A Comprehensive Review on the Role of Genetic Factors in Neuromyelitis Optica Spectrum Disorder

Neuromyelitis in a Patient with Rheumatoid Arthritis: A Case Report

A patient with longstanding rheumatoid arthritis (RA) complained of spinal cord symptoms after RA relapse. Contrast MRI demonstrated neuromyelitis in the upper thoracic spinal cord, and anti-aquaporin-4 (anti-AQP4) antibody was positive in the serum and cerebrospinal fluid (CSF). Neuromyelitis optica spectrum disorder (NMOSD) was diagnosed after excluding central nervous system (CNS) infection and tumor, and spinal cord symptoms were relieved after high dose of glucocorticoid and immunosuppressant were initiated for treatment.

Interferon-γ controls aquaporin 4-specific Th17 and B cells in neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a CNS autoimmune inflammatory disease mediated by T helper 17 (Th17) and antibody responses to the water channel protein, aquaporin 4 (AQP4), and associated with astrocytopathy, demyelination and axonal loss. Knowledge about disease pathogenesis is limited and the search for new therapies impeded by the absence of a reliable animal model. In our work, we determined that NMOSD is characterized by decreased IFN-γ receptor signalling and that IFN-γ depletion in AQP4201-220-immunized C57BL/6 mice results in severe clinical disease resembling human NMOSD. Pathologically, the disease causes autoimmune astrocytic and CNS injury secondary to cellular and humoral inflammation. Immunologically, the absence of IFN-γ allows for increased expression of IL-6 in B cells and activation of Th17 cells, and generation of a robust autoimmune inflammatory response. Consistent with NMOSD, the experimental disease is exacerbated by administration of IFN-β, whereas repletion of IFN-γ, as well as therapeutic targeting of IL-17A, IL-6R and B cells, ameliorates it. We also demonstrate that immune tolerization with AQP4201-220-coupled poly(lactic-co-glycolic acid) nanoparticles could both prevent and effectively treat the disease. Our findings enhance the understanding of NMOSD pathogenesis and provide a platform for the development of immune tolerance-based therapies, avoiding the limitations of the current immunosuppressive therapies.

Risks and outcomes of pregnancy in neuromyelitis optica spectrum disorder: A comprehensive review

Neuromyelitis optica spectrum disorder (NMOSD) is a rare central nervous system autoimmune disease. Aquaporin-4 antibody (AQP4-IgG) is present in over 75% of cases and criteria also exist for the diagnosis of seronegative NMOSD. AQP4-IgG NMOSD has a strong female predominance (9:1 ratio), with a median onset age of 40 years. Pregnancy in those with NMOSD is therefore an important topic. Fecundity in NMOSD is likely impaired, and for females who conceive, obstetric complications including miscarriages and pre-eclampsia are significantly higher in NMOSD compared to the general population and in related conditions such as multiple sclerosis (MS). In contrast to MS, NMOSD disease activity does not subside during pregnancy. Also, relapse risk substantially rises above pre-pregnancy rates in the early postpartum period. In view of the evolving landscape of NMOSD, we provide a contemporary update of the impacts of pregnancy in NMOSD.

Expression analysis of Treg-related lncRNAs in neuromyelitis optica spectrum disorder

Neuromyelitis Optica Spectrum Disorder (NMOSD) is an autoimmune condition affecting the central nervous system, in which various kinds of immune cells, including T and B cells, and numerous cytokines and chemokines are implicated. LncRNAs modulating the function or differentiation of regulatory T cells (Tregs) may be involved in the pathoetiology of NMO. To assess the involvement of these lncRNAs in this disease, we studied the expression levels of TH2-LCR, MAFTRR, NEST, RMRP, and FLICR in NMO patients and healthy subjects. All of the lncRNAs listed were up-regulated in NMO patients compared with healthy controls. Although the interaction of group and gender factors significantly affected the expression of NEST, RMRP, and TH2-LCR genes, we detected no effect of gender factor on the expression of the examined genes. The highest expression correlation was found between RMRP and TH2-LCR among cases with correlation coefficient 0.73. ROC curve analysis indicated that TH2-LCR, MAFTRR, RMRP, and FLICR had significant prospective diagnostic power (AUC ± SD = 0.99 ± 0.002, 0.97 ± 0.01, 0.91 ± 0.01 and 0.84 ± 0.04, respectively). Best of these genes was TH2-LCR with AUC ± SD = 0.99 ± 0.002, sensitivity= 0.97, specificity= 1, P-value= <0.0001. RMRP and TH2-LCR had a positive correlation with age and age at onset and a negative correlation with EDSS. Cumulatively, TH2-LCR, MAFTRR, RMRP, and FLICR lncRNAs, particularly TH2-LCR, could be considered as potential contributors to the pathogenesis of NMO disease.

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.

Significant up-regulation of lncRNAs in neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is an immune-related demyelinating defect. Long non-coding RNAs (lncRNAs) might influence the pathobiology and progression of NMOSD. The current study assessed expression level of NEAT1, PANDAR, MEG3 and TUG1 lncRNAs in the peripheral blood of NMOSD patients compared with healthy individuals. All mentioned lncRNAs were shown to be over-expressed in total NMOSD cases, male NMOSD cases and female NMOSD cases compared with the matching control subgroups. MEG3 had the most robust over-expression in patients subgroups compared with normal subjects. There was no noteworthy difference in the expression of any of lncRNAs between female and male patients. MEG3 had an ideal performance in the differentiation of NMOSD cases from healthy persons (Sensitivity and specificity values = 100%). Other lncRNAs could also efficiently separate NMOSD cases from control subjects (AUC values = 0.97, 0.89 and 0.88 for PANDAR, NEAT1 and TUG1, respectively). Cumulatively, NEAT1, PANDAR, MEG3 and TUG1 lncRNAs can be considered as appropriate disease markers for NMOSD.

Genome-Wide Expression Profile in People with Optic Neuritis Associated with Multiple Sclerosis

The aim of this study was to perform a genome-wide expression analysis of whole-blood samples from people with optic neuritis (ON) and to determine differentially expressed mRNAs compared to healthy control subjects. The study included eight people with acute ON and six healthy control subjects. Gene expression was analyzed using DNA microarrays for whole-human-genome analysis, which contain 54,675 25-base pairs. The additional biostatistical analysis included gene ontology analysis and gene set enrichment analysis (GSEA). Quantitative RT-PCR (qPCR) was used to confirm selected differentially expressed genes. In total, 722 differently expressed genes were identified, with 377 exhibiting increased, and 345 decreased, expression. Gene ontology analysis and GSEA revealed that protein phosphorylation and intracellular compartment, apoptosis inhibition, pathways involved in cell cycles, T and B cell functions, and anti-inflammatory central nervous system (CNS) pathways are implicated in ON pathology. qPCR confirmed the differential expression of eight selected genes, with SLPI, CR3, and ITGA4 exhibiting statistically significant results. In conclusion, whole-blood gene expression analysis showed significant differences in the expression profiles of people with ON compared to healthy control subjects. Additionally, pathways involved in T cell regulation and anti-inflammatory pathways within CNS were identified as important in the early phases of MS.

Genetic Basis of Inflammatory Demyelinating Diseases of the Central Nervous System: Multiple Sclerosis and Neuromyelitis Optica Spectrum

Demyelinating diseases alter myelin or the coating surrounding most nerve fibers in the central and peripheral nervous systems. The grouping of human central nervous system demyelinating disorders today includes multiple sclerosis (MS) and neuromyelitis optica spectrum disorders (NMOSD) as distinct disease categories. Each disease is caused by a complex combination of genetic and environmental variables, many involving an autoimmune response. Even though these conditions are fundamentally similar, research into genetic factors, their unique clinical manifestations, and lesion pathology has helped with differential diagnosis and disease pathogenesis knowledge. This review aims to synthesize the genetic approaches that explain the differential susceptibility between these diseases, explore the overlapping clinical features, and pathological findings, discuss existing and emerging hypotheses on the etiology of demyelination, and assess recent pathogenicity studies and their implications for human demyelination. This review presents critical information from previous studies on the disease, which asks several questions to understand the gaps in research in this field.

Familial neuromyelitis optica spectrum disorders: Case series and systematic review

BACKGROUND

Neuromyelitis optica spectrum disorders (NMOSD) is considered a complex multifactorial disorder. Most cases are sporadic, and familial NMOSD is assumed as a rare occurrence. However, few studies reported familial aggregation of the disorder.

OBJECTIVES

To report familial NMOSD cases in Thailand and conduct a systematic review of familial NMOSD.

METHODS

A retrospective chart review of familial NMOSD patients at the university hospital was performed. Articles related to "genetic" and "NMOSD" were systematically searched and reviewed. We included NMOSD patients whose one or more relatives were diagnosed with the same disease or multiple sclerosis (MS). Data regarding demographics, clinical features, disease outcomes, and genetic testing were collected and analyzed using descriptive statistics.

RESULTS

We identified 6 familial cases from 165 NMOSD cases (3.6%) at our hospital and gathered 77 cases from a systematic review, totaling 83 cases from 40 families. The mean (SD) age at onset was 37.2 (18.0) years. Familial NMOSD involved 1-2 generations with mainly 2 affected individuals. The most common kinship pattern was siblingship in 21 families (52.5%). Initial syndromes were mostly optic neuritis and transverse myelitis. Serum aquaporin-4 IgG was positive in 79.7% of cases. Median number of relapses was 3 (range 1-26). Median expanded disability status scale in the last visit was 2 (range 0-8). Reported human leukocyte antigens (HLA) alleles shared between familial cases were HLA-A*01 and HLA-DRB1*03.

CONCLUSION

Familial clustering of NMOSD is more common than would be expected in the general population. The demographic, clinical, and outcome profiles of familial cases were not different from sporadic cases. Certain specific HLA haplotypes were shared among familial cases. Our systematic review highlighted complex genetic predisposition to NMOSD.

Therapeutic efficacy and safety of plasmapheresis in elderly patients with neuromyelitis optica spectrum disorder: a single-center observational study

Background

Neuromyelitis optica spectrum disorder (NMOSD) is a devastating autoimmune disorder with cycles of escalating relapse. Rates of diagnosis in the elderly are increasing. Therapeutic decision-making is more challenging in elderly patients due to multiple comorbidities and high risk of drug-induced side effects.

Objective

This retrospective study assessed the efficacy and safety of standard plasma exchange (PLEX) treatment in an elderly population with NMOSD.

Design

Seventy-six patients with NMOSD who received PLEX were apportioned to two groups as either elderly (⩾60 years, n = 26) or young (<60 years) at the time of the first procedure.

Methods

Therapeutic response was judged according to functional recovery at 6 months, as reflected by Expanded Disability Status Scale (EDSS) and visual outcome scale (VOS) scores.

Results

The mean age of the 26 elderly patients was 67.7 ± 7.9 years (range 60-87 years); the population was predominantly female (88.5%). PLEX sessions were generally well tolerated among the elderly. Compared with the young patients, the elderly had significantly more comorbidities and concomitant medications. Twenty-four (96.0%) elderly patients showed functional improvement at 6 months after PLEX, of which 15 (60.0%) experienced moderate-to-marked improvement. Six months after the initial PLEX treatment, the patients overall experienced a significant improvement in EDSS and VOS scores. Logistic regression showed that severe optic neuritis attack was a significant independent prognostic factor associated with poor PLEX response. The groups were comparable regarding overall or serious adverse events. The rate of transient hypotension was significantly higher in the elderly compared with the young.

Conclusion

PLEX is an effective and safe therapy for elderly patients with NMOSD and should be considered a treatment option during NMOSD attacks. In the elderly, preventive measures against hypotension are recommended before PLEX.

Clinical and genetic analysis of familial neuromyelitis optica spectrum disorder in Chinese: associated with ubiquitin-specific peptidase USP18 gene variants

BACKGROUND

Familial clustering of neuromyelitis optica spectrum disorder (NMOSD) was present in Chinese. This study was to investigate the clinical characteristics and genetic background of familial NMOSD.

METHODS

Through questionnaires in four medical centres in 2016-2020, we identified 10 families with NMOSD aggregation. The statistical differences of clinical characteristics between familial and sporadic NMOSD (22 cases and 459 cases) were summarised. The whole-exome sequencing (WES) for seven families (13 cases and 13 controls) was analysed, compared with our previous WES data for sporadic NMOSD (228 cases and 1 400 controls). The family-based and population-based association and linkage analysis were conducted to identify the pathogenetic genes, the variant impacts were predicted.

RESULTS

The familial occurrence was 0.87% in Chinese. Familial patients had higher expanded disability status scale score than sporadic patients (p=0.03). The single-nucleotide polymorphism (SNP) rs2252257 in the promoter and enhancer of ubiquitin-specific peptidase USP18 was linked to familial NMOSD (p=7.8E-05, logarithm of the odds (LOD)=3.1), SNPs rs361553, rs2252257 and rs5746523 were related to sporadic NMOSD (p=1.29E-10, 3.45E-07 and 2.01E-09, respectively). Patients with the SNP rs361553 T/T genotype had higher recurrence rate than C/T or C/C genotype (1.22±0.85 vs 0.69±0.57 and 0.81±0.65, p=0.003 and 0.001, respectively). SNPs rs361553 and rs2252257 altered USP18 expression in brain and nerve tissues.

CONCLUSION

Most clinical characteristics of familial NMOSD were indistinguishable from sporadic NMOSD except for the worst episodes severity. USP18 with impaired intronic regulatory function contributed to the pathogenesis of NMOSD.

Sex and gender differences in autoimmune demyelinating CNS disorders: Multiple sclerosis (MS), neuromyelitis optica spectrum disorder (NMOSD) and myelin-oligodendrocyte-glycoprotein antibody associated disorder (MOGAD)

Multiple sclerosis (MS), Neuromyelitis optica spectrum disorder (NMOSD) and Myelin-Oligodendrocyte-Glycoprotein antibody associated disorder (MOGAD) are demyelinating disorders of the central nervous system (CNS) of autoimmune origin. Here, we summarize general considerations on sex-specific differences in the immunopathogenesis and hormonal influences as well as key clinical and epidemiological elements. Gender-specific issues are widely neglected starting with the lacking separation of sex as a biological variable and gender comprising the sociocultural components. As for other autoimmune diseases, female preponderance is common in MS and NMOSD. However, sex distribution in MOGAD seems equal. As in MS, immunotherapy in NMOSD and MOGAD is crucial to prevent further disease activity. Therefore, we assessed data on sex differences of the currently licensed disease-modifying treatments for efficacy and safety. This topic seems widely neglected with only fragmented information resulting from post-hoc analyses of clinical trials or real-world post-marketing studies afflicted with lacking power and/or inherent sources of bias. In summary, biological hypotheses of sex differences including genetic factors, the constitution of the immune system and hormonal influences are based upon human and preclinical data, especially for the paradigmatic disease of MS whereas specific data for NMOSD and MOGAD are widely lacking. Epidemiological and clinical differences between men and women are well described for MS and to some extent for NMOSD, yet, with remaining contradictory findings. MOGAD needs further detailed investigation. Sex-specific analyses of safety and efficacy of long-term immunotherapies need to be addressed in future studies designed and powered to answer the pressing questions and to optimize and individualize treatment.

Association between infections, the microbiome, vaccination, and neuromyelitis optica spectrum disorder

Neuromyelitis optica spectrum disorder (NMOSD) is a devastating antibody-mediated condition of the central nervous system. As in other autoimmune diseases, there is considerable evidence to suggest that NMOSD arises from complex interactions between genetic susceptibility and environmental factors. However, whether factors like aquaporin-4-Antibody production initiate NMOSD attacks, currently remains unclear, and requires further investigation. Infectious diseases have also been proposed as possible environmental factors associated with NMOSD onset or relapses, some of which are more common in Asia and Latin America than in Europe and North America, in parallel with the higher incidence of NMOSD in these geographic locations. In this review, we examine current evidence on specific infections and vaccines associated with NMOSD onset and/or attacks, as well as the most recent data on gut microbiome composition and SARS-CoV-2 infection in NMOSD patients.

Neuromyelitis Optica Spectrum Disorder: From Basic Research to Clinical Perspectives

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disease of the central nervous system characterized by relapses and autoimmunity caused by antibodies against the astrocyte water channel protein aquaporin-4. Over the past decade, there have been significant advances in the biologic knowledge of NMOSD, which resulted in the IDENTIFICATION of variable disease phenotypes, biomarkers, and complex inflammatory cascades involved in disease pathogenesis. Ongoing clinical trials are looking at new treatments targeting NMOSD relapses. This review aims to provide an update on recent studies regarding issues related to NMOSD, including the pathophysiology of the disease, the potential use of serum and cerebrospinal fluid cytokines as disease biomarkers, the clinical utilization of ocular coherence tomography, and the comparison of different animal models of NMOSD.