Myelitis features and outcomes in CNS demyelinating disorders: Comparison between multiple sclerosis, MOGAD, and AQP4-IgG-positive NMOSD

Extracellular Vesicle Marker Changes Associated With Disease Activity in Relapsing-Remitting Multiple Sclerosis

BACKGROUND AND OBJECTIVES

Multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) are autoimmune disorders of the CNS causing severe neurologic impairment. Evidence suggests that extracellular vesicles (EVs) may play a disease-specific role in the orchestration of the immune cell response of MS, NMOSD, and MOGAD. In addition, EVs are considered as a potential source of biomarkers that may allow us to establish molecular signatures for these diseases and perhaps as well to follow treatment effects and disease progression. The aim of this study was to analyze the composition of EVs in patients with relapsing-remitting MS (RRMS) (n = 52), NMOSD (n = 19), and MOGAD (n = 10) and healthy controls ([HCs], n = 15).

METHODS

The concentrations of neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) were determined in plasma using single-molecule array (SIMOA). The size and concentration of tetraspanin-presenting EVs were evaluated in plasma samples with a single-particle interferometric resonance imaging sensor (SP-IRIS). Tetraspanin-independent analyses were performed by nanoparticle-tracking analysis (NTA) after EV isolation by size exclusion (SmartSEC) and cryo-electron microscopy observations. EV epitopes were analyzed by extended multiplex analysis using flow cytometry.

RESULTS

The plasma concentration of NfL and GFAP was significantly higher in patients with RRMS than in HCs. For patients with NMOSD, only GFAP increased. The density of EVs assessed by NTA was lower in plasma of patients with RRMS than in HC plasma. In addition, the 3 disease groups presented increased mean EV sizes in comparison with HCs. Tetraspanin-based EV analyses by SP-IRIS allowed us to observe a modest difference in the level of CD81 in RRMS EVs. In patients with RRMS, but not in those with NMOSD and MOGAD, multiplex/flow cytometry analyses revealed changes in the EV levels of CD29, CD31, and CD69 associated with the time elapsed since the last relapse. The negative correlations established between the vesicular levels of CD31, CD40, CD44, CD49c, CD69, and NfL or GFAP z-scores suggest a negative relationship specifically in RRMS.

DISCUSSION

We speculate that the higher release of EVs containing CD29, CD31, CD40, CD44, CD49c, and CD69 in plasma, at low levels of circulating NfL/GFAP, may be associated with reduced immune cell activity in RRMS. These EV markers may characterize patients with RRMS in disease stabilization.

Enhancing Lesion Detection in Inflammatory Myelopathies: A Deep Learning-Reconstructed Double Inversion Recovery MRI Approach

BACKGROUND AND PURPOSE

The imaging of inflammatory myelopathies has advanced significantly across time, with MRI techniques playing a pivotal role in enhancing lesion detection. However, the impact of deep learning (DL)-based reconstruction on 3D double inversion recovery (DIR) imaging for inflammatory myelopathies remains unassessed. This study aimed to compare the acquisition time, image quality, diagnostic confidence, and lesion detection rates among sagittal T2WI, standard DIR, and DL-reconstructed DIR in patients with inflammatory myelopathies.

MATERIALS AND METHODS

In this observational study, patients diagnosed with inflammatory myelopathies were recruited between June 2023 and March 2024. Each patient underwent sagittal conventional TSE sequences and standard 3D DIR (T2WI and standard 3D DIR were used as references for comparison), followed by an undersampled accelerated double inversion recovery deep learning (DIRDL) examination. Three neuroradiologists evaluated the images using a 4-point Likert scale (from 1 to 4) for overall image quality, perceived SNR, sharpness, artifacts, and diagnostic confidence. The acquisition times and lesion detection rates were also compared among the acquisition protocols.

RESULTS

A total of 149 participants were evaluated (mean age, 40.6 [SD, 16.8] years; 71 women). The median acquisition time for DIRDL was significantly lower than for standard DIR (298 seconds [interquartile range, 288-301 seconds] versus 151 seconds [interquartile range, 148-155 seconds]; P < .001), showing a 49% time reduction. DIRDL images scored higher in overall quality, perceived SNR, and artifact noise reduction (all P < .001). There were no significant differences in sharpness (P = .07) or diagnostic confidence (P = .06) between the standard DIR and DIRDL protocols. Additionally, DIRDL detected 37% more lesions compared with T2WI (300 versus 219; P < .001).

CONCLUSIONS

DIRDL significantly reduces acquisition time and improves image quality compared with standard DIR, without compromising diagnostic confidence. Additionally, DIRDL enhances lesion detection in patients with inflammatory myelopathies, making it a valuable tool in clinical practice. These findings underscore the potential for incorporating DIRDL into future imaging guidelines.

MR Imaging of Autoimmune Inflammatory and Demyelinating Myelopathies

This article examines the MR imaging features of the most common autoimmune inflammatory and demyelinating myelopathies, which encompass disorders characterized by inflammation and subsequent damage to the myelin sheath within the spinal cord. The diagnosis of these conditions relies on a comprehensive approach that includes clinical assessment, neuroradiological evaluation, and laboratory investigations. MR imaging is essential in identifying key features such as signal change, lesion dimension, gadolinium enhancement pattern, and temporal evolution, overall helping to narrow down the differential diagnosis in patients with myelopathy.

Impact of Treatment Delay and Prognostic Factors in Acute Myelitis of Neuromyelitis Optica Spectrum Disease

OBJECTIVE

This study aims to investigate the relationship between treatment delay and poor prognosis in acute myelitis of Neuromyelitis Optica Spectrum Disorder (NMOSD). Additionally, we seek to explore the related factors that contribute to poor prognosis, with the intention of providing more precise clinical guidance.

METHODS

We retrospectively analyzed the acute myelitis attacks of NMOSD patients who were continuously followed up or referred to our hospital from January 2018 to September 2022. We further calculated the proportion of clinical score improvement: (acute-follow-up)/(acute-baseline); poor prognosis was assigned to 0%-33% improvement. The relationship between treatment delay and poor prognosis was evaluated with clustered Receiver Operating Characteristic (ROC) analysis. A Generalized linear mixed model was used to analyze the related factors.

RESULTS

This study included a total of 144 episodes of myelitis attacks, of which 21.5% (31/144) resulted in poor prognosis. Based on the results of the clustered ROC analysis, it has been determined that treatment delay holds significant predictive value for poor prognosis (p = 0.001), with the optimal cut-off point being 15 days. The generalized linear mixed model revealed that factors contributing to poor prognosis in NMOSD myelitis include age (OR, 1.041; CI, 1.013-1.071; p = 0.004) and treatment delay (OR, 1.034; CI, 1.014-1.054; p = 0.001).

CONCLUSION

Our results confirm the treatment delay and age as predictors of poor prognosis in acute myelitis of NMOSD.

Radiological features in pediatric myelin oligodendrocyte glycoprotein antibody-associated disease-diagnostic criteria and lesion dynamics

The spectrum of acquired pediatric demyelinating syndromes has been expanding over the past few years, to include myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), as a distinct neuroimmune entity, in addition to pediatric-onset multiple sclerosis (POMS) and aquaporin 4-IgG-seropositive neuromyelitis optica spectrum disorder (AQP4+NMOSD). The 2023 MOGAD diagnostic criteria require supporting clinical or magnetic resonance imaging (MRI) features in patients with low positive myelin oligodendrocyte glycoprotein IgG titers or when the titers are not available, highlighting the diagnostic role of imaging in MOGAD. In this review, we summarize the key diagnostic features in MOGAD, in comparison to POMS and AQP4+NMOSD. We describe the lesion dynamics both during attack and over time. Finally, we propose a guideline on timing of imaging in clinical practice.

Retrospective, descriptive study of acute myelitis in French Guyana

BACKGROUND

Acute myelitis is a neurological entity, often posing the problem of etiology. The two main causes are infectious or autoimmune. French Guyana is a region of the world where infectious etiologies are multiple, in particular human immunodeficiency virus infection, and autoimmune diseases appear to be emerging. The aim of our study was firstly to determine the proportion of each etiology of acute myelitis in French Guyana, and secondly to describe the clinical, paraclinical and epidemiological characteristics of autoimmune myelitis in French Guyana, with particular reference to neuromyelitis optica spectrum disorder (NMOSD).

METHODS

This retrospective, observational study included all patients who presented with acute myelitis between January 2015 and August 2023 at Cayenne Hospital Center. Each patient's chart was reviewed and patients were classified according to etiology. Demographic and clinical data were collected, as well as blood, lumbar puncture, and cerebral and spinal cord magnetic resonance imaging results.

RESULTS

Of the 40 patients included, immune etiology was found in 74%, including 49% with NMOSD (37% with positive anti-aquaporin-4 antibodies) compared with three patients with infectious etiology. There was no statistically significant difference in complementary examinations between immune and infectious etiologies. The prevalence of NMOSD in French Guyana was estimated at 8/100,000 (6/100,000 for patients with positive anti-aquaporin-4 antibodies). No significant difference in the geographic distribution of patients with NMOSD in French Guyana was demonstrated.

CONCLUSIONS

Our results show a high proportion of autoimmune etiology of acute myelitis in French Guyana, and more particularly of NMOSD. There is a high prevalence of NMOSD, the second highest in the world after the French West Indies. Given this high proportion of autoimmune myelitis, several hypotheses can be put forward, with genetic and environmental factors in the foreground. For patients with acute myelitis in French Guyana, an immune cause is the most likely. It is therefore important to think about this and look for NMOSD in particular, without ignoring an infectious etiology.

MRI management of NMOSD and MOGAD: Proposals from the French Expert Group NOMADMUS

BACKGROUND

Currently, there are no available recommendations or guidelines on how to perform MRI monitoring in the management of neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). The issue is to determine a valuable MRI monitoring protocol to be applied in the management of NMOSD and MOGAD, as previously proposed for the monitoring of multiple sclerosis.

OBJECTIVES

The objectives of this work are to establish proposals for a standardized and feasible MRI acquisition protocol, and to propose control time points for systematic MRI monitoring in the management of NMOSD and MOGAD.

METHODS

A steering committee composed of 7 neurologists and 5 neuroradiologists, experts in NMOSD and MOGAD from the French group NOMADMUS, defined 8 proposals based on their expertise and a review from the literature. These proposals were then submitted to a Rating Group composed of French NMOSD / MOGAD experts.

RESULTS

In the management of NMOSD and MOGAD, a consensus has been reached to perform systematic MRI of the brain, optic nerve and spinal cord, including cauda equina nerve roots, at the time of diagnosis, both without and after gadolinium administration. Moreover, it has been agreed to perform a systematic MRI scan 6 months after diagnosis, focusing on the area of interest, both without and after gadolinium administration. For long-term follow-up of NMOSD and MOGAD, and in the absence of clinical activity, it has been agreed to perform gadolinium-free MRI of the brain (+/- optic nerves) and spinal cord, every 36 months. Ideally, these MRI scans should be performed on the same MRI system, preferably a 3T MRI system for brain and optic nerve MRI, and at least a 1.5T MRI system for spinal cord MRI.

CONCLUSIONS

This expert consensus approach provides physicians with proposals for the MRI management of NMOSD and MOGAD.

A roadmap to increasing access to AQP4-Ig testing for NMOSD: expert recommendations

The discovery of aquaporin 4 immunoglobulin G (AQP4-IgG) autoantibody, present in ∼80% of patients with neuromyelitis optica spectrum disorder (NMOSD), dramatically improved its diagnosis, treatment, and prognosis. While Brazil has a higher prevalence of NMOSD (up to 4.5 per 100,000 people) compared with global averages, disparities in access to testing in Brazil impede early diagnosis and treatment. To tackle these issues, the Americas Health Foundation convened a three-day virtual conference with six Brazilian NMOSD experts. This paper emphasizes the importance of addressing the gaps in physicians' knowledge about NMOSD. Stakeholders, including government agencies, should develop national programs for continuing medical education. The public healthcare system should ensure the availability and accessibility of AQP4-IgG antibody testing. Clinical practice guidelines for NMOSD diagnosis and treatment must be established. Such guidelines will enable healthcare providers to manage patients promptly after the initial attack, reducing relapses and improving quality of life. Finally, addressing the fragmented healthcare system, including bridging the gap between public and private institutions and improving access to telemedicine, will aid individuals in Brazil with NMOSD in receiving early diagnosis and treatment. NMOSD presents unique challenges in Brazil because of its higher prevalence and limited access to crucial AQP4-IgG tests. Overcoming these challenges requires collaboration among experts, healthcare providers, government agencies, and the public healthcare system to improve diagnosis, treatment, and patient outcomes.

Anxiety, Depression, and Expanded Disability Status Scale Independently Predict the Perception of Disability in Persons With Multiple Sclerosis: A Cross-Sectional Study

Multiple sclerosis (MS) is the most common cause of disability in young adults due to several motor, sensory, and cognitive symptoms. However, little is still known about the impact of psychological, cognitive, and social-support variables on subjective disability. This study is aimed at exploring the role of clinical, psychological, cognitive, and social-support variables in predicting disability levels as perceived by persons with multiple sclerosis (pwMS). The World Health Organization Disability Assessment Schedule (WHODAS 2.0) and the Expanded Disability Status Scale (EDSS) were used as subjective and objective measures of disability, respectively. State-Trait Anxiety Inventory and Beck Depression Inventory-II assessed symptoms of anxiety and depression; 19-item Medical Outcome Study-Social Support Survey assessed social support; and Rao's Brief Repeatable Battery assessed cognitive functioning. A multivariable regression analysis was applied using the WHODAS 2.0 as an outcome. One hundred and fifty-one pwMS (93 females, mean age 51.6, standard deviation (SD) 5.8) were enrolled. EDSS (β = 7.190; p < 0.001), state anxiety (β = 0.265; p = 0.009), and symptoms of depression (β = 0.835; p < 0.001) explained a large amount of the variance of subjective disability (Adj.R 2 = 0.705; p < 0.001) measured through the WHODAS 2.0. Contrarily, cognitive functioning and perceived social support are not independently associated with the WHODAS 2.0 score. Psychosocial interventions in rehabilitation settings, aimed at reducing the overall perceived disability of pwMS, should be implemented in rehabilitation programs.

The Importance of Bright Spotty Lesions on Magnetic Resonance Imaging in Predicting Chronic Neuropathic Pain in Myelitis

Background/Objectives: Chronic neuropathic pain (CNP) stands as one of the most debilitating complications in patients with myelitis owing to its challenging management. Bright spotty lesions (BSLs) are frequently observed in neuromyelitis optica spectrum disorder (NMOSD), but few reports have discussed CNP in myelitis. We aim to demonstrate that BSLs could be one of the potential prognostic factors for CNP development in myelitis. Methods: We examined 63 patients diagnosed with myelitis. Patients were categorized into CNP and non-CNP groups. We assessed the severity of clinical symptoms and the oral steroid dose administered after pulse therapy. Spine magnetic resonance imaging (MRI) of each patient was reviewed to analyze the characteristics of myelitis. Serological and cerebrospinal fluid (CSF) findings were also examined to confirm the etiology. Results: CNP was observed in 27 patients (42.9%). The mean onset age of patients with CNP was 45.26 ± 14.16 years. The MRI lesions exhibited more enhanced features and bright spotty lesions (BSLs) in the CNP group (χ2 test, p < 0.05). Patients with CNP received a lower oral steroid dose during the first month after symptom onset (χ2 test, p < 0.05). Multivariate logistic regression analysis revealed that patients with CNP exhibited significant BSLs in their myelitis lesions on spine MRI (OR 4.965; 95% CI, 1.282 to 19.235, p = 0.02). Conclusions: Although the exact mechanism remains unknown, the presence of BSLs on spine MRI could serve as an independent prognostic factor for CNP development. Additionally, our study suggests that lower oral steroid doses administered immediately after symptom onset are associated with CNP development. Further investigation with a larger cohort is warranted to validate our findings.

The next frontier in multiple sclerosis therapies: Current advances and evolving targets

Recent advancements in research have significantly enhanced our comprehension of the intricate immune components that contribute to multiple sclerosis (MS) pathogenesis. By conducting an in-depth analysis of complex molecular interactions involved in the immunological cascade of the disease, researchers have successfully identified novel therapeutic targets, leading to the development of innovative therapies. Leveraging pioneering technologies in proteomics, genomics, and the assessment of environmental factors has expedited our understanding of the vulnerability and impact of these factors on the progression of MS. Furthermore, these advances have facilitated the detection of significant biomarkers for evaluating disease activity. By integrating these findings, researchers can design novel molecules to identify new targets, paving the way for improved treatments and enhanced patient care. Our review presents recent discoveries regarding the pathogenesis of MS, highlights their genetic implications, and proposes an insightful approach for engaging with newer therapeutic targets in effectively managing this debilitating condition.

Review of clinical and imaging findings in autoimmune glial fibrillary acidic protein astrocytopathy to aid in early diagnosis

Objective

Autoimmune glial fibrillary acidic protein astrocytopathy (GFAP-A) is a novel steroid sensitive autoimmune disease, without a diagnostic consensus. The purpose of this study was to improve early GFAP-A diagnosis by increasing awareness of key clinical characteristics and imaging manifestations.

Methods

Medical records of 13 patients with anti-GFAP antibodies in serum or cerebrospinal fluid (CSF) were reviewed for cross-sectional and longitudinal analysis of clinical and magnetic resonance imaging (MRI) findings.

Results

The predominant GFAP-A clinical manifestations are limb weakness/numbness and fever. GFAP-A has a propensity in the early stage for meningeal and leptomeningeal lesions on the brainstem surface, with a typical pattern of periventricular linear radial and leptomeningeal enhancement. The clinical manifestations and leptomeningeal enhancement were rapidly alleviated after treatment with high doses of corticosteroids or/and intravenous immunoglobulin, although, there are patients who may present with increased brain parenchymal lesions. On 3T MRI, the spinal cord demonstrated extensive longitudinal T2-weighted hyper-intensity, central distribution, and gray matter involvement. Optic nerve involvement in some patients was also noted with optic nerve swelling and abnormal enhancement. In addition to the classic reversible splenium of corpus callosum syndrome (type I), this study found the much rarer type II with diffusion restriction on DWI (Diffusion Weighted Imaging) in the corpus callosum. Positive anti-GFAP antibodies in serum or cerebrospinal fluid (CSF) are important for GFAP-A diagnosis with overlapping antibodies commonly noted. This study found anti-GM3 antibodies, a rare finding also previously reported.

Conclusion

This study correlates GFAP-A clinical and imaging features, noting a "delay" phenomenon between clinical manifestations, treatment response, and radiographic MRI findings. MRI T2-FLAIR brainstem hyperintensity and T2-FLAIR gadolinium enhanced images, and subtraction techniques were valuable for early lesion detection and accurate diagnosis.

A Case of Neuromyelitis Optica Spectrum Disorder With Improvement in Urinary Retention After the Administration of Ravulizumab

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disease that causes recurrent neuritis and myelitis. Ravulizumab, a complement protein C5 inhibitor, was developed to treat NMOSD. However, its efficacy in improving symptoms remains unclear. This case report describes the case of a 30-year-old woman with NMOSD who developed thoracic myelitis. Initial treatment with high-dose methylprednisolone and hemodialysis alleviated paraplegia, although urinary retention persisted. Two months after initiating ravulizumab treatment, urinary function improved. Ravulizumab administration may have contributed to the improved urinary retention.

Pediatric acquired demyelinating syndromes: updates in diagnosis, testing, and management

PURPOSE OF REVIEW

To highlight the clinical presentation, diagnostic approach, and management of acquired inflammatory demyelinating syndromes in children.

RECENT FINDINGS

The identification of myelin oligodendrocyte glycoprotein antibody-associated disease in 2017 and evolving evidence regarding best practices for management has had a significant impact on pediatric neuroimmunology, as has the shift in treatment of pediatric-onset multiple sclerosis, with the use of high-efficacy disease-modifying therapies early in the disease course.

SUMMARY

With expanding awareness and growing interest in pediatric onset neuroinflammatory conditions, the number of children diagnosed with acquired demyelinating syndromes is rising. It is critical to refine our understanding of the underlying pathophysiological mechanisms in these disorders to provide the most effective care. Much of our practice continues to be modeled on adult care, and further large-scale pediatric studies are necessary to explore the natural history and assess the safety and efficacy of immunotherapies in childhood-onset demyelinating diseases.

The influence of MOGAD on diagnosis of multiple sclerosis using MRI

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is an immune-mediated demyelinating disease that is challenging to differentiate from multiple sclerosis (MS), as the clinical phenotypes overlap, and people with MOGAD can fulfil the current MRI-based diagnostic criteria for MS. In addition, the MOG antibody assays that are an essential component of MOGAD diagnosis are not standardized. Accurate diagnosis of MOGAD is crucial because the treatments and long-term prognosis differ from those for MS. This Expert Recommendation summarizes the outcomes from a Magnetic Resonance Imaging in MS workshop held in Oxford, UK in May 2022, in which MS and MOGAD experts reflected on the pathology and clinical features of these disorders, the contributions of MRI to their diagnosis and the clinical use of the MOG antibody assay. We also critically reviewed the literature to assess the validity of distinctive imaging features in the current MS and MOGAD criteria. We conclude that dedicated orbital and spinal cord imaging (with axial slices) can inform MOGAD diagnosis and also illuminate differential diagnoses. We provide practical guidance to neurologists and neuroradiologists on how to navigate the current MOGAD and MS criteria. We suggest a strategy that includes useful imaging discriminators on standard clinical MRI and discuss imaging features detected by non-conventional MRI sequences that demonstrate promise in differentiating these two disorders.

Overview and Diagnostic Approach in Autoimmune Neurology

OBJECTIVE

The field of autoimmune neurology is rapidly evolving. This article reviews the epidemiology and pathophysiology as well as current approaches to clinical and paraclinical assessment, testing paradigms, and general principles of treatment.

LATEST DEVELOPMENTS

Improved recognition of autoimmune diagnoses among patients who have phenotypically diverse, subacute onset neurologic presentations is facilitated by disease-specific antibody biomarker discovery. These antibodies have varying associations with paraneoplastic causation (from no association to greater than 70% positive predictive value), immunotherapy responses, and outcomes. To simplify assessment in an increasingly complex discipline, neurologic phenotype-specific serum and CSF antibody evaluations are recommended. Clinical trials have led to the approval of monoclonal therapies for neuromyelitis optica spectrum disorder (NMOSD) and are underway for N-methyl-d-aspartate (NMDA) receptor and leucine-rich glioma inactivated protein 1 (LGI1) encephalitides.

ESSENTIAL POINTS

Autoimmune neurology is now a mainstream subspecialty, consisting of disorders with diverse presentations detectable using antibody testing of serum and CSF. Early and sustained immunotherapy (eg, corticosteroids, intravenous immunoglobulin [IVIg], plasma exchange) is recommended and may be supplemented by immune suppressants (eg, rituximab or cyclophosphamide) to sustain responses and optimize outcomes.

NMOSD and MOGAD

OBJECTIVE

This article reviews the clinical features, MRI characteristics, diagnosis, and treatment of aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). The main differences between these disorders and multiple sclerosis (MS), the most common demyelinating disease of the central nervous system (CNS), are also highlighted.

LATEST DEVELOPMENTS

The past 20 years have seen important advances in understanding rare demyelinating CNS disorders associated with AQP4 IgG and myelin oligodendrocyte glycoprotein (MOG) IgG. The rapidly expanding repertoire of immunosuppressive agents approved for the treatment of AQP4-NMOSD and emerging as potentially beneficial in MOGAD mandates prompt recognition of these diseases. Most of the recent literature has focused on the identification of clinical and MRI features that help distinguish these diseases from each other and MS, simultaneously highlighting major diagnostic pitfalls that may lead to misdiagnosis. An awareness of the limitations of currently available assays for AQP4 IgG and MOG IgG detection is fundamental for identifying rare false antibody positivity and avoiding inappropriate treatments. For this purpose, diagnostic criteria have been created to help the clinician interpret antibody testing results and recognize the clinical and MRI phenotypes associated with AQP4-NMOSD and MOGAD.

ESSENTIAL POINTS

An awareness of the specific clinical and MRI features associated with AQP4-NMOSD and MOGAD and the limitations of currently available antibody testing assays is crucial for a correct diagnosis and differentiation from MS. The growing availability of effective treatment options will lead to personalized therapies and improved outcomes.

Neuromyelitis optica spectrum disorder: Exploring the diverse clinical manifestations and the need for further exploration

BACKGROUND

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune disorder characterized by inflammatory assaults on the central nervous system (CNS), particularly on the optic nerves and spinal cord. In recent years, a wider range of clinical manifestations of this complex disease have been observed, emphasizing the importance of gaining a more profound understanding beyond optic neuritis (ON) and transverse myelitis (TM).

CURRENT KNOWLEDGE

This study explores the many clinical symptoms of NMOSD, including common and uncommon presentations. Distinctive aspects of ON, TM, and diencephalic/brainstem syndromes are examined, highlighting their unique characteristics in contrast to conditions such as multiple sclerosis. We also discuss extra-CNS involvement, such as unusual signs, including muscle involvement, retinal injury, auditory impairment, and rhinological symptoms.

AIMS AND OBJECTIVES

Our study intends to highlight the wide range and complexity of NMOSD presentations, emphasizing the significance of identifying unusual symptoms for precise diagnosis and prompt management. The specific processes that contribute to the varied clinical presentation of NMOSD are not well understood despite existing information. This emphasizes the necessity for more study to clarify the mechanisms that cause different symptoms and discover new treatment targets for this complex autoimmune disorder.

CONCLUSION

It is essential to acknowledge the complex and varied clinical manifestations of NMOSD to enhance diagnosis, treatment, and patient results. By enhancing our comprehension of the fundamental processes and investigating innovative therapeutic approaches, we may aim to enhance the quality of life for persons impacted by this illness.

Diffusion Tensor Imaging Identifies Cervical Spondylosis, Myelitis, and Spinal Cord Tumors

BACKGROUND

Diffusion tensor imaging (DTI) has been increasingly recognized for its capability to study microstructural changes in the neuropathology of brain diseases. However, the optimal DTI metric and its diagnostic utility for a variety of spinal cord diseases are still under investigation.

PURPOSE

To evaluate the diagnostic efficacy of DTI metrics for differentiating between cervical spondylosis, myelitis, and spinal tumors.

METHODS

This retrospective study analyzed DTI scans from 68 patients (22 with cervical spondylosis, 23 with myelitis, and 23 with spinal tumors). DTI indicators, including fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD) and axial diffusivity (AD), were calculated. The Kruskal-Wallis test was used to compare these indicators, followed by Receiver Operating Characteristic (ROC) curve analysis, to evaluate the diagnostic efficacy of each indicator across disease pairs. Additionally, we explored the correlations of DTI indicators with specific clinical measurements.

RESULTS

FA values were significantly lower in tumor patients compared to those with cervical spondylosis (p < 0.0001) and myelitis (p < 0.05). Additionally, tumor patients exhibited significantly elevated MD and RD values relative to the spondylosis and myelitis groups. ROC curve analysis underscored FA's superior discriminative performance, with an area under the curve (AUC) of 0.902 for differentiating tumors from cervical spondylosis, and an AUC of 0.748 for distinguishing cervical myelitis from spondylosis. Furthermore, a significant negative correlation was observed between FA values and Expanded Disability Status Scores (EDSSs) in myelitis patients (r = -0.62, p = 0.002), as well as between FA values and Ki-67 scores in tumor patients (r = -0.71, p = 0.0002).

CONCLUSION

DTI indicators, especially FA, have the potential in distinguishing spondylosis, myelitis, and spinal cord tumors. The significant correlation between FA values and clinical indicators highlights the value of FA in the clinical assessment and prognosis of spinal diseases and may be applied in diagnostic protocols in the future.

Development Perspectives for Curative Technologies in Primary Demyelinating Disorders of the Central Nervous System with Neuromyelitis Optica Spectrum Disorder (NMOSD) and Myelin Oligodendrocyte Glycoprotein Antibody-Associated Disease (MOGAD) at the Forefront

Primary demyelinating disorders of the central nervous system (CNS) include multiple sclerosis and the orphan conditions neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein IgG-associated disease (MOGAD). Curative technologies under development aim to selectively block autoimmune reactions against specific autoantigens while preserving the responsiveness of the immune system to other antigens. Our analysis focused on target patient selection for such developments, carefully considering the relevant clinical, regulatory, and market-related aspects. We found that the selection of patients with orphan conditions as target populations offers several advantages. Treatments for orphan conditions are associated with limited production capacity, qualify for regulatory incentives, and may require significantly shorter and lower-scale clinical programs. Furthermore, they may meet a higher acceptable cost-effectiveness threshold in order to compensate for the low numbers of patients to be treated. Finally, curative technologies targeting orphan indications could enter less competitive markets with lower risk of generic price erosion and would benefit from additional market protection measures available only for orphan products. These advantages position orphan conditions and subgroups as the most attractive target indications among primary demyelinating disorders of the CNS. The authors believe that after successful proof-of-principle demonstrations in orphan conditions, broader autoimmune patient populations may also benefit from the success of these pioneering developments.

Clinical characteristics of patients with myelin oligodendrocyte glycoprotein antibodies

PURPOSE OF REVIEW

The clinical landscape associated to myelin oligodendrocyte glycoprotein antibodies (MOG-Ab) has undergone a remarkable transformation over the past two decades, primarily driven by advancements in antibody detection techniques that have enhanced both the specificity and sensitivity of assays, enabling the identification of novel clinical phenotypes.

RECENT FINDINGS

Recent pivotal research publications, comprehensive reviews from established research groups, and most notably the first proposed international criteria for MOG-Ab associated disease (MOGAD) have substantially enriched our understanding of the clinical features associated with MOG-Ab. This review presents a comprehensive overview of the clinical characteristics of patients with MOG-Ab, systematically examining each core clinical syndrome defined by the proposed international MOGAD criteria. We incorporated recent insights and discussed potential challenges in applying these criteria across diverse clinical scenarios.

SUMMARY

The proposed international MOGAD criteria provide a comprehensive, homogeneous, and specific framework for characterizing the clinical features of patients with MOG-Ab, encompassing both paediatric and adult populations. In the future, the widespread adoption of specific and reliable assays for MOG-Ab detection, complemented by the development of surrogate fluid and imaging markers, holds promise for better characterizing atypical presentations, only-cerebrospinal fluid positivity and the MOGAD "seronegative" situations.

The distinction of area postrema syndrome between MOGAD and NMOSD

Background and objectives

Both myelin oligodendrocyte glycoprotein-IgG associated disorders (MOGAD) and neuromyelitis optica spectrum disorder (NMOSD) are demyelinating diseases of the central nervous system. They present similar clinical manifestations such as optica neuritis, myelitis and area postrema syndrome (APS). The distinctions of optica neuritis (ON) and myelitis between them have been elaborated to great length while their differences in APS remain to be elucidated. We aim to report the frequency of APS in patients with MOGAD as well as NNOSD patients, and to compare the characteristics of APS between patients with MOGAD and those with NMOSD.

Methods

Seven MOG-IgG positive APS patients were retrospectively identified between 2017 and 2022. APS phenotypes have been previously described. The similarities and differences between MOGAD and NMOSD patients with APS was compared, including the frequency and duration of APS between the two diseases, and their incidences of accompanied subtentorial lesions have also been described and compared.

Results

We reviewed a cohort of 218 MOG-IgG-positive patients, and 396 patients with NMOSD. 200 MOGAD patients and 332 NMOSD patients were included in this study. In the cohort, seven patients with MOG-IgG-positive antibody presented with APS were analyzed, four of whom had disease onset with APS. Of the 332 patients with NMOSD, 47 had APS attacks while 31 had APS at disease onset. In patients with MOGAD, 2 had nausea, 3 had vomiting, 5 had hiccups, and 1 patient presented with all three symptoms above. In patients with NMOSD, 70.2 % had nausea, vomiting and hiccups at the same time during APS attacks. Apart from the medulla oblongata, other subtentorial regions were also affected in 6/7 MOGAD patients while 14/47 NMOSD patients had other subtentorial regions involved. During an APS attack, the incidence of concomitant lesions in the brainstem and other regions was significantly greater in MOGAD than in the NMOSD cohort (P = 0.008*).

Conclusion

APS is a rare, but not isolated clinical manifestation of MOGAD. APS happened more frequently with other supratentorial and subtentorial lesions in MOGAD. The symptoms of NVH (nausea, vomiting, hiccups) tended to happen respectively in MOGAD compared with NMOSD. The phenotype or mechanism of APS in MOGAD may differ from that in NMOSD.

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

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

Brain and spinal cord atrophy in NMOSD and MOGAD: Current evidence and future perspectives

Neuromyelitis optica spectrum disorder (NMOSD) is a severe form of inflammation of the central nervous system (CNS) including acute myelitis, optic neuritis and brain syndrome. Currently, the classification of NMOSD relies on serologic testing, distinguishing between seropositive or seronegative anti-aquaporin-4 antibody (AQP4) status. However, the situation has recently grown more intricate with the identification of patients exhibiting the NMOSD phenotype and myelin oligodendrocyte glycoprotein antibodies (MOGAD). NMOSD is primarily recognized as a relapsing disorder; MOGAD can manifest with either a monophasic or relapsing course. Significant symptomatic inflammatory CNS injuries with stability in clinical findings outside the acute phase are reported in both diseases. Nevertheless, recent studies have proposed the existence of a subclinical pathological process, revealing longitudinal changes in brain and spinal cord atrophy. Within this context, we summarise key studies investigating brain and spinal cord measurements in adult NMOSD and MOGAD. We also explore their relationship with clinical aspects, highlight differences from multiple sclerosis (MS), and address future challenges. This exploration is crucial for determining the presence of chronic damage processes, enabling the customization of therapeutic interventions irrespective of the acute phase of the disease.

Clinical Approach to Myelopathy Diagnosis

OBJECTIVE

This article describes an integrative strategy to evaluate patients with suspected myelopathy, provides advice on diagnostic approach, and outlines the framework for the etiologic diagnosis of myelopathies.

LATEST DEVELOPMENTS

Advances in diagnostic neuroimaging techniques of the spinal cord and improved understanding of the immune pathogenic mechanisms associated with spinal cord disorders have expanded the knowledge of inflammatory and noninflammatory myelopathies. The discovery of biomarkers of disease, such as anti-aquaporin 4 and anti-myelin oligodendrocyte glycoprotein antibodies involved in myelitis and other immune-related mechanisms, the emergence and identification of infectious disorders that target the spinal cord, and better recognition of myelopathies associated with vascular pathologies have expanded our knowledge about the broad clinical spectrum of myelopathies.

ESSENTIAL POINTS

Myelopathies include a group of inflammatory and noninflammatory disorders of the spinal cord that exhibit a wide variety of motor, sensory, gait, and sensory disturbances and produce major neurologic disability. Both inflammatory and noninflammatory myelopathies comprise a broad spectrum of pathophysiologic mechanisms and etiologic factors that lead to specific clinical features and presentations. Knowledge of the clinical variety of myelopathies and understanding of strategies for the precise diagnosis, identification of etiologic factors, and implementation of therapies can help improve outcomes.

Multiple Sclerosis: New Insights into Molecular Pathogenesis and Novel Platforms for Disease Treatment

BACKGROUND

Multiple sclerosis (MS), a chronic inflammatory disorder, affects the central nervous system via myelin degradation. The cause of MS is not fully known, but during recent years, our knowledge has deepened significantly regarding the different aspects of MS, including etiology, molecular pathophysiology, diagnosis and therapeutic options. Myelin basic protein (MBP) is the main myelin protein that accounts for maintaining the stability of the myelin sheath. Recent evidence has revealed that MBP citrullination or deamination, which is catalyzed by Ca2+ dependent peptidyl arginine deiminase (PAD) enzyme leads to the reduction of positive charge, and subsequently proteolytic cleavage of MBP. The overexpression of PAD2 in the brains of MS patients plays an essential role in new epitope formation and progression of the autoimmune disorder. Some drugs have recently entered phase III clinical trials with promising efficacy and will probably obtain approval in the near future. As different therapeutic platforms develop, finding an optimal treatment for each individual patient will be more challenging.

AIMS

This review provides a comprehensive insight into MS with a focus on its pathogenesis and recent advances in diagnostic methods and its present and upcoming treatment modalities.

CONCLUSION

MS therapy alters quickly as research findings and therapeutic options surrounding MS expand. McDonald's guidelines have created different criteria for MS diagnosis. In recent years, ever-growing interest in the development of PAD inhibitors has led to the generation of many reversible and irreversible PAD inhibitors against the disease with satisfactory therapeutic outcomes.

The pathogenesis of multiple sclerosis: a series of unfortunate events

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

A comprehensive review of the advances in neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a rare relapsing neuroinflammatory autoimmune astrocytopathy, with a predilection for the optic nerves and spinal cord. Most cases are characterised by aquaporin-4-antibody positivity and have a relapsing disease course, which is associated with accrual of disability. Although the prognosis in NMOSD has improved markedly over the past few years owing to advances in diagnosis and therapeutics, it remains a severe disease. In this article, we review the evolution of our understanding of NMOSD, its pathogenesis, clinical features, disease course, treatment options and associated symptoms. We also address the gaps in knowledge and areas for future research focus.

Serum neurofilament light chain predicts spinal cord atrophy in neuromyelitis optica spectrum disorder

Levels of serum neurofilament light chain (sNfL) and serum glial fibrillary acidic protein (sGFAP) are useful biomarkers of disease activity and disability in neuromyelitis optica spectrum disorder (NMOSD). Here we investigated the association of sNfL and sGFAP levels with brain and spinal cord volumes in patients with NMOSD. Fifteen patients with NMOSD were enrolled in this prospective study. The median baseline level of sNfL was 42.2 (IQR, 16.1-72.6) pg/mL and decreased to 8.5 (IQR, 7.4-16.6) pg/mL at the end of the study. The reduction in sNfL was associated with a 7.5% loss of cervical spinal cord volume (CSCV) (p = 0.001). The levels of sGFAP reduced from 239.2 (IQR, 139.0-3393.3) pg/mL at baseline to 108.5 (IQR, 74.2-154.6) pg/mL. However, there was no strong correlation between sGFAP levels and CSCV changes during the follow-up period. Our data suggested that sNfL level is a useful biomarker for predicting spinal cord atrophy in patients with NMOSD.

Non-demyelinating disorders mimicking and misdiagnosed as NMOSD: a literature review

BACKGROUND

Differentiating neuromyelitis optica spectrum disorder (NMOSD) from its mimics is crucial to avoid misdiagnosis, especially in the absence of aquaporin-4-IgG. While multiple sclerosis (MS) and myelin oligodendrocyte glycoprotein-IgG associated disease (MOGAD) represent major and well-defined differential diagnoses, non-demyelinating NMOSD mimics remain poorly characterized.

METHODS

We conducted a systematic review on PubMed/MEDLINE to identify reports of patients with non-demyelinating disorders that mimicked or were misdiagnosed as NMOSD. Three novel cases seen at the authors' institutions were also included. The characteristics of NMOSD mimics were analyzed and red flags associated with misdiagnosis identified.

RESULTS

A total of 68 patients were included; 35 (52%) were female. Median age at symptoms onset was 44 (range, 1-78) years. Fifty-six (82%) patients did not fulfil the 2015 NMOSD diagnostic criteria. The clinical syndromes misinterpreted for NMOSD were myelopathy (41%), myelopathy + optic neuropathy (41%), optic neuropathy (6%), or other (12%). Alternative etiologies included genetic/metabolic disorders, neoplasms, infections, vascular disorders, spondylosis, and other immune-mediated disorders. Common red flags associated with misdiagnosis were lack of cerebrospinal fluid (CSF) pleocytosis (57%), lack of response to immunotherapy (55%), progressive disease course (54%), and lack of magnetic resonance imaging gadolinium enhancement (31%). Aquaporin-4-IgG positivity was detected in five patients by enzyme-linked immunosorbent assay (n = 2), cell-based assay (n = 2: serum, 1; CSF, 1), and non-specified assay (n = 1).

CONCLUSIONS

The spectrum of NMOSD mimics is broad. Misdiagnosis frequently results from incorrect application of diagnostic criteria, in patients with multiple identifiable red flags. False aquaporin-4-IgG positivity, generally from nonspecific testing assays, may rarely contribute to misdiagnosis.

A retrospective study of myelin oligodendrocyte glycoprotein antibody-associated disease from a clinical laboratory perspective

Objectives

To analyze the differences in laboratory data between patients with myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD), multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD).

Methods

The study included 26 MOGAD patients who visited Beijing Tiantan Hospital from 2018 to 2021. MS and NMOSD patients who visited the clinic during the same period were selected as controls. Relevant indicators were compared between the MOGAD group and the MS/NMOSD groups, and the diagnostic performance of meaningful markers was assessed.

Results

The MOGAD group showed a slight female preponderance of 57.7%, with an average onset age of 29.8 years. The absolute and relative counts of neutrophils were higher in the MOGAD group than in the MS group, while the proportion of lymphocytes was lower. The cerebrospinal fluid (CSF) IgG level, IgG index, 24-h IgG synthesis rate, and positive rate of oligoclonal bands (OCB) were lower in MOGAD patients than in the MS group. The area under ROC curve (AUC) was 0.939 when combining the relative lymphocyte count and IgG index. Compared to the NMOSD group, the MOGAD group had higher levels of serum complement C4 and lower levels of serum IgG. The AUC of serum C4 combined with FT4 was 0.783.

Conclusion

Statistically significant markers were observed in the laboratory data of MOGAD patients compared to MS/NMOSD patients. The relative lymphocyte count combined with IgG index had excellent diagnostic efficacy for MOGAD and MS, while serum C4 combined with FT4 had better diagnostic efficacy for MOGAD and NMOSD.

Gastrointestinal Dysfunction in Multiple Sclerosis and Related Conditions

Nervous system disorders may be accompanied by gastrointestinal (GI) dysfunction. Brain lesions may be responsible for GI problems such as decreased peristalsis (e.g., lesions in the basal ganglia, pontine defecation center/Barrington's nucleus), decreased abdominal strain (e.g., lesions in the parabrachial nucleus), hiccupping and vomiting (e.g., lesions in the area postrema), and appetite loss (e.g., lesions in the hypothalamus). Decreased peristalsis also may be caused by lesions of the spinal long tracts or the intermediolateral nucleus projecting to the myenteric plexus. This review addresses GI dysfunction caused by multiple sclerosis, neuromyelitis optica spectrum disorder, and myelin oligodendrocyte glycoprotein-associated disorder. Neuro-associated GI dysfunction may develop concurrently with brain or spinal cord dysfunction or may predate it. Collaboration between gastroenterologists and neurologists is highly desirable when caring for patients with GI dysfunction related to nervous system disorders, particularly since patients with these symptoms may visit a gastroenterologist prior to the establishment of a neurological diagnosis.

Transverse myelitis in myelin oligodendrocyte glycoprotein antibody-associated disease

Transverse myelitis (TM) is the second most common presentation of myelin oligodendrocyte antibody-associated disease (MOGAD), occurring in approximately 26% of affected patients. The diagnosis may be complicated by the lack of diagnostic specificity of low titers of MOG antibody in serum, fluctuation in seropositivity overtime, including initially normal MRI in up to 10% of patients, and in many instances complete resolution of radiological abnormalities when MRI is done in a significantly delayed fashion. The use of preventive disease modifying treatments is limited by the uncertainty whether the disease process will remain monophasic or become relapsing, as well as by the lack FDA approved treatments. In this review, we discuss clinical, radiological and cerebrospinal fluid (CSF) characteristics, including the significance of MOG titers and changes in the seropositivity status for the diagnosis of MOGAD-associated TM, its radiological features and management options, highlighting the data on the risk of relapses associated with TM at presentation and the need for further randomized clinical trials to empower effective treatment algorithms.

Identifying specific myelopathy etiologies in the evaluation of suspected myelitis: A retrospective analysis

BACKGROUND

Myelopathies require prompt etiologic diagnosis. We aimed to identify a specific myelopathy diagnosis in cases of suspected myelitis to highlight clinicoradiologic differences.

METHODS

In this retrospective, single-centre cohort of subjects with suspected myelitis referred to London Multiple Sclerosis (MS) Clinic between 2006 and 2021, we identified those with MS and reviewed the remaining charts for etiologic diagnosis based on clinical, serologic, and imaging details.

RESULTS

Of 333 included subjects, 318/333 (95.5%) received an etiologic diagnosis. Most (274/333, 82%) had MS or clinically isolated syndrome. Spinal cord infarction (n = 10) was the commonest non-inflammatory myelitis mimic characterized by hyperacute decline (n = 10/10, 100%), antecedent claudication (n = 2/10, 20%), axial owl/snake eye (n = 7/9, 77%) and sagittal pencillike (n = 8/9, 89%) MRI patterns, vertebral artery occlusion/stenosis (n = 4/10, 40%), and concurrent acute cerebral infarct (n = 3/9, 33%). Longitudinal lesions were frequent in aquaporin-4-IgG-positive neuromyelitis optica spectrum disorder (AQP4+NMOSD) (n = 7/7, 100%) and myelin oligodendrocyte glycoprotein-IgG-associated disorder (MOGAD) (n = 6/7, 86%), accompanied by bright spotty (n = 5/7, 71%) and central-grey-restricted (n = 4/7, 57%) T2-lesions on axial sequences, respectively. Leptomeningeal (n = 4/4, 100%), dorsal subpial (n = 4/4, 100%) enhancement, and positive body PET/CT (n = 4/4, 100%) aided the diagnosis of sarcoidosis. Spondylotic myelopathies had chronic sensorimotor presentations (n = 4/6, 67%) with relative bladder sparing (n = 5/6, 83%), localizable to sites of disc herniation (n = 6/6, 100%). Metabolic myelopathies showed dorsal column or inverted 'V' sign (n = 2/3, 67%) MRI T2-abnormality with B12 deficiency.

CONCLUSIONS

Although no single feature reliably confirms or refutes a specific myelopathy diagnosis, this study highlights patterns that narrow the differential diagnosis of myelitis and facilitate early recognition of mimics.

Neuromyelitis Optica Spectrum Disorders: Clinical Perspectives, Molecular Mechanisms, and Treatments

Neuromyelitis optica (NMO) is a rare autoimmune inflammatory disorder affecting the central nervous system (CNS), specifically the optic nerve and the spinal cord, with severe clinical manifestations, including optic neuritis (ON) and transverse myelitis. Initially, NMO was wrongly understood as a condition related to multiple sclerosis (MS), due to a few similar clinical and radiological features, until the discovery of the AQP4 antibody (NMO-IgG/AQP4-ab). Various etiological factors, such as genetic-environmental factors, medication, low levels of vitamins, and others, contribute to the initiation of NMO pathogenesis. The autoantibodies against AQP4 target the AQP4 channel at the blood–brain barrier (BBB) of the astrocyte end feet, which leads to high permeability or leakage of the BBB that causes more influx of AQP4-antibodies into the cerebrospinal fluid (CSF) of NMO patients. The binding of AQP4-IgG onto the AQP4 extracellular epitopes initiates astrocyte damage through complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC). Thus, a membrane attack complex is formed due to complement cascade activation; the membrane attack complex targets the AQP4 channels in the astrocytes, leading to astrocyte cell damage, demyelination of neurons and oligodendrocytes, and neuroinflammation. The treatment of NMOSD could improve relapse symptoms, restore neurological functions, and alleviate immunosuppression. Corticosteroids, apheresis therapies, immunosuppressive drugs, and B cell inactivating and complement cascade blocking agents have been used to treat NMOSD. This review intends to provide all possible recent studies related to molecular mechanisms, clinical perspectives, and treatment methodologies of the disease, particularly focusing on recent developments in clinical criteria and therapeutic formulations.

Upregulation of C-X-C motif chemokine 12 in the spinal cord alleviated the symptoms of experimental autoimmune encephalomyelitis in Lewis rats

Background

C-X-C motif chemokine 12 (CXCL12) is a chemokine that performs many functions. Studies have shown that CXCL12 can aggravate inflammatory symptoms in the central nervous system (CNS). Evidence also indicates that CXCL12 can promote the repair of myelin sheaths in the CNS in experimental autoimmune encephalomyelitis (EAE). Here, we investigated the function of CXCL12 in CNS inflammation by upregulating CXCL12 in the spinal cord and subsequently inducing EAE.

Materials and methods

CXCL12 upregulation in the spinal cords of Lewis rats was induced by the injection of adeno-associated virus 9 (AAV9)/eGFP-P2A-CXCL12 after intrathecal catheter implantation. Twenty-one days after AAV injection, EAE was induced and clinical score was collected; Immunofluorescence staining, WB and LFB-PAS staining were used to evaluate the effect of CXCL12 upregulation. In the in vitro study, oligodendrocyte precursor cells (OPCs) were harvested, cultured with CXCL12 and AMD3100, and subjected to immunofluorescence staining for functional assessment.

Results

CXCL12 was upregulated in the lumbar enlargement of the spinal cord by AAV injection. In each stage of EAE, upregulation of CXCL12 significantly alleviated clinical scores by inhibiting leukocyte infiltration and promoting remyelination. In contrast, the addition of AMD3100, which is a CXCR4 antagonist, inhibited the effect of CXCL12. In vitro, 10 ng/ml CXCL12 promoted the differentiation of OPCs into oligodendrocytes.

Conclusion

AAV-mediated upregulation of CXCL12 in the CNS can alleviate the clinical signs and symptoms of EAE and significantly decrease the infiltration of leukocytes in the peak stage of EAE. CXCL12 can promote the maturation and differentiation of OPCs into oligodendrocytes in vitro. These data indicate that CXCL12 effectively promotes remyelination in the spinal cord and decreases the signs and symptoms of EAE.