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Latov N, Brannagan TH, Sander HW, Gondim FDAA. Anti-MAG neuropathy: historical aspects, clinical-pathological correlations, and considerations for future therapeutical trials. ARQUIVOS DE NEURO-PSIQUIATRIA 2024; 82:1-7. [PMID: 38325389 PMCID: PMC10849826 DOI: 10.1055/s-0043-1777728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 11/21/2023] [Indexed: 02/09/2024]
Abstract
BACKGROUND Patients with anti-MAG neuropathy present with distal demyelinating polyneuropathy, IgM monoclonal gammopathy, and elevated titers of anti-MAG antibodies. OBJECTIVE This paper reviews what is known about the clinical presentation, course, pathophysiology, and treatment of anti-MAG neuropathy, with considerations for the design of therapeutic trials. METHODS A literature review of the medical and scientific literature related to anti-MAG neuropathy, and the design of therapeutic clinical trials in peripheral neuropathy. RESULTS Anti-MAG neuropathy can remain indolent for many years but then enter a progressive phase. Highly elevated antibody titers are diagnostic, but intermediate titers can also occur in chronic inflammatory demyelinating polyneuropathy (CIDP). The peripheral nerves can become inexcitable, thereby masking the demyelinating abnormalities. There is good evidence that the anti-MAG antibodies cause neuropathy. Reduction of the autoantibody concentration by agents that target B-cells was reported to result in clinical improvement in case series and uncontrolled trials, but not in controlled clinical trials, probably due to inadequate trial design. CONCLUSION We propose that therapeutic trials for anti-MAG neuropathy include patients with the typical presentation, some degree of weakness, highly elevated anti-MAG antibody titers, and at least one nerve exhibiting demyelinating range abnormalities. Treatment with one or a combination of anti-B-cell agents would aim at reducing the autoantibody concentration by at least 60%. A trial duration of 2 years may be required to show efficacy. The neuropathy impairment score of the lower extremities (NIS-LL) plus the Lower Limb Function (LLF) score would be a suitable primary outcome measure.
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Affiliation(s)
- Norman Latov
- Weil Medical College of Cornell University, Peripheral Neuropathy Center, New York, New York, United States.
| | - Thomas H. Brannagan
- Columbia University, Vagelos College of Physicians and Surgeons, Peripheral Neuropathy Center, Department of Neurology, New York, New York, United States.
| | - Howard W. Sander
- New York University, Department of Neurology, New York, New York, United States.
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Mariotto S, de Gaspari P, Jäger D, Hahn S, Forni C, Saschenbrecker S, Lattwein E, Dinoto A, Ferrari S. A novel cell-based immunofluorescence assay for the detection of autoantibodies to myelin-associated glycoprotein. Front Neurol 2023; 14:1289810. [PMID: 38169815 PMCID: PMC10758835 DOI: 10.3389/fneur.2023.1289810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 12/01/2023] [Indexed: 01/05/2024] Open
Abstract
Peripheral neuropathy with antibodies to myelin-associated glycoprotein (MAG) is an autoimmune demyelinating disorder of the peripheral nervous system caused by pathogenic IgM recognizing the human natural killer-1 glycoepitope expressed on MAG. This study aimed to analyze the performance of a new indirect immunofluorescence cell-based assay (CBA, EUROIMMUN) for the detection of anti-MAG IgM. Antibody reactivity was determined in sera from 95 patients with clinical and neurophysiological evidence of anti-MAG-associated neuropathy and in control samples from 55 patients with other forms of peripheral neuropathy. Compared to the results of the gold standard method (ELISA, Bühlmann) and using samples at a dilution of 1:100, the CBA had a sensitivity of 98.9% and a specificity of 100% (PPV 100%, NPV 98.2%). In conclusion, the CBA allows the detection of antibodies to MAG using an easy and standardized technique, and it presents a sensitive and specific alternative to the more time-consuming ELISA. Larger studies are needed to address anti-MAG titer monitoring in parallel with clinical activity.
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Affiliation(s)
- Sara Mariotto
- Neurology Unit, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Piera de Gaspari
- Neuroimmunology Group, Pediatric Research Institute, Padua, Italy
| | - Dominik Jäger
- Institute for Experimental Immunology, affiliated to EUROIMMUN Medizinische Labordiagnostika AG, Lübeck, Germany
| | - Stefanie Hahn
- Institute for Experimental Immunology, affiliated to EUROIMMUN Medizinische Labordiagnostika AG, Lübeck, Germany
| | - Cindy Forni
- Institute for Experimental Immunology, affiliated to EUROIMMUN Medizinische Labordiagnostika AG, Lübeck, Germany
| | - Sandra Saschenbrecker
- Institute for Experimental Immunology, affiliated to EUROIMMUN Medizinische Labordiagnostika AG, Lübeck, Germany
| | - Erik Lattwein
- Institute for Experimental Immunology, affiliated to EUROIMMUN Medizinische Labordiagnostika AG, Lübeck, Germany
| | - Alessandro Dinoto
- Neurology Unit, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Sergio Ferrari
- Neurology Unit, Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
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3
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Stino AM, Elsheikh B, Allen JA. Anti-myelin-associated glycoprotein neuropathy: Where do we stand? Muscle Nerve 2023; 68:823-832. [PMID: 37602932 DOI: 10.1002/mus.27954] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 07/19/2023] [Accepted: 07/22/2023] [Indexed: 08/22/2023]
Abstract
Myelin-associated glycoprotein (MAG) is a transmembrane glycoprotein concentrated in periaxonal Schwann cell and oligodendroglial membranes of myelin sheaths that serves as an antigen for immunoglobulin M (IgM) monoclonal antibodies. Individuals who harbor anti-MAG antibodies classically develop a progressive autoimmune peripheral neuropathy characterized clinically by ataxia, distal sensory loss, and gait instability, and electrophysiologically by distally accentuated conduction velocity slowing. Although off-label immunotherapy is common, there are currently no proven effective disease-modifying therapeutics, and most patients experience slow accumulation of disability over years and decades. The typically slowly progressive nature of this neuropathy presents unique challenges when trying to find effective anti-MAG therapeutic agents. Drug development has also been hampered by the lack of validated outcome measures that can detect clinically meaningful changes in a reasonable amount of time as well as by the lack of disease activity biomarkers. In this invited review, we provide an update on the state of clinicometric outcome measures and disease activity biomarkers in anti-MAG neuropathy. We highlight the insensitivity of widely used existing clinicometric outcome measures such as the Inflammatory Neuropathy Cause and Treatment (INCAT) disability score as well as the INCAT sensory subscore in anti-MAG neuropathy, referencing the two previous negative randomized controlled clinical trials evaluating rituximab. We then discuss newly emerging candidate therapeutic agents, including tyrosine kinase inhibitors and enhanced B-cell-depleting agents, among others. We conclude with a practical approach to the evaluation and management of anti-MAG neuropathy patients.
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Affiliation(s)
- Amro Maher Stino
- Department of Neurology, Division of Neuromuscular Medicine, University of Michigan, Ann Arbor, Michigan, USA
| | - Bakri Elsheikh
- Department of Neurology, Division of Neuromuscular Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Jeffrey A Allen
- Department of Neurology, Division of Neuromuscular Medicine, University of Minnesota, Minneapolis, Minnesota, USA
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4
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Sato R, Shimizu F, Kuwahara M, Mizukami Y, Watanabe K, Maeda T, Sano Y, Takeshita Y, Koga M, Kusunoki S, Kanda T. Autocrine TNF-α Increases Penetration of Myelin-Associated Glycoprotein Antibodies Across the Blood-Nerve Barrier in Anti-MAG Neuropathy. NEUROLOGY(R) NEUROIMMUNOLOGY & NEUROINFLAMMATION 2023; 10:10/3/e200086. [PMID: 36810162 PMCID: PMC9944621 DOI: 10.1212/nxi.0000000000200086] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Accepted: 11/28/2022] [Indexed: 02/23/2023]
Abstract
BACKGROUND AND OBJECTIVES Deposition of myelin-associated glycoprotein (MAG) immunoglobulin M (IgM) antibodies in the sural nerve is a key feature in anti-MAG neuropathy. Whether the blood-nerve barrier (BNB) is disrupted in anti-MAG neuropathy remains elusive.We aimed to evaluate the effect of sera from anti-MAG neuropathy at the molecular level using our in vitro human BNB model and observe the change of BNB endothelial cells in the sural nerve of anti-MAG neuropathy. METHODS Diluted sera from patients with anti-MAG neuropathy (n = 16), monoclonal gammopathies of undetermined significance (MGUS) neuropathy (n = 7), amyotrophic lateral sclerosis (ALS, n = 10), and healthy controls (HCs, n = 10) incubated with human BNB endothelial cells to identify the key molecule of BNB activation using RNA-seq and a high-content imaging system, and exposed with a BNB coculture model to evaluate small molecule/IgG/IgM/anti-MAG antibody permeability. RESULTS RNA-seq and the high-content imaging system showed the significant upregulation of tumor necrosis factor (TNF-α) and nuclear factor-kappa B (NF-κB) in BNB endothelial cells after exposure to sera from patients with anti-MAG neuropathy, whereas the serum TNF-α concentration was not changed among the MAG/MGUS/ALS/HC groups. Sera from patients with anti-MAG neuropathy did not increase 10-kDa dextran or IgG permeability but enhanced IgM and anti-MAG antibody permeability. Sural nerve biopsy specimens from patients with anti-MAG neuropathy showed higher TNF-α expression levels in BNB endothelial cells and preservation of the structural integrity of the tight junctions and the presence of more vesicles in BNB endothelial cells. Neutralization of TNF-α reduces IgM/anti-MAG antibody permeability. DISCUSSION Sera from individuals with anti-MAG neuropathy increased transcellular IgM/anti-MAG antibody permeability via autocrine TNF-α secretion and NF-κB signaling in the BNB.
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Affiliation(s)
| | - Fumitaka Shimizu
- From the Department of Neurology and Clinical Neuroscience (R.S., F.S., Y.S., Y.T., Michiaki Koga, T.K.), Yamaguchi University Graduate School of Medicine, Ube; Department of Neurology (Motoi Kuwahara, S.K.), Kindai University Faculty of Medicine, Osaka; Center for Gene Research (Y.M., K.W.), Yamaguchi University, Ube, Japan; and Japan Community Health Care Organization (S.K.).
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5
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Ohara M, Sanjo N, Kanouchi T, Yokota T. Entrapment partly participates in the longitudinal progression of neuropathy with anti-MAG antibodies. Rev Neurol (Paris) 2023; 179:118-122. [PMID: 36371264 DOI: 10.1016/j.neurol.2022.07.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 07/13/2022] [Accepted: 07/17/2022] [Indexed: 11/11/2022]
Abstract
Neuropathy with anti-myelin-associated glycoprotein (MAG) antibodies commonly demonstrates distal-dominant prolongation of nerve conduction. However, recent electrophysiological studies have shown that distal motor demyelination is not always a distinct feature. We aimed to elucidate whether the longitudinal progression of nerve impairment occurs in a distal-dominant manner. Seven patients with neuropathy with anti-MAG antibodies were enrolled. Sequential nerve conduction studies revealed nerve conduction reduction only at the wrist segment in the median nerve of the patients, but not in the ulnar nerve. Median nerve entrapment at the wrist may play a role in longitudinal disease progression in neuropathy with anti-MAG antibodies.
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Affiliation(s)
- M Ohara
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, 113-8519 Tokyo, Japan.
| | - N Sanjo
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, 113-8519 Tokyo, Japan.
| | - T Kanouchi
- Clinical Laboratory, Medical Hospital of Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, 113-8519 Tokyo, Japan.
| | - T Yokota
- Department of Neurology and Neurological Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, 113-8519 Tokyo, Japan.
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Polyneuropathy Associated with IgM Monoclonal Gammopathy; Advances in Genetics and Treatment, Focusing on Anti-MAG Antibodies. HEMATO 2022. [DOI: 10.3390/hemato3040045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
With increasing age, the chances of developing either MGUS or polyneuropathy increase as well. In some cases, there is a causative relationship between the IgM M-protein and polyneuropathy. In approximately half of these cases, IgM targets the myelin-associated glycoprotein (MAG). This results in chronic polyneuropathy with slowly progressive, predominantly sensory neurological deficits and distally demyelinating features in nerve conduction studies. Despite the disease being chronic and developing slowly, it can cause considerable impairment. We reviewed English medical publications between 1980 and May 2022 on IgM gammopathy-associated polyneuropathy, with special attention to studies addressing the pathophysiology or treatment of anti-MAG polyneuropathy. Treatment options have been limited to a temporizing effect of intravenous immunoglobulins in some patients and a more sustained effect of rituximab but in only 30 to 55 percent of patients. An increase in our knowledge concerning genetic mutations, particularly the MYD88L265P mutation, led to the development of novel targeted treatment options such as BTK inhibitors. Similarly, due to the increasing knowledge of the pathophysiology of anti-MAG polyneuropathy, new treatment options are emerging. Since anti-MAG polyneuropathy is a rare disease with diverse symptomatology, large trials with good outcome measures are a challenge.
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Briani C, Visentin A. Therapeutic Monoclonal Antibody Therapies in Chronic Autoimmune Demyelinating Neuropathies. Neurotherapeutics 2022; 19:874-884. [PMID: 35349079 PMCID: PMC9294114 DOI: 10.1007/s13311-022-01222-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/12/2022] [Indexed: 02/07/2023] Open
Abstract
Autoimmune diseases of the peripheral nervous system have so far been treated mainly with exogenous high-dose intravenous immunoglobulins (IVIg), that act through several mechanisms, including neutralization of pathogenic autoantibodies, modulation of lymphocyte activity, interference with antigen presentation, and interaction with Fc receptors, cytokines, and the complement system. Other therapeutic strategies have recently been developed, in part to address the increasing shortage of IVIg, prime among which is the use of B cell depleting monoclonal antibodies, or small molecule inhibitors targeting the B-cell specific kinases. Rituximab, a chimeric monoclonal antibody against CD20 + B lymphocytes, is currently the most used, especially in anti-MAG antibody neuropathy and autoimmune neuropathies with antibodies to nodal/paranodal antigens that are unresponsive to IVIg. After several reports of its efficacy in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), rituximab is currently under investigation in three Phase 2 trials in CIDP. In addition, the possible role of complement activation in the pathogenesis of chronic autoimmune neuropathies has brought into consideration drugs that can block the complement cascade, such as eculizumab, a monoclonal antibody already assessed in acute polyradiculoneuropathies, and approved for myasthenia gravis. Preliminary data on eculizumab in multifocal motor neuropathy have been published, but randomized controlled studies are pending. Moreover, the neonatal Fc receptor, that recycles IgGs by preventing their lysosome degradation, is an important and attractive pharmacological target. Antibodies against FcRn, which reduce circulating IgG (both pathogenic and non-pathogenic) have been developed. The FcRn blocker efgartigimod, a humanized IgG1-derived Fc fragment, which competitively inhibits the FcRn, has recently been approved for the treatment of myasthenia gravis and is currently under investigation in CIDP. In addition, the anti-human FcRn monoclonal antibody rozanolixizumab is currently being assessed in phase 2 trials in CIDP. However, none of the abovementioned monoclonal antibodies is currently approved for treatment of any immune-mediated neuropathies. While more specific and individualized therapies are being developed, the possibility of combined treatments targeting different pathogenic mechanisms deserves consideration as well.
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Affiliation(s)
- Chiara Briani
- Department of Neurosciences, Neurology Unit, University of Padova, Padova, Italy.
| | - Andrea Visentin
- Department of Medicine, Hematology Unit, University of Padova, Padova, Italy
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Stathopoulos P, Dalakas MC. Evolution of Anti-B Cell Therapeutics in Autoimmune Neurological Diseases. Neurotherapeutics 2022; 19:691-710. [PMID: 35182380 PMCID: PMC9294112 DOI: 10.1007/s13311-022-01196-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/31/2022] [Indexed: 02/08/2023] Open
Abstract
B cells have an ever-increasing role in the etiopathology of a number of autoimmune neurological disorders, acting as antigen-presenting cells facilitating antibody production but also as sensors, coordinators, and regulators of the immune response. In particular, B cells can regulate the T cell activation process through their participation in antigen presentation, production of proinflammatory cytokines (bystander activation or suppression), and contribution to ectopic lymphoid aggregates. Such an important interplay between B and T cells makes therapeutic depletion of B cells an attractive treatment strategy. The last decade, anti-B cell therapies using monoclonal antibodies against B cell surface molecules have evolved into a rational approach for successfully treating autoimmune neurological disorders, even when T cells seem to be the main effector cells. The paper summarizes basic aspects of B cell biology, discusses the roles of B cells in neurological autoimmunities, and highlights how the currently available or under development anti-B cell therapeutics exert their action in the wide spectrum and immunologically diverse neurological disorders. The efficacy of the various anti-B cell therapies and practical issues on induction and maintenance therapy is specifically detailed for the treatment of patients with multiple sclerosis, neuromyelitis-spectrum disorders, autoimmune encephalitis and hyperexcitability CNS disorders, autoimmune neuropathies, myasthenia gravis, and inflammatory myopathies. The success of anti-B cell therapies in inducing long-term remission in IgG4 neuroautoimmunities is also highlighted pointing out potential biomarkers for follow-up infusions.
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Affiliation(s)
- Panos Stathopoulos
- 1st Department of Neurology, National and Kapodistrian University of Athens, Athens, Greece
| | - Marinos C Dalakas
- Thomas Jefferson University, Philadelphia, PA, USA.
- Neuroimmunology Unit, National and Kapodistrian University of Athens, Athens, Greece.
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9
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Anti-MAG neuropathy: From biology to clinical management. J Neuroimmunol 2021; 361:577725. [PMID: 34610502 DOI: 10.1016/j.jneuroim.2021.577725] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Accepted: 09/20/2021] [Indexed: 12/19/2022]
Abstract
The acquired chronic demyelinating neuropathies include a growing number of disease entities that have characteristic, often overlapping, clinical presentations, mediated by distinct immune mechanisms, and responding to different therapies. After the discovery in the early 1980s, that the myelin associated glycoprotein (MAG) is a target antigen in an autoimmune demyelinating neuropathy, assays to measure the presence of anti-MAG antibodies were used as the basis to diagnose the anti-MAG neuropathy. The route was open for describing the clinical characteristics of this new entity as a chronic distal large fiber sensorimotor neuropathy, for studying its pathogenesis and devising specific treatment strategies. The initial use of chemotherapeutic agents was replaced by the introduction in the late 1990s of rituximab, a monoclonal antibody against CD20+ B-cells. Since then, other anti-B cells agents have been introduced. Recently a novel antigen-specific immunotherapy neutralizing the anti-MAG antibodies with a carbohydrate-based ligand mimicking the natural HNK-1 glycoepitope has been described.
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Latov N. Immune mechanisms, the role of complement, and related therapies in autoimmune neuropathies. Expert Rev Clin Immunol 2021; 17:1269-1281. [PMID: 34751638 DOI: 10.1080/1744666x.2021.2002147] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Autoimmune neuropathies have diverse presentations and underlying immune mechanisms. Demonstration of efficacy of therapeutic agents that inhibit the complement cascade would confirm the role of complement activation. AREAS COVERED A review of the pathophysiology of the autoimmune neuropathies, to identify those that are likely to be complement mediated. EXPERT OPINION Complement mediated mechanisms are implicated in the acute and chronic neuropathies associated with IgG or IgM antibodies that target the Myelin Associated Glycoprotein (MAG) or gangliosides in the peripheral nerves. Antibody and complement mechanisms are also suspected in the Guillain-Barré syndrome and chronic inflammatory demyelinating neuropathy, given the therapeutic response to plasmapheresis or intravenous immunoglobulins, even in the absence of an identifiable target antigen. Complement is unlikely to play a role in paraneoplastic sensory neuropathy associated with antibodies to HU/ANNA-1 given its intracellular localization. In chronic demyelinating neuropathy with anti-nodal/paranodal CNTN1, NFS-155, and CASPR1 antibodies, myotonia with anti-VGKC LGI1 or CASPR2 antibodies, or autoimmune autonomic neuropathy with anti-gAChR antibodies, the response to complement inhibitory agents would depend on the extent to which the antibodies exert their effects through complement dependent or independent mechanisms. Complement is also likely to play a role in Sjogren's, vasculitic, and cryoglobulinemic neuropathies.
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Affiliation(s)
- Norman Latov
- Department of Neurology, Weill Cornell Medical College, New York, USA
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11
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Koike H, Katsuno M. Paraproteinemia and neuropathy. Neurol Sci 2021; 42:4489-4501. [PMID: 34529193 DOI: 10.1007/s10072-021-05583-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 08/28/2021] [Indexed: 12/16/2022]
Abstract
Paraproteinemia is associated with different peripheral neuropathies. The major causes of neuropathy correlated with paraproteinemia are the deposition of immunoglobulin in the myelin, represented by anti-myelin-associated glycoprotein (MAG) neuropathy; deposition of immunoglobulin or its fragment in the interstitium, represented by immunoglobulin light chain amyloidosis (AL amyloidosis); and paraneoplastic mechanisms that cannot be solely attributed to the deposition of immunoglobulin or its fragment, represented by polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin change (POEMS) syndrome. Patients with anti-MAG neuropathy and POEMS syndrome present with slowing of nerve conduction parameters. This characteristic fulfills the electrodiagnostic criteria for chronic inflammatory demyelinating polyneuropathy (CIDP) defined by the European Academy of Neurology and Peripheral Nerve Society (EAN/PNS). Although direct damage caused by the deposition of amyloid can induce axonal damage in AL amyloidosis, some patients with this condition have features fulfilling the EAN/PNS electrodiagnostic criteria for CIDP. Conventional immunotherapies for CIDP, such as steroids, intravenous immunoglobulin, and plasma exchange, offer no or only minimal-to-modest benefit. Although rituximab can reduce the level of circulating autoantibodies, it may only be effective in some patients with anti-MAG neuropathy. Drugs including melphalan, thalidomide, lenalidomide, and bortezomib for POEMS syndrome and those including melphalan, thalidomide, lenalidomide, pomalidomide, bortezomib, ixazomib, and daratumumab for AL amyloidosis are considered. Since there will be more therapeutic options in the future, thereby enabling appropriate treatments for individual neuropathies, there is an increasing need for early diagnosis.
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Affiliation(s)
- Haruki Koike
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan.
| | - Masahisa Katsuno
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, 466-8550, Japan
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Kawagashira Y, Koike H, Takahashi M, Ohyama K, Iijima M, Katsuno M, Niwa JI, Doyu M, Sobue G. Aberrant Expression of Nodal and Paranodal Molecules in Neuropathy Associated With IgM Monoclonal Gammopathy With Anti-Myelin-Associated Glycoprotein Antibodies. J Neuropathol Exp Neurol 2021; 79:1303-1312. [PMID: 32856086 DOI: 10.1093/jnen/nlaa085] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 07/02/2020] [Accepted: 07/09/2020] [Indexed: 11/13/2022] Open
Abstract
To clarify the pathogenesis of anti-myelin-associated glycoprotein (MAG) antibody neuropathy associated with IgM monoclonal gammopathy (anti-MAG neuropathy), sural nerve biopsy specimens from 15 patients were investigated. Sodium channels, potassium channels, contactin-associated protein 1 (Caspr1), contactin 1, and neurofascin were evaluated by immunofluorescence in teased-fiber preparations. Immunoreactivity to the pan-sodium channel in both anti-MAG neuropathy patients and in normal controls was concentrated at the node of Ranvier unless there was demyelination, which was defined as the widening of the node of Ranvier. However, this immunoreactivity became weak or disappeared as demyelination progressed. In contrast, KCNQ2 immunostaining was nearly absent even in the absence of demyelination. The lengths of Caspr1, contactin 1, and pan-neurofascin immunostaining sites at the paranode were significantly increased compared with those of normal controls despite the absence of demyelination. The length of paranodal neurofascin staining correlated with the anti-MAG antibody titer, nerve conduction indices, the frequency of de/remyelination in teased-fiber preparations, and the frequency of widely spaced myelin (p < 0.05, p < 0.05, p < 0.01, and <0.05, respectively). These findings suggest that nodal and paranodal molecular alterations occur in early stages preceding the morphological changes associated with demyelination in anti-MAG neuropathy.
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Affiliation(s)
| | - Haruki Koike
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya
| | - Mie Takahashi
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya
| | - Ken Ohyama
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya
| | - Masahiro Iijima
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya
| | - Masahisa Katsuno
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya
| | - Jun-Ichi Niwa
- Department of Neurology, Aichi Medical University, Nagakute
| | - Manabu Doyu
- Department of Neurology, Aichi Medical University, Nagakute
| | - Gen Sobue
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya.,Research Division of Dementia and Neurodegenerative Disease, Nagoya University Graduate School of Medicine, Nagoya, Aichi, Japan
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Mechanisms of Nerve Damage in Neuropathies Associated with Hematological Diseases: Lesson from Nerve Biopsies. Brain Sci 2021; 11:brainsci11020132. [PMID: 33498362 PMCID: PMC7909400 DOI: 10.3390/brainsci11020132] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 01/15/2021] [Accepted: 01/18/2021] [Indexed: 12/15/2022] Open
Abstract
Despite the introduction of non-invasive techniques in the study of peripheral neuropathies, sural nerve biopsy remains the gold standard for the diagnosis of several neuropathies, including vasculitic neuropathy and neurolymphomatosis. Besides its diagnostic role, sural nerve biopsy has helped to shed light on the pathogenic mechanisms of different neuropathies. In the present review, we discuss how pathological findings helped understand the mechanisms of polyneuropathies complicating hematological diseases.
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Koike H, Mouri N, Fukami Y, Iijima M, Matsuo K, Yagi N, Saito A, Nakamura H, Takahashi K, Nakae Y, Okada Y, Tanaka F, Sobue G, Katsuno M. Two distinct mechanisms of neuropathy in immunoglobulin light chain (AL) amyloidosis. J Neurol Sci 2021; 421:117305. [PMID: 33540321 DOI: 10.1016/j.jns.2020.117305] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2020] [Revised: 11/28/2020] [Accepted: 12/29/2020] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Although polyneuropathy in patients with immunoglobulin light chain (AL) amyloidosis has been considered to be attributable to axonal degeneration resulting from amyloid deposition, patients with nerve conduction parameters indicating demyelination that mimics chronic inflammatory demyelinating polyneuropathy (CIDP) have also been reported anecdotally. METHODS We evaluated the electrophysiological and pathological features of 8 consecutive patients with AL amyloidosis who were referred for sural nerve biopsy. RESULTS Although findings of axonal neuropathy predominantly in the lower limbs were the cardinal feature, all patients showed one or more abnormalities of nerve conduction velocities or distal motor latencies. In particular, 2 of these patients fulfilled the definite electrophysiological for CIDP defined by the European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS). On electron microscopic examination of sural nerve biopsy specimens, Schwann cells apposed to amyloid fibrils became atrophic in all patients, suggesting that amyloid deposits directly affect neighboring tissues. Additionally, detachment of the neurilemma from the outermost compacted myelin lamella was seen where amyloid fibrils were absent in 4 patients. Electrophysiological findings suggestive of demyelination were more conspicuous in these patients compared with the other patients. The detachment of the neurilemma from the outermost compacted myelin lamella was particularly conspicuous in patients who fulfilled the definite EFNS/PNS electrophysiological criteria for CIDP. CONCLUSION Abnormalities of myelinated fibers unrelated to amyloid deposition may frequently occur in AL amyloidosis. Disjunction between myelin and the neurilemma may induce nerve conduction abnormalities suggestive of demyelination.
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Affiliation(s)
- Haruki Koike
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
| | - Naohiro Mouri
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Yuki Fukami
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Masahiro Iijima
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Koji Matsuo
- Department of Neurology, Kariya Toyota General Hospital, Aichi, Japan
| | - Nobuyasu Yagi
- Department of Neurology, Shizuoka Red Cross Hospital, Shizuoka, Japan
| | - Asami Saito
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Haruko Nakamura
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Keita Takahashi
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Yoshiharu Nakae
- Department of Neurology, Saiseikai Yokohamashi Nanbu Hospital, Yokohama, Japan
| | - Yohei Okada
- Department of Neurology, Aichi Medical University School of Medicine, Aichi, Japan
| | - Fumiaki Tanaka
- Department of Neurology and Stroke Medicine, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Gen Sobue
- Research Division of Dementia and Neurodegenerative Disease, Nagoya University Graduate School of Medicine, Nagoya, Japan
| | - Masahisa Katsuno
- Department of Neurology, Nagoya University Graduate School of Medicine, Nagoya, Japan.
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15
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Mihajkoska E, Poceva Panovska A, Brezovska K, Pendovska M, Taravari A, Suturkova L. The role of antibodies to peripheral nerve antigens in pathogenesis and laboratory evaluation of immune-mediated neuropathies. MAKEDONSKO FARMACEVTSKI BILTEN 2021. [DOI: 10.33320/maced.pharm.bull.2021.67.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Detection of antiganglioside autoantibodies and their association with clinically defined subtypes implicate an autoimmune mechanism of peripheraland cranial nerve damage in peripheral neuropathies.
Increased titer of antibodies that react with human peripheral nerve antigens have been reported in patients with motor neuropathy including Guillain-Barré syndrome,chronic inflammatory demyelinating polyneuropathy, multifocal motor neuropathy and sensory motor neuropathy. This study represents review of the data related to increased titers of anti-glucoconjugate antibodies in different autoimmune neuropathies and their correlation with existence of structural homology between bacterial and glycoconjugated structures, as a basis for understanding the immune pathological response to glycoproteins and glycolipids present in the human peripheral nerve as target antigens in autoimmune neuropathies.
Evaluation of presence and increased level of autoantibodies against peripheral nerve antigens could be an important parameter in laboratory evaluation, diagnosis and prognosis of autoimmune neuropathies and contribute in more efficient therapeutic approaches in treatment of these pathological conditions.
Keywords: anti-glycoconjugate antibodies, anti-ganglioside antibodies, peripheral nerves, autoimmune neuropathies
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Affiliation(s)
- Evgenija Mihajkoska
- Faculty of Pharmacy, Ss. Cyril and Methodius University in Skopje, Mother Theresa 47, 1000 Skopje, Republic of North Macedonia
| | - Ana Poceva Panovska
- Faculty of Pharmacy, Ss. Cyril and Methodius University in Skopje, Mother Theresa 47, 1000 Skopje, Republic of North Macedonia
| | - Katerina Brezovska
- Faculty of Pharmacy, Ss. Cyril and Methodius University in Skopje, Mother Theresa 47, 1000 Skopje, Republic of North Macedonia
| | - Marija Pendovska
- University Clinic for Hematology, Ss. Cyril and Methodius University in Skopje, Mother Theresa 47, 1000 Skopje, Republic of North Macedonia
| | - Arben Taravari
- Universiy Clinic for Neurology, Faculty of Medicine, Ss. Cyril and Methodius University in Skopje, 50 Divizija 6, 1000 Skopje, Republic of North Macedonia
| | - Ljubica Suturkova
- Faculty of Pharmacy, Ss. Cyril and Methodius University in Skopje, Mother Theresa 47, 1000 Skopje, Republic of North Macedonia
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16
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Mariotto S, Carta S, Bozzetti S, Zivelonghi C, Alberti D, Zanzoni S, Filosto M, Fusina S, Monaco S, Castellani F, Mantovani A, Cavallaro T, Briani C, Ferrari S. Sural nerve biopsy: current role and comparison with serum neurofilament light chain levels. J Neurol 2020; 267:2881-2887. [PMID: 32462349 DOI: 10.1007/s00415-020-09949-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 05/22/2020] [Accepted: 05/23/2020] [Indexed: 12/18/2022]
Abstract
The diagnosis of peripheral neuropathies can be challenging with consequent difficulties in patients' management. The aim of this study was to explore the current diagnostic role of sural nerve biopsy and to compare pathological findings with serum neurofilament light chain levels (NfL) as biomarkers of axonal damage. We collected demographic, clinical, and paraclinical data of patients referred over 1 year to the Neurology Unit, University of Verona, Italy, to perform nerve biopsy for diagnostic purposes, and we analyzed NfL levels in available paired sera using a high sensitive technique (Quanterix, Simoa). Eighty-two patients were identified (37.8% females, median age 65.5 years). Neuropathy onset was frequently insidious (68.3%) with a slowly progressive course (76.8%). Lower limbs were usually involved (81.7%), with a predominance of sensory over motor symptoms (74.4% vs 42.7%). The most common neuropathological findings were a demyelinating pattern (76.8%), clusters of regenerations (58.5%), and unmyelinated fibers involvement on ultrastructural evaluation (52.4%). A definite pathological diagnosis was achieved in 29 cases, and in 20.7% of patients, the referral clinical diagnosis was modified. Coexistent hematological conditions and hepatitis were diagnostic confounding factors (p = 0.012 and 0.034, respectively). In the analyzed paired sera (n = 37), an inverse despite not significant relationship between NfL values and fiber density was observed (Spearman's rho - 0.312, p = 0.056). In addition, we noted increased serum NfL values of patients with active axonal degeneration. Nerve biopsy remains a useful diagnostic investigation to achieve a correct diagnosis and guide patients' management in selected cases of peripheral neuropathy. Serum NfL is an accessible and potential valuable marker of axonal damage in these conditions.
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Affiliation(s)
- Sara Mariotto
- Neurology Unit, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Policlinico GB Rossi, P.le LA Scuro 10, 37134, Verona, Italy.
| | - Sara Carta
- Neurology Unit, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Policlinico GB Rossi, P.le LA Scuro 10, 37134, Verona, Italy
| | - Silvia Bozzetti
- Neurology Unit, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Policlinico GB Rossi, P.le LA Scuro 10, 37134, Verona, Italy
| | - Cecilia Zivelonghi
- Neurology Unit, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Policlinico GB Rossi, P.le LA Scuro 10, 37134, Verona, Italy
| | - Daniela Alberti
- Neurology Unit, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Policlinico GB Rossi, P.le LA Scuro 10, 37134, Verona, Italy
| | - Serena Zanzoni
- Centro Piattaforme Tecnologiche, University of Verona, Verona, Italy
| | | | - Simone Fusina
- Neurology Unit, S. Bonifacio Hospital, Verona, Italy
| | - Salvatore Monaco
- Neurology Unit, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Policlinico GB Rossi, P.le LA Scuro 10, 37134, Verona, Italy
| | | | - Alessandro Mantovani
- Section of Endocrinology, Diabetes and Metabolism, University and Azienda Ospedaliera, Universitaria Integrata of Verona, Verona, Italy
| | - Tiziana Cavallaro
- Neurology Unit, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Policlinico GB Rossi, P.le LA Scuro 10, 37134, Verona, Italy
| | - Chiara Briani
- Department of Neurosciences, University of Padova, Padua, Italy
| | - Sergio Ferrari
- Neurology Unit, Department of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Policlinico GB Rossi, P.le LA Scuro 10, 37134, Verona, Italy
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17
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den Bergh PYK, Doorn PA, Jacobs BC, Querol L, Bunschoten C, Cornblath DR. Boundaries of chronic inflammatory demyelinating polyradiculoneuropathy. J Peripher Nerv Syst 2020; 25:4-8. [DOI: 10.1111/jns.12364] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Peter Y. K. den Bergh
- Neuromuscular Reference CentreUniversity Hospital St Luc, University of Louvain, Avenue Hippocrate 10 Brussels Belgium
| | - Pieter A. Doorn
- Department of Neurology, Erasmus MCUniversity Medical Center Rotterdam Wytemaweg 80 CN, Rotterdam The Netherlands
| | - Bart C. Jacobs
- Department of Neurology and Immunology, Erasmus MCUniversity Medical Center Rotterdam Wytemaweg 80 CN, Rotterdam The Netherlands
| | - Luis Querol
- Neuromuscular Diseases Unit, Department of Neurology, Hospital de la Santa Creu i Sant PauUniversitat Autònoma de Barcelona, Mas Casanovas 90 Barcelona Spain
| | - Carina Bunschoten
- Department of Neurology and Immunology, Erasmus MCUniversity Medical Center Rotterdam Wytemaweg 80 CN, Rotterdam The Netherlands
| | - David R. Cornblath
- Department of NeurologyJohns Hopkins University School of Medicine Meyer 6‐181a North, Wolfe Street, Baltimore US
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18
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Abstract
Sensory polyneuropathies, which are caused by dysfunction of peripheral sensory nerve fibers, are a heterogeneous group of disorders that range from the common diabetic neuropathy to the rare sensory neuronopathies. The presenting symptoms, acuity, time course, severity, and subsequent morbidity vary and depend on the type of fiber that is affected and the underlying cause. Damage to small thinly myelinated and unmyelinated nerve fibers results in neuropathic pain, whereas damage to large myelinated sensory afferents results in proprioceptive deficits and ataxia. The causes of these disorders are diverse and include metabolic, toxic, infectious, inflammatory, autoimmune, and genetic conditions. Idiopathic sensory polyneuropathies are common although they should be considered a diagnosis of exclusion. The diagnostic evaluation involves electrophysiologic testing including nerve conduction studies, histopathologic analysis of nerve tissue, serum studies, and sometimes autonomic testing and cerebrospinal fluid analysis. The treatment of these diseases depends on the underlying cause and may include immunotherapy, mitigation of risk factors, symptomatic treatment, and gene therapy, such as the recently developed RNA interference and antisense oligonucleotide therapies for transthyretin familial amyloid polyneuropathy. Many of these disorders have no directed treatment, in which case management remains symptomatic and supportive. More research is needed into the underlying pathophysiology of nerve damage in these polyneuropathies to guide advances in treatment.
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Affiliation(s)
- Kelly Graham Gwathmey
- Virginia Commonwealth University, Department of Neurology, 1101 E. Marshall Street, PO Box 980599, Richmond, VA 23298, USA
| | - Kathleen T Pearson
- Virginia Commonwealth University, Department of Neurology, 1101 E. Marshall Street, PO Box 980599, Richmond, VA 23298, USA
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19
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Garg N, Park SB, Howells J, Noto YI, Vucic S, Yiannikas C, Tomlinson SE, Huynh W, Simon NG, Mathey EK, Spies J, Pollard JD, Krishnan AV, Kiernan MC. Anti-MAG neuropathy: Role of IgM antibodies, the paranodal junction and juxtaparanodal potassium channels. Clin Neurophysiol 2018; 129:2162-2169. [PMID: 30144659 DOI: 10.1016/j.clinph.2018.07.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 06/12/2018] [Accepted: 07/15/2018] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To improve understanding of disease pathophysiology in anti-myelin-associated glycoprotein (anti-MAG) neuropathy to guide further treatment approaches. METHODS Anti-MAG neuropathy patients underwent clinical assessments, nerve conduction and excitability studies, and ultrasound assessment. RESULTS Patients demonstrated a distinctive axonal excitability profile characterised by a reduction in superexcitability [MAG: -14.2 ± 1.6% vs healthy controls (HC): -21.8 ± 1.2%; p < 0.01] without alterations in most other excitability parameters. Mathematical modelling of nerve excitability recordings suggested that changes in axonal function could be explained by a 72.5% increase in juxtaparanodal fast potassium channel activation and an accompanying hyperpolarization of resting membrane potential (by 0.3 mV) resulting in a 94.2% reduction in discrepancy between anti-MAG data and the healthy control model. Superexcitability changes correlated strongly with clinical and neurophysiological parameters. Furthermore, structural assessments demonstrated a proximal pattern of nerve enlargement (C6 nerve root cross-sectional area: 15.9 ± 8.1 mm2 vs HC: 9.1 ± 2.3 mm2; p < 0.05). CONCLUSIONS The imaging and neurophysiological results support the pathogenicity of anti-MAG IgM. Widening between adjacent loops of paranodal myelin due to antibodies would expand the pathway from the node to the juxtaparanode, increasing activation of juxtaparanodal fast potassium channels, thereby impairing saltatory conduction. SIGNIFICANCE Potassium channel blockers may prove beneficial in restoring conduction closer to its normal state and improving nerve function in anti-MAG neuropathy.
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Affiliation(s)
- Nidhi Garg
- Brain and Mind Centre, Sydney Medical School, The University of Sydney, 94 Mallett St, Camperdown, NSW 2050, Australia.
| | - Susanna B Park
- Brain and Mind Centre, Sydney Medical School, The University of Sydney, 94 Mallett St, Camperdown, NSW 2050, Australia.
| | - James Howells
- Brain and Mind Centre, Sydney Medical School, The University of Sydney, 94 Mallett St, Camperdown, NSW 2050, Australia.
| | - Yu-Ichi Noto
- Brain and Mind Centre, Sydney Medical School, The University of Sydney, 94 Mallett St, Camperdown, NSW 2050, Australia.
| | - Steve Vucic
- Departments of Neurology and Neurophysiology, Westmead Hospital, The University of Sydney, NSW, Australia.
| | - Con Yiannikas
- Department of Neurology, Concord and Royal North Shore Hospitals, The University of Sydney, NSW, Australia.
| | - Susan E Tomlinson
- Sydney Medical School, University of Sydney, Sydney, Australia; Department of Neurology, St Vincent's Hospital, Sydney, Australia.
| | - William Huynh
- Brain and Mind Centre, Sydney Medical School, The University of Sydney, 94 Mallett St, Camperdown, NSW 2050, Australia.
| | - Neil G Simon
- St Vincent's Clinical School, University of New South Wales, NSW, Australia.
| | - Emily K Mathey
- Brain and Mind Centre, Sydney Medical School, The University of Sydney, 94 Mallett St, Camperdown, NSW 2050, Australia.
| | - Judith Spies
- Brain and Mind Centre, Sydney Medical School, The University of Sydney, 94 Mallett St, Camperdown, NSW 2050, Australia.
| | - John D Pollard
- Brain and Mind Centre, Sydney Medical School, The University of Sydney, 94 Mallett St, Camperdown, NSW 2050, Australia.
| | - Arun V Krishnan
- Prince of Wales Clinical School, University of New South Wales, NSW, Australia.
| | - Matthew C Kiernan
- Brain and Mind Centre, Sydney Medical School, The University of Sydney, 94 Mallett St, Camperdown, NSW 2050, Australia.
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20
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Mazzi G, Raineri A, Zucco M, Passadore P, Pomes A, Orazi B. Plasma-exchange in Chronic Peripheral Neurological Disorders. Int J Artif Organs 2018. [DOI: 10.1177/039139889902200109] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
We investigated 19 patients affected by chronic peripheral neurological disorders treated with therapeutic plasma exchange (TPE) to verify the efficacy of the therapeutic protocol used in these diseases. Every patient was clinically considered after 5 TPE. Those who showed an improvement started chemotherapy and continued TPE at the rate of 2 procedures/week for 2 weeks, then 1 procedure/week for 1 month and finally 1 procedure every 2 weeks for 2 months. Intravenous immunoglobulins (IVIg) were infused at the end of apheretic treatment in one of the patients affected by neurological disorders due to monoclonal gammopathy undetermined significance. HCV-positive patients with cryoglobulins were treated with α-interferon (α-IFN) for 6 months before TPE. Eleven patients (58%) had a symptomatic improvement, 2 (1.5%) stopped TPE treatment owing to side effects and 6 (31.5%) did not respond to apheretic therapy. In order to improve the advantages of TPE we suggest using IVIg at the end of apheretic therapy, while in HCV-positive patients, at least one year of α-IFN therapy is required before initiating TPE.
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Affiliation(s)
- G. Mazzi
- Servizio Immunotrasfusionale, Azienda Ospedaliera “S. Maria degli Angeli”, Pordenone - Italy
| | - A. Raineri
- Servizio Immunotrasfusionale, Azienda Ospedaliera “S. Maria degli Angeli”, Pordenone - Italy
| | - M. Zucco
- Divisione di Neurologia, Azienda Ospedaliera “S. Maria degli Angeli”, Pordenone - Italy
| | - P. Passadore
- Divisione di Neurologia, Azienda Ospedaliera “S. Maria degli Angeli”, Pordenone - Italy
| | - A. Pomes
- Divisione di Neurologia, Azienda Ospedaliera “S. Maria degli Angeli”, Pordenone - Italy
| | - B.M. Orazi
- Servizio Immunotrasfusionale, Azienda Ospedaliera “S. Maria degli Angeli”, Pordenone - Italy
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21
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Dalakas MC. Advances in the diagnosis, immunopathogenesis and therapies of IgM-anti-MAG antibody-mediated neuropathies. Ther Adv Neurol Disord 2018; 11:1756285617746640. [PMID: 29403542 PMCID: PMC5791554 DOI: 10.1177/1756285617746640] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Accepted: 11/16/2017] [Indexed: 11/17/2022] Open
Abstract
Polyneuropathy with immunoglobulin M (IgM) monoclonal gammopathy is the most common paraproteinemic neuropathy, comprising a clinicopathologically and immunologically distinct entity. The clinical spectrum spans from distal paresthesias and mild gait imbalance to more severe sensory ataxia, with falls and a varying degree of distal sensorimotor deficits. In approximately 75% of patients, the monoclonal IgM immunoreacts with myelin-associated glycoprotein (MAG) and sulfoglucuronyl glycosphingolipid (SGPG), or other peripheral nerve glycolipids that serve as antigens. These antibodies are considered pathogenic because IgM and complement are deposited on the myelin sheath, splitting the myelin lamellae, while adoptive transfer of patients’ IgM into susceptible host animals causes sensory ataxia and reproduces the human pathology. In spite of the apparently convincing pathogenicity of these antibodies, the response to immunotherapies remains suboptimal. Clorambuscil, cladibrine, cyclophospamide and intravenous immunoglobulin may help some patients but the benefits are minimal and transient. Open-label studies in >200 patients indicate that rituximab is helpful in 30–50% of these patients, even with long-term benefits, probably by suppressing IgM anti-MAG antibodies or inducing immunoregulatory T cells. Two controlled studies with rituximab did not however meet the primary endpoint, mostly because of the poor sensitivity of the scales used; they did however show statistical improvement in secondary endpoints and improved clinical functions in several patients. This review provides an overview of the clinical phenotypes and immunoreactivity of IgM to glycolipids or glycoproteins of peripheral nerve myelin, summarizes the progress on treatment with rituximab as a promising therapy, discusses the pitfalls of scales used, identifies possible biomarkers of response to therapy and highlights the promising new anti-B cell or target-specific immunotherapies.
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Affiliation(s)
- Marinos C Dalakas
- Neuroimmunology Unit, Department of Pathophysiology, National and Kapodistrian University of Athens Medical School, Athens, Greece
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22
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Selective in vivo removal of pathogenic anti-MAG autoantibodies, an antigen-specific treatment option for anti-MAG neuropathy. Proc Natl Acad Sci U S A 2017; 114:E3689-E3698. [PMID: 28416698 DOI: 10.1073/pnas.1619386114] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Anti-MAG (myelin-associated glycoprotein) neuropathy is a disabling autoimmune peripheral neuropathy caused by monoclonal IgM autoantibodies that recognize the carbohydrate epitope HNK-1 (human natural killer-1). This glycoepitope is highly expressed on adhesion molecules, such as MAG, present in myelinated nerve fibers. Because the pathogenicity and demyelinating properties of anti-MAG autoantibodies are well established, current treatments are aimed at reducing autoantibody levels. However, current therapies are primarily immunosuppressive and lack selectivity and efficacy. We therefore hypothesized that a significant improvement in the disease condition could be achieved by selectively neutralizing the pathogenic anti-MAG antibodies with carbohydrate-based ligands mimicking the natural HNK-1 glycoepitope 1. In an inhibition assay, a mimetic (2, mimHNK-1) of the natural HNK-1 epitope blocked the interaction of MAG with pathogenic IgM antibodies from patient sera but with only micromolar affinity. Therefore, considering the multivalent nature of the MAG-IgM interaction, polylysine polymers of different sizes were substituted with mimetic 2. With the most promising polylysine glycopolymer PL84(mimHNK-1)45 the inhibitory effect on patient sera could be improved by a factor of up to 230,000 per epitope, consequently leading to a low-nanomolar inhibitory potency. Because clinical studies indicate a correlation between the reduction of anti-MAG IgM levels and clinical improvement, an immunological surrogate mouse model for anti-MAG neuropathy producing high levels of anti-MAG IgM was developed. The observed efficient removal of these antibodies with the glycopolymer PL84(mimHNK-1)45 represents an important step toward an antigen-specific therapy for anti-MAG neuropathy.
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23
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Rosenbaum E, Marks D, Raza S. Diagnosis and management of neuropathies associated with plasma cell dyscrasias. Hematol Oncol 2017; 36:3-14. [PMID: 28397326 DOI: 10.1002/hon.2417] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 02/14/2017] [Accepted: 03/06/2017] [Indexed: 12/16/2022]
Abstract
Neuropathies associated with plasma cell dyscrasias are a major cause of morbidity for patients managed by medical oncologists. Because of similarities in clinical presentation and on nerve conduction studies, identifying the underlying disease leading to a paraproteinemic neuropathy can often be difficult. In addition, the degree of neurologic deficit does not strictly correlate with the extent of abnormalities on common clinical laboratory testing. Fortunately, with increasing understanding into the biologic mechanisms of underlying hematologic diseases, additional biomarkers have recently been developed, thus improving our diagnostic capacity. Neuropathies associated with plasma cells dyscrasias are seen with Monoclonal gammopathy of undetermined significance (MGUS) particularly IgM subtype, followed by IgG and IgA MGUS, multiple myeloma, Waldenström's macroglobulinemia, amyloid, Castleman's disease, and POEMS syndrome. The mechanisms of neuronal injury associated with plasma cell dyscrasia vary based on underlying diagnosis and include malignant infiltration, immune-mediated antibody deposition, or local compression of nerve roots. The polyneuropathies are frequently demyelinating, although axonal and mixed neuropathies can also be seen. As demonstrated by the cases included in this review, patients frequently present with symmetric sensory disturbance, followed by progressive motor weakness. Unfortunately, because of the complexity of diagnostic testing, patients are frequently examined late, often after receiving several ineffective therapies. The aim of this case-based review is to provide clinicians with insight on how to properly recognize these atypical neuropathies and send the appropriate diagnostic work, increasing the likelihood of accurately classify the patient's underlying hematologic disorder.
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Affiliation(s)
- Evan Rosenbaum
- Division of Hematology & Oncology, Columbia University Medical Center, New York, NY, USA
| | - Douglas Marks
- Division of Hematology & Oncology, Columbia University Medical Center, New York, NY, USA
| | - Shahzad Raza
- Division of Hematology & Oncology, Columbia University Medical Center, New York, NY, USA
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24
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Lunn MPT, Nobile‐Orazio E. Immunotherapy for IgM anti-myelin-associated glycoprotein paraprotein-associated peripheral neuropathies. Cochrane Database Syst Rev 2016; 10:CD002827. [PMID: 27701752 PMCID: PMC6457998 DOI: 10.1002/14651858.cd002827.pub4] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Serum monoclonal anti-myelin-associated glycoprotein (anti-MAG) antibodies may be pathogenic in some people with immunoglobulin M (IgM) paraprotein and demyelinating neuropathy. Immunotherapies aimed at reducing the level of these antibodies might be expected to be beneficial. This is an update of a review first published in 2003 and previously updated in 2006 and 2012. OBJECTIVES To assess the effects of immunotherapy for IgM anti-MAG paraprotein-associated demyelinating peripheral neuropathy. SEARCH METHODS On 1 February 2016 we searched the Cochrane Neuromuscular Specialised Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase for randomised controlled trials (RCTs). We also checked trials registers and bibliographies, and contacted authors and experts in the field. SELECTION CRITERIA We included randomised controlled trials (RCTs) or quasi-RCTs involving participants of any age treated with any type of immunotherapy for anti-MAG antibody-associated demyelinating peripheral neuropathy with monoclonal gammopathy of undetermined significance and of any severity.Our primary outcome measures were numbers of participants improved in disability assessed with either or both of the Neuropathy Impairment Scale (NIS) or the modified Rankin Scale (mRS) at six months after randomisation. Secondary outcome measures were: mean improvement in disability, assessed with either the NIS or the mRS, 12 months after randomisation; change in impairment as measured by improvement in the 10-metre walk time, change in a validated linear disability measure such as the Rasch-built Overall Disability Scale (R-ODS) at six and 12 months after randomisation, change in subjective clinical scores and electrophysiological parameters at six and 12 months after randomisation; change in serum IgM paraprotein concentration or anti-MAG antibody titre at six months after randomisation; and adverse effects of treatments. DATA COLLECTION AND ANALYSIS We followed standard methodological procedures expected by Cochrane. MAIN RESULTS We identified eight eligible trials (236 participants), which tested intravenous immunoglobulin (IVIg), interferon alfa-2a, plasma exchange, cyclophosphamide and steroids, and rituximab. Two trials of IVIg (22 and 11 participants, including 20 with antibodies against MAG), had comparable interventions and outcomes, but both were short-term trials. We also included two trials of rituximab with comparable interventions and outcomes.There were very few clinical or statistically significant benefits of the treatments used on the outcomes predefined for this review, but not all the predefined outcomes were used in every included trial and more responsive outcomes are being developed. A well-performed trial of IVIg, which was at low risk of bias, showed a statistical benefit in terms of improvement in mRS at two weeks and 10-metre walk time at four weeks, but these short-term outcomes are of questionable clinical significance. Cyclophosphamide failed to show any benefit in the single trial's primary outcome, and showed a barely significant benefit in the primary outcome specified here, but some toxic adverse events were identified.Two trials of rituximab (80 participants) have been published, one of which (26 participants) was at high risk of bias. In the meta-analysis, although the data are of low quality, rituximab is beneficial in improving disability scales (Inflammatory Neuropathy Cause and Treatment (INCAT) improved at eight to 12 months (risk ratio (RR) 3.51, 95% confidence interval (CI) 1.30 to 9.45; 73 participants)) and significantly more participants improve in the global impression of change score (RR 1.86, 95% CI 1.27 to 2.71; 70 participants). Other measures did not improve significantly, but wide CIs do not preclude some effect. Reported adverse effects of rituximab were few, and mostly minor.There were few serious adverse events in the other trials. AUTHORS' CONCLUSIONS There is inadequate reliable evidence from trials of immunotherapies in anti-MAG paraproteinaemic neuropathy to form an evidence base supporting any particular immunotherapy treatment. IVIg has a statistically but probably not clinically significant benefit in the short term. The meta-analysis of two trials of rituximab provides, however, low-quality evidence of a benefit from this agent. The conclusions of this meta-analysis await confirmation, as one of the two included studies is of very low quality. We require large well-designed randomised trials of at least 12 months' duration to assess existing or novel therapies, preferably employing unified, consistent, well-designed, responsive, and valid outcome measures.
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Affiliation(s)
- Michael PT Lunn
- National Hospital for Neurology and NeurosurgeryDepartment of Neurology and MRC Centre for Neuromuscular DiseasesQueen SquareLondonUKWC1N 3BG
| | - Eduardo Nobile‐Orazio
- Milan UniversityIRCCS Humanitas Clinical Institute, Neurology 2Istituto Clinico HumanitasVia Manzoni 56, RozzanoMilanItaly20089
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Alexopoulos H, Biba A, Dalakas MC. Anti-B-Cell Therapies in Autoimmune Neurological Diseases: Rationale and Efficacy Trials. Neurotherapeutics 2016; 13:20-33. [PMID: 26566961 PMCID: PMC4720683 DOI: 10.1007/s13311-015-0402-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
B cells have an ever-increasing role in the etiopathology of a number of autoimmune neurological disorders, acting as antibody-producing cells and, most importantly, as sensors, coordinators, and regulators of the immune response. B cells, among other functions, regulate the T-cell activation process through their participation in antigen presentation and production of cytokines. The availability of monoclonal antibodies or fusion proteins against B-cell surface molecules or B-cell trophic factors bestows a rational approach for treating autoimmune neurological disorders, even when T cells are the main effector cells. This review summarizes basic aspects of B-cell biology, discusses the role(s) of B cells in neurological autoimmunity, and presents anti-B-cell drugs that are either currently on the market or are expected to be available in the near future for treating neurological autoimmune disorders.
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Affiliation(s)
- Harry Alexopoulos
- Neuroimmunology Unit, Department of Pathophysiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Angie Biba
- Neuroimmunology Unit, Department of Pathophysiology, Faculty of Medicine, National and Kapodistrian University of Athens, Athens, Greece
| | - Marinos C Dalakas
- Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA.
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Bradl M, Lassmann H. Neurologic autoimmunity: mechanisms revealed by animal models. HANDBOOK OF CLINICAL NEUROLOGY 2016; 133:121-43. [PMID: 27112675 DOI: 10.1016/b978-0-444-63432-0.00008-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Over the last decade, neurologic autoimmunity has become a major consideration in the diagnosis and management of patients with many neurologic presentations. The nature of the associated antibodies and their targets has led to appreciation of the importance of the accessibility of the target antigen to antibodies, and a partial understanding of the different mechanisms that can follow antibody binding. This chapter will first describe the basic principles of autoimmune inflammation and tissue damage in the central and peripheral nervous system, and will then demonstrate what has been learnt about neurologic autoimmunity from circumstantial clinical evidence and from passive, active, and occasionally spontaneous or genetic animal models. It will cover neurologic autoimmune diseases ranging from disorders of neuromuscular transmission, peripheral and ganglionic neuropathy, to diseases of the central nervous system, where autoantibodies are either pathogenic and cause destruction or changes in function of their targets, where they are harmless bystanders of T-cell-mediated tissue damage, or are not involved at all. Finally, this chapter will summarize the relevance of current animal models for studying the different neurologic autoimmune diseases, and it will identify aspects where future animal models need to be improved to better reflect the disease reality experienced by affected patients, e.g., the chronicity or the relapsing/remitting nature of their disease.
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Affiliation(s)
- Monika Bradl
- Department of Neuroimmunology, Center for Brain Research, Medical University Vienna, Vienna, Austria.
| | - Hans Lassmann
- Department of Neuroimmunology, Center for Brain Research, Medical University Vienna, Vienna, Austria
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Mariotto S, Ferrari S, Monaco S. HCV-related central and peripheral nervous system demyelinating disorders. ACTA ACUST UNITED AC 2015; 13:299-304. [PMID: 25198705 PMCID: PMC4428084 DOI: 10.2174/1871528113666140908113841] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 08/25/2014] [Accepted: 09/01/2014] [Indexed: 12/20/2022]
Abstract
Chronic infection with hepatitis C virus (HCV) is associated with a large spectrum of extrahepatic
manifestations (EHMs), mostly immunologic/rheumatologic in nature owing to B-cell proliferation and clonal expansion.
Neurological complications are thought to be immune-mediated or secondary to invasion of neural tissues by HCV, as
postulated in transverse myelitis and encephalopathic forms. Primarily axonal neuropathies, including sensorimotor
polyneuropathy, large or small fiber sensory neuropathy, motor polyneuropathy, mononeuritis, mononeuritis multiplex, or
overlapping syndrome, represent the most common neurological complications of chronic HCV infection. In addition, a
number of peripheral demyelinating disorders are encountered, such as chronic inflammatory demyelinating
polyneuropathy, the Lewis-Sumner syndrome, and cryoglobulin-associated polyneuropathy with demyelinating features.
The spectrum of demyelinating forms also includes rare cases of iatrogenic central and peripheral nervous system
disorders, occurring during treatment with pegylated interferon. Herein, we review HCV-related demyelinating
conditions, and disclose the novel observation on the significantly increased frequency of chronic demyelinating
neuropathy with anti-myelin-associated glycoprotein antibodies in a cohort of 59 consecutive patients recruited at our
institution. We also report a second case of neuromyelitis optica with serum IgG autoantibody against the water channel
aquaporin-4. The prompt recognition of these atypical and underestimated complications of HCV infection is of crucial
importance in deciding which treatment option a patient should be offered.
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Affiliation(s)
| | | | - Salvatore Monaco
- Department of Neurological and Movement Sciences, University of Verona, Policlinico G.B. Rossi, P.le L.A. Scuro 10, 37134 Verona, Italy.
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Campagnolo M, Ferrari S, Dalla Torre C, Cabrini I, Cacciavillani M, Lucchetta M, Ruggero S, Toffanin E, Cavallaro T, Briani C. Polyneuropathy with anti-sulfatide and anti-MAG antibodies: Clinical, neurophysiological, pathological features and response to treatment. J Neuroimmunol 2015; 281:1-4. [DOI: 10.1016/j.jneuroim.2015.02.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Accepted: 02/28/2015] [Indexed: 10/23/2022]
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Pathogenesis of immune-mediated neuropathies. Biochim Biophys Acta Mol Basis Dis 2015; 1852:658-66. [DOI: 10.1016/j.bbadis.2014.06.013] [Citation(s) in RCA: 79] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2014] [Accepted: 06/09/2014] [Indexed: 11/20/2022]
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Autoimmune Manifestations in Patients With Waldenström Macroglobulinemia. CLINICAL LYMPHOMA MYELOMA & LEUKEMIA 2014; 14:456-9. [DOI: 10.1016/j.clml.2014.04.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2013] [Revised: 12/31/2013] [Accepted: 04/30/2014] [Indexed: 12/25/2022]
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Lucchetta M, Padua L, Granata G, Luigetti M, Campagnolo M, Dalla Torre C, Coraci D, Sabatelli M, Briani C. Nerve ultrasound findings in neuropathy associated with anti-myelin-associated glycoprotein antibodies. Eur J Neurol 2014; 22:193-202. [PMID: 25174585 DOI: 10.1111/ene.12554] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 07/16/2014] [Indexed: 12/30/2022]
Abstract
BACKGROUND AND PURPOSE No systematic nerve ultrasound (US) studies on patients with neuropathy and anti-myelin-associated glycoprotein (anti-MAG) antibodies are available. PATIENTS AND METHODS Twenty-eight patients (18 men, 10 women, mean age 69.2 ± 10.9 years; mean disease duration 6.9 years) with anti-MAG neuropathy underwent nerve US. Echotexture, nerve cross-sectional area (CSA) and intra-nerve and inter-nerve CSA variability were assessed. The frequency (number of nerves with enlarged CSA, 'enlarged nerves sum score') and distribution (proximal versus distal, arms versus legs, symmetry) of US abnormalities were considered. Controls included two groups: four patients with immunoglobulin M (IgM) paraproteinaemic neuropathy without anti-MAG antibodies and five with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) associated with IgM paraprotein. RESULTS In all, 26/28 patients had increased CSA (23 with at least one nerve outside entrapment sites). Intra-nerve CSA variability was abnormal in 21/28 patients (in 14 for increased nerve CSA outside entrapment sites). Inter-nerve CSA variability was abnormal in 16 patients (of whom half for CSA increase out of entrapment sites). The enlarged nerves sum score in anti-MAG neuropathy patients was greater than in MAG-negative paraproteinaemic neuropathies and lower than in CIDP. Intra-nerve variability appeared instead similar in anti-MAG and controls. No correlation was found between US findings and Inflammatory Neuropathy Cause and Treatment Group (INCAT) disability score or disease duration. DISCUSSION Amongst the different measures to assess the US pattern (symmetry/asymmetry, proximal/distal distribution and sum score), the enlarged nerves sum score was the most useful for differentiating the three groups of patients with demyelinating neuropathies and may contribute to diagnosis in a typical cases.
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Affiliation(s)
- M Lucchetta
- Department of Neurosciences, SNPSRR, University of Padova, Padova, Italy
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Dalakas MC. Pathophysiology of autoimmune polyneuropathies. Presse Med 2013; 42:e181-92. [DOI: 10.1016/j.lpm.2013.01.058] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2013] [Accepted: 01/14/2013] [Indexed: 11/16/2022] Open
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Dalakas MC. Autoimmune peripheral neuropathies. Clin Immunol 2013. [DOI: 10.1016/b978-0-7234-3691-1.00080-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Abstract
The association of neuropathy with monoclonal gammopathy has been known for several years, even if the clinical and pathogenetic relevance of this association is not completely defined. This is not a marginal problem since monoclonal gammopathy is present in 1-3% of the population above 50 years in whom it is often asymptomatic, and in at least 8% of patients is associated with a symptomatic neuropathy, representing one of the leading causes of neuropathy in aged people. Monoclonal gammopathy may result from malignant lymphoproliferative diseases including multiple myeloma or solitary plasmocytoma, Waldenström's macroglobulinemia (WM), other IgM-secreting lymphoma or chronic lymphocytic leukemia, and primary systemic amyloidosis (AL). In most instances it is not associated with any of these disorders and is defined monoclonal gammopathy of undetermined significance (MGUS) for its possible, though infrequent, evolution into malignant forms. Several data support the pathogenetic role of the monoclonal gammopathy in the neuropathy particularly when of IgM isotype where IgM reactivity to several neural antigens has been reported. Increased levels of VEGF have been implicated in POEMS syndrome. However, there are as yet no defined therapies for these neuropathies, as their efficacy has not been confirmed in randomized trials.
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Affiliation(s)
- Eduardo Nobile-Orazio
- 2nd Neurology, Department of Translational Medicine, Milan University, IRCCS Humanitas Clinical Institute, Rozzano, Milan, Italy.
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Lunn MPT, Nobile-Orazio E. Immunotherapy for IgM anti-myelin-associated glycoprotein paraprotein-associated peripheral neuropathies. Cochrane Database Syst Rev 2012:CD002827. [PMID: 22592686 DOI: 10.1002/14651858.cd002827.pub3] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Serum monoclonal anti-myelin-associated glycoprotein antibodies may be pathogenic in some people with immunoglobulin M (IgM) paraprotein and demyelinating neuropathy. Immunotherapies aimed at reducing the level of these antibodies might be expected to be beneficial. This is an update of a review first published in 2003 and previously updated in 2006. OBJECTIVES To assess the effects of immunotherapy for IgM anti-myelin-associated glycoprotein paraprotein-associated demyelinating peripheral neuropathy. SEARCH METHODS We searched the Cochrane Neuromuscular Disease Group Specialized Register 6 June 2011), CENTRAL (2011, Issue 2), MEDLINE (January 1966 to May 2011) and EMBASE (January 1980 to May 2011) for controlled trials. We also checked bibliographies and contacted authors and experts in the field. SELECTION CRITERIA We included randomised or quasi-randomised controlled trials involving participants of any age treated with any type of immunotherapy for anti-myelin-associated glycoprotein antibody-associated demyelinating peripheral neuropathy with monoclonal gammopathy of undetermined significance and of any severity.Our primary outcome measure was change in the Neuropathy Impairment Scale or Modified Rankin Scale at six months after randomisation. Secondary outcome measures were: Neuropathy Impairment Scale or the Modified Rankin Score at 12 months after randomisation; 10-metre walk time, subjective clinical scores and electrophysiological parameters at six and 12 months after randomisation; IgM paraprotein levels and anti-myelin-associated glycoprotein antibody titres at six months after randomisation; and adverse effects of treatments. DATA COLLECTION AND ANALYSIS The two authors independently selected studies. Two authors independently assessed the risk of bias in included studies. MAIN RESULTS We identified seven eligible trials (182 participants), which tested intravenous immunoglobulin, alfa interferon alfa-2a, plasma exchange, cyclophosphamide and steroids, and rituximab. Only two trials, of intravenous immunoglobulin (with 33 participants, including 20 with antibodies against myelin-associated glycoprotein), had comparable interventions and outcomes, but both were short-term trials.There were no clinical or statistically significant benefits of the treatments used on the outcomes predefined for this review, but not all the predefined outcomes were used in every included trial. Intravenous immunoglobulin showed a statistical benefit in terms of improvement in Modified Rankin Scale at two weeks and 10-metre walk time at four weeks. Cyclophosphamide failed to show any benefit in the trial's primary outcome, and showed a barely significant benefit in the primary outcome specified here, but some toxic adverse events were identified. A trial of rituximab was of poor methodological quality with a high risk of bias and a further larger study is awaited. Serious adverse events were few in the other trials. AUTHORS' CONCLUSIONS There is inadequate reliable evidence from trials of immunotherapies in anti-myelin-associated glycoprotein paraproteinaemic neuropathy to form an evidence base supporting any particular immunotherapy treatment. There is very low quality evidence of benefit from rituximab. Large well designed randomised trials of at least six to 12 months duration are required to assess existing or novel therapies, preferably employing unified, consistent, well designed, responsive and valid outcome measures.
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Affiliation(s)
- Michael P T Lunn
- Department of Neurology and MRC Centre for Neuromuscular Diseases, National Hospital for Neurology and Neurosurgery, London, UK.
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Bayat E, Kelly JJ. Neurological complications in plasma cell dyscrasias. HANDBOOK OF CLINICAL NEUROLOGY 2012; 105:731-46. [PMID: 22230530 DOI: 10.1016/b978-0-444-53502-3.00020-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Affiliation(s)
- Elham Bayat
- Department of Neurology, The George Washington University, Washington, DC, USA
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Morphological Progression of Myelin Abnormalities in IgM-Monoclonal Gammopathy of Undetermined Significance Anti-Myelin-Associated Glycoprotein Neuropathy. J Neuropathol Exp Neurol 2010; 69:1143-57. [DOI: 10.1097/nen.0b013e3181fa44af] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Collins MP, Periquet-Collins I, Sahenk Z, Kissel JT. Direct immunofluoresence in vasculitic neuropathy: Specificity of vascular immune deposits. Muscle Nerve 2010; 42:62-9. [DOI: 10.1002/mus.21639] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Pedersen ED, Løberg EM, Vege E, Daha MR, Maehlen J, Mollnes TE. In situ deposition of complement in human acute brain ischaemia. Scand J Immunol 2009; 69:555-62. [PMID: 19439017 DOI: 10.1111/j.1365-3083.2009.02253.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Experimental animal models indicate that complement contributes to tissue damage during brain ischaemia and stroke, but limited data are available for a role of the complement in human stroke. We, therefore, evaluated whether acute ischaemia leads to complement activation in human brain. Indirect immunohistochemical staining was performed on paraffin-embedded, formalin-fixed human brain from 10 patients and 10 controls. Complement components C1q, C3c and C4d were detected in all ischaemic lesions, suggesting activation via the classical pathway. C9, C-reactive protein and IgM were detected in necrotic zones. Marked CD59 and weak CD55 expression were found in normal brains, but these complement regulators were virtually absent in ischaemic lesions. Modest amounts of mannose-binding lectin (MBL), MBL-associated serine protease-2 and factor B were found in both ischaemic lesions and controls. These data suggest that increased deposition of complement components combined with decreased expression of complement regulators is a possible mechanism of tissue damage during ischaemia in human brain.
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Affiliation(s)
- E D Pedersen
- Faculty of Medicine, Institute of Immunology, Rikshospitalet University Hospital, University of Oslo, Oslo, Norway.
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Nobile-Orazio E. Antigenic Determinants in IgM Paraprotein-Related Neuropathies. ACTA ACUST UNITED AC 2009; 9:107-9. [DOI: 10.3816/clm.2009.n.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Autoimmune peripheral neuropathies. Clin Immunol 2008. [DOI: 10.1016/b978-0-323-04404-2.10066-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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44
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Benedetti L, Briani C, Grandis M, Vigo T, Gobbi M, Ghiglione E, Carpo M, Cocito D, Caporale CM, Sormani MP, Mancardi GL, Nobile-Orazio E, Schenone A. Predictors of response to rituximab in patients with neuropathy and anti-myelin associated glycoprotein immunoglobulin M. J Peripher Nerv Syst 2007; 12:102-7. [PMID: 17565535 DOI: 10.1111/j.1529-8027.2007.00129.x] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We evaluated the efficacy and safety of rituximab in an open-label, uncontrolled study of 13 patients with polyneuropathy associated with antibodies to myelin-associated glycoprotein (MAG) and correlated the response to therapy with clinical and laboratory features. One year after rituximab therapy, anti-MAG immunoglobulin M (IgM) titers were significantly reduced. At that time, eight patients (62%) had improved in both the inflammatory neuropathy cause and treatment (INCAT) sensory sumscore and the Medical Research Council sumscore for muscle strength and seven of them also in the INCAT disability score. The improvement in the mean INCAT sensory sumscore was significant at 12 months and correlated with lower anti-MAG antibody at entry and at follow-up. This study suggests that rituximab may be efficacious in patients with anti-MAG associated neuropathy and particularly on sensory impairment and in those with moderately elevated antibody titers. These findings suggest that antibody reduction below a critical level may be necessary to achieve clinical improvement.
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Affiliation(s)
- Luana Benedetti
- Department of Neurosciences, Ophthalmology and Genetics, University of Genova, Genova, Italy.
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Abstract
Paraproteinemia frequently is associated with peripheral neuropathy. The clinical manifestations can be protean owing to the potential for multiple organ involvement. A methodical diagnostic approach to patients who have a plasma cell dyscrasia and neuropathy is necessary to ensure the appropriate detection of more widespread systemic involvement.
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Affiliation(s)
- Justin Y Kwan
- Department of Neurology, Baylor College of Medicine, 6550 Fannin, Suite 1801, Houston, TX 77030, USA.
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Lunn MPT, Nobile-Orazio E. Immunotherapy for IgM anti-myelin-associated glycoprotein paraprotein-associated peripheral neuropathies. Cochrane Database Syst Rev 2006:CD002827. [PMID: 16625561 DOI: 10.1002/14651858.cd002827.pub2] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Serum monoclonal anti-myelin associated glycoprotein antibodies may be pathogenic in some people with IgM paraprotein and demyelinating neuropathy. Immunotherapies aimed at reducing the level of these antibodies might be expected to be beneficial. OBJECTIVES To examine the efficacy of any form of immunotherapy in reducing disability and impairment resulting from IgM anti-myelin associated glycoprotein paraprotein-associated demyelinating peripheral neuropathy. SEARCH STRATEGY We searched the Cochrane Neuromuscular Disease Group Register (March 2005), MEDLINE (January 1966 to March 2005) and EMBASE (January 1980 to March 2005) for controlled trials. We also checked bibliographies and contacted authors and experts in the field. SELECTION CRITERIA We included randomised or quasi-randomised controlled trials of participants of any age treated with any type of immunotherapy for anti-myelin-associated glycoprotein antibody associated demyelinating peripheral neuropathy with monoclonal gammopathy of undetermined significance of any severity. Our primary outcome measure was change in the Neuropathy Impairment Scale or Modified Rankin Scale at six months after randomisationSecondary outcome measures were: Neuropathy Impairment Scale or the Modified Rankin Score at 12 months after randomisation; ten-metre walk time, subjective clinical scores and electrophysiological parameters at six and 12 months after randomisation; IgM paraprotein levels and anti-myelin associated glycoprotein antibody titres at six months after randomisation and adverse effects of treatments. DATA COLLECTION AND ANALYSIS We identified eight possible trials. Of these, five randomised controlled trials were included after discussion between the authors. One author extracted and the other checked the data. No missing data could be obtained from trial authors. MAIN RESULTS The five eligible trials (97 participants) tested intravenous immunoglobulin, interferon-alpha or plasma exchange. Only two, of intravenous immunoglobulin, had comparable interventions and outcomes but both were short-term. There were no significant benefits of the treatments used in the outcomes predefined for this review, but not all the predefined outcomes were used in every included trial. Intravenous immunoglobulin showed benefits in terms of improvement in Modified Rankin Scale at two weeks and 10-metre walk time at four weeks. Serious adverse effects of intravenous immunoglobulin are known to occur from observational studies but none were encountered in these trials. AUTHORS' CONCLUSIONS There is inadequate reliable evidence from trials of immunotherapies in anti-myelin associated glycoprotein paraproteinaemic neuropathy to recommend any particular immunotherapy treatment. Intravenous immunoglobulin is relatively safe and may produce some short-term benefit. Large well-designed randomised trials of at least six to 12 months duration are required to assess existing or novel therapies.
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Affiliation(s)
- M P T Lunn
- National Hospital for Neurology and Neurosurgery, Department of Neurology, Queen Square, London, UK, WC1N 3BG.
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Levine T, Pestronk A, Florence J, Al-Lozi MT, Lopate G, Miller T, Ramneantu I, Waheed W, Stambuk M, Stone MJ, Choksi R. Peripheral neuropathies in Waldenström's macroglobulinaemia. J Neurol Neurosurg Psychiatry 2006; 77:224-8. [PMID: 16421127 PMCID: PMC2077569 DOI: 10.1136/jnnp.2005.071175] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
OBJECTIVE We sought to determine the prevalence, clinical features, and laboratory characteristics of polyneuropathies in Waldenström's macroglobulinaemia (WM), a malignant bone marrow disorder with lymphocytes that produce monoclonal IgM. METHODS We prospectively studied 119 patients with WM and 58 controls. Medical history was taken, and neurological examinations, electrodiagnostic tests, and serum studies were performed by different examiners who were blinded to results except the diagnosis of WM. RESULTS Polyneuropathy symptoms, including discomfort and sensory loss in the legs, occurred more frequently (p<0.001) in patients with WM (47%) than in controls (9%). Patients with WM had 35% lower quantitative vibration scores, and more frequent pin loss (3.4 times) and gait disorders (5.5 times) than controls (all p<0.001). Patients with IgM binding to sulphatide (5% of WM) had sensory axon loss; those with IgM binding to myelin associated glycoprotein (MAG) (4% of WM) had sensorimotor axon loss and demyelination. Patients with WM with IgM binding to sulphatide (p<0.005) or MAG (p<0.001) had more severe sensory axon loss than other patients with WM. Demyelination occurred in 4% of patients with WM with no IgM binding to MAG. Age related reductions in vibration sense and sural SNAP amplitudes were similar ( approximately 30%) in WM and controls. CONCLUSIONS Peripheral nerve symptoms and signs occur more frequently in patients with WM than controls, involve sensory modalities, and are often associated with gait disorders. IgM binding to MAG or sulphatide is associated with a further increase in the frequency and severity of peripheral nerve involvement. Age related changes, similar to those in controls, add to the degree of reduced nerve function in patients with WM.
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Affiliation(s)
- T Levine
- Phoenix Neurological Associates, AZ, USA
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Lombardi R, Erne B, Lauria G, Pareyson D, Borgna M, Morbin M, Arnold A, Czaplinski A, Fuhr P, Schaeren-Wiemers N, Steck AJ. IgM deposits on skin nerves in anti-myelin-associated glycoprotein neuropathy. Ann Neurol 2005; 57:180-7. [PMID: 15668968 DOI: 10.1002/ana.20364] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Anti-myelin-associated glycoprotein (anti-MAG) neuropathy is a chronic demyelinating neuropathy with predominant involvement of large sensory fibers and deposits of IgM and complement on sural nerve myelinated fibers. We assessed the presence of IgM deposits on skin myelinated nerve fibers and the involvement of unmyelinated axons in anti-MAG neuropathy. Skin biopsies were performed in 14 patients with anti-MAG neuropathy, in 8 patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), and in 2 patients with IgM paraproteinemic neuropathy. Biopsies were taken at the proximal thigh in 20 patients, at the distal leg in 21 patients, at the proximal arm in 13 patients, and at the hand or fingertip in 10 patients. We found IgM deposits on dermal myelinated fibers in all anti-MAG neuropathy patients, with a greater prevalence at the distal site of the extremities. Deposits were located throughout the length of the fibers and at the paranodal loops. CIDP and IgM paraproteinemic neuropathies did not show any deposit of IgM. Anti-MAG neuropathy and CIPD patients showed a decrease in epidermal nerve fiber density reflecting an associated axonal loss. In anti-MAG neuropathy, both large- and small-diameter nerve fibers are affected, and specific deposits of IgM are found on skin myelinated nerve fibers.
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Affiliation(s)
- Raffaella Lombardi
- Neurobiology Unit, Department of Research and Neurology, University Hospital of Basel, Basel, Switzerland
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Latov N, Renaud S. Effector mechanisms in anti-MAG antibody-mediated and other demyelinating neuropathies. J Neurol Sci 2004; 220:127-9. [PMID: 15140620 DOI: 10.1016/j.jns.2004.03.012] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Norman Latov
- Department of Neurology and Neuroscience, Peripheral Neuropathy Center, Weill Medical College of Cornell University, New York, NY 10022, USA.
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Bonetti B, Panzeri L, Carner M, Zamboni G, Rizzuto N, Moretto G. Human neoplastic Schwann cells: changes in the expression of neurotrophins and their low‐affinity receptor p75. Neuropathol Appl Neurobiol 2003. [DOI: 10.1111/j.1365-2990.1997.tb01312.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- B. Bonetti
- Sezione di Neurologia Clinica Dipartimento di Scienze Neurologiche e della Visione, ,
| | - L. Panzeri
- Sezione di Neurologia Clinica Dipartimento di Scienze Neurologiche e della Visione, ,
| | | | - G. Zamboni
- Istituto di Anatomia Patologica, Universita' di Verona, Italy
| | - N. Rizzuto
- Sezione di Neurologia Clinica Dipartimento di Scienze Neurologiche e della Visione, ,
| | - G. Moretto
- Sezione di Neurologia Clinica Dipartimento di Scienze Neurologiche e della Visione, ,
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