Correlates and trajectories of relapses in relapsing-remitting multiple sclerosis.

BACKGROUND AND AIMS: In people with relapsing-remitting multiple sclerosis (pwRRMS), data from studies on non-pharmacological factors which may influence relapse risk, other than age, are inconsistent. There is a reduced risk of relapses with increasing age, but little is known about other trajectories in real-world MS care. METHODS: We studied longitudinal questionnaire data from 3885 pwRRMS, covering smoking, comorbidities, disease-modifying therapy (DMT), and patient-reported outcome measures, as well as relapses during the past year. We undertook Rasch analysis, group-based trajectory modelling, and multilevel negative binomial regression. RESULTS: The regression cohort of 6285 data sets from pwRRMS over time showed that being a current smoker was associated with 43.9% greater relapse risk; having 3 or more comorbidities increased risk and increasing age reduced risk. Those diagnosed within the last 2 years showed two distinct trajectories, both reducing in relapse frequency but 25.8% started with a higher rate and took 4 years to reduce to the rate of the second group. In the cohort with at least three data points completed, there were three groups: 73.7% followed a low stable relapse rate, 21.6% started from a higher rate and decreased, and 4.7% had an increasing then decreasing pattern. These different trajectory groups showed significant differences in fatigue, neuropathic pain, disability, health status, quality of life, self-efficacy, and DMT use. CONCLUSIONS: These results provide additional evidence for supporting pwRRMS to stop smoking and underline the importance of timely DMT decisions and treatment initiation soon after diagnosis with RRMS.

Guillain-Barré Syndrome Variant Occurring after SARS-CoV-2 Vaccination.

Although SARS-CoV-2 vaccines are very safe, we report 4 cases of the bifacial weakness with paresthesias variant of Guillain-Barré syndrome (GBS) occurring within 3 weeks of vaccination with the Oxford-AstraZeneca SARS-CoV-2 vaccine. This rare neurological syndrome has previously been reported in association with SARS-CoV-2 infection itself. Our cases were given either intravenous immunoglobulin, oral steroids, or no treatment. We suggest vigilance for cases of bifacial weakness with paresthesias variant GBS following vaccination for SARS-CoV-2 and that postvaccination surveillance programs ensure robust data capture of this outcome, to assess for causality. ANN NEUROL 2021;90:315-318.

Experimental infection with the hookworm, Necator americanus, is associated with stable gut microbial diversity in human volunteers with relapsing multiple sclerosis.

BACKGROUND: Helminth-associated changes in gut microbiota composition have been hypothesised to contribute to the immune-suppressive properties of parasitic worms. Multiple sclerosis is an immune-mediated autoimmune disease of the central nervous system whose pathophysiology has been linked to imbalances in gut microbial communities. RESULTS: In the present study, we investigated, for the first time, qualitative and quantitative changes in the faecal bacterial composition of human volunteers with remitting multiple sclerosis (RMS) prior to and following experimental infection with the human hookworm, Necator americanus (N+), and following anthelmintic treatment, and compared the findings with data obtained from a cohort of RMS patients subjected to placebo treatment (PBO). Bacterial 16S rRNA high-throughput sequencing data revealed significantly decreased alpha diversity in the faecal microbiota of PBO compared to N+ subjects over the course of the trial; additionally, we observed significant differences in the abundances of several bacterial taxa with putative immune-modulatory functions between study cohorts. Parabacteroides were significantly expanded in the faecal microbiota of N+ individuals for which no clinical and/or radiological relapses were recorded at the end of the trial. CONCLUSIONS: Overall, our data lend support to the hypothesis of a contributory role of parasite-associated alterations in gut microbial composition to the immune-modulatory properties of hookworm parasites.

Coordinate based meta-analysis of networks in neuroimaging studies.

Meta-analysis of summary results from published neuroimaging studies independently testing a common hypothesis is performed using coordinate based meta-analysis (CBMA), which tests for consistent activation (in the case of functional MRI studies) of the same anatomical regions. Using just the reported coordinates it is also possible to meta-analyse coactivated regions to reveal a network-like structure of coordinate clusters (network nodes) distributed at the coactivated locations and a measure of the coactivation strength (network edges), which is determined by the presence/absence of reported activation. Here a new coordinate-based method to estimate a network of coactivations is detailed, which utilises the Z score accompanying each reported. Coordinate based meta-analysis of networks (CBMAN) assumes that if the activation pattern reported by independent studies is truly consistent, then the relative magnitude of these Z scores might also be consistent. It is hypothesised that this is detectable as Z score covariance between coactivated regions provided the within study variances are small. Advantages of using the Z scores instead of coordinates to measure coactivation strength are that censoring by the significance thresholds can be considered, and that using a continuous measure rather than a dichotomous one can increase statistical power. CBMAN uses maximum likelihood estimation to fit multivariate normal distributions to the standardised Z scores, and the covariances are considered as edges of a network of coactivated clusters (nodes). Here it is validated by numerical simulation and demonstrated on real data used previously to demonstrate CBMA. Software to perform CBMAN is freely available.

Synthesis and Biophysical Characterization of an Odd-Numbered 1,3-Diamidophospholipid.

Nanomedicine suffers from low drug delivery efficiencies. Mechanoresponsive vesicles could provide an alternative way to release active compounds triggered by the basic physics of the human body. 1,3-Diamidophospholipids with C16 tails proved to be an effective building block for mechanoresponsive vesicles, but their low main phase transition temperature prevents an effective application in humans. As the main phase transition temperature of a membrane depends on the fatty acyl chain length, we synthesized a C17 homologue of a 1,3-diamidophospholipid: Rad-PC-Rad. The elevated main phase transition temperature of Rad-PC-Rad allows mechanoresponsive drug delivery at body temperature. Herein, we report the biophysical properties of Rad-PC-Rad monolayer and bilayer membranes. Rad-PC-Rad is an ideal candidate for advancing the concept of physically triggered drug release.

Against the rules: pressure induced transition from high to reduced order.

Envisioning the next generation of drug delivery nanocontainers requires more in-depth information on the fundamental physical forces at play in bilayer membranes. In order to achieve this, we combine chemical synthesis with physical-chemical analytical methods and probe the relationship between a molecular structure and its biophysical properties. With the aim of increasing the number of hydrogen bond donors compared to natural phospholipids, a phospholipid compound bearing urea moieties has been synthesized. The new molecules form interdigitated bilayers in aqueous dispersions and self-assemble at soft interfaces in thin layers with distinctive structural order. At lower temperatures, endothermic and exothermic transitions are observed during compression. The LC1 phase is dominated by an intermolecular hydrogen bond network of the urea moieties leading to a very high chain tilt of 52°. During compression and at higher temperatures, presumably this hydrogen bond network is broken allowing a much lower chain tilt of 35°. The extremely different monolayer thicknesses violate the two-dimensional Clausius-Clapeyron equation.

Smoking Cessation and the Reduction of Disability Progression in Multiple Sclerosis: A Cohort Study.

Background: Smoking is associated with a more severe disease course in people with multiple sclerosis (MS). The magnitude of effect of smoking cessation on MS progression is unknown. The aim of this study was to quantify the impact of smoking cessation on reaching MS disability milestones. Aims and Methods: This is a cross-sectional study with retrospective reports. A comprehensive smoking questionnaire was sent to 1270 patients with MS registered between 1994 and 2013 in the Nottingham University Hospital MS Clinics database. Demographic and clinical data were extracted from the clinical database. Cox proportional hazard regression was used to estimate effects of smoke-free years on the time to Expanded Disability Status Scale (EDSS) scores 4.0 and 6.0. MS Impact Scale 29 and Patient Determined Disease Steps were used to assess the physical and psychological impact of smoking. Results: Each "smoke-free year" was associated with 0.96 (95% confidence interval: 0.95 to 0.97) times decreased risk of reaching EDSS 4.0 and 0.97 (95% confidence interval: 0.95 to 0.98) times decreased risk of reaching EDSS 6.0. Nonsmokers showed a significantly lower level of disability in all the self-reported outcomes compared with current smokers. Conclusions: The reduction in the risk of disability progression after smoking cessation is significant and time dependent. The earlier the patients quit, the stronger the reduction in the risk of reaching disability milestones. The quantitative estimates of the impact of smoking cessation on reaching disability milestones in MS can be used in interventional trials. Implications: This study provides for the first time quantitative estimates of the effects of smoking cessation in MS, essential for informing smoking cessation trials. The clear effect of smoking cessation on MS progression suggests the need to consider adjusting for smoking cessation when assessing for treatment effects in clinical trials of treatments for MS. Smoking cessation should be an early intervention in people with MS.

Coordinate based random effect size meta-analysis of neuroimaging studies.

Low power in neuroimaging studies can make them difficult to interpret, and Coordinate based meta-analysis (CBMA) may go some way to mitigating this issue. CBMA has been used in many analyses to detect where published functional MRI or voxel-based morphometry studies testing similar hypotheses report significant summary results (coordinates) consistently. Only the reported coordinates and possibly t statistics are analysed, and statistical significance of clusters is determined by coordinate density. Here a method of performing coordinate based random effect size meta-analysis and meta-regression is introduced. The algorithm (ClusterZ) analyses both coordinates and reported t statistic or Z score, standardised by the number of subjects. Statistical significance is determined not by coordinate density, but by a random effects meta-analyses of reported effects performed cluster-wise using standard statistical methods and taking account of censoring inherent in the published summary results. Type 1 error control is achieved using the false cluster discovery rate (FCDR), which is based on the false discovery rate. This controls both the family wise error rate under the null hypothesis that coordinates are randomly drawn from a standard stereotaxic space, and the proportion of significant clusters that are expected under the null. Such control is necessary to avoid propagating and even amplifying the very issues motivating the meta-analysis in the first place. ClusterZ is demonstrated on both numerically simulated data and on real data from reports of grey matter loss in multiple sclerosis (MS) and syndromes suggestive of MS, and of painful stimulus in healthy controls. The software implementation is available to download and use freely.

Prevalence of a history of prior varicella/herpes zoster infection in multiple sclerosis.

Varicella zoster virus (VZV) infection has been implicated in multiple sclerosis (MS), but direct causal involvement has been disputed. Nevertheless, knowledge of VZV exposure is important, given the risk of serious complications of first exposure while undergoing immunosuppressive treatment, in particular with fingolimod. We distributed questionnaires to MS clinic patients, requesting information about history of chickenpox, sibling/household/occupational exposure, history of zoster (shingles), and disease-modifying treatment. A random, proportionally representative sample of 51 patients that included patients with positive, negative, and unknown chickenpox history were selected for determination of VZV IgG by ELISA. Of 1206 distributed questionnaires, 605 were returned (50% response rate). Of these, 86% reported history of chickenpox, 5.6% gave negative history, and 8.5% did not know. Of 594 who answered the zoster question, 78% gave a negative response, 4% did not know, and 104 (17%) answered yes. Of these, 83 reported 1 episode; 12 had 2; 5 had 3; and 1 each reported 5, 6, and 15 episodes. Of 51 patients tested for VZV IgG (44 "yes," 4 "no," and 3 "I don't know" answers to the question of whether they had chickenpox), 48 were seropositive; the 3 seronegative all had reported having had chickenpox. The high rate of MS patients reporting prior chickenpox infection is comparable with previous reports. A substantial proportion of MS patients, estimated to be higher than an age-matched general population, report single or multiple episodes of zoster. These data are useful for consideration of immunosuppressive treatments and/or VZV and zoster vaccination.

Human endogenous retroviruses and multiple sclerosis: Causation, association, or after-effect?

From the early days of MS discovery, infections have been proposed as a possible cause of the disease. In the last three decades, an association between human endogenous retrovirus expression and MS has been further investigated and confirmed. Nevertheless, the role of such retroviruses in the disease needs clarification. In this review, we introduce MSRV/HERV-W and describe its association with MS. We then summarize the evidence for the involvement of MSRV/HERV-W in the aetiology and progression of MS and its possible role as biomarker and drug target. Biological mechanisms for HERV effects in MS may involve the activation of innate immune pathways by the envelope protein of MSRV (MSRVEnv). In addition to in vitro and experimental studies, further insight on how HERVs may influence immune-mediated pathology in MS may also come from the use of antiretroviral treatments in patients.

Vesicle Origami: Cuboid Phospholipid Vesicles Formed by Template-Free Self-Assembly.

Phospholipid liposomes are archetypical self-assembled structures. To minimize the surface tension, the vesicles typically are spherical. Deciphering the bilayer code, the basic physical interactions between phospholipids would allow these molecules to be utilized as building blocks for novel, non-spherical structures. A 1,2-diamidophospholipid is presented that self-assembles into a cuboid structure. Owing to intermolecular hydrogen bonding, the bilayer membranes form an exceptionally tight subgel packing, leading to a maximization of flat structural elements and a minimization of any edges. These conditions are optimized in the geometrical structure of a cube. Surprisingly, the lateral surface pressure in the membrane is only one third of the value typically assumed for a bilayer membrane, questioning a long-standing rule-of-thumb.

Mortality in multiple sclerosis: meta-analysis of standardised mortality ratios.

OBJECTIVE: There are inconsistent data on mortality in people with multiple sclerosis (MS). We performed a meta-analysis of all-cause, cause-specific and gender-specific crude mortality rates (CMRs), and standardised mortality ratios (SMRs) in MS, and estimated the rate of change of CMR and SMR over the past 50 years. METHODS: Medline, Embase and the Cochrane Library were searched. KEYWORDS: 'Multiple Sclerosis' and ('standardised mortality' or 'standardized mortality'). INCLUSION CRITERIA: availability of data on the number of deaths; mean or median patient follow-up or reports of SMRs; being a longitudinal study. 12 studies were included covering the period 1949-2012 (27 423 patients; 6628 deaths; 437 832 person-years follow-up). CMR was calculated. SMRs were extracted. CMRs and natural logarithm of SMRs were pooled by the method of the inverse of the variance. Meta-regression models were used to investigate the secular trends. RESULTS: Pooled CMR was 9.78/1000 person-years (95% CI 6.81 to 14.02). Pooled all-cause SMR was 2.80 (95% CI 2.74 to 2.87). All-cause SMR was 2.56 (95% CI 2.47 to 2.66) in males and 3.06 (95% CI 2.97 to 3.17) in females. SMR due to cancer was 0.89 (95% CI 0.83 to 0.97). SMRs due to cardiovascular diseases, suicide, infection and respiratory diseases were 1.29 (95% CI 1.20 to 1.38), 2.13 (95% CI 1.80 to 2.51) and 2.91 (95% CI 2.60 to 3.26). There was no trend in CMRs, all-cause, and gender-specific SMRs. CONCLUSIONS: The excess mortality in MS relative to the general population has not changed over the past 50 years. Female patients with MS have higher survival disadvantage compared to that of males. Death due to cardiovascular diseases, suicide and infection is higher in patients with MS compared to the general population.

Vesicle Origami and the Influence of Cholesterol on Lipid Packing.

The artificial phospholipid Pad-PC-Pad was analyzed in 2D (monolayers at the air/water interface) and 3D (aqueous lipid dispersions) systems. In the gel phase, the two leaflets of a Pad-PC-Pad bilayer interdigitate completely, and the hydrophobic bilayer region has a thickness comparable to the length of a single phospholipid acyl chain. This leads to a stiff membrane with no spontaneous curvature. Forced into a vesicular structure, Pad-PC-Pad has faceted geometry, and in its extreme form, tetrahedral vesicles were found as predicted a decade ago. Above the main transition temperature, a noninterdigitated Lα phase with fluid chains has been observed. The addition of cholesterol leads to a slight decrease of the main transition temperature and a gradual decrease in the transition enthalpy until the transition vanishes at 40 mol % cholesterol in the mixture. Additionally, cholesterol pulls the chains apart, and a noninterdigitated gel phase is observed. In monolayers, cholesterol has an ordering effect on liquid-expanded phases and disorders condensed phases. The wavenumbers of the methylene stretching vibration indicate the formation of a liquid-ordered phase in mixtures with 40 mol % cholesterol.

Bilayer properties of 1,3-diamidophospholipids.

A series of 1,3-diamido phosphocholines was synthesized, and their potential to form stable bilayers was investigated. Large and giant unilamellar vesicles produced from these new lipids form a wide variety of faceted liposomes. Factors such as cooling rates and the careful choice of the liposome preparation method influence the formation of facets. Interdigitation was hypothesized as a main factor for the stabilization of facets and effectively monitored by small-angle X-ray scattering measurements.

Ocrelizumab B cell depletion has no effect on HERV RNA expression in PBMC in MS patients.

BACKGROUND: Epstein barr virus (EBV) infection of B cells is now understood to be one of the triggering events for the development of Multiple Sclerosis (MS), a progressive immune-mediated disease of the central nervous system. EBV infection is also linked to expression of human endogenous retroviruses (HERVs) of the HERV-W group, a further risk factor for the development of MS. Ocrelizumab is a high-potency disease-modifying treatment (DMT) for MS, which depletes B cells by targeting CD20. OBJECTIVES: We studied the effects of ocrelizumab on gene expression in peripheral blood mononuclear cells (PBMC) from paired samples from 20 patients taken prior to and 6 months after beginning ocrelizumab therapy. We hypothesised that EBV and HERV-W loads would be lower in post-treatment samples. METHODS: Samples were collected in Paxgene tubes, subject to RNA extraction and Illumina paired end short read mRNA sequencing with mapping of sequence reads to the human genome using Salmon and differential gene expression compared with DeSeq2. Mapping was also performed separately to the HERV-D database of HERV sequences and the EBV reference sequence. RESULTS: Patient samples were more strongly clustered by individual rather than disease type (relapsing/remitting or primary progressive), treatment (pre and post), age, or sex. Fourteen genes, all clearly linked to B cell function were significantly down regulated in the post treatment samples. Interestingly only one pre-treatment sample had detectable EBV RNA and there were no significant differences in HERV expression (of any group) between pre- and post-treatment samples. CONCLUSIONS: While EBV and HERV expression are clearly linked to triggering MS pathogenesis, it does not appear that high level expression of these viruses is a part of the ongoing disease process or that changes in virus load are associated with ocrelizumab treatment.