Sex bias in multiple sclerosis and neuromyelitis optica spectrum disorders: How it influences clinical course, MRI parameters and prognosis

Research hotspots and emerging topics in neuromyelitis optica spectrum disorder treatment: Insights from a bibliometric analysis

OBJECT

Effective treatment of neuromyelitis optica spectrum disorder (NMOSD) can greatly reduce the rate of disability and mortality among patients. NMOSD treatment studies are gaining prominence in academic circles. This study aims to depict the evolution and integration of NMOSD treatment over the past 20 years, identify key contributors in the field, clarify current research hotspots, and explore emerging topics that may guide future research directions.

METHOD

Articles in this field from 2004 to 2023 were collected from the Web of Science Core Collection (WoSCC). After conducting a literature search, a comprehensive bibliometric and knowledge mapping analysis was carried out on the retrieved articles using tools such as VOSviewer, Bibliometrix, and CiteSpace.

RESULT

The rapid growth in annual publications in this field indicates rapid progress and innovation. USA, Mayo Clinic, and Fujihara K led in productivity and impact, while the multiple sclerosis and related disorders topped in publication volume. The research hotspots in this field mainly focus on targeted biological agents. Additionally, this study has identified 3 emerging themes and conducted an in-depth exploration of their future development trends.

CONCLUSION

In summary, this bibliometric analysis provides for the first time a comprehensive framework and frontier hot spot analysis in the field of NMOSD treatment, offering references for researchers in the field and contributing to the further development of the field.

Role of Long Non-Coding RNA X-Inactive-Specific Transcript (XIST) in Neuroinflammation and Myelination: Insights from Cerebral Organoids and Implications for Multiple Sclerosis

Background/Objectives: X-inactive-specific transcript (XIST) is a factor that plays a role in neuroinflammation. This study investigated the role of XIST in neuronal development, neuroinflammation, myelination, and therapeutic responses within cerebral organoids in the context of Multiple Sclerosis (MS) pathogenesis. Methods: Human cerebral organoids with oligodendrocytes were produced from XIST-silenced H9 cells, and the mature organoids were subsequently treated with either FTY720 or DMF. Gene expression related to inflammation and myelination was subsequently analyzed via qRT-PCR. Immunofluorescence staining was used to assess the expression of proteins related to inflammation, myelination, and neuronal differentiation. Alpha-synuclein protein levels were also checked via ELISA. Finally, transcriptome analysis was conducted on the organoid samples. Results: XIST-silenced organoids presented a 2-fold increase in the expression of neuronal stem cells, excitatory neurons, microglia, and mature oligodendrocyte markers. In addition, XIST silencing increased IL-10 mRNA expression by 2-fold and MBP and PLP1 expression by 2.3- and 0.6-fold, respectively. Although XIST silencing tripled IBA1 protein expression, it did not affect organoid MBP expression. FTY720, but not DMF, distinguished MBP and IBA1 expression in XIST-silenced organoids. Furthermore, XIST silencing reduced the concentration of alpha-synuclein from 300 to 100 pg/mL, confirming its anti-inflammatory role. Transcriptomic and gene enrichment analyses revealed that the differentially expressed genes are involved in neural development and immune processes, suggesting the role of XIST in neuroinflammation. The silencing of XIST modified the expression of genes associated with inflammation, myelination, and neuronal growth in cerebral organoids, indicating a potential involvement in the pathogenesis of MS. Conclusions: XIST may contribute to the MS pathogenesis as well as neuroinflammatory diseases such as and Alzheimer's and Parkinson's diseases and may be a promising therapeutic target.

Can serum C3/C4 complement ratio be used in the differential diagnosis of central nervous system demyelinating diseases?

BACKGROUND

Neuromyelitis Optica Spectrum Disorders (NMOSD) and Multiple Sclerosis (MS) are primary demyelinating diseases of the central nervous system (CNS) with similar clinical features, complicating early differential diagnosis and treatment decisions. While both humoral and cellular immunity contribute to their immunopathogenesis, the complement system's role remains unclear. We considered complement-dependent cytotoxicity might have different roles in the pathophysiology of these diseases. Predictive value of C3 and C4 complement levels at the first attack for the definitive diagnosis aimed to be investigated.

METHODS

Treatment-naive, 14 seronegative (SN) NMO, 28 aquaporin-4-positive [AQP4(+)] NMO, 23 myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), and 15 MS adult patients were included. Serum C3 and C4 levels were evaluated retrospectively. Complement levels were statistically adjusted according to the age of the patients and C3/C4 ratio was used to increase statistical power.

RESULTS

We found that C4 levels were lower and C3/C4 ratio was higher in SNNMO and AQP4(+)-NMO groups compared to the MS group. It has been determined that 5.32 and 4.85 cut-off values of the C3/C4 ratio can discriminate SNNMO and AQP4(+)-NMO groups from MS.

CONCLUSION

The classical complement pathway in SNNMO and AQP4(+)-NMO was thought to be more affected compared to MS, as activation of the classical pathway predominantly decreases the level of C4. Since the involvement of the complement system pathways at different levels may be presented with the C3/C4 ratio, it seems likely that this ratio may have value as a candidate biomarker in the differential diagnosis of primary CNS demyelinating diseases.

Preferences and attitudes regarding early intervention in multiple sclerosis: A systematic literature review

BACKGROUND

Multiple sclerosis (MS) is a chronic inflammatory disorder affecting the brain and spinal cord, characterized by immune-mediated myelin damage. Early intervention and detection programs have emerged as promising strategies to improve patient outcomes by identifying and treating MS in its earliest stages.

OBJECTIVE

This systematic literature review aims to provide an overview of the preferences, attitudes, and opinions of both patients and healthcare professionals regarding early intervention or early detection programs for MS.

METHODS

A comprehensive search strategy was employed in March 2023 across multiple databases (MEDLINE, Scopus, PsyInfo, PubMed), from 1990 to 2023. A total of 38 articles were selected for analysis based on predefined inclusion and exclusion criteria.

RESULTS

The majority of articles were published in recent years and represented different methods from case reports to randomized controlled trials, with fewer systematic literature reviews. Data collection approaches included patients, healthcare workers, or mixed samples with varying age ranges and gender ratios, frequently preferring women. These samples represented different preference study methods. The included studies were primarily conducted in the USA and the UK. Thematic analysis revealed several key themes : 1) differences emerged between healthcare professionals' and patients' perspectives 2) interventions for MS outside Disease-Modifying Therapies (DMTs) 3) severe side effects 4) communication, information, and knowledge 5) psychological and emotional aspects.

CONCLUSIONS

Understanding these diverse factors and subgroups within the MS population can inform more effective, personalized approaches to MS prevention and treatment.

Biological sex and BMI influence the longitudinal evolution of adolescent and young adult MRI-visible perivascular spaces

Background and Purpose

An association recently emerged between magnetic resonance imaging (MRI)-visible perivascular spaces (MV-PVS) with intracerebral solute clearance and neuroinflammation, in adults. However, it is unknown how MV-PVS change throughout adolescence and what factors influence MV-PVS volume and morphology. This study assesses the temporal evolution of MV-PVS volume in adolescents and young adults, and secondarily evaluates the relationship between MV-PVS, age, sex, and body mass index (BMI).

Materials and Methods

This analysis included a 783 participant cohort from the longitudinal multicenter National Consortium on Alcohol and Neurodevelopment in Adolescence study that involved up to 6 imaging visits spanning 5 years. Healthy adolescents aged 12-21 years at study entry with at least two MRI scans were included. The primary outcome was mean MV-PVS volume (mm 3 /white matter cm 3 ).

Results

On average, males had greater MV-PVS volume at all ages compared to females. A linear mixed-effect model for MV-PVS volume was performed. Mean BMI and increases in a person's BMI were associated with increases in MV-PVS volume over time. In females only, changes in BMI correlated with MV-PVS volume. One unit increase in BMI above a person's average BMI was associated with a 0.021 mm 3 /cm 3 increase in MV-PVS volume (p<0.001).

Conclusion

This longitudinal study showed sex differences in MV-PVS features during adolescence and young adulthood. Importantly, we report that increases in BMI from a person's mean BMI are associated with increases in MV-PVS volume in females only. These findings suggest a potential link between MV-PVS, sex, and BMI that warrants future study.

Prognostic factors of first-onset optic neuritis based on diagnostic criteria and antibody status: a multicentre analysis of 427 eyes

BACKGROUND

Optic neuritis (ON) prognosis is influenced by various factors including attack severity, underlying aetiologies, treatments and consequences of previous episodes. This study, conducted on a large cohort of first ON episodes, aimed to identify unique prognostic factors for each ON subtype, while excluding any potential influence from pre-existing sequelae.

METHODS

Patients experiencing their first ON episodes, with complete aquaporin-4 (AQP4) and myelin oligodendrocyte glycoprotein (MOG) antibody testing, and clinical data for applying multiple sclerosis (MS) diagnostic criteria, were enrolled. 427 eyes from 355 patients from 10 hospitals were categorised into four subgroups: neuromyelitis optica with AQP4 IgG (NMOSD-ON), MOG antibody-associated disease (MOGAD-ON), ON in MS (MS-ON) or idiopathic ON (ION). Prognostic factors linked to complete recovery (regaining 20/20 visual acuity (VA)) or moderate recovery (regaining 20/40 VA) were assessed through multivariable Cox regression analysis.

RESULTS

VA at nadir emerged as a robust prognostic factor for both complete and moderate recovery, spanning all ON subtypes. Early intravenous methylprednisolone (IVMP) was associated with enhanced complete recovery in NMOSD-ON and MOGAD-ON, but not in MS-ON or ION. Interestingly, in NMOSD-ON, even a slight IVMP delay in IVMP by >3 days had a significant negative impact, whereas a moderate delay up to 7-9 days was permissible in MOGAD-ON. Female sex predicted poor recovery in MOGAD-ON, while older age hindered moderate recovery in NMOSD-ON and ION.

CONCLUSION

This comprehensive multicentre analysis on first-onset ON unveils subtype-specific prognostic factors. These insights will assist tailored treatment strategies and patient counselling for ON.

Sex differences in multiple sclerosis relapse presentation and outcome: a retrospective, monocentric study of 134 relapse events

Background

Reporting of sex-specific analyses in multiple sclerosis (MS) is sparse. Disability accrual results from relapses (relapse-associated worsening) and independent thereof (progression independent of relapses).

Objectives

A population of MS patients during relapse treated per standard of care was analyzed for sex differences and short-term relapse outcome (3-6 months) as measured by Expanded Disability Status Scale (EDSS) change.

Design

Single-center retrospective study.

Methods

We analyzed 134 MS relapses between March 2016 and August 2020. All events required relapse treatment (steroids and/or plasma exchange). Demographic, disease, and paraclinical characteristics [cerebrospinal fluid (CSF) and magnetic resonance imaging (MRI)] were displayed separated by sex. Multivariable linear regression was run to identify factors associated with short-term EDSS change.

Results

Mean age at relapse was 38.4 years (95% confidence interval: 36.3-40.4) with a proportion of 71.6% women in our cohort. Smoking was more than twice as prevalent in men (65.8%) than women (32.3%). In- and after-relapse EDSSs were higher in men [men: 3.3 (2.8-3.9), women: 2.7 (2.4-3.0); men: 3.0 (1.3-3.6); women: 1.8 (1.5-2.1)] despite similar relapse intervention. Paraclinical parameters revealed no sex differences. Our primary model identified female sex, younger age, and higher EDSS at relapse to be associated with EDSS improvement. A higher immunoglobulin G (IgG) quotient (CSF/serum) was associated with poorer short-term outcome [mean days between first relapse treatment and last EDSS assessment 130.2 (79.3-181.0)].

Conclusion

Sex and gender differences are important in outcome analyses of MS relapses. Effective treatment regimens need to respect putative markers for a worse outcome to modify long-term prognosis such as clinical and demographic variables, complemented by intrathecal IgG synthesis. Prospective trials should be designed to address these differences and confirm our results.

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.

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.

Gender differences in the burden of multiple sclerosis in China from 1990 to 2019 and its 25-year projection: An analysis of the Global Burden of Diseases Study

Background and Aims

Multiple sclerosis (MS) is a crippling, chronic, gender-related disease that causes burdens to individuals and society. China has a considerable and increasing population of MS. We aim to analyze the gender disparities in the burden of MS in China and predict the trends.

Methods

The study was conducted based on the Global Burden of Disease Study 2019. Data on incidence, prevalence, deaths, and disability-adjusted life years (DALYs) of MS in China from 1990 to 2019 was descriptively analyzed by year, gender, and age group. The Nordpred package in R (version 4.2.2) was used for age-period-cohort analysis to predict the all-ages numbers and age-standardized rates of incidence, prevalence, deaths, and DALYs in China from 2020 to 2044.

Results

The number of prevalent cases of MS in 2019 reached 18,143.56 (95% uncertainty intervals [UI]: 13,997.71-22,658.60) in males and 24,427.11 (95% UI: 18,906.02-30,530.21) in females in China. The peak age of prevalence was shifted from 40-44 years in 1990 to 45-49 years in 2019 in females but remained unchanged in males. In contrast to the increased age-standardized prevalence rate, the age-standardized death rate (ASDR) and age-standardized DALYs rate showed downward trends, which were more significant in females. Different from the global, Chinese males showed lower prevalence but higher deaths and DALYs than females for age-standardized rates and numbers. In the next 25 years, the patient population will remain large and peak around 44,599.78 in 2025-2029. The ASDR, age-standardized DALYs rate, and DALYs number were expected to decrease. The improvements in deaths and DALYs will be more significant in females.

Conclusion

Males with MS had a lower prevalence but higher deaths and DALYs than females in China. The ASDR and age-standardized DALYs rate have reduced over the past 30 years and were expected to continue decreasing, especially in females. The burden of MS will remain notable in the next 25 years.

B-cell activating factor gene variants in multiple sclerosis: Possible associations with disease susceptibility among females

Although B cells and B cell activating factor (BAFF) have been previously implicated in MS pathogenesis, data regarding the genetic influence of BAFF polymorphisms on MS susceptibility are limited. Here we aim to explore whether BAFF polymorphisms could contribute to MS susceptibility. 156 RRMS patients fulfilling the revised McDonald criteria for MS diagnosis and 220 HCs were enrolled. Clinical, laboratory, and imaging characteristics were recorded. BAFF rs9514827, rs1041569, and rs9514828 polymorphisms were assessed by RFLP-PCR in DNA samples extracted from whole peripheral blood. The BAFF rs1041569 TT genotype along with the CTT and TTC haplotypes were associated with significantly increased risk for MS development in female MS patients compared to healthy female counterparts. These findings were not confirmed in males. The rs1041569 BAFF variant together with the CTT and TTC BAFF haplotypes derived from the BAFF rs9514827, rs1041569, and rs9514828 polymorphisms may represent novel genetic contributors to the development of MS in females.

Neuromyelitis Optica Spectrum Disorder with Sick Sinus Syndrome: Two Cases and a Literature Review

BACKGROUND AND OBJECTIVE

Neuromyelitis optica spectrum disorder (NMOSD) is a rare immune-mediated demyelinating disease of the central nervous system (CNS). There is a lack of reports of sick sinus syndrome (SSS) associated with NMOSD; thus, we hereby report two cases of patients with NMOSD who developed SSS.

CASES PRESENTATION

The patients were both male and presented with area postrema syndrome. Brain MRI showed lesions in the dorsal part of their medulla oblongata. They were diagnosed with NMOSD when aquaporin-4 antibodies were found in their serum. Slow heart rates and several episodes of syncope were also observed in case 1 during hospitalization, while Holter monitoring showed sinus pauses (10-11 s) and SSS was diagnosed. A pacemaker was fitted. Case 2 had a respiratory arrest followed by a subsequent cardiac arrest. He was successfully resuscitated with epinephrine injection and cardiopulmonary resuscitation. Through immunotherapy, their neurological functions became stable and heart rate and blood pressure returned to the baseline.

CONCLUSIONS

Since sick sinus syndrome is a life-threatening complication, serious heart arrhythmias should be considered as a potential result of area postrema syndrome associated with NMOSD.

Sex and Gender Differences in Neurodegenerative Diseases: Challenges for Therapeutic Opportunities

The term "neurodegenerative diseases" (NDs) identifies a group of heterogeneous diseases characterized by progressive loss of selectively vulnerable populations of neurons, which progressively deteriorates over time, leading to neuronal dysfunction. Protein aggregation and neuronal loss have been considered the most characteristic hallmarks of NDs, but growing evidence confirms that significant dysregulation of innate immune pathways plays a crucial role as well. NDs vary from multiple sclerosis, in which the autoimmune inflammatory component is predominant, to more "classical" NDs, such as Parkinson's disease, Alzheimer's disease, amyotrophic lateral sclerosis, and spinal muscular atrophy. Of interest, many of the clinical differences reported in NDs seem to be closely linked to sex, which may be justified by the significant changes in immune mechanisms between affected females and males. In this review, we examined some of the most studied NDs by looking at their pathogenic and phenotypical features to highlight sex-related discrepancies, if any, with particular interest in the individuals' responses to treatment. We believe that pointing out these differences in clinical practice may help achieve more successful precision and personalized care.

Structural and functional brain damage in women with multiple sclerosis: A mini-review of neuroimaging sex-based studies

Neuroimaging literature in healthy humans has shown that there are sex-related differences in healthy brain's anatomical structure, associated function and susceptibility to neurological diseases. This mini-review summarizes findings derived from the current neuroimaging studies focused on sex-related brain structural and functional damage in women with multiple sclerosis (MS). MS is a chronic, multifactorial, immune-mediated disorder of the central nervous system that affects mostly women. Even if recent neuroimaging studies have shed light on distinctive features of sex-related MS differences in brain structural and functional damage, more research is needed to better elucidate sex-related MS pathological changes and susceptibility and to implement sex-tailored treatment strategies in MS.