated levels were detected in both adult and pediatric cases and across all clinical syndromes. Complement inhibition should be explored for its therapeutic merit in patients with MOGAD. ANN NEUROL 2021;90:976–982 [ABSTRACT FROM AUTHOR]

Abstract: Nerve growth factor (NGF), a member of the neurotrophin family, is responsible for the maintenance and survival of cholinergic neurons in the basal forebrain. The degeneration of cholinergic neurons and reduced acetycholine levels are hallmarks of Alzheimer's disease (AD) as well as associated with learning and memory deficits. Thus far, NGF has proven the most potent neuroprotective molecule against cholinergic neurodegeneration. However, delivery of this factor into the brain remains difficult. Recent studies have begun to elucidate the potential use of monocytes as vehicles for therapeutic delivery into the brain. In this study, we employed different transfection and transduction methods to generate NGF-secreting primary rat monocytes. Specifically, we compared five methods for generating NGF-secreting monocytes: (1) cationic lipid-mediated transfection (Effectene and FuGene), (2) classical electroporation, (3) nucleofection, (4) protein delivery (Bioporter) and (5) lentiviral vectors. Here, we report that classical transfection methods (lipid-mediated transfection, electroporation, nucleofection) are inefficient tools for proper gene transfer into primary rat monocytes. We demonstrate that lentiviral infection and Bioporter can successfully transduce/load primary rat monocytes and produce effective NGF secretion. Furthermore, our results indicate that NGF is bioactive and that Bioporter-loaded monocytes do not appear to exhibit any functional disruptions (i.e. in their ability to differentiate and phagocytose beta-amyloid). Taken together, our results show that primary monocytes can be effectively loaded or transduced with NGF and provides information on the most effective method for generating NGF-secreting primary rat monocytes. This study also provides a basis for further development of primary monocytes as therapeutic delivery vehicles to the diseased AD brain. [Copyright &y& Elsevier]

Myelin-associated inhibition of axonal regrowth after injury is considered one important factor that contributes to regeneration failure in the adult central nervous system (CNS). Blocking strategies targeting this pathway have been successfully applied in several nerve injury models, including experimental autoimmune encephalomyelitis (EAE), suggesting myelin-associated inhibitors (MAIs) and functionally related molecules as targets to enhance regeneration in multiple sclerosis. NgR1 and NgR2 were identified as interaction partners for the myelin proteins Nogo-A, MAG and OMgp and are probably mediating their growth-inhibitory effects on axons, although the in vivo relevance of this pathway is currently under debate. Recently, alternative functions of MAIs and NgRs in the regulation of immune cell migration and T cell differentiation have been described. Whether and to what extent NgR1 and NgR2 are contributing to Nogo and MAGrelated inhibition of neuroregeneration or immunomodulation during EAE is currently unknown. Here we show that genetic deletion of both receptors does not promote functional recovery during EAE and that NgR1 and NgR2-mediated signals play a minor role in the development of CNS inflammation. Induction of EAE in Ngr1/2-double mutant mice resulted in indifferent disease course and tissue damage when compared to WT controls. Further, the development of encephalitogenic CD4+ Th1 and Th17 responses was unchanged. However, we observed a slightly increased leukocyte infiltration into the CNS in the absence of NgR1 and NgR2, indicating that NgRs might be involved in the regulation of immune cell migration in the CNS. Our study demonstrates the urgent need for a more detailed knowledge on the multifunctional roles of ligands and receptors involved in CNS regeneration failure. [ABSTRACT FROM AUTHOR]

The Parkinson variant of multiple system atrophy (MSA-P) is a distinct atypical parkinsonian disorder with a loss of dopaminergic neurons comparable to that found in Parkinson's disease (PD). The additional loss of striatopallidal projections is thought to account for levodopa unresponsiveness in MSA-P. Whereas histological features of MSA-P have been successfully reproduced in the double lesion rat model, loss of levodopa responsiveness has so far not been demonstrated. In the current study, 6-hydroxydopamine (6-OHDA) induced unilateral lesions of the substantia nigra produced a marked contralateral forelimb stepping deficit, which improved significantly after challenge with levodopa (P < 0.001). This response was abolished by the subsequent striatal quinolinic acid (QA) lesion. In the cylinder test, the marked asymmetry observed after 6-OHDA lesioning was reversed by levodopa to baseline levels. After QA, cylinder test performance under levodopa failed to reach baseline (P = 0.001) or 6-OHDA + levodopa (P = 0.002) levels. Nigral cell loss (90% +/- 5%) correlated with both stepping test (r = 0.608; P = 0.008) and cylinder test results (r = 0.656; P = 0.005). Lesion extent of the dorsal striatum correlated significantly with the loss of levodopa response (r = 0.593; P = 0.01) in the stepping test. These findings contribute further to the behavioral characterization of the double lesion rat model of MSA, improving its value in the evaluation of future neurorestorative strategies. [ABSTRACT FROM AUTHOR]

Multiple system atrophy (MSA) is a fatal neurodegenerative disorder presenting with autonomic failure and motor impairment, primarily comprising l-dopa-resistant parkinsonism but occasionally involving cerebellar ataxia. These features result from progressive multisystem neuronal loss that is associated with oligodendroglial α-synuclein inclusions. The growing number of animal models for MSA reflects the search for a preclinical test-bed for elucidating MSA pathogenesis and for developing novel therapeutic interventions. Here, the currently available MSA animal models will be reviewed and leads for future research will be identified. [Copyright &y& Elsevier]

We studied 38 patients with malaria tropica over a period of 5 days during antiparasitic therapy. Serum or plasma levels of interleukin (IL) 1β, IL-6, IL-10, tumour necrosis factor-α (TNF-α), the soluble vascular adhesion molecule (sVCAM) and the soluble intracellular adhesion molecule (sICAM) were determined by enzyme-linked immunosorbent assay. Protein C and antithrombin III activity were analysed by chromogenic tests and protein S activity by a clotting test. Antithrombin III, protein C and protein S activity was significantly lower in patients with severe malaria and displayed a highly significant increase in activity over the time of evaluation. Levels of sVCAM and sICAM were increased for the whole study period, but no significant differences were found between severe and mild malaria cases. Serum IL-1β, IL-6 and IL-10 levels were significantly higher in patients with severe malaria, whereas no significant differences were found for TNF-α. IL-6 and IL-10 decreased significantly over 5 days during schizontocidal therapy. Our data show an impairment of the coagulation system which correlates with pro-inflammatory cytokines and therefore with the severity of the disease. [ABSTRACT FROM AUTHOR]

Background: To investigate age-related severity, patterns of retinal structural damage, and functional visual recovery in pediatric and adult cohorts of myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) optic neuritis (ON).Methods: All MOGAD patients from the 5 participating centers were included. Patients with initial manifestation <18 years were included in the pediatric (MOGADped) cohort and patients with ≥18 years in the adult (MOGADadult) cohort. For patients with MOGAD ON, examinations at least ≥6 months after ON onset were included in the analyses. Using spectral domain optical coherence tomography (SD-OCT), we acquired peripapillary retinal nerve fiber layer thickness (pRNFL) and volumes of combined ganglion cell and inner plexiform layer (GCIPL). High- and 2.5% low-contrast visual acuity (HCVA, LCVA) and visual-evoked potentials (VEP) were obtained.Results: Twenty MOGADped (10.3±3.7 years, 30 MOGAD ON eyes) and 39 MOGADadult (34.9±11.6 years, 42 MOGAD ON eyes) patients were included. The average number of ON episodes per ON eye was similar in both groups (1.8±1.3 and 2.0±1.7). In both pediatric and adult MOGAD, ON led to pronounced neuroaxonal retinal atrophy (pRNFL: 63.1±18.7 and 64.3±22.9 μm; GCIPL: 0.42±0.09 and 0.44±0.13 mm3, respectively) and moderate delay of the VEP latencies (117.9±10.7 and 118.0±14.5 ms). In contrast, visual acuity was substantially better in children (HCVA: 51.4±9.3 vs. 35.0±20.6 raw letters, p=0.001; LCVA: 22.8±14.6 vs. 13.5±16.4, p=0.028). Complete visual recovery (HCVA-logMAR 0.0) occurred in 73.3% of MOGADped and 31% MOGADadults ON eyes, while 3.3% and 31% demonstrated moderate to severe (logMAR > 0.5) visual impairment. Independent of retinal atrophy, age at ON onset significantly correlated with visual outcome.Conclusion: Pediatric MOGAD ON showed better visual recovery than adult MOGAD ON despite profound and almost identical neuroaxonal retinal atrophy. Age-related cortical neuroplasticity may account for the substantial discrepancy between structural changes and functional outcomes. [ABSTRACT FROM AUTHOR]

Scarce pathological brain evaluations confirmed the distinct entity of MOG-Abs-associated disorders (MOGAD), characterised by relative axonal sparing, perivenous, subpial, cortical and confluent primary demyelination, reactive gliosis, and inflammatory infiltrates predominantly constituted by granulocytes, macrophages, and CD4 + T cells [[2], [6]]. Spinal cord MRI showed multiple short T2-hyperintense lesions involving the spinal cord from the cranio-cervical junction to T12 and a central tumefactive lesion extending longitudinally from T9 to the conus (Fig. Antibodies to myelin oligodendrocyte glycoprotein (MOG-Abs) define a distinct entity of inflammatory CNS diseases, commonly presenting with subacute optic neuritis and/or myelitis in adults and encephalomyelitis in children [[5]]. We herein report the first autoptic findings of brain, spinal cord, nerve roots, and leptomeninges of a patient with MOG-Abs positivity in CSF only. [Extracted from the article]

Background: Neuromyelitis optica spectrum disorder (NMOSD) is a frequently disabling neuroinflammatory syndrome with a relapsing course. Blood-based disease severity and prognostic biomarkers for NMOSD are a yet unmet clinical need. Here, we evaluated serum glial fibrillary acidic protein (sGFAP) and neurofilament light (sNfL) as disease severity and prognostic biomarkers in patients with aquaporin-4 immunoglobulin (Ig)G positive (AQP4-IgG+) NMOSD.Methods: sGFAP and sNfL were determined by single-molecule array technology in a prospective cohort of 33 AQP4-IgG+ patients with NMOSD, 32 of which were in clinical remission at study baseline. Sixteen myelin oligodendrocyte glycoprotein IgG-positive (MOG-IgG+) patients and 38 healthy persons were included as controls. Attacks were recorded in all AQP4-IgG+ patients over a median observation period of 4.25 years.Results: In patients with AQP4-IgG+ NMOSD, median sGFAP (109.2 pg/ml) was non-significantly higher than in MOG-IgG+ patients (81.1 pg/ml; p = 0.83) and healthy controls (67.7 pg/ml; p = 0.07); sNfL did not substantially differ between groups. Yet, in AQP4-IgG+, but not MOG-IgG+ patients, higher sGFAP was associated with worse clinical disability scores, including the Expanded Disability Status Scale (EDSS, standardized effect size = 1.30, p = 0.007) and Multiple Sclerosis Functional Composite (MSFC, standardized effect size = - 1.28, p = 0.01). While in AQP4-IgG+, but not MOG-IgG+ patients, baseline sGFAP and sNfL were positively associated (standardized effect size = 2.24, p = 0.001), higher sNfL was only non-significantly associated with worse EDSS (standardized effect size = 1.09, p = 0.15) and MSFC (standardized effect size = - 1.75, p = 0.06) in patients with AQP4-IgG+ NMOSD. Patients with AQP4-IgG+ NMOSD with sGFAP > 90 pg/ml at baseline had a shorter time to a future attack than those with sGFAP ≤ 90 pg/ml (adjusted hazard ratio [95% confidence interval] = 11.6 [1.3-105.6], p = 0.03). In contrast, baseline sNfL levels above the 75th age adjusted percentile were not associated with a shorter time to a future attack in patients with AQP4-IgG+ NMOSD.Conclusion: These findings suggest a potential role for sGFAP as biomarker for disease severity and future disease activity in patients with AQP4-IgG+ NMOSD in phases of clinical remission. [ABSTRACT FROM AUTHOR]

Keywords: Myelin oligodendrocyte glycoprotein (MOG); Antibodies; Optic neuritis; Ovarian teratoma EN Myelin oligodendrocyte glycoprotein (MOG) Antibodies Optic neuritis Ovarian teratoma 127 131 5 01/07/21 20210101 NES 210101 Electronic supplementary material The online version of this article (https://doi.org/10.1007/s00401-020-02236-5) contains supplementary material, which is available to authorized users. A paraneoplastic etiology has been reported in few patients with aquaporin-4 (AQP4)-IgG-seropositive neuromyelitis optica spectrum disorders (NMOSD), with lung and breast cancer being the most frequent associated malignancies [[12]]. Cranial magnetic resonance imaging (MRI) revealed a normal optic nerve and a solitary small T2/fluid-attenuated inversion recovery lesion in the right frontal white matter; spinal MRI was unremarkable. [Extracted from the article]

The authors' differential diagnosis included MOGAD, but myelin oligodendrocyte glycoprotein-IgG (MOG-IgG) was negative (tested in 2/3), however, crucial information regarding the timepoint and method are lacking. Diagnosis of myelin oligodendrocyte glycoprotein antibody-associated disease: international MOGAD panel proposed criteria. With great interest, we read the article by Money et al. reporting 3 cases of monkeypox virus disease (MPXV) associated central nervous system (CNS) disease which raised the question if this reflects a para-infectious injury or a viral invasion of the CNS.[1] The reported cases strikingly resemble antibody-mediated CNS myelin oligodendrocyte glycoprotein-IgG-associated disease (MOGAD) in many aspects[2]: (1) patients presented with typical phenotypes, including prodromal phases with fever and myalgia followed by acute disseminated encephalomyelitis (ADEM), longitudinally extensive transverse myelitis (LETM), or encephalopathy with seizures, (2) cerebrospinal fluid (CSF) pleocytosis, (3) prompt treatment response to plasma exchange only, and (4) almost complete clinical and radiographic recovery. [Extracted from the article]

Introduction: To determine an exploratory multimodal approach including serum NFL and MR planimetric measures to discriminate Parkinson's disease (PD), multiple system atrophy (MSA) and progressive supranuclear palsy (PSP).Methods: MR planimetric measurements and NFL serum levels, with a mean time interval of 60 months relative to symptom onset, were assessed in a retrospective cohort of 11 progressive supranuclear palsy (PSP), 22 Parkinson's disease (PD), 16 multiple system atrophy (MSA) patients and 42 healthy controls (HC). A decision tree model to discriminate PD, PSP, and MSA was constructed using receiver operating characteristic curve analysis and Classification and Regression Trees algorithm.Results: Our multimodal decision tree provided accurate differentiation of PD versus MSA and PSP patients using a serum NFL cut-off of 14.66 ng/L. The pontine-to-midbrain-diameter-ratio (Pd/Md) discriminated MSA from PSP at a cut-off value of 2.06. The combined overall diagnostic yield was an accuracy of 83.7% (95% CI 69.8-90.8%).Conclusion: We provide a clinically feasible decision algorithm which combines serum NFL levels and a planimetric MRI marker to differentiate PD, MSA and PSP with high diagnostic accuracy.Classification Of Evidence: This study provides Class III evidence that the combination of serum NFL levels und MR planimetric measurements discriminates between PD, PSP and MSA. [ABSTRACT FROM AUTHOR]

Regarding cardio-pulmonary health, the patient was followed within the prospective observational multicenter COVID study to investigate long-term sequelae in patients hospitalized for SARS-CoV-2 infection (NCT 04416100) that was approved by the local ethics committee (EK 1103/2020). Maintenance of standard immunosuppressive treatment is recommended in mild-to-moderate disease [[7]]; however, information about the management and outcome of patients with severe generalized MG treated with immune-depleting agents such as rituximab is still limited. Dear Sirs, Novel Corona Virus Disease 2019 (COVID-19) poses an unpredictable risk for patients with myasthenia gravis (MG) due to potentially additive effects of bulbar and respiratory muscle weakness and viral lung affection [[1]]. [Extracted from the article]