Deleterious functional consequences of perfluoroalkyl substances accumulation into the myelin sheath.

Exposure to persistent organic pollutants during the perinatal period is of particular concern because of the potential increased risk of neurological disorders in adulthood. Here we questioned whether exposure to perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) could alter myelin formation and regeneration. First, we show that PFOS, and to a lesser extent PFOA, accumulated into the myelin sheath of postnatal day 21 (p21) mice, whose mothers were exposed to either PFOA or PFOS (20 mg/L) via drinking water during late gestation and lactation, suggesting that accumulation of PFOS into the myelin could interfere with myelin formation and function. In fact, PFOS, but not PFOA, disrupted the generation of oligodendrocytes, the myelin-forming cells of the central nervous system, derived from neural stem cells localised in the subventricular zone of p21 exposed animals. Then, cerebellar slices were transiently demyelinated using lysophosphatidylcholine and remyelination was quantified in the presence of either PFOA or PFOS. Only PFOS impaired remyelination, a deleterious effect rescued by adding thyroid hormone (TH). Similarly to our observation in the mouse, we also showed that PFOS altered remyelination in Xenopus laevis using the Tg(Mbp:GFP-ntr) model of conditional demyelination and measuring, then, the number of oligodendrocytes. The functional consequences of PFOS-impaired remyelination were shown by its effects using a battery of behavioural tests. In sum, our data demonstrate that perinatal PFOS exposure disrupts oligodendrogenesis and myelin function through modulation of TH action. PFOS exposure may exacerbate genetic and environmental susceptibilities underlying myelin disorders, the most frequent being multiple sclerosis.

A randomized double-blind placebo-controlled trial of low-dose interleukin-2 in relapsing-remitting multiple sclerosis.

BACKGROUND: Multiple sclerosis (MS) is associated with regulatory T cells (Tregs) insufficiency while low-dose interleukin-2 (IL2LD) activates Tregs and reduces disease activity in autoimmune diseases. METHODS: We aimed at addressing whether IL2LD improved Tregs from MS patients. MS-IL2 was a single-center double-blind phase-2 study. Thirty patients (mean [SD] age 36.8 years [8.3], 16 female) with relapsing-remitting MS with new MRI lesions within 6 months before inclusion were randomly assigned in a 1:1 ratio to placebo or IL-2 at 1 million IU, daily for 5 days and then fortnightly for 6 months. The primary endpoint was change in Tregs at day-5. RESULTS: Unlike previous trials of IL2LD in more than 20 different autoimmune diseases, Tregs were not expanded at day-5 in IL2LD group, but only at day-15 (median [IQR] fold change from baseline: 1.26 [1.21-1.33] in IL2LD group; 1.01 [0.95-1.05] in placebo group, p < 0.001). At day-5, however, Tregs had acquired an activated phenotype (fold change of CD25 expression in Tregs: 2.17 [1.70-3.55] in IL2LD versus 0.97 [0.86-1.28] in placebo group, p < 0.0001). Regulator/effector T cells ratio remained elevated throughout treatment period in the IL2LD group (p < 0.001). Number of new active brain lesions and of relapses tended to be reduced in IL2LD treated patients, but the difference did not reach significance in this trial not powered to detect clinical efficacy. CONCLUSION: The effect of IL2LD on Tregs in MS patients was modest and delayed, compared to other auto-immune diseases. This, together with findings that Tregs improve remyelination in MS models and recent reports of IL2LD efficacy in amyotrophic lateral sclerosis, warrants larger studies of IL2LD in MS, notably with increased dosages and/or modified modalities of administration. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov: NCT02424396; EU Clinical trials Register: 2014-000088-42.

Microglia-neuron interaction at nodes of Ranvier depends on neuronal activity through potassium release and contributes to remyelination.

Microglia, the resident immune cells of the central nervous system, are key players in healthy brain homeostasis and plasticity. In neurological diseases, such as Multiple Sclerosis, activated microglia either promote tissue damage or favor neuroprotection and myelin regeneration. The mechanisms for microglia-neuron communication remain largely unkown. Here, we identify nodes of Ranvier as a direct site of interaction between microglia and axons, in both mouse and human tissues. Using dynamic imaging, we highlight the preferential interaction of microglial processes with nodes of Ranvier along myelinated fibers. We show that microglia-node interaction is modulated by neuronal activity and associated potassium release, with THIK-1 ensuring their microglial read-out. Altered axonal K+ flux following demyelination impairs the switch towards a pro-regenerative microglia phenotype and decreases remyelination rate. Taken together, these findings identify the node of Ranvier as a major site for microglia-neuron interaction, that may participate in microglia-neuron communication mediating pro-remyelinating effect of microglia after myelin injury.

A comparative evaluation of different neuromyelitis optica spectrum disorder sets of criteria.

BACKGROUND AND PURPOSE: Three different sets of criteria have been proposed for the diagnosis of neuromyelitis optica spectrum disorder (NMOSD). The objective was to compare the specificity, sensitivity and diagnostic accuracy of the three different sets of NMOSD criteria in patients presenting with inflammatory disorders of the central nervous system suggestive of NMOSD. METHODS: For 236 suspected NMOSD patients referred for serum aquaporin-4 immunoglobulin G antibody (AQP4-IgG) testing between 2012 and 2014, the three sets of NMOSD criteria [1999, 2006 NMO criteria and 2015 International Panel for NMO Diagnosis (IPND) criteria] were applied and compared to the final diagnosis. RESULTS: Seventy-six patients fulfilled at least one set of criteria and 28 patients fulfilled all NMOSD sets of criteria. The final diagnosis was NMOSD in 66 cases, multiple sclerosis according to the MacDonald 2010 criteria in 85 cases and another diagnosis in 85 cases. The 2006 NMO criteria have the highest specificity (99%) and the 2015 IPND NMOSD criteria the highest sensitivity (97%). For the 1999, 2006 and 2015 IPND NMOSD criteria, the accuracy was respectively 82%, 87% and 97%. CONCLUSIONS: Our study highlights the limitations of the first set of criteria that include the optico-spinal form of multiple sclerosis. The accuracy of NMOSD diagnostic criteria improved from 1999 to 2015. It confirms the increased performance of the last set of criteria which covers a larger spectrum of clinical presentation. This study raises some concerns for classifying patients with seronegative transverse myelitis or optic neuritis, and myelin oligodendrocyte glycoprotein (MOG) antibody- associated disease.

The cerebrospinal fluid CD4/CD8 ratio and interleukin-6 and -10 levels in neurosarcoidosis: a multicenter, pragmatic, comparative study.

BACKGROUND AND PURPOSE: Neurosarcoidosis is a rare inflammatory disorder of unknown cause. The aim of this study was to evaluate the value of T/B lymphocyte population counts and the concentrations of the cytokines interleukin (IL) 6 and IL-10 in the cerebrospinal fluid (CSF) of neurosarcoidosis patients. METHODS: A retrospective study CSF biomarkers was conducted in patients with neurosarcoidosis who underwent CSF analysis between 2012 and 2017 as well as various control populations. RESULTS: Forty-three patients with neurosarcoidosis, 14 with multiple sclerosis (MS) and 48 with other inflammatory disorders were analyzed. The CSF IL-6 levels were higher in sarcoidosis patients than in MS patients (median 8 vs. 3 pg/ml, P = 0.006). The CSF CD4/CD8 ratio was higher in sarcoidosis patients than in MS patients and in patients with other inflammatory disorders (median 3.18 vs. 2.36 and 2.10, respectively, P = 0.008). The CSF IL-6 level was higher in patients with active neurosarcoidosis than in non-active neurosarcoidosis patients (median 13 vs. 3 pg/ml, P = 0.0005). In patients with neurosarcoidosis, a CSF IL-6 concentration >50 pg/ml was associated with a higher risk of relapse or progression-free survival (hazard ratio 3.60; 95% confidence interval 1.78-23.14). A refractory neurosarcoidosis patient was treated with an anti-IL-6 monoclonal antibody that produced a complete neurological response. CONCLUSIONS: The CSF CD4/CD8 ratio and IL-6 concentration are increased in neurosarcoidosis compared to MS and other inflammatory disorders. A CSF IL-6 concentration >50 pg/ml is associated with relapse or progression of neurosarcoidosis. IL-10 levels may be elevated in neurosarcoidosis.

Impact of an adaptive program for cognitive and emotional deficits (ADACOG program) in multiple sclerosis patients with cognitive impairments.

BACKGROUND: Cognitive impairment is frequent in multiple sclerosis (MS), affecting approximately 40 to 70% of patients. We developed a psycho-educational program (ADACOG program) to allow patients to cope with cognitive deficits. The purpose of this exploratory study was to investigate the impact of the ADACOG program on subjective self-reported cognitive impairments, quality of life, anxiety, depression and self-esteem in MS patients. METHODS: ADACOG program is a psycho-educational program focusing on cognitive and emotional dysfunctions in MS consisting of three modules in small groups lasting two hours every two weeks. Forty-five MS patients with self-reported cognitive impairments and objective cognitive deficits were enrolled consecutively in two groups: (i) the ADACOG group (N=24) and (ii) the control group (N=21). Both groups of patients completed questionnaires evaluating self-reported cognitive impairments (Multiple Sclerosis Neuropsychological Screening Questionnaire), quality of life (Multiple Sclerosis Impact Scale), anxiety and depression (Hospital Anxiety and Depression Scale, HAD) and self-esteem (Rosenberg Scale) at inclusion (M0), one month later (M1) and seven months after inclusion (M7). The evolution of outcomes within ADACOG group and between both groups was analyzed. RESULTS: The analyses within the ADACOG group showed that patients reported better quality of life and fewer anxiety symptoms at M1 compared to M0 (respectively P=0.03 and P=0,04). Moreover, patients presented less subjective self-reported cognitive deficits at M7 compared to M0 (P=0.003). Score evolution for HAD depression and self-esteem were not significant within the ADACOG group. The change M1-M0 for MSIS-29 and HAD anxiety scores was significantly different between both groups (respectively P=0.04 and P=0.008), with improvement of quality of life and anxiety in the ADACOG group. The evolution of scores between groups was not significant for the other outcomes. DISCUSSION: This study showed a small effect of a psycho-educational program focusing on cognitive and emotional disorders in MS patients with subjective self-reported cognitive deficits and objective cognitive deficits. Interest of psycho-education focusing on cognition in MS patients is discussed.

ECTRIMS/EAN guideline on the pharmacological treatment of people with multiple sclerosis.

BACKGROUND AND PURPOSE: Multiple sclerosis (MS) is a complex disease of the central nervous system. As new drugs are becoming available, knowledge on diagnosis and treatment must continuously evolve. There is therefore a need for a reference tool compiling current data on benefit and safety, to aid professionals in treatment decisions and use of resources across Europe. The European Committee of Treatment and Research in Multiple Sclerosis (ECTRIMS) and the European Academy of Neurology (EAN) have joined forces to meet this need. The objective was to develop an evidence-based clinical practice guideline for the pharmacological treatment of people with MS to guide healthcare professionals in the decision-making process. METHODS: This guideline has been developed using the GRADE methodology and following the recently updated EAN recommendations for guideline development. Clinical questions were formulated in PICO format (patient, intervention, comparator, outcome) and outcomes were prioritized according to their relevance to clinical practice. An exhaustive literature search up to December 2016 was performed for each question and the evidence is presented narratively and, when possible, combined in a meta-analysis using a random-effects model. The quality of evidence for each outcome was rated into four categories - very high, high, low and very low - according to the risk of bias. GRADE evidence profiles were created using GRADEprofiler (GRADEpro) software (Version 3.6). The recommendations with assigned strength (strong, weak) were formulated based on the quality of evidence and the risk-benefit balance. Consensus between the panellists was reached by use of the modified nominal group technique. RESULTS: A total of 10 questions have been agreed, encompassing treatment efficacy, response criteria, strategies to address suboptimal response and safety concerns and treatment strategies in MS and pregnancy. The guideline takes into account all disease-modifying drugs approved by the European Medicine Agency at the time of publication. A total of 20 recommendations were agreed by the guideline working group members after three rounds of consensus.

Patterns of Objective and Subjective Burden of Informal Caregivers in Multiple Sclerosis.

BACKGROUND: Home care for patients with Multiple Sclerosis (MS) relies largely on informal caregivers (ICs). Methods. We assessed ICs objective burden (Resource Utilization in Dementia measuring informal care time (ICT)) and ICs subjective burden (Zarit Burden Inventory (ZBI)). RESULTS: ICs (N = 99) were spouses (70%), mean age 52 years, assisting disabled patients with a mean EDSS (Expanded Disability Status Scale) of 5.5, with executive dysfunction (mean DEX (Dysexecutive questionnaire) of 25) and a duration of MS ranging from 1 to 44 years. OBJECTIVE: burden was high (mean ICT = 6.5 hours/day), mostly consisting of supervision time. Subjective burden was moderate (mean ZBI = 27.3). Multivariate analyses showed that both burdens were positively correlated with higher levels of EDSS and DEX, whereas coresidency and IC's female gender correlated with objective burden only and IC's poor mental health status with subjective burden only. When considering MS aggressiveness, it appeared that both burdens were not correlated with a higher duration of MS but rather increased for patients with severe and early dysexecutive function and for patients classified as fast progressors according to the Multiple Sclerosis Severity Score. CONCLUSION: Evaluation of MS disability course and IC's personal situation is crucial to understand the burden process and to implement adequate interventions in MS.

A prospective observational post-marketing study of natalizumab-treated multiple sclerosis patients: clinical, radiological and biological features and adverse events. The BIONAT cohort.

BACKGROUND AND PURPOSE: BIONAT is a French multicentric phase IV study of natalizumab (NTZ)-treated relapsing-remitting multiple sclerosis (MS) patients. The purpose of this study was to collect clinical, radiological and biological data on 1204 patients starting NTZ, and to evaluate the clinical/radiological response to NTZ after 2 years of treatment. METHODS: Patients starting NTZ at 18 French MS centres since June 2007 were included. Good response to NTZ was defined by the absence of clinical and radiological activity. Data analysed in this first report on the BIONAT study focus on patients who started NTZ at least 2 years ago (n = 793; BIONAT2Y ). RESULTS: NTZ was discontinued in 17.78% of BIONAT2Y. The proportion of patients without combined disease activity was 45.59% during the first two successive years of treatment. Systematic dosage of anti-NTZantibodies (Abs) detected only two supplementary patients with anti-NTZ Abs compared with strict application of recommendations. A significant decrease of IgG,M concentrations at 2 years of treatment was found. CONCLUSIONS: The efficacy of NTZ therapy on relapsing-remitting MS in a real life setting is confirmed in the BIONAT cohort. The next step will be the identification of biomarkers predicting response to NTZ therapy and adverse events.

Dramatic worsening following plasma exchange in severe post-natalizumab withdrawal multiple sclerosis relapse.

We report the case of a young woman with multiple sclerosis who discontinued natalizumab twice and experienced a severe relapse following each natalizumab withdrawal. The first relapse was successfully treated by intravenous methylprednisolone (IVMP). In contrast the second relapse was unresponsive to IVMP. Subsequent treatment by plasma exchanges (PLEX) was followed by a dramatic neurological worsening. This case suggests that PLEX after natalizumab discontinuation may increase relapse severity.

Intravascular lymphoma mimicking a Vogt-Koyanagi-Harada disease.

PURPOSE: To report a case of intravascular lymphoma (IVL) mimicking a Vogt-Koyanagi-Harada disease (VKH). DESIGN: Case report. METHODS: A 38-year-old man was referred for blurred vision, headache, and hearing loss. Examination demonstrated vitritis and subretinal detachments in each eye. Cerebral fluid analysis showed lymphocytic meningitis. Cerebral MRI was normal. A diagnosis of VKH disease was made. RESULTS: Steroid treatment was introduced, after which all symptoms disappeared. Six months later, the patient returned with paraplegia and confusion. Cerebral MRI revealed hypodense periventricular lesions. A stereotaxic biopsy confirmed the diagnosis of IVL. The patient died a few months later. CONCLUSION: IVL may have many revealing aspects, including ophthalmologic symptoms.

Effect of glatiramer acetate on conversion to clinically definite multiple sclerosis in patients with clinically isolated syndrome (PreCISe study): a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Glatiramer acetate, approved for the treatment of relapsing-remitting multiple sclerosis, reduces relapses and disease activity and burden monitored by MRI. We assessed the efficacy of early treatment with glatiramer acetate in delaying onset of clinically definite multiple sclerosis. METHODS: In this randomised, double-blind trial, undertaken in 80 sites in 16 countries, 481 patients presenting with a clinically isolated syndrome with unifocal manifestation, and two or more T2-weighted brain lesions measuring 6 mm or more, were randomly assigned to receive either subcutaneous glatiramer acetate 20 mg per day (n=243) or placebo (n=238) for up to 36 months, unless they converted to clinically definite multiple sclerosis. The randomisation scheme used SAS-based blocks stratified by centre, and patients and all personnel were masked to treatment assignment. The primary endpoint was time to clinically definite multiple sclerosis, based on a second clinical attack. Analysis was by intention to treat. A preplanned interim analysis was done for data accumulated from 81% of the 3-year study exposure. This study was registered with ClinicalTrials.gov, number NCT00666224. FINDINGS: All randomly assigned participants were analysed for the primary outcome. Glatiramer acetate reduced the risk of developing clinically definite multiple sclerosis by 45% compared with placebo (hazard ratio 0.55, 95% CI 0.40-0.77; p=0.0005). The time for 25% of patients to convert to clinically definite disease was prolonged by 115%, from 336 days for placebo to 722 days for glatiramer acetate. The most common adverse events in the glatiramer acetate group were injection-site reactions (135 [56%] glatiramer acetate vs 56 [24%] placebo) and immediate post-injection reactions (47 [19%] vs 12 [5%]). INTERPRETATION: Early treatment with glatiramer acetate is efficacious in delaying conversion to clinically definite multiple sclerosis in patients presenting with clinically isolated syndrome and brain lesions detected by MRI. FUNDING: Teva Pharmaceutical Industries, Israel.

Leukoencephalopathies associated with inborn errors of metabolism in adults.

The discovery of a leukoencephalopathy is a frequent situation in neurological practice and the diagnostic approach is often difficult given the numerous possible aetiologies, which include multiple acquired causes and genetic diseases including inborn errors of metabolism (IEMs). It is now clear that IEMs can have their clinical onset from early infancy until late adulthood. These diseases are particularly important to recognize because specific treatments often exist. In this review, illustrated by personal observations, we give an overview of late-onset leukoencephalopathies caused by IEMs.

Age at onset determines the occurrence of the progressive phase of multiple sclerosis.

We investigated the influence of age at disease onset on timing of the progressive phase in 957 patients with multiple sclerosis (MS). Age at onset powerfully predicts the probability of developing a primary progressive form of the disease. Moreover, age at onset strongly determines the time to conversion to secondary progression for patients presenting with a relapsing form. This suggests that age at onset strongly influences the neurodegenerative component of MS.

Nodal, paranodal and juxtaparanodal axonal proteins during demyelination and remyelination in multiple sclerosis.

Saltatory conduction in myelinated fibres depends on the specific molecular organization of highly specialized axonal domains at the node of Ranvier, the paranodal and the juxtaparanodal regions. Voltage-gated sodium channels (Na(v)) have been shown to be deployed along the naked demyelinated axon in experimental models of CNS demyelination and in multiple sclerosis lesions. Little is known about aggregation of nodal, paranodal and juxtaparanodal constituents during the repair process. We analysed by immunohistochemistry on free-floating sections from multiple sclerosis brains the expression and distribution of nodal (Na(v) channels), paranodal (paranodin/Caspr) and juxtaparanodal (K(v) channels and Caspr2) molecules in demyelinated and remyelinated lesions. Whereas in demyelinated lesions, paranodal and juxtaparanodal proteins are diffusely distributed on denuded axons, the distribution of Na(v) channels is heterogeneous, with a diffuse immunoreactivity but also few broad Na(v) channel aggregates in all demyelinated lesions. In contrast to the demyelinated plaques, all remyelinated lesions are characterized by the detection of aggregates of Na(v) channels, paranodin/Caspr, K(v) channels and Caspr2. Our data suggest that these aggregates precede remyelination, and that Na(v) channel aggregation is the initial event, followed by aggregation of paranodal and then juxtaparanodal axonal proteins. Remyelination takes place in multiple sclerosis tissue but myelin repair is often incomplete, and the reasons for this remyelination deficit are many. We suggest that a defect of Na(v) channel aggregation might be involved in the remyelination failure in demyelinated lesions with spared axons and oligodendroglial cells.