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Vélez-Santamaría V, Nedkova V, Díez L, Homedes C, Alberti MA, Casasnovas C. Eculizumab as a promising treatment in thymoma-associated myasthenia gravis. Ther Adv Neurol Disord 2020; 13:1756286420932035. [PMID: 32655688 PMCID: PMC7331764 DOI: 10.1177/1756286420932035] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 05/14/2020] [Indexed: 11/17/2022] Open
Abstract
Myasthenia gravis is a chronic autoimmune disorder caused by antibodies directed against the neuromuscular junction. Some patients may have an associated thymoma, which confers a worse prognosis. Eculizumab, a monoclonal antibody that inhibits the activation of terminal complement, has recently been approved for the treatment of refractory generalized myasthenia gravis. This is an early case report of thymoma-associated refractory myasthenia gravis successfully treated with eculizumab in a real-world setting.
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Affiliation(s)
- Valentina Vélez-Santamaría
- Neurometabolic Diseases Group, Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Spain, and Neurology Department, Bellvitge University Hospital, Barcelona, Spain
| | - Velina Nedkova
- Neurology Department, Bellvitge University Hospital, Barcelona, Spain
| | - Laura Díez
- Neurology Department, Bellvitge University Hospital, Barcelona, Spain
| | - Christian Homedes
- Neurology Department, Bellvitge University Hospital, Barcelona, Spain
| | - M Antonia Alberti
- Neurology Department, Bellvitge University Hospital, Barcelona, Spain
| | - Carlos Casasnovas
- Neurology Department, Neuromuscular Unit, Bellvitge University Hospital, n/n Feixa Llarga street, L'Hospitalet de Llobregat, Barcelona, 08906, Spain
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Abbott JA, Meyer-Schuman R, Lupo V, Feely S, Mademan I, Oprescu SN, Griffin LB, Alberti MA, Casasnovas C, Aharoni S, Basel-Vanagaite L, Züchner S, De Jonghe P, Baets J, Shy ME, Espinós C, Demeler B, Antonellis A, Francklyn C. Cover Image, Volume 39, Issue 3. Hum Mutat 2018. [DOI: 10.1002/humu.23405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Abbott JA, Meyer-Schuman R, Lupo V, Feely S, Mademan I, Oprescu SN, Griffin LB, Alberti MA, Casasnovas C, Aharoni S, Basel-Vanagaite L, Züchner S, De Jonghe P, Baets J, Shy ME, Espinós C, Demeler B, Antonellis A, Francklyn C. Substrate interaction defects in histidyl-tRNA synthetase linked to dominant axonal peripheral neuropathy. Hum Mutat 2018; 39:415-432. [PMID: 29235198 PMCID: PMC5983030 DOI: 10.1002/humu.23380] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 12/01/2017] [Accepted: 12/07/2017] [Indexed: 11/09/2022]
Abstract
Histidyl-tRNA synthetase (HARS) ligates histidine to cognate tRNA molecules, which is required for protein translation. Mutations in HARS cause the dominant axonal peripheral neuropathy Charcot-Marie-Tooth disease type 2W (CMT2W); however, the precise molecular mechanism remains undefined. Here, we investigated three HARS missense mutations associated with CMT2W (p.Tyr330Cys, p.Ser356Asn, and p.Val155Gly). The three mutations localize to the HARS catalytic domain and failed to complement deletion of the yeast ortholog (HTS1). Enzyme kinetics, differential scanning fluorimetry (DSF), and analytical ultracentrifugation (AUC) were employed to assess the effect of these substitutions on primary aminoacylation function and overall dimeric structure. Notably, the p.Tyr330Cys, p.Ser356Asn, and p.Val155Gly HARS substitutions all led to reduced aminoacylation, providing a direct connection between CMT2W-linked HARS mutations and loss of canonical ARS function. While DSF assays revealed that only one of the variants (p.Val155Gly) was less thermally stable relative to wild-type, all three HARS mutants formed stable dimers, as measured by AUC. Our work represents the first biochemical analysis of CMT-associated HARS mutations and underscores how loss of the primary aminoacylation function can contribute to disease pathology.
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Affiliation(s)
- Jamie A. Abbott
- Department of Biochemistry, University of Vermont, College of Medicine, Burlington, Vermont
| | - Rebecca Meyer-Schuman
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan
| | - Vincenzo Lupo
- Unit of Genetics and Genomics of Neuromuscular Disorders, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain
| | - Shawna Feely
- Department of Neurology, University of Iowa Hospitals and Clinics, Iowa City, Iowa
| | - Inès Mademan
- Neurogenetics Group, Center for Molecular Neurology, VIB, Antwerp, Belgium
- Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerpen, Belgium
| | - Stephanie N. Oprescu
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan
| | - Laurie B. Griffin
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan
- Medical Scientist Training Program, University of Michigan Medical School, Ann Arbor, Michigan
| | - M. Antonia Alberti
- Department of Neurology, Hospital Universitario de Bellvitge, Barcelona, Spain
| | - Carlos Casasnovas
- Department of Neurology, Hospital Universitario de Bellvitge, Barcelona, Spain
| | - Sharon Aharoni
- Institute of Child Neurology, Schneider Children’s Medical Center of Israel, Petah Tikva, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Lina Basel-Vanagaite
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Raphael Recanati Genetic Institute, Rabin Medical Center, Beilinson Campus, Petah Tikva, Israel
- Pediatric Genetics Unit, Schneider Children’s Medical Center, Petah Tikva, Israel
- Felsenstein Medical Research Center, Rabin Medical Center, Petah Tikva, Israel
| | - Stephan Züchner
- Dr John T McDonald Foundation Department of Human Genetics & John P Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, Florida
| | - Peter De Jonghe
- Neurogenetics Group, Center for Molecular Neurology, VIB, Antwerp, Belgium
- Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerpen, Belgium
- Department of Neurology, Antwerp University Hospital, Antwerpen, Belgium
| | - Jonathan Baets
- Neurogenetics Group, Center for Molecular Neurology, VIB, Antwerp, Belgium
- Laboratory of Neuromuscular Pathology, Institute Born-Bunge, University of Antwerp, Antwerpen, Belgium
- Department of Neurology, Antwerp University Hospital, Antwerpen, Belgium
| | - Michael E. Shy
- Department of Neurology, University of Iowa Hospitals and Clinics, Iowa City, Iowa
| | - Carmen Espinós
- Unit of Genetics and Genomics of Neuromuscular Disorders, Centro de Investigación Príncipe Felipe (CIPF), Valencia, Spain
| | - Borries Demeler
- Department of Biochemistry, The University of Texas Health Sciences at San Antonio, San Antonio, Texas
| | - Anthony Antonellis
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, Michigan
| | - Christopher Francklyn
- Department of Biochemistry, University of Vermont, College of Medicine, Burlington, Vermont
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Alberti MA, Povedano M, Montero J, Casasnovas C. Early electrophysiological findings in Fisher-Bickerstaff syndrome. Neurologia 2017; 35:40-45. [PMID: 28888467 DOI: 10.1016/j.nrl.2017.05.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 05/15/2017] [Accepted: 05/23/2017] [Indexed: 11/30/2022] Open
Abstract
INTRODUCTION The term Fisher-Bickerstaff syndrome (FBS) has been proposed to describe the clinical spectrum encompassing Miller-Fisher syndrome (MFS) and Bickerstaff brainstem encephalitis. The pathophysiology of FBS and the nature of the underlying neuropathy (demyelinating or axonal) are still subject to debate. This study describes the main findings of an early neurophysiological study on 12 patients diagnosed with FBS. PATIENTS AND METHODS Retrospective evaluation of clinical characteristics and electrophysiological findings of 12 patients with FBS seen in our neurology department within 10 days of disease onset. Follow-up electrophysiological studies were also evaluated, where available. RESULTS The most frequent electrophysiological finding, present in 5 (42%) patients, was reduced sensory nerve action potential (SNAP) amplitude in one or more nerves. Abnormalities were rarely found in motor neurography, with no signs of demyelination. The cranial nerve exam revealed abnormalities in 3 patients (facial neurography and/or blink reflex test). Three patients showed resolution of SNAP amplitude reduction in serial neurophysiological studies, suggesting the presence of reversible sensory nerve conduction block. Results from cranial MRI scans were normal in all patients. CONCLUSION An electrophysiological pattern of sensory axonal neuropathy, with no associated signs of demyelination, is an early finding of FBS. Early neurophysiological evaluation and follow-up are essential for diagnosing patients with FBS.
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Affiliation(s)
- M A Alberti
- Unidad de Neuromuscular, Servicio de Neurología, Hospital Universitario de Bellvitge-IDIBELL, L' Hospitalet de Llobregat, Barcelona, España
| | - M Povedano
- Unidad de Neuromuscular, Servicio de Neurología, Hospital Universitario de Bellvitge-IDIBELL, L' Hospitalet de Llobregat, Barcelona, España
| | - J Montero
- Unidad de Neuromuscular, Servicio de Neurología, Hospital Universitario de Bellvitge-IDIBELL, L' Hospitalet de Llobregat, Barcelona, España
| | - C Casasnovas
- Unidad de Neuromuscular, Servicio de Neurología, Hospital Universitario de Bellvitge-IDIBELL, L' Hospitalet de Llobregat, Barcelona, España.
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Ursino G, Alberti MA, Grandis M, Reni L, Pareyson D, Bellone E, Gemelli C, Sabatelli M, Pisciotta C, Luigetti M, Santoro L, Massollo L, Schenone A. Influence of comorbidities on the phenotype of patients affected by Charcot-Marie-Tooth neuropathy type 1A. Neuromuscul Disord 2013; 23:902-6. [PMID: 23891256 DOI: 10.1016/j.nmd.2013.07.002] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2013] [Revised: 06/17/2013] [Accepted: 07/02/2013] [Indexed: 11/29/2022]
Abstract
Charcot-Marie-Tooth type 1A (CMT1A) is the most common inherited neuropathy. The phenotype of patients affected by CMT1A is highly variable and may be influenced by several conditions. We evaluated how comorbidities such as diabetes, hypothyroidism, exposure to toxins and obesity can modify or exacerbate the clinical and neurophysiological phenotype of CMT1A patients. Disability was measured using the classic CMT neuropathy score. Compared to controls, all groups of CMT1A patients with comorbidities had higher CMT neuropathy score. In particular, patients with CMT1A and diabetes mellitus show motor subscores which are significantly higher than in control CMT1A. Amplitudes of ulnar CMAP are lower in patients with CMT1A and diabetes mellitus, but not at a significant level. As expected, motor nerve conduction velocity is not influenced by any of the comorbidities. The presence of concomitant diseases shows a tendency to worsen the clinical and neurophysiological CMT1A phenotype, especially in patients with CMT1A and diabetes mellitus, where higher values in the CMT neuropathy score and clinical motor subscore have been observed.
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Affiliation(s)
- Giulia Ursino
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetic and Maternal Infantile Sciences, University of Genoa, Italy
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