The immune cell transcriptome is modulated by vitamin D3 supplementation in people with a first demyelinating event participating in a randomized placebo-controlled trial.

Vitamin D deficiency is a risk factor for developing multiple sclerosis. The PrevANZ trial was conducted to determine if vitamin D3 supplementation can prevent recurrent disease activity in people with a first demyelinating event. As a sub-study of this trial, we investigated the effect of supplementation on peripheral immune cell gene expression. Participants were randomized to 1000, 5000 or 10,000 international units daily of vitamin D3 or placebo. Peripheral blood was collected at baseline and 12 weeks and sent for ribonucleic acid sequencing. Datasets from 55 participants were included. Gene expression was modulated by high dose supplementation. Antigen presentation and viral response pathways were upregulated. Oxidative phosphorylation and immune signaling pathways, including tumor necrosis factor-alpha and interleukin-17 signaling, were downregulated. Overall, vitamin D3 supplementation for 12 weeks modulated the peripheral immune cell transcriptome with induction of anti-inflammatory gene expression profiles. Our results support a dose-dependent effect of vitamin D3 supplementation on immune gene expression.

Balancing the risks and benefits of sun exposure: A revised position statement for Australian adults.

OBJECTIVE: To describe the development of a new position statement regarding balancing the risks and benefits of sun exposure for Australian adults. METHODS: We conducted a Sun Exposure Summit in March 2021, with presentations from invited experts and a workshop including representation from academic, clinical, policy, and patient stakeholder organisations. The group considered advice about balancing the risks and benefits of sun exposure for Australian adults and developed a revised consensus position statement. RESULTS: The balance of risks and benefits of sun exposure is not the same for everybody. For people at very high risk of skin cancer, the risks of exposure likely outweigh the benefits; sun protection is essential. Conversely, people with deeply pigmented skin are at low risk of skin cancer but at high risk of vitamin D deficiency; routine sun protection is not recommended. For those at intermediate risk of skin cancer, sun protection remains a priority, but individuals may obtain sufficient sun exposure to maintain adequate vitamin D status. CONCLUSIONS: The new position statement provides sun exposure advice that explicitly recognises the differing needs of Australia's diverse population. IMPLICATIONS FOR PUBLIC HEALTH: Mass communication campaigns should retain the focus on skin cancer prevention. The new position statement will support the delivery of personalised advice.

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.

The lived experience of multiple sclerosis: Patient insights to guide general practitioner care.

BACKGROUND: Multiple sclerosis (MS) is a neurodegenerative disease with symptoms that are varied and unpredictable, and although there are effective medications to treat some forms of MS, there is no cure. For many, an MS diagnosis means decades living with a chronic illness and disability. OBJECTIVE: Providing medical and support care to people with MS can be a long and complex partnership between the patient and the general practitioner (GP). The aim of this article is to provide knowledge of the lived experience of MS and the factors leading to a reduced quality of life. DISCUSSION: Often alongside the considerable threats to physical health and neurological function that MS poses, there are also significant mental health burdens. This article uses lived experience to outline some of the crucial trigger points where support from the GP, and the wider general practice team, can have a significant impact on a positive path forward for the patient.

Charting a global research strategy for progressive MS-An international progressive MS Alliance proposal.

BACKGROUND: Progressive forms of multiple sclerosis (MS) affect more than 1 million individuals globally. Recent approvals of ocrelizumab for primary progressive MS and siponimod for active secondary progressive MS have opened the therapeutic door, though results from early trials of neuroprotective agents have been mixed. The recent introduction of the term 'active' secondary progressive MS into the therapeutic lexicon has introduced potential confusion to disease description and thereby clinical management. OBJECTIVE: This paper reviews recent progress, highlights continued knowledge and proposes, on behalf of the International Progressive MS Alliance, a global research strategy for progressive MS. METHODS: Literature searches of PubMed between 2015 and May, 2021 were conducted using the search terms "progressive multiple sclerosis", "primary progressive multiple sclerosis", "secondary progressive MS". Proposed strategies were developed through a series of in-person and virtual meetings of the International Progressive MS Alliance Scientific Steering Committee. RESULTS: Sustaining and accelerating progress will require greater understanding of underlying mechanisms, identification of potential therapeutic targets, biomarker discovery and validation, and conduct of clinical trials with improved trial design. Encouraging developments in symptomatic and rehabilitative interventions are starting to address ongoing challenges experienced by people with progressive MS. CONCLUSION: We need to manage these challenges and realise the opportunities in the context of a global research strategy, which will improve quality of life for people with progressive MS.

Epstein-Barr virus, latitude and multiple sclerosis.

Several lines of evidence support a role for Epstein-Barr virus (EBV) in the aetiology of multiple sclerosis (MS). This includes the observation that nearly all MS patients show serological markers of past EBV infection. Given the well-known association between MS prevalence and latitude, we investigated whether EBV seropositivity also increases with distance from the equator. We found that the proportion of EBV positive individuals is positively associated with latitude independently of MS status (odds ratio = 1.06, 95% CI = 1.02-1.09, p = 0.002). Latitude-related factors may be implicated in the immune response to EBV and its role in MS aetiology.

Genetic, environmental and stochastic factors in monozygotic twin discordance with a focus on epigenetic differences.

Genetic-epidemiological studies on monozygotic (MZ) twins have been used for decades to tease out the relative contributions of genes and the environment to a trait. Phenotypic discordance in MZ twins has traditionally been ascribed to non-shared environmental factors acting after birth, however recent data indicate that this explanation is far too simple. In this paper, we review other reasons for discordance, including differences in the in utero environment, genetic mosaicism, and stochastic factors, focusing particularly on epigenetic discordance. Epigenetic differences are gaining increasing recognition. Although it is clear that in specific cases epigenetic alterations provide a causal factor in disease etiology, the overall significance of epigenetics in twin discordance remains unclear. It is also challenging to determine the causality and relative contributions of environmental, genetic, and stochastic factors to epigenetic variability. Epigenomic profiling studies have recently shed more light on the dynamics of temporal methylation change and methylome heritability, yet have not given a definite answer regarding their relevance to disease, because of limitations in establishing causality. Here, we explore the subject of epigenetics as another component in human phenotypic variability and its links to disease focusing particularly on evidence from MZ twin studies.

Month of birth, vitamin D and risk of immune-mediated disease: a case control study.

BACKGROUND: A season of birth effect in immune-mediated diseases (ID) such as multiple sclerosis and type 1 diabetes has been consistently reported. We aimed to investigate whether season of birth influences the risk of rheumatoid arthritis, Crohn's disease, ulcerative colitis and systemic lupus erythematosus in addition to multiple sclerosis, and to explore the correlation between the risk of ID and predicted ultraviolet B (UVB) light exposure and vitamin D status during gestation. METHODS: The monthly distribution of births of patients with ID from the UK (n = 115,172) was compared to that of the general population using the Cosinor test. Predicted UVB radiation and vitamin D status in different time windows during pregnancy were calculated for each month of birth and correlated with risk of ID using the Spearman's correlation coefficient. RESULTS: The distributions of ID births significantly differed from that of the general population (P = 5e-12) with a peak in April (odds ratio = 1.045, 95% confidence interval = 1.024, 1.067, P < 0.0001) and a trough in October (odds ratio = 0.945, 95% confidence interval = 0.925, 0.966, P < 0.0001). Stratification by disease subtype showed seasonality in all ID but Crohn's disease. The risk of ID was inversely correlated with predicted second trimester UVB exposure (Spearman's rho = -0.49, P = 0.00005) and third trimester vitamin D status (Spearman's rho = -0.44, P = 0.0003). CONCLUSIONS: The risk of different ID in the UK is significantly influenced by the season of birth, suggesting the presence of a shared seasonal risk factor or factors predisposing to ID. Gestational UVB and vitamin D exposure may be implicated in the aetiology of ID.

Exome sequencing identifies a novel multiple sclerosis susceptibility variant in the TYK2 gene.

OBJECTIVE: To identify rare variants contributing to multiple sclerosis (MS) susceptibility in a family we have previously reported with up to 15 individuals affected across 4 generations. METHODS: We performed exome sequencing in a subset of affected individuals to identify novel variants contributing to MS risk within this unique family. The candidate variant was genotyped in a validation cohort of 2,104 MS trio families. RESULTS: Four family members with MS were sequenced and 21,583 variants were found to be shared among these individuals. Refining the variants to those with 1) a predicted loss of function and 2) present within regions of modest haplotype sharing identified 1 novel mutation (rs55762744) in the tyrosine kinase 2 (TYK2) gene. A different polymorphism within this gene has been shown to be protective in genome-wide association studies. In contrast, the TYK2 variant identified here is a novel, missense mutation and was found to be present in 10/14 (72%) cases and 28/60 (47%) of the unaffected family members. Genotyping additional 2,104 trio families showed the variant to be transmitted preferentially from heterozygous parents (transmitted 16: not transmitted 5; χ(2) = 5.76, p = 0.016). CONCLUSIONS: Rs55762744 is a rare variant of modest effect on MS risk affecting a subset of patients (0.8%). Within this pedigree, rs55762744 is common and appears to be a modifier of modest risk effect. Exome sequencing is a quick and cost-effective method and we show here the utility of sequencing a few cases from a single, unique family to identify a novel variant. The sequencing of additional family members or other families may help identify other variants important in MS.

Vitamin D receptor binding, chromatin states and association with multiple sclerosis.

Both genetic and environmental factors contribute to the aetiology of multiple sclerosis (MS). More than 50 genomic regions have been associated with MS susceptibility and vitamin D status also influences the risk of this complex disease. However, how these factors interact in disease causation is unclear. We aimed to investigate the relationship between vitamin D receptor (VDR) binding in lymphoblastoid cell lines (LCLs), chromatin states in LCLs and MS-associated genomic regions. Using the Genomic Hyperbrowser, we found that VDR-binding regions overlapped with active regulatory regions [active promoter (AP) and strong enhancer (SE)] in LCLs more than expected by chance [45.3-fold enrichment for SE (P < 2.0e-05) and 63.41-fold enrichment for AP (P < 2.0e-05)]. Approximately 77% of VDR regions were covered by either AP or SE elements. The overlap between VDR binding and regulatory elements was significantly greater in LCLs than in non-immune cells (P < 2.0e-05). VDR binding also occurred within MS regions more than expected by chance (3.7-fold enrichment, P < 2.0e-05). Furthermore, regions of joint overlap SE-VDR and AP-VDR were even more enriched within MS regions and near to several disease-associated genes. These findings provide relevant insights into how vitamin D influences the immune system and the risk of MS through VDR interactions with the chromatin state inside MS regions. Furthermore, the data provide additional evidence for an important role played by B cells in MS. Further analyses in other immune cell types and functional studies are warranted to fully elucidate the role of vitamin D in the immune system.

Multiple sclerosis: risk factors and their interactions.

Multiple sclerosis (MS) is a highly debilitating immune mediated disorder of the central nervous system and represents a substantial burden to the developed world. Despite the recent advances in MS research, which risk factors are implicated and how they contribute to MS pathogenesis is largely unknown. However, in line with older studies investigating the genetic and geographical epidemiology of this complex disease, more recent studies have highlighted how MS arises from a combination of genetic susceptibility and environmental exposures acting from gestation to early adulthood. Vitamin D deficiency, season of birth, Epstein Barr virus infection, and smoking behaviour are strongly implicated and able to influence genetic predisposition to MS. Furthermore, these factors appear to act synergistically and the risk of MS in individuals exposed to more than one factor combines multiplicatively. Current evidence suggests that a large part of MS could be prevented and understanding how and when during life risk factors act will ultimately aid the development of prevention strategies.

Seasonal distribution of psychiatric births in England.

There is general consensus that season of birth influences the risk of developing psychiatric conditions later in life. We aimed to investigate whether the risk of schizophrenia (SC), bipolar affective disorder (BAD) and recurrent depressive disorder (RDD) is influenced by month of birth in England to a similar extent as other countries using the largest cohort of English patients collected to date (n = 57,971). When cases were compared to the general English population (n = 29,183,034) all diseases showed a seasonal distribution of births (SC p = 2.48E-05; BAD p = 0.019; RDD p = 0.015). This data has implications for future strategies of disease prevention.

Genomic regions associated with multiple sclerosis are active in B cells.

More than 50 genomic regions have now been shown to influence the risk of multiple sclerosis (MS). However, the mechanisms of action, and the cell types in which these associated variants act at the molecular level remain largely unknown. This is especially true for associated regions containing no known genes. Given the evidence for a role for B cells in MS, we hypothesized that MS associated genomic regions co-localized with regions which are functionally active in B cells. We used publicly available data on 1) MS associated regions and single nucleotide polymorphisms (SNPs) and 2) chromatin profiling in B cells as well as three additional cell types thought to be unrelated to MS (hepatocytes, fibroblasts and keratinocytes). Genomic intervals and SNPs were tested for overlap using the Genomic Hyperbrowser. We found that MS associated regions are significantly enriched in strong enhancer, active promoter and strong transcribed regions (p = 0.00005) and that this overlap is significantly higher in B cells than control cells. In addition, MS associated SNPs also land in active promoter (p = 0.00005) and enhancer regions more than expected by chance (strong enhancer p = 0.0006; weak enhancer p = 0.00005). These results confirm the important role of the immune system and specifically B cells in MS and suggest that MS risk variants exert a gene regulatory role. Previous studies assessing MS risk variants in T cells may be missing important effects in B cells. Similar analyses in other immunological cell types relevant to MS and functional studies are necessary to fully elucidate how genes contribute to MS pathogenesis.

Functional analysis of missense variants in the TRESK (KCNK18) K channel.

A loss of function mutation in the TRESK K2P potassium channel (KCNK18), has recently been linked with typical familial migraine with aura. We now report the functional characterisation of additional TRESK channel missense variants identified in unrelated patients. Several variants either had no apparent functional effect, or they caused a reduction in channel activity. However, the C110R variant was found to cause a complete loss of TRESK function, yet is present in both sporadic migraine and control cohorts, and no variation in KCNK18 copy number was found. Thus despite the previously identified association between loss of TRESK channel activity and migraine in a large multigenerational pedigree, this finding indicates that a single non-functional TRESK variant is not alone sufficient to cause typical migraine and highlights the genetic complexity of this disorder.

An approach to finding brain-situated mutations in sporadic Parkinson's disease.

Sporadic Parkinson's disease (PD) is thought to have a major genetic component, but the variants involved remain mostly unknown. One possible reason for the difficulty in finding mutations underlying PD is that rare predominantly brain-situated somatic mutations underlie the disease; these mutations would be missed by analysing blood DNA only. To test the feasibility of looking for somatic mutations in PD brain tissue, we compared copy number variants (CNVs) between 8 PD and 26 control brains using Affymetrix 6.0 arrays. The median number of CNVs per brain, and the overall proportion of amplifications and deletions, were similar in PD and control brains. In 7 of the 8 PD brains, however, a total of 45 CNVs were found that were not present in control brains. Twelve of these CNVs overlapped with one or more genes, some of which are involved in pathways suspected in the pathogenesis of PD, or are rare. This study shows that PD brain CNVs can be detected, and raises the possibility that brain-situated mutations could underlie some cases of PD. A method of undertaking a definitive study of brain somatic mutations in PD, using massively parallel sequencing and multiple tissues, is suggested.

Rare variants in the CYP27B1 gene are associated with multiple sclerosis.

OBJECTIVE: Multiple sclerosis (MS) is a complex neurological disease. Genetic linkage analysis and genotyping of candidate genes in families with 4 or more affected individuals more heavily loaded for susceptibility genes has not fully explained familial disease clustering. METHODS: We performed whole exome sequencing to further understand the heightened prevalence of MS in these families. RESULTS: Forty-three individuals with MS (1 from each family) were sequenced to find rare variants in candidate MS susceptibility genes. On average, >58,000 variants were identified in each individual. A rare variant in the CYP27B1 gene causing complete loss of gene function was identified in 1 individual. Homozygosity for this mutation results in vitamin D-dependent rickets I (VDDR1), whereas heterozygosity results in lower calcitriol levels. This variant showed significant heterozygous association in 3,046 parent-affected child trios (p = 1 × 10(-5)). Further genotyping in >12,500 individuals showed that other rare loss of function CYP27B1 variants also conferred significant risk of MS, Peto odds ratio = 4.7 (95% confidence interval, 2.3-9.4; p = 5 × 10(-7)). Four known VDDR1 mutations were identified, all overtransmitted. Heterozygous parents transmitted these alleles to MS offspring 35 of 35× (p = 3 × 10(-9)). INTERPRETATION: A causative role for CYP27B1 in MS is supported; the mutations identified are known to alter function having been shown in vivo to result in rickets when 2 copies are present. CYP27B1 encodes the vitamin D-activating 1-alpha hydroxylase enzyme, and thus a role for vitamin D in MS pathogenesis is strongly implicated.

Looking for differences in copy number between blood and brain in sporadic amyotrophic lateral sclerosis.

INTRODUCTION: Most analyses of blood DNA in sporadic neuromuscular disorders have been inconclusive. This may be because some genetic variants occur only in brain tissue. We therefore looked for copy number variants (CNVs) in both blood and brain in patients with sporadic amyotrophic lateral sclerosis (SALS). METHODS: Genome-wide CNVs were compared in blood and brain from 32 SALS patients and from 26 normal (control) brains, using Affymetrix 6.0 arrays. RESULTS: There were 410 CNVs present in brain but not blood (somatic CNVs) in 94% of the patients (median 8 CNVs per patient). Twenty-four of the somatic CNVs were rare, were not found in control brains, and overlapped with genes. CONCLUSIONS: Brain-specific CNVs may be common and appear to be present in a proportion of patients with SALS. The more detailed copy number analysis that is becoming available with massively parallel sequencing may uncover brain-specific CNVs that underlie some cases of SALS.

Copy number imbalances in blood and hair in monozygotic twins discordant for amyotrophic lateral sclerosis.

Chromosomal copy number association studies in patients with amyotrophic lateral sclerosis (ALS) using blood DNA have so far been inconclusive. We employed genome-wide screening to look for copy number imbalances (CNIs) between blood and hair DNA from three ALS-discordant monozygotic twin pairs and two phenotypically normal monozygotic twin pairs. Genome-wide chromosomal copy number was estimated using AffyMetrix 6.0 GeneChips. CNIs were sought both between twin pairs and between blood and hair DNA from the same individuals. Two blood CNIs were found in one ALS-discordant twin pair. In another ALS-discordant twin pair, seven hair CNIs were detected. CNIs were also found between blood and hair in three individuals. Imbalances in blood copy number appear to be rare in monozygotic twin pairs, but hair may harbour more CNIs than blood. Copy number differences between blood and hair from the same individuals appear to be common. Since brain and hair share a common ectodermal origin, hair may be a more suitable tissue than blood to estimate somatic copy number variation in the brain.

Using case-parent trios to look for rare de novo genetic variants in adult-onset neurodegenerative diseases.

Rare de novo genetic variants have been detected in a number of diseases using case-parent trios. So far, trio studies have largely been confined to early-onset diseases where parent DNA samples are readily available. To test the feasibility of finding rare de novo variants in a typical late-onset neurodegenerative disease, we compared genome-wide copy number variants (CNVs) between patients with sporadic amyotrophic lateral sclerosis (SALS) and their unaffected parents. DNA from 12 SALS patients and their 24 parents was analysed for CNVs using AffyMetrix SNP 6.0 microarrays and Partek software. De novo CNVs (present in patients but not their parents) considered likely candidates for SALS were those that overlapped with CNS-related genes, were rare, or were found in multiple patients. All SALS patients had de novo CNVs. In 11 patients, 37 de novo CNVs fulfilled one or more criteria for a candidate region. Eleven de novo CNVs overlapped with genes, some of which are in pathways suspected in the pathogenesis of SALS. In conclusion, this pilot study shows that trios can be used to look for rare de novo genetic variants in patients with late adult-onset neurodegenerative disease. The results suggest that further studies of this nature with larger numbers of trios are warranted, but it is unusual to find surviving parents of offspring who have a late-onset neurodegenerative disease. An international collaborative effort will therefore be needed to collect sufficient numbers of such trios to reliably detect de novo mutations underlying these diseases.

Epigenetic mechanisms in multiple sclerosis and the major histocompatibility complex (MHC).

Multiple sclerosis (MS) is a complex disorder of the central nervous system characterized by demyelination, axonal loss, and inflammation. The cause of MS is currently unknown although genetic and environmental factors contribute to etiology. The relative importance of each has been disputed; however, now it is clear that much of the disease results from the interaction of the environment and the genetics. Epigenetic modifications within the major histocompatibility complex (MHC) likely mediate interactions at this locus with current known environmental risk factors--vitamin D, Epstein-Barr virus, and smoking. Maternal parent-of-origin effects, month of birth effects and transgenerational differences in allele frequency are also evident in MS and may be mediated by sex-specific epigenetic mechanisms. Differences in epigenetic marks characterize monozygotic twin pairs and may explain discordance. There is promise of potential therapeutic strategies to be found in the epigenetic mechanisms at work in MS.