A clinical perspective on muscle specific kinase antibody positive myasthenia gravis

The discovery of autoantibodies directed against muscle-specific kinase (MuSK) in “seronegative” myasthenia gravis (MG) patients marked a milestone in MG research. In healthy muscle, MuSK regulates a phosphorylation pathway, which is essential for the development and maintenance of acetylcholine rec...

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Main Authors: Omar Keritam, Angela Vincent, Fritz Zimprich, Hakan Cetin
Format: Article
Language:English
Published: Frontiers Media S.A. 2024-12-01
Series:Frontiers in Immunology
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Online Access:https://www.frontiersin.org/articles/10.3389/fimmu.2024.1502480/full
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author Omar Keritam
Omar Keritam
Angela Vincent
Fritz Zimprich
Fritz Zimprich
Hakan Cetin
Hakan Cetin
author_facet Omar Keritam
Omar Keritam
Angela Vincent
Fritz Zimprich
Fritz Zimprich
Hakan Cetin
Hakan Cetin
author_sort Omar Keritam
collection DOAJ
description The discovery of autoantibodies directed against muscle-specific kinase (MuSK) in “seronegative” myasthenia gravis (MG) patients marked a milestone in MG research. In healthy muscle, MuSK regulates a phosphorylation pathway, which is essential for the development and maintenance of acetylcholine receptor (AChR) clusters at the neuromuscular junction. Autoantibodies directed against MuSK are predominantly of the IgG4 subclass, but there is increasing evidence that IgG1-3 could also contribute to the pathology underlying MuSK-MG. MuSK-IgG4 are monovalent and block the binding site for LRP4 on MuSK, thereby inhibiting the downstream phosphorylation pathway and compromising the formation of AChR clusters. Clinically, MuSK-MG is commonly associated with the predominant involvement of bulbar, facial, shoulder and neck muscles. Cholinesterase inhibitors should be avoided in MuSK-MG due to the risk of clinical impairment and cholinergic crisis. Corticosteroids and other non-steroidal immunosuppressants are less effective with the need for higher doses and prolonged treatment. Rituximab, by contrast, has been shown to be particularly effective and is now often used early in the disease course. Its use is associated with a significant improvement in the clinical outcome of MuSK-MG patients over time. This review aims to describe the pathophysiology underlying MuSK-MG and provide a comprehensive overview of the clinical features and therapeutic options.
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spelling doaj-art-52c1ca63120c45dda5b9d36536fcee5f2025-08-20T02:18:55ZengFrontiers Media S.A.Frontiers in Immunology1664-32242024-12-011510.3389/fimmu.2024.15024801502480A clinical perspective on muscle specific kinase antibody positive myasthenia gravisOmar Keritam0Omar Keritam1Angela Vincent2Fritz Zimprich3Fritz Zimprich4Hakan Cetin5Hakan Cetin6Department of Neurology, Medical University of Vienna, Vienna, AustriaComprehensive Center for Clinical Neurosciences & Mental Health, Medical University of Vienna, Vienna, AustriaNuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United KingdomDepartment of Neurology, Medical University of Vienna, Vienna, AustriaComprehensive Center for Clinical Neurosciences & Mental Health, Medical University of Vienna, Vienna, AustriaDepartment of Neurology, Medical University of Vienna, Vienna, AustriaComprehensive Center for Clinical Neurosciences & Mental Health, Medical University of Vienna, Vienna, AustriaThe discovery of autoantibodies directed against muscle-specific kinase (MuSK) in “seronegative” myasthenia gravis (MG) patients marked a milestone in MG research. In healthy muscle, MuSK regulates a phosphorylation pathway, which is essential for the development and maintenance of acetylcholine receptor (AChR) clusters at the neuromuscular junction. Autoantibodies directed against MuSK are predominantly of the IgG4 subclass, but there is increasing evidence that IgG1-3 could also contribute to the pathology underlying MuSK-MG. MuSK-IgG4 are monovalent and block the binding site for LRP4 on MuSK, thereby inhibiting the downstream phosphorylation pathway and compromising the formation of AChR clusters. Clinically, MuSK-MG is commonly associated with the predominant involvement of bulbar, facial, shoulder and neck muscles. Cholinesterase inhibitors should be avoided in MuSK-MG due to the risk of clinical impairment and cholinergic crisis. Corticosteroids and other non-steroidal immunosuppressants are less effective with the need for higher doses and prolonged treatment. Rituximab, by contrast, has been shown to be particularly effective and is now often used early in the disease course. Its use is associated with a significant improvement in the clinical outcome of MuSK-MG patients over time. This review aims to describe the pathophysiology underlying MuSK-MG and provide a comprehensive overview of the clinical features and therapeutic options.https://www.frontiersin.org/articles/10.3389/fimmu.2024.1502480/fullmuscle-specific kinasemyasthenia gravisMuSK-MGIgG4neuromuscular junctionautoimmune disorder
spellingShingle Omar Keritam
Omar Keritam
Angela Vincent
Fritz Zimprich
Fritz Zimprich
Hakan Cetin
Hakan Cetin
A clinical perspective on muscle specific kinase antibody positive myasthenia gravis
Frontiers in Immunology
muscle-specific kinase
myasthenia gravis
MuSK-MG
IgG4
neuromuscular junction
autoimmune disorder
title A clinical perspective on muscle specific kinase antibody positive myasthenia gravis
title_full A clinical perspective on muscle specific kinase antibody positive myasthenia gravis
title_fullStr A clinical perspective on muscle specific kinase antibody positive myasthenia gravis
title_full_unstemmed A clinical perspective on muscle specific kinase antibody positive myasthenia gravis
title_short A clinical perspective on muscle specific kinase antibody positive myasthenia gravis
title_sort clinical perspective on muscle specific kinase antibody positive myasthenia gravis
topic muscle-specific kinase
myasthenia gravis
MuSK-MG
IgG4
neuromuscular junction
autoimmune disorder
url https://www.frontiersin.org/articles/10.3389/fimmu.2024.1502480/full
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