Multiple sclerosis: infectious hypothesis

Adoptive T-cell therapy targeting Epstein-Barr virus as a treatment for multiple sclerosis

Emergence of a definitive link between Epstein-Barr virus (EBV) and multiple sclerosis has provided an impetus to develop immune-based therapies to target EBV-infected B cells. Initial studies with autologous EBV-specific T-cell therapy demonstrated that this therapy is safe with minimal side effects and more importantly multiple patients showed both symptomatic and objective neurological improvements including improved quality of life, reduction of fatigue and reduced intrathecal IgG production. These observations have been successfully extended to an 'off-the-shelf' allogeneic EBV-specific T-cell therapy manufactured using peripheral blood lymphocytes of healthy seropositive individuals. This adoptive immunotherapy has also been shown to be safe with encouraging clinical responses. Allogeneic EBV T-cell therapy overcomes some of the limitations of autologous therapy and can be rapidly delivered to patients with improved therapeutic potential.

Clinical effectiveness and cost-effectiveness of beta-interferon and glatiramer acetate for treating multiple sclerosis: systematic review and economic evaluation

BACKGROUND

At the time of publication of the most recent National Institute for Health and Care Excellence (NICE) guidance [technology appraisal (TA) 32] in 2002 on beta-interferon (IFN-β) and glatiramer acetate (GA) for multiple sclerosis, there was insufficient evidence of their clinical effectiveness and cost-effectiveness.

OBJECTIVES

To undertake (1) systematic reviews of the clinical effectiveness and cost-effectiveness of IFN-β and GA in relapsing-remitting multiple sclerosis (RRMS), secondary progressive multiple sclerosis (SPMS) and clinically isolated syndrome (CIS) compared with best supportive care (BSC) and each other, investigating annualised relapse rate (ARR) and time to disability progression confirmed at 3 months and 6 months and (2) cost-effectiveness assessments of disease-modifying therapies (DMTs) for CIS and RRMS compared with BSC and each other.

REVIEW METHODS

Searches were undertaken in January and February 2016 in databases including The Cochrane Library, MEDLINE and the Science Citation Index. We limited some database searches to specific start dates based on previous, relevant systematic reviews. Two reviewers screened titles and abstracts with recourse to a third when needed. The Cochrane tool and the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) and Philips checklists were used for appraisal. Narrative synthesis and, when possible, random-effects meta-analysis and network meta-analysis (NMA) were performed. Cost-effectiveness analysis used published literature, findings from the Department of Health's risk-sharing scheme (RSS) and expert opinion. A de novo economic model was built for CIS. The base case used updated RSS data, a NHS and Personal Social Services perspective, a 50-year time horizon, 2014/15 prices and a discount rate of 3.5%. Outcomes are reported as incremental cost-effectiveness ratios (ICERs). We undertook probabilistic sensitivity analysis.

RESULTS

In total, 6420 publications were identified, of which 63 relating to 35 randomised controlled trials (RCTs) were included. In total, 86% had a high risk of bias. There was very little difference between drugs in reducing moderate or severe relapse rates in RRMS. All were beneficial compared with BSC, giving a pooled rate ratio of 0.65 [95% confidence interval (CI) 0.56 to 0.76] for ARR and a hazard ratio of 0.70 (95% CI, 0.55 to 0.87) for time to disability progression confirmed at 3 months. NMA suggested that 20 mg of GA given subcutaneously had the highest probability of being the best at reducing ARR. Three separate cost-effectiveness searches identified > 2500 publications, with 26 included studies informing the narrative synthesis and model inputs. In the base case using a modified RSS the mean incremental cost was £31,900 for pooled DMTs compared with BSC and the mean incremental quality-adjusted life-years (QALYs) were 0.943, giving an ICER of £33,800 per QALY gained for people with RRMS. In probabilistic sensitivity analysis the ICER was £34,000 per QALY gained. In sensitivity analysis, using the assessment group inputs gave an ICER of £12,800 per QALY gained for pooled DMTs compared with BSC. Pegylated IFN-β-1 (125 µg) was the most cost-effective option of the individual DMTs compared with BSC (ICER £7000 per QALY gained); GA (20 mg) was the most cost-effective treatment for CIS (ICER £16,500 per QALY gained).

LIMITATIONS

Although we built a de novo model for CIS that incorporated evidence from our systematic review of clinical effectiveness, our findings relied on a population diagnosed with CIS before implementation of the revised 2010 McDonald criteria.

CONCLUSIONS

DMTs were clinically effective for RRMS and CIS but cost-effective only for CIS. Both RCT evidence and RSS data are at high risk of bias. Research priorities include comparative studies with longer follow-up and systematic review and meta-synthesis of qualitative studies.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016043278.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Relationship between Neutrophil-to-Lymphocyte Ratio and Stress in Multiple Sclerosis Patients

INTRODUCTION

Multiple Sclerosis (MS), a disease of autoimmunity and inflammation, is characterized by deterioration of the myelin sheath that protects the nerve fibers. The high levels of neutrophils in serum may be related to the chronic inflammation and caused by other triggers such as infections that have been associated with relapses in MS.

AIM

To investigate the value of Neutrophil/Lymphocyte Ratio (NLR) as a possible marker and relationship with Depression, Anxiety and Stress (DAS) score in MS patients.

MATERIALS AND METHODS

A total of 60 MS patients and 60 age and sex matched healthy controls were recruited for the present study. We measured DAS score, NLR, calcium, phosphate, magnesium, chloride, alkaline phosphatase, albumin in serum levels in MS patients and in healthy controls.

RESULTS

The mean age was not significantly different in both case and control groups. The case and control groups were similar in terms of sex; however, the majority of the MS group was female. The NLR values of MS patients were significantly higher than those of the healthy controls (p=<0.001). The NLR values were also significantly (p<0.001) correlated with stress score.

CONCLUSION

NLR could be considered as a quick, cheap, easily measurable and inflammatory marker for assessment of inflammation in MS patients. The role of NLR in MS must be explored further.

Multiple sclerosis in women having children by multiple partners. A population-based study in Denmark

We investigated whether having children with multiple men is a risk factor for being diagnosed with multiple sclerosis (MS). We studied a cohort of 151 328 women, of whom 64 704 had different men fathering their children and 86 624 the same partner for all births. Women were included if they had a second or higher parity child between 1973 and 1996. The follow-up for MS ended in 1997. There were a total of 213 cases of MS diagnosed during the study period. We analysed data through Poisson regression models. Women having children with different men were not at higher risk of being diagnosed with MS, with the possible exception of a short period after having a baby with a new partner. Women having children with more than one man may have a higher risk of a pregnancy accelerating the diagnosis of MS but are probably not at an overall higher risk of MS.

Chlamydia pneumoniae infection and the risk of multiple sclerosis: a meta-analysis

We conducted a meta-analysis of studies comparing the presence of Chlamydia pneumoniae (Cpn) between multiple sclerosis (MS) patients and other neurological diseases patients or healthy controls. We identified 26 studies with 1332 MS patients and 1464 controls. Using random-effects methods, MS patients were found more likely to have detectable levels of Cpn DNA (OR = 3.216; 95% CI: 1.204, 8.585) in their cerebrospinal fluid, and intrathecally synthesized immunoglobulins (OR = 3.842; 95% CI: 1.317, 11.212), compared to other patients with neurological diseases. There is no evidence for increased levels of serum immunoglobulins (OR = 1.068; 95% CI: 0.745, 1.530), even though this result is confounded by the presence of studies using normal subjects as controls. Similarly, there is no evidence for association of immunoglobulins against Cpn in the cerebrospinal fluid (OR = 3.815; 95% CI: 0.715, 20.369). Up to 59.7% of the between-studies variability could be explained by the inappropriate matching of cases and controls for gender. In random-effects meta-regressions, adjusting for the confounding effect of gender differences results in stronger and statistically significant associations of MS with detectable levels of Cpn DNA, intrathecally synthesized immunoglobulins and immunoglobulins in the cerebrospinal fluid. Even though the presence of Cpn is clearly more likely in MS patients, these findings are insufficient to establish an etiologic relation.

The environmental risk factors in multiple sclerosis susceptibility: A case-control study

Background:

Multiple sclerosis (MS) is a demyelinating and degenerating disease which involves central nervous system. Environmental risk factors have a key role in MS susceptibility. Here we aim to investigate different risk factors effect on MS susceptibility in a large population of MS patients in Isfahan, Iran.

Materials and Methods:

This study is a cross-sectional hospital-based study, which was conducted on a large group of MS patients registered in Kashani hospital and a control group from normal healthy population. Demographic data, age at onset of the disease, history of viral infections, vaccination, history of trauma to head, recent stressful events, alimentation, familial history, method of delivery (caesarean section, normal vaginal delivery), disability score and history of smoking were gathered using a designed questionnaire.

Results:

Totally 536 MS patient with the mean age of 34.37 ± 9.22 and 399 individuals from healthy population with the mean age of 32.53 ± 9.91 were recruited. Significant difference in history of measles infection (control = 15.5%, case = 22.4%, P = 0.009), consumption of dairy products (case = 56.6%, control = 67.5%, P = 0.01) and major stressful life events (case = 62.2%, control = 52.7%, P < 0.05) between these two groups were demonstrated.

Conclusion:

A significant relation between stress, history of infection and milk consumption was reached that highlights the importance of environmental risk factors in MS pathogenesis.

JC Virus Replication at the First Symptoms of Multiple Sclerosis: A Case Report

Multiple sclerosis (MS) is an autoimmune, demyelinating disorder of unknown etiology, in which viruses have been suggested as etiological/triggering agents. The attention to the association between viruses and MS has been rekindled by the development of progressive multifocal leukoencephalopathy in natalizumab-treated MS patients. Here we report the case of a woman with JC virus (JCV) replication in the cerebrospinal fluid, blood and urine collected at the first symptoms of MS and during several follow-up visits. This observation shows that JCV can be associated with MS without a relation with natalizumab treatment, although the triggering role of JCV in some cases of MS will require further studies.

Guard of delinquency? A role of microglia in inflammatory neurodegenerative diseases of the CNS

Activation of microglia and inflammation-mediated neurotoxicity are believed to play an important role in the pathogenesis of several neurodegenerative disorders, including multiple sclerosis. Studies demonstrate complex functions of activated microglia that can lead to either beneficial or detrimental outcomes, depending on the form and the timing of activation. Combined with genetic and environmental factors, overactivation and dysregulation of microglia cause progressive neurotoxic consequences which involve a vicious cycle of neuron injury and unregulated neuroinflammation. Thus, modulation of microglial activation appears to be a promising new therapeutic target. While current therapies do attempt to block activation of microglia, they indiscriminately inhibit inflammation thus also curbing beneficial effects of inflammation and delaying recovery. Multiple signaling cascades, often cross-talking, are involved in every step of microglial activation. One of the key challenges is to understand the molecular mechanisms controlling cytokine expression and phagocytic activity, as well as cell-specific consequences of dysregulated cytokine expression. Further, a better understanding of how the integration of multiple cytokine signals influences the function or activity of individual microglia remains an important research objective to identify potential therapeutic targets for clinical intervention to promote repair.

Polymorphonuclear Cell Functional Impairment in Relapsing Remitting Multiple Sclerosis Patients: Preliminary Data

Multiple Sclerosis patients run an increased risk of microbial infections, which leads to high rates of hospitalization and infection-related mortality. Although immunotherapy may increase infection risk in some cases, data as to the relationship among microbial factors, immunotherapy and alterations in the innate immunity of these patients are still scanty. On these grounds, this interdisciplinary study aims at investigating the role the functional activity of polymorphonuclear cells (PMNs) play in relapsing remitting multiple sclerosis at different stages. The in vitro ability of PMNs from patients, either untreated or treated with immunosuppressant or immunomodulatory drugs to kill Klebsiella pneumonia or Candida albicans, were investigated and compared to PMNs from healthy subjects. The release of various cytokines was also assessed, as was the production of reactive oxygen species and their ability to regulate apoptosis after microbial stimulation. Our results indicate that although patients have a normal number of PMNs, they have a statistically significant (p<0.05) reduction in intracellular killing activity. Although variations are strongly related to the therapeutic management of patients, they are independent from their disease stage. As no statistically significant differences were observed between patients and controls in cytokine release values, reactive oxygen species production or apoptosis, we came to the conclusion that other factors may be involved. Supportive validation of these results from further studies might well help in identifying a subset of patients at high risk of infection who could benefit from a closer follow-up and/or antibiotic prophylaxis.

The clinical significance of the neutrophil-to-lymphocyte ratio in multiple sclerosis

Multiple sclerosis (MS) is one of the main chronic inflammatory diseases of the central nervous system that causes functional disability in young people. The aim of this study was to investigate the neutrophil-to-lymphocyte ratio (NLR) in patients with MS and the relationship between the NLR and the severity of the disease. One hundred and two MS patients (31 patients were in relapse; 71 patients were in remission) and 56 healthy controls were included. Complete blood counts as well as demographic and clinical data from MS patients were evaluated retrospectively. The NLRs were calculated for all participants and were compared; the cut-off value was also determined for the NLR and Expanded Disability Status Scale (EDSS). MS patients had a significantly higher NLR (p < 0.001) than the control group. The NLR levels were significantly higher in patients who were in relapse than patients in remission (p = 0.039). The cut-off value for the NLR to predict an MS diagnosis and activity were determined to be 2.04 and 3.90, respectively. The NLRs were directly correlated with erythrocyte sedimentation rate levels (r = 0.795, p < 0.001). Logistic regression analysis with dichotomous EDSS score showed that a high NLR was an independent predictor of the progression of disability. The NLR may be a biomarker that has simple, quick, inexpensive and reproducible properties in MS to predict patient's prognosis.

The good and the bad of neuroinflammation in multiple sclerosis

Multiple sclerosis (MS) is the most common inflammatory, demyelinating, neurodegenerative disorder of the central nervous system (CNS). It is widely considered a T-cell mediated autoimmune disease that develops in genetically susceptible individuals, possibly under the influence of certain environmental trigger factors. The invasion of autoreactive CD4+ T-cells into the CNS is thought to be a central step that initiates the disease. Several other cell types, including CD8+ T-cells, B-cells and phagocytes appear to be involved in causing inflammation and eventually neurodegeneration. But inflammation is not entirely deleterious in MS. Evidence has accumulated in the recent years that show the importance of regulatory immune mechanisms which restrain tissue damage and initiate regeneration. More insight into the beneficial aspects of neuroinflammation might allow us to develop new treatment strategies for this enigmatic disease.

Gender differences in circulating levels of neutrophil extracellular traps in serum of multiple sclerosis patients

Neutrophil extracellular traps (NETs) trap and kill pathogens very efficiently but also activate dendritic cells and prime T cells. Previously, we demonstrated that neutrophils are primed and circulating NETs are elevated in relapsing remitting multiple sclerosis (RRMS), a T cell-mediated autoimmune disease. Here, we demonstrate gender specific differences in circulating NETs but not in neutrophil priming in RRMS patients. Although the results from our systematic and in depth characterization of these patients argue against a major role of circulating NETs in this disease, they suggest that NETs may underlie gender-specific differences in MS pathogenesis.

Diagnostic biomarkers in multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory demyelinating disease of the CNS and comprises a heterogeneous spectrum of disease subtypes. The distinctive variability of clinical presentations, histopathologic and immunologic patterns, as well as neuroradiologic phenotypes in MS poses a diagnostic challenge to the attending physician and claims a more differentiated typing of MS patients by diagnostic biomarkers in order to anticipate the expected disease course and to stratify patients for specifically tailored therapies. In this paper, the major biomarkers presently recommended in the diagnosis of MS are reviewed, including magnetic resonance imaging, the analysis of cerebrospinal fluid parameters and the diagnostic relevance of antibodies to aquaporin-4 water channels and myelin antigens.

Epstein-Barr virus stimulates torque teno virus replication: a possible relationship to multiple sclerosis

Viral infections have been implicated in the pathogenesis of multiple sclerosis. Epstein-Barr virus (EBV) has frequently been investigated as a possible candidate and torque teno virus (TTV) has also been discussed in this context. Nevertheless, mechanistic aspects remain unresolved. We report viral replication, as measured by genome amplification, as well as quantitative PCR of two TTV-HD14 isolates isolated from multiple sclerosis brain in a series of EBV-positive and -negative lymphoblastoid and Burkitt's lymphoma cell lines. Our results demonstrate the replication of both transfected TTV genomes up to day 21 post transfection in all the evaluated cell lines. Quantitative amplification indicates statistically significant enhanced TTV replication in the EBV-positive cell lines, including the EBV-converted BJAB line, in comparison to the EBV-negative Burkitt's lymphoma cell line BJAB. This suggests a helper effect of EBV infections in the replication of TTV. The present study provides information on a possible interaction of EBV and TTV in the etiology and progression of multiple sclerosis.

Neutrophils in multiple sclerosis are characterized by a primed phenotype

Neutrophils are armed with proteases with indiscriminate histotoxic potential, and to minimize tissue injury, their activation involves priming with inflammatory mediators before cells are fully activated in a second step. Here, we show that neutrophils in multiple sclerosis patients are more numerous and exhibit a primed state based on reduced apoptosis, higher expression of TLR-2, fMLP receptor, IL-8 receptor and CD43, enhanced degranulation and oxidative burst as well as higher levels of neutrophil extracellular traps in serum. The chronic inflammatory environment in multiple sclerosis probably underlies this inappropriate neutrophil priming, which may result in enhanced neutrophil activation during infection.

Factors predisposing to the development of multiple sclerosis

Multiple sclerosis (MS) is a chronic neurological disease, which is known to be more common in UK than many countries. While there are multiple genetic factors affecting risk of developing MS and disease severity within the condition, evidence on the rising worldwide prevalence and the increasing female to male preponderance has focused interest on environmental factors influencing MS risk. Data on several of these factors are reviewed, with particular focus on those such as vitamin intake, smoking and obesity, which may be influenced at a personal and population level by medical advice.

Potential triggers of MS

MS is an immune mediated disease of the central nervous system (CNS) characterized by demyelination, axonal damage and neurologic disability. The primary cause of this CNS disease remains elusive. Here we will address our current understanding of the role of viruses as potential environmental triggers for MS. Virus infections can act peripherally (outside the CNS) or within the CNS. The association of viral infections with demyelinating disease, in both animals and humans, will be discussed, as will the potential contributions of peripheral infection with Torque Teno virus, infection outside of and/or within the CNS with Epstein-Barr virus and infection within the CNS with Human Herpesvirus 6 to MS. An experimental animal model, Theiler's murine encephalomyelitis virus infection of susceptible strains of mice is an example of viral infections of the CNS as a prerequisite for demyelination. Finally, the proposition that multiple virus infections are required, which first prime the immune system and then trigger the disease, as a model where infections outside of the CNS lead to inflammatory changes within the CNS, for the development of a MS-like disease is explored.

Targeting myelin proteolipid protein to the MHC class I pathway by ubiquitination modulates the course of experimental autoimmune encephalomyelitis

Relapsing-remitting experimental autoimmune encephalomyelitis (EAE), a multiple sclerosis model, is induced in mice by injection of myelin proteolipid protein (PLP) encephalitogenic peptide, PLP139-151, in adjuvant. In this study, prior to EAE induction, mice were vaccinated with a bacterial plasmid encoding a PLP-ubiquitin fusion (pCMVUPLP). During the relapse phase of EAE, clinical signs, histopathologic changes, in vitro lymphoproliferation to PLP139-151 and interferon-gamma levels were reduced in pCMVUPLP-vaccinated mice, compared to mock-vaccinated mice (controls). Lymphocytes from pCMVUPLP-vaccinated mice produced interleukin-4, a cytokine lacking in controls. Thus, pCMVUPLP vaccination can modulate the relapse after EAE induction.

Human RNA "rumor" viruses: the search for novel human retroviruses in chronic disease

Retroviruses are an important group of pathogens that cause a variety of diseases in humans and animals. Four human retroviruses are currently known, including human immunodeficiency virus type 1, which causes AIDS, and human T-lymphotropic virus type 1, which causes cancer and inflammatory disease. For many years, there have been sporadic reports of additional human retroviral infections, particularly in cancer and other chronic diseases. Unfortunately, many of these putative viruses remain unproven and controversial, and some retrovirologists have dismissed them as merely "human rumor viruses." Work in this field was last reviewed in depth in 1984, and since then, the molecular techniques available for identifying and characterizing retroviruses have improved enormously in sensitivity. The advent of PCR in particular has dramatically enhanced our ability to detect novel viral sequences in human tissues. However, DNA amplification techniques have also increased the potential for false-positive detection due to contamination. In addition, the presence of many families of human endogenous retroviruses (HERVs) within our DNA can obstruct attempts to identify and validate novel human retroviruses. Here, we aim to bring together the data on "novel" retroviral infections in humans by critically examining the evidence for those putative viruses that have been linked with disease and the likelihood that they represent genuine human infections. We provide a background to the field and a discussion of potential confounding factors along with some technical guidelines. In addition, some of the difficulties associated with obtaining formal proof of causation for common or ubiquitous agents such as HERVs are discussed.

JC virus viremia in interferon-beta -treated and untreated Italian multiple sclerosis patients and healthy controls

Following the development of progressive multifocal leukoencephalopathy (PML) in two multiple sclerosis (MS) patients treated with natalizumab and interferon-beta (IFNbeta), a possible correlation between JC virus (JCV), the etiological agent of PML, and MS has received heightened interest. In particular, attention has focused on assessing whether IFNbeta treatment could affect the replication of JCV and thus its frequency in the peripheral blood of MS patients and whether the presence of JCV DNA in peripheral blood could be a predictive marker of the risk of developing PML. In order to answer to these questions, peripheral blood samples were collected from 59 INFbeta-treated, 39 untreated relapsing-remitting MS patients, and 98 healthy controls (HCs) and JCV DNA levels were determined and quantified by means of a real-time polymerase chain reaction (Q-PCR) assay. Overall, no differences were found in the presence or viral load of JCV DNA of MS patients and the HCs, but JCV DNA was significantly less frequent in the peripheral blood of IFNbeta-treated patients (13.6%) compared to the untreated MS patients (46.1%) and the healthy controls (28.6%). These results suggest that the presence of JCV in the blood of MS patients cannot be considered as a marker or a risk factor for PML development. In addition, they indicate that treatment with INFbeta can lead to the reduction of presence of the JCV genome in the peripheral blood of MS patients and, thus, that this drug probably does not increase the risk of PML in MS patients treated with IFNbeta.

Reactivation of JC virus and development of PML in patients with multiple sclerosis

The attention of researchers and clinicians specializing in both multiple sclerosis (MS) and JC virus (JCV), the etiologic agent of progressive multifocal leukoencephalopathy (PML), was rekindled by the development of PML in two patients with MS enrolled in a clinical trial of combination therapy with natalizumab (Tysabri) and interferon beta-1A (Avonex) in recent years. PML had not been previously reported with either MS or treatment with interferon beta alone. This occurrence of PML with alpha4beta1-integrin inhibition in MS raised a number of issues in terms both of the scientific understanding of these diseases and for the future of immunomodulatory treatment for MS. In this review, we examine the current status of knowledge of the virus, its molecular biology, life cycle, and pathogenetic mechanisms, and how this relates to the basic science and clinical perspectives of MS. A better understanding of the specific steps from JCV infection to the development of PML is key to this issue. Other critical issues for further investigation include the role of alpha4beta1-integrin inhibition by natalizumab in the re-expression of JCV from latent sites and in the inhibition of entry into the brain and peripheral sites.

Experimental Autoimmune Encephalomyelitis Mediated by CD8+ T Cells

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system that is believed to have an autoimmune origin. CD4(+) T cells have been well studied for their involvement in the pathogenesis of MS and its animal model, experimental autoimmune encephalomyelitis (EAE). CD8(+) T cells, however, have been overlooked until recently, when more attention has focused on their potential role in pathogenic mechanisms in MS. Here we summarize our work in generating a CD8(+) T cell-mediated EAE model. We discuss immune tolerance mechanisms that regulate CD8(+) T cells specific for myelin basic protein (MBP), and describe initial results regarding triggers of CD8(+) T cell-mediated disease. The availability of CD8(+) T cell-mediated EAE models will help to elucidate the pathogenic roles of CD8(+) T cells in MS, and provide tools for development of novel therapies for MS.

Regulatory T cells maintain long-term tolerance to myelin basic protein by inducing a novel, dynamic state of T cell tolerance

The pathogenesis of multiple sclerosis involves a breakdown in T cell tolerance to myelin proteins like myelin basic protein (MBP). Most MBP-specific T cells are eliminated by central tolerance in adult mice, however, the developmentally regulated expression of MBP allows MBP-specific thymocytes in young mice to escape negative selection. It is not known how these T cells that encounter MBP for the first time in the periphery are regulated. We show that naive MBP-specific T cells transferred into T cell-deficient mice induce severe autoimmunity. Regulatory T cells prevent disease, however, suppression of the newly transferred MBP-specific T cells is abrogated by activating APCs in vivo. Without APC activation, MBP-specific T cells persist in the periphery of protected mice but do not become anergic, raising the question of how long-term tolerance can be maintained if APCs presenting endogenous MBP become activated. Our results demonstrate that regulatory T cells induce naive MBP-specific T cells responding to nonactivated APCs to differentiate into a unique, tolerized state with the ability to produce IL-10 and TGF-beta1 in response to activated, but not nonactivated, APCs presenting MBP. This tolerant response depends on continuous activity of regulatory T cells because, in their absence, these uniquely tolerized MBP-specific T cells can again induce autoimmunity.

Increased prevalence of varicella zoster virus DNA in cerebrospinal fluid from patients with multiple sclerosis

In order to investigate the possible involvement of viruses in Multiple Sclerosis (MS), the study evaluated the presence of viral genomic sequences in cerebrospinal fluid (CSF), as markers of viral replication within the central nervous system (CNS). A total of 85 CSF samples were collected from 38 MS patients, 28 patients with other neurological diseases and 19 subjects without neurological diseases. Using nested-PCR, the investigation focused on the presence of human herpes virus DNA, including herpes simplex virus 1 (HSV-1) and 2 (HSV-2), the Epstein-Barr virus (EBV), varicella zoster virus (VZV), human cytomegalovirus (HCMV), human herpes virus 6 (HHV-6) and JC virus (JCV). All the CSF samples from the individuals without neurological diseases were negative for viral DNA. Genomic sequences of HSV-1, HCMV, EBV, HHV6, and JCV were found in patients with MS and other neurological diseases without significant differences between the two groups. VZV DNA was detected more frequently (P < 0.05) in the MS group (31.6%), particularly among the relapsing-remitting MS patients (43.5%), compared with patients with other neurological diseases (10.7%). In addition, the results indicated that JCV and HHV-6 were replicating actively in the CNS of a small, but significant number of patients with MS and other neurological diseases. Most importantly, the study revealed a high frequency of VZV DNA in the CSF of patients with MS, suggesting a possible role of this virus in the pathogenesis of MS.

Serum IgE reactive against small myelin protein-derived peptides is increased in multiple sclerosis patients

Though independent findings suggest roles for the allergic arm of the immune system and myelin-reactive antibodies in MS, myelin-reactive IgE has not been investigated. We have developed a radioimmunoassay that measures reactive IgE, IgG and IgA against short (5-6-mers) myelin protein-derived peptides bearing little to no sequence identity with other human proteins, and which might therefore be targets of a CNS-specific autoimmune attack. Here we show that, irrespective of clinical subtype, MS patients' sera are characterized by a higher frequency of measurable IgE against the peptides. Moreover, in controls with measurable IgE reactive against test peptides, IgG or IgA reactive with the same peptide epitopes is almost always present in vastly greater quantities, whereas in MS subjects peptide-reactive IgA or IgG is often undetectable. The sensitivity of the full assay, when considering overall positive a serum sample that has detectable autoreactive IgE without other competing Igs, is 69% (S.E.: 5%), with a specificity of 87% (S.E.: 9%). We speculate that IgE reactive against CNS target antigens may have both diagnostic and pathogenic significance, particularly if other peptide-specific, potentially blocking Igs are absent.

Sibship characteristics and risk of multiple sclerosis: a nationwide cohort study in Denmark

It has been hypothesized that age at infection with a common microbial agent may be associated with the risk of multiple sclerosis (MS). The authors addressed this hypothesis by using number of older siblings and other sibship characteristics as an approximation of age at exposure to common infections. Data on family characteristics and vital status from the Danish Civil Registration System were used to establish a cohort of all Danes whose mothers had been born in Denmark since 1935. Persons diagnosed with MS during the period 1968-1998 were identified through linkage with the Danish Multiple Sclerosis Register. The cohort of 1.9 million Danes was followed for 28.1 million person-years; during that time, 1,036 persons developed MS. Overall, there was no association between number of older siblings, number of younger siblings, total number of siblings, age distance from the nearest younger sibling, or exposure to younger siblings under 2 years of age and risk of MS later in life. There was no association of MS risk with multiple birth (vs. singleton birth) or with the age of the mother or father at birth. These results do not lend support to the hypothesis that number of older siblings or any of the other sibship characteristics studied is associated with risk of MS.

Multiple sclerosis mortality and patterns of comorbidity in the United States from 1990 to 2001

Multiple sclerosis (MS) is a neurodegenerative condition that can result in cognitive and physical disability and shortened life expectancy. However, population-based information is lacking regarding the mortality burden from MS in the United States. We investigated trends in MS mortality rates and examined important comorbidities in the United States from 1990 to 2001. MS deaths were matched by age, sex, and race/ethnicity with randomly selected deaths from other conditions for matched odds ratio comparisons. The overall age-adjusted mortality rate from MS was 1.44/100,000 population. MS mortality rates increased throughout the study period. MS mortality rates were higher in whites than in any other racial/ethnic group, followed by Blacks, Hispanics, American Indians/Alaska Natives, and Asians and Pacific Islanders. Observed mortality rates were more than 10 times lower in Asians and Pacific Islanders than in whites. The odds of pressure ulcers, urinary tract infections, and pneumonia/influenza being reported on the death certificate were higher in MS deaths than in matched controls.

No evidence for production of intrathecal immunoglobulin G against Acinetobacter or Pseudomonas in multiple sclerosis

The production of oligoclonal, polyspecific immunoglobulin G is characteristic of multiple sclerosis (MS), yet no pathogen has been identified as an infectious agent. Recent studies have proposed Acinetobactercalcoaceticus and Pseudomonas aeruginosa as candidate organisms, on the basis of a sequence homology between a bacterial enzyme and bovine myelin basic protein. To investigate this, we looked for specific, high-affinity immunoglobulin G against these pathogensin paired serum and cerebrospinal fluid from MS patients compared to other neurological diseases. We found no greater incidence of high-affinity antibodies against the organisms studied in MS vs. other neurological diseases, and so conclude that A. calcoaceticus and P. aeruginosa are unlikely to be implicated in the pathogenesis of MS.

Seasonal Variations in Exacerbations and MRI Parameters in Relapsing- Remitting Multiple Sclerosis

Environmental factors may be involved in the etiology of multiple sclerosis (MS). We investigate prevalence of exacerbations and MRI findings in a cohort of relapsing-remitting multiple sclerosis patients, for evidence of seasonal variation or cyclic trends. We find only weak evidence of seasonality in our data. Differences in reports of seasonal variation in multiple sclerosis disease activity may be due to regional climatic differences or other geographic variables that change with latitude as well as genetic predisposition.

Interferon-β in the treatment of relapsing–remitting multiple sclerosis

The role of interferon-beta as a disease-modifying drug (DMD) for the treatment of relapsing-remitting multiple sclerosis (RRMS) is now well established, and its efficacy has been demonstrated unequivocally in large-scale clinical trials. However, current evidence suggests that in order to increase the benefit of therapy, use of an effective drug and dosing regimen should be commenced early in the course of the disease, a finding that places new emphasis on the need for early diagnosis. Indeed, it is now known that MS lesions often develop at a subclinical level and that axonal damage occurs even in the very early stages of the disease. Moreover, such damage may be irreversible, and there is strong evidence to suggest that efficacy lost as a consequence of delay in the onset of treatment or the use of a suboptimal drug regimen cannot be regained. At present, the choice of interferon-beta is complicated by the availability of 3 different products, each with a different dosing regimen. Although the optimal interferon-beta dosing regimen for RRMS has been the focus of much discussion, the issues of dose, and particularly dosing frequency, have not been satisfactorily addressed in clinical trials until recently. Over the last 2 years, however, 3 comparative studies of interferon-beta products have been conducted. The results obtained from these recent trials underline the importance of both dose and dosing frequency and indicate that for improved efficacy in RRMS, interferon-beta therapy should be administered frequently at the highest tolerable, and thus most effective, dose.

Infectious agents and multiple sclerosis--are Chlamydia pneumoniae and human herpes virus 6 involved?

A good deal of evidence suggests an infectious component in the development of multiple sclerosis (MS) and, to date, some 20 bacteria and viruses have been associated with the disease. Recent independent sets of studies have implicated the respiratory bacterium Chlamydia pneumoniae and human herpes virus 6 (HHV-6) in the pathogenesis of MS. However, as is the case for essentially all earlier microbial associations, experimental evidence linking either this bacterium or this virus to MS is equivocal. We review the published reports concerning involvement of C. pneumoniae and HHV-6 in MS, and data relating to possession of the APOE epsilon 4 allele, which some studies indicate might influence how these or other pathogens affect disease genesis. Based on the large set of inconsistent observations available and given important new information regarding the neuropathology of MS, we contend that no conclusion is possible at this point regarding the potential role of either C. pneumoniae or HHV-6 in MS. We therefore propose future studies that should clarify whether, and if so how, these and other organisms function in the pathogenesis of this disease.

Providing pharmaceutical care to the multiple sclerosis patient

OBJECTIVE

To review the pathophysiology, symptoms, and treatment of multiple sclerosis (MS).

DATA SOURCES

Recently published clinical literature identified through review of articles abstracted at MEDLINE. Search terms included multiple sclerosis, interferon beta, glatiramer acetate, mitoxantrone, treatment, symptoms, steroids, etiology, and neutralizing antibodies.

STUDY SELECTION

Performed manually by the authors.

DATA EXTRACTION

Performed manually by the authors.

DATA SYNTHESIS

MS is a chronic disease of the central nervous system that most often strikes patients in their early 30s. Noticeable geographic, ethnic, racial, and sex differences in incidence remain unexplained. Diagnosis relies heavily on the presence of neurologic signs and symptoms, and magnetic resonance imaging of the brain is increasingly useful. Treatment with steroids, interferon beta-1b (Betaseron-Berlex) and interferon beta-1a (Avonex-Biogen; Rebif-Serono), and glatiramer acetate (Copaxone-Teva) can produce periods of remission in patients with MS. Management of adverse medication effects and disease-related symptoms of fatigue, pain, and bladder dysfunction is important in these patients.

CONCLUSION

MS is currently incurable but largely treatable. Research has produced promising new medications, and investigational therapies hold promise for better treatment of this debilitating condition.