Low intensity repetitive transcranial magnetic stimulation enhances remyelination by newborn and surviving oligodendrocytes in the cuprizone model of toxic demyelination.

In people with multiple sclerosis (MS), newborn and surviving oligodendrocytes (OLs) can contribute to remyelination, however, current therapies are unable to enhance or sustain endogenous repair. Low intensity repetitive transcranial magnetic stimulation (LI-rTMS), delivered as an intermittent theta burst stimulation (iTBS), increases the survival and maturation of newborn OLs in the healthy adult mouse cortex, but it is unclear whether LI-rTMS can promote remyelination. To examine this possibility, we fluorescently labelled oligodendrocyte progenitor cells (OPCs; Pdgfrα-CreER transgenic mice) or mature OLs (Plp-CreER transgenic mice) in the adult mouse brain and traced the fate of each cell population over time. Daily sessions of iTBS (600 pulses; 120 mT), delivered during cuprizone (CPZ) feeding, did not alter new or pre-existing OL survival but increased the number of myelin internodes elaborated by new OLs in the primary motor cortex (M1). This resulted in each new M1 OL producing ~ 471 µm more myelin. When LI-rTMS was delivered after CPZ withdrawal (during remyelination), it significantly increased the length of the internodes elaborated by new M1 and callosal OLs, increased the number of surviving OLs that supported internodes in the corpus callosum (CC), and increased the proportion of axons that were myelinated. The ability of LI-rTMS to modify cortical neuronal activity and the behaviour of new and surviving OLs, suggests that it may be a suitable adjunct intervention to enhance remyelination in people with MS.

Significantly increasing multiple sclerosis prevalence in Australia from 2010 to 2021.

BACKGROUND: Multiple sclerosis (MS) prevalence is increasing globally. OBJECTIVES: To determine whether increased prevalence is continuing within Australia using our validated prescription-based ascertainment method. METHODS: We used methods employed in our 2010 and 2017 prevalence estimates. Disease-modifying therapy (DMT) prescriptions were extracted from Australia's Pharmaceutical Benefits Scheme data for January-December 2021. DMT penetrance was calculated using data from the Australian MS Longitudinal Study. We divided the total number of monthly prescriptions by 12 or 2 (except alemtuzumab), adjusted for DMT penetrance and Australian population estimates. Prevalences in Australian states/territories were age-standardised. 2021 prevalence estimates were compared with 2010 and 2017 prevalence estimates using Poisson regression. RESULTS: Number of people with MS in Australia in 2021 was 33,335; an increase of 7728 from 2017 (30.2%) and 12,092 from 2010 (56.6%) and increasing at a faster rate than population change (+10.1%, +14.1%). Age-standardised prevalence was 136.1/100,000 (increased from 103.7/100,000 in 2017). The previously demonstrated positive latitudinal gradient in 2010 and 2017 persisted in 2021, with Tasmania (southernmost state) having the highest prevalence (age-standardised: 203.5/100,000) while northernmost states had the lowest. CONCLUSIONS: In line with global trends, MS prevalence is escalating in Australia, particularly in higher-latitude states. MS prevention is crucial to halt this disturbing trend.

Estimation of Transition Probabilities from a Large Cohort (> 6000) of Australians Living with Multiple Sclerosis (MS) for Changing Disability Severity Classifications, MS Phenotype, and Disease-Modifying Therapy Classifications.

BACKGROUND: Multiple sclerosis (MS) is a chronic autoimmune/neurodegenerative disease associated with progressing disability affecting mostly women. We aim to estimate transition probabilities describing MS-related disability progression from no disability to severe disability. Transition probabilities are a vital input for health economics models. In MS, this is particularly relevant for pharmaceutical agency reimbursement decisions for disease-modifying therapies (DMTs). METHODS: Data were obtained from Australian participants of the MSBase registry. We used a four-state continuous-time Markov model to describe how people with MS transition between disability milestones defined by the Expanded Disability Status Scale (scale 0-10): no disability (EDSS of 0.0), mild (EDSS of 1.0-3.5), moderate (EDSS of 4.0-6.0), and severe (EDSS of 6.5-9.5). Model covariates included sex, DMT usage, MS-phenotype, and disease duration, and analysis of covariate groups were also conducted. All data were recorded by the treating neurologist. RESULTS: A total of N = 6369 participants (mean age 42.5 years, 75.00% female) with 38,837 person-years of follow-up and 54,570 clinical reviews were identified for the study. Annual transition probabilities included: remaining in the no, mild, moderate, and severe states (54.24%, 82.02%, 69.86%, 77.83% respectively) and transitioning from no to mild (42.31%), mild to moderate (11.38%), and moderate to severe (9.41%). Secondary-progressive MS was associated with a 150.9% increase in the hazard of disability progression versus relapsing-remitting MS. CONCLUSIONS: People with MS have an approximately 45% probability of transitioning from the no disability state after one year, with people with progressive MS transitioning from this health state at a much higher rate. These transition probabilities will be applied in a publicly available health economics simulation model for Australia and similar populations, intended to support reimbursement of a plethora of existing and upcoming interventions including medications to reduce progression of MS.

The association of comorbidities with sleep quality among Australians with multiple sclerosis: Insights from the Australian Multiple Sclerosis Longitudinal Study.

BACKGROUND: Comorbidities and poor sleep quality are prevalent among individuals with multiple sclerosis (MS). Our understanding of the effects of comorbidities on sleep quality in MS remains limited. OBJECTIVES: The objectives were to investigate whether the number and presence of specific comorbidities have associations with sleep quality and to assess the relative contribution of comorbidity groups to sleep quality. METHODS: We collected data on sleep quality (using Pittsburgh Sleep Quality Index (PSQI)) and presence of comorbidities in people with MS (n = 1597). Associations between comorbidities and sleep quality were examined using linear regression and dominance analysis. RESULTS: Having more comorbidities was associated with poorer sleep quality (p for trend < 0.001). All 13 groups of comorbidities explained 12.9% of the variance in PSQI from which half of the variance was contributed by mental health disorders. In total, 16 of the 28 comorbidities were associated with significantly worse sleep quality, with the strongest associations seen for 'other autoimmune diseases' (ß = 1.98), depression (ß = 1.76), anxiety (ß = 1.72) and rheumatoid arthritis (ß = 1.62). CONCLUSIONS: Many individual comorbidities are associated with poorer sleep quality, with mental health disorders making the largest relative contribution. Optimal management of comorbidities that make the greatest contributions could have the largest benefit for improving sleep in MS.

Protocol for a pragmatic randomised controlled feasibility study of MS WorkSmart: an online intervention for Australians with MS who are employed.

INTRODUCTION: Multiple sclerosis (MS) causes a wide variety of symptoms. Loss of income due to sickness and early retirement comprise one-third of the total cost of MS in Australia. An intervention that maximises work productivity and keeps people with MS in the workforce for longer could provide a large societal cost saving and improve quality of life. The aim is to test the feasibility of delivering and evaluating a 10-week digitally delivered intervention called 'MS WorkSmart'. Findings will provide insights into participant profiles and address key methodological and procedural uncertainties (recruitment, retention, intervention adherence and engagement, and selection of primary outcome) in preparation for a subsequent definitive trial. METHODS AND ANALYSIS: A parallel-arm randomised controlled feasibility study, comparing those randomised to receive the MS WorkSmart package plus usual care (n=20) to those receiving usual care only (n=20). Australians with MS, aged 18-60 years, who are employed, and self-report work instability will be recruited from the Australian MS Longitudinal Study. Online surveys, at baseline and 1-month postintervention, will include MS-related work productivity loss and risk of job loss, MS work behaviour self-efficacy, health-related quality of life, fatigue severity, MS symptom impact on work, intention to retire due to MS, MS-related work difficulties, and awareness and readiness for change at work. Qualitative feedback will be obtained via a semistructured survey following the intervention (for participants) and via interviews (coaches). Analyses will be primarily descriptive and focus on the feasibility and acceptability of the intervention and study procedures. Progression criteria will guide decisions around whether to progress to a full trial. ETHICS AND DISSEMINATION: The study has been approved by the University of Tasmania Human Research Ethics Committee (H0024544). Findings will be disseminated via publication in peer-reviewed journals, conference presentations and community presentations. TRIAL REGISTRATION NUMBER: ACTRN12622000826741.

Low-intensity repetitive transcranial magnetic stimulation is safe and well tolerated by people living with MS - outcomes of the phase I randomised controlled trial (TAURUS).

Background: Low-intensity repetitive transcranial magnetic stimulation (rTMS), delivered as a daily intermittent theta burst stimulation (iTBS) for four consecutive weeks, increased the number of new oligodendrocytes in the adult mouse brain. Therefore, rTMS holds potential as a remyelinating intervention for people with multiple sclerosis (MS). Objective: Primarily to determine the safety and tolerability of our rTMS protocol in people with MS. Secondary objectives include feasibility, blinding and an exploration of changes in magnetic resonance imaging (MRI) metrics, patient-reported outcome measures (PROMs) and cognitive or motor performance. Methods: A randomised (2:1), placebo controlled, single blind, parallel group, phase 1 trial of 20 rTMS sessions (600 iTBS pulses per hemisphere; 25% maximum stimulator output), delivered over 4-5 weeks. Twenty participants were randomly assigned to 'sham' (n = 7) or active rTMS (n = 13), with the coil positioned at 90° or 0°, respectively. Results: Five adverse events (AEs) including one serious AE reported. None were related to treatment. Protocol compliance was high (85%) and blinding successful. Within participant MRI metrics, PROMs and cognitive or motor performance were unchanged over time. Conclusion: Twenty sessions of rTMS is safe and well tolerated in a small group of people with MS. The study protocol and procedures are feasible. Improvement of sham is warranted before further investigating safety and efficacy.

The quality of life impact of the COVID-19 pandemic and lockdowns for people living with multiple sclerosis (MS): evidence from the Australian MS Longitudinal Study.

PURPOSE: People living with multiple sclerosis (PwMS) in metropolitan Victoria, Australia, experienced a 112-day, COVID-19-related lockdown in mid-2020. Contemporaneously, Australian PwMS elsewhere experienced minimal restrictions, resulting in a natural experiment. This study investigated the relationships between lockdowns, COVID-19-related adversity, and health-related quality of life (HRQoL). It also generated health state utilities (HSU) representative of changes in HRQoL. METHODS: Data were extracted from Australian MS Longitudinal Study surveys, which included the Assessment of Quality of Life-Eight Dimensions (AQoL-8D) instrument and a COVID-19 questionnaire. This COVID-19 questionnaire required participants to rank their COVID-19-related adversity across seven health dimensions. Ordered probits were used to identify variables contributing to adversity. Linear and logit regressions were applied to determine the impact of adversity on HRQoL, defined using AQoL-8D HSUs. Qualitative data were examined thematically. RESULTS: N = 1666 PwMS (average age 58.5; 79.8% female; consistent with the clinical presentation of MS) entered the study, with n = 367 (22.0%) exposed to the 112-day lockdown. Lockdown exposure and disability severity were strongly associated with higher adversity rankings (p < 0.01). Higher adversity rankings were associated with lower HSUs. Participants reporting major adversity, across measured health dimensions, had a mean HSU 0.161 (p < 0.01) lower than participants reporting no adversity and were more likely (OR: 2.716, p < 0.01) to report a clinically significant HSU reduction. Themes in qualitative data supported quantitative findings. CONCLUSIONS: We found that COVID-19-related adversity reduced the HRQoL of PwMS. Our HSU estimates can be used in health economic models to evaluate lockdown cost-effectiveness for people with complex and chronic (mainly neurological) diseases.

No evidence for association between rs10191329 severity locus and longitudinal disease severity in 1813 relapse-onset multiple sclerosis patients from the MSBase registry.

BACKGROUND: The International Multiple Sclerosis Genetics Consortium and MultipleMS Consortium recently reported a genetic variant associated with multiple sclerosis (MS) severity. However, it remains unclear if these variants remain associated with more robust, longitudinal measures of disease severity. METHODS: We examined the top variant, rs10191329, from Harroud et al.'s study in 1813 relapse-onset MS patients from the MSBase Registry to assess association with longitudinal disease severity. RESULTS: Our analysis revealed no significant association between rs10191329 genotype and longitudinal binary disease severity (p > 0.05). CONCLUSION: These findings highlight the complexity of genetic factors mediating long-term MS outcomes and the need for further research.

Self-reported behaviour change among multiple sclerosis community members and interested laypeople 6 months following participation in a free online course about multiple sclerosis.

ISSUE ADDRESSED: Evaluated the impact of the Understanding Multiple Sclerosis (MS) massive open online course, which was intended to increase understanding and awareness about MS, on self-reported health behaviour change 6 months after course completion. METHODS: Observational cohort study evaluating precourse(baseline) and postcourse (immediately postcourse and six-month follow-up) survey data. The main study outcomes were self-reported health behaviour change; change type; and measurable improvement. We also collected participant characteristic data (eg, age, physical activity). We compared participants who reported health behaviour change at follow-up to those who did not and compared those who improved to those who did not using χ2 and t tests. Participant characteristics, change types and change improvement were described descriptively. Consistency between changes reported immediately postcourse and at the 6-month follow-up was assessed using χ2 tests and textual analysis. RESULTS: N = 303 course completers were included in this study. The study cohort included MS community members (eg, people with MS, healthcare providers) and nonmembers. N = 127 (41.9%) reported behaviour change in ≥1 area at follow-up. Of these, 90 (70.9%) reported a measured change, and of these, 57 (63.3%) showed improvement. The most reported change types were knowledge, exercise/physical activity and diet. N = 81 (63.8% of those reporting a change) reported a change in both immediately and 6 months after course completion, with 72.0% of those that described both changes giving similar responses each time. CONCLUSION: Understanding MS encourages health behaviour change among course completers up to 6 months after course completion. SO WHAT?: An online education intervention can effectively encourage health behaviour change over a 6-month follow-up period, suggesting a transition from acute change to maintenance. The primary mechanisms underpinning this effect are information provision, including both scientific evidence and lived experience, and goal-setting activities and discussions.

Exploring the cost-effectiveness of EBV vaccination to prevent multiple sclerosis in an Australian setting.

BACKGROUND: Increasing evidence suggests the potential of Epstein-Barr virus (EBV) vaccination in preventing multiple sclerosis (MS). We aimed to explore the cost-effectiveness of a hypothetical EBV vaccination to prevent MS in an Australian setting. METHODS: A five-state Markov model was developed to simulate the incidence and subsequent progression of MS in a general Australian population. The model inputs were derived from published Australian sources. Hypothetical vaccination costs, efficacy and strategies were derived from literature. Total lifetime costs, quality-adjusted life years (QALYs) and incremental cost-effectiveness ratios (ICERs) were estimated for two hypothetical prevention strategies versus no prevention from the societal and health system payer perspectives. Costs and QALYs were discounted at 5% annually. One-way, two-way and probabilistic sensitivity analyses were performed. RESULTS: From societal perspective, EBV vaccination targeted at aged 0 and aged 12 both dominated no prevention (ie, cost saving and increasing QALYs). However, vaccinating at age 12 was more cost-effective (total lifetime costs reduced by $A452/person, QALYs gained=0.007, ICER=-$A64 571/QALY gained) than vaccinating at age 0 (total lifetime costs reduced by $A40/person, QALYs gained=0.003, ICER=-$A13 333/QALY gained). The probabilities of being cost-effective under $A50 000/QALY gained threshold for vaccinating at ages 0 and 12 were 66% and 90%, respectively. From health system payer perspective, the EBV vaccination was cost-effective at age 12 only. Sensitivity analyses demonstrated the cost-effectiveness of EBV vaccination to prevent MS under a wide range of plausible scenarios. CONCLUSIONS: MS prevention using future EBV vaccinations, particularly targeted at adolescence population, is highly likely to be cost-effective.

Vitamin D did not reduce multiple sclerosis disease activity after a clinically isolated syndrome.

Low serum levels of 25-hydroxyvitamin D [25(OH)D] and low sunlight exposure are known risk factors for the development of multiple sclerosis. Add-on vitamin D supplementation trials in established multiple sclerosis have been inconclusive. The effects of vitamin D supplementation to prevent multiple sclerosis is unknown. We aimed to test the hypothesis that oral vitamin D3 supplementation in high-risk clinically isolated syndrome (abnormal MRI, at least three T2 brain and/or spinal cord lesions), delays time to conversion to definite multiple sclerosis, that the therapeutic effect is dose-dependent, and that all doses are safe and well tolerated. We conducted a double-blind trial in Australia and New Zealand. Eligible participants were randomized 1:1:1:1 to placebo, 1000, 5000 or 10 000 international units (IU) of oral vitamin D3 daily within each study centre (n = 23) and followed for up to 48 weeks. Between 2013 and 2021, we enrolled 204 participants. Brain MRI scans were performed at baseline, 24 and 48 weeks. The main study outcome was conversion to clinically definite multiple sclerosis based on the 2010 McDonald criteria defined as either a clinical relapse or new brain MRI T2 lesion development. We included 199 cases in the intention-to-treat analysis based on assigned dose. Of these, 116 converted to multiple sclerosis by 48 weeks (58%). Compared to placebo, the hazard ratios (95% confidence interval) for conversion were 1000 IU 0.87 (0.50, 1.50); 5000 IU 1.37 (0.82, 2.29); and 10 000 IU 1.28 (0.76, 2.14). In an adjusted model including age, sex, latitude, study centre and baseline symptom number, clinically isolated syndrome onset site, presence of infratentorial lesions and use of steroids, the hazard ratios (versus placebo) were 1000 IU 0.80 (0.45, 1.44); 5000 IU 1.36 (0.78, 2.38); and 10 000 IU 1.07 (0.62, 1.85). Vitamin D3 supplementation was safe and well tolerated. We did not demonstrate reduction in multiple sclerosis disease activity by vitamin D3 supplementation after a high-risk clinically isolated syndrome.

Changes in employment status over time in multiple sclerosis following a first episode of central nervous system demyelination, a Markov multistate model study.

BACKGROUND AND PURPOSE: Understanding predictors of changes in employment status among people living with multiple sclerosis (MS) can assist health care providers to develop appropriate work retention/rehabilitation programs. We aimed to model longitudinal transitions of employment status in MS and estimate the probabilities of retaining employment status or losing or gaining employment over time in individuals with a first clinical diagnosis of central nervous system demyelination (FCD). METHODS: This prospective cohort study comprised adults (aged 18-59 years) diagnosed with FCD (n = 237) who were followed for more than 11 years. At each review, participants were assigned to one of three states: unemployed, part-time, or full-time employed. A Markov multistate model was used to examine the rate of state-to-state transitions. RESULTS: At the time of FCD, participants with full-time employment had an 89% chance of being in the same state over a 1-year period, but this decreased to 42% over the 10-year follow-up period. For unemployed participants, there was a 92% likelihood of remaining unemployed after 1 year, but this probability decreased to 53% over 10 years. Females, those who progressed to clinically definite MS, those with a higher relapse count, and those with a greater level of disability were at increased risk of transitioning to a deteriorated employment state. In addition, those who experienced clinically significant fatigue over the follow-up period were less likely to gain employment after being unemployed. CONCLUSIONS: In our FCD cohort, we found a considerable rate of employment transition during the early years post-diagnosis. Over more than a decade of follow-up post-FCD, we found that females and individuals with a greater disability and a higher relapse count are at higher risk of losing employment.

The disease-modifying therapy utilisation and cost trend for multiple sclerosis in Australia between 2013 and 2022.

BACKGROUND: The MS disease-modifying therapies (DMTs) prescribing landscape in Australia have changed over time. OBJECTIVES: This study evaluated the utilisation and cost trends of MS-related DMTs in Australia over 10 years and investigated differences between States/Territories. METHODS: The prescription and costs of 16 DMTs were extracted from the Pharmaceutical Benefits Scheme for 2013-2022. Descriptive approaches analysed the total number of people prescribed DMTs and total DMT costs per 10,000 population, proportions of prescriptions/costs by DMT groups and the number of people prescribed each individual DMT and costs of each DMT over the 10-year period. All estimates were for Australia and each State/Territory individually. RESULTS: The number of people prescribed DMT and costs per 10,000 population had substantial growth between 2013 and 2022: 125%/164% for Australia, and 94%-251%/129%-373% for individual States/Territories. Higher efficacy group accounted for 54% of total people prescribed DMTs in 2013 and 75% in 2022. Fingolimod was the most popular DMT until 2020, then was dominated by ocrelizumab. The trends of individual DMT prescriptions and costs differed between states particularly in Western Australia (WA), Tasmania and Northern Territory (NT). CONCLUSION: DMT prescriptions and costs continuously increased over the last decade, particularly for higher efficacy DMTs, and their trends differed between States/Territories.

HLA-DRB1*15:01 and the MERTK Gene Interact to Selectively Influence the Profile of MERTK-Expressing Monocytes in Both Health and MS.

BACKGROUND AND OBJECTIVES: HLA-DRB1*15:01 (DR15) and MERTK are 2 risk genes for multiple sclerosis (MS). The variant rs7422195 is an expression quantitative trait locus for MERTK in CD14+ monocytes; cells with phagocytic and immunomodulatory potential. We aimed to understand how drivers of disease risk and pathogenesis vary with HLA and MERTK genotype and disease activity. METHODS: We investigated how proportions of monocytes vary with HLA and MERTK genotype and disease activity in MS. CD14+ monocytes were isolated from patients with MS at relapse (n = 40) and 3 months later (n = 23). Healthy controls (HCs) underwent 2 blood collections 3 months apart. Immunophenotypic profiling of monocytes was performed by flow cytometry. Methylation of 35 CpG sites within and near the MERTK gene was assessed in whole blood samples of individuals experiencing their first episode of clinical CNS demyelination (n = 204) and matched HCs (n = 345) using an Illumina EPIC array. RESULTS: DR15-positive patients had lower proportions of CD14+ MERTK+ monocytes than DR15-negative patients, independent of genotype at the MERTK SNP rs7422195. Proportions of CD14+ MERTK+ monocytes were further reduced during relapse in DR15-positive but not DR15-negative patients. Patients homozygous for the major G allele at rs7422195 exhibited higher proportions of CD14+ MERTK+ monocytes at both relapse and remission compared with controls. We observed that increased methylation of the MERTK gene was significantly associated with the presence of DR15. DISCUSSION: DR15 and MERTK genotype independently influence proportions of CD14+ MERTK+ monocytes in MS. We confirmed previous observations that the MERTK risk SNP rs7422195 is associated with altered MERTK expression in monocytes. We identified that expression of MERTK is stratified by disease in people homozygous for the major G allele of rs7422195. The finding that the proportion of CD14+ MERTK+ monocytes is reduced in DR15-positive individuals supports prior data identifying genetic links between these 2 loci in influencing MS risk. DR15 genotype-dependent alterations in methylation of the MERTK gene provides a molecular link between these loci and identifies a potential mechanism by which MERTK expression is influenced by DR15. This links DR15 haplotype to MS susceptibility beyond direct influence on antigen presentation and suggests the need for HLA-based stratification of approaches to MERTK as a therapeutic target.

Using qualitative free-text data to investigate the lived experience of the COVID-19 pandemic for a large cohort of Australians with different multiple sclerosis related disability levels.

BACKGROUND: No large-scale qualitative studies have investigated the lived experience of people living with multiple sclerosis (PwMS) during the pandemic according to their disability level. We used qualitative research methods to investigate the lived experience of a large cohort of Australians living with differing multiple sclerosis (MS)-related disability levels during the COVID-19 pandemic. We also provided useful contextualisation to existing quantitative work. METHODS: This was a retrospective survey-based mixed-methods cohort study. A quality-of-life study was conducted within the Australian MS Longitudinal Study during the pandemic. Disability severity was calculated using the Patient Determined Disease Steps. Qualitative free-text data regarding COVID-19 impacts was collected/analysed for word frequency and also thematically (inductively/deductively using sophisticated grounded theory) using NVivo software. We also triangulated word frequency with emerging themes. RESULTS: N=509 PwMS participated providing n=22 530 words of COVID-19-specific data. Disability severity could be calculated for n=501 PwMS. The word 'working' was important for PwMS with no disability, and 'support' and 'isolation' for higher disability levels. For PwMS with milder disability, thematic analysis established that multitasking increased stress levels, particularly if working from home (WFH) and home-schooling children. If not multitasking, WFH was beneficial for managing fatigue. PwMS with severe disability raised increased social isolation as a concern including prepandemic isolation. CONCLUSIONS: We found negative impacts of multitasking and social isolation for PwMS during the pandemic. WFH was identified as beneficial for some. We recommend targeted resourcing decisions for PwMS in future pandemics including child-care relief and interventions to reduce social isolation and suggest that these could be incorporated into some form of advanced care planning. As the nature of work changes postpandemic, we also recommend a detailed investigation of WFH for PwMS including providing tailored employment assistance.

DNA Methylation Signatures of Multiple Sclerosis Occur Independently of Known Genetic Risk and Are Primarily Attributed to B Cells and Monocytes.

Epigenetic mechanisms can regulate how DNA is expressed independently of sequence and are known to be associated with various diseases. Among those epigenetic mechanisms, DNA methylation (DNAm) is influenced by genotype and the environment, making it an important molecular interface for studying disease etiology and progression. In this study, we examined the whole blood DNA methylation profiles of a large group of people with (pw) multiple sclerosis (MS) compared to those of controls. We reveal that methylation differences in pwMS occur independently of known genetic risk loci and show that they more strongly differentiate disease (AUC = 0.85, 95% CI 0.82-0.89, p = 1.22 × 10-29) than known genetic risk loci (AUC = 0.72, 95% CI: 0.66-0.76, p = 9.07 × 10-17). We also show that methylation differences in MS occur predominantly in B cells and monocytes and indicate the involvement of cell-specific biological pathways. Overall, this study comprehensively characterizes the immune cell-specific epigenetic architecture of MS.

Evaluation of Cell-Specific Epigenetic Age Acceleration in People With Multiple Sclerosis.

BACKGROUND AND OBJECTIVES: In multiple sclerosis (MS), accelerated aging of the immune system (immunosenescence) may be associated with disease onset or drive progression. DNA methylation (DNAm) is an epigenetic factor that varies among lymphocyte subtypes, and cell-specific DNAm is associated with MS. DNAm varies across the life span and can be used to accurately estimate biological age acceleration, which has been linked to a range of morbidities. The objective of this study was to test for cell-specific epigenetic age acceleration (EAA) in people with MS. METHODS: This was a case-control study of EAA using existing DNAm data from several independent previously published studies. Data were included if .idat files from Illumina 450K or EPIC arrays were available for both a case with MS and an age-matched and sex-matched control, from the same study. Multifactor statistical modeling was performed to assess the primary outcome of EAA. We explored the relationship of EAA and MS, including interaction terms to identify immune cell-specific effects. Cell-sorted DNA methylation data from 3 independent datasets were used to validate findings. RESULTS: We used whole blood DNA methylation data from 583 cases with MS and 643 non-MS controls to calculate EAA using the GrimAge algorithm. The MS group exhibited an increased EAA compared with controls (approximately 9 mths, 95% CI 3.6-14.4), p = 0.001). Statistical deconvolution showed that EAA is associated with MS in a B cell-dependent manner (ß int = 1.7, 95% CI 0.3-2.8), p = 0.002), irrespective of B-cell proportions. Validation analysis using 3 independent datasets enriched for B cells showed an EAA increase of 5.1 years in cases with MS compared with that in controls (95% CI 2.8-7.4, p = 5.5 × 10-5). By comparison, there was no EAA difference in MS in a T cell-enriched dataset. We found that EAA was attributed to the DNAm surrogates for Beta-2-microglobulin (difference = 47,546, 95% CI 10,067-85,026; p = 7.2 × 10-5), and smoking pack-years (difference = 8.1, 95% CI 1.9-14.2, p = 0.002). DISCUSSION: This study provides compelling evidence that B cells exhibit marked EAA in MS and supports the hypothesis that premature B-cell immune senescence plays a role in MS. Future MS studies should focus on age-related molecular mechanisms in B cells.

The association between disability progression, relapses, and treatment in early relapse onset MS: an observational, multi-centre, longitudinal cohort study.

The indirect contribution of multiple sclerosis (MS) relapses to disability worsening outcomes, and vice-versa, remains unclear. Disease modifying therapies (DMTs) are potential modulators of this association. Understanding how these endo-phenotypes interact may provide insights into disease pathogenesis and treatment practice in relapse-onset MS (ROMS). Utilising a unique, prospectively collected clinical data from a longitudinal cohort of 279 first demyelinating event cases followed for up to 15 years post-onset, we examined indirect associations between relapses and treatment and the risk of disability worsening, and vice-versa. Indirect association parameters were estimated using joint models for longitudinal and survival data. Early relapses within 2.5 years of MS onset predicted early disability worsening outcomes (HR = 3.45, C.I 2.29-3.61) per relapse, but did not contribute to long-term disability worsening thereinafter (HR = 0.21, C.I 0.15-0.28). Conversely, disability worsening outcomes significantly contributed to relapse risk each year (HR = 2.96, C.I 2.91-3.02), and persisted over time (HR = 3.34, C.I 2.90-3.86), regardless of DMT treatments. The duration of DMTs significantly reduced the hazards of relapses (1st-line DMTs: HR = 0.68, C.I 0.58-0.79; 3rd-line DMTs: HR = 0.37, C.I 0.32-0.44) and disability worsening events (1st-line DMTs: HR = 0.74, C.I 0.69-0.79; 3rd-line DMTs: HR = 0.90, C.I 0.85-0.95), respectively. Results from time-dynamic survival probabilities further revealed individuals having higher risk of future relapses and disability worsening outcomes, respectively. The study provided evidence that in ROMS, relapses accrued within 2.5 years of MS onset are strong indicators of disability worsening outcomes, but late relapses accrued 2.5 years post onset are not overt risk factors for further disability worsening. In contrast, disability worsening outcomes are strong positive predictors of current and subsequent relapse risk. Long-term DMT use and older age strongly influence the individual outcomes and their associations.