Long-term management of natalizumab discontinuation in a large monocentric cohort of multiple sclerosis patients

Background Pivotal and post-marketing studies demonstrated the impressive efficacy and the good tolerability profile of natalizumab in Multiple Sclerosis patients. On the other hand long-term safety of natalizumab therapy is burdened by the risk of progressive multifocal leukoencephalopathy, especially in anti-JCV seropositive patients treated for more than two years. Some of these patients must stop the drug at the risk of disease reactivation. Objectives To evaluate the effects of natalizumab discontinuation in a monocentric cohort of multiple sclerosis patients followed for a mean time of 22.4 months. Methods One hundred and ten patients, who stopped therapy after at least 12 infusions, were followed with periodic clinical and magnetic resonance imaging evaluations. One hundred patients started either immunomodulant therapy (n=90) or fingolimod (n=10) while 10 remained without any drug. Results "Disease-activity free" patients were 25% at one year after discontinuation and annualized relapse rate significantly increased from 0.06 to 0.84 (p<0.0001). We found that the risk of reactivation peaked despite alternative treatments between the second and the eighth month after suspension, a so-called "high risk period". During this period the majority of patients showed a return to pre-natalizumab disease activity while 10% of patients presented a "rebound activity". A higher pre-natalizumab disease activity was correlated with an increased risk of reactivation (p=0.004). Conclusions Our data suggest that disease reactivation peaked during a "high risk period" between the second and the eighth month since stopping the drug. During this period no alternative treatments seemed to provide an adequate protection from disease reactivation. Though transient, this phase could be potentially dangerous, therefore we need to develop more effective strategies to deal with this challenge

Mitoxantrone for multiple sclerosis

BACKGROUND: This is an updated Cochrane review of the previous published version.Mitoxantrone (MX) has been shown to be moderately effective in reducing the clinical outcome measures of disease activity in multiple sclerosis (MS) patients. OBJECTIVES: The main objective was to assess the efficacy and safety of MX compared to a control group in relapsing-remitting (RRMS), progressive relapsing (PRMS) and secondary progressive (SPMS) MS participants. SEARCH METHODS: We searched the Cochrane Multiple Sclerosis and Rare Diseases of the Central Nervous System Group Specialised Register (June 2012) and reference lists of articles. We also undertook handsearching and contacted trialists and pharmaceutical companies. SELECTION CRITERIA: Randomised, double-blinded, controlled trials (RCTs) comparing the administration of MX versus placebo or MX plus steroids treatment versus placebo plus steroids treatment were included. DATA COLLECTION AND ANALYSIS: The review authors independently selected articles for inclusion. They independently extracted clinical, safety and magnetic resonance imaging (MRI) data, resolving disagreements by discussion. Risk of bias was evaluated to assess the quality of the studies. Treatment effect was measured using odds ratios (OR) with 95% confidence intervals (CI) for the binary outcomes and mean differences (MD) with 95% CI for the continuous outcomes. If heterogeneity was absent, a fixed-effect model was used. MAIN RESULTS: Three trials were selected and 221 participants were included in the analyses. MX reduced the progression of disability at two years follow-up (proportion of participants with six months confirmed progression of disability (OR 0.30, 95% CI 0.09 to 0.99 and MD -0.36, 95% CI- 0.70 to -0.02; P = 0.04)). Significant results were found regarding the reduction in annualised relapse rate (MD -0.85, 95% CI -1.47 to -0.23; P = 0.007), the proportion of patients free from relapses at one year (OR 7.13, 95% CI 2.06 to 24.61; P = 0.002) and two years (OR 2.82, 95% CI 1.54 to 5.19; P = 0.0008), and the number of patients with active MRI lesions at six months or one year only (OR 0.24, 95% CI 0.10 to 0.57; P = 0.001). Side effects reported in the trials (amenorrhoea, nausea and vomiting, alopecia and urinary tract infections) were more frequent in treated patients than in controls, while no major adverse events have been reported. These results should be considered with caution because of the heterogeneous characteristics of included trials in term of drug dosage, inclusion criteria and quality of included trials. Moreover, it was not possible to estimate the long-term efficacy and safety of MX. AUTHORS' CONCLUSIONS: MX shows a significant but partial efficacy in reducing the risk of MS progression and the frequency of relapses in patients affected by worsening RRMS, PRMS and SPMS in the short-term follow-up (two years). No major neoplastic events or symptomatic cardiotoxicity related to MX have been reported; however studies with longer follow-up (not included in this review) have raised concerns about the risk of systolic disfunction (\u2dc12%) and therapy-related acute leukaemias (0.8%), which are increasingly reported in the literature.MX should be limited to treating patients with worsening RRMS and SPMS and with evidence of persistent inflammatory activity after a careful assessment of the individual patients' risk and benefit profiles. Assessment should also consider the present availability of alternative therapies with less severe adverse events

Autologous hematopoietic cell transplantation in multiple sclerosis.

INTRODUCTION: Autologous haematopoietic cell transplantation (AHCT) is an evolving treatment avenue in multiple sclerosis (MS), which may be highly effective in controlling disease activity and improving disability. However, AHCT is associated with intrinsic toxicities and risks compared with conventional therapies. With growing experience in patient selection and treatment delivery, AHCT is increasingly considered an option in patients with aggressive disease that's responding poorly to disease modifying therapy. AREAS COVERED: This article provides an introduction to AHCT and looks at its development as a treatment for MS over the last 20 years. It also highlights potential mechanisms of action, patient selection, and future trends for this treatment approach. EXPERT OPINION: Currently published data suggest that AHCT's use is associated with significant reduction in MS disease activity and marked improvement in disability when used in patients with highly active relapsing remitting disease. Its long term safety and efficacy have not been fully evaluated but as increasing clinical trial data are published, its use is likely to grow. Further randomised controlled studies are needed to compare AHCT with standard disease modifying therapies and to optimise transplant regimens. Mechanistic studies may provide potential markers for response and a better understanding of disease pathogenesis

Contribution of Rare and Low-Frequency Variants to Multiple Sclerosis Susceptibility in the Italian Continental Population

Genome-wide association studies identified over 200 risk loci for multiple sclerosis (MS) focusing on common variants, which account for about 50% of disease heritability. The goal of this study was to investigate whether low-frequency and rare functional variants, located in MS-established associated loci, may contribute to disease risk in a relatively homogeneous population, testing their cumulative effect (burden) with gene-wise tests. We sequenced 98 genes in 588 Italian patients with MS and 408 matched healthy controls (HCs). Variants were selected using different filtering criteria based on allelic frequency and in silico functional impacts. Genes showing a significant burden (n = 17) were sequenced in an independent cohort of 504 MS and 504 HC. The highest signal in both cohorts was observed for the disruptive variants (stop-gain, stop-loss, or splicing variants) located in EFCAB13, a gene coding for a protein of an unknown function (p &lt; 10–4). Among these variants, the minor allele of a stop-gain variant showed a significantly higher frequency in MS versus HC in both sequenced cohorts (p = 0.0093 and p = 0.025), confirmed by a meta-analysis on a third independent cohort of 1298 MS and 1430 HC (p = 0.001) assayed with an SNP array. Real-time PCR on 14 heterozygous individuals for this variant did not evidence the presence of the stop-gain allele, suggesting a transcript degradation by non-sense mediated decay, supported by the evidence that the carriers of the stop-gain variant had a lower expression of this gene (p = 0.0184). In conclusion, we identified a novel low-frequency functional variant associated with MS susceptibility, suggesting the possible role of rare/low-frequency variants in MS as reported for other complex diseases

Impact of multiple sclerosis risk loci in postinfectious neurological syndromes

Background: The genetic component of multiple sclerosis (MS) is now set to 200 autosomal common variants. However, it is unclear how genetic knowledge be clinically used in the differential diagnosis between MS and other inflammatory conditions like adult-onset postinfectious neurological syndromes (PINS). The aim of this study was to investigate whether PINS and MS have a shared genetic background using an updated polygenic risk scores. / Methods: Eighty-eight PINS patients have been consecutively recruited between 1996 and 2016 at Mondino Foundation of Pavia, diagnosed according to clinical, MRI and CSF findings and followed-up for several years. Patients were typed using Illumina array, and genotypes imputed using the 1000 Genomes Project reference panel. A weighted genetic risk score (wGRS) has been calculated based on autosomal MS risk loci derived from large-scale studies, and an HLA genetic burden (HLAGB) was also calculated on loci associated to MS. / Results: PINS occurred as an episode of myelitis in 44% of patients, encephalomyelitis in 44%, and encephalitis in remaining cases, with an involvement of peripheral nervous system in 41% of patients. Mean age of onset was 50.1 years, and female:male ratio was 1.4. Patients were followed-up for a mean of 7.2 years, and at last visit 55% had a low disability grade (mRS 0–1). Disease was monophasic in 67% of patients, relapsing in 18% and chronic-progressive in 15%. The wGRS of PINS cases was comparable to 370 healthy controls, while significantly lower compared to 907 bout-onset MS (BOMS) cases (wGRS= 20.9 vs 21.2; p<0.0001). The difference was even larger for PINS with peripheral nervous system involvement (wGRS=20.6) vs BOMS. / Conclusion: The distinction between MS and PINS is not easy to make in clinical practice. However, our study shows that the new set of MS risk alleles does not confer increased susceptibility to PINS. These data support the importance to discriminate these cases from MS with pathophysiological and therapeutic implications

Next generation sequencing of pooled samples : guideline for variants&apos; filtering

Sequencing large number of individuals, which is often needed for population genetics studies, is still economically challenging despite falling costs of Next Generation Sequencing (NGS). Pool-seq is an alternative cost- and time-effective option in which DNA from several individuals is pooled for sequencing. However, pooling of DNA creates new problems and challenges for accurate variant call and allele frequency (AF) estimation. In particular, sequencing errors confound with the alleles present at low frequency in the pools possibly giving rise to false positive variants. We sequenced 996 individuals in 83 pools (12 individuals/pool) in a targeted re-sequencing experiment. We show that Pool-seq AFs are robust and reliable by comparing them with public variant databases and in-house SNP-genotyping data of individual subjects of pools. Furthermore, we propose a simple filtering guideline for the removal of spurious variants based on the Kolmogorov-Smirnov statistical test. We experimentally validated our filters by comparing Pool-seq to individual sequencing data showing that the filters remove most of the false variants while retaining majority of true variants. The proposed guideline is fairly generic in nature and could be easily applied in other Pool-seq experiments

Early involvement of cellular stress and inflammatory signals in the pathogenesis of tubulointerstitial kidney disease due to UMOD mutations

Autosomal dominant tubulointerstitial kidney disease (ADTKD) is an inherited disorder that causes progressive kidney damage and renal failure. Mutations in the UMOD gene, encoding uromodulin, lead to ADTKD-UMOD related. Uromodulin is a GPI-anchored protein exclusively produced by epithelial cells of the thick ascending limb of Henle's loop. It is released in the tubular lumen after proteolytic cleavage and represents the most abundant protein in human urine in physiological condition. We previously generated and characterized a transgenic mouse model expressing mutant uromodulin (TgUmodC147W) that recapitulates the main features of ATDKD-UMOD. While several studies clearly demonstrated that mutated uromodulin accumulates in endoplasmic reticulum, the mechanisms that lead to renal damage are not fully understood. In our work, we used kidney transcriptional profiling to identify early events of pathogenesis in the kidneys of TgUmodC147Wmice. Our results demonstrate up-regulation of inflammation and fibrosis and down-regulation of lipid metabolism in young TgUmodC147Wmice, before any functional or histological evidence of kidney damage. We also show that pro-inflammatory signals precede fibrosis onset and are already present in the first week after birth. Early induction of inflammation is likely relevant for ADTKD-UMOD pathogenesis and related pathways can be envisaged as possible novel targets for therapeutic intervention

NLRP3 polymorphisms and response to interferon-beta in multiple sclerosis patients

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