Conjoint Professor Jeannette Lechner-Scott

© 2017, Springer-Verlag Italia S.r.l. Despite extensive studies focusing on the changes in expression of microRNAs (miRNAs) in multiple sclerosis (MS) compared to healthy controls, few studies have evaluated the association of genetic variants of miRNAs with MS clinical course. We investigated whether a functional polymorphism in the MS associated miR-146a gene predicted clinical course (hazard of conversion to MS and of relapse, and annualized change in disability), using a longitudinal cohort study of persons with a first demyelinating event followed up to their 5-year review. We found the genotype (GC+CC) of rs2910164 predicted relapse compared with the GG genotype (HR=2.09 (95% CI 1.42, 3.06), p=0.0001), as well as a near-significant (p=0.07) association with MS conversion risk. Moreover, we found a significant additive interaction between rs2910164 and baseline anti-EBNA-1 IgG titers predicting risk of conversion to MS (relative excess risk due to interaction [RERI] 2.39, p=0.00002) and of relapse (RERI 1.20, p=0.006). Supporting these results, similar results were seen for the other EBV-correlated variables: anti-EBNA-2 IgG titers and past history of infectious mononucleosis. There was no association of rs2910164 genotype for disability progression. Our findings provide evidence for miR-146a and EBV infection in modulating MS clinical course.

© 2017 Multiple Sclerosis (MS) is a chronic neurological disease with genetic and environmental risk factors. Epstein Barr-Virus (EBV) has been closely associated with MS but with a significant amount of conflicting evidence. Some of the evidence for EBV involvement in MS includes: almost 100% of MS patients showing past EBV infection, an association with Infectious Mononucleosis (acute EBV infection), higher titres of EBV antibodies associated with an increased risk of MS development, and an overall altered immune response to EBV found in peripheral blood and the CNS of MS patients. However, evidence for EBV presence in the CSF and T cell responses to EBV in MS have been particularly conflicting. Several hypotheses have been proposed for direct and indirect EBV involvement in MS such as 1) Molecular Mimicry 2) Mistaken Self 3) Bystander Damage and 4) Autoreactive B cells infected with EBV. More recently, an association between EBV and human endogenous retrovirus in MS has been shown, which may provide an alternative pathogenetic target for MS treatment. However, if EBV is not the major contributor to MS and is instead one of several viral or infectious agents able to elicit a similar altered immune response, MS development may be the result of a failure of viral clearance in general. This review aims to evaluate the evidence for the currently discussed theories of EBV involvement in MS pathogenesis.

© 2017 Article author(s). Objectives: We have undertaken a clinic-based survey of neuromyelitis optica spectrum disorders (NMOSDs) in Australia and New Zealand to establish incidence and prevalence across the region and in populations of differing ancestry. Background: NMOSD is a recently defined demyelinating disease of the central nervous system (CNS). The incidence and prevalence of NMOSD in Australia and New Zealand has not been established. Methods: Centres managing patients with demyelinating disease of the CNS across Australia and New Zealand reported patients with clinical and laboratory features that were suspicious for NMOSD. Testing for aquaporin 4 antibodies was undertaken in all suspected cases. From this group, cases were identified who fulfilled the 2015 Wingerchuk diagnostic criteria for NMOSD. A capture-recapture methodology was used to estimate incidence and prevalence, based on additional laboratory identified cases. Results: NMOSD was confirmed in 81/170 (48%) cases referred. Capture-recapture analysis gave an adjusted incidence estimate of 0.37 (95% CI 0.35 to 0.39) per million per year and a prevalence estimate for NMOSD of 0.70 (95% CI 0.61 to 0.78) per 100 000. NMOSD was three times more common in the Asian population (1.57 (95% CI 1.15 to 1.98) per 100 000) compared with the remainder of the population (0.57 (95% CI 0.50 to 0.65) per 100 000). The latitudinal gradient evident in multiple sclerosis was not seen in NMOSD. Conclusions: NMOSD incidence and prevalence in Australia and New Zealand are comparable with figures from other populations of largely European ancestry. We found NMOSD to be more common in the population with Asian ancestry.

© 2017, American Psychiatric Association. All rights reserved. Neurological and psychological symptoms in multiple sclerosis can affect cognitive function. The objective of this study was to explore the relationship between psychological measures and cognitive performance in a patient cohort. In 322 multiple sclerosis patients, psychological symptoms were measured using the Depression Anxiety and Stress Scale, and cognitive function was evaluated using Audio Recorded Cognitive Screen. Multifactor linear regression analysis, accounting for all clinical covariates, found that anxiety was the only psychological measure to remain a significant predictor of cognitive performance (p<0.001), particularly memory function (p<0.001). Further prospective studies are required to determine whether treatment of anxiety improves cognitive impairment.

© BMJ Publishing Group Limited 2016. Objective: To evaluate variability and predictability of disability trajectories in moderately advanced and advanced multiple sclerosis (MS), and their modifiability with immunomodulatory therapy. Methods The epochs between Expanded Disability Status Scale (EDSS) steps 3.6, 4.6 and 6.6.5 were analysed. Patients with relapse-onset MS and having reached 6-month confirmed baseline EDSS step (3/4/6) were identified in MSBase, a global observational MS cohort study. We used multivariable survival models to examine the impact of disease-modifying therapy, clinical and demographic factors on progression to the outcome EDSS step (6/6.5). Sensitivity analyses with varying outcome definitions and inclusion criteria were conducted. Results: For the EDSS 3.6, 4.6 and 6.6.5 epochs, 1560, 1504 and 1231 patients were identified, respectively. Disability trajectories showed large coefficients of variance prebaseline (0.92.1.11) and postbaseline (2.15.2.50), with no significant correlations. The probability of reaching the outcome step was not associated with prebaseline variables, but was increased by higher relapse rates during each epoch (HRs 1.58.3.07; p<0.001). A greater proportion of each epoch treated with higher efficacy therapies was associated with lower risk of reaching the outcome disability step (HRs 0.72.0.91 per 25%; p=0.02). 3 sensitivity analyses confirmed these results. Conclusions: Disease progression during moderately advanced and advanced MS is highly variable and amnesic to prior disease activity. Lower relapse rates and greater time on higher efficacy immunomodulatory therapy after reaching EDSS steps 3, 4 and 6 are associated with a decreased risk of accumulating further disability. Highly effective immunomodulatory therapy ameliorates accumulation of disability in moderately advanced and advanced relapse-onset MS.

© The Author(s), 2016. Background: Since 1959, multiple sclerosis (MS) prevalence has been estimated for the east coast Australian city of Newcastle. Previous surveys, conducted in 1988 and 2003, have described an increase in the prevalence and incidence of MS. Objectives: In this study, we evaluated whether these trends continue and provide 50 years of MS epidemiological follow-up for this southern hemisphere city. Methods: Expressed per 100,000 people, prevalence of MS in Newcastle was calculated for those with a confirmed diagnosis of MS on 9 August 2011 and incidence based on the number of cases with MS diagnosis made during the preceding decade. Data were age-standardised to the total Australian population. Statistical comparisons were undertaken using Poisson regression analysis. Results: In 2011, the estimate of MS prevalence was 124.2, with female-to-male ratio reaching 3.1, a 53% increase in female predominance since 1996. MS incidence increased to 6.7, with a significantly higher proportion of new female cases since the previous survey. Conclusion: Prevalence of MS in Newcastle has risen linearly and is contributed to by a substantial increase in new cases over the preceding decade. Female predominance of MS cases continues to increase with a new diagnosis three times more likely in women.

© 2016, © The Author(s), 2016. Background: The importance of the innate immune system in multiple sclerosis (MS) is increasingly recognized and the role of natural killer (NK) cells in controlling autoimmunity may be an important modulator of disease activity. Objective: To examine NK subsets in MS patients on different treatments and to evaluate the role of NK subsets as indicators for disease activity. Methods: We measured NK subset levels in blood obtained from 110 relapsing-remitting MS patients. Patients were either off treatment or on treatment with natalizumab, fingolimod, glatiramer acetate or beta-interferon. Disease activity was defined according to ¿No Evidence of Disease Activity¿ (NEDA) criteria within an observation period of up to 2.4 years. The mean NK subset levels were compared among treatment groups using multivariate analysis of variance (ANOVA) and association analysis with disease activity performed using multi-factor logistic regression. Results: Our analysis revealed differences in NK cells and subsets on treatment compared to off treatment (p < 0.0005). A high proportion of bright NK cells were significantly associated with stable magnetic resonance imaging (MRI) imaging after adjusting for treatment effects (p < 0.05). Conclusion: The independent association of NK subsets with MRI stability needs to be confirmed in prospective studies to test their usefulness in predicting disease activity in MS patients.

© 2017 Elsevier Ltd Background Alemtuzumab, an anti-CD52 antibody, is proven to be more efficacious than interferon beta-1a in the treatment of relapsing-remitting multiple sclerosis, but its efficacy relative to more potent immunotherapies is unknown. We compared the effectiveness of alemtuzumab with natalizumab, fingolimod, and interferon beta in patients with relapsing-remitting multiple sclerosis treated for up to 5 years. Methods In this international cohort study, we used data from propensity-matched patients with relapsing-remitting multiple sclerosis from the MSBase and six other cohorts. Longitudinal clinical data were obtained from 71 MSBase centres in 21 countries and from six non-MSBase centres in the UK and Germany between Nov 1, 2015, and June 30, 2016. Key inclusion criteria were a diagnosis of definite relapsing-remitting multiple sclerosis, exposure to one of the study therapies (alemtuzumab, interferon beta, fingolimod, or natalizumab), age 65 years or younger, Expanded Disability Status Scale (EDSS) score 6·5 or lower, and no more than 10 years since the first multiple sclerosis symptom. The primary endpoint was annualised relapse rate. The secondary endpoints were cumulative hazards of relapses, disability accumulation, and disability improvement events. We compared relapse rates with negative binomial models, and estimated cumulative hazards with conditional proportional hazards models. Findings Patients were treated between Aug 1, 1994, and June 30, 2016. The cohorts consisted of 189 patients given alemtuzumab, 2155 patients given interferon beta, 828 patients given fingolimod, and 1160 patients given natalizumab. Alemtuzumab was associated with a lower annualised relapse rate than interferon beta (0·19 [95% CI 0·14¿0·23] vs 0·53 [0·46¿0·61], p<0·0001) and fingolimod (0·15 [0·10¿0·20] vs 0·34 [0·26¿0·41], p<0·0001), and was associated with a similar annualised relapse rate as natalizumab (0·20 [0·14¿0·26] vs 0·19 [0·15¿0·23], p=0·78). For the disability outcomes, alemtuzumab was associated with similar probabilities of disability accumulation as interferon beta (hazard ratio [HR] 0·66 [95% CI 0·36¿1·22], p=0·37), fingolimod (1·27 [0·60¿2·70], p=0·67), and natalizumab (0·81 [0·47¿1·39], p=0·60). Alemtuzumab was associated with similar probabilities of disability improvement as interferon beta (0·98 [0·65¿1·49], p=0·93) and fingolimod (0·50 [0·25¿1·01], p=0·18), and a lower probability of disability improvement than natalizumab (0·35 [0·20¿0·59], p=0·0006). Interpretation Alemtuzumab and natalizumab seem to have similar effects on annualised relapse rates in relapsing-remitting multiple sclerosis. Alemtuzumab seems superior to fingolimod and interferon beta in mitigating relapse activity. Natalizumab seems superior to alemtuzumab in enabling recovery from disability. Both natalizumab and alemtuzumab seem highly effective and viable immunotherapies for multiple sclerosis. Treatment decisions between alemtuzumab and natalizumab should be primarily governed by their safety profiles. Funding National Health and Medical Research Council, and the University of Melbourne.

© 2017 American Academy of Neurology. To investigate the effect of disease-modifying treatment on short-term disability outcomes in secondary progressive multiple sclerosis (SPMS). Methods: Using MSBase, an international cohort study, we previously validated a highly accurate definition of SPMS. Here, we identified patients in MSBase who were either untreated or treated with a disease-modifying drug when meeting this definition. Propensity score matching was used to select subpopulations with comparable baseline characteristics. Disability outcomes were compared in paired, pairwise-censored analyses adjusted for treatment persistence, visit density, and relapse rates. Results: Of the 2,381 included patients, 1,378 patients were matchable (treated n = 689, untreated n = 689). Median pairwise-censored follow-up was 2.1 years (quartiles 1.2-3.8 years). No difference in the risk of 6-month sustained disability progression was observed between the groups (hazard ratio [HR] 0.9, 95% confidence interval [CI] 0.7-1.1, p = 0.27). We also did not find differences in any of the secondary endpoints: Risk of reaching Expanded Disability Status Scale (EDSS) score =7 (HR 0.6, 95% CI 0.4-1.1, p = 0.10), sustained disability reduction (HR 1.0, 95% CI 0.8-1.3, p = 0.79), or change in disability burden (area under the EDSS-time curve, ß =-0.05, p = 0.09). Secondary and sensitivity analyses confirmed the results. Conclusions: Our pooled analysis of the currently available disease-modifying agents used after conversion to SPMS suggests that, on average, these therapies have no substantial effect on relapse-unrelated disability outcomes measured by the EDSS up to 4 years. Classification of evidence: This study provides Class IV evidence that for patients with SPMS, disease-modifying treatment has no beneficial effect on short-term disability progression.

© 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. Up to 50% of multiple sclerosis (MS) patients do not respond to interferon-beta (IFN-ß) treatment and determination of response requires lengthy clinical follow-up of up to 2 years. Response predictive genetic markers would significantly improve disease management. We aimed to identify IFN-ß treatment response genetic marker(s) by performing a two-stage genome-wide association study (GWAS). The GWAS was carried out using data from 151 Australian MS patients from the ANZgene/WTCCC2 MS susceptibility GWAS (responder (R)=51, intermediate responders=24 and non-responders (NR)=76). Of the single-nucleotide polymorphisms (SNP) that were validated in an independent group of 479 IFN-ß-treated MS patients from Australia, Spain and Italy (R=273 and NR=206), eight showed evidence of association with treatment response. Among the replicated associations, the strongest was observed for FHIT (Fragile Histidine Triad; combined P-value 6.74 × 106) and followed by variants in GAPVD1 (GTPase activating protein and VPS9 domains 1; combined P-value 5.83 × 10 5) and near ZNF697 (combined P-value 8.15 × 10 5).

© 2016 The Royal Australian and New Zealand College of Radiologists Introduction: Patients presenting with clinically isolated syndrome (CIS) may proceed to clinically definite multiple sclerosis (CDMS). Midsagittal corpus callosum area (CCA) is a surrogate marker for callosal atrophy, and can be obtained from a standard MRI study. This study explores the relationship between CCA measured at CIS presentation (baseline) and at 5¿years post presentation, with conversion from CIS to CDMS. The association between CCA and markers of disability progression is explored. Methods: Corpus callosum area was measured on MRI scans at presentation and 5-year review following diagnosis of a first demyelinating event, or evidence of progressive MS, in 143 participants in the Ausimmune/AusLong Study. Relationships between CCA (at baseline and follow-up) and clinical outcomes were assessed. Results: Mean CCA at baseline study was 6.63¿cm2(SD 1.01). Patients who converted to MS by 5-year review (n¿=¿100) had a significantly smaller mean CCA at follow-up (6.22 vs. 6.74, P¿=¿0.007). Greater CCA reduction was associated with higher annualized relapse rate over follow-up. Conclusion: Baseline CCA obtained from standard MRI protocols may be compared with subsequent MRI examinations as a surrogate for neurodegeneration and cerebral atrophy in patients with MS. This study demonstrates an association between CCA and disability in individuals presenting with CIS who convert to MS.

© 2016 Binder et al. Multiple Sclerosis (MS) is a chronic inflammatory demyelinating disease of the central nervous system. The risk of developing MS is strongly influenced by genetic predisposition, and over 100 loci have been established as associated with susceptibility. However, the biologically relevant variants underlying disease risk have not been defined for the vast majority of these loci, limiting the power of these genetic studies to define new avenues of research for the development of MS therapeutics. It is therefore crucial that candidate MS susceptibility loci are carefully investigated to identify the biological mechanism linking genetic polymorphism at a given gene to the increased chance of developing MS. MERTK has been established as an MS susceptibility gene and is part of a family of receptor tyrosine kinases known to be involved in the pathogenesis of demyelinating disease. In this study we have refined the association of MERTK with MS risk to independent signals from both common and low frequency variants. One of the associated variants was also found to be linked with increased expression of MERTK in monocytes and higher expression of MERTK was associated with either increased or decreased risk of developing MS, dependent upon HLA-DRB1*15:01 status. This discordant association potentially extended beyond MS susceptibility to alterations in disease course in established MS. This study provides clear evidence that distinct polymorphisms within MERTK are associated with MS susceptibility, one of which has the potential to alter MERTK transcription, which in turn can alter both susceptibility and disease course in MS patients.

© SAGE Publications. Objective: We aimed to analyse the effect of the introduction of fingolimod, the first oral disease-modifying therapy, on treatment utilisation and persistence in an international cohort of patients with multiple sclerosis (MS). Methods: MSBASIS, a prospective, observational sub-study of the MSBase registry, collects demographic, clinical and paraclinical data on patients followed from MS onset (n=4718). We conducted a multivariable conditional risk set survival analysis to identify predictors of treatment discontinuation, and to assess if the introduction of fingolimod has altered treatment persistence. Results: A total of 2640 patients commenced immunomodulatory therapy. Following the introduction of fingolimod, patients were more likely to discontinue all other treatments (hazard ratio 1.64, p<0.001) while more patients switched to fingolimod than any other therapy (42.3% of switches). Patients switched to fingolimod due to convenience. Patients treated with fingolimod were less likely to discontinue treatment compared with other therapies (p<0.001). Female sex, country of residence, younger age, a high Expanded Disability Status Scale score and relapse activity were all independently associated with higher rates of treatment discontinuation. Conclusion: Following the availability of fingolimod, patients were more likely to discontinue injectable treatments. Those who switched to fingolimod were more likely to do so for convenience. Persistence was improved on fingolimod compared to other medications.

Background Discontinuation of injectable diseasemodifying therapy (DMT) for multiple sclerosis (MS) after a long period of relapse freedom is frequently considered, but data on post-cessation disease course are lacking. Objectives (1) To compare time to first relapse and disability progression among 'DMT stoppers' and propensity-score matched 'DMT stayers' in the MSBase Registry; (2) To identify predictors of time to first relapse and disability progression in DMT stoppers. Methods Inclusion criteria for DMT stoppers were: age =18 years; no relapses for =5 years at DMT discontinuation; follow-up for =3 years after stopping DMT; not restarting DMT for =3 months after discontinuation. DMT stayers were required to have no relapses for =5 years at baseline, and were propensityscore matched to stoppers for age, sex, disability (Expanded Disability Status Score), disease duration and time on treatment. Relapse and disability progression events in matched stoppers and stayers were compared using a marginal Cox model. Predictors of first relapse and disability progression among DMT stoppers were investigated using a Cox proportional hazards model. Results Time to first relapse among 485 DMT stoppers and 854 stayers was similar (adjusted HR, aHR=1.07, 95% CI 0.84 to 1.37; p=0.584), while time to confirmed disability progression was significantly shorter among DMT stoppers than stayers (aHR=1.47, 95% CI 1.18 to 1.84, p=0.001). The difference in hazards of progression was due mainly to patients who had not experienced disability progression in the prebaseline treatment period. Conclusions Patients with MS who discontinued injectable DMT after a long period of relapse freedom had a similar relapse rate as propensity score-matched patients who continued on DMT, but higher hazard for disability progression.

© 2016 Published by the BMJ Publishing Group Limited. Background The genetic drivers of multiple sclerosis (MS) clinical course are essentially unknown with limited data arising from severity and clinical phenotype analyses in genome-wide association studies. Methods Prospective cohort study of 127 first demyelinating events with genotype data, where 116 MS risk-Associated single nucleotide polymorphisms (SNPs) were assessed as predictors of conversion to MS, relapse and annualised disability progression (Expanded Disability Status Scale, EDSS) up to 5-year review (I "EDSS). Survival analysis was used to test for predictors of MS and relapse, and linear regression for disability progression. The top 7 SNPs predicting MS/relapse and disability progression were evaluated as a cumulative genetic risk score (CGRS). Results We identified 2 non-human leucocyte antigen (HLA; rs12599600 and rs1021156) and 1 HLA (rs9266773) SNP predicting both MS and relapse risk. Additionally, 3 non-HLA SNPs predicted only conversion to MS; 1 HLA and 2 non-HLA SNPs predicted only relapse; and 7 non-HLA SNPs predicted I "EDSS. The CGRS significantly predicted MS and relapse in a significant, dose-dependent manner: Those having =5 risk genotypes had a 6-fold greater risk of converting to MS and relapse compared with those with =2. The CGRS for I "EDSS was also significant: Those carrying =6 risk genotypes progressed at 0.48 EDSS points per year faster compared with those with =2, and the CGRS model explained 32% of the variance in disability in this study cohort. Conclusions These data strongly suggest that MS genetic risk variants significantly influence MS clinical course and that this effect is polygenic.

© 2016 American Academy of Neurology. Background: We compared efficacy and treatment persistence in treatment-naive patients with relapsing-remitting multiple sclerosis (RRMS) initiating natalizumab compared with interferon-ß (IFN-ß)/glatiramer acetate (GA) therapies, using propensity score-matched cohorts from observational multiple sclerosis registries. Methods: The study population initiated IFN-ß/GA in the MSBase Registry or natalizumab in the Tysabri Observational Program, had =3 months of on-treatment follow-up, and had active RRMS, defined as =1 gadolinium-enhancing lesion on cerebral MRI at baseline or =1 relapse within the 12 months prior to baseline. Baseline demographics and disease characteristics were balanced between propensity-matched groups. Annualized relapse rate (ARR), time to first relapse, treatment persistence, and disability outcomes were compared between matched treatment arms in the total population (n 366/group) and subgroups with higher baseline disease activity. Results: First-line natalizumab was associated with a 68% relative reduction in ARR from a mean (SD) of 0.63 (0.92) on IFN-ß/GA to 0.20 (0.63) (p [signed-rank] < 0.0001), a 64% reduction in the rate of first relapse (hazard ratio [HR] 0.36, 95% confidence interval [CI] 0.28-0.47; p < 0.001), and a 27% reduction in the rate of discontinuation (HR 0.73, 95% CI 0.58-0.93; p 0.01), compared with first-line IFN-ß/GA therapy. Confirmed disability progression and area under the Expanded Disability Status Scale-time curve analyses were not significant. Similar relapse and treatment persistence results were observed in each of the higher disease activity subgroups. Conclusions: This study provides Class IV evidence that first-line natalizumab for RRMS improves relapse and treatment persistence outcomes compared to first-line IFN-ß/GA. This needs to be balanced against the risk of progressive multifocal leukoencephalopathy in natalizumab-treated patients. Classification of evidence: This study provides Class IV evidence that first-line natalizumab for RRMS improves relapse rates and treatment persistence outcomes compared to first-line IFN-ß/GA.

© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd Background: Anxiety and depression are common in multiple sclerosis (MS). We evaluated the prevalence and factors associated with anxiety, depression and fatigue at the 5-year review of a longitudinal cohort study following a first clinical diagnosis of CNS demyelination (FCD). Methods: Cases with a FCD were recruited soon after diagnosis and followed annually thereafter. A variety of environmental, behavioural and clinical covariates were measured at five-year review. Anxiety and depression were measured using the Hospital Anxiety & Depression Scale (HADS), and fatigue by the Fatigue Severity Scale (FSS). Results: Of the 236 cases, 40.2% had clinical anxiety (median HADS-A: 6.0), 16.0% had clinical depression (median HADS-D: 3.0), and 41.3% had clinical fatigue (median FSS: 4.56). The co-occurrence of all three symptoms was 3.76 times greater than expectation. Younger age, higher disability, concussion or other disease diagnosis were independently associated with a higher anxiety score; male sex, higher disability, being unemployed, less physical activity, and antidepressant and/or anxiolytic-sedative medication use were independently associated with a higher depression score. Higher disability, immunomodulatory medication use, other disease diagnosis and anxiolytic-sedative medication use were independently associated with having fatigue, while female sex, higher BMI, having had a concussion, being unemployed and higher disability were associated with a higher fatigue score. Conclusion: These results support previous findings of the commonality of anxiety, depression and fatigue in established MS and extend this to post-FCD and early MS cases. The clustering of the three symptoms indicates that they may share common antecedents.

© 2016 Published by the BMJ Publishing Group Limited. Background: Age at onset (AAO) in multiple sclerosis (MS) is an important marker of disease severity and may have prognostic significance. Understanding what factors can influence AAO may shed light on the aetiology of this complex disease, and have applications in the diagnostic process. Methods: The study cohort of 22 162 eligible patients from 21 countries was extracted from the MSBase registry. Only patients with MS aged =16 years were included. To reduce heterogeneity, only centres of largely European descent were included for analysis. AAO was defined as the year of the first symptom suggestive of inflammatory central nervous system demyelination. Predictors of AAO were evaluated by linear regression. Results: Compared with those living in lower latitudes (19.0-39.9°), onset of symptoms was 1.9 years earlier for those at higher latitudes (50.0-56.0°) (p=3.83×10-23). A reciprocal relationship was seen for ambient ultraviolet radiation (UVR), with a significantly increasing AAO for patients with MS per each quartile increment of ambient UVR (p=1.56×10-17). We found that the AAO of female patients was ~5 months earlier than male patients (p=0.002). AAO of progressive-onset patients with MS were ~9 years later than relapsing-onset patients (p=1.40×10-265). Conclusions: An earlier AAO in higher latitude regions was found in this worldwide European-descent cohort and correlated inversely with variation in latitudinal UVR. These results suggest that environmental factors which act at the population level may significantly influence disease severity characteristics in genetically susceptible populations.

© 2016. Background and Purpose: Early relapse outcomes in long-term stable patients switching from interferon ß/glatiramer acetate (IFNß/GA) to oral therapy are unknown. Objective: The objective of this study was to compare early relapse and progression in multiple sclerosis (MS) patients switching to oral therapy following a period of stable disease on IFNß/GA, relative to a propensity-matched comparator of patients remaining on IFNß/GA. Methods: The MSBase cohort study is a global, longitudinal registry for MS. Time to first 6-month relapse in previously stable MS patients switching from platform injectables ('switchers') to oral agents were compared with propensity-matched patients remaining on IFNß/GA ('stayers') using a Cox marginal model. Results: Three-hundred and ninety-six switchers were successfully matched to 396 stayers on a 1:1 basis. There was no difference in the proportion of patients recording at least one relapse in the first 1-6 months by treatment arm (7.3% switchers, 6.6% stayers; P = 0.675). The mean annualized relapse rate (P = 0.493) and the rate of first 6-month relapse by treatment arm (hazard ratio 1.22, 95% confidence interval 0.70, 2.11) were also comparable. There was no difference in the rate of disability progression by treatment arm (hazard ratio 1.43, 95% confidence interval 0.63, 3.26). Conclusion: This is the first study to compare early relapse switch probability in the period immediately following switch to oral treatment in a population previously stable on injectable therapy. There was no evidence of disease reactivation within the first 6 months of switching to oral therapy.

© SAGE Publications. Background: Multiple sclerosis (MS) is a debilitating disease that negatively impacts patients' lives. Objective: ENABLE assessed the effect of long-term prolonged-release (PR) fampridine (dalfampridine extended release in the United States) treatment on patient-perceived health impact in patients with MS with walking impairment. Methods: ENABLE was a 48-week, open-label, Phase 4 study of PR-fampridine 10 mg twice daily. Patients who showed any improvement in Timed 25-Foot Walk walking speed at weeks 2 and 4 and any improvement in 12-item MS Walking Scale score at week 4 remained on treatment. The primary endpoint was change from baseline in 36-Item Short-Form Health Survey (SF-36) physical component summary (PCS) score. Results: At week 4, 707/901 (78.5%) patients met the criteria to remain on treatment. Patients on treatment demonstrated significant and clinically meaningful improvements in SF-36 PCS scores from baseline (mean change (95% confidence interval)) to week 12 (4.30 (3.83, 4.78); p < 0.0001), week 24 (3.75 (3.23, 4.27); p < 0.0001), week 36 (3.46 (2.95, 3.97); p < 0.0001), and week 48 (3.24 (2.72, 3.77); p < 0.0001). Significant improvements from baseline were also demonstrated in secondary health measures in patients on treatment. Conclusion: PR-fampridine improved patient-perceived physical and psychological health impact of MS measured in a real-life setting.

© 2015 AMPCo Pty Ltd. Produced with Elsevier B.V. All rights reserved. Multiple sclerosis (MS) is an autoimmune disease of the central nervous system with a multifactorial aetiology and highly variable natural history. A growing understanding of the immunopathogenesis of the condition has led to an expanding array of therapies for this previously untreatable disease. While a cure for MS remains elusive, the potential to reduce inflammatory disease activity by preventing relapses and minimising disease progression is achievable. The importance of early treatment in minimising long-term disability is increasingly recognised. Most of the newer, more effective therapies are associated with risks and practical problems that necessitate an active management strategy and continuous vigilance. While the initiation of these therapies is likely to remain the responsibility of neurologists, other specialist physicians and general practitioners will be involved in the identification and management of adverse effects.

Background and purpose: Early prediction of long-term disease evolution is a major challenge in the management of multiple sclerosis (MS). Our aim was to predict the natural course of MS using the Bayesian Risk Estimate for MS at Onset (BREMSO), which gives an individual risk score calculated from demographic and clinical variables collected at disease onset. Methods: An observational study was carried out collecting data from MS patients included in MSBase, an international registry. Disease impact was studied using the Multiple Sclerosis Severity Score (MSSS) and time to secondary progression (SP). To evaluate the natural history of the disease, patients were analysed only if they did not receive immune therapies or only up to the time of starting these therapies. Results: Data from 14 211 patients were analysed. The median BREMSO score was significantly higher in the subgroups of patients whose disease had a major clinical impact (MSSS= third quartile vs. = first quartile, P < 0.00001) and who reached SP (P < 0.00001). The BREMSO showed good specificity (79%) as a tool for predicting the clinical impact of MS. Conclusions: BREMSO is a simple tool which can be used in the early stages of MS to predict its evolution, supporting therapeutic decisions in an observational setting.

© 2015 Ribbons et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Background: Multiple Sclerosis is more common in women than men and females have more relapses than men. In a large international cohort we have evaluated the effect of gender on disability accumulation and disease progression to determine if male MS patients have a worse clinical outcome than females. Methods: Using the MSBase Registry, data from 15,826 MS patients from 25 countries was analysed. Changes in the severity of MS (EDSS) were compared between sexes using a repeated measures analysis in generalised linear mixed models. Kaplan-Meier analysis was used to test for sex difference in the time to reach EDSS milestones 3 and 6 and the secondary progressive MS. Results: In relapse onset MS patients (n = 14,453), males progressed significantly faster in their EDSS than females (0.133 vs 0.112 per year, P<0.001,). Females had a reduced risk of secondary progressive MS (HR (95% CI) = 0.77 (0.67 to 0.90) P = 0.001). In primary progressive MS (n = 1,373), there was a significant increase in EDSS over time in males and females (P<0.001) but there was no significant sex effect on the annualized rate of EDSS change. Conclusion: Among registrants of MSBase, male relapse-onset patients accumulate disability faster than female patients. In contrast, the rate of disability accumulation between male and female patients with primary progressive MS is similar.

© 2015 The Author. Immunological hallmarks of multiple sclerosis include the production of antibodies in the central nervous system, expressed as presence of oligoclonal bands and/or an increased immunoglobulin G index-the level of immunoglobulin G in the cerebrospinal fluid compared to serum. However, the underlying differences between oligoclonal band-positive and-negative patients with multiple sclerosis and reasons for variability in immunoglobulin G index are not known. To identify genetic factors influencing the variation in the antibody levels in the cerebrospinal fluid in multiple sclerosis, we have performed a genome-wide association screen in patients collected from nine countries for two traits, presence or absence of oligoclonal bands (n = 3026) and immunoglobulin G index levels (n = 938), followed by a replication in 3891 additional patients. We replicate previously suggested association signals for oligoclonal band status in the major histocompatibility complex region for the rs9271640*A-rs6457617*G haplotype, correlated with HLA-DRB1*1501, and rs34083746*G, correlated with HLA-DQA1*0301 (P comparing two haplotypes = 8.88 × 10^-16). Furthermore, we identify a novel association signal of rs9807334, near the ELAC1/SMAD4 genes, for oligoclonal band status (P = 8.45 × 10^-7). The previously reported association of the immunoglobulin heavy chain locus with immunoglobulin G index reaches strong evidence for association in this data set (P = 3.79 × 10^-37). We identify two novel associations in the major histocompatibility complex region with immunoglobulin G index: the rs9271640*A-rs6457617*G haplotype (P = 1.59 × 10^-22), shared with oligoclonal band status, and an additional independent effect of rs6457617*G (P = 3.68 × 10^-6). Variants identified in this study account for up to 2-fold differences in the odds of being oligoclonal band positive and 7.75% of the variation in immunoglobulin G index. Both traits are associated with clinical features of disease such as female gender, age at onset and severity. This is the largest study population so far investigated for the genetic influence on antibody levels in the cerebrospinal fluid in multiple sclerosis, including 6950 patients. We confirm that genetic factors underlie these antibody levels and identify both the major histocompatibility complex and immunoglobulin heavy chain region as major determinants.

� 2015 American Neurological Association. Objective: In patients suffering multiple sclerosis activity despite treatment with interferon ß or glatiramer acetate, clinicians often switch therapy to either natalizumab or fingolimod. However, no studies have directly compared the outcomes of switching to either of these agents. Methods: Using MSBase, a large international, observational, prospectively acquired cohort study, we identified patients with relapsing-remitting multiple sclerosis experiencing relapses or disability progression within the 6 months immediately preceding switch to either natalizumab or fingolimod. Quasi-randomization with propensity score-based matching was used to select subpopulations with comparable baseline characteristics. Relapse and disability outcomes were compared in paired, pairwise-censored analyses. Results: Of the 792 included patients, 578 patients were matched (natalizumab, n = 407; fingolimod, n = 171). Mean on-study follow-up was 12 months. The annualized relapse rates decreased from 1.5 to 0.2 on natalizumab and from 1.3 to 0.4 on fingolimod, with 50% relative postswitch difference in relapse hazard (p = 0.002). A 2.8 times higher rate of sustained disability regression was observed after the switch to natalizumab in comparison to fingolimod (p<0.001). No difference in the rate of sustained disability progression events was observed between the groups. The change in overall disability burden (quantified as area under the disability-time curve) differed between natalizumab and fingolimod (20.12 vs 0.04 per year, respectively, p<0.001). Interpretation: This study suggests that in active multiple sclerosis during treatment with injectable disease-modifying therapies, switching to natalizumab is more effective than switching to fingolimod in reducing relapse rate and short-term disability burden.

© 2015 The Author. Evidence exists for a potential modulation of inflammasome activity by interferon beta. Here, we investigated the roles of inflammasomes [absent in melanoma 2 (AIM2); NLR family, CARD domain containing 4 (NLRC4); NLR family, pyrin domain containing 1 and 3 (NLRP1 and NLRP3)] and related cytokines (IL1B, IL10, IL18) in the response to interferon beta in patients with relapsing-remitting multiple sclerosis. Ninety-seven patients treated with interferon beta were classified into responders and non-responders according to clinical criteria after 24 months and clinical-radiological criteria after 12 months of treatment. Messenger RNA expression levels of inflammasomes and cytokines were determined by real-time polymerase chain reaction in peripheral blood mononuclear cells collected before treatment with interferon beta. In a subgroup of patients, NLRP3 and IL1B expression was also determined after 3 months (n = 32) and 12 months (n = 20) of interferon beta treatment. A polymorphism located in the NLRP3 gene, rs35829419, was genotyped in 789 multiple sclerosis patients treated with interferon beta. Baseline mRNA expression levels for NLRP3 and IL1B were increased in peripheral blood mononuclear cells from non-responders compared to responders classified according to clinical criteria after 24 months (P = 0.02 and P = 0.001, respectively). No significant differences were observed for other inflammasomes and related cytokines. Differences in NLRP3 and IL1B expression remained significant following a clinical-radiological classification after 12 months (P = 0.007 and P = 0.02, respectively). After treatment with interferon beta, NLRP3 and IL1B expression was increased in responders but unchanged in non-responders. A trend for association was observed between rs35829419 and interferon beta response (pM-H = 0.08). These results point to a role of the NLRP3 inflammasome and its related cytokine IL1B in the response to interferon beta in patients with relapsing-remitting multiple sclerosis.

© 2015 Field et al. Human genetic and animal studies have implicated the costimulatory molecule CD40 in the development of multiple sclerosis (MS). We investigated the cell specific gene and protein expression variation controlled by the CD40 genetic variant(s) associated with MS, i.e. the T-allele at rs1883832. Previously we had shown that the risk allele is expressed at a lower level in whole blood, especially in people with MS. Here, we have defined the immune cell subsets responsible for genotype and disease effects on CD40 expression at the mRNA and protein level. In cell subsets in which CD40 is most highly expressed, B lymphocytes and dendritic cells, the MS-associated risk variant is associated with reduced CD40 cell-surface protein expression. In monocytes and dendritic cells, the risk allele additionally reduces the ratio of expression of full-length versus truncated CD40 mRNA, the latter encoding secreted CD40. We additionally show that MS patients, regardless of genotype, express significantly lower levels of CD40 cell-surface protein compared to unaffected controls in B lymphocytes. Thus, both genotype-dependent and independent down-regulation of cell-surface CD40 is a feature of MS. Lower expression of a co-stimulator of T cell activation, CD40, is therefore associated with increased MS risk despite the same CD40 variant being associated with reduced risk of other inflammatory autoimmune diseases. Our results highlight the complexity and likely individuality of autoimmune pathogenesis, and could be consistent with antiviral and/or immunoregulatory functions of CD40 playing an important role in protection from MS.

© 2015 The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain. All rights reserved. For Permissions, please email: journals.permissions@oup.com. Prevention of irreversible disability is currently the most important goal of disease modifying therapy for multiple sclerosis. The disability outcomes used in most clinical trials rely on progression of Expanded Disability Status Scale score confirmed over 3 or 6 months. However, sensitivity and stability of this metric has not been extensively evaluated. Using the global MSBase cohort study, we evaluated 48 criteria of disability progression, testing three definitions of baseline disability, two definitions of progression magnitude, two definitions of long-term irreversibility and four definitions of event confirmation period. The study outcomes comprised the rates of detected progression events per 10 years and the proportions of the recorded events persistent at later time points. To evaluate the ratio of progression frequency and stability for each criterion, we calculated the proportion of events persistent over the five subsequent years once progression was achieved. Finally, we evaluated the clinical and demographic determinants characterising progression events and, for those that regressed back to baseline, determinants of their subsequent regression. The study population consisted of 16 636 patients with the minimum of three recorded disability scores, totalling 112 584 patient-years. The progression rates varied between 0.41 and 1.14 events per 10 years, with the length of required confirmation interval as the most important determinant of the observed variance. The concordance among all tested progression criteria was only 17.3%. Regression of disability occurred in 11-34% of the progression events over the five subsequent years. The most important determinant of progression stability was the length of the confirmation period. For the most accurate set of the progression criteria, the proportions of 3-, 6-, 12- or 24-month confirmed events persistent over 5 years reached 70%, 74%, 80% and 89%, respectively. Regression post progression was more common in younger patients, relapsing-remitting disease course, and after a smaller change in disability, and was inflated by higher visit frequency. These results suggest that the disability outcomes based on 3-6-month confirmed disability progression overestimate the accumulation of permanent disability by up to 30%. This could lead to spurious results in short-term clinical trials, and the issue may be magnified further in cohorts consisting predominantly of younger patients and patients with relapsing-remitting disease. Extension of the required confirmation period increases the persistence of progression events.

Background: Multiple sclerosis (MS) is thought to be caused by T-cell mediated autoimmune dysfunction. Risk ofdeveloping MS is influenced by environmental and genetic factors. Modifiable differences in DNA methylation arerecognized as epigenetic contributors to MS risk and may provide a valuable link between environmental exposure andinherited genetic systems.Objectives and methods: To identify methylation changes associated with MS, we performed a genome-wide DNAmethylation analysis of CD4+ T cells from 30 patients with relapsing-remitting MS and 28 healthy controls using Illumina450K methylation arrays.Results: A striking differential methylation signal was observed at chr. 6p21, with a peak signal at HLA-DRB1. Afterprioritisation, we identified a panel of 74 CpGs associated with MS in this cohort. Most notably we found evidence of amajor effect CpG island in DRB1 in MS cases (pFDR <3 x 10^-3). In addition, we found 55 non-HLA CpGs that exhibiteddifferential methylation, many of which localise to genes previously linked to MS.Conclusions: Our findings provide the first evidence for association of DNA methylation at HLA-DRB1 in relation toMS risk. Further studies are now warranted to validate and understand how these findings are involved in MS pathology. © The Author(s) 2013.

In Part 2 of this three part review of multiple sclerosis (MS) treatment with a particular focus on the Australian and New Zealand perspective, we review the newer therapies that have recently become available and emerging therapies that have now completed phase III clinical trial programs. We go on to compare the relative efficacies of these newer and emerging therapies alongside the existing therapies. The effectiveness of ß-interferon in the treatment of different stages and the different disease courses of MS is critically reviewed with the conclusion that the absolute level of response in term of annualised relapse rates (where relapses occur) and MRI activity are similar, but are disappointing in terms of sustained disability progression for progressive forms of the disease. Finally we review the controversial area of combination therapy for MS. Whilst it remains the case that we have no cure or means of preventing MS, we do have a range of effective therapies that when used appropriately and early in the disease course can have a significant impact on short term and longer term outcomes. Crown Copyright © 2014.

In this third and final part of our review of multiple sclerosis (MS) treatment we look at the practical day-to-day management issues that are likely to influence individual treatment decisions. Whilst efficacy is clearly of considerable importance, tolerability and the potential for adverse effects often play a significant role in informing individual patient decisions. Here we review the issues surrounding switching between therapies, and the evidence to assist guiding the choice of therapy to change to and when to change. We review the current level of evidence with regards to the management of women in their child-bearing years with regards to recommendations about treatment during pregnancy and whilst breast feeding. We provide a summary of recommended pre- and post-treatment monitoring for the available therapies and review the evidence with regards to the value of testing for antibodies which are known to be neutralising for some therapies. We review the occurrence of adverse events, both the more common and troublesome effects and those that are less common but have potentially much more serious outcomes. Ways of mitigating these risks and managing the more troublesome adverse effects are also reviewed. Finally, we make specific recommendations with regards to the treatment of MS. It is an exciting time in the world of MS neurology and the prospects for further advances in coming years are high. Crown Copyright © 2014.

Multiple sclerosis (MS) is a potentially life-changing immune mediated disease of the central nervous system. Until recently, treatment has been largely confined to acute treatment of relapses, symptomatic therapies and rehabilitation. Through persistent efforts of dedicated physicians and scientists around the globe for 160 years, a number of therapies that have an impact on the long term outcome of the disease have emerged over the past 20 years. In this three part series we review the practicalities, benefits and potential hazards of each of the currently available and emerging treatment options for MS. We pay particular attention to ways of abrogating the risks of these therapies and provide advice on the most appropriate indications for using individual therapies. In Part 1 we review the history of the development of MS therapies and its connection with the underlying immunobiology of the disease. The established therapies for MS are reviewed in detail and their current availability and indications in Australia and New Zealand are summarised. We examine the evidence to support their use in the treatment of MS. Crown Copyright © 2014.

© VC 2014 American Neurological Association. Objective: Previous studies assessing seasonal variation of relapse onset in multiple sclerosis have had conflicting results. Small relapse numbers, differing diagnostic criteria, and single region studies limit the generalizability of prior results. The aim of this study was to determine whether there is a temporal variation in onset of relapses in both hemispheres and to determine whether seasonal peak relapse probability varies with latitude.Methods: The international MSBase Registry was utilized to analyze seasonal relapse onset distribution by hemisphere and latitudinal location. All analyses were weighted for the patient number contributed by each center. A sine regression model was used to model relapse onset and ultraviolet radiation (UVR) seasonality. Linear regression was used to investigate associations of latitude and lag between UVR trough and subsequent relapse peak. Results: A total of 32,762 relapses from 9,811 patients across 30 countries were analyzed. Relapse onset followed an annual cyclical sinusoidal pattern with peaks in early spring and troughs in autumn in both hemispheres. Every 10- of latitude away from the equator was associated with a mean decrease in UVR trough to subsequent relapse peak lag of 28.5 days (95% confidence interval 5 3.29-53.71, p50.028).Interpretation: We demonstrate for the first time that there is a latitude-dependent relationship between seasonal UVR trough and relapse onset probability peak independent of location-specific UVR levels, with more distal latitude associated with shorter gaps. We confirm prior meta-analyses showing a strong seasonal relapse onset probability variation in the northern hemisphere, and extend this observation to the southern hemisphere.

© The Author(s) 2014. Objectives: The aim was to analyse risk of relapse phenotype recurrence in multiple sclerosis and to characterise the effect of demographic and clinical features on this phenotype. Methods: Information about relapses was collected using MSBase, an international observational registry. Associations between relapse phenotypes and history of similar relapses or patient characteristics were tested with multivariable logistic regression models. Tendency of relapse phenotypes to recur sequentially was assessed with principal component analysis. Results: Among 14,969 eligible patients (89,949 patient-years), 49,279 phenotypically characterised relapses were recorded. Visual and brainstem relapses occurred more frequently in early disease and in younger patients. Sensory relapses were more frequent in early or non-progressive disease. Pyramidal, sphincter and cerebellar relapses were more common in older patients and in progressive disease. Women presented more often with sensory or visual symptoms. Men were more prone to pyramidal, brainstem and cerebellar relapses. Importantly, relapse phenotype was predicted by the phenotypes of previous relapses. (OR = 1.8-5, p = 10-14). Sensory, visual and brainstem relapses showed better recovery than other relapse phenotypes. Relapse severity increased and the ability to recover decreased with age or more advanced disease. Conclusion: Relapse phenotype was associated with demographic and clinical characteristics, with phenotypic recurrence significantly more common than expected by chance.

Matrix metalloproteinase 9 (MMP9) is involved in multiple sclerosis (MS) aetiology. Previously, we identified differential gene expression of plasminogen activation cascade genes in MS patients. Based on our gene expression results, we wanted to identify whether polymorphisms in the genes associated with the plasminogen pathway could predict MS risk. We genotyped 1153 trio families, 727 MS cases and 604 healthy controls for 17 polymorphisms in MMP9, plasminogen activator urokinase (PLAU), PLAU receptor (PLAUR) and serpin peptidase inhibitor/clade 2/member B2 (SERPINB2) genes. No associations were found between the 17 polymorphisms and MS. Also, gene expression levels were analysed according to genotype: no associations were observed. In conclusion despite the consistent evidence for the role of MMP9 and the plasminogen activation cascade in MS, we found no associations between genotype nor gene expression. This suggested there are other potentially modifiable factors influencing gene expression in MS. © The Author(s) 2013.

Background: Multiple Sclerosis (MS) is an immune-mediated disease of the central nervous system which responds to therapies targeting circulating immune cells. Objective: Our aim was to test if the T-cell activation gene expression pattern (TCAGE) we had previously described from whole blood was replicated in an independent cohort. Methods: We used RNA-seq to interrogate the whole blood transcriptomes of 72 individuals (40 healthy controls, 32 untreated MS). A cohort of 862 control individuals from the Brisbane Systems Genetics Study (BSGS) was used to assess heritability and seasonal expression. The effect of interferon beta (IFNB) therapy on expression was evaluated. Results: The MS/TCAGE association was replicated and rationalized to a single marker, ribosomal protein S6 (RPS6). Expression of RPS6 was higher in MS than controls (p<0.0004), and lower in winter than summer (p<4.6E-06). The seasonal pattern correlated with monthly UV light index (R=0.82, p<0.002), and was also identified in the BSGS cohort (p<0.0016). Variation in expression of RPS6 was not strongly heritable. RPS6 expression was reduced by IFNB therapy. Conclusions: These data support investigation of RPS6 as a potential therapeutic target and candidate biomarker for measuring clinical response to IFNB and other MS therapies, and of MS disease heterogeneity.© The Author(s) 2013.

Background: Several studies have shown that pregnancy reduces multiple sclerosis (MS) relapses, which increase in the early postpartum period. Postpartum relapse risk has been predicted by pre-pregnancy disease activity in some studies. Objective: To re-examine effect of pregnancy on relapses using the large international MSBase Registry, examining predictors of early postpartum relapse. Methods: An observational case-control study was performed including pregnancies post-MS onset. Annualised relapse rate (ARR) and median Expanded Disability Status Scale (EDSS) scores were compared for the 24 months pre-conception, pregnancy and 24 months postpartum periods. Clustered logistic regression was used to investigate predictors of early postpartum relapses. Results: The study included 893 pregnancies in 674 females with MS. ARR (standard error) pre-pregnancy was 0.32 (0.02), which fell to 0.13 (0.03) in the third trimester and rose to 0.61 (0.06) in the first three months postpartum. Median EDSS remained unchanged. Pre-conception ARR and disease-modifying treatment (DMT) predicted early postpartum relapse in a multivariable model. Conclusion: Results confirm a favourable effect on relapses as pregnancy proceeds, and an early postpartum peak. Preconception DMT exposure and low ARR were independently protective against postpartum relapse. This novel finding could provide clinicians with a strategy to minimise postpartum relapse risk in women with MS planning pregnancy.© The Author(s) 2013.

The aim of this work was to evaluate sex differences in the incidence of multiple sclerosis relapses; assess the relationship between sex and primary progressive disease course; and compare effects of age and disease duration on relapse incidence. Annualized relapse rates were calculated using the MSBase registry. Patients with incomplete data or <1 year of follow-up were excluded. Patients with primary progressive multiple sclerosis were only included in the sex ratio analysis. Relapse incidences over 40 years of multiple sclerosis or 70 years of age were compared between females and males with Andersen-Gill and Tweedie models. Female-to-male ratios stratified by annual relapse count were evaluated across disease duration and patient age and compared between relapse-onset and primary progressive multiple sclerosis. The study cohort consisted of 11 570 eligible patients with relapse-onset and 881 patients with primary progressive multiple sclerosis. Among the relapse-onset patients (82 552 patient-years), 48 362 relapses were recorded. Relapse frequency was 17.7% higher in females compared with males. Within the initial 5 years, the female-to-male ratio increased from 2.3:1 to 3.3:1 in patients with 0 versus =4 relapses per year, respectively. The magnitude of this sex effect increased at longer disease duration and older age (P < 10-12). However, the female-to-male ratio in patients with relapse-onset multiple sclerosis and zero relapses in any given year was double that of the patients with primary progressive multiple sclerosis. Patient age was a more important determinant of decline in relapse incidence than disease duration (P < 10-12). Females are predisposed to higher relapse activity than males. However, this difference does not explain the markedly lower female-to-male sex ratio in primary progressive multiple sclerosis. Decline in relapse activity over time is more closely related to patient age than disease duration. © The Author (2013).

We conducted an association study across the human leukocyte antigen (HLA) complex to identify loci associated with multiple sclerosis (MS). Comparing 1927 SNPs in 1618 MS cases and 3413 controls of European ancestry, we identified seven SNPs that were independently associated with MS conditional on the others (each P=4×10-6). All associations were significant in an independent replication cohort of 2212 cases and 2251 controls (P=0:001) and were highly significant in the combined dataset (P=6 × 10-8). The associated SNPs included proxies for HLA-DRB1*15:01 and HLA-DRB1*03:01, and SNPs in moderate linkage disequilibrium (LD) with HLA-A*02:01, HLA-DRB1*04:01 and HLA-DRB1*13:03. We also found a strong association with rs9277535 in the class II gene HLA-DPB1 (discovery set P = 9 × 10-9, replication set P = 7 × 10-4, combined P=2 × 10-10). HLA-DPB1 is located centromeric of the more commonly typed class II genes HLA-DRB1, -DQA1 and -DQB1. It is separated from these genes by a recombination hotspot, and the association is not affected by conditioning on genotypes at DRB1, DQA1 and DQB1. Hence rs9277535 represents an independent MS-susceptibility locus of genome-wide significance. It is correlated with the HLA-DPB1*03:01 allele, which has been implicated previously in MS in smaller studies. Further genotyping in large datasets is required to confirm and resolve this association. © 2010 Field et al.