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Introduction To evaluate the impact of the COVID-19 pandemic on (1) number of clinical visits, (2) magnetic resonance (MR) scans, and (3) treatment prescriptions in a multiple sclerosis (MS) referral centre. Methods Retrospective study covering January 2018 to May 2021. Results The monthly mean (standard deviation [SD]) of visits performed in 2020 (814[137.6]) was similar to 2018 (741[99.7]; p = 0.153), and 2019 (797[116.3]; p = 0.747). During the COVID-19 period (2020 year), 36.3% of the activity was performed through telemedicine. The number of MR scans performed dropped by 76.6% during the “first wave” (March 14 to June 21, 2020) compared to the mean monthly activity in 2020 (183.5[68.9]), with a recovery during the subsequent two months. The monthly mean of treatment prescriptions approved in 2020 (24.1[7.0]) was lower than in 2019 (30[7.0]; p = 0.049), but similar to 2018 (23.8[8.0]; p = 0.727). Natalizumab prescriptions increased in the “first wave” and onwards, whereas anti-CD20 prescriptions decreased during the COVID-19 period. Conclusion Maintenance of the number of clinical visits was likely due to telemedicine adoption. Although the number of MR dramatically dropped during the “first wave”, an early recovery was observed. Treatment prescriptions suffered a slight quantitative decrease during 2020, whereas substantial qualitative changes were found in specific treatments.

Background and ObjectivesTo explore whether time to diagnosis, time to treatment initiation, and age to reach disability milestones have changed in patients with clinically isolated syndrome (CIS) according to different multiple sclerosis (MS) diagnostic criteria periods.MethodsThis retrospective study was based on data collected prospectively from the Barcelona-CIS cohort between 1994 and 2020. Patients were classified into 5 periods according to different MS criteria, and the times to MS diagnosis and treatment initiation were evaluated. The age at which patients with MS reached an Expanded Disability Status Scale (EDSS) score ≥3.0 was assessed by Cox regression analysis according to diagnostic criteria periods. Last, to remove the classic Will Rogers phenomenon by which the use of different MS criteria over time might result in a changes of prognosis, the 2017 McDonald criteria were applied, and age at EDSS score ≥3.0 was assessed by Cox regression.ResultsIn total, 1,174 patients were included. The median time from CIS to MS diagnosis and from CIS to treatment initiation showed a 77% and 82% reduction from the Poser to the McDonald 2017 diagnostic criteria periods, respectively. Patients of a given age diagnosed in more recent diagnostic criteria periods had a lower risk of reaching an EDSS score ≥3.0 than patients of the same age diagnosed in earlier diagnostic periods (reference category Poser period): adjusted hazard ratio (aHR) 0.47 (95% confidence interval 0.24–0.90) for McDonald 2001, aHR 0.25 (0.12–0.54) for McDonald 2005, aHR 0.30 (0.12–0.75) for McDonald 2010, and aHR 0.07 (0.01–0.45) for McDonald 2017. Patients in the early-treatment group displayed an aHR of 0.53 (0.33–0.85) of reaching age at EDSS score ≥3.0 compared to those in the late-treatment group. Changes in prognosis together with early-treatment effect were maintained after the exclusion of possible bias derived from the use of different diagnostic criteria over time (Will Rogers phenomenon).DiscussionA continuous decrease in the time to MS diagnosis and treatment initiation was observed across diagnostic criteria periods. Overall, patients diagnosed in more recent diagnostic criteria periods displayed a lower risk of reaching disability. The prognostic improvement is maintained after the Will Rogers phenomenon is discarded, and early treatment appears to be the most likely contributing factor.

Background: Inflammasomes are involved in the pathogenesis of different neuroimmune and neurodegenerative diseases, including multiple sclerosis (MS). In a previous study by our group, the nucleotide-binding oligomerization domain, leucine-rich repeat receptor and pyrin-domain containing 3 (NLRP3) inflammasome was reported to be associated with the response to interferon-beta in MS. Based on recent data showing the potential for the oral therapy fingolimod to inhibit NLRP3 inflammasome activation, here we investigated whether fingolimod could also be implicated in the response to this therapy in MS patients. Methods: NLRP3 gene expression levels were measured by real-time PCR in peripheral blood mononuclear cells at baseline and after 3, 6, and 12 months in a cohort of MS patients treated with fingolimod (N=23), dimethyl fumarate (N=21), and teriflunomide (N=21), and classified into responders and non-responders to the treatment according to clinical and radiological criteria. In a subgroup of fingolimod responders and non-responders, the percentage of ASC specks in monocytes was determined by flow cytometry, and the levels of IL-1β, IL-18, IL-6, TNFα, and galectin-3 were quantified by ELISA.Results: NLPR3 expression levels were significantly increased in fingolimod non-responders after 3 and 6 months of treatment but remained comparable in responders at all time points. These changes were not observed in non-responders to the other oral therapies tested. ASC speck formation in monocytes following LPS and ATP stimulation was significantly decreased in responders, but increased in non-responders after 6 months of fingolimod treatment. Pro-inflammatory cytokine release from stimulated PBMC was comparable between responders and non-responders, but galectin-3 levels on cell supernatants, as a marker of cell damage, were significantly increased in fingolimod non-responders. Conclusions: The differential effect of fingolimod on ASC speck formation in monocytes between responders and non-responders could be used as response biomarker after 6 months of fingolimod treatment, and suggests that fingolimod may exert their beneficial effects by reducing inflammasome signaling in a subset of MS patients.

BACKGROUND AND PURPOSE Both baseline prognostic factors and short-term predictors of treatment response can influence the long-term risk of disability accumulation in patients with relapsing-remitting multiple sclerosis (RRMS). The objective was to develop and validate a scoring system combining baseline prognostic factors and 1-year variables of treatment response into a single numeric score predicting the long-term risk of disability. METHODS We analysed two independent datasets of patients with RRMS who started interferon beta or glatiramer acetate, had an Expanded Disability Status Scale (EDSS) score

BACKGROUND AND PURPOSE To evaluate the effect of menopause on disability accumulation in women followed from their clinically isolated syndrome (CIS). METHODS We examined the longitudinal changes in Expanded Disability Status Scale (EDSS) scores from CIS until the last follow-up in women belonging to the Barcelona CIS prospective cohort, followed through their menopausal transition. The analysis is based on 13,718 EDSS measurements, with an average of 28 EDSS measurements per patient. Differences in EDSS trajectories between menopausal and nonmenopausal women, controlling for age and disease duration, were evaluated. We performed two sensitivity analyses in women with confirmed MS and in those experiencing early menopause. RESULTS From 764 eligible women, 496 (65%) responded to the questionnaire, and 74 (14.9%) reached menopause over the follow-up. We did not find a significant inflection point in EDSS trajectories around menopause (slope change -0.009; 95% CI -0.066; 0.046). The annual increase in EDSS over the complete course of the disease was significantly higher in menopausal women (0.049; 95% CI, 0.026-0.074) versus nonmenopausal (0.019; 95% CI, 0.008-0.031; interaction p value 0.025). This difference was lost when controlling for age and disease duration (EDSS annual increase of 0.059; 95% CI, 0.025-0.094 vs. 0.038; 95% CI, 0.021-0.057, respectively; interaction p value 0.321). No inflection point was detected when the analysis was restricted to women with confirmed MS or with earlier menopause. CONCLUSIONS Menopause is not associated with an increased risk of disability in a CIS population, considering EDSS trajectories throughout the course of the disease together with age and disease duration.

Background: The effect of disease-modifying therapies on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine response is unclear. Objectives: We aim to determine the immunological responses to SARS-CoV-2 in multiple sclerosis (MS) and anti-CD20-treated patients with other autoimmune diseases (AID). Methods: Humoral and cellular responses we determined before and 30-90 days after vaccination in patients with MS and anti-CD20-treated patients with other AID in two Catalan centers. Results: 457 patients were enrolled. Findings showed that humoral response decreased under anti-CD20s or sphingosine 1-phosphate receptor modulators (S1PRM) and with longer treatment duration and increased after 4.5 months from the last anti-CD20 infusion. Cellular response decreased in S1PRM-treated. Patients on anti-CD20 can present cellular responses even in the absence of antibodies. Conclusion: Anti-CD20s and S1PRM modify the immunological responses to SARS-CoV-2 vaccines.

BACKGROUND AND PURPOSE Both optical coherence tomography (OCT) and magnetic resonance imaging (MRI) volumetric measures have been postulated as potential biomarkers of multiple sclerosis (MS)-related disability. The aim of the study was to investigate the association between OCT and brain volume and spinal cord area (SCA) parameters in patients with relapsing MS and to assess their independent associations with disability. METHODS This was a cross-sectional analysis of 90 patients with MS who underwent OCT and MRI examination. Values of peripapillary retinal nerve fibre layer (pRNFL), ganglion cell/inner plexiform layer (GCIPL) and inner nuclear layer of eyes without previous optic neuritis were obtained. SCA and brain parenchymal fraction (BPF), grey and white matter fractions were obtained. Multivariable regression analyses were conducted with disability as dependent variable. RESULTS Lower pRNFL thickness and lower GCIPL volume as well as lower BPF, grey matter fraction and SCA were associated with a longer disease duration and a higher Expanded Disability Status Scale score. Lower pRNFL thickness and GCIPL volumes were associated with lower BPF and SCA. In the multivariable logistic regression analyses, pRNFL thickness and GCIPL volume outperformed MRI in predicting disability. CONCLUSIONS The OCT measures correlate with brain and spinal cord atrophy and appear more closely associated with disability than MRI volumetric measures.

Intrathecal production of kappa free light chains occurs in multiple sclerosis and can be measured using the kappa free light chain index. Kappa free light chain index values can be determined more easily than oligoclonal bands detection and seem more sensitive than the immunoglobulin (Ig)G index to diagnose multiple sclerosis. We assessed the value of oligoclonal bands, kappa free light chain index cut-offs 5.9, 6.6 and 10.61, and IgG index to diagnose multiple sclerosis with prospectively acquired data from a clinically isolated syndrome inception cohort. We selected patients with sufficient data to determine oligoclonal bands positivity, MRI dissemination in space and time, IgG index and sufficient quantities of paired CSF and blood samples to determine kappa free light chain indexes (n = 214). We used Kendall’s Tau coefficient to estimate concordance, calculated the number of additional diagnoses when adding each positive index to dissemination in space and positive oligoclonal bands, performed survival analyses for oligoclonal bands and each index with the outcomes second attack and 2017 MRI dissemination in space and time and estimated the diagnostic properties of oligoclonal bands and the different indexes for the previously mentioned outcomes at 5 years. Oligoclonal bands were positive in 138 patients (64.5%), kappa free light chain-5.9 in 136 (63.6%), kappa free light chain-6.6 in 135 (63.1%), kappa free light chain-10.61 in 126 (58.9%) and IgG index in 101 (47.2%). The highest concordance was between oligoclonal bands and kappa free light chain-6.6 (τ = 0.727) followed by oligoclonal bands and kappa free light chain-5.9 (τ = 0.716). Combining dissemination in space plus oligoclonal bands or kappa free light chain-5.9 increased the number of diagnosed patients by 11 (5.1%), with kappa free light chain-6.6 by 10 (4.7%), with kappa free light chain-10.61 by 9 (4.2%) and with IgG index by 3 (1.4%). Patients with positive oligoclonal bands or indexes reached second attack and MRI dissemination in space and time faster than patients with negative results (P < 0.0001 except IgG index in second attack: P = 0.016). In multivariable Cox models [adjusted hazard ratio (95% confidence interval)], the risk for second attack was very similar between kappa free light chain-5.9 [2.0 (0.9–4.3), P = 0.068] and kappa free light chain-6.6 [2.1 (1.1–4.2), P = 0.035]. The highest risk for MRI dissemination in space and time was demonstrated with kappa free light chain-5.9 [4.9 (2.5–9.6), P < 0.0001], followed by kappa free light chain-6.6 [3.4 (1.9–6.3), P < 0.0001]. Kappa free light chains-5.9 and -6.6 had a slightly higher diagnostic accuracy than oligoclonal bands for second attack (70.5, 71.1 and 67.8) and MRI dissemination in space and time (85.7, 85.1 and 81.0). Kappa free light chain indexes 5.9 and 6.6 performed slightly better than oligoclonal bands to assess multiple sclerosis risk and in terms of diagnostic accuracy. Given the concordance between oligoclonal bands and these indexes, we suggest using dissemination in space plus positive oligoclonal bands or positive kappa free light chain index as a modified criterion to diagnose multiple sclerosis.

ObjectiveThere is a lack of sensitive and specific biomarkers for use in progressive multiple sclerosis (MS). The study aimed to assess the potential of serum neurofilament light chain (sNfL) levels as biomarker of disability progression in patients with progressive MS.MethodsWe performed a prospective observational cohort study in 51 patients with progressive MS who participated in a 2-year phase II single-centre, randomised, double-blind, placebo-controlled trial of interferon-beta. Mean (SD) follow-up duration was 13.9 (6.2) years. Levels of sNfL were measured using a single molecule array immunoassay at baseline, 1, 2 and 6 years. Univariable and multivariable analyses were carried out to evaluate associations between sNfL levels and disability progression at short term (2 years), medium term (6 years) and long term (at the time of the last follow-up).ResultsA sNfL cut-off value of 10.2 pg/mL at baseline discriminated between long-term progressors and non-progressors with a 75% sensitivity and 67% specificity (adjusted OR 7.8; 95% CI 1.8 to 46.4; p=0.01). Similar performance to discriminate between long-term progressors and non-progressors was observed using age/body mass index-adjusted sNfL Z-scores derived from a normative database of healthy controls. A cut-off increase of 5.1 pg/mL in sNfL levels between baseline and 6 years also discriminated between long-term progressors and non-progressors with a 71% sensitivity and 86% specificity (adjusted OR 49.4; 95% CI 4.4 to 2×103; p=0.008).ConclusionssNfL can be considered a prognostic biomarker of future long-term disability progression in patients with progressive MS. These data expand the little knowledge existing on the role of sNfL as long-term prognostic biomarker in patients with progressive MS.

Background: The increase in available disease modifying therapies (DMTs) for multiple sclerosis has led to greater emphasis on improving treatment sequencing paradigms. This article summarises the opinions from a panel of 25 experts on treatment switching approaches in relapsing multiple sclerosis (RMS).Methods: A modified Delphi consensus process was carried out to develop clinically relevant statements for aiding treatment decisions in patients with RMS between the 16th January and the 9th October 2019. A sub-group of two experts (core group) carried out an extensive review of the literature and formulated 106 statements for the expert panel to evaluate.Results: From a total number of 106 statements that were submitted to the expert panel for critical evaluation, consensus (at least 80% of the panelists agreed) was reached on 99 of them. These statements cover treatment objectives, reasons for DMT switching, suboptimal response criteria, strategies for treatment change and washout periods.Conclusion: The agreed statements provide up-to-date guidance on DMT sequencing for optimal patient management.

Different treatment response scoring systems in treated MS patients exist. The objective was to assess the long-term predictive value of these systems in RRMS patients treated with self-injectable DMTs. RRMS-treated patients underwent brain MRI before the onset of therapy and 12 months thereafter, and neurological assessments every 6 months. Clinical and demographic characteristics were collected at baseline. After the first year of treatment, several scoring systems [Rio score (RS), modified Rio score (MRS), MAGNIMS score (MS), and ROAD score (RoS)] were calculated. Cox-Regression and survival analyses were performed to identify scores predicting long-term disability. We included 319 RRMS patients. Survival analyses showed that patients with RS > 1 and RoS > 3 had a significant risk of reaching an EDSS of 4.0 and 6.0 The score with the best sensitivity (61%) was the RoS, while the MRS showed the best specificity (88%). The RS showed the best positive predictive value (42%) and the best accuracy (81%). The combined measures integrated into different scores have an acceptable prognostic value for identifying patients with long-term disability. Thus, these data reinforce the concept of early treatment optimization to minimize the risk of long-term disability.

Background: Multiple sclerosis (MS) misdiagnosis may cause physical and emotional damage to patients. Objectives: The objective of this study is to determine the frequency and characteristics of MS misdiagnosis in patients referred to the Multiple Sclerosis Centre of Catalonia. Methods: We designed a prospective study including all new consecutive patients referred to our centre between July 2017 and June 2018. Instances of misdiagnosis were identified, and referral diagnosis and final diagnosis were compared after 1 year of follow-up. Association of misdiagnosis with magnetic resonance imaging (MRI) findings, presence of comorbidities and family history of autoimmunity were assessed. Results: A total of 354 patients were referred to our centre within the study period, 112 (31.8%) with ‘established MS’. Misdiagnosis was identified in eight out of 112 cases (7.1%). MRI identified multifocal white matter lesions, deemed non-specific or not suggestive of MS in all misdiagnosed cases. Patients with MS misdiagnosis had more comorbidities in general than patients with MS ( p = 0.026) as well as a personal history of autoimmunity ( p < 0.001). Conclusion: A low frequency of MS misdiagnosis was found in our clinical setting. Multifocal non-specific white matter lesions in referral MRI examinations and the presence of comorbidities, including a personal history of autoimmunity, seem to be contributing factors to misdiagnosis.

Background and purpose Information regarding multiple sclerosis (MS) patients with the 2019 novel coronavirus disease (COVID-19) is scarce. The study objective was to describe the incidence and characteristics of MS patients with COVID-19, to identify susceptibility and severity risk factors and to assess the proportion of positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serologies according to disease-modifying treatments. Methods This was a retrospective study of an MS cohort analysing data collected between February and May 2020. Cases were identified through an email survey and clinical visits. The relationship of demographic and MS characteristics with COVID-19 and of the disease-modifying treatments with SARS-CoV-2 serostatus were examined. Results Data from 48 suspected cases out of 758 valid respondents and from 45 COVID-19 cases identified through clinical visits were collected. Incidence was 6.3%. Nineteen (20.3%) patients were hospitalized and two (2.2%) died. Multivariable models determined that age (odds ratio [OR] per 10 years 0.53, 95% confidence interval [CI] 0.34-0.85), contact with a confirmed case (OR 197.02, 95% CI 56.36-688.79), residence in Barcelona (OR 2.23, 95% CI 1.03-4.80), MS duration (OR per 5 years 1.41, 95% CI 1.09-1.83) and time on anti-CD20 treatment (OR per 2 years 3.48, 95% CI 1.44-8.45) were independent factors for presenting COVID-19 and age (OR per 10 years 2.71, 95% CI 1.13-6.53) for a severe COVID-19. Out of the 79 (84.9%) with serological test, 45.6% generated antibodies, but only 17.6% of those on anti-CD20 therapies. Lymphopaenia or immunoglobulin levels did not relate to COVID-19. Conclusions Multiple sclerosis patients present similar incidence, risk factors and outcomes for COVID-19 as the general population. Patients treated with an anti-CD20 therapy for a longer period of time might be at a higher risk of COVID-19 and less than 20% generate an antibody response. Only age was related to severity.

[Background] Multiple sclerosis (MS) is a disease in which biomarker identification is fundamental to predict response to treatments and to deliver the optimal drug to patients. We previously found an association between rs7298096, a polymorphism upstream to the NINJ2 gene, and the 4-year response to interferon-β (IFNβ) treatment in MS patients., [Objectives] To analyse the association between rs7298096 and time to first relapse (TTFR) during IFNβ therapy in MS patients and to better investigate its functional role. [Methods] Survival analysis was applied in three MS cohorts from different countries (n = 1004). We also studied the role of the polymorphism on gene expression using GTEx portal and a luciferase assay. We interrogated GEO datasets to explore the relationship between NINJ2 expression, IFNβ and TTFR. [Results] Rs7298096AA patients show a shorter TTFR than rs7298096G-carriers (Pmeta-analysis = 3 × 10−4, hazard ratio = 1.41). Moreover, rs7298096AA is associated with a higher NINJ2 expression in blood (p = 7.0 × 10−6), which was confirmed in vitro (p = 0.009). Finally, NINJ2 expression is downregulated by IFNβ treatment and related to TTFR. [Conclusions] Rs7298096 could influence MS disease activity during IFNβ treatment by modulating NINJ2 expression in blood. The gene encodes for an adhesion molecule involved in inflammation and endothelial cells activation, supporting its role in MS.

Early evaluation of treatment response and prediction of disease evolution are key issues in the management of people with multiple sclerosis (MS). In the past 20 years, MRI has become the most useful paraclinical tool in both situations and is used clinically to assess the inflammatory component of the disease, particularly the presence and evolution of focal lesions — the pathological hallmark of MS. However, diffuse neurodegenerative processes that are at least partly independent of inflammatory mechanisms can develop early in people with MS and are closely related to disability. The effects of these neurodegenerative processes at a macroscopic level can be quantified by estimation of brain and spinal cord atrophy with MRI. MRI measurements of atrophy in MS have also been proposed as a complementary approach to lesion assessment to facilitate the prediction of clinical outcomes and to assess treatment responses. In this Consensus statement, the Magnetic Resonance Imaging in MS (MAGNIMS) study group critically review the application of brain and spinal cord atrophy in clinical practice in the management of MS, considering the role of atrophy measures in prognosis and treatment monitoring and the barriers to clinical use of these measures. On the basis of this review, the group makes consensus statements and recommendations for future research., In this Consensus statement, the Magnetic Resonance Imaging in MS (MAGNIMS) study group reviews the application of brain and spinal cord atrophy in clinical practice in the management of MS and makes consensus statements and recommendations for future research.

ObjectiveTo assess the added value of the optic nerve region (by using visual evoked potentials [VEPs]) to the current diagnostic criteria.MethodsFrom the Barcelona clinically isolated syndrome (CIS) cohort, patients with complete information to assess dissemination in space (DIS), the optic nerve region, and dissemination in time at baseline (n = 388) were selected. Modified DIS (modDIS) criteria were constructed by adding the optic nerve to the current DIS regions. The DIS and modDIS criteria were evaluated with univariable Cox proportional hazard regression analyses with the time to the second attack as the outcome. A subset of these patients who had at least 10 years of follow-up or a second attack occurring within 10 years (n = 151) were selected to assess the diagnostic performance. The analyses were also performed according to CIS topography (optic neuritis vs non–optic neuritis).ResultsThe addition of the optic nerve as a fifth region improved the diagnostic performance by slightly increasing the accuracy (2017 DIS 75.5%, modDIS 78.1%) and the sensitivity (2017 DIS 79.2%, modDIS 82.3%) without lowering the specificity (2017 DIS 52.4%, modDIS 52.4%). When the analysis was conducted according to CIS topography, the modDIS criteria performed similarly in both optic neuritis and non–optic neuritis CIS.ConclusionThe addition of the optic nerve, assessed by VEP, as a fifth region in the current DIS criteria slightly improves the diagnostic performance because it increases sensitivity without losing specificity.

The presence of oligoclonal bands in clinically isolated syndromes is an independent risk factor for developing multiple sclerosis and has been largely excluded from the more recent multiple sclerosis diagnostic criteria. Therefore, our objective was to explore the value of oligoclonal bands in the context of the 2010 McDonald criteria, especially in patients fulfilling exclusively dissemination in space at baseline. For this purpose, we selected 566 patients from a clinically isolated syndrome inception cohort who had IgG oligoclonal bands determination and sufficient data on baseline brain MRI to assess dissemination in space and time. We excluded the cases already fulfilling both dissemination in space and time and divided the remaining 398 into 'no dissemination in space and time' (n = 218), 'dissemination in space' (n = 164) and 'dissemination in time' (n = 16). We assessed Cox proportional hazards regression models with 2010 McDonald as the outcome, using 'no dissemination in space and time' with 0 lesions and negative oligoclonal bands as the reference for different subgroups according to oligoclonal bands status (positive/negative). To assess the diagnostic properties, we selected cases with a follow-up ≥3 years or fulfilling 2010 McDonald within 3 years of the clinically isolated syndrome (n = 314), and compared the performance of all 'dissemination in space' cases (n = 137) versus patients with 'dissemination in space' and positive oligoclonal bands (n = 101). The remaining patients classified as fulfilling 'dissemination in time' or 'no dissemination in space and time' were taken into account to calculate the diagnostic properties. The respective adjusted hazard ratios (95% confidence interval) were 1.5 (0.4-5.7) for 'no dissemination in space and time' with 0 lesions and positive oligoclonal bands, 3.1 (1.4-7.2) for 'no dissemination in space and time' with ≥1 lesions and negative oligoclonal bands, 7.4 (3.5-15.7) for 'no dissemination in space and time' with ≥1 lesions and positive oligoclonal bands, 10.4 (4.8-22.6) for 'dissemination in space' with negative oligoclonal bands, 15.3 (7.5-31.3) for 'dissemination in space' with positive oligoclonal bands, and 9.1 (3.5-23.4) for 'dissemination in time' (not subdivided due to the sample size). The specificity for all cases with 'dissemination in space' was 80.6 and increased to 88.1 after selecting those with positive oligoclonal bands. According to these results, we propose radiological dissemination in space at any time plus positive oligoclonal bands as an additional criterion for diagnosing multiple sclerosis.

We aimed to investigate whether NLR family, pyrin domain containing 3 (NLRP3) polymorphisms are associated with the response to interferon-beta (IFNβ) in multiple sclerosis (MS) patients. A total of 14 NLRP3 polymorphisms were genotyped in a cohort of 665 relapsing-remitting MS patients recruited across 5 centers and classified into responders and non-responders according to clinical-radiological criteria after 1 year of IFNβ treatment. A meta-analysis failed to demonstrate significant associations between the response to IFNβ and NLRP3 polymorphisms. These findings do not support a role of polymorphisms located in the NLRP3 gene and the response to IFNβ in MS patients.

Response to interferon-beta (IFN-beta) treatment is heterogeneous in multiple sclerosis (MS). We aimed to search for biomarkers predicting no evidence of disease activity (NEDA) status upon IFN-beta treatment in MS. 119 patients with relapsing-remitting MS (RRMS) initiating IFN-beta treatment were included in the study, and followed prospectively for 2 years. Neutralizing antibodies (NAb) were explored in serum samples obtained after 6 and 12 months of IFN-beta treatment. Soluble cytokines and blood lymphocytes were studied in basal samples by ELISA and flow cytometry, respectively. 9% of patients developed NAb. These antibodies were more frequent in patients receiving IFN-beta 1b than in those treated subcutaneous (p = 0.008) or intramuscular (p

Background: The usefulness of performing a spinal cord (SC) magnetic resonance imaging (MRI) in all clinically isolated syndromes (CIS) is controversial. Objective: To assess the value of SC lesions for predicting multiple sclerosis (MS) diagnosis and disability accrual in CIS. Methods: Concerning SC lesions and MS diagnosis (2010 McDonald), adjusted Cox regression analyses were performed in increasingly specific CIS groups: all cases ( n = 207), non-SC CIS ( n = 143), non-SC CIS with abnormal brain MRI ( n = 90) and non-SC CIS with abnormal brain MRI not fulfilling 2010 MS ( n = 67). For the outcome Expanded Disability Status Scale (EDSS) ≥3.0, similar analyses were performed in all cases ( n = 207), non-SC CIS ( n = 143) and SC CIS ( n = 64). Performance at 2 years was assessed for all outcomes. Results: The presence of SC lesions increased MS risk 2.0–2.6 times independently of factors like brain lesions. If considering lesion number, the risk ranged from 1.6 to 2.1 for one lesion to 2.4–3.3 for ≥2. SC lesions increased the short-term disability risk around fivefold, better demonstrated in non-SC CIS. SC lesions were very specific for evolution to MS and showed very high sensitivity for EDSS ≥3.0. Conclusion: SC lesions are independent predictors of MS in all CIS and contribute to short-term disability accrual. SC MRIs in CIS could be useful to estimate their prognosis.

Objective: To investigate the association between activity during interferon-beta (IFNβ) therapy and disability outcomes in patients with relapsing–remitting multiple sclerosis (RRMS). Methods: A longitudinal study based on two previously described cohorts of IFNβ-treated RRMS patients was conducted. Patients were classified according to clinical activity after 2 years (clinical cohort) or to clinical and radiological activity after 1 year (magnetic resonance imaging (MRI) cohort). Multivariate Cox models were calculated for early disease activity predicting long-term disability. Results: A total of 516 patients from two different cohorts were included in the analyses. Persistent clinical disease activity during the first 2 years of therapy predicted severe long-term disability (clinical cohort). In the MRI cohort, modified Rio score and no or minimal evidence of disease activity (NEDA/MEDA) did not identify patients with risk of Expanded Disability Status Scale (EDSS) worsening. However, a Rio score ≥ 2 (hazard ratio (HR): 3.3, 95% confidence interval (CI): 1.7–6.4); ≥3 new T2 lesions (HR: 2.9, 95% CI: 1.5–5.6); or ≥2 Gd-enhancing lesions (HR: 2.1, 95% CI: 1.1–4) were able to identify patients with EDSS worsening. Conclusion: Although early activity during IFNβ therapy is associated with poor long-term outcomes, minimal degree of activity does not seem to be predictive of EDSS worsening over 6.7-year mean follow-up.

Alemtuzumab, a humanized monoclonal antibody for the treatment of relapsing-remitting multiple sclerosis, produce the rapid depletion of all mature lymphocytes. For this reason, patients are at an increased risk of developing infections due to the reactivation of latent agents or acquired microorganisms. Most infections reported during the phase III trials were mild or moderate in severity, while serious infections were surprisingly uncommon.1 However, during the postmarketing use of alemtuzumab, several opportunistic infections have been reported.2–5 We describe a patient who presented simultaneous cytomegalovirus (CMV) reactivation and Listeria meningitis promptly following the first course of alemtuzumab.

Objective: To study the contribution of the symptomatic lesion in establishing multiple sclerosis (MS) diagnosis and prognosis. Methods: We performed an observational study based on a prospective clinically isolated syndrome (CIS) cohort of 1,107 patients recruited for clinical and brain MRI follow-up from 1995 to 2014. Eligible patients (n = 954) were divided into 4 groups according to baseline MRI: patients with a normal MRI (n = 290); patients with a single asymptomatic lesion (n = 18); patients with a single cord/brainstem symptomatic lesion (n = 35); and patients with more than 1 lesion (n = 611). For each group, we studied the risk of second attack, with 2005 McDonald MS and Expanded Disability Status Scale 3.0, using univariable and multivariable regression models adjusted by age, sex, oligoclonal bands, and disease-modifying treatments. We tested the diagnostic performance of a modified dissemination in space (DIS) criterion that includes symptomatic lesions in the total count and compared it to the DIS criteria (at least 1 asymptomatic lesion in at least 2 of the 4 MS characteristic MS locations) for all patients and for the subgroup of patients with brainstem or spinal cord topography. Results: Patients with a cord/brainstem single symptomatic lesion have a higher risk of second attack and disability accumulation than patients with 0 lesions but have a similar risk compared to patients with 1 asymptomatic lesion. Diagnostic properties are reasonably maintained when the symptomatic lesion qualifies for DIS. Conclusions: Despite the recommendations of the 2010 McDonald criteria, symptomatic lesions should be taken into account when considering the diagnosis and prognosis of patients with CIS.

Background: Brain volume loss (BVL) is a key outcome in multiple sclerosis (MS) trials. Natalizumab is highly effective on inflammation with moderate impact on atrophy. Objective: To explore BVL in patients receiving natalizumab with an emphasis on grey matter (GM). Methods: We performed a retrospective post hoc analysis of BVL in 38 patients receiving natalizumab for 3 years using longitudinal voxel-based morphometry (VBM) and FreeSurfer. Results: Significant BVL was observed during first year: brain parenchymal fraction (BPF): −1.12% ( p right fronto-parietal cortex, right > left hippocampus and left caudate. FreeSurfer showed significant volume losses in subcortical GM, brainstem and cerebellum, and cortical thinning in the left insula. In the second year, only WMF decrease (−0.6%; p = 0.015) was observed with no VBM changes, although FreeSurfer detected significant volume loss in thalamus, hippocampus and cerebellum. Baseline gadolinium enhancement influenced WMF and BPF changes during the first year, but not GMF. Patients with confirmed Expanded Disability Status Scale (EDSS) worsening at 3 years had lower baseline GMF and left thalamus volume and greater BVL over follow-up. Conclusion: BVL develops mainly during the first year of natalizumab therapy. GM changes are independent of baseline inflammation and correlate with disability.

Objectives: To explore long-term effects of treatment and prognostic relevance of variables assessed at baseline and during the European secondary progressive multiple sclerosis (SPMS) trial of interferon beta 1b (IFNB-1b). Methods: We assessed 362 patients (60% female; median age 41 years; Expanded Disability Status Scale (EDSS): 5.5; 51% randomized to IFNB-1b) for their EDSS and treatment history after 10 years. Non-parametric analysis of covariance (ANCOVA) and multivariate linear regression models were applied. Results: Median EDSS was 6.0 at the end of the randomized controlled trial (RCT), in the IFNB-1b and placebo groups, and 7.0 in long-term follow-up patients (those receiving IFNB-1b in the RCT were 6.5 and those receiving placebo in the RCT were 7.0; p = 0.086). 24 patients (6.6%) were deceased. The EDSS at baseline and the EDSS change during the RCT were the most important predictors of the EDSS 10 years later (partial R2: 0.47). The ability to predict changes in EDSS 10 years after the RCT was limited ( R2: 0.12). Magnetic resonance imaging (MRI) measures remained in the predictive models, but explained < 5% of the variability. Conclusions: The results from this analysis did not provide convincing evidence to support a favorable long-term outcome in those patients allocated IFNB-1b during the RCT, in our SPMS cohort. The progressive stage of the disease remains largely unpredictable by clinical and conventional MRI measures, so better prognostic markers are needed.

OBJECTIVE A pseudoatrophy effect, mostly affecting white matter, can be observed in patients with multiple sclerosis (MS) early on natalizumab therapy. We aimed to investigate whether a similar pattern could be found after interferon-beta treatment onset. METHODS From a prospective, ongoing cohort, 123 patients treated with interferon-beta were included. A brain MRI was performed at baseline (3 months prior) and 12 months after therapy onset in all patients. SPM8 software was used for volumetric analysis. Brain parenchymal, gray and white matter volumes at baseline and follow-up were obtained, allowing calculation of percentage of volume changes (BVc, GMVc, and WMVc, respectively). Descriptive statistics and linear regression models were performed. RESULTS Eighty-four patients were analyzed (39 patients were excluded mostly due to incomplete MRI protocol or segmentation errors); baseline mean age was 33.6 years (SD 8.7), median disease duration was 2.8 years (.3-14), and median EDSS was 1.5 (0-6). Forty-nine patients (58.3%) had baseline gadolinium-enhancing (Gd+) lesions with a median number of 1 (0-18). The regression analysis (adjusted by the number of Gd+ at follow-up MRI, age, disease duration, and baseline EDSS) showed that a higher baseline number of Gd+ lesions was predictive of larger decreases in BVc and WMVc (P = .013 and P = .003, respectively) but not GMVc (P = .777). CONCLUSION Concurrent inflammation has an impact on brain volume measurements (especially white matter) during the first year of interferon-beta therapy, and should be taken into account when interpreting early brain volume changes on therapy.

Natural history studies have identified factors that predict evolution to multiple sclerosis or risk of disability accumulation over time. Although these studies are based on large multicentre cohorts with long follow-ups, they have limitations such as lack of standardized protocols, a retrospective data collection or lack of a systematic magnetic resonance imaging acquisition and analysis protocol, often resulting in failure to take magnetic resonance and oligoclonal bands into account as joint covariates in the prediction models. To overcome some of these limitations, the aim of our study was to identify and stratify baseline demographic, clinical, radiological and biological characteristics that might predict multiple sclerosis development and disability accumulation using a multivariate approach based on a large prospective cohort of patients with clinically isolated syndromes. From 1995 to 2013, 1058 patients with clinically isolated syndromes were included. We evaluated the influence of baseline prognostic factors on the risk for developing clinically definite multiple sclerosis, McDonald multiple sclerosis, and disability accumulation (Expanded Disability Status Scale score of 3.0) based on univariate (hazard ratio with 95% confidence intervals) and multivariate (adjusted hazard ratio with 95% confidence intervals) Cox regression models. We ultimately included 1015 patients followed for a mean of 81 (standard deviation = 57) months. Female/male ratio was 2.1. Females exhibited a similar risk of conversion to multiple sclerosis and of disability accumulation compared to males. Each younger decade at onset was associated with a greater risk of conversion to multiple sclerosis and with a protective effect on disability. Patients with optic neuritis had a lower risk of clinically definite multiple sclerosis [hazard ratio 0.6 (0.5-0.8)] and disability progression [hazard ratio 0.5 (0.3-0.8)]; however, this protective effect remained marginal only for disability [adjusted hazard ratio 0.6 (0.4-1.0)] in adjusted models. The presence of oligoclonal bands increased the risk of clinically definite multiple sclerosis [adjusted hazard ratio 1.3 (1.0-1.8)] and of disability [adjusted hazard ratio 2.0 (1.2-3.6)] independently of other factors. The presence of 10 or more brain lesions on magnetic resonance increased the risk of clinically definite multiple sclerosis [adjusted hazard ratio 11.3 (6.7-19.3)] and disability [adjusted hazard ratio 2.9 (1.4-6.0)]. Disease-modifying treatment before the second attack reduced the risk of McDonald multiple sclerosis [adjusted hazard ratio 0.6 (0.4-0.9)] and disability accumulation [adjusted hazard ratio 0.5 (0.3-0.9)]. We conclude that the demographic and topographic characteristics are low-impact prognostic factors, the presence of oligoclonal bands is a medium-impact prognostic factor, and the number of lesions on brain magnetic resonance is a high-impact prognostic factor.

Multiple sclerosis is a multifocal demyelinating disease leading to progressive neurodegeneration caused by an autoimmune response in genetically predisposed individuals. In the last few years, the knowledge and management of this disease has been revolutionized by a series of findings. The present article reviews pathological features of the disease, in which cortical involvement is increasingly implicated, and aspects related to novel pathogenic mechanisms, such as the role of the microbiota in the genesis of multiple sclerosis, as well as recent contributions from the fields of epidemiology and genetics. Also reviewed are the latest diagnostic criteria, which currently allow a much earlier diagnosis, with clear therapeutic implications.

The prognostic role of cerebrospinal fluid molecular biomarkers determined in early pathogenic stages of multiple sclerosis has yet to be defined. In the present study, we aimed to investigate the prognostic value of chitinase 3 like 1 (CHI3L1), neurofilament light chain, and oligoclonal bands for conversion to clinically isolated syndrome and to multiple sclerosis in 75 patients with radiologically isolated syndrome. Cerebrospinal fluid levels of CHI3L1 and neurofilament light chain were measured by enzyme-linked immunosorbent assay. Uni- and multivariable Cox regression models including as covariates age at diagnosis of radiologically isolated syndrome, number of brain lesions, sex and treatment were used to investigate associations between cerebrospinal fluid CHI3L1 and neurofilament light chain levels and time to conversion to clinically isolated syndrome and multiple sclerosis. Neurofilament light chain levels and oligoclonal bands were independent risk factors for the development of clinically isolated syndrome (hazard ratio = 1.02, P = 0.019, and hazard ratio = 14.7, P = 0.012, respectively) and multiple sclerosis (hazard ratio = 1.03, P = 0.003, and hazard ratio = 8.9, P = 0.046, respectively). The best cut-off to classify cerebrospinal fluid neurofilament light chain levels into high and low was 619 ng/l, and high neurofilament light chain levels were associated with a trend to shorter time to clinically isolated syndrome (P = 0.079) and significant shorter time to multiple sclerosis (P = 0.017). Similarly, patients with radiologically isolated syndrome presenting positive oligoclonal bands converted faster to clinically isolated syndrome and multiple sclerosis (P = 0.005 and P = 0.008, respectively). The effects of high neurofilament light chain levels shortening time to clinically isolated syndrome and multiple sclerosis were more pronounced in radiologically isolated syndrome patients with ≥37 years compared to younger patients. Cerebrospinal fluid CHI3L1 levels did not influence conversion to clinically isolated syndrome and multiple sclerosis in radiologically isolated syndrome patients. Overall, these findings suggest that cerebrospinal neurofilament light chain levels and oligoclonal bands are independent predictors of clinical conversion in patients with radiologically isolated syndrome. The association with a faster development of multiple sclerosis reinforces the importance of cerebrospinal fluid analysis in patients with radiologically isolated syndrome.

Background: Natalizumab is associated with the occasional occurrence of progressive multifocal leukoencephalopathy (PML). While natalizumab-associated PML is well described in multiple sclerosis (MS) patients, herpes and other infections have rarely been reported. Objective: To report a case of varicella-zoster (VZV) meningovasculitis in a MS patient treated with natalizumab. Methods: Case report. Results: A 48-year-old woman diagnosed with MS in treatment with natalizumab (Expanded Disability Status Scale (EDSS): 4.0). After 72 infusions, she complained of a holocraneal headache and a new unsteady gait with diplopia (EDSS: 5.0). A brain and spinal cord magnetic resonance (MR) scan showed a multifocal leptomeningeal enhancing nodular lesions and an angiography revealed irregularity of the proximal segments of cerebral arteries. Testing for VZV DNA by polymerase chain reaction (PCR) amplification was positive in cerebrospinal fluid. Treatment with endovenous acyclovir was started. After clinical improvement (EDSS: 4.5), treatment with natalizumab was restarted associated with oral acyclovir as prophylaxis. Conclusion: Neurologists should be aware of other possible neuroinfections besides PML in MS patients under natalizumab.

Objectives:To assess the contributions of cortico-juxtacortical and corpus callosum lesions to multiple sclerosis diagnosis and to compare the value of ≥1 vs ≥3 periventricular lesions in clinically isolated syndromes (CIS).Methods:Step 1: We evaluated lesion topography classifications in 657 patients with CIS with stepwise Cox proportional hazards regression models considering second attack as the outcome. Step 2: We established 2 dissemination in space (DIS) versions according to the periventricular lesion cutoffs of ≥1 and ≥3 and assessed their performance at 10 years with second attack as the outcome, first individually and then combined with dissemination in time (DIT) in all cases (n = 326), by age, and by CIS topography.Results:Step 1: The models (hazard ratios [95% confidence interval]) favored ≥1 over ≥3 periventricular lesions (2.5 [1.7–3.6]) and cortico-juxtacortical over juxtacortical lesions (1.4 [1.0–1.8]). Callosal lesions were not selected. Step 2: DIS specificity with ≥1 periventricular lesions was slightly lower than with ≥3 (59.1 vs 61.4) and the same after adding DIT (88.6). Regarding age, ≥3 periventricular lesions improved DIS specificity over ≥1 lesions in the 40–49 years of age bracket (66.7 vs 58.3). This difference disappeared when adding DIT (83.3). Optic neuritis had a similar pattern when evaluating CIS topographies.Conclusions:Our results comply with the Magnetic Resonance Imaging in Multiple Sclerosis (MAGNIMS) consensus recommendation of combining cortical and juxtacortical lesions into a single term when possible. Concerning periventricular lesions, maintaining the current ≥1 cutoff in the McDonald criteria does not compromise specificity in typical CIS cases, but attention should be paid to older patients or optic neuritis cases.

MR imaging is the most sensitive tool for identifying lesions in patients with multiple sclerosis (MS). MR imaging has also acquired an essential role in the detection of complications arising from these treatments and in the assessment and prediction of efficacy. In the future, other radiological measures that have shown prognostic value may be incorporated within the models for predicting treatment response. This article examines the role of MR imaging as a prognostic tool in patients with MS and the recommendations that have been proposed in recent years to monitor patients who are treated with disease-modifying drugs.

Background: Investigation of atrophy data from a pivotal natalizumab trial has demonstrated an increased rate of volume loss, compared to placebo, after the first year of therapy. It was considered to be probably due to a pseudoatrophy effect. Objective: To assess grey and white matter volume changes and their relation to global brain volume changes and to baseline inflammation, for patients under natalizumab therapy. Methods: We selected 45 patients on natalizumab therapy for at least 24 months, with magnetic resonance imaging (MRI) scans at baseline, 12 and 24 months. We calculated the percentage brain volume change (PBVC) for the first and second year, using SIENA software. Grey and white matter fractions (GMF and WMF, respectively) for the first year were calculated with SPM5, using lesion masks. After quality checks, six patients were excluded. We studied the predictive variables of change in brain volumes. Results: The PBVC decrease was faster during the first year (−1.10% ± 1.43%), as compared to the second (−0.51% ± 0.96%) ( p = 0.037). These differences were more marked in patients with baseline gadolinium-enhancing lesions ( p = 0.005). Mean GMF and WMF changes during the first year of treatment were +1.15% (n.s.) and −1.72% ( p = 0.017), respectively. The presence of active lesions at baseline MRI predicted PBVC ( p = 0.022) and WMF change ( p = 0.026) during the first year of treatment, after adjusting for age and corticosteroid treatment. No predictors were found for GMF volume changes. Conclusion: Early brain volume loss during natalizumab therapy is mainly due to WMF volume loss and it is related to the inflammatory activity present at the onset of therapy. We found that the pseudoatrophy effect is mostly due to white matter volume changes.

Chitinase 3-like 1 (CHI3L1) plays a prognostic role in patients with multiple sclerosis (MS). Here, we investigated a potential association between CHI3L1 and the response to interferon-beta (IFNβ) and glatiramer acetate (GA). Serum CHI3L1 levels were measured by ELISA in 117 relapsing-remitting MS (RRMS) patients, 76 IFNβ-treated and 41 GA-treated patients. CHI3L1 levels were increased by GA (p = 0.014) but unchanged by IFNβ (p = 0.830). CHI3L1 was associated with IFNβ response and levels were higher in non-responder group (p = 0.020), while GA showed no responder effect (p = 0.943). These results suggest a role for CHI3L1 as response biomarker to IFNβ in RRMS patients., The authors thank the “Red Española de Esclerosis Múltiple (REEM)” sponsored by the “Fondo de Investigación Sanitaria” (FIS), Ministry of Science and Innovation, Spain, and the “Ajuts per donar Suport als Grups de Recerca de Catalunya”, sponsored by the “Agència de Gestió d'Ajuts Universitaris i de Recerca” (AGAUR), Generalitat de Catalunya, Spain.

Little is known about the mechanisms leading to neurodegeneration in multiple sclerosis (MS) and the role of peripheral blood cells in this neurodegenerative component. We aimed to correlate brain radiological phenotypes defined by high and low neurodegeneration with gene expression profiling of peripheral blood mononuclear cells (PBMC) from MS patients. Magnetic resonance imaging (MRI) scans from 64 patients with relapsing-remitting MS (RRMS) were classified into radiological phenotypes characterized by low (N = 27) and high (N = 37) neurodegeneration according to the number of contrast-enhancing lesions, the relative volume of non-enhancing black holes on T1-weighted images, and the brain parenchymal fraction. Gene expression profiling was determined in PBMC using microarrays, and validation of selected genes was performed by polymerase chain reaction (PCR). B-cell immunophenotyping was conducted by flow cytometry. Microarray analysis revealed the B-cell specific genes FCRL1, FCRL2, FCRL5 (Fc receptor-like 1, 2 and 5 respectively), and CD22 as the top differentially expressed genes between patients with high and low neurodegeneration. Levels for these genes were significantly down-regulated in PBMC from patients with MRI phenotypes characterized by high neurodegeneration and microarray findings were validated by PCR. In patients with high neurodegeneration, immunophenotyping showed a significant increase in the expression of the B-cell activation markers CD80 in naïve B cells (CD45+/CD19+/CD27-/IgD+), unswitched memory B cells (CD45+/CD19+/CD27+/IgD+), and switched memory B cells (CD45+/CD19+/CD27+/IgD-), and CD86 in naïve and switched memory B cells. These results suggest that RRMS patients with radiological phenotypes showing high neurodegeneration have changes in B cells characterized by down-regulation of B-cell-specific genes and increased activation status.

Objective: The aim of this study is to report the clinical profile and outcome of longitudinally extensive transverse myelitis (LETM). Methods: We prospectively studied adult patients who presented with LETM from January 2008 to December 2011. Information on demographic, clinical course, magnetic resonance imaging (MRI) and outcome was collected. HLA-DRB1 genotype was compared with those of 225 normal controls and patients with MS (228) and neuromyelitis optica (NMO) (22). Results: In total, 23 patients (16 female) with a median age of 44.5 years (range: 20–77 years) were included. Most (74%) had moderate–severe disability at nadir (48% non-ambulatory), normal/non-multiple sclerosis (MS) brain MRI (96%) and a median MRI cord lesion of 5 vertebral segments (range: 3–19). Laboratory analysis showed cerebrospinal fluid pleocytosis (45%), NMO-IgG (9%), antinuclear antibodies (70%), and genotype HLA-DRB1*13 (57%). The frequency of DRB1*13 genotype was higher compared with controls ( p=0.002), MS ( p=0.001) and NMO ( p= 0.003) patients. After a median follow-up of 32 months, one patient converted to MS, two had relapsing LETM with NMO-IgG, and 20 remained as idiopathic with recurrences in four (20%). Twelve (52%) patients recovered with minimal disability (Expanded Disability Status Scale (EDSS) Conclusions: Inflammatory LETM is mostly idiopathic with a good outcome. It includes a relatively homogenous group of patients with an overrepresentation of the HLA-DRB1*13 genotype. EDSS at nadir is a predictor of the final outcome and extension of the myelitis of the recurrence risk.

Multifocal progressive leukoencephalopathy (PML) is associated with JC virus (JCV) seropositivity, past immunosuppression, and natalizumab treatment for two years or more. The aim of our study was to investigate the rate of treatment discontinuation after stratifying for the three risk factors in a group of 104 natalizumab-treated patients with relapsing–remitting multiple sclerosis. We investigated JCV serological status in our population. We then divided patients into groups according to their PML risk. Treatment indication was reassessed. Of the patients, 64 (61.5%) were JCV seropositive. Amongst seropositive patients on natalizumab for 2 years or more, 10 had received immunosuppression (group A), and 38 had not (group B). After an informed and shared decision-making process, 6/10 (60%) from group A compared with 9/38 (23.7%) from group B discontinued treatment ( p=0.027). In groups A and B, discontinuation also depended upon doctors’ views ( p=0.019, group A; p=0.010, group B) and clinical outcomes ( p=0.021, group A). No-one from low–intermediate risk groups discontinued. The decision to discontinue natalizumab treatment is complex, even when clear PML risk rates are described. Clinical outcomes and doctors’ idiosyncrasies play a crucial part in patients’ final choice.

Objective: Interferon-beta (IFNβ) has demonstrated beneficial effects reducing disease activity in multiple sclerosis (MS) patients, but a relatively large proportion of patients do not respond to treatment. Here we aimed to investigate the roles of the Toll-like receptor 4 (TLR4) and the type I IFN pathways in the response to IFNβ in MS patients. Methods: The expression levels of several components of the TLR4 and the type I IFN pathways were determined by flow cytometry and real-time polymerase chain reaction (PCR) in peripheral blood mononuclear cells (PBMCs) from a cohort of 85 MS patients treated for at least 2 years with IFNβ and classified into responders, intermediate responders, and nonresponders based on their clinical response to treatment. Thirty-two healthy controls were also included in the study for comparison purposes. Results: Compared to responders and controls, PBMCs from nonresponders and intermediate responders were characterized by increased baseline expression levels of endogenous IFNβ and elevated IFN receptor 1 (IFNAR1) expression in monocytes. Furthermore, the capacity of IFNβ to induce its own expression was deficient in cells from nonresponders compared with responders. Baseline expression of the interleukin-1 receptor-associated kinase 3 (IRAK3), a negative regulator of TLR4 signaling primarily expressed in monocytes, was found to be significantly decreased in IFNβ responders compared with nonresponders. Interpretation: These findings provide evidence of the involvement of the TLR4 and type I IFN signaling pathways in the response to IFNβ. ANN NEUROL 2011;70:634–645