Papers by Jeffrey Bennett
Journal of neuro-ophthalmology : the official journal of the North American Neuro-Ophthalmology Society, Jan 12, 2017
Journal of Neuroimmunology, Jul 1, 2011
Neuromyelitis optica (NMO) is an inflammatory demyelinating disease that predominantly affects th... more Neuromyelitis optica (NMO) is an inflammatory demyelinating disease that predominantly affects the optic nerves and spinal cord. Recombinant antibodies (rAbs) generated from clonally expanded plasma cells in an NMO patient are specific to AQP4 and pathogenic. We screened phage-displayed peptide libraries with these rAbs, and identified 14 high affinity linear and conformational peptides. The linear peptides shared sequence homologies with NMO autoantigen AQP4 on the extracellular surface. Competitive inhibition ELISA and immunocytochemistry demonstrated that these peptides represent epitopes of NMO autoantigen AQP4. Peptide epitopes/ mimotopes may have potential uses for disease prognosis, monitoring, and therapy.

Acta Neuropathologica Communications, 2020
Most cases of neuromyelitis optica spectrum disorders (NMOSD) harbor pathogenic autoantibodies ag... more Most cases of neuromyelitis optica spectrum disorders (NMOSD) harbor pathogenic autoantibodies against the water channel aquaporin 4 (AQP4). Binding of these antibodies to AQP4 on astrocytes initiates damage to these cells, which culminates in the formation of large tissue destructive lesions in the central nervous system (CNS). Consequently, untreated patients may become permanently blind or paralyzed. Studies on the induction and breakage of tolerance to AQP4 could be of great benefit for NMOSD patients. So far, however, all attempts to create suitable animal models by active sensitization have failed. We addressed this challenge and identified peptides, which mimic the conformational AQP4 epitopes recognized by pathogenic antibodies of NMOSD patients. Here we show that these mimotopes can induce the production of AQP4-reactive antibodies in Lewis rats. Hence, our results provide a conceptual framework for the formation of such antibodies in NMOSD patients, and aid to improve immu...

Multiple Sclerosis and Related Disorders, 2020
To assess the effect of anti-CD20 B-cell depletion with rituximab (RTX) on relapse rates in myeli... more To assess the effect of anti-CD20 B-cell depletion with rituximab (RTX) on relapse rates in myelin oligodendrocyte glycoprotein antibody-associated disorder (MOGAD). Methods: Retrospective review of RTX-treated MOGAD patients from 29 centres in 13 countries. The primary outcome measure was change in relapse rate after starting rituximab (Poisson regression model). Results: Data on 121 patients were analysed, including 30 (24.8%) children. Twenty/121 (16.5%) were treated after one attack, of whom 14/20 (70.0%) remained relapse-free after median (IQR) 11.2 (6.3-14.1) months. The remainder (101/121, 83.5%) were treated after two or more attacks, of whom 53/101 (52.5%) remained relapse-free after median 12.1 (6.3-24.9) months. In this 'relapsing group', relapse rate declined by 37% (95%CI=19-52%, p<0.001) overall, 63% (95%CI=35-79%, p = 0.001) when RTX was used first line (n = 47), and 26% (95%CI=2-44%, p = 0.038) when used after other steroid-sparing immunotherapies (n = 54). Predicted 1-year and 2-year relapse-free survival was 79% and 55% for first-line RTX therapy, and 38% and 18% for second-/third-line therapy. Circulating CD19 + B-cells were suppressed to <1% of total circulating lymphocyte population at the time of 45/57 (78.9%) relapses. Conclusion: RTX reduced relapse rates in MOGAD. However, many patients continued to relapse despite apparent B-cell depletion. Prospective controlled studies are needed to validate these results.
Journal of Neuro-Ophthalmology, 2018
The current management of acute optic neuritis (ON) is focused on expediting visual recovery thro... more The current management of acute optic neuritis (ON) is focused on expediting visual recovery through the use of high-dose intravenous corticosteroids. The recent identification of specific autoantibodies associated with central nervous system inflammatory disorders has provided novel insights into immune targets and mechanisms that impact the prognosis, treatment, and recurrence of ON. Therefore, neurologists and ophthalmologists need to be aware of clinical, laboratory, and imaging findings that may provide important clues to the etiology of ON and the potential need for aggressive management. Moving forward, rapid and accurate diagnosis of inflammatory ON will likely be critical for implementing clinical care that optimizes short-term and long-term therapeutic outcomes.

Science China. Life sciences, Jan 26, 2016
We characterized a unique group of patients with neuromyelitis optica spectrum disorder (NMOSD) w... more We characterized a unique group of patients with neuromyelitis optica spectrum disorder (NMOSD) who carried autoantibodies of aquaporin-4 (AQP4) and myelin-oligodendrocyte glycoprotein (MOG). Among the 125 NMOSD patients, 10 (8.0%) were AQP4- and MOG-ab double positive, and 14 (11.2%) were MOG-ab single positive. The double-positive patients had a multiphase disease course with a high annual relapse rate (P=0.0431), and severe residual disability (P>0.0001). Of the double- positive patients, 70% had MS-like brain lesions, more severe edematous, multifocal regions on spinal magnetic resonance imaging (MRI), pronounced decreases of retinal nerve fiber layer thickness and atrophy of optic nerves. In contrast, patients with only MOG-ab had a higher ratio of monophasic disease course and mild residual disability. Spinal cord MRI illustrated multifocal cord lesions with mild edema, and brain MRIs showed more lesions around lateral ventricles. NMOSD patients carrying both autoantibodies...

Acta neuropathologica communications, Jan 31, 2014
Antibodies against myelin oligodendrocyte glycoprotein (MOG-IgG) are present in some neuromyeliti... more Antibodies against myelin oligodendrocyte glycoprotein (MOG-IgG) are present in some neuromyelitis optica patients who lack antibodies against aquaporin-4 (AQP4-IgG). The effects of neuromyelitis optica MOG-IgG in the central nervous system have not been investigated in vivo. We microinjected MOG-IgG, obtained from patients with neuromyelitis optica, into mouse brains and compared the results with AQP4-IgG. MOG-IgG caused myelin changes and altered the expression of axonal proteins that are essential for action potential firing, but did not produce inflammation, axonal loss, neuronal or astrocyte death. These changes were independent of complement and recovered within two weeks. By contrast, AQP4-IgG produced complement-mediated myelin loss, neuronal and astrocyte death with limited recovery at two weeks. These differences mirror the better outcomes for MOG-IgG compared with AQP4-IgG patients and raise the possibility that MOG-IgG contributes to pathology in some neuromyelitis optic...

Annals of Neurology, 2012
Objective-Neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the central nerv... more Objective-Neuromyelitis optica (NMO) is an inflammatory demyelinating disease of the central nervous system. Circulating autoantibodies (NMO-IgG) against astrocyte water channel aquaporin-4 (AQP4) cause complement-and cell-mediated astrocyte damage with consequent neuroinflammation and demyelination. Current NMO therapies, which have limited efficacy, include immunosuppression and plasma exchange. The objective of this study was to develop a potential new NMO therapy based on blocking of pathogenic NMO-IgG to its target, AQP4. Methods-We generated non-pathogenic recombinant monoclonal anti-AQP4 antibodies that selectively block NMO-IgG binding to AQP4. These antibodies comprise a tight-binding anti-AQP4 Fab and a mutated Fc that lacks functionality for complement-and cell-mediated cytotoxicity. The efficacy of the blocking antibodies was studied using cell culture, spinal cord slice and in vivo mouse models of NMO. Results-In AQP4-expressing cell cultures, the non-pathogenic competing antibodies blocked binding of NMO-IgG in human sera, reducing to near zero complement-and cell-mediated cytotoxicity. The antibodies prevented the development of NMO lesions in an ex vivo spinal cord slice model of NMO and in an in vivo mouse model, without causing cytotoxicity. Interpretation-Our results provide proof-of-concept for therapy of NMO with blocking antibodies. The broad efficacy of antibody inhibition is likely due to steric competition because of its large physical size compared to AQP4. Blocker therapy to prevent binding of pathogenic autoantibodies to their targets may be useful for treatment of other autoimmune diseases as well.

Journal of neuroinflammation, Jan 25, 2017
Antibodies to the myelin oligodendrocyte glycoprotein (MOG) are associated with a subset of infla... more Antibodies to the myelin oligodendrocyte glycoprotein (MOG) are associated with a subset of inflammatory demyelinating diseases of the central nervous system such as acute disseminated encephalomyelitis and neuromyelitis optica spectrum disorders. However, whether human MOG antibodies are pathogenic or an epiphenomenon is still not completely clear. Although MOG is highly conserved within mammals, previous findings showed that not all human MOG antibodies bind to rodent MOG. We therefore hypothesized that human MOG antibody-mediated pathology in animal models may only be evident using species-specific MOG antibodies. We screened 80 human MOG antibody-positive samples for their reactivity to mouse and rat MOG using either a live cell-based assay or immunohistochemistry on murine, rat, and human brain tissue. Selected samples reactive to either human MOG or rodent MOG were subsequently tested for their ability to induce complement-mediated damage in murine organotypic brain slices or ...

Background: B cells are postulated to play multiple roles in the pathogenesis of multiple scleros... more Background: B cells are postulated to play multiple roles in the pathogenesis of multiple sclerosis (MS) including pathogenic antibody production, antigen-presentation and pro-inflammatory cytokine secretion. Natalizumab and fingolimod are effective MS therapies that disrupt lymphocyte migration but exert differential effects on B cell maturation and trafficking. Herein, we investigated their effects on peripheral blood and cerebrospinal fluid (CSF) B cell repertoires.Methods: Paired CSF and peripheral blood (PB) lymphocytes were collected from MS patients at baseline and after 6 months of treatment with fingolimod (n = 4) or natalizumab (n = 4). B cell subsets including naïve, CD27+ memory, CD27-IgD- double-negative B cells and plasmablasts were collected by FACS and their respective heavy-chain variable region (VH) repertoires assessed by next generation deep sequencing (Illumina MiSeq).Results: Treatment with fingolimod lead to a distinct contraction of the PB B cell pool whereas...

Optic Neuritis
CONTINUUM: Lifelong Learning in Neurology, 2019
PURPOSE OF REVIEW This article discusses the clinical presentation, evaluation, and management of... more PURPOSE OF REVIEW This article discusses the clinical presentation, evaluation, and management of the patient with optic neuritis. Initial emphasis is placed on clinical history, examination, diagnostic testing, and medical decision making, while subsequent focus is placed on examining specific inflammatory optic neuropathies. Clinical clues, examination findings, neuroimaging, and laboratory testing that differentiate autoimmune, granulomatous, demyelinating, infectious, and paraneoplastic causes of optic neuritis are assessed, and current treatments are evaluated. RECENT FINDINGS Advances in technology and immunology have enhanced our understanding of the pathologies driving inflammatory optic nerve injury. Clinicians are now able to interrogate optic nerve structure and function during inflammatory injury, rapidly identify disease-relevant autoimmune targets, and deliver timely therapeutics to improve visual outcomes. SUMMARY Optic neuritis is a common clinical manifestation of c...

Glia, 2018
Multiple sclerosis (MS) and neuromyelitis optica (NMO) are inflammatory demyelinating disorders o... more Multiple sclerosis (MS) and neuromyelitis optica (NMO) are inflammatory demyelinating disorders of the central nervous system (CNS) with evidence of antibody-mediated pathology. Using ex vivo organotypic mouse cerebellar slice cultures, we have demonstrated that recombinant antibodies (rAbs) cloned from cerebrospinal fluid plasmablasts of MS and NMO patients target myelin-and astrocyte-specific antigens to induce disease-specific oligodendrocyte loss and myelin degradation. In this study, we examined glial cell responses and myelin integrity during recovery from disease-specific antibody-mediated injury. Following exposure to MS rAb and human complement (HC) in cerebellar explants, myelinating oligodendrocytes repopulated the demyelinated tissue and formed new myelin sheaths along axons. Remyelination was accompanied by pronounced microglial activation. In contrast, following treatment with NMO rAb and HC, there was rapid regeneration of astrocytes and pre-myelinating oligodendrocytes but little formation of myelin sheaths on preserved axons. Deficient remyelination was associated with progressive axonal loss and the return of microglia to a resting state. Our results indicate that antibody-mediated demyelination in MS and NMO show distinct capacities for recovery associated with differential injury to adjacent axons and variable activation of microglia. Remyelination was rapid in MS rAb plus HC-induced demyelination. By contrast, oligodendrocyte maturation and remyelination failed following NMO rAb-mediated injury despite the rapid restoration of astrocytes and preservation of axons in early lesions.
Acta neuropathologica communications, Jan 24, 2017
Intrathecal immunoglobulin G (IgG) synthesis, cerebrospinal fluid (CSF) oligoclonal IgG bands and...
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Papers by Jeffrey Bennett