Muscle & Nerve最新文献

{"title":"Global Challenges in Electrodiagnostic Medicine Education-We Can Do Better.","authors":"Chilvana Patel, Nortina Shahrizaila, Devon I Rubin","doi":"10.1002/mus.70347","DOIUrl":"10.1002/mus.70347","url":null,"abstract":"<p><p>Training in electrodiagnostic (EDX) medicine is highly variable globally, with trainees receiving widely different levels of didactic education, skills training, and hands-on experience. Global standardization of EDX training has the potential to improve diagnostic accuracy, promote equitable care, and strengthen international collaboration. Major barriers include limited resources, faculty shortages, and a lack of standardized curricula. To address these disparities, opportunities and strategies for international collaboration are proposed, including developing a uniform content curriculum, competency-based evaluation frameworks, and integration of online and simulation-based learning tools.</p>","PeriodicalId":18968,"journal":{"name":"Muscle & Nerve","volume":" ","pages":"553-558"},"PeriodicalIF":2.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13471884/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148471908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the Content Validity of Patient-Reported Outcome Measures to Capture the Patient Experience of Becker Muscular Dystrophy.","authors":"Abby Bronson, Katie Mellor, Nicole Kilburn, Ryan Fischer, Natalie Aldhouse, Chris Marshall, Tamara Al-Zubeidi","doi":"10.1002/mus.70302","DOIUrl":"10.1002/mus.70302","url":null,"abstract":"<p><strong>Introduction/aims: </strong>The patient experience of Becker muscular dystrophy (BMD) is not well understood, making it difficult to evaluate the conceptual relevance of proposed patient-reported outcome (PRO) measures. This study aimed to conceptualize the patient experience of BMD and evaluate content validity and perceptions of meaningful changes of PRO measures in this population.</p><p><strong>Methods: </strong>Semi-structured interviews were conducted with ambulatory adult and adolescent US-based participants with BMD. Transcripts were analyzed using content and framework analysis. Participant quotes were coded to identify concepts and themes, illustrated in a conceptual model of BMD experience. Cognitive debriefing methods assessed patient understanding of the brief pain inventory-short form (BPI-SF), quality of life in neurological disorders (Neuro-QoL), and three patient-reported outcomes measurement information system (PROMIS-57) domains: Physical Function, Fatigue, and Pain Interference.</p><p><strong>Results: </strong>Twenty-nine patients (mean age: 27.0 years; mean age at BMD diagnosis: 15.1 years) and two caregivers described a wide range of signs, symptoms, and impacts. Physical fatigue, pain, weakness, and impacts on physical mobility and emotional wellbeing were considered most bothersome. The BPI-SF Item 3 and PROMIS-57 domains were well understood and relevant; however, the Neuro-QoL Upper Extremity questionnaire demonstrated low conceptual relevance.</p><p><strong>Discussion: </strong>The conceptual model illustrated the burden of living with BMD. The BPI-SF Item 3 and evaluated PROMIS-57 domains are considered content-valid PRO measures in BMD, with most participants associating score improvements with meaningful changes to their health-related quality of life.</p>","PeriodicalId":18968,"journal":{"name":"Muscle & Nerve","volume":" ","pages":"559-569"},"PeriodicalIF":2.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13471961/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148271614","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Development and Validation of a Novel, Disease-Specific, Caregiver-Reported Outcome Measure: The Duchenne Muscular Dystrophy Caregiver Reported-Health Index (DMDCR-HI).","authors":"Charlotte Engebrecht, Spencer Rosero, Jennifer Weinstein, Jamison Seabury, Anika Varma, Christine Zizzi, John Heatwole, Nuran Dilek, Aaron Kaat, Debra Guntrum, Emma Ciafaloni, Chad Heatwole","doi":"10.1002/mus.70327","DOIUrl":"10.1002/mus.70327","url":null,"abstract":"<p><strong>Aim: </strong>Regulatory-grade outcome measures are essential for supporting future therapeutic trials. The goal of our study was to develop and validate a multifactorial, disease-specific, caregiver-reported outcome (CRO) measure for Duchenne muscular dystrophy (DMD).</p><p><strong>Methods: </strong>We conducted qualitative interviews and a cross-sectional study with caregivers of individuals with DMD to determine the most prevalent and impactful symptoms to individuals with DMD. Symptom items were selected for the Duchenne Muscular Dystrophy Caregiver Reported-Health Index (DMDCR-HI) based on their prevalence and impact to a national sample cohort of caregivers, along with their potential ability to respond to therapeutics. Subsequently, we conducted cognitive beta interviews, test-retest reliability assessments, and internal consistency analyses to evaluate and optimize the DMDCR-HI. Using known group analysis, we assessed the ability of the DMDCR-HI to differentiate between patients with differing levels of disease burden.</p><p><strong>Results: </strong>The DMDCR-HI is a regulatory-grade CRO that comprehensively measures 16 subscales in DMD. The instrument has a high internal consistency, strong test-retest reliability (intraclass correlation coefficient (ICC) = 0.96), and was identified by caregivers as easy to use, relevant, and comprehensive. Through known group analysis, DMDCR-HI scores demonstrated an ability to differentiate between subgroups with varying levels of symptomatic burden.</p><p><strong>Discussion: </strong>The DMDCR-HI is a valid and reliable CRO designed to sensitively and reliably capture how individuals with DMD feel and function from the perspective of the caregiver. The DMDCR-HI offers a robust mechanism to longitudinally track changes in disease burden in individuals with DMD, regardless of age, cognitive ability, or ambulation status.</p>","PeriodicalId":18968,"journal":{"name":"Muscle & Nerve","volume":" ","pages":"623-635"},"PeriodicalIF":2.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13472041/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148412492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"At-Home Versus in-Clinic Vital Capacity Measurement: Insights From the HEALEY ALS Platform Trial.","authors":"Eric A Macklin, James D Berry, Brittney A Harkey, Lindsay Heyd, Marianne Chase, Hong Yu, Alexander V Sherman, Derek Dagostino, Gale Kittle, Meghan Hall, Mariah R Connolly, Kristin Drake, Elisa Giacomelli, Erica Scirocco, Saloni Sharma, Suma Babu, Michael Benatar, Zachary Simmons, Eufrosina Young, Merit E Cudkowicz, Jeremy Shefner, Sabrina Paganoni","doi":"10.1002/mus.70322","DOIUrl":"10.1002/mus.70322","url":null,"abstract":"<p><strong>Introduction/aims: </strong>Respiratory weakness, typically monitored as vital capacity (VC), is a central feature of amyotrophic lateral sclerosis (ALS). VC is increasingly measured remotely in participants' homes, although in-clinic assessment remains the standard. We tested concordance between at-home and in-clinic VC to determine trial eligibility, track progression, and predict survival in a large ALS trial.</p><p><strong>Methods: </strong>At-home and in-clinic VC were assessed at baseline and approximately every 8 weeks for a year in the first four regimens of the HEALEY ALS Platform Trial. At-home assessments were coached via live videoconference and centrally reviewed. VC measurements, expressed as percent of predicted normal (%PN), were compared cross-sectionally, longitudinally, and for predicting survival time. Data from 233 participants with 3-8 paired at-home and in-clinic VC assessments completed < 14 days apart were analyzed.</p><p><strong>Results: </strong>At-home and in-clinic VC were well correlated (Lin's r _c  = 0.82) with no systematic bias. At-home VC ≥ 60%PN predicted in-clinic VC ≥ 60%PN with a positive predictive value of 91% and a negative predictive value of 65%. VC slopes were moderately correlated (r _c  = 0.68). At-home VC progressed 28% faster than in-clinic VC with proportionately less variance (at-home [SE] = -1.882 [0.153] %PN/month, in-clinic = -1.476 [0.131] %PN/month). Slopes of at-home and in-clinic VC explained 15% and 17% of variation in future survival time, respectively.</p><p><strong>Discussion: </strong>At-home and in-clinic VC were well correlated cross-sectionally. At-home VC performed well tracking longitudinal change and predicting survival. The reduced participant burden of assessment and concordance with in-clinic measurement support use of at-home monitoring of VC.</p>","PeriodicalId":18968,"journal":{"name":"Muscle & Nerve","volume":" ","pages":"702-708"},"PeriodicalIF":2.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13471965/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148346001","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Muscle-Specific Kinase Signaling and Its Therapeutic Potential.","authors":"Stine Marie Jensen, Dana L E Vergoossen, Maartje G Huijbers","doi":"10.1002/mus.70129","DOIUrl":"10.1002/mus.70129","url":null,"abstract":"<p><p>The function of the neuromuscular junction (NMJ) is compromised in many neuromuscular diseases (NMDs) such as autoimmune or congenital myasthenia gravis (MG), amyotrophic lateral sclerosis (ALS), spinal muscular atrophy (SMA), and muscular dystrophies. The NMJ contains muscle-specific kinase (MuSK), which is a critical regulator of NMJ integrity and function. Activating the MuSK signaling cascade may have therapeutic potential in several of these NMDs that are characterized by impaired neuromuscular communication. The MuSK signaling cascade consists of different components and can be activated with interventions at different levels. In the past years, different therapeutic strategies using an engineered recombinant agrin comprised of the C-terminal fragment of the protein (mini-agrin), gene therapy of key proteins in this pathway, agonist MuSK antibodies, and SRC homology 2 domain-containing phosphotyrosine phosphatase 2 (SHP2) inhibitors have been further developed for this purpose. Each of these strategies engages distinct signaling components: mini-agrin, both as recombinant protein and gene therapy, enhances agrin-Lrp4-MuSK interaction; Dok7 gene therapy amplifies MuSK phosphorylation; Lrp4 gene therapy enhances agrin responsiveness; MuSK agonist antibodies bypass upstream defects and promote downstream signaling; SHP2 inhibitors prolong the duration of active MuSK signaling. These therapeutic strategies have ameliorated NMJ integrity and function in several preclinical models of MG, motor neuron diseases, and muscular dystrophies. In this review, we highlight MuSK signaling as a possible therapeutic target, describe the therapeutic efficacy of intervention in MuSK signaling in different NMDs, and present an outlook on future clinical development.</p>","PeriodicalId":18968,"journal":{"name":"Muscle & Nerve","volume":" ","pages":"S65-S75"},"PeriodicalIF":2.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13599456/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148369440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Antibody-Microbiota Interface in Autoimmune Diseases.","authors":"Solène Puechberty, Delphine Sterlin","doi":"10.1002/mus.70131","DOIUrl":"10.1002/mus.70131","url":null,"abstract":"<p><p>The human intestine harbors a dense community of commensal microbes that strongly shape humoral immune responses. While secretory immunoglobulin A (sIgA) has long been recognized as a key regulator of microbiota compartmentalization and intestinal homeostasis, recent studies have also highlighted important roles for secretory IgM and systemic IgG in host-microbiota interactions. In this review, we examine critical aspects of the antibody-microbiota interface, first showing the extent to which microbiota and factors influencing microbiota ecosystem such as diet shape sIgA repertoire and binding capacity. We further integrate insights from both murine and human studies to provide a comprehensive overview of how antibody-microbiota interactions are altered in autoimmune diseases and contribute both to the identification of microbial drivers of disease and to the development of new therapeutic approaches. It is noteworthy that myasthenia gravis (MG) patients have a unique microbial signature, different from other autoimmune diseases, suggesting that yet-to-be-identified gut bacteria might specifically drive the host's immune response toward MG. Finally, we discuss the mechanisms through which the microbiota may contribute to the initiation or perpetuation of dysregulated immune responses underlying autoimmunity. Given the presence of IgA autoantibodies in MG patients and the broad homology between the acetylcholine receptor and the microbial proteome, molecular mimicry and epitope spreading should be investigated as potential triggering mechanisms.</p>","PeriodicalId":18968,"journal":{"name":"Muscle & Nerve","volume":" ","pages":"S7-S23"},"PeriodicalIF":2.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145945305","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Determinants of the Maximal Nerve Cross-Sectional Area and Its Role in the Separation of Entrapment and Compression Ulnar Neuropathies at the Elbow.","authors":"Simon Podnar","doi":"10.1002/mus.70324","DOIUrl":"10.1002/mus.70324","url":null,"abstract":"<p><strong>Introduction/aims: </strong>Nerve cross-sectional area (CSA) is the most robust and sensitive ultrasonographic indicator of nerve pathology. The study aimed to identify predictors of maximal CSA (CSA_max) in ulnar neuropathy at the elbow (UNE) and to assess its utility in elucidating the mechanism of UNE, which is potentially important for patient referral to a surgeon.</p><p><strong>Methods: </strong>In a group of prospectively recruited UNE patients, 11 demographic, clinical, and electrodiagnostic features were recorded. CSA_max in the elbow segment was measured ultrasonographically. Explanatory variables for CSA_max were determined using a backward stepwise method of multiple linear regression analysis. To determine the CSA_max threshold with the best differentiation of retrocondylar compression and cubital tunnel entrapment (i.e., the UNE mechanism), a ROC curve was constructed.</p><p><strong>Results: </strong>We studied 130 patients (94 men), aged 27-88 years (median 62 years). The only significant predictor of CSA_max was the mechanism of UNE (CSA_max = 7.49 + 6.89 UNE mechanism, SE 1.04, (adjusted) R ² = 0.25, p < 0.0001). The best differentiation between UNE mechanisms was obtained at the CSA_max of 16 mm² (sensitivity 0.80, positive predictive value 0.71).</p><p><strong>Discussion: </strong>In UNE, the main determinant of CSA_max was the mechanism of neuropathy. In the UNE of unclear mechanism, CSA_max larger than 16 mm² is more in favor of a cubital tunnel entrapment. These findings suggest that US is more sensitive in the diagnosis of entrapment compared with compression neuropathies.</p>","PeriodicalId":18968,"journal":{"name":"Muscle & Nerve","volume":" ","pages":"600-604"},"PeriodicalIF":2.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13471758/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148295592","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The Emotional Experiences of Healthcare Professionals Working in Amyotrophic Lateral Sclerosis: A Systematic Review.","authors":"Young Chan, Sarah Creer, Jess Mere, Alys Wyn Griffiths, Charlotte Wright, Esther V Hobson, Christopher J McDermott, Emily J Mayberry","doi":"10.1002/mus.70309","DOIUrl":"10.1002/mus.70309","url":null,"abstract":"<p><p>Healthcare professionals (HCPs) working with people living with amyotrophic lateral sclerosis (ALS) are often exposed to emotive circumstances including end of life care, trauma, loss, and death. Existing reviews have explored the emotional experiences of people living with ALS and their carers but have largely ignored healthcare staff and the impact of this work on them. This systematic review of qualitative research aims to explore the emotional experiences of and impact on HCPs working with people living with ALS using thematic synthesis (PROSPERO reference: CRD42025631749). Electronic databases were searched for journal articles and gray literature (Medline, Scopus, PsycINFO, Google Scholar, King's Fund Library Database, ProQuest Dissertations, Theses Global) for qualitative or mixed-methods studies exploring the emotional impact on HCPs working in ALS. Twelve studies were included, critically appraised, and analyzed. Four themes were identified. The emotional intensity due to the nature of ALS created challenges for HCPs, while they were also faced with absorbing the emotions of others. HCPs learned to balance their emotional involvement, and HCPs also described positive experiences and coping mechanisms. HCPs working in ALS experience multi-faceted emotional challenges, and they do describe positive emotional experiences within their roles. However, HCPs describe having few coping mechanisms and limited formal support systems in place to process the intense emotions or to guide their emotional involvement. The lack of support for staff may ultimately negatively affect patient care. There is an unmet demand for debriefing, supervision, and further training on how to deal with intense, distressing emotions.</p>","PeriodicalId":18968,"journal":{"name":"Muscle & Nerve","volume":" ","pages":"517-529"},"PeriodicalIF":2.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13471968/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148278007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"AGRN-, LRP4-, MUSK-Related CMS: Clinical, Neurophysiological, Morphological, Genetic and Pathological Mechanisms.","authors":"Rocio-Nur Villar-Quiles, Damien Sternberg, Marie-Christine Nougues, Arnaud Isapof, Bruno Eymard, Stéphanie Bauché","doi":"10.1002/mus.70081","DOIUrl":"10.1002/mus.70081","url":null,"abstract":"<p><p>Congenital myasthenic syndromes (CMS) are inherited disorders caused by mutations in genes encoding proteins essential for neuromuscular junction (NMJ) function. Pathogenic variants have been identified in more than 35 genes, underscoring the complexity of synaptic biology and the wide range of mechanisms that can compromise neuromuscular transmission. Among these, CMS due to mutations in AGRN, LRP4, and MUSK genes represent presynaptic and postsynaptic defects that offer valuable mechanistic insights. These mutations impair agrin/LRP4/MuSK signaling, disrupt NMJ formation and stability, and underlie phenotypes with variable clinical presentations, ranging from ptosis and fatigability to distal, bulbar, or respiratory weakness. These subtypes often show limited efficacy or even clinical worsening with acetylcholinesterase inhibitors, whereas adrenergic agonists such as salbutamol or ephedrine can provide significant benefit in selected cases. The study of these forms not only provides key insights into the molecular regulation of synapse development and maintenance, but also illustrates the challenges of establishing genotype-phenotype correlations in rare diseases, in which inter-individual variability complicates diagnosis and management. Recent advances in next-generation sequencing and functional studies have expanded the recognized mutation spectrum, uncovered novel pathogenic mechanisms, and improved the accuracy of molecular diagnosis. In this review, we provide a comprehensive overview of AGRN, LRP4, and MUSK-related CMS, integrating clinical, genetic, and mechanistic data from patients and experimental models. By highlighting diagnostic strategies, pathogenic pathways, and emerging therapeutic concepts, we show how these rare subtypes refine our understanding of NMJ biology and open the way toward personalized and mechanism-based treatments.</p>","PeriodicalId":18968,"journal":{"name":"Muscle & Nerve","volume":" ","pages":"S31-S40"},"PeriodicalIF":2.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13599455/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148361656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"IgG Subclass (IgG1-4) and IgA Autoantibody Profiles Against Muscle-Specific Kinase in a Greek Cohort.","authors":"Sofia-Natsοuko Gkotzamani, Maria Pechlivanidou, Francisca Faber, Cansu Elmas, Vasiliki Zouvelou, Elisabeth Chroni, Dimitrios Tzanetakos, Maria Kourouvani, Marlene Wolfsgruber, Ioannis Zaganas, Dimitra Kolovou, Michael Rentzos, Ariadne Daponte, Maria Chondrogiorgi, Spyridon Konitsiotis, Georgios Nicolaou, Stavroula Salakou, Sotirios Giannopoulos, Konstandinos Lazaridis, Georgios Tsivgoulis, Socrates Tzartos, Inga Koneczny, John S Tzartos","doi":"10.1002/mus.70284","DOIUrl":"10.1002/mus.70284","url":null,"abstract":"<p><strong>Introduction/aims: </strong>Muscle-specific kinase myasthenia gravis (MuSK-MG) is an autoimmune neuromuscular disorder predominantly mediated by IgG4 autoantibodies disrupting MuSK signaling. The contribution of other isotypes remains incompletely defined. We characterized the serological profile of a Greek cohort of MuSK-MG patients.</p><p><strong>Methods: </strong>Baseline (n = 140) and longitudinal (available n = 99) samples from 140 patients, positive for anti-MuSK by radioimmunoprecipitation (RIPA) were analyzed using a live cell-based assay (L-CBA) to detect total IgG, IgG1-4 subclasses, IgM, and IgA. Also, disease and healthy controls (n = 102) were included. Selected samples were additionally analyzed by flow cytometry. Clinical data were available for specific patients.</p><p><strong>Results: </strong>Our analysis revealed 15 distinct immunoglobulin combinations and provided insights into the presence of IgA isotype. IgG4 was the most common subclass in 120/140 of patients, followed by IgG1 in 79/140, IgG3 in 59/140, and IgG2 in 42/140 patients, while IgM positivity was detected in selected patients. Anti-MuSK IgA(1) immunoreactivity was detected in 54/140 patients, frequently co-occurring with IgG, and in four patients at baseline with only-IgA positivity. IgA was detected both near disease onset and at later stages, and persisted over time in rituximab-treated patients. Controls tested largely negative for IgA, although low-intensity signals were observed in six samples and were considered non-specific. L-CBA detected anti-MuSK IgA more frequently than flow cytometry.</p><p><strong>Discussion: </strong>Our findings expand the serology of MuSK-MG beyond IgG subclasses, identifying IgA as an additional component of the anti-MuSK response. These results enhance further investigation into the clinical significance, pathogenic potential, and treatment-associated fluctuations of anti-MuSK IgA antibodies.</p>","PeriodicalId":18968,"journal":{"name":"Muscle & Nerve","volume":" ","pages":"S132-S141"},"PeriodicalIF":2.9,"publicationDate":"2026-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13599460/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148352662","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}