0000000000174531

AUTHOR

Xavier Montalban

0000-0002-0098-9918

Power estimation for non-standardized multisite studies

A concern for researchers planning multisite studies is that scanner and T1-weighted sequence-related biases on regional volumes could overshadow true effects, especially for studies with a heterogeneous set of scanners and sequences. Current approaches attempt to harmonize data by standardizing hardware, pulse sequences, and protocols, or by calibrating across sites using phantom-based corrections to ensure the same raw image intensities. We propose to avoid harmonization and phantom-based correction entirely. We hypothesized that the bias of estimated regional volumes is scaled between sites due to the contrast and gradient distortion differences between scanners and sequences. Given this…

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Genome-wide significant association of ANKRD55 rs6859219 and multiple sclerosis risk.

Multiple sclerosis (MS) is a genetically complex disease that shares a substantial proportion of risk loci with other autoimmune diseases.1 Along these lines, ANKRD55 , originally implicated in rheumatoid arthritis, was recently reported as a potential novel MS risk gene (rs6859219, p=1.9×10−7).2 Here, we comprehensively validated this effect in independent datasets comprising 8846 newly genotyped subjects from Germany and France as well as 5003 subjects from two genome-wide association studies (GWAS). Upon meta-analysis of all available data (19 686 subjects), ANKRD55 rs6859219 now shows compelling evidence for association with MS at genome-wide significance (OR=1.19, p=3.1×10−11). Our stu…

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PML risk stratification using anti-JCV antibody index and L-selectin

Background: Natalizumab treatment is associated with progressive multifocal leukoencephalopathy (PML) development. Treatment duration, prior immunosuppressant use, and JCV serostatus are currently used for risk stratification, but PML incidence stays high. Anti-JCV antibody index and L-selectin (CD62L) have been proposed as additional risk stratification parameters. Objective: This study aimed at verifying and integrating both parameters into one algorithm for risk stratification. Methods: Multicentric, international cohorts of natalizumab-treated MS patients were assessed for JCV index (1921 control patients and nine pre-PML patients) and CD62L (1410 control patients and 17 pre-PML patient…

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Clinical Efficacy of Laquinimod for the Treatment of Multiple Sclerosis; Pooled Analyses from the ALLEGRO and BRAVO Phase III Trials (S01.007)

Objective: The current report provides detail on pooled analyses assessing the effect of laquinimod on relapse, disability, and brain atrophy measures from the recently completed phase III trials ALLEGRO and BRAVO. Background Laquinimod is an oral, CNS acting immunomodulator in development for the treatment of multiple sclerosis. Its impact on disability progression and brain atrophy, two indices of longterm outcome for patients with multiple sclerosis (MS) are being studied in its phase III trials. Design/Methods: MS patients (N=2437) were randomized to laquinimod (n=984) or placebo (n = 1006). In both trials, patients underwent neurological examinations including the Expanded Disability S…

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Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis.

Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have ena…

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Multiple sclerosis severity score: Using disability and disease duration to rate disease severity

Background: There is no consensus method for determining progression of disability in patients with multiple sclerosis (MS) when each patient has had only a single assessment in the course of the disease. Methods: Using data from two large longitudinal databases, the authors tested whether cross-sectional disability assessments are representative of disease severity as a whole. An algorithm, the Multiple Sclerosis Severity Score (MSSS), which relates scores on the Expanded Disability Status Scale (EDSS) to the distribution of disability in patients with comparable disease durations, was devised and then applied to a collection of 9,892 patients from 11 countries to create the Global MSSS. I…

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Genome-wide significant association with seven novel multiple sclerosis risk loci

Objective A recent large-scale study in multiple sclerosis (MS) using the ImmunoChip platform reported on 11 loci that showed suggestive genetic association with MS. Additional data in sufficiently sized and independent data sets are needed to assess whether these loci represent genuine MS risk factors. Methods The lead SNPs of all 11 loci were genotyped in 10 796 MS cases and 10 793 controls from Germany, Spain, France, the Netherlands, Austria and Russia, that were independent from the previously reported cohorts. Association analyses were performed using logistic regression based on an additive model. Summary effect size estimates were calculated using fixed-effect meta-analysis. Results…

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Heterogeneity at the HLA-DRB1 locus and risk for multiple sclerosis.

Variation in major histocompatibility complex genes on chromosome 6p21.3, specifically the human leukocyte antigen HLA-DR2 or DRB1*1501-DQB1*0602 extended haplotype, confers risk for multiple sclerosis (MS). Previous studies of DRB1 variation and both MS susceptibility and phenotypic expression have lacked statistical power to detect modest genotypic influences, and have demonstrated conflicting results. Results derived from analyses of 1339 MS families indicate DRB1 variation influences MS susceptibility in a complex manner. DRB1*15 was strongly associated in families (P=7.8x10(-31)), and a dominant DRB1*15 dose effect was confirmed (OR=7.5, 95% CI=4.4-13.0, P<0.0001). A modest dose effect…

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Lack of efficacy of mitoxantrone in primary progressive Multiple Sclerosis irrespective of pharmacogenetic factors: A multi-center, retrospective analysis

Abstract Background Mitoxantrone is used on an off-label basis in primary progressive MS (PPMS). ABC -transporter-genotypes are associated with therapeutic response in relapsing/secondary progressive MS (RP/SPMS). Objective To evaluate potential pharmacogenetic response markers for mitoxantrone in PPMS. Methods 41 mitoxantrone-treated PPMS-patients, 155 mitoxantrone-treated RP/SPMS-patients and 43 PPMS-controls were retrospectively assessed for clinical therapy-response and in correlation with four single-nucleotide-polymorphisms in ABCB1 - and ABCG2 -genes. Results 53.7% PPMS-patients were mitoxantrone-responders, in comparison to 78.1% of RP/SPMS-patients (p = 0.039). There was no associa…

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Low frequency and rare coding variation contributes to multiple sclerosis risk

AbstractMultiple sclerosis is a common, complex neurological disease, where almost 20% of risk heritability can be attributed to common genetic variants, including &gt;230 identified by genome-wide association studies (Patsopoulos et al., 2017). Multiple strands of evidence suggest that the majority of the remaining heritability is also due to the additive effects of individual variants, rather than epistatic interactions between these variants, or mutations exclusive to individual families. Here, we show in 68,379 cases and controls that as much as 5% of this heritability is explained by low-frequency variation in gene coding sequence. We identify four novel genes driving MS risk independe…

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The Multiple Sclerosis Genomic Map: Role of peripheral immune cells and resident microglia in susceptibility

Abstract:We assembled and analyzed genetic data of 47,351 multiple sclerosis (MS) subjects and 68,284 control subjects and establish a reference map of the genetic architecture of MS that includes 200 autosomal susceptibility variants outside the major histocompatibility complex (MHC), one chromosome X variant, and 32 independent associations within the extended MHC. We used an ensemble of methods to prioritize up to 551 potentially associated MS susceptibility genes, that implicate multiple innate and adaptive pathways distributed across the cellular components of the immune system. Using expression profiles from purified human microglia, we do find enrichment for MS genes in these brain -…

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The Rare IL22RA2 Signal Peptide Coding Variant rs28385692 Decreases Secretion of IL-22BP Isoform-1, -2 and -3 and Is Associated with Risk for Multiple Sclerosis

The IL22RA2 locus is associated with risk for multiple sclerosis (MS) but causative variants are yet to be determined. In a single nucleotide polymorphism (SNP) screen of this locus in a Basque population, rs28385692, a rare coding variant substituting Leu for Pro at position 16 emerged significantly (p = 0.02). This variant is located in the signal peptide (SP) shared by the three secreted protein isoforms produced by IL22RA2 (IL-22 binding protein-1(IL-22BPi1), IL-22BPi2 and IL-22BPi3). Genotyping was extended to a Europe-wide case-control dataset and yielded high significance in the full dataset (p = 3.17 &times

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Diagnosis of multiple sclerosis: a multicentre study to compare revised McDonald-2010 and Filippi-2010 criteria

MRI has been formally included in the diagnostic work-up of patients with a suspicion of multiple sclerosis (MS) in 2001, to demonstrate disease dissemination in space (DIS) and time (DIT) and to exclude alternative diagnoses.1 Over time, these criteria have been modified to simplify their use and to clarify specific aspects (eg, spinal cord findings).2 One aspect marginally analysed in the diagnostic work-up of patients with clinically isolated syndrome (CIS) is the role of intracortical lesions (ICLs), which are a prominent feature of MS and contribute to disability and cognitive impairment.2 A single-centre study3 showed that inclusion of ICL for the evaluation of DIS in CIS increased th…

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ECTRIMS/EAN guideline on the pharmacological treatment of people with multiple sclerosis.

Background and purpose: Multiple sclerosis (MS) is a complex disease of the central nervous system. As new drugs are becoming available, knowledge on diagnosis and treatment must continuously evolve. There is therefore a need for a reference tool compiling current data on benefit and safety, to aid professionals in treatment decisions and use of resources across Europe. The European Committee of Treatment and Research in Multiple Sclerosis (ECTRIMS) and the European Academy of Neurology (EAN) have joined forces to meet this need. The objective was to develop an evidence-based clinical practice guideline for the pharmacological treatment of people with MS to guide healthcare professionals in…

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Analysis of Plasminogen Genetic Variants in Multiple Sclerosis Patients.

Multiple sclerosis (MS) is a prevalent neurological disease of complex etiology. Here, we describe the characterization of a multi-incident MS family that nominated a rare missense variant (p.G420D) in plasminogen (PLG) as a putative genetic risk factor for MS. Genotyping of PLG p.G420D (rs139071351) in 2160 MS patients, and 886 controls from Canada, identified 10 additional probands, two sporadic patients and one control with the variant. Segregation in families harboring the rs139071351 variant, identified p.G420D in 26 out of 30 family members diagnosed with MS, 14 unaffected parents, and 12 out of 30 family members not diagnosed with disease. Despite considerably reduced penetrance, lin…

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