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Several lines of evidence are indicative of a role for immune activation in the pathophysiology of schizophrenia. Nevertheless, studies using positron emission tomography (PET) and radioligands for the translocator protein (TSPO), a marker for glial activation, have yielded inconsistent results. Whereas early studies using a radioligand with low signal-to-noise in small samples showed increases in patients, more recent studies with improved methodology have shown no differences or trend-level decreases. Importantly, all patients investigated thus far have been on antipsychotic medication, and as these compounds may dampen immune cell activity, this factor limits the conclusions that can be drawn. Here, we examined 16 drug-naive, first-episode psychosis patients and 16 healthy controls using PET and the TSPO radioligand [C-11]PBR28. Gray matter (GM) volume of distribution (V-T) derived from a two-tissue compartmental analysis with arterial input function was the main outcome measure. Statistical analyses were performed controlling for both TSPO genotype, which is known to affect [C-11]PBR28 binding, and gender. There was a significant reduction of [C-11]PBR28 V-T in patients compared with healthy controls in GM as well as in secondary regions of interest. No correlation was observed between GM V-T and clinical or cognitive measures after correction for multiple comparisons. The observed decrease in TSPO binding suggests reduced numbers or altered function of immune cells in brain in early-stage schizophrenia.

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 - resident immune cells. Thus, while MS is most likely initially triggered by perturbation of peripheral immune responses the functional responses of microglia and other brain cells are also altered and may have a role in targeting an autoimmune process to the central nervous system.One Sentence Summary:We report a detailed genetic and genomic map of multiple sclerosis, and describe the role of putatively affected genes in the peripheral immune system and brain resident microglia.

Multiple sclerosis (MS) is primarily an autoimmune disease of the central nervous system, but also encompasses prominent neurodegenerative aspects. A significant proportion of MS patients will develop neurological disability over time and up until recently treatment options have been limited. However, MS treatment is now at a stage of rapid progress, with several new drugs that have reached the market or will be launched in the near future. This provides new opportunities for individualized treatment, but also creates new challenges regarding monitoring of disease activity, long-term safety issues and efficacy, not least in patients with progressive disease.

The complement system is activated in a wide spectrum of CNS diseases and is suggested to play a role in degenerative phenomena such as elimination of synaptic terminals. Still, little is known of mechanisms regulating complement activation in the CNS. Loss of synaptic terminals in the spinal cord after an experimental nerve injury is increased in the inbred DA strain compared with the PVG strain and is associated with expression of the upstream complement components C1q and C3, in the absence of membrane attack complex activation and neutrophil infiltration. To further dissect pathways regulating complement expression, we performed genome-wide expression profiling and linkage analysis in a large F2(DA × PVG) intercross, which identified quantitative trait loci regulating expression of C1qa, C1qb, C3, and C9. Unlike C1qa, C1qb, and C9, which all displayed distinct coregulation with different cis-regulated C-type lectins, C3 was regulated in a coexpression network immediately downstream of butyrylcholinesterase. Butyrylcholinesterase hydrolyses acetylcholine, which exerts immunoregulatory effects partly through TNF-α pathways. Accordingly, increased C3, but not C1q, expression was demonstrated in rat and mouse glia following TNF-α stimulation, which was abrogated in a dose-dependent manner by acetylcholine. These findings demonstrate new pathways regulating CNS complement expression using unbiased mapping in an experimental in vivo system. A direct link between cholinergic activity and complement activation is supported by in vitro experiments. The identification of distinct pathways subjected to regulation by naturally occurring genetic variability is of relevance for the understanding of disease mechanisms in neurologic conditions characterized by neuronal injury and complement activation.

Pain is a serious consequence of spinal cord injury (SCI). Our aim was to investigate the temporal aspects of different types of pain following traumatic SCI and to determine possible predictors of neuropathic pain. Prospective data on 90 patients were collected at 1, 6, and 12 months after traumatic SCI. The patients completed questionnaires on pain severity, descriptors, and impact and underwent clinical examination with bedside sensory testing. Eighty-eight patients completed the 12-month follow-up. Approximately 80% of patients reported any type of pain at all 3 time points. Neuropathic pain related to SCI increased over time, and musculoskeletal pain decreased slightly, with both being present in 59% of patients at 12 months; other neuropathic pain not related to SCI and visceral pain were present in 1 to 3%. At-level neuropathic pain present at 1 month resolved in 45% and below-level pain resolved in 33%. Early (1 month) sensory hypersensitivity (particularly cold-evoked dysesthesia) was a predictor for the development of below-level, but not at-level, SCI pain at 12 months. In conclusion, the present study demonstrates phenotypical differences between at-level and below-level SCI pain, which is important for future studies aiming to uncover underlying pain mechanisms. Perspective The finding that early sensory hypersensitivity predicts later onset of below-level central neuropathic pain may help to identify patients at risk of developing neuropathic pain conditions after traumatic spinal cord injury. Information about onset of pain may help to identify different phenotypes in neuropathic pain conditions.

We describe a woman with both central and peripheral nervous system symptoms consistent with Morvan’s syndrome who was successfully treated with immunosuppression including rituximab and the new antiepileptic drug lacosamide against peripheral nerve hyperexcitability. Despite being over 8 months in hospital and 4 months in an intensive care unit she recovered fully. It is also the first case where cerebrospinal fluid neurofilament-light (NfL) levels were followed during the disease course. The clinical course resembled that of anti-NMDA receptor encephalitis, where patients often recover surprisingly well despite severe symptoms and an extensive time in intensive care. A possible explanation is the comparatively low levels of NfL, indicating disease processes that are not characterised by extensive neuroaxonal degeneration.

Butyrylcholinesterase (BuChE) activity is associated with activated astrocytes in Alzheimer's disease brain. The BuChE-K variant exhibits 30%-60% reduced acetylcholine (ACh) hydrolyzing capacity. Considering the increasing evidence of an immune-regulatory role of ACh, we investigated if genetic heterogeneity in BuChE affects cerebrospinal fluid (CSF) biomarkers of inflammation and cholinoceptive glial function. Alzheimer's disease patients (n = 179) were BCHE-K-genotyped. Proteomic and enzymatic analyses were performed on CSF and/or plasma. BuChE genotype was linked with differential CSF levels of glial fibrillary acidic protein, S100B, interleukin-1β, and tumor necrosis factor (TNF)-α. BCHE-K noncarriers displayed 100%-150% higher glial fibrillary acidic protein and 64%-110% higher S100B than BCHE-K carriers, who, in contrast, had 40%-80% higher interleukin-1β and 21%-27% higher TNF-α compared with noncarriers. A high level of CSF BuChE enzymatic phenotype also significantly correlated with higher CSF levels of astroglial markers and several factors of the innate complement system, but lower levels of proinflammatory cytokines. These individuals also displayed beneficial paraclinical and clinical findings, such as high cerebral glucose utilization, low β-amyloid load, and less severe progression of clinical symptoms. In vitro analysis on human astrocytes confirmed the involvement of a regulated BuChE status in the astroglial responses to TNF-α and ACh. Histochemical analysis in a rat model of nerve injury-induced neuroinflammation, showed focal assembly of astroglial cells in proximity of BuChE-immunolabeled sites. In conclusion, these results suggest that BuChE enzymatic activity plays an important role in regulating intrinsic inflammation and activity of cholinoceptive glial cells and that this might be of clinical relevance. The dissociation between astroglial markers and inflammatory cytokines indicates that a proper activation and maintenance of astroglial function is a beneficial response, rather than a disease-driving mechanism. Further studies are needed to explore the therapeutic potential of manipulating BuChE activity or astroglial functional status.

Increasing evidence suggests that genetic background affects outcome of traumatic brain injuries (TBI). Still, there is limited detailed knowledge on what pathways/processes are affected by genetic heterogeneity. The inbred rat strains DA and PVG differ in neuronal survival following TBI. We here carried out global expressional profiling to identify differentially regulated pathways governing the response to an experimental controlled brain contusion injury. One of the most differentially regulated molecular networks concerned immune cell trafficking. Subsequent characterization of the involved cells using flow cytometry demonstrated greater infiltration of neutrophils and monocytes, as well as a higher degree of microglia activation in DA compared to PVG rats. In addition, DA rats displayed a higher number of NK cells and a higher ratio of CD161bright compared to CD161dim NK cells. Local expression of complement pathway molecules such as C1 and C3 was higher in DA and both the key complement component C3 and membrane-attack complex (MAC) could be demonstrated on axons and nerve cells. A stronger activation of the complement system in DA was associated with higher cerebrospinal fluid levels of neurofilament-light, a biomarker for nerve/axonal injury. In summary, we demonstrate substantial differences between DA and PVG rats in activation of inflammatory pathways; in particular, immune cell influx and complement activation associated with neuronal/axonal injury after TBI. These findings suggest genetic influences acting on inflammatory activation to be of importance in TBI and motivate further efforts using experimental forward genetics to identify genes/pathways that affect outcome.

Background: It is currently unknown whether early immunomodulatory treatment in relapsing-remitting MS (RRMS) can delay the transition to secondary progression (SP). less thanbrgreater than less thanbrgreater thanObjective: To compare the time interval from onset to SP in patients with RRMS between a contemporary cohort, treated with first generation disease modifying drugs (DMDs), and a historical control cohort. less thanbrgreater than less thanbrgreater thanMethods: We included a cohort of contemporary RRMS patients treated with DMDs, obtained from the Swedish National MS Registry (disease onset between 1995-2004, n = 730) and a historical population-based incidence cohort (onset 1950-64, n = 186). We retrospectively analyzed the difference in time to SP, termed the "period effect" within a 12-year survival analysis, using Kaplan-Meier and Cox regression analysis. less thanbrgreater than less thanbrgreater thanResults: We found that the "period" affected the entire severity spectrum. After adjusting for onset features, which were weaker in the contemporary material, as well as the therapy initiation time, the DMD-treated patients still exhibited a longer time to SP than the controls (hazard ratios: men, 0.32; women, 0.53). less thanbrgreater than less thanbrgreater thanConclusion: Our results showed there was a longer time to SP in the contemporary subjects given DMD. Our analyses suggested that this effect was not solely driven by the inclusion of benign cases, and it was at least partly due to the long-term immunomodulating therapy given. Funding Agencies|Swedish||Gothenburg Multiple Sclerosis Societies||Bayer Schering Pharma||Biogen Idec||Novartis||Sanofi-Aventis||BiogenIdec||Merck-Serono||Bayer-Schering||Teva||Swedish Research Council||Gothenburg Societies of the Neurologically Disabled

Antigen presentation by the MHC-II to CD4+ T cells is important in adaptive immune responses. The class II transactivator (CIITA in human and C2TA in mouse) is the master regulator of MHC-II gene expression. It coordinates the transcription factors necessary for the transcription of MHC-II molecules. In humans, genetic variations in CIITA have been associated with differential expression of MHC-II and susceptibility to autoimmune diseases. Here we made use of a C2ta congenic mouse strain (expressing MHC-II haplotype H-2q ) to investigate the effect of the natural genetic polymorphisms in type I promoter of C2ta on MHC-II expression and function. We demonstrate that an allelic variant in the type I promoter of C2ta resulted in an increased expression of MHC-II on macrophages (72-151% higher mean florescence intensity) and conventional dendritic cells (13-65% higher mean florescence intensity) in both spleen and peripheral blood. The increase in MHC-II expression resulted in an increase in antigen presentation to T cells in vitro and increased T-cell activation. The differential MHC-II expression in B6Q.C2ta, however, did not alter the disease development in models of rheumatoid arthritis (collagen-induced arthritis and human glucose-6-phosphate-isomerase325-339 -peptide-induced arthritis), or multiple sclerosis (MOG1-125 protein-induced and MOG79-96 peptide-induced experimental autoimmune encephalomyelitis). This is the first study to address the role of an allelic variant in type I promoter of C2ta in MHC-II expression and autoimmune diseases; and shows that C2ta polymorphisms regulate MHC-II expression and T-cell responses but do not necessarily have a strong impact on autoimmune diseases.

International audience; Using the ImmunoChip custom genotyping array, we analyzed 14,498 subjects with multiple sclerosis and 24,091 healthy controls for 161,311 autosomal variants and identified 135 potentially associated regions (P < 1.0 × 10(-4)). In a replication phase, we combined these data with previous genome-wide association study (GWAS) data from an independent 14,802 subjects with multiple sclerosis and 26,703 healthy controls. In these 80,094 individuals of European ancestry, we identified 48 new susceptibility variants (P < 5.0 × 10(-8)), 3 of which we found after conditioning on previously identified variants. Thus, there are now 110 established multiple sclerosis risk variants at 103 discrete loci outside of the major histocompatibility complex. With high-resolution Bayesian fine mapping, we identified five regions where one variant accounted for more than 50% of the posterior probability of association. This study enhances the catalog of multiple sclerosis risk variants and illustrates the value of fine mapping in the resolution of GWAS signals.

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 enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis.

Multiple sclerosis (MS) is a neuroinflammatory condition with a prominent progressive neurodegenerative facet that typically affects young- or middle-aged adults. Although physical disabilities have been in the foreground by being easier to assess, there is an increasing interest in mental disabilities and psychiatric co-morbidities, which have a disproportionally high impact on important outcome measures such as quality of life and occupational disability. In particular, cognitive impairment, depression and mental fatigue, which mutually interact with each other, seem to be of importance in this context. In recent decades, major efforts have been invested in developing more effective disease modulatory treatments. This has resulted in novel therapeutic options and awareness of the importance of early intervention. In comparison, good quality and adequately powered studies on symptomatic treatments of fatigue and psychiatric co-morbidities in MS are rare, and awareness of treatment options is much lower. We here review the existing evidence base for symptomatic treatment of fatigue and depression in MS patients. With regard to fatigue, off-label prescription of alertness improving drugs is common, in spite of all but absent evidence of efficacy. In contrast, a number of smaller studies suggest that physical exercise and fatigue management courses may have some clinical benefit. Very few studies have addressed the efficacy of antidepressants and non-pharmaceutical interventions specifically in MS patients. Therefore, treatment guidelines largely rely on data from non-MS populations. In the future, there is a strong motive to direct additional resources to the study of these important aspects of MS.

Cerebrospinal fluid (CSF) biomarkers can reflect different aspects of the pathophysiology of relapsing-remitting multiple sclerosis (RRMS). Understanding the impact of different disease modifying therapies on the CSF biomarker profile may increase their implementation in clinical practice and their appropriateness for monitoring treatment efficacy. This study investigated the influence of first-line (interferon beta) and second-line (natalizumab) therapies on seven CSF biomarkers in RRMS and their correlation with clinical and radiological outcomes. We included 59 RRMS patients and 39 healthy controls. The concentrations of C-X-C motif chemokine 13 (CXCL13), C-C motif chemokine ligand 2 (CCL2), chitinase-3-like protein 1 (CHI3L1), glial fibrillary acidic protein, neurofilament light protein (NFL), and neurogranin were determined by ELISA, and chitotriosidase (CHIT1) was analyzed by spectrofluorometry. RRMS patients had higher levels of NFL, CXCL13, CHI3L1, and CHIT1 than controls (p

Cigarette smoking is a risk factor for multiple sclerosis (MS), and the risk is further multiplied for HLA-DRB1*15(+) smokers. To define the smoke-induced immune responses in the lung we performed bronchoscopy with bronchoalveolar lavage (BAL) on smokers and non-smokers, both MS-patients and healthy volunteers. In the BAL, non-smokers with MS showed an increased preformed CD40L expression in CD4(+) T-cells while smokers displayed an increase in proliferating (Ki-67(+)) T-cells. In addition, our results confirm that smoking induces an increase of alveolar macrophages in BAL, and further defined a significant attenuation of this response in carriers of the HLA-DRB1*15 allele, in both MS patients and healthy controls. This first systematic investigation of the immune response in the lungs of smokers and non-smokers diagnosed with MS, thus suggests an MS-associated lung T-cell phenotype, involvement of a specific T-cell response to smoke, and a genetic regulation of the macrophage response.

Cognitive impairment in multiple sclerosis (MS) is common and has severe implications. Natalizumab (NZ) has documented effects on relapse rate and radiological disease activity in relapsing-remitting MS (RRMS) but studies regarding its specific effects on cognitive functioning are few. Previous studies have reported improvement, however, often lacking relevant control groups. The objective of the present study was to evaluate the cognitive effects of NZ treatment, compared to patients on stable first-line treatment and healthy control subjects.MS patients starting NZ (MS-NZ), MS controls with stable interferon beta therapy (MS-C) and healthy control subjects (HC) were evaluated twice with one year interval, using a cognitive test battery covering six cognitive domains. The effects of NZ on levels of self-reported depression, fatigue, daytime sleepiness and perceived health were also examined.MS patients (MS-NZ and MS-C) had significantly lower baseline cognitive performance compared to HC (global score, p=0.002), but there were no significant differences between MS-NZ and MS-C. At follow-up, both MS-NZ and MS-C had improved significantly in four and five cognitive domains, respectively, and in global score (p=0.013 and p0.001, respectively). HC improved significantly in three cognitive domains but not in global score. A regression analysis including baseline cognitive z-score and z-score change showed that participants with lower baseline scores had a significantly greater improvement, compared to those with better initial performance (p=0.021). There were no significant changes in depression, fatigue, daytime sleepiness or perceived health in MS-NZ or MS-C.Initiation of NZ therapy did not result in true cognitive improvement over one year. Presumably, the increased test performance in both MS groups was artificial and due to retest effects that were stronger in patients with lower baseline performance. Adequate control groups are essential when evaluating cognitive functioning in intervention trials among RRMS patients.

Background: The disease-modifying therapies (DMTs) in relapsing-remitting multiple sclerosis (RRMS) vary in their mode of action and when therapies are changed, the consequences on inflammatory and degenerative processes are largely unknown. Objective: We investigated the effect of switching from other DMTs to fingolimod on cerebrospinal fluid (CSF) biomarkers. Methods: 43 RRMS patients were followed up after 4–12 months of fingolimod treatment. Concentrations of C-X-C motif chemokine 13 (CXCL13), chemokine (C-C motif) ligand 2 (CCL2), chitinase-3-like protein 1 (CHI3L1), glial fibrillary acidic protein (GFAP), neurofilament light protein (NFL), and neurogranin (NGRN) were analyzed by enzyme-linked immunosorbent assay (ELISA), while chitotriosidase (CHIT1) was analyzed by spectrofluorometry. Results: The levels of NFL, CXCL13, and CHI3L1 decreased ( p Conclusion: We found reduced inflammatory activity (CXCL13, CHI3L1, and CHIT1) and reduced axonal damage (NFL) in patients switching from first-line DMTs to fingolimod. Biomarker levels in patients switching from natalizumab indicate similar effects on inflammatory and degenerative processes. The CSF biomarkers provide an additional measure of treatment efficacy.

Objective: To investigate the safety and efficacy of rituximab in multiple sclerosis (MS). Methods: In this retrospective uncontrolled observational multicenter study, off-label rituximab-treated patients with MS were identified through the Swedish MS register. Outcome data were collected from the MS register and medical charts. Adverse events (AEs) grades 2-5 according to the Common Terminology Criteria for Adverse Events were recorded. Results: A total of 822 rituximab-treated patients with MS were identified: 557 relapsing-remitting MS (RRMS), 198 secondary progressive MS (SPMS), and 67 primary progressive MS (PPMS). At baseline, 26.2% had contrast-enhancing lesions (CELs). Patients were treated with 500 or 1,000 mg rituximab IV every 6-12 months, during a mean 21.8 (SD 14.3) months. During treatment, the annualized relapse rates were 0.044 (RRMS), 0.038 (SPMS), and 0.015 (PPMS), and 4.6% of patients displayed CELs. Median Expanded Disability Status Scale remained unchanged in RRMS (p = 0.42) and increased by 0.5 and 1.0 in SPMS and PPMS, respectively (p = 0.10 and 0.25). Infusion-related AEs occurred during 7.8% of infusions and most were mild. A total of 89 AEs grades >= 2 (of which 76 infections) were recorded in 72 patients. No case of progressive multifocal leukoencephalopathy was detected. Conclusions: This is the largest cohort of patients with MS treated with rituximab reported so far. The safety, clinical, and MRI findings in this heterogeneous real-world cohort treated with different doses of rituximab were similar to those reported in previous randomized controlled trials on B-cell depletion therapy in MS. Classification of evidence: This study provides Class IV evidence that for patients with MS, rituximab is safe and effective.

Objectives To investigate disease history before A(H1N1)pdm09 vaccination as a risk factor for narcolepsy. Methods Case-control study in Sweden. Cases included persons referred for a Multiple Sleep Latency Test between 2009 and 2010, identified through diagnostic sleep centres and confirmed through independent review of medical charts. Controls, selected from the total population register, were matched to cases on age, gender, MSLT-referral date and county of residence. Disease history (prescriptions and diagnoses) and vaccination history was collected through telephone interviews and population-based healthcare registers. Conditional logistic regression was used to investigate disease history before A(H1N1)pdm09 vaccination as a risk-factor for narcolepsy. Results In total, 72 narcolepsy cases and 251 controls were included (range 3–69 years mean19-years). Risk of narcolepsy was increased in individuals with a disease history of nervous system disorders (OR range = 3.6–8.8) and mental and behavioural disorders (OR = 3.8, 95% CI 1.6–8.8) before referral. In a second analysis of vaccinated individuals only, nearly all initial associations were no longer statistically significant and effect sizes were smaller (OR range = 1.3–2.6). A significant effect for antibiotics (OR = 0.4, 95% CI 0.2–0.8) and a marginally significant effect for nervous system disorders was observed. In a third case-only analysis, comparing cases referred before vaccination to those referred after; prescriptions for nervous system disorders (OR = 26.0 95% CI 4.0–170.2) and ADHD (OR = 35.3 95% CI 3.4–369.9) were statistically significant during the vaccination period, suggesting initial associations were due to confounding by indication. Conclusion The findings of this study do not support disease history before A(H1N1)pdm09 vaccination as a risk factor for narcolepsy.

Multiple sclerosis (MS) is the most common nontraumatic cause of neurological deficits among young adults in the Western World. MS likely results from an organ-specific inflammatory attack of autoimmune nature against components of the central nervous system (CNS), with ensuing neurological deficits, and with time, development into a progressive disease course. More than 100 genetic variants connected to immune function predispose for the disease, as well as lifestyle/environmental factors. HLA class II genes provide the strongest impact, controlling CD4 + T cells, though, in addition there are associations to class I genes as well with a potential role of CD8 + T cells. Pathogenesis involves focal invasion of T cells into the CNS that upon recognition of so far undefined antigens are reactivated and secrete proinflammatory cytokines and chemokines recruiting additional cell types. These include macrophages that are important effector cells damaging not only myelin, but also nerve fibers. Current knowledge of key mechanisms in neuroinflammation has led to a series of modestly or highly effective treatments, though some of them, due to their broad action in the immune system, can lead to serious adverse events. Further detailed knowledge on MS-specific mechanisms is needed to develop more selective treatments with improved effect/risk profiles.

Background Chronic pain of neuropathic nature after spinal cord injury (SCI) is common and its underlying mechanisms are poorly understood. Genes, as well as sex, have been implicated, but not thoroughly investigated in experimental genetic models for complex traits. We have previously found that inbred Dark-Agouti (DA) rats develop more severe SCI pain-like behaviour than a major histocompatibility complex-congenic Piebald Virol Glaxo (PVG)-RT1av1 strain in a model of photochemically induced SCI. Methods In this study, a genome-wide linkage study in an F2 cross between the susceptible DA and resistant PVG-RT1av1 strains was performed in order to explore the influence of genes and sex for SCI pain. Results A consistent finding was that female rats in parental, F1 and F2 generations displayed increased pain sensitivity at testing before injury and also developed mechanical hypersensitivity more rapidly and to a greater extent than male rats. In addition, we could identify three quantitative trait loci (QTLs) associated with pain-like behaviour: a sex-specific QTL on chromosome 2, one on chromosome 15 and on chromosome 6. Animals carrying DA alleles at each of these loci were more susceptible to development of mechanical hypersensitivity compared with rats with PVG alleles. Conclusion This is the first whole genome QTL mapping of neuropathic pain-like behaviour in a model of SCI. The results provide strong support for a significant genetic and sex component in development of pain after SCI and provide the basis for further genetic dissection and positional cloning of the underlying genes.

Nitric oxide is a key mediator of post-traumatic inflammation in the brain. We examined the expressions of iNOS, nNOS, and eNOS in inbred DA and PVGa rat strains where DA is susceptible to autoimmune neuroinflammation and PVGa-resistant.Parietal contusions using a weight drop model were produced in five rats per genotype. After 24 h, the brains were removed and analyzed using a range of immunohistochemical methods.PVGa presented significantly increased iNOS expression in infiltrating inflammatory cells in the perilesional area compared to DA (p0.05). The amount of w3/13-positive infiltrating inflammatory cells did not differ between strains. eNOS and nNOS expression did not differ between strains. iNOS-positive cells coexpressed neuronal (NeuN), macrophage (ED-1), and leucocyte (w3/13) markers. MnSOD was significantly increased in PVGa (p0.05). 3-Nitrotyrosine, a measure of peroxynitrite levels, and fluoro-jade stained neuronal degeneration, did not differ between strains.Two inbred rat strains with genetically determined differences in susceptibility to develop autoimmune disease displayed different levels of the inflammatory and anti-inflammatory mediators iNOS and MnSOD, indicating genetic regulation. Interestingly, the increased levels of iNOS did not lead to elevated expression of the neuronal cell-death marker fluoro-jade. The increased iNOS expression was correlated with increased expression of superoxide scavenger MnSOD. Excessive peroxynitrite formation was probably prevented by limitation of available superoxide. Subsequently, the higher expression of potentially deleterious iNOS in PVGa did not result in increased neuronal death.

A large number of molecular pathways have been implicated in the degeneration of axotomized motoneurons. We previously have demonstrated substantial differences in the survival rate of axotomized motoneurons across different rat strains. Identification of genetic differences underlying such naturally occurring strain differences is a powerful approach, also known as forward genetics, to gain knowledge of mechanisms relevant for complex diseases, like injury-induced neurodegeneration. Overlapping congenic rat strains were used to fine map a gene region on rat chromosome eight previously shown to regulate motoneuron survival after ventral root avulsion. The smallest genetic fragment, R5, contains 35 genes and displays a highly significant regulatory effect on motoneuron survival. Furthermore, expression profiling in a F2(DAxPVG) intercross demonstrates one single cis-regulated gene within the R5 fragment; Gsta4, encoding glutathione S-transferase alpha-4. Confirmation with real-time PCR shows higher Gsta4 expression in PVG compared with DA both in naïve animals and at several time points after injury. Immunolabeling with a custom made rat Gsta4 antibody demonstrates a neuronal staining pattern, with a strong cytoplasmic labeling of motoneurons. These results demonstrate and map naturally occurring genetic differences in the expression of Gsta4 is associated both with a highly significant increase in the survival of axotomized motoneurons and with a trans-regulation of several molecular pathways involved in neurodegenerative processes. This adds to a large body of evidence implicating lipid peroxidation as an important pathway for neurodegeneration.

Genetic regulation of autoimmune neuroinflammation is a well known phenomenon, but genetic influences on inflammation following traumatic nerve injuries have received little attention. In this study we examined the inflammatory response in a rat traumatic brain injury (TBI) model, with a particular focus on major histocompatibility class II (MHC II) presentation, in two inbred rat strains that have been extensively characterized in experimental autoimmune encephalomyelitis (EAE); DA and PVG. In addition, MHC and Vra4 congenic strains on these backgrounds were studied to give information on MHC and non-MHC gene contribution. Thus, allelic differences in Vra4, harboring the Ciita gene, was found to regulate expression of the invariant chain at the mRNA level, with a much smaller effect exerted by the MHC locus itself. Notably, however, at the protein level the MHC congenic PVG-RT1(av1) strain displayed much stronger MHCII(+) presentation, as shown both by immunolabeling and flow cytometry, than the PVG strain, dwarfing the effect of Ciita. The PVG-RT1(av1) strain had significantly more T-cell influx than both DA and PVG, suggesting regulation both by MHC and non-MHC genes. Finally, in terms of outcome, the EAE susceptible DA strain displayed a significantly smaller resulting lesion volume than the resistant PVG-RT1(av1) strain. These results provide additional support for a role of adaptive immune response after neurotrauma and demonstrate that outcome is significantly affected by host genetic factors.

A marked increase in concomitant autoimmune diseases has previously been noted in patients with myasthenia gravis (MG). We show that these diseases occur both before and after the onset of MG and that the process is not influenced by thymectomy. IgA deficiency (IgAD), which is strongly associated with the same HLA haplotype as early onset MG, has recently been suggested to be an autoimmune disease. However, there was no increase in the prevalence of IgAD in a large cohort of Swedish MG patients.

Background: A post marketing surveillance study was conducted to evaluate safety and efficacy of natalizumab in Swedish multiple sclerosis (MS) patients since its introduction in August 2006 until March 2010. Methods: Patients were registered in the web-based Swedish MS-registry at 40 locations and evaluated every 6 months. Adverse events and clinical outcomes were recorded. Results: One thousand one hundred and fifty-two patients were included (71.4% female) and 149 patients stopped treatment; the main reason was planned pregnancy. Anti-natalizumab antibodies were found in 4.5% (52 patients) of which 1.6% displayed persistent antibodies. Serious adverse events were rare, but included three cases with progressive multifocal leukoencephalopathy (PML). There were seven fatal cases, probably unrelated to the natalizumab treatment. For relapsing–remitting MS patients ( n = 901), mean Expanded Disability Status Scale (EDSS, −10.7%), Multiple Sclerosis Severity Scale (MSSS, −20.4%), Multiple Sclerosis Impact Scale (MSIS-29, physical −9.9%, psychological −13.3%) and Symbol Digit Modalities Test (SDMT, +10.7%) all showed significant improvements during 24 months of treatment with natalizumab. The Swedish web-based MS quality registry proved to function as a platform for post-marketing MS drug surveillance, providing long-term data regarding drug effects and adverse events beyond clinical trials. Conclusions: Our results indicate that natalizumab is generally well tolerated and has sustained efficacy for patients with active MS, though the risk of PML is still an important concern.

Proper transcriptional control of pro- and anti-inflammatory responses of the immune system is important for a fine-tuned balance between protection and tolerance. Emerging evidence suggests a key role for epigenetic regulation in governing the Th cell differentiation, where effector cytokines direct the overall immune response. In this study, we describe a method to pinpoint the location of isolated human CD4+ T cells on any T cell effector axis based on specific CpG methylation of cytokine and transcription factor loci. We apply the method on CD4+ cells obtained from rheumatoid arthritis and multiple sclerosis patients and show that synovial fluid infiltrating CD4+ T cells are committed toward both Th1 and regulatory T cell phenotype, whereas the Th2 response is suppressed. Furthermore, we show that the IL-17A gene is regulated by promoter methylation and that Th17 commitment is not a common feature in the inflamed joints of rheumatoid arthritis patients. We conclude that the method described in this paper allows for accurate profiling of Th lineage commitment in ex vivo-isolated CD4+ T cells.

Authors Disclaimer: http://medpub-poster.merckgroup.com/ABN2018DISC_CLARIFY.pdfBackgroundRelapsing multiple sclerosis (RMS) negatively affects health-related quality of life (HRQoL).ObjectiveAn open-label, single-arm, exploratory Phase IV study in centres in Europe and Australia will assess HRQoL in RMS patients receiving CT 3.5 mg/kg (CT3.5).MethodsEligible patients will receive CT 3.5 (cumulative) over 2 years. HRQoL (Multiple Sclerosis Quality of Life-54 [MSQoL-54]) and other patient-reported outcomes (Fatigue Severity Scale; Hospital Anxiety and Depression Scale; Treatment Satisfaction Questionnaire for Medication v1.4) will be assessed at baseline, and at 6, 12, 24 months.Other outcomes include AEs, MRI measures (T1 Gd+ lesions, T2 lesions, brain atrophy), number of relapses, and disability/functioning measures (EDSS; 9-Hole Peg Test; Timed 25-Foot Walk and Brief International Cognitive Assessment for Multiple Sclerosis). The sample size estimation is based on the power to detect a mean difference of 5 points in MSQoL-54 composite score at 24 months vs baseline.ResultsThe study aims to recruit 356 adults with RMS by 2019. Final data are anticipated in 2022.ConclusionsThis study will explore the effects of CT on HRQoL outcomes, and describe the effects of CT on treatment satisfaction and disability/functioning.Disclosure statementThe trial is sponsored by Merck KGaA, Darmstadt, Germany.

Comparative real-world effectiveness studies of initial disease-modifying treatment (DMT) choices for relapsing-remitting multiple sclerosis (RRMS) that include rituximab are lacking.To assess the effectiveness and drug discontinuation rates of rituximab among patients with newly diagnosed RRMS compared with injectable DMTs, dimethyl fumarate, fingolimod, or natalizumab.This retrospective cohort study used prospectively collected data to examine specialized care of 2 Swedish county-based community samples of patients with RRMS. Patients with RRMS who received diagnoses from January 1, 2012, to October 31, 2015, who resided in Stockholm or Västerbotten Counties were identified from a Swedish multiple sclerosis registry.All reasons for drug discontinuation of initial treatment choice (main outcome) and specific reasons for switching (secondary outcomes) were analyzed with multivariable Cox regression, including propensity scores.Among 494 patients (median [interquartile range] age, 34.4 [27.4-43.4] years; 158 men [32.0%]), 215 received an injectable DMT (43.5%); 86 (17.4%), dimethyl fumarate; 17 (3.4%), fingolimod; 50 (10.1%), natalizumab; 120 (24.3%), rituximab; and 6 (1.2%), other DMT. Regional preferences were pronounced, with 42 of 52 (81%) and 78 of 442 (18%) receiving rituximab in Västerbotten and Stockholm, respectively. The annual discontinuation rate for rituximab, injectable DMTs, dimethyl fumarate, fingolimod, and natalizumab were 0.03, 0.53, 0.32, 0.38, and 0.29, respectively. Continued disease activity was the main reason for discontinuation of injectable DMTs, dimethyl fumarate, and fingolimod; positive John Cunningham virus serology results were the main reason for discontinuation of natalizumab. Rate of clinical relapses and/or neuroradiologic disease activity were significantly lower for rituximab compared with injectable DMTs and dimethyl fumarate, with a tendency for lower relapse rates also compared with natalizumab and fingolimod. The annual discontinuation rate of initial treatment choice was significantly lower in Västerbotten compared with Stockholm (0.09 and 0.37, respectively).Rituximab was superior to all other DMT in terms of drug discontinuation and displayed better clinical efficacy compared with injectable DMTs and dimethyl fumarate with borderline significance compared with natalizumab and fingolimod. The county where rituximab constituted the main initial treatment choice displayed better outcomes in most measured variables. Collectively, our findings suggest that rituximab performs better than other commonly used DMTs in patients with newly diagnosed RRMS.

Systemic Lupus Erythematosis (SLE) is a multi-system autoimmune disease. Putative biomarkers for neuropsychiatric SLE (NPSLE) include antibodies against the DWEYS peptide, a sequence present on the extracellular portion of NR2A/B receptors. We tested for binding of antibodies to conformational state neuronal proteins, including the NMDA receptor to understand potential pathogenicity of these antibodies. Paired serum and CSF from 35 patients SLE/NPSLE were studied. No binding was observed to natively expressed NMDARs or live hippocampal neurons. A DWEYS-reactive ELISA showed by comparison to healthy controls, SLE patients (p=0.0001) and disease-controls (predominantly MS (n=36, (p=0.016)) but not antibody-controls (aquaporin-4- (n=11), LGI1- (n=13) and NMDAR- (n=10) antibody diseases, p=0.375) showed greater binding, suggesting this assay is not selective for NPSLE/SLE. Binding was unaffected by a scrambled or charge altered DWEYS peptide. However, the same samples also showed similar binding to the plate without the DWEYS peptide. Uncoated versus coated plate ELISA data showed Spearman’s correlations>0.79 across all cohorts. NPSLE does not associate with antibodies to NR1 or NR2A/B homomers/heteromers or cultured hippocampal neurons in their native, conformational state. The DWEYS assay is not a reliable way to test for NPSLE, and literature discrepancies may result from the propensity of SLE patients to bind ELISA plates. We would not recommend further use or exploration of the DWEYS assay in SLE.

Local CNS inflammation takes place in many neurological disorders and is important for autoimmune neuroinflammation. Microglial activation is strain-dependent in rats and differential MHC class II expression is influenced by variations in the Mhc2ta gene. Despite sharing Mhc2ta and MHC class II alleles, BN and LEW.1N rats differ in MHC class II expression after ventral root avulsion (VRA). We studied MHC class II expression and glial activation markers in BN rats after VRA. Our results demonstrate that MHC class II expression originates from a subpopulation of IBA1(+), ED1(-), and ED2(-) microglia. We subsequently performed a genome-wide linkage scan in an F2(BNxLEW.1N) population, to investigate gene regions regulating this inflammatory response. Alongside MHC class II, we studied the expression of MHC class I, co-stimulatory molecules, complement components, microglial markers and Il1b. MHC class II and other transcripts were commonly regulated by gene regions on chromosomes 1 and 7. Furthermore, a common region on chromosome 10 regulated expression of complement and co-stimulatory molecules, while a region on chromosome 11 regulated MHC class I. We also detected epistatic interactions in the regulation of the inflammatory process. These results reveal the complex regulation of CNS inflammation by several gene regions, which may have relevance for disease.

Numerous CNS diseases of primarily non-inflammatory origin, such as idiopathic neurodegenerative diseases, contain elements of inflammation, with T cell infiltration, MHC class II expression and neuron/axon damage. Gene mapping in human clinical materials have in most cases failed to unravel discrete genes, since most genes instrumental in non-Mendelian forms of these complex diseases are likely to modestly affect risk, be evolutionary conserved in the population and vary between individuals. We here describe the exploration of susceptibility to neurodegeneration and inflammatory glial activation in response to mechanical nerve injury using experimental genetic models. The response to ventral root avulsion, which is a simple and reproducible model of nerve injury-induced neurodegeneration and inflammation, was examined in a panel of inbred rat strains. A whole genome scan subsequently performed in a F2(DAxPVG) intercross identified quantitative trait loci (QTLs) regulating different features of the nerve injury response. Fine mapping in an advanced intercross line revealed polymorphisms in the Mhc2ta gene as being responsible for strain differences in MHC class II expression. Furthermore, a polymorphism in the syntenic human gene, MHC2TA, was associated both with lower expression of MHC class II-associated genes and increased susceptibility to inflammatory diseases. These results provide important insights into the genetic regulation of fundamental physiological responses of the nervous system to damage and demonstrate relevance also for human diseases.

Inflammation is a common characteristic of spinal cord injury. The nature of this response, whether it is beneficial or detrimental, has been the subject of debate. It has been reported that susceptibility to autoimmunity is correlated with increased functional impairment following spinal cord injury. As the ability to mount an autoimmune response has most consistently been associated with certain haplotypes of the major histocompatibility complex (MHC), we analysed the possible effects of the MHC haplotype on functional impairment and recovery following spinal cord injury. A contusion injury was induced in experimental autoimmune encephalomyelitis-susceptible and -resistant rats [Dark Agouti, Lewis and Piebald Viral Glaxo (PVG), respectively]. We found that locomotion recovered significantly better in Dark Agouti rats compared with PVG and Lewis rats but an F2 intercross (PVG x PVG-RT1 av1 ) excluded the possibility that this difference was MHC haplotype-dependent. Thus, we conclude that recovery following spinal cord injury is subject to considerable genetic heterogeneity that is not coupled to the MHC haplotype region. Continued research of genetic variants regulating recovery following spinal cord injury is warranted.

Background Activation of the complement system has been implicated in both acute and chronic states of neurodegeneration. However, a detailed understanding of this complex network of interacting components is still lacking. Methods Large-scale global expression profiling in a rat F2(DAxPVG) intercross identified a strong cis-regulatory influence on the local expression of complement receptor 2 (Cr2) in the spinal cord after ventral root avulsion (VRA). Expression of Cr2 in the spinal cord was studied in a separate cohort of DA and PVG rats at different time-points after VRA, and also following sciatic nerve transection (SNT) in the same strains. Consequently, Cr2−/− mice and Wt controls were used to further explore the role of Cr2 in the spinal cord following SNT. The in vivo experiments were complemented by astrocyte and microglia cell cultures. Results Expression of Cr2 in naïve spinal cord was low but strongly up regulated at 5–7 days after both VRA and SNT. Levels of Cr2 expression, as well as astrocyte activation, was higher in PVG rats than DA rats following both VRA and SNT. Subsequent in vitro studies proposed astrocytes as the main source of Cr2 expression. A functional role for Cr2 is suggested by the finding that transgenic mice lacking Cr2 displayed increased loss of synaptic nerve terminals following nerve injury. We also detected increased levels of soluble CR2 (sCR2) in the cerebrospinal fluid of rats following VRA. Conclusions These results demonstrate that local expression of Cr2 in the central nervous system is part of the axotomy reaction and is suggested to modulate subsequent complement mediated effects. Electronic supplementary material The online version of this article (doi:10.1186/s12974-015-0413-6) contains supplementary material, which is available to authorized users.

Many JC virus antibody-positive relapsing-remitting multiple sclerosis (RRMS) patients who are stable on natalizumab switch to other therapies to avoid progressive multifocal leukoencephalopathy.We compared outcomes for all RRMS patients switching from natalizumab due to JC virus antibody positivity at 3 Swedish multiple sclerosis centers with different preferential use of rituximab and fingolimod (Stockholm, n = 156, fingolimod 51%; Gothenburg, n = 64, fingolimod 88%; Umeå, n = 36, fingolimod 19%), yielding a total cohort of N = 256 (fingolimod 55%).Within 1.5 years of cessation of natalizumab, 1.8% (rituximab) and 17.6% (fingolimod) of patients experienced a clinical relapse (hazard ratio for rituximab = 0.10, 95% confidence interval [CI] = 0.02-0.43). The hazard ratio (favoring rituximab) for adverse events (5.3% vs 21.1%) and treatment discontinuation (1.8% vs 28.2%) were 0.25 (95% CI = 0.10-0.59) and 0.07 (95% CI = 0.02-0.30), respectively. Furthermore, contrast-enhancing lesions were found in 1.4% (rituximab) versus 24.2% (fingolimod) of magnetic resonance imaging examinations (odds ratio = 0.05, 95% CI = 0.00-0.22). Differences remained when adjusting for possible confounders (age, sex, disability status, time on natalizumab, washout time, follow-up time, and study center).Our findings suggest an improved effectiveness and tolerability of rituximab compared with fingolimod in stable RRMS patients who switch from natalizumab due to JC virus antibody positivity. Although residual confounding factors cannot be ruled out, the shared reason for switching from natalizumab and the preferential use of either rituximab or fingolimod in 2 of the centers mitigates these concerns. Ann Neurol 2016;79:950-958.

Since first described less than ten years ago, anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is now recognized as one of the most common causes of autoimmune encephalitis. The disorder is more common in women (80%), where it is frequently associated with an underlying ovarian teratoma. Most patients with anti-NMDAR encephalitis develop a multi-stage illness that progresses from initially psychiatric symptoms to subsequent mnemonic disturbances, seizures, dyskinesias, catatonia and even coma. Since the neurological and psychiatric symptoms can be highly variable upon presentation, the disease is probably under-diagnosed. Outcome is likely to be improved with prompt diagnosis and early treatment. Here we describe a hospital-based case series of six patients that illustrate the wide clinical spectrum of the condition. The series also includes one severely ill patient with treatment-refractory disease who was hospitalized with invasive ventilation for seven months, and eventually responded to a combination of rituximab, cyclophosphamide and bortezomib.

Amyotrophic lateral sclerosis (ALS) is the most common motor neuron disease. It is typically fatal within 2–5 years of symptom onset. The incidence of ALS is largely uniform across most parts of the world, but an increasing ALS incidence during the last decades has been suggested. Although recent genetic studies have substantially improved our understanding of the causes of ALS, especially familial ALS, an important role of non-genetic factors in ALS is recognized and needs further study. In this review, we briefly discuss several major genetic contributors to ALS identified to date, followed by a more focused discussion on the most commonly examined non-genetic risk factors for ALS. We first review factors related to lifestyle choices, including smoking, intake of antioxidants, physical fitness, body mass index, and physical exercise, followed by factors related to occupational and environmental exposures, including electromagnetic fields, metals, pesticides, β-methylamino-L-alanine, and viral infection. Potential links between ALS and other medical conditions, including head trauma, metabolic diseases, cancer, and inflammatory diseases, are also discussed. Finally, we outline several future directions aiming to more efficiently examine the role of non-genetic risk factors in ALS.

Chitinase 3-like 1 (CHI3L1) has been proposed as a biomarker associated with the conversion to clinically definite multiple sclerosis in patients with clinically isolated syndromes, based on the finding of increased cerebrospinal fluid CHI3L1 levels in clinically isolated syndrome patients who later converted to multiple sclerosis compared to those who remained as clinically isolated syndrome. Here, we aimed to validate CHI3L1 as a prognostic biomarker in a large cohort of patients with clinically isolated syndrome. This is a longitudinal cohort study of clinically isolated syndrome patients with clinical, magnetic resonance imaging, and cerebrospinal fluid data prospectively acquired. A total of 813 cerebrospinal fluid samples from patients with clinically isolated syndrome were recruited from 15 European multiple sclerosis centres. Cerebrospinal fluid CHI3L1 levels were measured by enzyme-linked immunosorbent assay. Multivariable Cox regression models were used to investigate the association between cerebrospinal fluid CHI3L1 levels and time to conversion to multiple sclerosis and time to reach Expanded Disability Status Scale 3.0. CHI3L1 levels were higher in patients who converted to clinically definite multiple sclerosis compared to patients who continued as clinically isolated syndrome (P = 8.1 × 10−11). In the Cox regression analysis, CHI3L1 levels were a risk factor for conversion to multiple sclerosis (hazard ratio = 1.7; P = 1.1 × 10−5 using Poser criteria; hazard ratio = 1.6; P = 3.7 × 10−6 for McDonald criteria) independent of other covariates such as brain magnetic resonance imaging abnormalities and presence of cerebrospinal fluid oligoclonal bands, and were the only significant independent risk factor associated with the development of disability (hazard ratio = 3.8; P = 2.5 × 10−8). High CHI3L1 levels were associated with shorter time to multiple sclerosis (P = 3.2 × 10−9 using Poser criteria; P = 5.6 × 10−11 for McDonald criteria) and more rapid development of disability (P = 1.8 × 10−10). These findings validate cerebrospinal fluid CHI3L1 as a biomarker associated with the conversion to multiple sclerosis and development of disability and reinforce the prognostic role of CHI3L1 in patients with clinically isolated syndrome. We propose that determining cerebrospinal fluid chitinase 3-like 1 levels at the time of a clinically isolated syndrome event will help identify those patients with worse disease prognosis., E.C. is supported by a contract from the “Fondo de Investigación Sanitaria” – FIS [contract number FI 09/00705], Ministry of Science and Innovation, Spain. R.N. is supported by the “Programa Juan de la Cierva” from the Ministry of Science and Innovation, Spain. Local CSF biobanking of the multiple sclerosis group in Prague was supported by Research Project Charles University in Prague (PRVOUK P34/LF3).

Dysregulation of the complement system is evident in many CNS diseases but mechanisms regulating complement activation in the CNS remain unclear. In a recent large rat genomewide expression profiling and linkage analysis we found co-regulation of complement C3 immediately downstream of butyrylcholinesterase (BuChE), an enzyme hydrolyzing acetylcholine (ACh), a classical neurotransmitter with immunoregulatory effects. We here determined levels of neurofilament-light (NFL), a marker for ongoing nerve injury, C3 and activity of the two main ACh hydrolyzing enzymes, acetylcholinesterase (AChE) and BuChE, in cerebrospinal fluid (CSF) from patients with MS (n = 48) and non-inflammatory controls (n = 18). C3 levels were elevated in MS patients compared to controls and correlated both to disability and NFL. C3 levels were not induced by relapses, but were increased in patients with >= 9 cerebral lesions on magnetic resonance imaging and in patients with progressive disease. BuChE activity did not differ at the group level, but was correlated to both C3 and NFL levels in individual samples. In conclusion, we show that CSF C3 correlates both to a marker for ongoing nerve injury and degree of disease disability. Moreover, our results also suggest a potential link between intrathecal cholinergic activity and complement activation. These results motivate further efforts directed at elucidating the regulation and effector functions of the complement system in MS, and its relation to cholinergic tone.

Traumatic brain injury (TBI) is a common cause of death and disability, worldwide. Early determination of injury severity is essential to improve care. Neurofilament light (NF-L) has been introduced as a marker of neuroaxonal injury in neuroinflammatory/-degenerative diseases. In this study we determined the predictive power of serum (s-) and cerebrospinal fluid (CSF-) NF-L levels towards outcome, and explored their potential correlation to diffuse axonal injury (DAI). A total of 182 patients suffering from TBI admitted to the neurointensive care unit at a level 1 trauma center were included. S-NF-L levels were acquired, together with S100B and neuron-specific enolase (NSE). CSF-NF-L was measured in a subcohort (n = 84) with ventriculostomies. Clinical and neuro-radiological parameters, including computerized tomography (CT) and magnetic resonance imaging, were included in the analyses. Outcome was assessed 6 to 12 months after injury using the Glasgow Outcome Score (1-5). In univariate proportional odds analyses mean s-NF-L, -S100B and -NSE levels presented a pseudo-R2 Nagelkerke of 0.062, 0.214 and 0.074 in correlation to outcome, respectively. In a multivariate analysis, in addition to a model including core parameters (pseudo-R2 0.33 towards outcome; Age, Glasgow Coma Scale, pupil response, Stockholm CT score, abbreviated injury severity score, S100B), S-NF-L yielded an extra 0.023 pseudo-R2 and a significantly better model (p = 0.006) No correlation between DAI or CT assessed-intracranial damage and NF-L was found. Our study thus demonstrates that S-NF-L correlates to TBI outcome, even if used in models with S100B, indicating an independent contribution to the prediction, perhaps by reflecting different pathophysiological processes, not possible to monitor using conventional neuroradiology. Although we did not find a predictive value of NF-L for DAI, this cannot be completely excluded. We suggest further studies, with volume quantification of axonal injury, and a prolonged sampling time, in order to better determine the connection between NF-L and DAI.

Background: Neuromyelitis optica (NMO) is an inflammatory autoimmune disorder of the central nervous system, hallmarked by pathogenic anti-aquaporin 4 antibodies. NMO prognosis is worse compared with multiple sclerosis. Objective: The European Group for Blood and Marrow Transplantation (EBMT) Autoimmune Diseases Working Party (ADWP) conducted a retrospective survey to analyze disease outcome following autologous stem cell transplantation (ASCT). Methods: This retrospective multicenter study assessed the efficacy and safety of ASCT in 16 patients suffering from refractory NMO reported to the EBMT registry between 2001 and 2011. Results: Fifteen patients were successfully mobilized with cyclophosphamide (Cy) and G-CSF, one with G-CSF alone. All patients received an unmanipulated autologous peripheral blood stem cell graft, after conditioning with BEAM plus anti-thymocyte globulin (ATG, n = 9 patients), thiotepa-Cy (n = 3) or Cy (200 mg/kg) plus ATG (n = 4). After a median follow-up of 47 months, three of 16 cases were progression and treatment free, while in the remaining 13 patients further treatments were administered for disability progression or relapse after ASCT. Altogether, relapse-free survival at three and five years was 31% and 10%, respectively, while progression-free survival remained 48% at three and five years. Conclusions: In these NMO patients, highly resistant to conventional treatment, ASCT allows for temporary control of the disease, despite a tendency to progress or relapse in the long term. Neuromyelitis optica (NMO) is an inflammatory autoimmune disorder of the central nervous system, hallmarked by pathogenic anti-aquaporin 4 antibodies. NMO prognosis is worse compared with multiple sclerosis. OBJECTIVE: The European Group for Blood and Marrow Transplantation (EBMT) Autoimmune Diseases Working Party (ADWP) conducted a retrospective survey to analyze disease outcome following autologous stem cell transplantation (ASCT). METHODS: This retrospective multicenter study assessed the efficacy and safety of ASCT in 16 patients suffering from refractory NMO reported to the EBMT registry between 2001 and 2011. RESULTS: Fifteen patients were successfully mobilized with cyclophosphamide (Cy) and G-CSF, one with G-CSF alone. All patients received an unmanipulated autologous peripheral blood stem cell graft, after conditioning with BEAM plus anti-thymocyte globulin (ATG, n = 9 patients), thiotepa-Cy (n = 3) or Cy (200 mg/kg) plus ATG (n = 4). After a median follow-up of 47 months, three of 16 cases were progression and treatment free, while in the remaining 13 patients further treatments were administered for disability progression or relapse after ASCT. Altogether, relapse-free survival at three and five years was 31% and 10%, respectively, while progression-free survival remained 48% at three and five years. CONCLUSIONS: In these NMO patients, highly resistant to conventional treatment, ASCT allows for temporary control of the disease, despite a tendency to progress or relapse in the long term.

Background and objective: We explored which clinical and biochemical variables predict conversion from clinically isolated syndrome (CIS) to clinically definite multiple sclerosis (CDMS) in a large international cohort. Methods: Thirty-three centres provided serum samples from 1047 CIS cases with at least two years’ follow-up. Age, sex, clinical presentation, T2-hyperintense lesions, cerebrospinal fluid (CSF) oligoclonal bands (OCBs), CSF IgG index, CSF cell count, serum 25-hydroxyvitamin D3 (25-OH-D), cotinine and IgG titres against Epstein-Barr nuclear antigen 1 (EBNA-1) and cytomegalovirus were tested for association with risk of CDMS. Results: At median follow-up of 4.31 years, 623 CIS cases converted to CDMS. Predictors of conversion in multivariable analyses were OCB (HR = 2.18, 95% CI = 1.71–2.77, p < 0.001), number of T2 lesions (two to nine lesions vs 0/1 lesions: HR = 1.97, 95% CI = 1.52–2.55, p < 0.001; >9 lesions vs 0/1 lesions: HR = 2.74, 95% CI = 2.04–3.68, p < 0.001) and age at CIS (HR per year inversely increase = 0.98, 95% CI = 0.98–0.99, p < 0.001). Lower 25-OH-D levels were associated with CDMS in univariable analysis, but this was attenuated in the multivariable model. OCB positivity was associated with higher EBNA-1 IgG titres. Conclusions: We validated MRI lesion load, OCB and age at CIS as the strongest independent predictors of conversion to CDMS in this multicentre setting. A role for vitamin D is suggested but requires further investigation.

To investigate the genetics of late-onset myasthenia gravis (LOMG), we conducted a genome-wide association study imputation of >6 million single nucleotide polymorphisms (SNPs) in 532 LOMG cases (anti-acetylcholine receptor [AChR] antibody positive; onset age ≥50 years) and 2,128 controls matched for sex and population substructure. The data confirm reported TNFRSF11A associations (rs4574025, P = 3.9 × 10−7, odds ratio [OR] 1.42) and identify a novel candidate gene, ZBTB10, achieving genome-wide significance (rs6998967, P = 8.9 × 10−10, OR 0.53). Several other SNPs showed suggestive significance including rs2476601 (P = 6.5 × 10−6, OR 1.62) encoding the PTPN22 R620W variant noted in early-onset myasthenia gravis (EOMG) and other autoimmune diseases. In contrast, EOMG-associated SNPs in TNIP1 showed no association in LOMG, nor did other loci suggested for EOMG. Many SNPs within the major histocompatibility complex (MHC) region showed strong associations in LOMG, but with smaller effect sizes than in EOMG (highest OR ∼2 versus ∼6 in EOMG). Moreover, the strongest associations were in opposite directions from EOMG, including an OR of 0.54 for DQA1*05:01 in LOMG (P = 5.9 × 10−12) versus 2.82 in EOMG (P = 3.86 × 10−45). Association and conditioning studies for the MHC region showed three distinct and largely independent association peaks for LOMG corresponding to (a) MHC class II (highest attenuation when conditioning on DQA1), (b) HLA-A and (c) MHC class III SNPs. Conditioning studies of human leukocyte antigen (HLA) amino acid residues also suggest potential functional correlates. Together, these findings emphasize the value of subgrouping myasthenia gravis patients for clinical and basic investigations and imply distinct predisposing mechanisms in LOMG.

Axonal damage, a core feature of neurological diseases, induces a retrograde reaction in neurons and surrounding glia. We determined transcriptional profiles of this reaction using Affymetrix oligonucleotide arrays. Gene expression was examined in spinal cord tissue prior to injury and following ventral root avulsion in two inbred rat strains, where the degree of neurodegeneration differs. Stringent statistical analysis revealed 278 regulated genes, whereof 245 were regulated by the injury and 68 differed between strains. Principal component analysis disclosed a common injury response pattern significantly modified by genetic background. Notably, inflammatory genes comprised the largest group of genes induced by injury and these transcripts prevailed in the strain most susceptible to neurodegeneration. In addition, levels of the strain regulated genes C1qb and Timp1 correlated with degree of neurodegeneration in a cohort of genetically heterogeneous animals. These results suggest a link between the inflammatory response elicited by nerve injury and subsequent neurodegeneration.

Chemokines are important for the recruitment of immune cells into sites of inflammation. To better understand their functional roles during inflammation we have here studied the in vivo expression of receptors for the chemokines CCL3/CCL5/CCL7 (MIP‐1α/RANTES/MCP‐3) and CX(3)CL1 (fractalkine), CCR1 and CX(3)CR1, respectively, in rat myelin oligodendrocyte glycoprotein‐induced experimental autoimmune encephalomyelitis. Combined in situ hybridization and immunohistochemistry demonstrated intensely upregulated CCR1 mRN A expression in early, actively demyelinating plaques, whereas CX(3)CR1 displayed a more generalized expression pattern. CX(3)CR1 mRNA expressing cells were identified as microglia on the basis of their cellular morphology and positive GSA/B4 lectin staining. In contrast, CCR1 mRNA was preferentially expressed by ED1(+)GSA/B4(+) macrophages. The notion of differential chemokine receptor expression in microglia and monocyte‐derived macrophages was corroborated at the protein level by extraction and flow cytometric sorting of cells infiltrating the spinal cord using gating for the surface markers CD45, ED‐2 and CD11b. These observations suggest a differential receptor expression between microglia and monocyte‐derived macrophages and that mainly the latter cell type is responsible for active demyelination. This has great relevance for the possibility of therapeutic intervention in demyelinating diseases such as multiple sclerosis, for example by targeting signaling events leading to monocyte recruitment.

In the animal model for multiple sclerosis (MS), experimental autoimmune encephalitis (EAE), genetic loci correlating with incidence or severity of disease are located both within and outside of the major histocompatibility complex (MHC). Whereas polymorphisms within MHC class I and II molecules are likely to be a major determinant of MHC gene influence in rat EAE, it is still unclear how non-MHC gene regions influence disease. Genetic control of inflammation can hypothetically be either general or specific for a particular target tissue. For the latter, gene regulation of pathomechanisms in the CNS could affect reactivity of microglia or astrocytes, local cytokine/chemokine production, or even neuronal vulnerability. We have obtained strong support for this notion by observations of rat strain-dependent variation in the inflammatory response after ventral root avulsion, a model in which mainly non-antigen-specific elements of the immune system promote inflammation. A comparison of strains with similar MHC haplotypes on different backgrounds and strains with different MHC haplotypes on the same background, respectively, demonstrates that the inflammatory phenotype is regulated mainly by non-MHC genes. Interestingly, different features of the inflammatory response, such as induction of MHC class II expression, glial activation, cytokine expression, and neuronal vulnerability, varied between rat strains and were largely independent of each other. The genetic control of several basic features of inflammation in the CNS is of great relevance not only for MS/EAE, but also for several other neurological conditions with inflammatory components such as cerebrovascular and neurogenerative dieases and trauma.

Many CNS diseases of primarily noninflammatory origin, such as chronic neurodegenerative diseases, stroke and trauma, display inflammatory features. Conversely, damage to nerve cells and axons has emerged as a clinically important parameter of autoimmune neuroinflammatory conditions such as multiple sclerosis. Experimental data are conflicting as to whether neuroinflammatory reactions should be regarded as detrimental, or as an apt response serving to minimize nervous tissue damage. Despite this, modulation of inflammation is one of the most dynamic areas in the search for new therapeutic targets for a spectrum of CNS diseases. Recent developments in the field have unravelled an intricate regulation of neuroinflammation and disclosed several avenues that, with further exploration, may result in new ways of treating common and disabling CNS diseases.