INS;croRNA, a critical regulator of an autoimmune demyelination

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Abstracts / Journal of the Neurological Sciences 333 (2013) e358–e421

respectively; in Brazil, of the 1235 patients (69% Caucasians and 29% African descendants) the frequency of MS was 62.5% and NMO 13%; in Paraguay, of the 164 patients (70% Caucasians and 30% Mestizos) the frequencies were 79% MS and 7% NMO; and in Venezuela, of the 89 patients (64% Mestizos, 18% Caucasians and 9% African descendants), 47% MS and 33% NMO. Conclusion: In the countries with the lowest number of Caucasians and greater population mixing, Mestizos and Afro descendents, as Venezuela and Brazil the NMO frequency is higher, reinforcing the observation recognized of the ethnic distribution of neuromyelitis optic among non Caucasian populations from tropical regions. doi:10.1016/j.jns.2013.07.1317

Abstract — WCN 2013 No: 2936 Topic: 6 — MS & Demyelinating Diseases Understanding mechanisms of axonal loss in non-optic neuritis eyes of MS patients A. Klistornera,b, P. Sriramb, N. Vootakuruc, C. Wangc, M. Barnettc, R. Garrickd, J. Parratte, N. Levinf, A. Bickf, L. Mastersc, S.L. Grahamb, C. Yiannikasc. aSave Sight Institute, Australia; bMacquarie University, Australia; cSydney University, Australia; dSt Vincent's Hospital, Australia; e North Shore Hospital, Sydney, NSW, Australia; fHebrew University, Jerusalem, Israel Background: Axonal injury is a major cause of disability in MS. Numerous studies demonstrated loss of retinal ganglion cell axons in MS patients with no history of ON. However, the pathological basis of this loss at present is not clear. Objective: To investigate links between loss of RGC axons and MSrelated injury of anterior (outer retina) and posterior (optic tract and optic radiation) parts of the visual pathway. Patients and methods: Thickness of temporal RNFL was analysed in 55 RRMS with no history of ON at least in one eye. Integrity of the outerretina was assessed using electroretinogram (ERG) and measurements of outer retinal layers. Latency of the mfVEP indicated previous inflammatory demyelination along the posterior visual pathway. FLAIR T2 optic radiation lesions were identified using tractography. Results: There was significant delay of photopic ERG b-wave, which correlated with loss of tRNFL. Significant reduction of tRNFL was also observed in patients who displayed functional (mfVEP delay or abnormal DTI) or structural (lesions) evidence of previous OR damage. No indication of OT lesions was found. Linear regression analysis explained 50% of the tRNFL variability. However, while contribution of ERG delay was significant, estimated predictive power of OR lesions was by far the largest. Conclusion: Study result suggests dual nature of RGC axonal loss in NON eyes of MS patients. While strong tract-specific relationship between loss of tRNFL and OR damage advocates retrograde transneuronal process as a major factor, significant association of tRNFL thickness with ERG delay also implicates primary retinal pathology. doi:10.1016/j.jns.2013.07.1318

Abstract — WCN 2013 No: 2939 Topic: 6 — MS & Demyelinating Diseases Clinical consequences of persistently high-titer neutralizing antibodies in patients with multiple sclerosis — Results from the German reference lab T. Menge, G. Hartung-Neumann, A. Hess, H.-P. Hartung, B.C. Kieseier. Neurology, Heinrich-Heine-University, Düsseldorf, Germany

Background: In patients with multiple sclerosis (MS) treated with interferon beta (IFNb), neutralizing antibodies (NAbs) may develop. If high-titer (ht) and persistent, these may limit the bioavailability of IFNb and its clinical benefits. Objective: To report NAb prevalences from the German reference lab identifying patients with persistent htNAbs against IFNb and to inquire about subsequent clinical decision making. Methods: Serum samples sent in nationwide between January 2008 and June 2010 for NABs testing were subjected to ELISA screening for binding antibodies and to a luciferase reporter gene assay for quantitative detection of NAbs. Treating physicians of patients with htNABs (N100 TRU/mL) detected in two independent samples were contacted by mail to provide follow-up information by means of a standardized questionnaire. Results: 1990 serum samples were screened for the presence of NAbs. NAbs and htNAbs were detectable in 22% and 4.8% of samples, respectively. Follow-up samples were provided in 11% and demonstrated consistent serostatus in 58%. NAbs were lowest with IFNb-1a i.m. compared to IFNb-1b s.c. and IFNb-1a s.c. (8.6% vs. 28.1% vs. 40.5%; p b 0.0001, chi-square). 25 patients with persistent htNAbs were identified, of which 20 questionnaires were returned; therapy was amended in 16 patients: 75% were switched to glatiramer acetate (GA), 18.7% were escalated to more potent therapies. Conclusions: The overall prevalence of persistent htNAbs is low. When detected, the majority of treating neurologists opted to switch to GA rather than to continue IFNb or to escalate therapy.

doi:10.1016/j.jns.2013.07.1319

Abstract — WCN 2013 No: 2763 Topic: 6 — MS & Demyelinating Diseases MicroRNA, a critical regulator of an autoimmune demyelination M.P. Mycko, M. Cichalewska, M. Mariasiewicz, B. Sliwinska, H. Cwiklinska, K.W. Selmaj. Department of Neurology, Laboratory of Neuroimmunology, Medical University of Lodz, Lodz, Poland Background: MicroRNAs (miRNA) are short, non-coding RNAs regulating expression of classical genes and emerge as a mechanism controlling immune reactions. However, a detailed role of miRNA in regulation of autoimmunity remains unclear. Objective: To analyze microRNA involvement during the development of autoimmune demyelination. Material and methods: We utilized an animal model of multiple sclerosis — experimental autoimmune encephalomyelitis (EAE). Sorted T helper (Th) cell from lymph nodes of C57Bl/6 mice immunized with MOG peptide 35–55 as well as from MOG-TCR transgenic mice were used for the analyses. We have performed a global miRNA profiling as well as individual miRNA assays during the development of the Th cell autoimmune recognition of myelin antigen. Results: We have found a specific expression of miRNA in Th cell highlighting three miRNA to be upregulated: mmu-miR155, mmumiR21 and mmu-miR301a. Mmu-miR155, mmu-miR21 and mmumiR301a were also upregulated in brain infiltrating cells isolated from EAE. The changes in the above miRNA correlated with both in vitro and in vivo Th17 differentiation. Use of specific miRNA antagonists revealed that miR-301a contributed to the development of the Th17 subset via targeting of the interleukin 6/23–STAT3 pathway. The analysis of MS patients (n = 48) and controls (n = 36) revealed that stimulation of peripheral blood T cells lead to significantly higher overproduction of miR-301a in MS patients v. controls (2.9 v. 0.7 fold induction, p b 0.015).

Abstracts / Journal of the Neurological Sciences 333 (2013) e358–e421

Conclusion: We have identified a previously unknown critical role of miR-301a in regulation of autoimmune demyelination and development of autoreactive subset of Th cells. doi:10.1016/j.jns.2013.07.1320

Abstract — WCN 2013 No: 2910 Topic: 6 — MS & Demyelinating Diseases Fingolimod (FTY720) oral for the treatment of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP): Study design of the phase 3 FORCIDP trial R. Hughesa, M. Dalakasb, N. Latovc, J.-M. Légerd, I. Merkiese,f, E. Nobile-Oraziog, C. Agoropoulouh, D.A. Häringh, L. Zhang-Aubersonh, P. von Rosenstielh, H.-P. Hartungi. aNational Hospital for Neurology and Neurosurgery, London, UK; bDepartment of Neurology, University of Athens Medical School, Athens, Greece; cWeill Cornell Medical College, New York, NY, USA; dBoulevard de l'Hopital, Paris, France; eSpaarne Ziekenhuis, Hoofddrop, The Netherlands; fMaastricht University Medical Center, Maastricht The Netherlands; gInstituto Clinico Humanitas, Rozzano Italy; hNovartis Pharma AG, Basel Switzerland; iDepartment of Neurology, Heinrich-Heine-University, Düsseldorf, Germany Background: CIDP is a chronic sensorimotor neuropathy causing significant disability. Fingolimod, a sphingosine-1-phosphate receptor modulator, completely prevented paraparesis, significantly decreased T-/B-cell, macrophage infiltration and demyelination of sciatic nerves in experimental autoimmune neuritis. Objective: Evaluate efficacy in delaying disability progression (≥1 point increase from baseline on the adjusted Inflammatory Neuropathy Cause and Treatment (INCAT) disability scale), safety and tolerability of oral fingolimod 0.5 mg daily compared with placebo in CIDP patients. Patients and methods: FORCIDP study is a double-blind, randomised, multi-centre, placebo-controlled, parallel-group study in adult patients with CIDP and history of disease activity upon discontinuation of CIDP therapy. Patients are randomised (1:1) to either fingolimod 0.5 mg or placebo. The primary outcome is the time-to-first disability progression. The study has N90% power at a one-sided 2.5% significance level to detect a hazard ratio of 0.51; 111 events are anticipated in approximately 156– 200 randomised participants for the final analysis. Participants fulfilling the disability event criterion will discontinue the study medication immediately and complete the study with a standard CIDP treatment. A group-sequential design with one planned interim analysis after 50 events for futility stopping (one-sided stratified log-rank test; futility boundary at p-value ≥ 0.2282) will be used to prevent patients from prolonged exposure to potentially inefficacious study drug. The study otherwise will continue until the required number of events are observed, or up to a maximum of three years from the trial initiation. Results and conclusion: This study will provide evidence whether fingolimod can delay disability progression in patients with CIDP. doi:10.1016/j.jns.2013.07.1321

Abstract — WCN 2013 No: 2918 Topic: 6 — MS & Demyelinating Diseases Discontinuation of natalizumab — Reasons and implications S. Salhofer-Polanyi, A. Baumgartner, F. Leutmezer. Department of Neurology, Medical University of Vienna, Vienna, Austria Background: Long-term treatment of multiple sclerosis with natalizumab is limited due to the risk of progressive multifocal leucencephalopathy.

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Objective: To evaluate reasons of treatment discontinuation and its effect on disease activity within 12 months after cessation of natalizumab. Methods: We retrospectively analyzed data of 131 MS patients who discontinued natalizumab between 2007 and 2012. Patient data was taken from the Austrian natalizumab registry and completed by a questionnaire sent to 19 MS centers. Patients with data available both from the registry and the questionnaire were included. Results: Duration of therapy exceeded 3 years in only 15.3%, while mean duration was 24.3 months (range 4 months–56 months). Most frequent reasons for discontinuation were: disease activity (14%), seropositivity for JC-virus (14.7%), and long-term treatment in JCVseropositive patients (14.7%). Only 103 patients again started MS specific-therapies, 15 of them natalizumab. Annualized relapse rate (ARR) increased from 0.53 ± 0.97 on natalizumab to 1.2 (±1.44) postnatalizumab (p b 0.001). Compared to pre-treatment levels (mean ARR 2.1), ARR after cessation was significantly lower (p b 0.001). Disease activity after 12 months exceeded pre-treatment levels in 14%, and was the same in 16.5% and lower in 69.4% of patients. At the beginning and end of natalizumab median EDSS was 3.5 and 3.0, respectively, and 12 months after cessation it increased to 3.5 (p = 0.028). Conclusion: We could not find a rebound phenomenon within 12 months after cessation of natalizumab. While EDSS remained the same, ARR was significantly lower 12 months after discontinuation as compared to the pre-treatment year. doi:10.1016/j.jns.2013.07.1322

Abstract — WCN 2013 No: 2956 Topic: 6 — MS & Demyelinating Diseases The role of T-cells in the pathogenesis of neuromyelitis optica M. Pohla, N. Kawakamib, J. Bauera, M. Kitica, S. Maderc, J.W. Ellwartd, R. Martinsa, T. Misue, K. Fujiharae, H. Wekerleb, M. Reindlc, H. Lassmanna, M. Bradla. aMedical University Vienna, Center for Brain Research, Vienna, Austria; bMax-Planck-Insitute for Neurobiology, Munich Germany; c Innsbruck Medical University, Department of Neurology, Innsbruck, Austria; dInstitute for Molecular Immunology, GSF-National Research Center for Environment and Health, Munich Germany; eDepartments of Multiple Sclerosis Therapeutics and Neurology, Tohoku University Graduate School of Medicine, Sendai, Japan Neuromyeltis optica (NMO) is a severely disabling, demyelinating inflammatory disease of the central nervous system (CNS). The diagnostic hallmark of NMO is the presence of antibodies in the serum, which are specifically directed against Aquaporin 4 (AQP4), a water channel enriched on astrocytic endfeet at the glia limitans. These antibodies have been shown to be pathogenic. Once inside the CNS, they find their target on the surface of astrocytes, fix complement and initiate the complement mediated destruction of these cells. We have previously shown in our animal-NMO-models that acute lesions with AQP4 loss can form when CNS antigen specific T cells initiate CNS inflammation, whereas no lesions can be induced with AQP4 antibodies only. Furthermore we could see that the antigen specificity had an impact on the speed of lesion formation, peripheral organ affection and recruitment of other inflammatory cells. We found that T cells which produce the largest lesions in AQP4 antibody positive rats were best reactivated within the CNS and produced the most IFN-γ. We then analyzed the effects of IFN-γ on the gene expression by microglia using microarray analysis. IFN-γ treated microglia produced complement factors, downregulated complement inhibitors and upregulated Fcγr, and hence significantly contribute to the complement mediated destruction of astrocytes. doi:10.1016/j.jns.2013.07.1323