A recent genome-wide association study reported five loci for which there was strong, but sub-genome-wide significant evidence for association with multiple sclerosis risk. The aim of this study was to evaluate the role of these potential risk loci in a large and independent data set of ∼20 000 subjects. We tested five single nucleotide polymorphisms rs228614 (MANBA), rs630923 (CXCR5), rs2744148 (SOX8), rs180515 (RPS6KB1), and rs6062314 (ZBTB46) for association with multiple sclerosis risk in a total of 8499 cases with multiple sclerosis, 8765 unrelated control subjects and 958 trios of European descent. In addition, we assessed the overall evidence for association by combining these newly generated data with the results from the original genome-wide association study by meta-analysis. All five tested single nucleotide polymorphisms showed consistent and statistically significant evidence for association with multiple sclerosis in our validation data sets (rs228614: odds ratio = 0.91, P = 2.4 × 10−6; rs630923: odds ratio = 0.89, P = 1.2 × 10−4; rs2744148: odds ratio = 1.14, P = 1.8 × 10−6; rs180515: odds ratio = 1.12, P = 5.2 × 10−7; rs6062314: odds ratio = 0.90, P = 4.3 × 10−3). Combining our data with results from the previous genome-wide association study by meta-analysis, the evidence for association was strengthened further, surpassing the threshold for genome-wide significance (P < 5 × 10−8) in each case. Our study provides compelling evidence that these five loci are genuine multiple sclerosis susceptibility loci. These results may eventually lead to a better understanding of the underlying disease pathophysiology.
multiple sclerosis; complex genetics; genetic risk; immunogenetics; genetic association
The prevalence of multiple sclerosis (MS) is now considered to be medium-to-high in the Middle East and is rising, particularly among women. While the characteristics of the disease and the response of patients to disease-modifying therapies are generally comparable between the Middle East and other areas, significant barriers to achieving optimal care for MS exist in these developing nations. A group of physicians involved in the management of MS in ten Middle Eastern countries met to consider the future of MS care in the region, using a structured process to reach a consensus. Six key priorities were identified: early diagnosis and management of MS, the provision of multidisciplinary MS centres, patient engagement and better communication with stakeholders, regulatory body education and reimbursement, a commitment to research, and more therapy options with better benefit-to-risk ratios. The experts distilled these priorities into a single vision statement: “Optimization of patient-centred multidisciplinary strategies to improve the quality of life of people with MS.” These core principles will contribute to the development of a broader consensus on the future of care for MS in the Middle East.
The epidemiology of multiple sclerosis (MS) is rapidly changing in many parts of the world. Based on the Kurtzke classification, the Arabian Gulf Region is located in a low-risk zone for MS; however, recent studies suggest a moderate-to-high prevalence nearby (31–55 MS per 10,0000 individuals), with an increase in incidence in recent years. The relapsing-remitting disease course ratio is 2.5:1 versus the primary progressive type. In a geographic area that was previously associated with low prevalence; the recent high prevalence and fast rising incidence of MS in the gulf countries, encouraged the neurologists of this region to meet in a consensus panel, in order to share our latest findings in terms of MS epidemiology and consent on MS management in the Arabian Gulf. Therefore 20 key opinion leader neurologists and MS experts representing various countries of the Arabian Gulf have met in Dubai on the 2 and 3 February 2012, they shared their latest epidemiological findings, discussed recent MS aspects in the region, and consented on MS management relevantly to this geographic area.
Multiple sclerosis; Diagnosis; Treatment; Guidelines; Arabian Gulf
Compensation of brain injury in multiple sclerosis (MS) may in part work through mechanisms involving neuronal plasticity on local and interregional scales. Mechanisms limiting excessive neuronal activity may have special significance for retention and (re-)acquisition of lost motor skills in brain injury. However, previous neurophysiological studies of plasticity in MS have investigated only excitability enhancing plasticity and results from neuroimaging are ambiguous. Thus, the aim of this study was to probe long-term depression-like central motor plasticity utilizing continuous theta-burst stimulation (cTBS), a non-invasive brain stimulation protocol. Because cTBS also may trigger behavioral effects through local interference with neuronal circuits, this approach also permitted investigating the functional role of the primary motor cortex (M1) in force control in patients with MS.
We used cTBS and force recordings to examine long-term depression-like central motor plasticity and behavioral consequences of a M1 lesion in 14 patients with stable mild-to-moderate MS (median EDSS 1.5, range 0 to 3.5) and 14 age-matched healthy controls. cTBS consisted of bursts (50 Hz) of three subthreshold biphasic magnetic stimuli repeated at 5 Hz for 40 s over the hand area of the left M1. Corticospinal excitability was probed via motor-evoked potentials (MEP) in the abductor pollicis brevis muscle over M1 before and after cTBS. Force production performance was assessed in an isometric right thumb abduction task by recording the number of hits into a predefined force window.
cTBS reduced MEP amplitudes in the contralateral abductor pollicis brevis muscle to a comparable extent in control subjects (69 ± 22% of baseline amplitude, p < 0.001) and in MS patients (69 ± 18%, p < 0.001). In contrast, post-cTBS force production performance was only impaired in controls (2.2 ± 2.8, p = 0.011), but not in MS patients (2.0 ± 4.4, p = 0.108). The decline in force production performance following cTBS correlated with corticomuscular latencies (CML) in MS patients, but did not correlate with MEP amplitude reduction in patients or controls.
Long-term depression-like plasticity remains largely intact in mild-to-moderate MS. Increasing brain injury may render the neuronal networks less responsive toward lesion-induction by cTBS.
Multiple sclerosis; LTD; Motor plasticity; TMS; Motor cortex
The “MS in the 21st Century” initiative was established with the purpose of (1) defining how multiple sclerosis (MS) treatment and standards of care should look in the 21st century; (2) developing a minimum standard of care across the world; and (3) motivating the broad MS community to align standards of care and challenge the current treatment paradigm. The aim was to develop a consensus statement to reach and influence the broader MS community. An expert steering group from Europe and Canada—consisting of neurologists, patient advocates, a pharmacoepidemiologist/pharmacoeconomist, and representatives from national MS centers—participated in a series of workshop-driven meetings between February 2011 and 2012. After three phases of discussions, the steering group identified that the overall vision for future care of MS should be full access to personalized treatment, with reimbursement, to achieve freedom from disease. They constructed seven overall principles that support this vision: personalized care, patient engagement, commitment to research, regulatory body education and reimbursement issues, new endpoints in clinical trials, more therapy options, and MS centers of excellence. This consensus statement outlines the key aspects of the seven principles that need to be addressed. The “MS in the 21st Century Steering Group” hopes that this consensus statement acts as a call to action for healthcare providers and decision-makers to address simultaneously the overarching principles that will guide patient management in order to improve outcomes for people with MS.
Multiple sclerosis; Care; Management; Consensus statement
The purpose of this study was to investigate the modification of expression and functionality of the drug transporter P-glycoprotein (P-gp) by tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ) at the blood-brain barrier (BBB). We used immortalized human brain microvessel endothelial cells (iHBMEC) and primary human brain microvessel endothelial cells (pHBMEC) as in vitro BBB model. To investigate the change of p-gp expression, we carried out real time PCR analysis and Western blotting. To test the change of p-gp activity, we performed rhodamin123 (Rh123) accumulation study in the cells. In results of real time PCR analysis, the P-gp mRNA expression was increased by TNF-α or IFN-γ treatment for 24 hr in both cell types. However, 48 hr treatment of TNF-α or IFN-γ did not affect P-gp mRNA expression. In addition, co-treatment of TNF-α and IFN-γ markedly increased the P-gp mRNA expression in both cells. TNF-α or IFN-γ did not influence P-gp protein expression whatever the concentration of cytokines or duration of treatment in both cells. However, P-gp expression was increased after treatments of both cytokines together in iHBMEC cells only compared with untreated control. Furthermore, in both cell lines, TNF-α or IFN-γ induced significant decrease of P-gp activity for 24 hr treatment. And, both cytokines combination treatment also decreased significantly P-gp activity. These results suggest that P-gp expression and function at the BBB is modulated by TNF-α or/and IFN-γ. Therefore, the distribution of P-gp depending drugs in the central nervous system can be modulated by neurological inflammatory diseases.
TNF-α; IFN-γ; P-glycoprotein; Human brain microvascular endothelial cell; Blood-brain barrier; Efflux transport
Detection of epistatic interaction between loci has been postulated to provide a more in-depth understanding of the complex biological and biochemical pathways underlying human diseases. Studying the interaction between two loci is the natural progression following traditional and well-established single locus analysis. However, the added costs and time duration required for the computation involved have thus far deterred researchers from pursuing a genome-wide analysis of epistasis. In this paper, we propose a method allowing such analysis to be conducted very rapidly. The method, dubbed EPIBLASTER, is applicable to case–control studies and consists of a two-step process in which the difference in Pearson's correlation coefficients is computed between controls and cases across all possible SNP pairs as an indication of significant interaction warranting further analysis. For the subset of interactions deemed potentially significant, a second-stage analysis is performed using the likelihood ratio test from the logistic regression to obtain the P-value for the estimated coefficients of the individual effects and the interaction term. The algorithm is implemented using the parallel computational capability of commercially available graphical processing units to greatly reduce the computation time involved. In the current setup and example data sets (211 cases, 222 controls, 299468 SNPs; and 601 cases, 825 controls, 291095 SNPs), this coefficient evaluation stage can be completed in roughly 1 day. Our method allows for exhaustive and rapid detection of significant SNP pair interactions without imposing significant marginal effects of the single loci involved in the pair.
Epistasis; genome-wide interaction analysis; graphical processing unit
Objective: The objective of this study was to assess the effect of treatment with interferon (IFN) β-1a, 44 µg subcutaneously (sc) three times weekly (tiw), on clinical and magnetic resonance imaging (MRI) outcomes in patients with relapsing multiple sclerosis (MS) following mitoxantrone therapy.
Methods: This was an open-label, randomized, multicentre, rater-blinded, 96-week observational study conducted in Germany. Clinically stable patients with relapsing forms of MS, who had discontinued mitoxantrone treatment 1–6 months before study entry, were randomized to IFN β-1a sc 44 µg tiw, or no treatment. The primary endpoint was time to first relapse. Secondary endpoints included the number of relapse-free patients, disease activity assessed by MRI and time to 3-month confirmed Expanded Disability Status Scale (EDSS) progression, all at week 96.
Results: A total of 30 patients were randomized (intent-to-treat population: 14 IFN β-1a, 15 untreated; one patient from the safety population discontinued the study after 25 days owing to an adverse event and without providing any postbaseline efficacy data, and was thus excluded from the intent-to-treat population). Overall, 71.4% (10/14) of patients in the IFN β-1a group remained relapse free over 96 weeks, versus 46.7% (7/15) in the untreated group (p = 0.26). IFN β-1a delayed the time to first relapse versus no treatment (p = 0.14); time to first relapse (25th percentile) was 95.4 (IFN β-1a) versus 46.0 weeks (no treatment). Confirmed EDSS progression was observed in five patients in each treatment group. Mean change in EDSS score was 0.3 in both groups (p = 0.79). Changes in the number or volume of T1 and T2 lesions at week 96 were not significantly different between treatment groups (p > 0.05). There were no new or unexpected adverse events related to IFN β-1a treatment.
Conclusions: Several endpoints appeared to show a benefit of IFN β-1a treatment, but no significant differences could be detected owing to the small sample. Therefore, these data only permit, at best, tentative conclusions about the disease course in patients with MS after de-escalation from mitoxantrone and continuation with or without IFN β-1a. Larger confirmatory studies are required.
advanced disease; de-escalation therapy; mitoxantrone; relapsing multiple sclerosis; subcutaneous interferon β-1a
An inducible release of soluble junctional adhesion molecule-A (sJAM-A) under pro-inflammatory conditions was described in cultured non-CNS endothelial cells (EC) and increased sJAM-A serum levels were found to indicate inflammation in non-CNS vascular beds. Here we studied the regulation of JAM-A expression in cultured brain EC and evaluated sJAM-A as a serum biomarker of blood-brain barrier (BBB) function.
As previously reported in non-CNS EC types, pro-inflammatory stimulation of primary or immortalized (hCMEC/D3) human brain microvascular EC (HBMEC) induced a redistribution of cell-bound JAM-A on the cell surface away from tight junctions, along with a dissociation from the cytoskeleton. This was paralleled by reduced immunocytochemical staining of occludin and zonula occludens-1 as well as by increased paracellular permeability for dextran 3000. Both a self-developed ELISA test and Western blot analysis detected a constitutive sJAM-A release by HBMEC into culture supernatants, which importantly was unaffected by pro-inflammatory or hypoxia/reoxygenation challenge. Accordingly, serum levels of sJAM-A were unaltered in 14 patients with clinically active multiple sclerosis compared to 45 stable patients and remained unchanged in 13 patients with acute ischemic non-small vessel stroke over time.
Soluble JAM-A was not suited as a biomarker of BBB breakdown in our hands. The unexpected non-inducibility of sJAM-A release at the human BBB might contribute to a particular resistance of brain EC to inflammatory stimuli, protecting the CNS compartment.
Basic disease-modifying treatment for relapsing forms of active multiple
sclerosis (MS) is now available in many countries with high prevalence rates,
for this chronic inflammatory disease of the central nervous system. Several
lines of evidence support early immunomodulatory treatment with either
recombinant interferon-beta or glatiramer acetate, and positive results from
phase III trials encourage start of treatment even in patients with clinically
isolated syndromes (CIS). However, currently available drugs for basic therapy
are only partially effective and patients may still encounter relapses or
disease progression. As treatment-refractory, clinically active MS can quickly
lead to irreversible neurological disability there is an urgent need for
effective escalating strategies. Patients with suboptimal treatment response to
basic therapy have been treated with combination therapies, cytotoxic drugs
(such as mitoxantrone and cyclophosphamide) or autologous hematopoietic stem
cell transplantation. Recently, the monoclonal antibody, natalizumab, was added
to this armamentarium. None of these strategies have been vigorously evaluated
in large randomized, controlled phase III trials with patients who failed basic
therapy. Therefore, the decision to escalate immunotherapy is still based on
limited evidence. This article will review potential candidates for intensified
immunosuppression and call for innovative study designs to better evaluate
escalating immunotherapy in MS.
immunotherapy; natalizumab; interferon-beta; glatiramer acetate; multiple sclerosis; clinically isolated syndromes
Mitochondrial DNA (mtDNA) polymorphism is a possible factor contributing to the maternal parent-of-origin effect in multiple sclerosis (MS) susceptibility.
Methods and Findings
In order to investigate the role of mtDNA variations in MS, we investigated six European MS case-control cohorts comprising >5,000 individuals. Three well matched cohorts were genotyped with seven common, potentially functional mtDNA single nucleotide polymorphisms (SNPs). A SNP, nt13708 G/A, was significantly associated with MS susceptibility in all three cohorts. The nt13708A allele was associated with an increased risk of MS (OR = 1.71, 95% CI 1.28–2.26, P = 0.0002). Subsequent sequencing of the mtDNA of 50 individuals revealed that the nt13708 itself, rather than SNPs linked to it, was responsible for the association. However, the association of nt13708 G/A with MS was not significant in MS cohorts which were not well case-control matched, indicating that the significance of association was affected by the population structure of controls.
Taken together, our finding identified the nt13708A variant as a susceptibility allele to MS, which could contribute to defining the role of the mitochondrial genome in MS pathogenesis.
The presence of an oligodendroglial component within a glioblastoma multiforme (GBM) is considered a prognostically favorable factor, but the clinical outcome of patients with glioblastoma multiforme with oligodendroglial component (GBMO) after combined post-operative radiotherapy and chemotherapy has rarely been reported.
We analyzed overall and progression-free survival in a group of ten consecutive patients initially diagnosed with GBMO between 1996 and 2004 (4.2% of all GBM patients). Median (range) age was 54 (34–73) years, 90% were resected and median radiotherapy dose was 54 (45–60.6) Gy. 80% of patients received post-operative chemotherapy with nimustine (ACNU) and VM26 (teniposide) for a median of 3.5 (1–6) cycles, the remainder were treated with post-operative radiotherapy alone. All specimens were reviewed by an experienced neuropathologist.
Neuropathological re-evaluation revealed GBM with an oligodendroglial component of 30% or less in five cases, predominant oligoastrocytic tumors with focal areas of GBM in four patients and WHO grade III oligoastrocytoma with questionable transition to GBM in one patient. Four of ten patients were alive at at 40, 41, 41 and 82 months. The median overall survival (Kaplan-Meier) was 26 months, the 2-year survival rate was 60% (progression-free survival: 9.8 months and 40%, respectively).
In conclusion, patients with GBMO treated with post-operative radiotherapy and chemotherapy with ACNU/VM26 had a better prognosis than reported for GBM in modern chemoradiation series.
In Helicobacter pylori gastritis, neutrophil activation and migration, which play central roles in the pathogenesis of the disease, are regulated by the neutrophil attractant chemokines interleukin 8 (IL-8) and Groα, whose secretion is induced by H. pylori. However, the modulation of the corresponding chemokine receptors CXCR1 and CXCR2 on human neutrophils under the influence of H. pylori has not been investigated. Incubation of neutrophils with cag+ and cag deletion H. pylori strains resulted in a complete downregulation of the CXCR1 and the CXCR2 receptors after 0.5 h, as tested by fluorescence-activated cell sorter analysis, independent of the cag status. Downregulation of CXCR1 and CXCR2 seems to occur via receptor internalization and rapid degradation, as shown by confocal microscopy and immunoblotting. Neither the proinflammatory cytokines IL-8 and tumor necrosis factor alpha produced by the neutrophils themselves nor H. pylori lipopolysaccharide, which are the known regulators of these two chemokine receptors, was responsible for the downregulation. Reverse transcription-PCR analysis showed that CXCR1 and CXCR2 mRNAs of neutrophils were reduced at a later time than the CXCR1 and CXCR2 proteins. Moreover, cag+ H. pylori strains induced significantly stronger downregulation of CXCR1 and CXCR2 mRNAs than the cag deletion mutant. Therefore, receptor protein and mRNA downregulation seem to be mediated by two independent mechanisms. Data obtained by immunohistochemistry suggested that downmodulation of CXCR1 and CXCR2 on neutrophils may also occur in vivo in the human stomach during H. pylori infection. Downregulation of CXCR1 and CXCR2 expression on neutrophils in H. pylori infection by H. pylori itself may represent a new mechanism of modulating neutrophil migration and activation in the gastric mucosa.
The envelope protein from multiple sclerosis (MS) associated retroviral element (MSRV), a member of the Human Endogenous Retroviral family ‘W’ (HERV-W), induces dysimmunity and inflammation.
The objective of this study was to confirm and specify the association between HERV-W/MSRV envelope (Env) expression and MS.
103 MS, 199 healthy controls (HC) and controls with other neurological diseases (28), chronic infections (30) or autoimmunity (30) were analysed with an immunoassay detecting Env in serum. Env RNA or DNA copy numbers in peripheral blood mononuclear cells (PBMC) were determined by a quantitative polymerase chain reaction (PCR). Env was detected by immunohistology in the brains of patients with MS with three specific monoclonals.
Env antigen was detected in a serum of 73% of patients with MS with similar prevalence in all clinical forms, and not in chronic infection, systemic lupus, most other neurological diseases and healthy donors (p<0.01). Cases with chronic inflammatory demyelinating polyneuropathy (5/8) and rare HC (4/103) were positive. RNA expression in PBMC and DNA copy numbers were significantly elevated in patients with MS versus HC (p<0.001). In patients with MS, DNA copy numbers were significantly increased in chronic progressive MS (secondary progressive MS vs relapsing–remitting MS (RRMS) p<0.001; primary progressive MS vs RRMS –<0.02). Env protein was evidenced in macrophages within MS brain lesions with particular concentrations around vascular elements.
The association between MS disease and the MSRV-type HERV-W element now appears quite strong, as evidenced ex-vivo from serum and PBMC with post-mortem confirmation in brain lesions. Chronic progressive MS, RRMS and clinically isolated syndrome show different ELISA (Enzyme-Linked Immunosorbent Assay) and/or PCR profiles suggestive of an increase with disease evolution, and amplicon sequencing confirms the association with particular HERV-W elements.
multiple sclerosis; endogenous retrovirus; HERV-W; MSRV; TLR4; syncytin; biomarker