Review of the novelties presented at the 28th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) (III).

The most significant data presented at the 28th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS), held in France in October 2012, have been summarised in the fifth edition of the Post-ECTRIMS Experts Meeting, held in Madrid in October 2012. This led to the drafting of this review, which has been published in three parts. This third part of the Post-ECTRIMS review presents the findings from the latest studies conducted with disease-modifying treatments, more specifically with glatiramer acetate, laquinimod, ponesimod, BG-12, teriflunomide, daclizumab, natalizumab and secukinumab (AIN457). Likewise, we also address the reasons that justify the search for innovative treatments for multiple sclerosis, with antigen-specific therapy, cell therapy and therapy aimed at promoting remyelination being highlighted among other future therapeutic strategies. Access to new pharmacological agents and the complexity of the therapy of multiple sclerosis in the future will require new design strategies and directions in clinical trials, including the use of surrogate markers, new statistical applications, superiority, inferiority or equivalence clinical trials and adaptable designs.

TITLE: Revision de las novedades presentadas en el XXVIII Congreso del Comite Europeo para el Tratamiento e Investigacion en Esclerosis Multiple (ECTRIMS) (III).Los datos mas relevantes presentados en la XXVIII edicion del Congreso del Comite Europeo para el Tratamiento e Investigacion en Esclerosis Multiple (ECTRIMS), celebrado en octubre de 2012 en Francia, han sido resumidos en la quinta edicion de la Reunion de Expertos Post-ECTRIMS celebrada en Madrid en octubre de 2012, fruto de la cual nace esta revision que se publica en tres partes. Esta tercera parte de la revision Post-ECTRIMS expone los resultados de los ultimos estudios realizados con los tratamientos modificadores de la enfermedad, concretamente con acetato de glatiramero, laquinimod, ponesimod, BG-12, teriflunomida, daclizumab, natalizumab y secukinumab (AIN457). Asimismo, se abordan las razones que justifican la busqueda de tratamientos innovadores para la esclerosis multiple, destacando la terapia antigenoespecifica, la terapia celular y la terapia dirigida a promover la remielinizacion entre las futuras estrategias terapeuticas. La disponibilidad de nuevos farmacos y la complejidad de la futura terapia de la esclerosis multiple necesitan nuevas direcciones y estrategias de diseño en los ensayos clinicos, entre ellas el uso de marcadores subrogados, nuevas aplicaciones estadisticas, ensayos clinicos de superioridad, inferioridad o equivalencia, y diseños adaptables.

Review of the novelties presented at the 28th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) (I).

The most relevant data presented at the 28th edition of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS), held in October 2012 in France, have been summarized in the fifth edition of the Post-ECTRIMS Expert Meeting held in Madrid in October 2012. The present review summarizes the views and results of the meeting and is being published in three parts. This first part of the Post-ECTRIMS review addresses the incidence and prevalence of multiple sclerosis (MS), which has increased at the global level, largely due to the increased incidence in women because the risk of developing the disease is increased in females, with minimal concurrent effect on the progression of MS. Sexual dimorphism is evident in MS, and all evidence points to an interaction between hormonal, genetic, and environmental factors. The paediatric population represents an ideal group to study susceptibility factors to the disease, which is why collaborative studies designed to increase the patient samples are being considered, given its low prevalence. In this review, inflammatory and neurodegenerative phenomena involved in the pathogenesis of the disease and that have a cause-and-effect or shared relationship with the disease are being discussed. Current hypotheses suggest a phenomenon of compartmentalization, presumably inaccessible to current immunomodulatory therapy. Among the possible mechanisms involved in these processes of inflammation and demyelination, the role of Th17 cells, mitochondrial dysfunction, early disruption of astrocytic processes, and chronic hypoxia are discussed.

TITLE: Revision de las novedades presentadas en el XXVIII Congreso del Comite Europeo para el Tratamiento e Investigacion en Esclerosis Multiple (ECTRIMS) (I).Los datos mas relevantes presentados en la XXVIII edicion del Congreso del Comite Europeo para el Tratamiento e Investigacion en Esclerosis Multiple (ECTRIMS), celebrado en octubre de 2012 en Francia, se han resumido en la quinta edicion de la Reunion de Expertos Post-ECTRIMS celebrada en Madrid en octubre de 2012, fruto de la cual nace esta revision, que se publica en tres partes. Esta primera parte de la revision Post-ECTRIMS aborda la incidencia y prevalencia de la esclerosis multiple (EM), que, en el ambito mundial, ha aumentado a expensas de las mujeres, ya que el sexo femenino aumenta el riesgo de desarrollar la enfermedad, aunque no afecta de forma negativa a su evolucion. El dimorfismo sexual en la EM es evidente, y todo apunta a una interaccion entre factores hormonales, geneticos y medioambientales. La poblacion pediatrica representa un grupo idoneo para el estudio de factores de susceptibilidad a la enfermedad, razon por la que se estan planteando estudios colaborativos ideados para aumentar la muestra de pacientes, dada su baja prevalencia. En esta revision se discute sobre los fenomenos inflamatorios y de neurodegeneracion que intervienen en la patogenia de la enfermedad, y que probablemente esten relacionados, bien de forma compartida o como causa efecto. Las hipotesis actuales apuntan a un fenomeno de compartimentacion presumiblemente inaccesible a la terapia inmunomoduladora actual. Entre los posibles mecanismos involucrados en estos procesos de inflamacion y desmielinizacion se discute el papel de las celulas Th17, disfuncion mitocondrial, disrupcion precoz de procesos astrocitarios e hipoxia cronica.

Anti-JCV antibodies detection and JCV DNA levels in PBMC, serum and urine in a cohort of Spanish Multiple Sclerosis patients treated with natalizumab.

One of the most effective multiple sclerosis (MS) treatment is natalizumab. Nevertheless, it has been associated with an increased risk of progressive multifocal leukoencephalopathy (PML) caused by the JC virus (JCV). Our main objective was to assess the utility of testing JCV-DNA, apart from anti-JCV antibodies, to determine which natalizumab-treated MS patients has been previously in contact with the virus. For this purpose, 138 MS natalizumab/non-natalizumab treated patients participated in several studies. Cross-sectional study (CS): association of several epidemiological variables with anti-JCV antibodies and JCV-DNA levels in PBMC/serum/urine. First longitudinal study (A): evaluation of JCV-DNA prevalence in urine throughout the treatment. Second longitudinal study (B): simultaneous assessment of antibodies and viral DNA levels in PBMC/serum/urine at two time points. CS: The seropositivity rate for anti-JCV antibodies (62.3 %) and JCV prevalence in urine (59.4 %) were similar; although 26 % of our population was positive only using one of the two techniques. A: The viral prevalence in urine seemed to increase between the baseline visit and the others (Baseline-Visit/V18months, p = 0.006). B: Our rate of positive antibody seroconversion was 36 %. Nearly all patients with detectable JCV-DNA levels in PBMC excreted the virus intermittently in urine; while our PML case, positive in PBMC and serum samples 2 month before the PML, excreted JCV permanently. In conclusion, the determination of JCV DNA levels in urine could be complementary to anti-JCV antibodies for identifying MS patients who has been infected by the JCV. Further research would be necessary to understand the different JCV excretion profiles in urine.

The DNA copy number of human endogenous retrovirus-W (MSRV-type) is increased in multiple sclerosis patients and is influenced by gender and disease severity.

BACKGROUND: Multiple sclerosis is an autoimmune disease more prevalent in women than in men. Multiple Sclerosis Associated Retrovirus element (MSRV) is a member of type-W endogenous retrovirus family (HERV-W), known to be associated to MS. Most HERVs are unable to replicate but MSRV expression associated with reverse-transcriptase activity in MS would explain reported DNA copy number increase in MS patients. A potential link between HERV-W copies on chromosome X and gender differential prevalence has been suggested. The present study addresses MSRV-type DNA load in relation with the gender differences and clinical status in MS and healthy controls. RESULTS: 178 MS patients (62.9% women) and 124 controls (56.5% women) were included. MSRV env load (copies/pg of DNA) was analyzed by real time qPCR with specific primers and probe for its env gene, in DNA from peripheral blood mononuclear cells (PBMCs). MSRV load was more elevated in MS patients than in controls (p = 4.15e-7). MS women presented higher MSRV load than control women (p = 0.009) and MS men also had higher load than control men (p = 2.77e-6). Besides, women had higher levels than men, both among patients (p = 0.007) and controls (p = 1.24e-6). Concordantly, EDSS and MSSS scores were higher among female patients with an elevated MSRV load (p = 0.03 and p = 0.04, respectively). CONCLUSIONS: MSRV increases its copy number in PBMC of MS patients and particularly in women with high clinical scores. This may explain causes underlying the higher prevalence of MS in women. The association with the clinical severity calls for further investigations on MSRV load in PBMCs as a biomarker for MS.

MHC2TA mRNA levels and human herpesvirus 6 in multiple sclerosis patients treated with interferon beta along two-year follow-up.

BACKGROUND: In previous studies we found that MHC2TA +1614 genotype frequency was very different when MS patients with and without human herpesvirus 6 (HHV-6) in serum samples were compared; a different clinical behavior was also described. The purpose of the study was: 1. To evaluate if MHC2TA expression in MS patients was influenced by interferon beta (IFN-beta) treatment. 2. To study MHC2TA expression in MS patients with and without minor allele C. 3. To analyze the relation between MHC2TA mRNA levels and HHV-6 active infection in MS patients. METHODS: Blood and serum samples of 154 MS patients were collected in five programmed visits: basal (prior to beginning IFN-beta treatment), six, twelve, eighteen and twenty-four months later. HHV-6 in serum and MHC2TA mRNA levels were evaluated by PCR and RT-PCR, respectively. Neutralizing antibodies (NAbs) against IFN-beta were analyzed by the cytopathic effect assay. RESULTS: We found that MHC2TA mRNA levels were significantly lower among MS patients with HHV-6 active infection at the basal visit (without treatment) than in those MS patients without HHV-6 active infection at the basal visit (p = 0.012); in all the positive samples we only found variant A. Furthermore, 58/99 (58.6%) MS patients without HHV-6 along the five programmed visits and an increase of MHC2TA expression after two-years of IFN-beta treatment were clinical responders vs. 5/21 (23.8%) among those MS patients with HHV-6 and a decrease of MHC2TA mRNA levels along the two-years with IFN-beta treatment (p = 0.004); no differences were found between patients with and without NAbs. CONCLUSIONS: MHC2TA mRNA levels could be decreased by the active replication of HHV-6; the absence of HHV-6 in serum and the increase of MHC2TA expression could be further studied as markers of good clinical response to IFN-beta treatment.

Review of the novelties presented at the 27th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) (II).

The new insights presented at the 5th Joint Triennial Congress of the European and Americas Committees on Treatment and Research in Multiple Sclerosis (ECTRIMS and ACTRIMS) held in Amsterdam, the Netherlands, 19-22 October 2011, have been summarized at the fourth edition of Post-ECTRIMS meeting held in Madrid in November 2011. Regional grey-matter atrophy is more sensitive to cognitive impairment than global grey-matter atrophy measures. In patients with clinically isolated syndrome cognitive impairment does not predict conversion to multiple sclerosis (MS) after 5-years of follow-up. Focusing on central nervous system plasticity and functional reorganization in MS, an early intervention can improve clinical aspects and enhances brain plasticity. Preservation of a potential for plasticity provides a rationale for rehabilitation interventions even in later stages of disease. Therapeutical strategies have focused on stem cell-mediated remyelination and immunomodulation functions, on cellular infiltration into the brain, and on new ways for immuno-modulation for the development of future therapies in MS. Encouraging findings from clinical trials with current and emerging disease-modifying therapy being developed was also a key theme at this edition. Positive results have been reported for rituximab, ocrelizumab, ofatumumab, daclizumab, alemtuzumab, teriflunomide, BG-12, and laquinimod, including a favorable safety profile. Since armamentarium for the treatment of MS is fast increasing, concerns exist about the risk of severe adverse events with their use. This aspect reinforces the importance of disease registries as a proactive tool for monitoring drug safety in the post-approval setting.

Review of the novelties presented at the 27th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) (I).

The new insights presented at the 5th Joint Triennial Congress of the European and Americas Committees on Treatment and Research in Multiple Sclerosis (ECTRIMS and ACTRIMS) held in Amsterdam, the Netherlands, 19-22 October 2011, have been summarized at the fourth edition of Post-ECTRIMS meeting held in Madrid in November 2011. Further evidence from epidemiological studies yield a possible relationship between nutrition and alterations of the microbiota that may result in the development of multiple sclerosis (MS) and that may trigger the exacerbation of disease symptoms. Also show the magnitude of impact of comorbidities in multiple sclerosis course as well as the impact of early identification and management. Review of current data on chronic cerebrospinal venous insufficiency and MS sclerosis concludes that there is no role of chronic cerebrospinal venous insufficiency in either multiple sclerosis risk or MS severity. New diagnostic criteria for MS have simplified requirements for demonstrating dissemination of lesions in time. High-field magnetic resonance imaging improves cortical visualization and become a promising tool to detect remyelinization and cortical and medullary lesions, and optical coherence tomography is established as a powerful tool for neuroprotection trials. Diffuse meningeal inflammation through B-cell follicle-like structures is associated with cortical pathology and an accelerated clinical course in secondary progressive MS sclerosis. Systemic inflammation may contribute to neurodegeneration processes in MS, and with regard to grey matter damage recent findings conclude that occurs early in disease course, and correlates with future MS-related disability.

Herpesvirus active replication in multiple sclerosis: a genetic control?

Although the etiology of multiple sclerosis (MS) is unknown, it is generally believed that genetic, immunologic, and environmental factors are involved. The objectives of this study were: 1. to analyze if a genetic control could explain why HHV-6 would be able to actively replicate in a subset of MS patients but not in controls; 2. to study if MS patients with HHV-6 active replication are clinically different from those without HHV-6 active replication. A total of 195 MS patients and 195 controls were analyzed for two SNPs at the MHC2TA locus and two SNPs at the CD46 locus. Furthermore, the MS cohort was analyzed by PCR for the detection of HHV-6 genomes in five serum samples collected every six months along two-year follow-up. We found that 59/195 (30.2%) MS patients had at least one HHV-6 positive serum sample. No statistical significant difference was found for the two genes when the comparison was made between MS patients and controls; however, a statistical significance was found for the two polymorphisms of MHC2TA when we compared MS patients with active replication and controls (p=0.0000004 for rs4774C and p=0.011 for rs3087456G). Furthermore, increased significant differences were found for MHC2TA and CD46 when we compared interferon beta responders and non-responders within MS patients. In conclusion, we describe a gene-environment interaction in MS patients between HHV-6 and MHC2TA and CD46 that should be further studied to clarify if that interaction could be a genetic control. The results show that MS patients without HHV-6 active replication are better responders to interferon beta treatment than those with HHV-6 active replication.

[Review of the novelties presented at the 26th Congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) (I)]. / Revision de las novedades presentadas en el XXVI Congreso del Comite Europeo para el Tratamiento e Investigacion en Esclerosis Multiple (ECTRIMS) (I).

The new insights presented at European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS), held in the city of Gothenburg, Sweden, in October 2010, have been summarized at the third edition of Post-ECTRIMS meeting held in Madrid in November 2010. The age is an important factor related to the course and prognosis of multiple sclerosis (MS). The evolution to progressive disease persists more than 50 years after diagnosis of MS and a reduction in the delay of diagnosis has been detected. Several strategies have been proposed in order to improve the efficacy of magnetic resonance regarding prognosis and course of disease. The studies presented at the Congress reflect the influence of gender on course and severity of disease symptoms, showing an increase of worldwide prevalence of MS in women. Neuroprotective action of estrogen receptor beta has been reported. The genome wide association studies have allowed investigators to identify numerous susceptible alleles. In this regard, HLA class II genes, seems to contribute to genetic risk for developing neutralizing antibodies against beta-interferon. Vitamin D deficiency and Epstein-Barr virus have been highlighted as risk factors for MS in the reported findings. On the subject of the ongoing controversy regarding the role of inflammation and degeneration in MS, several arguments have been found to support the role of CNS autoimmunity to explain the presence of inflammatory phenomenon. The available data hold the potential therapeutic role of mesenchymal cells given the involvement of these stem cells in CNS repair.

The CAREQOL-MS was a useful instrument to measure caregiver quality of life in multiple sclerosis.

OBJECTIVE: To develop and test the first specific instrument for assessing caregiver health-related quality of life (HRQOL) in multiple sclerosis (MS) (CAREQOL-MS). STUDY DESIGN AND SETTING: Questionnaire items were derived from a literature review and the views of patients, caregivers, and experts. Instrument was reduced after the analyses of caregivers' interviews and experts' opinions. CAREQOL-MS psychometric properties were assessed in 276 MS caregivers. RESULTS: The final version consisted of 24 items (five subscales) and was free of floor or ceiling effects. For subscales, the Cronbach's alpha coefficient ranged from 0.75 to 0.90. The item-total correlation was 0.62-0.74 for subscale I (physical burden/global health); 0.56-0.74 for subscale II (social impact); 0.52-0.62 for subscale III (emotional impact), and 0.58-0.65 for subscale IV (need of help); subscale V (emotional reactions) had only two items. The intraclass correlation coefficient (0.96 for the total score; 0.75-0.95 for subscales) suggested satisfactory reproducibility. Association was close between CAREQOL-MS subscales and the Zarit burden interview and moderate with short form 36 mental/physical components. CAREQOL-MS subscales scores significantly increased (worse HRQOL) with increasing caregivers' age and Expanded Disability Status Scale. The standard error of the measurement ranged from 0.91 to 2.43 for subscales. CONCLUSIONS: Our results provided initial evidence of the usefulness and satisfactory psychometric properties of the CAREQOL-MS.

CD46 in a Spanish cohort of multiple sclerosis patients: genetics, mRNA expression and response to interferon-beta treatment.

BACKGROUND: In a prior study of our group we found an up-regulation of CD46 expression in a cohort of Spanish multiple sclerosis (MS) patients. OBJECTIVE: To evaluate the potential role of CD46 in the response to interferon-beta treatment in MS patients through the analysis of five tagging single nucleotide polymorphisms (SNPs) and measurement of mRNA. METHODS: A total of 406 MS patients and 513 control patients were analysed for five SNPs at the CD46 locus. Furthermore, 163 MS patients and 163 matched control patients were analysed by RT-PCR for the CD46 mRNA expression in three blood samples (basal, and at 6 and 12 months of interferon-beta treatment) collected in the course of a 1-year follow-up. RESULTS: Two genotypes of rs2724385 polymorphism (AT and TT) could be markers of response to interferon-beta therapy in MS patients (p=0.007 and p=0.006, respectively). Furthermore, the frequency of interferon-beta responders was 44.4% (32/72) in MS patients with an increased CD46 mRNA expression, vs. 65.9% (60/91) in patients with a decreased CD46 mRNA expression (p=0.006). CONCLUSION: The present study shows that CD46 could be associated with the response to interferon-beta therapy; however, the genetic results should be replicated in an independent cohort and further studies are needed to confirm the role of CD46.

Polymorphisms in the IL2, IL2RA and IL2RB genes in multiple sclerosis risk.

Interleukin (IL)-2/IL-2R signalling promotes proliferation and survival of activated T cells and has an essential non-redundant role in the production of regulatory T cells. Associations with different autoimmune diseases of polymorphisms in a linkage disequilibrium block in which the IL2/IL21 genes map (4q27), and also in genes encoding the IL2RA and IL2RB subunits (located in 10p15 and 22q13, respectively), were identified through genome-wide studies. Polymorphisms in these three genes were studied in 430 multiple sclerosis (MS) patients and in 550 ethnically matched controls from Madrid (Spain). Replication and meta-analysis with results from an independent cohort of 771 MS patients and 759 controls from Andalucía (Spain) confirmed the association of polymorphisms in the IL2RA gene (P(Mantel-Haenszel,) odds ratio (OR)(M-H) (95% confidence interval, CI) for rs2104286: 0.0001, 0.75 (0.65-0.87); for rs11594656/rs35285258: 0.004, 1.19 (1.06-1.34); for rs41295061: 0.03, 0.77 (0.60-0.98)); showed a trend for association of the IL2/IL21 rs6822844 (P(M-H)=0.07, OR(M-H) (95% CI)=0.86 (0.73-1.01)), but did not corroborate the association for IL2RB. Regression analyses of the combined Spanish cohort revealed the independence of two IL2RA association signals: rs2104286 and rs11594656/rs35285258. The relevant role of the IL2RA gene on MS susceptibility adds support to its common effect on autoimmune risk and the suggestive association of IL2/IL21 warrants further investigation.

IFNbeta-1a therapy for multiple sclerosis expands regulatory CD8+ T cells and decreases memory CD8+ subset: a longitudinal 1-year study.

The beneficial effects of interferon beta-1a (IFNbeta-1a) in multiple sclerosis (MS) remain only partially understood. CD8(+) T cells are key cells in MS pathogenesis that contribute to axonal damage in MS, whereas CD4(+) regulatory T cells (T(Reg)) and CD8(+) regulatory/suppressor T cells (Ts) play an important role in protecting against subsequent MS activity. We analysed ex vivo changes on T(Reg) and on the different subsets of CD4(+) and CD8(+) T lymphocytes, before IFNbeta-1a (Rebif) therapy and at 3, 6, and 12 months after treatment, in 23 MS patients and in 26 healthy controls. IFNbeta-1a significantly increased the proportions of CD4(+) T(Reg) and regulatory CD8(+) T cells (Tr). Memory CD8(+) T cells were significantly decreased after 1 year of treatment, maybe reflecting down-regulation of abnormally persistent systemic activation in MS patients. After 1 year of IFNbeta-1a, a direct correlation was observed between plasmacytoid dendritic cells and effector CD8(+) T cells.

Clinical response to interferon-beta-1a may be linked to low baseline circulating BDCA1 myeloid dendritic cells Differential role of circulating dendritic cells and CD4+ regulatory T-cells in relapsing-remitting multiple sclerosis: a 1-year longitudinal study.

Many variables with association with better response to interferon-beta-1a (IFNbeta-1a) have been described, but none has yet been shown to be predictive of clinical response. In this real-life observational 1-year longitudinal study of 23 relapsing-remitting multiple sclerosis (RRMS) patients treated with subcutaneous IFNbeta-1a, we have shown a lower proportion of circulating myeloid dendritic cells (mDCs) than in healthy controls at baseline. Both univariate (Kaplan-Meier) and multivariate (Cox regression) analyses were conducted to determine which variables (age, sex, baseline EDSS, MS relapse rates 1 year and 2 years before initiating IFNbeta-1a, mDCs and plasmacytoid (pDCs) subsets, activated and regulatory CD4(+) T-cells (T(Reg))) were associated with clinical response to IFNbeta-1a. During 1 year of treatment, we observed a shift towards lower proportions of CD123(+) pDCs expression and higher numbers and function of the T(Reg). Univariate analysis disclosed that MS activity was significantly associated with baseline BDCA1(+) mDCs below < or = 0.4% (p<0.0025). Cox model analysis revealed that baseline BDCA1(+) mDCs was the most closely associated factor with MS activity on IFN treatment during the 1-year follow-up (p<0.01). A better understanding of the rules that govern the T(Reg)-DC relationship will enable scientists to better manage the immune response in MS patients.

IFIH1-GCA-KCNH7 locus: influence on multiple sclerosis risk.

A recent genome-wide scan of nonsynonymous SNPs and ulterior validation in case-control and family analyses evidenced a susceptibility locus for type 1 diabetes (T1D) on chromosome 2q24.3. We aimed at testing the effect of this locus in other autoimmune diseases with complex genetic background, such as multiple sclerosis (MS). Four SNPs along the locus, rs13422767, rs2111485, rs1990760 and rs2068330, were genotyped using TaqMan MGB chemistry in 311 T1D and 412 MS patients and 535 ethnically matched healthy controls. The previously reported association of this locus was found for the first time in MS (rs2068330, G vs C: P=0.001; OR (95% CI)=0.73 (0.6-0.88)) and a trend for replication was observed in our Spanish diabetic cohort. Therefore, genes included in this locus - IFIH1 interferon induced helicase, GCA grancalcin or the potassium channel KCNH7 - are potential candidates implicated in the pathogenesis of these autoimmune diseases, although strong linkage disequilibrium in the region hampered further localization of the etiologic gene.

Interferon beta treatment: bioavailability and antiviral activity in multiple sclerosis patients.

Viral infections have been appointed as the main component of environmental susceptibility to multiple sclerosis (MS). Interferon beta is an immunomudulatory treatment that is able to modify the natural course of the disease; nonetheless, its mechanism of action in not well established yet. The objectives of the present study were (1) to evaluate the bioavailability of interferon beta through the measurement of the expression of myxovirus resistance protein (MxA), metalloproteinase 9 (MMP-9), and its inhibitor (TIMP-1); (2) to analyze its antiviral efficiency through the measurement of human herpesvirus-6 (HHV-6) prevalence; and (3) to correlate both parameters (bioavailability and antiviral efficiency) with the relapse rate in multiple sclerosis (MS) patients treated with interferon beta. Pairs of blood and serum samples were collected from 54 MS patients during five visits in 1 year: one before the start of the treatment and four during interferon beta treatment. Expression of MxA, MMP-9, and TIMP-1 was analyzed by quatitative real-time polymerase chain reaction (qRT-PCR) and HHV-6 genomes were detected by qPCR. The results showed a correlation between MxA and relapse rate (P = .014). MMP-9/TIMP-1 ratio was increased among the patients with relapses, and decreased among the relapse-free patients, although differences were not statistically significant. Furthermore, our results suggest a possible role for HHV-6 in MS, because 42.8% of patients with viral reactivations experienced at least one relapse versus 22.5% of patients without viral reactivations. Lastly, regarding the antiviral effectiveness of the interferon beta, the HHV-6 prevalence decreased from 58% to 36% in PBMCs and from 18.5% to 12.2% in sera; furthermore, a good correlation with the bioavailability of interferon beta was found, because patients with a decrease in HHV-6 prevalence had higher levels of MxA (P = .046, at the third month).

TLR4 haplotypes in multiple sclerosis: a case-control study in the Spanish population.

Our aim in the present study is to evaluate the variation present in the TLR4 gene and its relationship with multiple sclerosis susceptibility in the Spanish population. Three hundred and sixty-two multiple sclerosis patients and 467 healthy controls from the Spanish population were included in the present study. Twelve single nucleotide polymorphisms (SNPs) were selected, and analyzed by the TaqMan technique. No statistically significant differences for any polymorphism or haplotypes were observed when patients were compared with controls. In conclusion, TLR4 does not play a major role in the predisposition to suffer from multiple sclerosis in our population.

Environment-gene interaction in multiple sclerosis: human herpesvirus 6 and MHC2TA.

Multiple sclerosis (MS) is an inflammatory disorder affecting the central nervous system, in which both genetic and environmental factors interact. Among these environmental contributors, herpesvirus has been proposed as an important etiologic factor. CIITA is a transcription factor controlling the expression of MHC class II genes, the main genetic determinants of MS susceptibility. This gene has been described as a target of the immunoevasive strategies, and it is therefore an attractive candidate gene to be at the genetic-viral crossroads. Two polymorphisms in MHC2TA gene (rs4,774G/C and rs3,087,456A/G) were studied in two groups: one in 22 multiple sclerosis patients with active human herpes virus 6 (HHV-6A) replication (HHV-6A-positive), and the other of 77 patients with no detectable HHV-6A active infection (HHV-6A-negative); a Spanish healthy control group (n = 520) was also included as external control. An association of the rs4,774C allele with the HHV-6A-positive group was found when compared with the HHV-6A-negative (47.7% vs 18.8%, p = 0.0001; odds ratio = 3.94) and also with the control group (47.7% vs 25.5%, p = 0.001, odds ratio = 2.67). No significant differences were observed between HHV-6A-negative subjects and healthy controls. Our data suggest that a strong gene-environment interaction occurs between HHV-6A active replication and MHC2TA rs4,774C or another polymorphism in tight linkage disequilibrium with it. Besides, this report indicates that when patients are grouped based upon a well-defined molecular event, complex diseases may reveal themselves as being constituted by distinct entities in which some genes may have a strong influence.

FcRL3 and multiple sclerosis pathogenesis: role in autoimmunity?

BACKGROUND AND AIMS: A functional promoter polymorphism in the FcRL3 gene, -169 T/C, has been shown to regulate gene expression and to play a role in several autoimmune diseases. We aimed at testing for the first time whether this gene was involved in multiple sclerosis (MS) pathogenesis. METHODS: Case-control study performed with 400 Spanish MS patients and 508 healthy subjects. Genotyping of -169 T/C and -110 G/A was ascertained by using TaqMan MGB chemistry following manufacturer suggestions (Applied Biosystems, CA, USA). RESULTS: As previously seen for other autoimmune diseases, a significant difference was observed in the distribution of -169 T/C FcRL3 genotypes between MS patients and healthy controls (p = 0.03; chi(2) = 6.99). The -169 T allele, recently associated with increased susceptibility to Addison's disease, showed a parallel effect in MS [(TT+TC) vs. CC: p = 0.013; OR = 1.55 (1.08-2.54)]. CONCLUSIONS: An increased susceptibility associated to the -169 T allele was found when MS patients and controls were compared, supporting the role of the FcRL3 locus in MS predisposition and therefore extending the evidence of its general influence on autoimmunity.

Human herpesvirus-6 and multiple sclerosis: relapsing-remitting versus secondary progressive.

Recently, it has been suggested that human herpesvirus-6 (HHV-6) may play a role in the pathogenesis of relapsing-remitting multiple sclerosis (RRMS), but there is not enough information related to the role of HHV-6 in secondary-progressive MS (SPMS). To address this question, we evaluated HHV-6 prevalence, active viral replication and viral load measured by quantitative real-time PCR, in DNA and mRNA extracted from peripheral blood mononuclear cells (PBMCs) and DNA extracted from serum; the samples were collected from 31 SPMS and 31 RRMS patients in a one-year follow-up study, and sex- and age-matched controls. The results were as follows: i) We found a statistical significant difference in HHV-6 DNA prevalences between RRMS and SPMS patients in: DNA extracted from PBMCs (P=0.027), DNA extracted from serum (P=0.010) and mRNA extracted from PBMCs (P=0.010). When we compared HHV-6 prevalences from RRMS patients in relapse and in remission with those from SPMS patients, we only achieved a statistical significance for the relapses (P=0.003 in DNA from PBMCs, and P<0.001 in DNA from serum samples and mRNA from PBMCs). ii) We only found HHV-6 variant A among HHV-6 positive samples in serum. iii) We did not find any difference in HHV-6 viral loads. These results suggest that HHV-6A does not play an active role in SPMS, while this virus may contribute to the pathogenesis of RRMS triggering MS attacks in a subset of patients.