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Dive into the research topics where Mark S. Freedman is active.

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Featured researches published by Mark S. Freedman.


Annals of Neurology | 2009

Rituximab in patients with primary progressive multiple sclerosis: Results of a randomized double-blind placebo-controlled multicenter trial†

Kathleen Hawker; Paul O'Connor; Mark S. Freedman; Peter A. Calabresi; Jack P. Antel; Jack H. Simon; Stephen L. Hauser; Emmanuelle Waubant; Timothy Vollmer; Hillel Panitch; Jiameng Zhang; Peter Chin; Craig H. Smith

Rituximab, a monoclonal antibody selectively depleting CD20+ B cells, has demonstrated efficacy in reducing disease activity in relapsing‐remitting multiple sclerosis (MS). We evaluated rituximab in adults with primary progressive MS (PPMS) through 96 weeks and safety through 122 weeks.


Multiple Sclerosis Journal | 2008

Differential diagnosis of suspected multiple sclerosis: a consensus approach

Dh Miller; Brian G. Weinshenker; Massimo Filippi; Brenda Banwell; Jeffrey Cohen; Mark S. Freedman; Steven L. Galetta; Michael Hutchinson; R. T. Johnson; Ludwig Kappos; Jun-ichi Kira; Fred D. Lublin; Henry F. McFarland; Xavier Montalban; Hillel Panitch; J. R. Richert; Stephen C. Reingold; C.H. Polman

Background and objectives Diagnosis of multiple sclerosis (MS) requires exclusion of diseases that could better explain the clinical and paraclinical findings. A systematic process for exclusion of alternative diagnoses has not been defined. An International Panel of MS experts developed consensus perspectives on MS differential diagnosis. Methods Using available literature and consensus, we developed guidelines for MS differential diagnosis, focusing on exclusion of potential MS mimics, diagnosis of common initial isolated clinical syndromes, and differentiating between MS and non-MS idiopathic inflammatory demyelinating diseases. Results We present recommendations for 1) clinical and paraclinical red flags suggesting alternative diagnoses to MS; 2) more precise definition of “clinically isolated syndromes” (CIS), often the first presentations of MS or its alternatives; 3) algorithms for diagnosis of three common CISs related to MS in the optic nerves, brainstem, and spinal cord; and 4) a classification scheme and diagnosis criteria for idiopathic inflammatory demyelinating disorders of the central nervous system. Conclusions Differential diagnosis leading to MS or alternatives is complex and a strong evidence base is lacking. Consensus-determined guidelines provide a practical path for diagnosis and will be useful for the non-MS specialist neurologist. Recommendations are made for future research to validate and support these guidelines. Guidance on the differential diagnosis process when MS is under consideration will enhance diagnostic accuracy and precision.


Journal of Immunology | 2007

Distinct Effector Cytokine Profiles of Memory and Naive Human B Cell Subsets and Implication in Multiple Sclerosis

Martin Duddy; Masaaki Niino; Femina Adatia; Sherry Hebert; Mark S. Freedman; Harry Atkins; Ho Jin Kim; Amit Bar-Or

Although recent animal studies have fuelled growing interest in Ab-independent functions of B cells, relatively little is known about how human B cells and their subsets may contribute to the regulation of immune responses in either health or disease. In this study, we first confirm that effector cytokine production by normal human B cells is context dependent and demonstrate that this involves the reciprocal regulation of proinflammatory and anti-inflammatory cytokines. We further report that this cytokine network is dysregulated in patients with the autoimmune disease multiple sclerosis, whose B cells exhibit a decreased average production of the down-regulatory cytokine IL-10. Treatment with the approved chemotherapeutic agent mitoxantrone reciprocally modulated B cell proinflammatory and anti-inflammatory cytokines, establishing that the B cell cytokine network can be targeted in vivo. Prospective studies of human B cells reconstituting following in vivo depletion suggested that different B cell subsets produced distinct effector cytokines. We confirmed in normal human B cell subsets that IL-10 is produced almost exclusively by naive B cells while the proinflammatory cytokines lymphotoxin and TNF-α are largely produced by memory B cells. These results point to an in vivo switch in the cytokine “program” of human B cells transitioning from the naive pool to the memory pool. We propose a model that ascribes distinct and proactive roles to memory and naive human B cell subsets in the regulation of memory immune responses and in autoimmunity. Our findings are of particular relevance at a time when B cell directed therapies are being applied to clinical trials of several autoimmune diseases.


Annals of Neurology | 2007

Glatiramer acetate in primary progressive multiple sclerosis: Results of a multinational, multicenter, double-blind, placebo-controlled trial

Jerry S. Wolinsky; Ponnada A. Narayana; Paul O'Connor; Patricia K. Coyle; Corey C. Ford; Kenneth Johnson; Aaron E. Miller; Lillian Pardo; Shaul Kadosh; David Ladkani; Lorne F. Kastrukoff; Pierre Duquette; Mark S. Freedman; Marc Debouverie; Catherine Lubetski; Gilles Edan; Etienne Roullet; Christian Confavreux; Alan J. Thompson; Lance Blumhardt; Stanley Hawkins; Thomas F. Scott; Daniel Wynn; Joanna Cooper; Stephen Thurston; Stanton B. Elias; Clyde Markowitz; David Mattson; John H. Noseworthy; Elizabeth A. Shuster

To determine whether glatiramer acetate (GA) slows accumulation of disability in primary progressive multiple sclerosis.


Lancet Neurology | 2009

Long-term effect of early treatment with interferon beta-1b after a first clinical event suggestive of multiple sclerosis: 5-year active treatment extension of the phase 3 BENEFIT trial

Ludwig Kappos; Mark S. Freedman; Chris H. Polman; Gilles Edan; Hans-Peter Hartung; David H. Miller; Xavier Montalban; Frederik Barkhof; Ernst-Wilhelm Radü; Carola Metzig; Lars Bauer; Vivian Lanius; Rupert Sandbrink; Christoph Pohl

BACKGROUND The Betaferon/Betaseron in newly emerging multiple sclerosis for initial treatment (BENEFIT) trial investigated the effect of treatment with interferon beta-1b after a clinically isolated syndrome. The 5-year active treatment extension compares the effects of early and delayed treatment with interferon beta-1b on time to clinically definite multiple sclerosis (CDMS) and other disease outcomes, including disability progression. METHODS Patients with a first event suggestive of multiple sclerosis and a minimum of two clinically silent lesions in MRI were randomly assigned to receive interferon beta-1b 250 microg (n=292; early treatment) or placebo (n=176; delayed treatment) subcutaneously every other day for 2 years, or until diagnosis of CDMS. All patients were then eligible to enter a prospectively planned follow-up phase with open-label interferon beta-1b up to a maximum of 5 years after randomisation. Patients and study personnel remained unaware of initial treatment allocation throughout the study. Primary endpoints were time to CDMS, time to confirmed disability progression measured with the expanded disability status scale, and the functional assessment of multiple sclerosis trial outcomes index (FAMS-TOI) at 5 years. Analysis of the primary endpoints was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00185211. FINDINGS 235 (80%) patients from the early treatment and 123 (70%) from the delayed treatment group completed the 5-year study. Early treatment reduced the risk of CDMS by 37% (hazard ratio [HR] 0.63, 95% CI 0.48-0.83; p=0.003) compared with delayed treatment. The risk for confirmed disability progression was not significantly lower in the early treatment group (0.76, 0.52-1.11; p=0.177). At 5 years, median FAMS-TOI scores were 125 in both groups. No significant differences in other disability related outcomes were recorded. Frequency and severity of adverse events remained within the established safety and tolerability profile of interferon beta-1b. INTERPRETATION Effects on the rate of conversion to CDMS and the favourable long-term safety and tolerability profile support early initiation of treatment with interferon beta-1b, although a delay in treatment by up to 2 years did not affect long-term disability outcomes. FUNDING Bayer Schering Pharma.


Lancet Neurology | 2007

Clinical features and viral serologies in children with multiple sclerosis: a multinational observational study

Brenda Banwell; Lauren B. Krupp; Julia Kennedy; Raymond Tellier; Silvia Tenembaum; Jayne Ness; Anita Belman; Alexei Boiko; Olga Bykova; Emmanuelle Waubant; Jean K. Mah; Cristina A. Stoian; Marcelo Kremenchutzky; Maria Rita Bardini; Martino Ruggieri; Mary Rensel; Jin S. Hahn; Bianca Weinstock-Guttman; E. Ann Yeh; Kevin Farrell; Mark S. Freedman; Matti Iivanainen; Meri Sevon; Virender Bhan; Marie-Emmanuelle Dilenge; Derek Stephens; Amit Bar-Or

BACKGROUND The full spectrum of clinical manifestations and outcome, and the potential importance of regional or demographic features or viral triggers in paediatric multiple sclerosis (MS), has yet to be fully characterised. Our aim was to determine some of these characteristics in children with MS. METHODS 137 children with MS and 96 control participants matched by age and geographical region were recruited in a multinational study. They underwent structured clinical-demographic interviews, review of academic performance, physical examination, disability assessment (MS patients only), and standardised assays for IgG antibodies directed against Epstein-Barr virus, cytomegalovirus, parvovirus B19, varicella zoster virus, and herpes simplex virus. FINDINGS MS was relapsing-remitting at diagnosis in 136 (99%) children. The first MS attack resembled acute disseminated encephalomyelitis (ADEM) in 22 (16%) of the children, most under 10 years old (mean age 7.4 [SD 4.2] years). Children with ADEM-like presentations were significantly younger than were children with polyfocal (11.2 [4.5] years; p<0.0001) or monofocal (12.0 [3.8] years; p=0.0005) presentations. Permanent physical disability (EDSS>or=4.0) developed within 5 years in 15 (13%) of the 120 children for whom EDSS score was available. 23 (17%) had impaired academic performance, which was associated with increasing disease duration (p=0.02). Over 108 (86%) of the children with MS, irrespective of geographical residence, were seropositive for remote EBV infection, compared with only 61 (64%) of matched controls (p=0.025, adjusted for multiple comparisons). Children with MS did not differ from controls in seroprevalence of the other childhood viruses studied, nor with respect to month of birth, sibling number, sibling rank, or exposure to young siblings. INTERPRETATION Paediatric MS is a relapsing-remitting disease, with presenting features that vary by age at onset. MS in children might be associated with exposure to EBV, suggesting a possible role for EBV in MS pathobiology.


Nature Medicine | 2007

Self-antigen tetramers discriminate between myelin autoantibodies to native or denatured protein

Kevin C. O'Connor; Katherine McLaughlin; Philip L. De Jager; Tanuja Chitnis; Estelle Bettelli; Chenqi Xu; William H. Robinson; Sunil V Cherry; Amit Bar-Or; Brenda Banwell; Hikoaki Fukaura; Toshiyuki Fukazawa; Silvia Tenembaum; Susan J. Wong; Norma P. Tavakoli; Zhannat Idrissova; Vissia Viglietta; Kevin Rostasy; Daniela Pohl; Russell C. Dale; Mark S. Freedman; Lawrence Steinman; Guy J. Buckle; Vijay K. Kuchroo; David A. Hafler; Kai W. Wucherpfennig

The role of autoantibodies in the pathogenesis of multiple sclerosis (MS) and other demyelinating diseases is controversial, in part because widely used western blotting and ELISA methods either do not permit the detection of conformation-sensitive antibodies or do not distinguish them from conformation-independent antibodies. We developed a sensitive assay based on self-assembling radiolabeled tetramers that allows discrimination of antibodies against folded or denatured myelin oligodendrocyte glycoprotein (MOG) by selective unfolding of the antigen domain. The tetramer radioimmunoassay (RIA) was more sensitive for MOG autoantibody detection than other methodologies, including monomer-based RIA, ELISA or fluorescent-activated cell sorting (FACS). Autoantibodies from individuals with acute disseminated encephalomyelitis (ADEM) selectively bound the folded MOG tetramer, whereas sera from mice with experimental autoimmune encephalomyelitis induced with MOG peptide immunoprecipitated only the unfolded tetramer. MOG-specific autoantibodies were identified in a subset of ADEM but only rarely in adult-onset MS cases, indicating that MOG is a more prominent target antigen in ADEM than MS.


Lancet Neurology | 2012

Comparison of two dosing frequencies of subcutaneous interferon beta-1a in patients with a first clinical demyelinating event suggestive of multiple sclerosis (REFLEX): a phase 3 randomised controlled trial

Giancarlo Comi; Nicola De Stefano; Mark S. Freedman; Frederik Barkhof; Chris H. Polman; Bernard M. J. Uitdehaag; Florence Casset-Semanaz; Brian Hennessy; Margaretha Stam Moraga; Sanda Rocak; Bettina Stubinski; Ludwig Kappos

BACKGROUND In patients presenting with a first clinical demyelinating event that is suggestive of multiple sclerosis (MS), treatment with interferon beta can delay the occurrence of further attacks and the onset of MS. We investigated the effects of two dosing frequencies of subcutaneous interferon beta-1a in patients with a first clinical demyelinating event. METHODS We undertook a multicentre phase 3 study (REbif FLEXible dosing in early MS [REFLEX]) that included patients (aged 18-50 years) with a single clinical event suggestive of MS, and at least two clinically silent T2 lesions on brain MRI. Participants were randomly assigned in a 1:1:1 ratio by use of a centralised interactive voice response system to receive the serum-free formulation of subcutaneous interferon beta-1a 44 μg three times a week or once a week (plus placebo twice a week for masking), or placebo three times a week for up to 24 months. Patients and physicians were masked to group allocation. The primary endpoint was time to a diagnosis of MS as defined by the 2005 McDonald criteria and the main secondary endpoint was time to clinically definite MS (CDMS) as defined by the Poser criteria. Analysis was by intention to treat. The study is registered with ClinicalTrials.gov, number NCT00404352. FINDINGS 517 patients were randomly assigned (171 to subcutaneous interferon beta-1a three times a week, 175 to subcutaneous interferon beta-1a once a week, and 171 to placebo) and 515 were treated. The 2-year cumulative probability of McDonald MS was significantly lower in patients treated with subcutaneous interferon beta-1a (three times a week 62·5%, p<0·0001, hazard ratio [HR] 0·49 [95% CI 0·38-0·64]; once a week 75·5%, p=0·008, HR 0·69 [0·54-0·87]) versus placebo (85·8%). 2-year rates of conversion to CDMS were lower for both interferon beta-1a dosing regimens (three times a week 20·6%, p=0·0004, HR 0·48 [0·31-0·73]; once a week 21·6%, p=0·0023, HR 0·53 [0·35-0·79]) than for placebo (37·5%). Adverse events were within the established profile for subcutaneous interferon beta-1a. INTERPRETATION Both regimens of subcutaneous interferon beta-1a delayed clinical relapses and subclinical disease activity. The potential differences between the regimens warrant longer-term study. FUNDING Merck Serono SA, Geneva, Switzerland.


Annals of Neurology | 2010

Chronic Cerebrospinal Venous Insufficiency and Multiple Sclerosis

Omar Khan; Massimo Filippi; Mark S. Freedman; Frederik Barkhof; Paula Dore-Duffy; Hans Lassmann; Bruce D. Trapp; Amit Bar-Or; Imad Zak; Marilyn J. Siegel; Robert P. Lisak

A chronic state of impaired venous drainage from the central nervous system, termed chronic cerebrospinal venous insufficiency (CCSVI), is claimed to be a pathologic phenomenon exclusively seen in multiple sclerosis (MS). This has invigorated the causal debate of MS and generated immense interest in the patient and scientific communities. A potential shift in the treatment paradigm of MS involving endovascular balloon angioplasty or venous stent placement has been proposed as well as conducted in small patient series. In some cases, it may have resulted in serious injury. In this Point of View, we discuss the recent investigations that led to the description of CCSVI as well as the conceptual and technical shortcomings that challenge the potential relationship of this phenomenon to MS. The need for conducting carefully designed and rigorously controlled studies to investigate CCVSI has been recognized by the scientific bodies engaged in MS research. Several scientific endeavors examining the presence of CCSVI in MS are being undertaken. At present, invasive and potentially dangerous endovascular procedures as therapy for patients with MS should be discouraged until such studies have been completed, analyzed, and debated in the scientific arena. ANN NEUROL 2010;67:286–290


Annals of Neurology | 2008

Magnetization transfer ratio evolution with demyelination and remyelination in multiple sclerosis lesions.

Jacqueline T. Chen; D. Louis Collins; Harold Atkins; Mark S. Freedman; Douglas L. Arnold

To assess demyelination and remyelination in vivo in acute gadolinium (Gd)‐enhancing lesions of multiple sclerosis (MS).

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Harold Atkins

Ottawa Hospital Research Institute

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Xavier Montalban

Autonomous University of Barcelona

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Frederik Barkhof

VU University Medical Center

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Amit Bar-Or

Montreal Neurological Institute and Hospital

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Jerry S. Wolinsky

University of Texas Health Science Center at Houston

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Giancarlo Comi

Vita-Salute San Raffaele University

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Aaron E. Miller

Icahn School of Medicine at Mount Sinai

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