Genetics of multiple sclerosis

Treatable Ataxias: How to Find the Needle in the Haystack?

Treatable ataxias are a group of ataxic disorders with specific treatments. These disorders include genetic and metabolic disorders, immune-mediated ataxic disorders, and ataxic disorders associated with infectious and parainfectious etiology, vascular causes, toxins and chemicals, and endocrinopathies. This review provides a comprehensive overview of different treatable ataxias. The major metabolic and genetic treatable ataxic disorders include ataxia with vitamin E deficiency, abetalipoproteinemia, cerebrotendinous xanthomatosis, Niemann-Pick disease type C, autosomal recessive cerebellar ataxia due to coenzyme Q10 deficiency, glucose transporter type 1 deficiency, and episodic ataxia type 2. The treatment of these disorders includes the replacement of deficient cofactors and vitamins, dietary modifications, and other specific treatments. Treatable ataxias with immune-mediated etiologies include gluten ataxia, anti-glutamic acid decarboxylase antibody-associated ataxia, steroid-responsive encephalopathy associated with autoimmune thyroiditis, Miller-Fisher syndrome, multiple sclerosis, and paraneoplastic cerebellar degeneration. Although dietary modification with a gluten-free diet is adequate in gluten ataxia, other autoimmune ataxias are managed by short-course steroids, plasma exchange, or immunomodulation. For autoimmune ataxias secondary to malignancy, treatment of tumor can reduce ataxic symptoms. Chronic alcohol consumption, antiepileptics, anticancer drugs, exposure to insecticides, heavy metals, and recreational drugs are potentially avoidable and treatable causes of ataxia. Infective and parainfectious causes of cerebellar ataxias include acute cerebellitis, postinfectious ataxia, Whipple's disease, meningoencephalitis, and progressive multifocal leukoencephalopathy. These disorders are treated with steroids and antibiotics. Recognizing treatable disorders is of paramount importance when dealing with ataxias given that early treatment can prevent permanent neurological sequelae.

[Indications and follow-up for autologous hematopoietic stem cell transplantation in multiple sclerosis: Guidelines from the Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) in association with the Francophone Society of Multiple Sclerosis]

The Francophone Society of Bone Marrow Transplantation and Cellular Therapy (SFGM-TC) organized the 8th allogeneic hematopoietic stem cell transplantation clinical practices harmonization workshop series in September 2017 in Lille, France. In this article we give the indications of autologous stem cell transplantation in multiple sclerosis as well as recommendations regarding post-transplant follow-up of patients under the hospice of the SFGM-TC and the Francophone Society of Multiple Sclerosis.

Mesenchymal Stromal/Stem Cells Do Not Ameliorate Experimental Autoimmune Encephalomyelitis and Are Not Detectable in the Central Nervous System of Transplanted Mice

Mesenchymal stromal/stem cells (MSCs) constitute progenitor cells that can be isolated from different tissues. Based on their immunomodulatory and neuroprotective functions, MSC-based cell-therapy approaches have been suggested to antagonize inflammatory activity and neuronal damage associated with autoimmune disease of the central nervous system (CNS), for example, multiple sclerosis (MS). Intravenous MSC transplantation was reported to ameliorate experimental autoimmune encephalomyelitis (EAE), the murine model of MS, within days after transplantation. However, systemic distribution patterns and fate of MSCs after administration, especially their potential to migrate into inflammatory lesions within the CNS, remain to be elucidated. This question has of recent become particularly important, since therapeutic infusion of MSCs is now being tested in clinical trials with MS-affected patients. Here, we made use of the established EAE mouse model to investigate migration and therapeutic efficacy of murine bone marrow-derived MSCs. Applying a variety of techniques, including magnetic resonance imaging, immunohistochemistry, fluorescence in-situ hybridization, and quantitative polymerase chain reaction we found no evidence for immediate migration of infused MSC into the CNS of treated mice. Moreover, in contrast to other studies, transplanted MSCs did not ameliorate EAE. In conclusion, our data does not provide substantiation for a relevant migration of infused MSCs into the CNS of EAE mice supporting the hypothesis that potential therapeutic efficacy could be based on systemic effects. Evaluation of possible mechanisms underlying the observed discrepancies in MSC treatment outcomes between different EAE models demands further studies.

Variant of multiple sclerosis with dementia and tumefactive demyelinating brain lesions

We describe an unusual clinical and diagnostic feature of a patient with multiple sclerosis (MS). A 25-year-old woman was admitted to the Neurology department (December 2009) with one month history of rapid cognitive deterioration. She had poor cognition, dysphasia, reduction in visual acuity and temporal pallor of the optic discs. She had prolonged latencies of P100 component of visual evoked potentials (VEPs). Magnetic resonance imaging (MRI)-brain showed multifocal large (≥ 3 cm) white-matter hypointense lesions in T1W and hyperintense in T2W and fluid-attenuated inversion recovery images and patchy enhancement. A diagnosis of tumefactive MS was given. She received two consecutive 5-d courses of 1 g daily intravenous methylprednisolone for 2 mo and oral prednisolone in dose of 80 mg twice/daily in between. At the 3^rd month, Mini Mental State Examination and VEPs returned to normal but not the MRI. Patient continued oral steroids after hospital discharge (March 2010) for 9 mo with significant MRI improvement after which tapering of steroids started for a year. The patient refused immunomodulation therapy due to her low socioeconomic status. Neither clinical relapse nor new MRI lesions were observed throughout the next 4 years. In spite of the aggressive course of tumefactive MS variant, good prognosis may be seen in some patients.

Esclerosis múltiple en pacientes pediátricos: fisiopatología, diagnóstico y manejo

ResumenObjetivo: Revisar la literatura disponible sobre esclerosis múltiple en la población pediátrica.Métodos: Revisión sistemática de la literatura encontrada en las bases de datos Scopus y PubMed posterior al año 2000.Resultados y Conclusiones: La Esclerosis Múltiple es una enfermedad con una tasa de incidencia de 2 – 4 / 100.000 habitantes en Colombia, de la cual la población pediátrica representa entre 2,7 – 5% de los casos. Las causas que se han atribuido a la enfermedad son múltiples, incluyendo factores ambientales como infecciones virales o bacterianas, exposición a humo de cigarrillo o deficiencia de vitamina D, entre otras, genéticas e inmunológicas. Su diagnóstico se basa en los hallazgos clínicos e imagenológicos, previa exclusión de enfermedades más comunes. Su tratamiento se divide en tres ejes: el tratamiento de eventos agudos, el tratamiento modificador de la enfermedad y el tratamiento sintomático. Para el primero los medicamentos de primera elección son los corticoides, para el segundo los medicamentos inmunomoduladores como Acetato de Glatiramer y para el tercero se debe realizar un enfoque multidisciplinario. Su pronóstico a largo plazo es variable y depende en alguna medida de la respuesta al tratamiento.

Central nervous system recruitment of effector memory CD8+ T lymphocytes during neuroinflammation is dependent on α4 integrin

Clonally expanded CD8⁺ T lymphocytes are present in multiple sclerosis lesions, as well as in the cerebrospinal fluid of patients with multiple sclerosis. In experimental autoimmune encephalomyelitis, CD8⁺ T lymphocytes are found in spinal cord and brainstem lesions. However, the exact phenotype of central nervous system-infiltrating CD8⁺ T lymphocytes and the mechanism by which these cells cross the blood–brain barrier remain largely unknown. Using cerebrospinal fluid from patients with multiple sclerosis, spinal cord from experimental autoimmune encephalomyelitis and coronavirus-induced encephalitis, we demonstrate that central nervous system-infiltrating CD8⁺ T lymphocytes are mostly of the effector memory phenotype (CD62L⁻ CCR7⁻ granzymeB^hi). We further show that purified human effector memory CD8⁺ T lymphocytes transmigrate more readily across blood-brain barrier-endothelial cells than non-effector memory CD8⁺ T lymphocytes, and that blood-brain barrier endothelium promotes the selective recruitment of effector memory CD8⁺ T lymphocytes. Furthermore, we provide evidence for the recruitment of interferon-γ- and interleukin-17-secreting CD8⁺ T lymphocytes by human and mouse blood-brain barrier endothelium. Finally, we show that in vitro migration of CD8⁺ T lymphocytes across blood-brain barrier-endothelial cells is dependent on α4 integrin, but independent of intercellular adhesion molecule-1/leucocyte function-associated antigen-1, activated leucocyte cell adhesion molecule/CD6 and the chemokine monocyte chemotactic protein-1/CCL2. We also demonstrate that in vivo neutralization of very late antigen-4 restricts central nervous system infiltration of CD8⁺ T lymphocytes in active immunization and adoptive transfer experimental autoimmune encephalomyelitis, and in coronavirus-induced encephalitis. Our study thus demonstrates an active role of the blood-brain barrier in the recruitment of effector memory CD8⁺ T lymphocytes to the CNS compartment and defines α4 integrin as a major contributor of CD8⁺ T lymphocyte entry into the brain.

Pathophysiology of multiple sclerosis and the place of teriflunomide

Significant progress in multiple sclerosis (MS) treatment has been made over the last two decades, including the emergence of disease-modifying therapy (DMT). However, substantial unmet medical need persists and has stimulated the search for new therapeutics. Teriflunomide, one of the several oral DMTs under investigation, is a selective inhibitor of de novo pyrimidine synthesis which exerts a cytostatic effect on proliferating T- and B lymphocytes in the periphery and thus has both antiproliferative and anti-inflammatory properties. Anti-inflammatory effects have been demonstrated in rodent MS models, with reductions in macrophage and B- and T-cell infiltration in the central nervous system and preservation of myelin and oligodendrocytes. Delays in disease onset, reductions in disease relapses and improvements in clinical symptoms were also observed. A proof-of-concept clinical trial in patients with relapsing MS demonstrated that teriflunomide significantly reduced magnetic resonance imaging (MRI) activity and improved clinical endpoints, with both effects maintained with longer-term treatment. Additional studies have shown that teriflunomide can be safely added to beta interferon or glatiramer acetate therapy, with some evidence of additional improvements in MRI disease burden and clinical signs. Teriflunomide has an acceptable and manageable safety and tolerability profile. A large clinical programme is underway to further elucidate the role of teriflunomide in the treatment of MS.

Tumefactive multiple sclerosis: an uncommon diagnostic challenge

OBJECTIVE

This case report describes a rare presentation of multiple sclerosis (MS) that was initially diagnosed as a peripheral nerve lesion in the emergency department.

CLINICAL FEATURES

A 30-year-old woman presented to a chiropractic teaching clinic with a complaint of a sudden right foot drop. Magnetic resonance imaging of the brain revealed a large mass in the left parietal lobe with additional white matter lesions. The mass and smaller lesions were consistent with a rare presentation of demyelinating disease, tumefactive MS.

INTERVENTION AND OUTCOME

The patient was referred to a neurologist for further evaluation and treatment. Her short-term clinical course was punctuated by recurrent myospasms and neurologic deficits.

CONCLUSION

Tumefactive MS may mimic the clinical and magnetic resonance imaging characteristics of glioma or a cerebral abscess. The clinical presentation, pathophysiology, differential diagnosis, role of diagnostic imaging, and treatment options of MS are described. This case report illustrates that the timely diagnosis and optimal treatment of MS require recognition of its varied, sometimes atypical, and often nonspecific clinical and imaging manifestations.

Autologous hematopoietic cell transplantation for multiple sclerosis: a systematic review

BACKGROUND AND OBJECTIVES

The purpose of this systematic review was to evaluate the safety and efficacy of autologous hematopoietic cell transplantation in patients with progressive multiple sclerosis (MS) refractory to conventional medical treatment.

METHODS

Eight case series met our a priori inclusion criteria for the primary outcome of progression-free survival. Individual study quality was rated using an 11-item scale for case series. The strength of the overall body of evidence for each outcome was rated using a system developed by the ECRI Institute. Data from different studies were statistically combined using meta-analysis. An additional six studies were included for a summary of mortality and morbidity.

RESULTS

For secondary progressive MS, immunoablative therapy with autologous bone marrow/peripheral blood stem cell transplantation was associated with higher progression-free survival (up to 3 years following treatment) when using intermediate-intensity conditioning regimens compared with high-intensity conditioning regimens. The evidence was insufficient to determine whether the treatment was effective in patients with other types of MS. Treatment-related mortality was about 2.7%.

CONCLUSIONS

Patients with secondary progressive MS refractory to conventional medical treatment have longer progression-free survival following autologous stem cell transplantation with intermediate-intensity conditioning regimens than with high-intensity conditioning regimens.

Characterization of D6S2806 and D6S2879 short tandem repeat loci in HLA-DRB1 region in Iranian population

Genomewide screen analysis has shown the close association of the human leukocyte antigen (HLA)-DRB1 region with susceptibility to multiple sclerosis and a number of autoimmune diseases. Using bioinformatics software, several potential short tandem repeat (STR) markers have been introduced in this region in the major histocompatibility complex data base (dbMHC). In this study, the identity and characteristics of two putative STR markers, D6S2879 and D6S2806, in this region were examined in Iranian population. The loci were genotyped in 85 individuals using polymerase chain reaction followed by polyacrylamide gel electrophoresis and sequencing. Analysis of the allelic frequency showed the presence of six and four alleles for D6S2806 and D6S2879, respectively. Analysis of deviations from Hardy-Weinberg equilibrium (HWE) showed that D6S2806 was in equilibrium (P > 0.05). However, the D6S2879 locus showed a significant deviation from HWE (P < 0.05). Therefore, the D6S2806 locus could be suggested as a marker for linkage analysis and disease-susceptibility investigations in the MHC-DRB1 gene region.

A computational analysis of protein-protein interaction networks in neurodegenerative diseases

BACKGROUND

Recent developments have meant that network theory is making an important contribution to the topological study of biological networks, such as protein-protein interaction (PPI) networks. The identification of differentially expressed genes in DNA array experiments is a source of information regarding the molecular pathways involved in disease. Thus, considering PPI analysis and gene expression studies together may provide a better understanding of multifactorial neurodegenerative diseases such as Multiple Sclerosis (MS) and Alzheimer disease (AD). The aim of this study was to assess whether the parameters of degree and betweenness, two fundamental measures in network theory, are properties that differentiate between implicated (seed-proteins) and non-implicated nodes (neighbors) in MS and AD. We used experimentally validated PPI information to obtain the neighbors for each seed group and we studied these parameters in four networks: MS-blood network; MS-brain network; AD-blood network; and AD-brain network.

RESULTS

Specific features of seed-proteins were revealed, whereby they displayed a lower average degree in both diseases and tissues, and a higher betweenness in AD-brain and MS-blood networks. Additionally, the heterogeneity of the processes involved indicate that these findings are not pathway specific but rather that they are spread over different pathways.

CONCLUSION

Our findings show differential centrality properties of proteins whose gene expression is impaired in neurodegenerative diseases.

Preliminary evidences of a NOS2A protective effect from Relapsing–Remitting Multiple Sclerosis

The gene encoding the inducible form of Nitric Oxide Synthase (NOS2A) has been considered with interest in the evaluation of the genetic predisposition to Multiple Sclerosis (MS). The aim of the present study was to address the possible contribution of two microsatellites repeats of the NOS2A promoter region - (CCTTT)(n) and (AAAT)(n) - to MS susceptibility. One hundred and thirteen Italian patients with clinically definite RRMS and 237 age and sex matched healthy controls from Calabria (South Italy) were studied. The distribution analysis of the markers frequencies showed that the (CCTTT)(14) allele was found in 11.5% of the RRMS patients and in 25.3% of the healthy subjects, with a statistically significant difference (chi(2)=8.843, p=0.003). This data seems to confer a significant protection against MS (OR=0.348; 95% CI=0.174-0.693, corrected for age and gender). No association with MS susceptibility was observed for the bi-allelic (AAAT)(n) microsatellite. In conclusion, we found that the NOS2A (CCTTT)(14) allele was detected more frequently in the control group than in the RRMS patients, thus confirming the scientific interest on this marker.

Multiple sclerosis: a complicated picture of autoimmunity

Understanding of autoimmune diseases, including multiple sclerosis, has expanded considerably in recent years. New insights have been provided by not only animal models but also studies of patients, often in conjunction with experimental therapies. It is accepted that autoimmune T cells mediate the early steps of new multiple sclerosis lesions, and although uncertainties remain about the specific targets of autoreactive T cells, several studies indicate myelin antigens. Recent findings obtained with both animal models and patients with multiple sclerosis indicate involvement of a T helper cell with a T(H)-17 phenotype, in contrast to previous data indicating that T helper type 1 cells are critical. Evidence has also been presented for CD8(+) and regulatory T cell populations, although their involvement remains to be established. Despite evidence supporting the idea that autoreactive T cells are involved in disease induction, cells of myeloid lineage, antibodies and complement as well as processes intrinsic to the central nervous system seem to determine the effector stages of tissue damage. Careful analysis of the alterations in immune processes should further advance knowledge of the relationship between the inflammatory component of this disease and the more diffuse degeneration of progressive multiple sclerosis.

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.

How to successfully apply animal studies in experimental allergic encephalomyelitis to research on multiple sclerosis

In their Point of View entitled "Experimental Allergic Encephalomyelitis: A Misleading Model of Multiple Sclerosis," Sriram and Steiner(1) wrote, "The most disappointing aspect of EAE [experimental allergic encephalomyelitis] as a potential model for MS is its almost total inability to point toward a meaningful therapy or therapeutic approach for MS." Actually, EAE has led directly to the development of three therapies approved for use in multiple sclerosis (MS): glatiramer acetate, mitoxantrone, and natalizumab. Several new approaches to MS are in clinical trials based on positive indications in preclinical work relying on EAE. New clues to the pathogenesis of MS and new potential surrogate markers for MS are shown from research involving EAE when it is critically coupled with actual findings in MS. There are pitfalls in overreliance on the EAE model, or on any animal model for any human disease. Nevertheless, over the past 73 years, the EAE model has proved itself remarkably useful for aiding research on MS.

Effects of the major histocompatibility complex loci and T-cell receptor beta-chain repertoire on Theiler's virus-induced demyelinating disease

We have investigated the potential effects of H-2 and T-cell receptor (TCR) V beta family genes on induction of T-cell immunity and susceptibility to virally induced demyelinating disease by using BALB.S (H-2K(s)A(s)D(s)) and BALB.S 3 R (H-2K(s)A(s)D(d)/L(d)) mice. These parameters were compared with those of highly susceptible SJL/J (H-2K(s)A(s)D(s)) mice that contain only one-half of TCR V beta family genes compared with the above-mentioned strains. Our results demonstrate that BALB.S but not BALB.S 3 R mice are susceptible similar to SJL/J mice. Although the level of CD4(+) T-cell infiltration to the CNS was elevated in susceptible mice, virus-specific immune responses restricted with H-2(s) were similar in these mice. No preferential use of V beta families associated with differences in the major histocompatibility complex (MHC) components was apparent. However, the pattern and sequence of CDR 3 distribution shows T-cell clonal accumulation in the CNS associated with the H-2 components. Further anti-CD8 antibody treatment of resistant BALB.S 3 R mice abrogated resistance to demyelinating disease, indicating that CD8(+) T cells restricted with H-2D(d)/L(d) are most likely to exert resistance in BALB.S 3 R mice. These studies indicated that TCR V beta and MHC class II genes are the secondary to a particular MHC class I gene expression in susceptibility to virally induced demyelinating disease.