Interaction of the Gut Microbiome and Immunity in Multiple Sclerosis: Impact of Diet and Immune Therapy

The bidirectional communication between the gut and central nervous system (CNS) through microbiota is known as the microbiota-gut-brain axis. The brain, through the enteric neural innervation and the vagus nerve, influences the gut physiological activities (motility, mucin, and peptide secretion), as well as the development of the mucosal immune system. Conversely, the gut can influence the CNS via intestinal microbiota, its metabolites, and gut-homing immune cells. Growing evidence suggests that gut immunity is critically involved in gut-brain communication during health and diseases, including multiple sclerosis (MS). The gut microbiota can influence the development and function of gut immunity, and conversely, the innate and adaptive mucosal immunity can influence microbiota composition. Gut and systemic immunity, along with gut microbiota, are perturbed in MS. Diet and disease-modifying therapies (DMTs) can affect the composition of the gut microbial community, leading to changes in gut and peripheral immunity, which ultimately affects MS. A high-fat diet is highly associated with gut dysbiosis-mediated inflammation and intestinal permeability, while a high-fiber diet/short-chain fatty acids (SCFAs) can promote the development of Foxp3 Tregs and improvement in intestinal barrier function, which subsequently suppress CNS autoimmunity in the animal model of MS (experimental autoimmune encephalomyelitis or EAE). This review will address the role of gut immunity and its modulation by diet and DMTs via gut microbiota during MS pathophysiology.

Fecal Lcn-2 level is a sensitive biological indicator for gut dysbiosis and intestinal inflammation in multiple sclerosis

Multiple Sclerosis (MS) has been reported to be associated with intestinal inflammation and gut dysbiosis. To elucidate the underlying biology of MS-linked gut inflammation, we investigated gut infiltration of immune cells during the development of spontaneous experimental autoimmune encephalomyelitis (EAE) in humanized transgenic (Tg) mice expressing HLA-DR2a and human T cell receptor (TCR) specific for myelin basic protein peptide (MBP87-99)/HLA-DR2a complexes. Strikingly, we noted the simultaneous development of EAE and colitis, suggesting a link between autoimmune diseases of the central nervous system (CNS) and intestinal inflammation. Examination of the colon in these mice revealed the infiltration of MBP-specific Th17 cells as well as recruitment of neutrophils. Furthermore, we observed that fecal Lipocalin-2 (Lcn-2), a biomarker of intestinal inflammation, was significantly elevated and predominantly produced by the gut-infiltrating neutrophils. We then extended our findings to MS patients and demonstrate that their fecal Lcn-2 levels are significantly elevated compared to healthy donors (HDs). The elevation of fecal Lcn-2 levels correlated with reduced bacterial diversity and increased levels of other intestinal inflammation markers including neutrophil elastase and calprotectin. Of interest, bacteria thought to be beneficial for inflammatory bowel disease (IBD) such as Anaerobutyricum, Blautia, and Roseburia, were reduced in fecal Lcn-2-high MS patients. We also observed a decreasing trend in serum acetate (a short-chain fatty acid) levels in MS Lcn-2-high patients compared to HDs. Furthermore, a decrease in the relative abundance of Blautia massiliensis was significantly associated with a reduction of acetate in the serum of MS patients. This study suggests that gut infiltration of Th17 cells and recruitment of neutrophils are associated with the development of gut dysbiosis and intestinal inflammation, and that fecal Lcn-2 level is a sensitive biological indicator for gut dysbiosis in multiple sclerosis.

Monthly triple-dose gadolinium administration: potential associations with leukopenia, hypophosphatemia, and bone marrow T1 hyperintensity

Objective

Monthly scanning with triple-dose gadopentetate dimeglumine has been shown to be associated with progressive increases in bone T1 hyperintensity, hypophosphatemia, and leukopenia. This study was performed to retrospectively investigate the potential associations among these phenomena.

Methods

This retrospective analysis involved patients who had received monthly triple-dose gadopentetate dimeglumine for up to 2 years as part of treatment for multiple sclerosis. Monthly magnetic resonance imaging scans of the brain (n = 67) were segmented to evaluate the signal intensity in the cranial marrow. Potential associations among the marrow T1 hyperintensity, serum phosphate concentration, and white blood cell count were examined.

Results

Patients in the no leukopenia group showed a statistically significant mean monthly increase in the bone marrow signal-to-noise ratio of 0.0430/month. Patients in the leukopenia group showed a mean monthly increase in the bone marrow signal-to-noise ratio of 0.0398/month, but this was not statistically significant. Patients in the hypophosphatemia group were significantly less likely to develop leukopenia than patients who had never developed hypophosphatemia.

Conclusions

Although monthly administration of triple-dose gadopentetate dimeglumine over 13 months has been associated with progressive increases in leukopenia, hypophosphatemia, and T1 signal intensity of bone, this study showed an inverse relationship between leukopenia and hypophosphatemia.

Effect of switching glatiramer acetate formulation from 20 mg daily to 40 mg three times weekly on immune function in multiple sclerosis

Background

Many RRMS patients who had been treated for over 20 years with GA 20 mg/ml daily (GA20) switched to 40 mg/ml three times-a-week (GA40) to reduce injection-related adverse events. Although GA40 is as effective as GA20 in reducing annualized relapse rate and MRI activity, it remains unknown how switching to GA40 from GA20 affects the development of pathogenic and regulatory immune cells.

Objective

To investigate the difference in immunological parameters in response to GA20 and GA40 treatments.

Methods

We analyzed five pro-inflammatory cytokines (IL-1β, IL-23, IL-12, IL-18, TNF-α), and three anti-inflammatory/regulatory cytokines (IL-10, IL-13, and IL-27) in serum. In addition, we analyzed six cytokines (IFN-γ, IL-17A, GM-CSF, IL-10, IL-6, and IL-27) in cultured PBMC supernatants. The development of Th1, Th17, Foxp3 Tregs, M1-like, and M2-like macrophages were examined by flow cytometry. Samples were analyzed before and 12 months post switching to GA40 or GA20.

Results

Pro- and anti-inflammatory cytokines were comparable between the GA40 and GA20 groups. Development of Th1, Th17, M1-like macrophages, M2-like macrophages, and Foxp3 Tregs was also comparable between the two groups.

Conclusions

The immunological parameters measured in RRMS patients treated with GA40 three times weekly are largely comparable to those given daily GA20 treatment.

Dimethyl Fumarate Suppresses Demyelination and Axonal Loss through Reduction in Pro-Inflammatory Macrophage-Induced Reactive Astrocytes and Complement C3 Deposition

Dimethyl fumarate (DMF) is an oral agent for relapsing-remitting multiple sclerosis (RRMS). In this study, we investigated the therapeutic mechanism of DMF using experimental autoimmune encephalomyelitis (EAE). DMF treatment decreased the proliferation of T cells and the production of IL-17A and GM-CSF. DMF treatment also decreased the development and/or infiltration of macrophages in the central nervous system (CNS), and reduced the ratio of iNOS⁺ pro-inflammatory macrophage versus Ym1⁺ immunomodulatory macrophages. Furthermore, DMF treatment suppressed the deposition of complement C3 (C3) and development of reactive C3⁺ astrocytes. The decrease in iNOS⁺ macrophages, C3⁺astrocytes, and C3 deposition in the CNS resulted in the reduction in demyelination and axonal loss. This study suggests that the beneficial effects of DMF involve the suppression of iNOS⁺ pro-inflammatory macrophages, C3⁺ astrocytes, and deposition of C3 in the CNS.

Potential Risks and Benefits of Multiple Sclerosis Immune Therapies in the COVID-19 Era: Clinical and Immunological Perspectives

Coronavirus SARS-CoV2 has emerged as one of the greatest infectious disease health challenges in a century. Patients with multiple sclerosis (MS) have a particular vulnerability to infections through their use of immunosuppressive disease-modifying therapies (DMTs). Specific DMTs pose particular risk based on their mechanisms of action (MOA). As a result, patients require individualized approaches to starting new treatments and continuation of therapy. Additionally, vaccinations must be considered carefully, and individuals on long-term B cell-depleting therapies may have diminished immune responses to vaccination, based on preserved T cells and diminished but present antibody titers to influenza vaccines. We review the immunology behind these treatments and their impact on COVID-19, as well as the current recommendations for best practices for use of DMTs in patients with MS.

Surface Layer Protein A Expressed in Clostridioides difficile DJNS06-36 Possesses an Encephalitogenic Mimotope of Myelin Basic Protein

Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS). Recent studies suggest that migration of Th1 and Th17 cells specific for enteric bacteria from the gut to the CNS may lead to the initiation and/or exacerbation of autoimmune diseases including MS. Human leukocyte antigen (HLA)-DR15 is an MHC class II (MHCII) haplotype highly associated with the development of MS that contains the two HLA-DRB* genes, DRB1*1501 (DR2b) and DRB5*0101 (DR2a). To identify enteric bacteria which harbor antigenic epitopes that activate myelin-specific T cells and drive CNS inflammation, we screened for enteric bacteria which express cross-reactive epitopes ('mimotopes') of an immunodominant myelin basic protein 89-98 (MBP_89-98) epitope. Based on known MHCII HLA-DR2a amino acid binding motifs and cultivation with splenic T cells isolated from MBP-T cell receptor (TCR)/DR2a transgenic (Tg) mice, we discovered that a certain variant of surface layer protein A (SLPA), which is expressed by a subtype of Clostridioides difficile, contains an amino acid sequence that activates MBP_89-98-reactive T cells. Furthermore, activation of MBP-specific T cells by SLPA upon active immunization induced experimental autoimmune encephalomyelitis (EAE) in MBP-TCR/DR2a Tg mice. This study suggests that a unique strain of C. difficile possesses an encephalitogenic mimotope of MBP that activates autoreactive, myelin-specific T cells.

MRI demonstration of gadolinium deposition in bone after monthly triple-dose gadopentetate dimeglumine and correlation with frequency of hypophosphatemia

OBJECTIVES

We retrospectively analyzed data of the BECOME trial to investigate whether serial administration of triple-dose (3-dose) gadopentetate dimeglumine would result in the development of T1 signal-to-noise (S/N) changes in the cranial diploic space and whether S/N changes correlated with on-study hypophosphatemia.

METHODS

Signal intensity analysis was performed on the first year's data of the BECOME trial using 3-dose Gd (14 months, maximum number of doses, 39, mean: 36). Routine blood and urine tests were obtained each month for safety monitoring. Linear mixed regression modeling with random intercept was used to analyze monthly signal-to-noise ratio (S/N = Bone/Air) using an ROI of the diploic space created from T2W images and overlaid on T1FS (T1 fat-saturated) images. Incidence of phosphate abnormalities was analyzed using the general estimation equation; correlation of phosphate and S/N change was achieved with type 3 test of fixed effects.

RESULTS

Cranial diploic space T1FS S/N increased over 14 months: S/N = 0.039 mean monthly increase (S.E. 0.008; p < 0.0001). Subjects with consistently normal phosphate levels (n = 32) experienced more of a S/N increase than patients with at least one episode of hypophosphatemia (n = 35) (0.057 vs. 0.023, respectively, p = 0.037). Those with moderate hypophosphatemia demonstrated no significant S/N increase.

CONCLUSION

Monthly administration of 3-dose gadopentetate dimeglumine is associated with development of increased S/N on T1FS imaging in the cranial diploic space, suggesting Gd retention in bone. Our data suggests MRI could be used as a noninvasive method of tracking Gd retention in bone, which was more pronounced in patients with normal phosphate levels.

Insight into the mechanism of action of dimethyl fumarate in multiple sclerosis

Dimethyl fumarate (DMF) is an oral, disease-modifying agent for the treatment of relapsing-remitting multiple sclerosis (RRMS). However, details regarding its mode of action are still emerging. It is believed that the mode of action of DMF involves both nuclear factor erythroid-derived 2-related factor (Nrf2)-dependent and independent pathways, which lead to an anti-inflammatory immune response due to type II myeloid cell and Th2 cell differentiation and neuroprotection. In this review, we will focus on the molecular and signaling effects of DMF that lead to changes in peripheral immune cell composition and function, alteration in CNS cell-specific functions, and effect on the blood-brain barrier.

Gut dysbiosis breaks immunological tolerance toward the central nervous system during young adulthood

Multiple sclerosis (MS) is an immune mediated disease targeting the central nervous system (CNS) mainly in young adults, and a breakage of immune tolerance to CNS antigens has been suggested to initiate CNS autoimmunity. Recent studies have suggested that gut microbiota affects the development of autoimmune diseases and alterations in the gut microbiota, termed gut dysbiosis, are associated with MS. However, it is still unknown how gut dysbiosis affects the onset and/or progression of CNS autoimmunity. In this study, we investigated the effects of gut dysbiosis on the development of CNS autoimmunity in humanized transgenic mice expressing the MS- associated HLA-DR gene, DR2a, and the T cell receptor (TCR) gene specific for MBP87-99/DR2a that were derived from an MS patient. We show here that the induction of gut dysbiosis triggers the development of spontaneous experimental autoimmune encephalomyelitis (EAE) during adolescence and early adulthood, while increase in immunological tolerance with aging suppresses the disease onset after late young adulthood. Furthermore, gut dysbiosis induces the expression of complement C3 and production of the anaphylatoxin C3a, and down-regulates the expression of the Foxp3 gene in Tregs and anergy-related E3-ubiquitin ligase genes in CD4+CD25− T cells. Consequently, gut dysbiosis was able to trigger the development of encephalitogenic T cells and promote the induction of EAE during the young adulthood age-window. This data suggests that gut dysbiosis increases the risk for CNS autoimmunity in young adulthood through the up-regulation of the complement C3 gene and down-regulation of Foxp3 and E3-ubiquitin ligase genes.

IL-27: a potential biomarker for responders to glatiramer acetate therapy

Glatiramer acetate (GA) is an FDA-approved efficacious drug for the treatment of relapsing-remitting multiple sclerosis (RRMS). However, this treatment is not effective for all RRMS patients. Therefore, it is important to identify reliable biomarkers that can predict a beneficial clinical response to GA therapy. Since an increase in IL-27 has been demonstrated to suppress autoimmune and allergic diseases of inflammatory origin, we examined the effect of GA on the production of IL-27. We observed that IL-27 production in PBMCs cultured with GA was heterogeneous amongst MS patients and healthy donors (HD), and thus, defined these MS patients as either efficient, weak, or non-IL-27 producers. Interestingly, GA could induce the expression of the IL-27p28 subunit more efficiently than the IL-27 EBI3 subunit, and the production of IL-27 depended on MHC class II binding by GA. In addition, we found that GA could augment Toll-like receptor (TLR)-mediated IL-27 production. Importantly, serum production of IL-27 and IL-10 was significantly increased at 6months during GA therapy in clinical responders to GA, but not in GA non-responders. Altogether, our data suggest that GA-induced IL-27 may represent a therapeutic mechanism of GA-mediated immunomodulation and that GA-mediated IL-27 production in PBMCs is worth exploring as a biomarker to screen for GA responders prior to the initiation of GA treatment.

Brain health: time matters in multiple sclerosis

INTRODUCTION

We present international consensus recommendations for improving diagnosis, management and treatment access in multiple sclerosis (MS). Our vision is that these will be used widely among those committed to creating a better future for people with MS and their families.

METHODS

Structured discussions and literature searches conducted in 2015 examined the personal and economic impact of MS, current practice in diagnosis, treatment and management, definitions of disease activity and barriers to accessing disease-modifying therapies (DMTs).

RESULTS

Delays often occur before a person with symptoms suggestive of MS sees a neurologist. Campaigns to raise awareness of MS are needed, as are initiatives to improve access to MS healthcare professionals and services. We recommend a clear treatment goal: to maximize neurological reserve, cognitive function and physical function by reducing disease activity. Treatment should start early, with DMT and lifestyle measures. All parameters that predict relapses and disability progression should be included in the definition of disease activity and monitored regularly when practical. On suboptimal control of disease activity, switching to a DMT with a different mechanism of action should be considered. A shared decision-making process that embodies dialogue and considers all appropriate DMTs should be implemented. Monitoring data should be recorded formally in registries to generate real-world evidence. In many jurisdictions, access to DMTs is limited. To improve treatment access the relevant bodies should consider all costs to all parties when conducting economic evaluations and encourage the continuing investigation, development and use of cost-effective therapeutic strategies and alternative financing models.

CONCLUSIONS

The consensus findings of an international author group recommend a therapeutic strategy based on proactive monitoring and shared decision-making in MS. Early diagnosis and improved treatment access are also key components.

Predictive cytokine biomarkers of clinical response to glatiramer acetate therapy in multiple sclerosis

A prospective study of 62 patients with relapsing-remitting multiple sclerosis (RRMS) treated with Glatiramer acetate (GA) was conducted to evaluate the value of baseline and treatment-modulated cytokines in predicting the clinical response to the drug after 2years of therapy. There were 32 responders and 30 non-responders. GA upregulated Th2/regulatory cytokines and inhibited Th1 cytokines in sera or PBMC supernatants 3 and 6months into treatment. We found two prognostic models with clinical utility. A model based on IL-18 at baseline, the change in TNFa from baseline to 3months, the change in IL-4 from baseline to 6months, and the change in the log of the ratio of TNFa/IL-4 from baseline to 6months had an area under the curve (AUC) of 0.80. A high IL-18 level at baseline and a reduction of TNF-alpha over time are associated with a response to GA. Although the study identified predictive biomarkers of clinical response to GA, the results will need to be validated in other data sets.

Further understanding of the immunopathology of multiple sclerosis: impact on future treatments

INTRODUCTION

The understanding of the immunopathogenesis of multiple sclerosis (MS) has expanded with more research into T-cell subtypes, cytokine contributors, B-cell participation, mitochondrial dysfunction, and more. Treatment options have rapidly expanded with three relatively recent oral therapy alternatives entering the arena.

AREAS COVERED

In the following review, we discuss current mechanisms of immune dysregulation in MS, how they relate to current treatments, and the impact these findings will have on the future of therapy. Expert commentary: The efficacy of these medications and understanding their mechanisms of actions validates the immunopathogenic mechanisms thought to underlie MS. Further research has exposed new targets, while new promising therapies have shed light on new aspects into the pathophysiology of MS.

Dysregulation of immune response to enteric bacteria triggers the development of spontaneous experimental autoimmune encephalomyelitis

Multiple sclerosis (MS) is an autoimmune disease against the central nervous system (CNS). Although the etiology of MS is still unknown, breakage of peripheral immune tolerance to CNS antigens is believed to be an initial event of CNS autoimmune diseases. It has been indicated that gut microbiota is an important environmental risk factor in MS/EAE pathogenesis; however, the exact mechanism for pathogenesis has not been elucidated.

To examine how the immune tolerance to myelin basic protein (MBP) is broken, we created a humanized transgenic (Tg) mice that express MS-associated HLA-DR2a and MBP-specific TCR (3A6 TCR) genes isolated from an MS patient. The 3A6/DR2a Tg mice develop EAE spontaneously, and antibiotic treatment, which can reduce the population of commensal bacteria, was found to abolish the development of spontaneous EAE. Since fecal IgM is a marker of expansion of enteric bacteria, we examined the association of fecal IgM with spontaneous EAE development. Interestingly, raised levels of fecal IgM and expansion of enteric bacteria were associated with the development of spontaneous EAE, and a massive infiltration of MBP-specific Tg T cells and neutrophils, along with complement deposits, were detected in the colon of spontaneous EAE mice. Furthermore, MBP-specific GM-CSF+ Th1 and Th17 cells were expanding in the colon but not in the small intestine, and CNS-homing integrin, α4β1, was highly up-regulated in the MBP-specific T cells in the mesenteric lymph nodes in the spontaneous EAE mice.

These data suggest that enteric bacteria-mediated dysregulation of gut immunity may be involved in the initiation and progression of CNS-autoimmune diseases.

Estriol combined with glatiramer acetate for women with relapsing-remitting multiple sclerosis: a randomised, placebo-controlled, phase 2 trial

BACKGROUND

Relapses of multiple sclerosis decrease during pregnancy, when the hormone estriol is increased. Estriol treatment is anti-inflammatory and neuroprotective in preclinical studies. In a small single-arm study of people with multiple sclerosis estriol reduced gadolinium-enhancing lesions and was favourably immunomodulatory. We assessed whether estriol treatment reduces multiple sclerosis relapses in women.

METHODS

We did a randomised, double-blind, placebo-controlled phase 2 trial at 16 academic neurology centres in the USA, between June 28, 2007, and Jan 9, 2014. Women aged 18-50 years with relapsing-remitting multiple sclerosis were randomly assigned (1:1) with a random permuted block design to either daily oral estriol (8 mg) or placebo, each in combination with injectable glatiramer acetate 20 mg daily. Patients and all study personnel, except for pharmacists and statisticians, were masked to treatment assignment. The primary endpoint was annualised relapse rate after 24 months, with a significance level of p=0.10. Relapses were confirmed by an increase in Expanded Disability Status Scale score assessed by an independent physician. Analysis was by intention to treat. The trial is registered with ClinicalTrials.gov, number NCT00451204.

FINDINGS

We enrolled 164 patients: 83 were allocated to the estriol group and 81 were allocated to the placebo group. The annualised confirmed relapse rate was 0.25 relapses per year (95% CI 0.17-0.37) in the estriol group versus 0.37 relapses per year (0.25-0.53) in the placebo group (adjusted rate ratio 0.63, 95% CI 0.37-1.05; p=0.077). The proportion of patients with serious adverse events did not differ substantially between the estriol group and the placebo group (eight [10%] of 82 patients vs ten [13%] of 76 patients). Irregular menses were more common in the estriol group than in the placebo group (19 [23%] vs three [4%], p=0.0005), but vaginal infections were less common (one [1%] vs eight [11%], p=0.0117). There were no differences in breast fibrocystic disease, uterine fibroids, or endometrial lining thickness as assessed by clinical examination, mammogram, uterine ultrasound, or endometrial lining biopsy.

INTERPRETATION

Estriol plus glatiramer acetate met our criteria for reducing relapse rates, and treatment was well tolerated over 24 months. These results warrant further investigation in a phase 3 trial.

FUNDING

National Institutes of Health, National Multiple Sclerosis Society, Conrad N Hilton Foundation, Jack H Skirball Foundation, Sherak Family Foundation, and the California Community Foundation.

MMP-9 expression is increased in B lymphocytes during multiple sclerosis exacerbation and is regulated by microRNA-320a

B cells are necessary to maintain disease activity in relapsing multiple sclerosis (MS) and produce matrix metallopeptidase-9 (MMP-9), which disrupts the blood-brain barrier. MMP-9 protein expression was increased and expression of microRNA-320a (miR-320a), which targets MMP-9 mRNA, was significantly decreased in B lymphocytes of MS patients during a disease relapse compared to remission. Functional significance of these findings was demonstrated by transfecting human B lymphocytes with miR-320a inhibitor, which led to increased MMP-9 expression and secretion. In summary, expression of miR-320a is decreased in B cells of MS patients and may contribute to increased blood-brain barrier permeability and neurological disability.

Early treatment with anti-VLA-4 mAb can prevent the infiltration and/or development of pathogenic CD11b+CD4+ T cells in the CNS during progressive EAE

Natalizumab is a humanized monoclonal antibody against the leukocyte adhesion molecule very late antigen (VLA)-4, and is currently an approved therapy for patients with relapsing-remitting multiple sclerosis (RRMS). However, it is unknown whether natalizumab is beneficial for progressive forms of MS. Therefore, we assessed the effects of anti-VLA-4 monoclonal antibody (mAb) therapy in a progressive experimental autoimmune encephalomyelitis (EAE) mouse model. Notably, we found that early therapy could significantly reduce the severity of progressive EAE, while treatment initiated at an advanced stage was less efficient. Furthermore, we observed the accumulation of a novel subset of GM-CSF-producing CD11b+CD4+ T cells in the CNS throughout disease progression. Importantly, early therapeutic anti-VLA-4 mAb treatment suppressed the accumulation of these GM-CSF-producing CD11b+CD4+ T cells in the CNS along with activated microglia/macrophages populations, and also conferred a protective effect against inflammation-mediated neurodegeneration, including demyelination and axonal loss. Collectively, our data suggest that early treatment with anti-VLA-4 mAb can provide neuroprotection against progressive CNS autoimmune disease by preventing the accumulation of pathogenic GM-CSF-producing CD11b+CD4+ T cells in the CNS.

Use of Magnetic Resonance Imaging as Well as Clinical Disease Activity in the Clinical Classification of Multiple Sclerosis and Assessment of Its Course: A Report from an International CMSC Consensus Conference, March 5-7, 2010

It has recently been suggested that the Lublin-Reingold clinical classification of multiple sclerosis (MS) be modified to include the use of magnetic resonance imaging (MRI). An international consensus conference sponsored by the Consortium of Multiple Sclerosis Centers (CMSC) was held from March 5 to 7, 2010, to review the available evidence on the need for such modification of the Lublin-Reingold criteria and whether the addition of MRI or other biomarkers might lead to a better understanding of MS pathophysiology and disease course over time. The conference participants concluded that evidence of new MRI gadolinium-enhancing (Gd+) T1-weighted lesions and unequivocally new or enlarging T2-weighted lesions (subclinical activity, subclinical relapses) should be added to the clinical classification of MS in distinguishing relapsing inflammatory from progressive forms of the disease. The consensus was that these changes to the classification system would provide more rigorous definitions and categorization of MS course, leading to better insights as to the evolution and treatment of MS.

The Combined Effect of Nursing Support and Adverse Event Mitigation on Adherence to Interferon Beta-1b Therapy in Early Multiple Sclerosis: The START Study

There is limited clinical evidence on the impact of nurse support and adverse event (AE) mitigation techniques on adherence to interferon beta-1b (IFNβ-1b) therapy in multiple sclerosis (MS) in a real-world setting. The aim of the Success of Titration, analgesics, and BETA nurse support on Acceptance Rates in MS Treatment (START) trial was to assess the combined effect of titration, analgesics, and BETA (Betaseron Education, Training, Assistance) nurse support on adherence to IFNβ-1b therapy in patients with early-onset MS and to evaluate safety. Participants were instructed to titrate IFNβ-1b and use analgesics to minimize flu-like symptoms. All received BETA nurse follow-up at frequent intervals: live training, two telephone calls during the first month of therapy, and monthly calls thereafter. Participants were considered adherent if they took at least 75% of the total prescribed doses over 12 months (≥75% compliance). Safety was monitored via reported AEs and laboratory test results. Participants who took at least one IFNβ-1b dose over 12 months were analyzed (N = 104); 73.8% of participants completed the study. The mean age of participants was 37.2 years; 72.1% were women and 78.8% were white. Ninety participants had relapsing-remitting MS and 14 had clinically isolated syndrome. The mean compliance rate, reported for 96 participants with complete dose interruption records, was 84.4%. At 12 months, 78.1% of participants were considered adherent. The serious adverse event rate was 9.6%; most events were unrelated to therapy. Thus in the START study, in which participants received nursing support combined with dose titration and use of analgesics, the majority of participants were adherent to therapy.

Effect of interferon beta-1a on B7.1 and B7.2 B-cell expression and its impact on T-cell proliferation

The effect of pharmacologically relevant doses of interferon (IFN) β-1a on B-cell expression of B7.1 and B7.2 was investigated. Culture of peripheral blood mononuclear cells with IFN β-1a 100 IU/mL decreased B-cell expression of B7.1 and increased B7.2 expression. Interleukin-10 in B cells was significantly enhanced by IFN β-1a. Anti-CD3 and anti-CD28 monoclonal antibody-mediated T-cell proliferations were partially suppressed in the presence of B cells pretreated with IFN β-1a. These data suggest that IFN β-1a and B cells can interact to play a beneficial role in the treatment of multiple sclerosis.

Hematopoietic progenitors express myelin basic protein and ensheath axons in Shiverer brain

Oligodendroglia are cells of the central nervous system (CNS) that form myelin sheath, which insulates neuronal axons. Neuropathologies of the CNS include dysmyelination of axons in multiple sclerosis and CNS trauma. Cell replacement is a promising but largely untested therapy for dysmyelination. Shiverer mouse, a genetic mutant that does not synthesize full-length myelin basic protein (MBP), a critical prerequisite protein in CNS myelin sheath formation, provides an unequivocal model for determining the potential of stem cells to become oligodendroglia. We demonstrate that adult wild-type mouse bone marrow stem cells can express MBP and ensheath axons when transplanted into Shiverer brain.

Are Periventricular Lesions Specific for Multiple Sclerosis?

BACKGROUND

The presence of periventricular lesions (PVL) on MRI scans is part of the revised McDonald multiple sclerosis (MS) diagnostic criteria. However, PVL can be found in other neurological diseases including stroke and migraine. Migraine is highly prevalent in patients with MS.

OBJECTIVE

To determine if PVL are specific for patients with MS compared to stroke and migraine.

METHODS

We studied patients diagnosed with clinically isolated syndrome (CIS), relapsing-remitting MS (RRMS), migraine, and ischemic stroke. The number, location and the volume of PVL were identified on brain MRI scans and analyzed.

RESULTS

The number and volume of PVL adjacent to the body and the posterior horn of the lateral ventricles were significantly increased on fluid-attenuated inversion recovery MRI in RRMS compared to migraine. There were no significant differences in the total number and volume of PVL in ischemic stroke patients compared to the age-matched RRMS patients nor in the number and volume of PVL adjacent to the anterior and temporal horns of the lateral ventricles on FLAIR images in migraine compared to CIS or RRMS.

CONCLUSION

In contrast to PVL adjacent to the body and the posterior horn of the lateral ventricles, PVL adjacent to the anterior and temporal horns of the lateral ventricles may not be specific for CIS/RRMS when compared to migraine, the disease highly prevalent among patients with MS. PVL are not specific for MS when compared to ischemic stroke.

Immune response during interferon beta-1b treatment in patients with multiple sclerosis who experienced relapses and those who were relapse-free in the START study

We measured immune markers in subjects with multiple sclerosis (MS) treated with IFNβ-1b for 12 months. IL-17 levels were significantly higher at Month 6 (p=0.036) in relapsing subjects while BDNF levels were significantly higher at Month 3 (p=0.028) in relapse-free subjects. Change from baseline in IL-4 levels inversely correlated with disability score whereas change from baseline in IL-10/IFN-gamma ratio inversely correlated with occurrence of relapses. CXCR3+CD8+ T-cells tended to be higher but declined with treatment in relapse-free compared with relapsing subjects. Findings show the potential of cytokine and neurotrophic factors as biomarkers of clinical response to IFNβ-1b.

Multiple sclerosis-linked and interferon-beta-regulated gene expression in plasmacytoid dendritic cells

The cause of multiple sclerosis (MS) is not known and the mechanism of interferon-beta, a disease-modifying treatment, is not well-understood. We studied gene expression in plasmacytoid dendritic cells (pDCs), antigen-presenting cells implicated in MS pathogenesis. PDCs were separated from healthy donors and MS patients at two time points: before and after initiation of treatment with interferon-beta. Expression of selected MS-linked and interferon-beta-regulated genes was validated with single assays. We have identified 60 genes which were abnormally expressed in MS patients and were corrected after treatment. These genes could be studied as potential MS biomarkers and possible therapeutic targets in MS.

Spontaneous development of encephalitogenic T cells is regulated by age-dependent induction of tolerance (123.11)

Multiple Sclerosis (MS) is an autoimmune disease against CNS and disease onset most often occurs in young adults, suggesting that aging is a critical factor for the development of MS. We examined the effect of aging on the induction of tolerance in the CNS-specific T cells and their differentiation into pathogenic Th1 and Th17 cells in the transgenic (Tg) mice that express HLA-DRB5*0101 and MBP-specific human TCR (3A6) genes isolated from an MS patient. The 3A6-TCR Tg CD4 T cells undergo thymic and peripheral deletion with aging and the surviving CD4 T cells undergo anergy in the periphery. In spite of induction of age-dependent tolerance induction in the MBP-specific CD4 T cells, 3A6 Tg CD4 T cells differentiate into Th1 and Th17 cells in the thymus, migrate into the periphery, and further differentiate into Th1 and Th17 encephalitogenic T cells spontaneously in 5-10-week-old young adult mice. However, increase in age-dependent tolerance reduces the spontaneous development of encephalitogenic T cells. These data suggest that spontaneous development of encephalitogenic T cells is dependent on the balance between age-dependent tolerance induction and spontaneous development of CNS-specific Th1 and Th17 cells.

Interferon beta-1a modulation of B cells (161.12)

Clinical studies have shown that IFNβ-1a reduces relapses and slows disease progression in relapsing multiple sclerosis (MS). Although the effect of IFNβ-1a on T cells has been extensively investigated, its effects on B cells are poorly understood. We examined the effect of IFNβ-1a on IL-10 production in B cells. B cells isolated from healthy donors were cultured with IFNβ-1a, and production of IL-10 was measured. IFNβ-1a enhanced IL-10 production in B cells in a dose dependent fashion. We also found that IFNβ-1a treatment increased the percentage of B-cells expressing B7.2 (CD86). To examine how IFNβ-1a mediated increase of B7.2 affects the proliferation of CD4+ T cells, CD4+ T cells were cultured with IFNβ-1a-treated or non-treated B cells, with or without anti-CD3. Anti-CD3 mAb-mediated T-cell proliferation was partially suppressed when B cells were treated with IFNβ-1a. Addition of anti-CTLA-4 mAb partially reversed the IFNβ-1a-mediated suppression of T-cell proliferation. These data suggest that IFNβ-1a-induced increase of B7.2 in B-cells may reduce the proliferation of CD4+ T cells through increased interaction of B7.2 with CTLA-4. In conclusion, in in vitro experiments, IFNβ-1a increases IL-10 production in B cells and can indirectly inhibit T-cell proliferation through up-regulation of B7.2 on B cells. These findings shed light on the mechanism of action of IFNβ-1a in MS.

Acute multiple sclerosis lesion: conversion of restricted diffusion due to vasogenic edema

It is widely accepted that acute demyelinating plaques in patients with multiple sclerosis (MS) demonstrate increased apparent diffusion coefficient (ADC) and increased diffusion weighted imaging (DWI) signals on MRI. These imaging characteristics in acute MS lesions have been postulated to be due to peripheral vasogenic edema that typically increases the ADC. This assumption is commonly used to differentiate stroke from MS lesions since acute and subacute stroke lesions demonstrate increased DWI signal with reduced ADC due to acute cytotoxic edema. We report a case of active relapsing-remitting MS with two new symptomatic contrast-enhancing lesions. The lesions had reduced diffusion on the ADC map in the early acute phase of MS exacerbation. The reduced ADC signal was subsequently "converted" to increased ADC signal that coincided with the development of profound peripheral vasogenic edema seen on T2-weighted images. To our knowledge, this is the first serial MRI study describing decreased ADC signal in the early acute phase of contrast-enhancing MS lesion. The implications of decreased diffusion in the acute phase of MS lesions for the disease pathogenesis are discussed.

Gastrointestinal tract is the place where encephalitogenic T cells develop in the spontaneous EAE mice (101.11)

Multiple sclerosis (MS) is an autoimmune disease exhibiting features of demeylination and axonal loss in the central nervous system (CNS). Although CNS-specific Th1 and Th17 cells have been suggested to initiate the disease, it is still unknown how these effector T cells develop in MS patients. To address this question, we have generated transgenic mice that express T cell receptor (TCR) genes specific for myelin basic protein (MBP) and HLA-DR2a genes that were isolated from an MS patient. The humanized MBP-TCR Tg mice developed spontaneous EAE. Interestingly Th1 and Th17 cells developed in the mesenteric lymph nodes and the colon more efficiently than in other lymphoid organs in the spontaneous EAE mice, and their development was much lower in the gastrointestinal (GI) tract of healthy MBP-TCR Tg mice. This data suggests that MBP-specific T cells differentiate into Th1 and Th17 encephalitogenic T cells in the colon and migrate into the CNS from mesenteric lymph nodes. Alternatively, MBP-specific Th1 and Th17 encephalitogenic T cells develop in the other lymphoid organs and preferentially migrate into the gut. Interestingly, CD4 T cells infiltrates in the CNS of spontaneous EAE mice expressed gut-homing receptors in addition to CNS-homing receptors. These data suggest that the GI-tract may be an important site for the differentiation of encephalitogenic T cells in spontaneous EAE mice.

Interferon-β inhibits toll-like receptor 9 processing in multiple sclerosis

OBJECTIVE

Viral infections have been implicated in the pathogenesis of multiple sclerosis (MS). Plasmacytoid dendritic cells (pDCs) are present in peripheral blood, cerebrospinal fluid, and brain lesions of MS patients. pDCs sense viral DNA via Toll-like receptor 9 (TLR9), which has to be cleaved from the N-terminal to become functional (TLR9 processing). pDCs activated with TLR9 agonists promote T-helper type 1 (Th1)/T-helper type 17 (Th17) responses. In the animal model of MS, TLR9 agonists can induce disease. We hypothesized that pDCs are inhibited by disease-modifying therapy such as interferon (IFN)-β, consequently decreasing the frequency of MS attacks.

METHODS

We separated pDCs from healthy subjects and patients diagnosed with relapsing-remitting MS and clinically isolated syndrome. Cytokine secretion by pDCs activated with TLR9 agonists was measured by enzyme-linked immunosorbent assay and multianalyte profiling. TLR9 gene and protein expression was studied by DNA microarrays and western blot.

RESULTS

In untreated patients, pDCs activated with TLR9 agonists produced increased levels of IFN-α, a Th1-promoting cytokine, as compared to healthy subjects. In IFN-β-treated patients, activated pDCs had decreased ability to produce both IFN-α and the proinflammatory cytokines interleukin (IL)-6 and tumor necrosis factor α as compared to untreated patients. pDCs separated from IFN-β-treated patients had significantly reduced levels of the processed TLR9 protein but normal levels of the full-length TLR9 protein and TLR9 gene expression as compared to untreated patients.

INTERPRETATION

This finding represents a novel immunomodulatory mechanism of IFN-β: inhibition of TLR9 processing. This results in decreased activation of pDCs by viral pathogens and, thus, may affect the frequency of MS exacerbations.

Plasmacytoid dendritic cells in multiple sclerosis: chemokine and chemokine receptor modulation by interferon-beta

Plasmacytoid dendritic cells (pDCs) are present in peripheral blood, leptomeninges and demyelinating lesions in patients with multiple sclerosis (MS). The ability of pDCs to produce chemokines and express the chemokine receptor CCR7 in MS is not known. We studied pDCs in MS patients and healthy subjects. The ability of pDCs to up-regulate CCR7 was significantly increased in untreated MS patients as compared to healthy subjects. IFN-beta treatment significantly inhibited TLR9 agonist-specific secretion of chemokines, which are ligands for CCR5-positive Th1 cells (CCL3, CCL4, and CCL5), and impaired TLR9 agonist-induced up-regulation of CCR7 and IFN-alpha in MS patients. This finding represents a new immunomodulatory effect of IFN-beta in patients with multiple sclerosis.

Interferon-beta mechanisms of action in multiple sclerosis

ABSTRACT Multiple sclerosis (MS) is a chronic autoimmune disease of the CNS characterized by inflammation, demyelination, and axonal injury. These pathologic effects are manifested in clinical symptoms of relapse and disability. Various disease-modifying therapies have been developed in recent years to modulate the body's immune response. Among the most widely used are the beta interferons (IFNbeta). All produce comparable biological effects and are approved for the treatment of relapsing-remitting MS (RRMS). Although the precise mechanisms through which IFNbeta achieves its antiinflammatory and immunomodulatory effects remain uncertain, several modes of action have been proposed, including inhibition of T-cell activation and proliferation; apoptosis of autoreactive T cells; induction of regulatory T cells; inhibition of leukocyte migration across the blood-brain barrier; cytokine modulation; and potential antiviral activity. Endogenously produced IFNbeta in the injured brain is also now believed to contribute to mediation of antiinflammatory and regenerative effects. All these mechanisms are believed to underlie the therapeutic effect of IFNbeta in the treatment of RRMS.

Recognizing and treating suboptimally controlled multiple sclerosis: steps toward regaining command

OBJECTIVE

The therapies available today for multiple sclerosis (MS) reduce but do not fully control disease activity. The objective of this article is to review the definitions of and treatments for suboptimally controlled MS and highlight the challenges faced by clinicians to increase awareness of recognizing and managing patients with suboptimally controlled MS.

METHODS

Published literature describing treatment failure, treatment optimization paradigms or algorithms, clinical studies of therapies in patients with suboptimally controlled MS, or case reports of management of patients with suboptimally controlled MS were identified from searches of EMBASE and MEDLINE. This was supplemented with case reports and discussions from an expert panel meeting of MS specialists focused on the diagnosis and treatment of suboptimally controlled MS.

RESULTS

Several groups have created recommendations for evaluating suboptimal response to disease-modifying drugs (DMDs) in MS. Currently no robust evidence-based data exist to guide treatment decisions in patients who have suboptimal response to a particular therapy. In the absence of data, several treatment paradigms for suboptimally controlled MS have been proposed using a step therapy or platform therapy approach. Therapy modifications require consideration of disease- and patient-specific factors while accounting for the risk-benefit profile of the agent(s). Unapproved drugs and combination therapies should be reserved as agents of last resort because of the experimental nature of these treatments.

CONCLUSIONS

In the absence of evidence-based data, identifying and treating MS patients with suboptimal response to the available platform therapies remains challenging. Developing algorithms able to quantify breakthrough disease activity and suboptimal response to DMDs in individual MS patients remains an important target for the MS community. Consideration should be given for all reasons why a particular DMD may not be working for a given patient and for the use of an individualized step therapy.

Protective autoimmunity in the nervous system

The immune system can play both detrimental and beneficial roles in the nervous system. Multiple arms of the immune system, including T cells, B cells, NK cells, mast cells, macrophages, dendritic cells, microglia, antibodies, complement and cytokines participate in limiting damage to the nervous system during toxic, ischemic, hemorrhagic, infective, degenerative, metabolic and immune-mediated insults and also assist in the process of repair after injury has occurred. Immune cells have been shown to produce neurotrophic growth factors and interact with neurons and glial cells to preserve them from injury and stimulate growth and repair. The immune system also appears to participate in proliferation of neural progenitor stem cells and their migration to sites of injury. Neural stem cells can also modify the immune response in the central and peripheral nervous system to enhance neuroprotective effects. Evidence for protective and reparative functions of the immune system has been found in diverse neurologic diseases including traumatic injury, ischemic and hemorrhagic stroke, multiple sclerosis, infection, and neurodegenerative diseases (Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis). Existing therapies including glatiramer acetate, interferon-beta and immunoglobulin have been shown to augment the protective and regenerative aspects of the immune system in humans, and other experimental interventions such as vaccination, minocycline, antibodies and neural stem cells, have shown promise in animal models of disease. The beneficent aspects of the immune response in the nervous system are beginning to be appreciated and their potential as pharmacologic targets in neurologic disease is being explored.

Pathogenesis of myelin/oligodendrocyte damage in multiple sclerosis

Substantial evidence supports autoimmune activity as the etiologic mechanism underlying multiple sclerosis (MS). Both the innate and the adaptive arms of the immune system are involved in the aberrant response to several antigens associated with the myelin sheath and oligodendrocytes (OGCs) after the activation of immune cells by self- or cross-reactive microbial pathogens. The CD4(+) Th1 cell, in particular, has been implicated, but it is abetted by a variety of other cell types (CD8(+) cells, B cells, macrophages, and microglia) and soluble products (proteases, cytokines, and nitric oxide [NO]) that act both outside of and within the CNS. This review describes recent and salient findings from animal models and human clinical studies that have established our current understanding of the distinct steps in the development of immune autoreactivity that culminates in the CNS lesions associated with MS.

Cytokine changes during interferon-beta therapy in multiple sclerosis: correlations with interferon dose and MRI response

We investigated serum (IL-10 and IL-12p70) and cellular cytokine levels (IL-10, IL-12p40, IL-12p70, IFN-gamma) in stimulated PBMC over 24 weeks in 15 relapsing-remitting multiple sclerosis (MS) patients randomized to receive once-weekly (qw) IFN-beta-1a 30 microg intramuscularly (IM) (n=8) or three-times-weekly (tiw) IFN-beta-1a 44 microg subcutaneously (SC) (n=7). Overall, IFN-beta treatment increased cellular IL-10 (p<0.01) levels and the ratios of cellular IL-10/IL-12p40 (p<0.01) and IL-10/IL-12p70 (p<0.02) while cellular IFN-gamma levels were reduced (p<0.01). Serum IL-10 levels were decreased in non-responders to therapy based on MRI-defined criteria (p<0.01) but did not change in responders over the course of treatment. In addition, non-responders demonstrated a decrease in serum IL-10/IL-12p70 ratio (p=0.031) and a decrease in cellular IL-12p70 (p<0.02). A decrease in cellular IFN-gamma was observed in responders (p=0.013). This is the first study that compares cytokine changes between the two IFN-beta regimes and demonstrates that serum IL-10 levels decrease in those patients who continue to have active MRI lesions while on interferon-beta therapy.

Clinical response to glatiramer acetate correlates with modulation of IFN-γ and IL-4 expression in multiple sclerosis

Objective To determine whether glatiramer acetate (GA)-induced lymphoproliferation and IFN-γ and IL-4 modulation correlate with the clinical response in multiple sclerosis (MS).

Background GA therapy involves the induction of anti-inflammatory cytokine shifts. However, it is not known whether this response correlates with the clinical outcome.

Methods Thirty-six relapsing-remitting (RR) MS patients were treated with GA for at least two years, and classified clinically as GA-responders (GA-R=22) or hypo/non-responders (GA-HR/NR = 14). Proliferation of peripheral blood mononuclear cells (PBMC) to GA and Tetanus toxoid (TT), as well as IL-4 and IFN-γ ELISPOT, were performed.

Findings There was no difference in PBMC proliferation to GA or TT between GA-R and GA-HR/NR before and during treatment (P>0.05). The mean number of IFN-γ ELISPOTS in unstimulated, TT and anti-CD3/CD28-stimulated PBMC was lower among GA-R (unstimulated: GA-R =10.1±6.21 (n=22) versus GA-HR/NR=17.8±12.7 (n=14), P=0.04; TT-GA-R =12.2±4.06 (n=12) versus GA-HR/NR=26.8±21.0 (n=8), P=0.028; anti-CD-3/CD28 GA-R=217.3±140.4 (n=22) versus GA-HR/NR=368.5±170.1 (n=14), P=0.006). In contrast, the number of IL-4 ELISPOTS remained unchanged in the GA-R group, but was progressively reduced in the GA-HR/NR group during GA therapy (GA-HR/NR IL-4: pre-Rx: 59±34 versus 22±11 at 12 months (n =6), P=0.0429). The IL-4/ IFN-γ ratio in anti-CD3/CD28-stimulated PBMC was significantly higher among GA-R compared to GA-HR/NR (P=0.0474).

Interpretation Lymphoproliferation to GA did not differentiate GA-R from GA-HR/NR. However, reduced IFN-γ expression and stable IL-4 expression in anti-CD3/CD28-stimulated PBMC, and an increased IL-4/IFN-γ ratio was associated with favorable clinical response. More data are needed to validate the prospective use of IL-4/IFN-γ expression in PBMC as a biomarker of clinical response to GA for individual patients. Multiple Sclerosis 2007; 13: 754-762. http://msj.sagepub.com