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Huang EJC, Wu MH, Wang TJ, Huang TJ, Li YR, Lee CY. Myasthenia Gravis: Novel Findings and Perspectives on Traditional to Regenerative Therapeutic Interventions. Aging Dis 2023; 14:1070-1092. [PMID: 37163445 PMCID: PMC10389825 DOI: 10.14336/ad.2022.1215] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Accepted: 12/15/2022] [Indexed: 05/12/2023] Open
Abstract
The prevalence of myasthenia gravis (MG), an autoimmune disorder, is increasing among all subsets of the population leading to an elevated economic and social burden. The pathogenesis of MG is characterized by the synthesis of autoantibodies against the acetylcholine receptor (AChR), low-density lipoprotein receptor-related protein 4 (LRP4), or muscle-specific kinase at the neuromuscular junction, thereby leading to muscular weakness and fatigue. Based on clinical and laboratory examinations, the research is focused on distinguishing MG from other autoimmune, genetic diseases of neuromuscular transmission. Technological advancements in machine learning, a subset of artificial intelligence (AI) have been assistive in accurate diagnosis and management. Besides, addressing the clinical needs of MG patients is critical to improving quality of life (QoL) and satisfaction. Lifestyle changes including physical exercise and traditional Chinese medicine/herbs have also been shown to exert an ameliorative impact on MG progression. To achieve enhanced therapeutic efficacy, cholinesterase inhibitors, immunosuppressive drugs, and steroids in addition to plasma exchange therapy are widely recommended. Under surgical intervention, thymectomy is the only feasible alternative to removing thymoma to overcome thymoma-associated MG. Although these conventional and current therapeutic approaches are effective, the associated adverse events and surgical complexity limit their wide application. Moreover, Restivo et al. also, to increase survival and QoL, further recent developments revealed that antibody, gene, and regenerative therapies (such as stem cells and exosomes) are currently being investigated as a safer and more efficacious alternative. Considering these above-mentioned points, we have comprehensively reviewed the recent advances in pathological etiologies of MG including COVID-19, and its therapeutic management.
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Affiliation(s)
- Evelyn Jou-Chen Huang
- Department of Ophthalmology, Taipei Medical University Hospital, Taipei, Taiwan.
- Department of Ophthalmology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
| | - Meng-Huang Wu
- Department of Orthopedics, Taipei Medical University Hospital, Taipei, Taiwan.
- Department of Orthopaedics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
| | - Tsung-Jen Wang
- Department of Ophthalmology, Taipei Medical University Hospital, Taipei, Taiwan.
- Department of Ophthalmology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
| | - Tsung-Jen Huang
- Department of Orthopedics, Taipei Medical University Hospital, Taipei, Taiwan.
- Department of Orthopaedics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
| | - Yan-Rong Li
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Linkou Chang Gung Memorial Hospital and College of Medicine, Chang Gung University, Taoyuan, Taiwan.
| | - Ching-Yu Lee
- Department of Orthopedics, Taipei Medical University Hospital, Taipei, Taiwan.
- Department of Orthopaedics, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
- International PhD Program for Cell Therapy and Regeneration Medicine, College of Medicine, Taipei Medical University, Taipei 11031, Taiwan.
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Wang S, Breskovska I, Gandhy S, Punga AR, Guptill JT, Kaminski HJ. Advances in autoimmune myasthenia gravis management. Expert Rev Neurother 2018; 18:573-588. [PMID: 29932785 PMCID: PMC6289049 DOI: 10.1080/14737175.2018.1491310] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
INTRODUCTION Myasthenia gravis (MG) is an autoimmune neuromuscular disorder with no cure and conventional treatments limited by significant adverse effects and variable benefit. In the last decade, therapeutic development has expanded based on improved understanding of autoimmunity and financial incentives for drug development in rare disease. Clinical subtypes exist based on age, gender, thymic pathology, autoantibody profile, and other poorly defined factors, such as genetics, complicate development of specific therapies. Areas covered: Clinical presentation and pathology vary considerably among patients with some having weakness limited to the ocular muscles and others having profound generalized weakness leading to respiratory insufficiency. MG is an antibody-mediated disorder dependent on autoreactive B cells which require T-cell support. Treatments focus on elimination of circulating autoantibodies or inhibition of effector mechanisms by a broad spectrum of approaches from plasmapheresis to B-cell elimination to complement inhibition. Expert commentary: Standard therapies and those under development are disease modifying and not curative. As a rare disease, clinical trials are challenged in patient recruitment. The great interest in development of treatments specific for MG is welcome, but decisions will need to be made to focus on those that offer significant benefits to patients.
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Affiliation(s)
- Shuhui Wang
- Department of Neurology, George Washington University, Washington DC 20008
| | - Iva Breskovska
- Department of Neurology, George Washington University, Washington DC 20008
| | - Shreya Gandhy
- Department of Neurology, George Washington University, Washington DC 20008
| | - Anna Rostedt Punga
- Department of Neuroscience, Clinical Neurophysiology, Uppsala University, Uppsala, Sweden
| | - Jeffery T. Guptill
- Department of Neurology, Duke University Medical Center, Durham, North Carolina, USA
| | - Henry J. Kaminski
- Department of Neurology, George Washington University, Washington DC 20008
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MuSK autoantibodies in myasthenia gravis detected by cell based assay--A multinational study. J Neuroimmunol 2015; 284:10-7. [PMID: 26025053 DOI: 10.1016/j.jneuroim.2015.04.015] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 04/21/2015] [Accepted: 04/24/2015] [Indexed: 12/21/2022]
Abstract
Seronegative myasthenia gravis (MG) presents a serious gap in MG diagnosis and understanding. We applied a cell based assay (CBA) for the detection of muscle specific kinase (MuSK) antibodies undetectable by radioimmunoassay. We tested 633 triple-seronegative MG patients' sera from 13 countries, detecting 13% as positive. MuSK antibodies were found, at significantly lower frequencies, in 1.9% of healthy controls and 5.1% of other neuroimmune disease patients, including multiple sclerosis and neuromyelitis optica. The clinical data of the newly diagnosed MuSK-MG patients are presented. 27% of ocular seronegative patients were MuSK antibody positive. Moreover, 23% had thymic hyperplasia suggesting that thymic abnormalities are more common than believed.
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Sussman J, Argov Z, Wirguin Y, Apolski S, Milic-Rasic V, Soreq H. Further developments with antisense treatment for myasthenia gravis. Ann N Y Acad Sci 2013; 1275:13-6. [PMID: 23278572 DOI: 10.1111/j.1749-6632.2012.06825.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We present further developments in the study of the antisense oligonucleotide EN101. Ongoing in vitro and in vivo studies demonstrate that EN101 is a TLR9-specific ligand that can suppress pro-inflammatory functions and shift nuclear factor kappa B (NF-κB) from the pro-inflammatory canonical pathway to the anti-inflammatory alternative pathway, which results in decreases acetylcholinesterase (AChE) activity. Preliminary results of a double-blinded phase II cross-over study compared 10, 20, and 40 mg EN101 administered to patients with myasthenia gravis. Patients were randomly assigned to one of three treatment groups in weeks 1, 3, and 5 and received their pretreatment dose of pyridostigmine in weeks 2 and 4. Thus far, all doses show a decrease in QMG scores, with a greater response to higher doses.
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Affiliation(s)
- Jon Sussman
- Greater Manchester Neuroscience Centre, Manchester UK.
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Blotnick E, Hamra-Amitai Y, Wald C, Brenner T, Anglister L. Changes in acetylcholinesterase in experimental autoimmune myasthenia gravis and in response to treatment with a specific antisense. Eur J Neurosci 2012; 36:3077-85. [PMID: 22805122 DOI: 10.1111/j.1460-9568.2012.08218.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Controlled regulation of synaptic nicotinic acetylcholine receptors (AChRs) and acetylcholinesterase (AChE), together with maintenance of a dynamic balance between them, is a requirement for proper function of cholinergic synapses. In the present study we assessed whether pathological changes in AChR perturb this balance, and whether such changes can be corrected. We studied the influence of AChR loss, caused by experimental autoimmune myasthenia gravis (EAMG), on muscle AChE, as well as the reciprocal effect of an antisense targeted towards AChE on both AChR and AChE at the neuromuscular synapse. The extensor digitorum longus (EDL) muscles of EAMG Lewis rats were isolated, and AChE levels and isoform compositions were examined. Although AChE levels in the muscles of healthy and EAMG rats were similar, marked changes were observed in isoform composition. Healthy EDL muscles contained globular (G(1,2) , G(4) ) and asymmetric (primarily A(12) ) isoforms. G(1,2) -AChE was significantly reduced in EAMG muscles, whereas both G(4) - and A(12) -AChE remained unchanged. Treatment of EAMG rats with the antisense EN101 resulted in decreased total muscle AChE, with recovery in G(1,2) and reduction in A(12) -AChE. AChE/AChR ratios were determined at the neuromuscular junctions (NMJ). The decrease in AChR levels that occurred as the disease progressed resulted in a dramatic increase in this ratio, and a significant recovery towards normal ratios occurred after EN101 treatment. This improvement was primarily due to increased synaptic AChR content. Our findings emphasise the tight connection between AChR and AChE at the myasthenic NMJ, and the importance of the AChE/AChR ratio in maintaining the required cholinergic balance.
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Affiliation(s)
- Edna Blotnick
- Department of Medical Neurobiology, Institute for Medical Research, IMRIC, Hebrew University Medical School, Jerusalem, Israel
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Souroujon MC, Brenner T, Fuchs S. Development of novel therapies for MG: Studies in animal models. Autoimmunity 2010; 43:446-60. [DOI: 10.3109/08916930903518081] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Abstract
Myasthenia gravis (MG) is an autoimmune disorder usually caused by antibodies against either the acetylcholine receptor (AChR) or muscle-specific tyrosine kinase (MuSK) at the neuromuscular junction. Neuromuscular transmission failure results in muscle fatigue and weakness that can be treated symptomatically with acetylcholinesterase inhibitors (AChEIs). Long-term treatment with nonselective AChEIs may have considerable drawbacks; thus, this medication is ideally tapered when strength improves. Patients with AChR antibodies respond beneficially to treatment, whereas patients with MuSK antibodies generally do not. Recently, the selective AChEI EN101, which specifically targets the isoform of "read-through" AChE (AChE-R), has been developed and may be of importance for symptomatic relief in AChR-antibody seropositive MG. This article is a review of the mechanisms, therapeutic effects, and drawbacks, with both old and new AChEIs in MG.
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Affiliation(s)
- Anna Rostedt Punga
- Department of Clinical Neurophysiology, Uppsala University Hospital, 75185 Uppsala, Sweden.
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Sussman JD, Argov Z, McKee D, Hazum E, Brawer S, Soreq H. Antisense treatment for myasthenia gravis: experience with monarsen. Ann N Y Acad Sci 2008; 1132:283-90. [PMID: 18567879 DOI: 10.1196/annals.1405.022] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Acetylcholinesterase pre-mRNA is susceptible to alternative splicing. Myasthenia gravis has been shown to be associated with the expression of the readthrough transcript (AChE-R), which, unlike the normal "synaptic" transcript (AChE-S) is not tethered to the post-synaptic membrane, but is a soluble monomer in the synaptic cleft. In rats with experimental autoimmune myasthenia gravis (EAMG), inhibition of production of AChE-R using antisense is associated with a significant reduction in synaptic expression of AChE-R mRNA and protein, with improved muscle strength and stamina and increased survival. Synaptic AChE does not appear to be significantly affected by the induction of EAMG or treatment with antisense to AChE-R. Monarsen (EN101) is a synthetic 20-base antisense oligodeoxynucleotide directed against the human AChE gene. It is modified to achieve stability for oral administration. Sixteen patients with seropositive myasthenia gravis who were responsive to pyridostigmine were withdrawn from it and treated with Monarsen. Fourteen patients experienced a clinically significant response. In some, the improvement was dramatic. Although the dose of pyridostigmine was not optimized before the study, the majority of responders achieved better Quantitative Myasthenia Gravis scores than on pyridostigmine. The response of an individual muscle group to Monarsen was related to the degree of deterioration following the withdrawal of pyridostigmine. Cholinergic side effects were conspicuous by their absence. Monarsen is now being investigated in a phase II study.
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Affiliation(s)
- Jon D Sussman
- Department of Neurology, Greater Manchester Neuroscience Centre, Hope Hospital, Stott Lane, Salford, Greater Manchester. UK. M6 8HD.
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Brenner T, Nizri E, Irony-Tur-Sinai M, Hamra-Amitay Y, Wirguin I. Acetylcholinesterase inhibitors and cholinergic modulation in Myasthenia Gravis and neuroinflammation. J Neuroimmunol 2008; 201-202:121-7. [DOI: 10.1016/j.jneuroim.2008.05.022] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Revised: 05/27/2008] [Accepted: 05/28/2008] [Indexed: 10/21/2022]
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Fostieri E, Kostelidou K, Poulas K, Tzartos SJ. Recent advances in the understanding and therapy of myasthenia gravis. FUTURE NEUROLOGY 2006. [DOI: 10.2217/14796708.1.6.799] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Myasthenia gravis (MG) is a T-cell dependent autoimmune disease mediated by autoantibodies, which mainly target muscle nicotinic acetylcholine receptors (AChR) and cause loss of functional AChRs in the neuromuscular junction. Both MG and its major autoantigen are studied extensively, yet the etiology of the disease remains unclear, although it is known to be associated with the thymus. A genetic predisposition, combined with several unidentified environmental stimuli, likely creates a favorable milieu in which the disease can appear. Current research focusses on elucidating the cellular and molecular pathways of immune dysregulation, which underly MG outburst and progression. Considerable progress has been made concerning the involvement of the thymus, the identification of impaired mechanisms of immune control and the B–T-cell interaction in MG pathogenesis, while the role of chemokines arises as an intriguing new puzzle. Recent findings fueled the development of novel therapeutic approaches with some encouraging, although preliminary, results. This review summarizes recent achievements in the fields of both basic research and therapeutics.
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Affiliation(s)
- Efrosini Fostieri
- Hellenic Pasteur Institute, Department of Biochemistry, 127 Vas. Sofias Avenue, 11521 Athens, Greece
| | - Kalliopi Kostelidou
- Hellenic Pasteur Institute, Department of Biochemistry, 127 Vas. Sofias Avenue 11521 Athens, Greece
| | | | - Socrates J Tzartos
- Hellenic Pasteur Institute, Department of Biochemistry, 127 Vas. Sofias Avenue, 11521 Athens, Greece and, Department of Pharmacy, University of Patras, 26504 Patras, Greece
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