Sunlight exposure exerts immunomodulatory effects to reduce multiple sclerosis severity.

Multiple sclerosis (MS) disease risk is associated with reduced sun-exposure. This study assessed the relationship between measures of sun exposure (vitamin D [vitD], latitude) and MS severity in the setting of two multicenter cohort studies (nNationMS = 946, nBIONAT = 990). Additionally, effect-modification by medication and photosensitivity-associated MC1R variants was assessed. High serum vitD was associated with a reduced MS severity score (MSSS), reduced risk for relapses, and lower disability accumulation over time. Low latitude was associated with higher vitD, lower MSSS, fewer gadolinium-enhancing lesions, and lower disability accumulation. The association of latitude with disability was lacking in IFN-ß-treated patients. In carriers of MC1R:rs1805008(T), who reported increased sensitivity toward sunlight, lower latitude was associated with higher MRI activity, whereas for noncarriers there was less MRI activity at lower latitudes. In a further exploratory approach, the effect of ultraviolet (UV)-phototherapy on the transcriptome of immune cells of MS patients was assessed using samples from an earlier study. Phototherapy induced a vitD and type I IFN signature that was most apparent in monocytes but that could also be detected in B and T cells. In summary, our study suggests beneficial effects of sun exposure on established MS, as demonstrated by a correlative network between the three factors: Latitude, vitD, and disease severity. However, sun exposure might be detrimental for photosensitive patients. Furthermore, a direct induction of type I IFNs through sun exposure could be another mechanism of UV-mediated immune-modulation in MS.

Identification of Umbre Orthobunyavirus as a Novel Zoonotic Virus Responsible for Lethal Encephalitis in 2 French Patients with Hypogammaglobulinemia.

BACKGROUND: Human encephalitis represents a medical challenge from a diagnostic and therapeutic point of view. We investigated the cause of 2 fatal cases of encephalitis of unknown origin in immunocompromised patients. METHODS: Untargeted metatranscriptomics was applied on the brain tissue of 2 patients to search for pathogens (viruses, bacteria, fungi, or protozoans) without a prior hypothesis. RESULTS: Umbre arbovirus, an orthobunyavirus never previously identified in humans, was found in 2 patients. In situ hybridization and reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR) showed that Umbre virus infected neurons and replicated at high titers. The virus was not detected in cerebrospinal fluid by RT-qPCR. Viral sequences related to Koongol virus, another orthobunyavirus close to Umbre virus, were found in Culex pipiens mosquitoes captured in the south of France where the patients had spent some time before the onset of symptoms, demonstrating the presence of the same clade of arboviruses in Europe and their potential public health impact. A serological survey conducted in the same area did not identify individuals positive for Umbre virus. The absence of seropositivity in the population may not reflect the actual risk of disease transmission in immunocompromised individuals. CONCLUSIONS: Umbre arbovirus can cause encephalitis in immunocompromised humans and is present in Europe.

Dimethyl fumarate treatment shifts the immune environment toward an anti-inflammatory cell profile while maintaining protective humoral immunity.

BACKGROUND: Delayed-release dimethyl fumarate (DMF) demonstrates sustained efficacy and safety for relapsing forms of MS. Absolute lymphocyte count (ALC) is reduced initially, then stabilizes on treatment. OBJECTIVE: PROCLAIM, a 96-week, prospective, open-label, phase 3b study, assessed lymphocyte subsets and immunoglobulin (Ig) levels during 48 and 96 weeks (W) of DMF treatment. METHODS: Patients received 240 mg DMF BID. Endpoints: lymphocyte subset count changes (primary); Ig isotypes and ALC changes (secondary); adverse events and relationship between ALC changes and ARR/EDSS (exploratory); and neurofilament assessment (ad hoc). RESULTS: Of 218 patients enrolled, 158 (72%) completed the study. Median ALC decreased 39% from baseline to W96 (BL-W96), stabilizing above the lower limit of normal (baseline: 1.82 × 109/L; W48: 1.06 × 109/L; W96: 1.05 × 109/L). CD4 + and CD8 + T cells correlated highly with ALC from BL-W96 (p < 0.001). Relative to total T cells, naive CD4 + and CD8 + T cells increased, whereas CD4 + and CD8 + central and effector memory T cells decreased. Total IgA, IgG, IgM, and IgG1-4 subclass levels remained stable. Adverse event rates were similar across ALC subgroups. ARR, EDSS, and neurofilament were not correlated with ALCs. CONCLUSION: Lymphocyte decreases with DMF were maintained over treatment, yet immunoglobulins remained stable. No increase in infection incidence was observed in patients with or without lymphopenia. SUPPORT: Biogen.

BEST-MS: A prospective head-to-head comparative study of natalizumab and fingolimod in active relapsing MS.

BACKGROUND: There are few head-to-head studies to compare highly active treatments in multiple sclerosis (MS). OBJECTIVE: The aim of this study was to compare the effectiveness between natalizumab (NTZ) and fingolimod (FTY) in active relapsing-remitting MS. METHOD: Best Escalation STrategy in Multiple Sclerosis (BEST-MS) is a multicentric, prospective study with a 12-month follow-up including patients with active MS. Treatment choice was at the discretion of physician. Clinical and magnetic resonance imaging (MRI) data were collected at baseline and at 12 months. The primary outcome was the proportion of patients reaching no evidence of disease activity (NEDA) at 12 months. Secondary outcomes included annualized relapse rate and MRI activity. RESULTS: A total of 223 patients were included (NTZ: 109 and FTY: 114). Treatment groups were well balanced at baseline. Proportion of NEDA patients was 47.8% in NTZ group versus 30.4% in FTY group (p = 0.015). This superiority was driven by annualized relapse rate and MRI activity. In the multivariate analysis, treatment group was the only factor associated with NEDA at 12 months with a lower probability in FTY group (odds ratio (OR) = 0.49, p = 0.029). CONCLUSION: BEST-MS is a prospective study that compared head-to-head the effectiveness of NTZ and FTY in active relapsing-remitting MS. Our results suggest a superiority of NTZ over FTY.

Oral nomegestrol acetate and transdermal 17-beta-estradiol for preventing post-partum relapses in multiple sclerosis: The POPARTMUS study.

BACKGROUND: Sex steroids could explain the course of multiple sclerosis (MS) in pregnancy. OBJECTIVE: To compare the annualized relapse rate (ARR) 12 weeks post-partum in women treated with nomegestrol acetate (NOMAc) and 17-beta-estradiol (E2) versus placebo. METHODS: POPARTMUS is a randomized, proof-of-concept trial in women with MS, receiving oral NOMAc 10 mg/day and transdermal estradiol 75 µg/week, or placebo. RESULTS: Recruitment was stopped prematurely due to slow inclusions (n = 202). No treatment effect was observed on ARR after 12 weeks (sex steroids = 0.90 (0.58-1.39), placebo = 0.97 (0.63-1.50) (p = 0.79)). CONCLUSION: POPARTMUS failed showing efficacy of a NOMAc-E2 combination in preventing post-partum relapses.

Frequency and characteristics of short versus longitudinally extensive myelitis in adults with MOG antibodies: A retrospective multicentric study.

OBJECTIVES: We aim to (1) determine the frequency and distinctive features of short myelitis (SM) and longitudinally extensive transverse myelitis (LETM) in a cohort of adults with myelin oligodendrocyte glycoprotein (MOG)-antibody (Ab)-associated myelitis and (2) determine baseline prognostic factors among MOG-Ab-positive patients whose disease started with myelitis. MATERIAL AND METHODS: We retrospectively analyzed clinical and paraclinical variables from a multicentric French cohort of adults with MOG-Ab-associated myelitis. At last follow-up, patients were classified into two groups according to the severity of the Expanded Disability Status Scale (EDSS) as ⩽2.5 or ⩾3.0. RESULTS: Seventy-three patients with at least one episode of myelitis over disease course were included; among them, 28 (38.4%) presented with SM at the time of the first myelitis. Motor and sphincter involvement was less frequently observed in SM (51.9% and 48.2%, respectively) than in LETM patients (83.3% and 78.6%, respectively), p = 0.007 and p = 0.017; 61% of LETM patients displayed brain lesions compared to 28.6% in the SM group, p = 0.008, and the thoracic segment was more frequently involved in the LETM (82.2%) than in the SM group (39.3%), p < 0.001. EDSS at last follow-up was higher in LETM (median 3.0 (interquartile range: 2.0-4.0)) compared to SM patients (2.0, (1.0-3.0)), p = 0.042. Finally, a higher EDSS at onset was identified as the only independent risk factor for EDSS ⩾3.0 (odds ratio, 1.40, 95% confidence interval (CI): 1.01-1.95, p = 0.046). CONCLUSION: SM in MOG-Ab-associated disease is not rare. The severity at onset was the only independent factor related to the final prognosis in MOG-Ab-associated myelitis.

Focal and diffuse cervical spinal cord damage in patients with early relapsing-remitting MS: A multicentre magnetisation transfer ratio study.

BACKGROUND: Studies including patients with well-established multiple sclerosis (MS) have shown a significant and disability-related reduction in the cervical spinal cord (SC) magnetisation transfer ratio (MTR). OBJECTIVES: The objectives are to (1) assess whether MTR reduction is already measurable in the SC of patients with early relapsing-remitting multiple sclerosis (RRMS) and (2) describe its spatial distribution. METHODS: We included 60 patients with RRMS <12 months and 34 age-matched controls at five centres. Axial T2*w, sagittal T2w, sagittal phase-sensitive inversion recovery (PSIR), 3DT1w, and axial magnetisation transfer (MT) images were acquired from C1 to C7. Lesions were manually labelled and mean MTR values computed both for the whole SC and for normal-appearing SC in different regions of interest. RESULTS: Mean whole SC MTR was significantly lower in patients than controls (33.7 vs 34.9 pu, p = 0.00005), even after excluding lesions (33.9 pu, p = 0.0003). We observed a greater mean reduction in MTR for vertebral levels displaying the highest lesion loads (C2-C4). In the axial plane, we observed a greater mean MTR reduction at the SC periphery and barycentre. CONCLUSION: Cervical SC tissue damage measured using MTR is not restricted to macroscopic lesions in patients with early RRMS and is not homogeneously distributed.

Efficacy of rituximab in refractory RRMS.

OBJECTIVE: To investigate the efficacy of rituximab as rescue therapy in patients with relapsing-remitting multiple sclerosis (RRMS) and persistent disease activity confirmed by magnetic resonance imaging (MRI) despite immunosuppressive disease-modifying therapy (DMT). METHODS: In this observational nationwide retrospective multicenter study, we first identified 351 off-label rituximab-treated patients through a cohort of 15,984 RRMS patients. In this group, we identified patients with disease activity prior to rituximab confirmed by MRI (one or more new T2 lesion and/or gadolinium-enhancing lesion) despite immunosuppressive DMT (fingolimod, natalizumab, or mitoxantrone) with a follow-up after rituximab initiation longer than 6 months. Outcome data were collected from the French Observatory of Multiple Sclerosis (OFSEP) register and medical charts. RESULTS: A total of 50 patients were identified. Median rituximab treatment duration was 1.1 (0.5-6.4) year. Mean annualized relapse rate significantly decreased from 0.8 during last immunosuppressive DMT to 0.18 after rituximab ( p < 0.0001). While 72% of patients showed gadolinium-enhancing lesions on the last MRI performed during last immunosuppressive DMT, 8% of them showed gadolinium-enhancing lesions on the first MRI performed 6.1 (range 1.4-18.4) months after rituximab ( p < 0.0001). CONCLUSION: This study provides level IV evidence that rituximab reduces clinical and MRI disease activity in patients with active RRMS despite immunosuppressive DMT.

Neuraxial analgesia is not associated with an increased risk of post-partum relapses in MS.

BACKGROUND: Obstetrical analgesia remains a matter of controversy because of the fear of neurotoxicity of local anesthetics on demyelinated fibers or their potential relationship with subsequent relapses. OBJECTIVE: To assess the impact of neuraxial analgesia on the risk of relapse during the first 3 months post-partum, with a focus on women who experienced relapses during pregnancy. METHODS: We analyzed data of women followed-up prospectively during their pregnancies and at least 3 months post-partum, collected in the Pregnancy in Multiple Sclerosis (PRIMS) and Prevention of Post-Partum Relapses with Progestin and Estradiol in Multiple Sclerosis (POPARTMUS) studies between 1992-1995 and 2005-2012, respectively. The association of neuraxial analgesia with the occurrence of a post-partum relapse was estimated by logistic regression analysis. RESULTS: A total of 389 women were included, 215 from PRIMS and 174 from POPARTMUS. In total, 156 women (40%) had neuraxial analgesia. Overall, 24% experienced a relapse during pregnancy and 25% in the 3 months post-partum. Women with a pregnancy relapse were more likely to have a post-partum relapse (odds ratio (OR) = 1.83, p = 0.02), independently of the use of neuraxial analgesia. There was no association between neuraxial analgesia and post-partum relapse (OR = 1.08, p = 0.78). CONCLUSION: Neuraxial analgesia was not associated with an increased risk of post-partum relapses, whatever multiple sclerosis (MS) activity during pregnancy.

MRI features of demyelinating disease associated with anti-MOG antibodies in adults.

The spectrum of Myelin Oligodendrocytes Glycoprotein (MOG) antibody disease constitutes a recently described challenging entity, referring to a relatively new spectrum of autoimmune disorders with antibodies against MOG predominantly involving the optic nerve and spinal cord. The purpose of this article is to describe MRI features of MOG-AD involvement in the optic nerves, spinal cord and the brain of adults.

Matrix metalloproteinase 9 is decreased in natalizumab-treated multiple sclerosis patients at risk for progressive multifocal leukoencephalopathy.

OBJECTIVE: To identify biomarkers associated with the development of progressive multifocal leukoencephalopathy (PML) in multiple sclerosis (MS) patients treated with natalizumab (NTZ). METHODS: Relapsing-remitting MS patients who developed PML under NTZ therapy (pre-PML) and non-PML NTZ-treated patients (NTZ-ctr) were included in the study. Cryopreserved peripheral blood mononuclear cells and serum samples collected at baseline, at 1- and 2-year treated time points, and during PML were analyzed for gene expression by RNA sequencing and for serum protein levels by Luminex and enzyme-linked immunosorbent assays, respectively. RESULTS: Among top differentially expressed genes in the RNA sequencing between pre-PML and NTZ-ctr patients, pathway analysis revealed a high representation of genes belonging to the following categories: proangiogenic factors (MMP9, VEGFA), chemokines (CXCL1, CXCL5, IL8, CCL2), cytokines (IL1B, IFNG), and plasminogen- and coagulation-related molecules (SERPINB2, PLAU, PLAUR, TFPI, THBD). Serum protein levels for these candidates were measured in a 2-step manner in a screening cohort and a validation cohort of pre-PML and NTZ-ctr patients. Only matrix metalloproteinase 9 (MMP9) was validated; in pre-PML patients, MMP9 protein levels were significantly reduced at baseline compared with NTZ-ctr patients, and levels remained lower at later time points during NTZ treatment. INTERPRETATION: The results from this study suggest that the proangiogenic factor MMP9 may play a role as a biomarker associated with the development of PML in MS patients treated with NTZ. Ann Neurol 2017;82:186-195.

Late-onset neutropenia and neurological relapse, during long-term rituximab therapy in myelin oligodendrocyte glycoprotein-antibody spectrum disorder.

Late-onset neutropenia after rituximab therapy (LONART) is defined as a fall in the absolute neutrophil count below 500/mm3 at least 3 weeks after rituximab infusion, in the absence of any other explanation. LONART is rare during dysimmune conditions but can be life-threatening. We report on two patients with LONART and associated neurological relapse occurring in myelin oligodendrocyte glycoprotein (MOG)-antibody spectrum disorders. Rituximab was reintroduced in one patient, while the second patient was switched to tocilizumab. LONART can occur during anti-MOG spectrum disorders. Neurologists should be aware of this rare and treatable complication. Regular monitoring of blood cell counts is needed, and patients should be informed of the need to consult their physician if symptoms of infection appear.

Neuromyelitis optica spectrum disorder mimicking extensive leukodystrophy.

Brain MRI was originally considered to appear normal in neuromyelitis optica spectrum disorders (NMO-SD). Typical brain lesions are now well described and have been integrated in the latest revision of NMO-SD criteria, but the NMO-SD MRI pattern remains not yet comprehensive. We report here extensive white matter lesions (EWML) mimicking leukodystrophy in a 50-year-old woman with long-lasting anti-AQP4+ NMO-SD. We suggest that EWML could be a possible brain MRI presentation of NMO-SD patients.

Risk of autoimmune diseases and human papilloma virus (HPV) vaccines: Six years of case-referent surveillance.

BACKGROUND: Safety of HPV vaccines is still in question due to reports of autoimmune diseases (ADs) following HPV immunization. OBJECTIVES: To assess the risk of ADs associated with HPV vaccination of female adolescents/young adults in France. METHODS: Systematic prospective case-referent study conducted to assess the risks associated with real-life use of HPV vaccines. Cases were female 11-25 years old with incident ADs [central demyelination/multiple sclerosis (CD/MS), connective tissue disease (CTD), Guillain-Barré syndrome (GBS), type-1 diabetes (T1D), autoimmune thyroiditis (AT), and idiopathic thrombocytopenic purpura (ITP)]. Cases were consecutively and prospectively identified at specialized centers across France (2008-2014) and individually matched by age and place of residence to referents recruited in general practice. Risk was computed using multivariate conditional logistic regression models adjusted for family history of ADs, living in France (north/south), co-medications and co-vaccinations. RESULTS: With a total of 478 definite cases matched to 1869 referents, all ADs combined were negatively associated to HPV vaccination with an adjusted odds ratio of 0.58 (95% confidence interval: 0.41-0.83). Similar results were obtained for CD/MS, AT, CT, and T1D, the last two not reaching statistical significance. No association was found for ITP and GBS. Sensitivity analyses combining definite and possible cases with secondary time window showed similar results. CONCLUSION: Exposure to HPV vaccines was not associated with an increased risk of ADs within the time period studied. Results were robust to case definitions and time windows of exposure. Continued active surveillance is needed to confirm this finding for individual ADs.

Effectiveness of mycophenolate mofetil as first-line therapy in AQP4-IgG, MOG-IgG, and seronegative neuromyelitis optica spectrum disorders.

OBJECTIVE: To evaluate the effectiveness and tolerance of mycophenolate mofetil (MMF) as a first-line treatment in neuromyelitis optica spectrum disorder (NMOSD). METHODS: In all, 67 NMOSD patients treated by MMF as first-line therapy, from the NOMADMUS cohort were included. A total of 65 fulfilled 2015 NMOSD criteria, and 5 were myelin oligodendrocyte glycoprotein (MOG)-immunoglobulin G (IgG) positive. Effectiveness was evaluated on percentage of patients continuing MMF, percentage of patients free of relapse, pre- and post-treatment change in the annualized relapse rate (ARR), and Expanded Disability Status Scale (EDSS). RESULTS: Among 67 patients, 40 (59.7%) continued treatment till last follow-up. A total of 33 (49.3%) were relapse-free. The median ARR decreased from one pre-treatment to zero post-treatment. Of 53 patients with complete EDSS data, the score improved or stabilized in 44 (83%; p < 0.05). Effectiveness was observed in aquaporin-4 (AQP4)-IgG (57.8% continued treatment, 46.7% relapse-free), MOG-IgG (3/5 continued treatment, 4/5 relapse-free), and seronegative NMOSD (64.7% continued treatment, 61.3% relapse-free). In 16 patients with associated steroids, 13 (81.2%) continued MMF till last follow-up versus 15 of 28 (53.6%) in the non-steroid group. Nine patients discontinued treatment for tolerability purpose. CONCLUSION: MMF showed effectiveness and good tolerability as a first-line therapy in NMOSD, whatever the AQP4-IgG status. Concomitant use of oral steroids at start could limit the risk of treatment failure.

Assessment of a program to encourage the multidisciplinary management of urinary disorders in multiple sclerosis.

AIMS: Urinary disorders (UD) secondary to multiple sclerosis (MS) are common and can be responsible for complications. Since 2004, we organized in our region their management through a neuro-urological activity and a care network that established and distributed an algorithm for screening and first line care. The objective was to assess the effects of this organization on the management of UD and its impact for patients. METHODS: Between January 2004 and December 2009, 328 patients were seen in neuro-urological consultation. The data of a group of 168 patients consulting during the deployment of our organization (before January 2007: group 1) were compared to those of 160 patients taken when the organization was well established (from January 2007: group 2). In parallel, the modification of the prescription rate of the first-line examination patients was evaluated. RESULTS: The two groups were significantly different concerning age, duration of MS, EDSS score (Group 1 vs. Group 2 respectively 51.6 ± 12.6 vs. 48 ± 11.8 years, P = 0.008; 19 ± 9.7 vs. 13.8 ± 10.5 years, P < 0.0001; 5.8 ±2.0 vs. 5.1 ± 2.1, P = 0.008). The occurrence of urinary complications in group 1 was more frequent than in group 2 (66.3% vs. 40%, P < 0.0001). The rate of first-line examinations rose from 1/16 patient seen in January 2006 to 9/12 patients in January 2008. CONCLUSION: The multidisciplinary management of UD in MS led to patients being cared for sooner in the evolution of MS, with fewer complications and to an improvement in the rate of prescription of first-line examinations. Neurourol. Urodynam. 36:706-709, 2017. © 2016 Wiley Periodicals, Inc.

A pharmacogenetic study implicates SLC9a9 in multiple sclerosis disease activity.

OBJECTIVE: A proportion of multiple sclerosis (MS) patients experience disease activity despite treatment. The early identification of the most effective drug is critical to impact long-term outcome and to move toward a personalized approach. The aim of the present study is to identify biomarkers for further clinical development and to yield insights into the pathophysiology of disease activity. METHODS: We performed a genome-wide association study in interferon-ß (IFNß)-treated MS patients followed by validation in 3 independent cohorts. The role of the validated variant was examined in several RNA data sets, and the function of the presumed target gene was explored using an RNA interference approach in primary T cells in vitro. RESULTS: We found an association between rs9828519(G) and nonresponse to IFNß (pdiscovery = 4.43 × 10(-8)) and confirmed it in a meta-analysis across 3 replication data sets (preplication = 7.78 × 10(-4)). Only 1 gene is found in the linkage disequilibrium block containing rs9828519: SLC9A9. Exploring the function of this gene, we see that SLC9A9 mRNA expression is diminished in MS subjects who are more likely to have relapses. Moreover, SLC9A9 knockdown in T cells in vitro leads an increase in expression of IFNγ, which is a proinflammatory molecule. INTERPRETATION: This study identifies and validates the role of rs9828519, an intronic variant in SLC9A9, in IFNß-treated subjects, demonstrating a successful pharmacogenetic screen in MS. Functional characterization suggests that SLC9A9, an Na(+) -H(+) exchanger found in endosomes, appears to influence the differentiation of T cells to a proinflammatory fate and may have a broader role in MS disease activity, outside of IFNß treatment.

Antibodies to myelin oligodendrocyte glycoprotein in aquaporin 4 antibody seronegative longitudinally extensive transverse myelitis: Clinical and prognostic implications.

OBJECTIVE: We aimed to investigate the frequency and clinical significance of antibodies to myelin oligodendrocyte glycoprotein (MOG-abs) in patients who presented with a first episode of seronegative aquaporin 4 antibody (AQP4-ab) longitudinally extensive transverse myelitis (LETM). METHODS: Epidemiological, clinical, and paraclinical data of 56 patients from three European centres were analysed. Patients were retrospectively tested for MOG-abs and AQP4-abs, by cell-based assays. FINDINGS: Thirteen (23.2%) patients were MOG-ab positive. Among the 56 patients, six (10.7%) converted to neuromyelitis optica (NMO), one (1.8%) to multiple sclerosis (MS), nine (16.1%) had recurrent LETM, and 40 (71.4%) remained as monophasic LETM. Compared with seronegative patients, those with MOG-abs were younger (median: 32.5 vs 44 years; p=0.007), had cerebrospinal fluid pleocytosis more frequently (94% vs 45%, p=0.003) and had better outcome (median Expanded Disability Status Scale (EDSS) 2.0 vs 3.0, p=0.027). MOG-ab positive patients also showed an increase risk of optic neuritis relapse and NMO conversion (p=0.010). CONCLUSION: Patients with MOG-abs in AQP4-ab seronegative LETM have clinical distinctive features, higher risk of optic neuritis relapses, and better outcome than patients seronegative.

PML risk stratification using anti-JCV antibody index and L-selectin.

BACKGROUND: Natalizumab treatment is associated with progressive multifocal leukoencephalopathy (PML) development. Treatment duration, prior immunosuppressant use, and JCV serostatus are currently used for risk stratification, but PML incidence stays high. Anti-JCV antibody index and L-selectin (CD62L) have been proposed as additional risk stratification parameters. OBJECTIVE: This study aimed at verifying and integrating both parameters into one algorithm for risk stratification. METHODS: Multicentric, international cohorts of natalizumab-treated MS patients were assessed for JCV index (1921 control patients and nine pre-PML patients) and CD62L (1410 control patients and 17 pre-PML patients). RESULTS: CD62L values correlate with JCV serostatus, as well as JCV index values. Low CD62L in natalizumab-treated patients was confirmed and validated as a biomarker for PML risk with the risk factor "CD62L low" increasing a patient's relative risk 55-fold (p < 0.0001). Validation efforts established 86% sensitivity/91% specificity for CD62L and 100% sensitivity/59% specificity for JCV index as predictors of PML. Using both parameters identified 1.9% of natalizumab-treated patients in the reference center as the risk group. CONCLUSIONS: Both JCV index and CD62L have merit for risk stratification and share a potential biological relationship with implications for general PML etiology. A risk algorithm incorporating both biomarkers could strongly reduce PML incidence.

NLRP3 inflammasome is associated with the response to IFN-ß in patients with multiple sclerosis.

Evidence exists for a potential modulation of inflammasome activity by interferon beta. Here, we investigated the roles of inflammasomes [absent in melanoma 2 (AIM2); NLR family, CARD domain containing 4 (NLRC4); NLR family, pyrin domain containing 1 and 3 (NLRP1 and NLRP3)] and related cytokines (IL1B, IL10, IL18) in the response to interferon beta in patients with relapsing-remitting multiple sclerosis. Ninety-seven patients treated with interferon beta were classified into responders and non-responders according to clinical criteria after 24 months and clinical-radiological criteria after 12 months of treatment. Messenger RNA expression levels of inflammasomes and cytokines were determined by real-time polymerase chain reaction in peripheral blood mononuclear cells collected before treatment with interferon beta. In a subgroup of patients, NLRP3 and IL1B expression was also determined after 3 months (n = 32) and 12 months (n = 20) of interferon beta treatment. A polymorphism located in the NLRP3 gene, rs35829419, was genotyped in 789 multiple sclerosis patients treated with interferon beta. Baseline mRNA expression levels for NLRP3 and IL1B were increased in peripheral blood mononuclear cells from non-responders compared to responders classified according to clinical criteria after 24 months (P = 0.02 and P = 0.001, respectively). No significant differences were observed for other inflammasomes and related cytokines. Differences in NLRP3 and IL1B expression remained significant following a clinical-radiological classification after 12 months (P = 0.007 and P = 0.02, respectively). After treatment with interferon beta, NLRP3 and IL1B expression was increased in responders but unchanged in non-responders. A trend for association was observed between rs35829419 and interferon beta response (pM-H = 0.08). These results point to a role of the NLRP3 inflammasome and its related cytokine IL1B in the response to interferon beta in patients with relapsing-remitting multiple sclerosis.