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Ramdas S, Painho T, Vanegas MI, Famili DT, Lim MJ, Jungbluth H. Targeted Treatments for Myasthenia Gravis in Children and Adolescents. Paediatr Drugs 2024:10.1007/s40272-024-00649-3. [PMID: 39198371 DOI: 10.1007/s40272-024-00649-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/04/2024] [Indexed: 09/01/2024]
Abstract
Myasthenia gravis (MG) is an antibody-mediated disorder of the neuromuscular junction affecting children and adults. MG is a treatable condition with most patients requiring immunosuppression for disease control and/or remission. Juvenile myasthenia gravis (JMG) is rare in comparison with adult-onset MG but given the same underlying pathophysiology, treatment strategies are similar to those in adults. Until recently, there were only a few randomised controlled trials (RCTs) for MG treatments in adults and none in children, and management strategies were primarily based on expert consensus. In addition, treatment options for refractory MG cases have been severely limited, resulting in poor long-term quality of life in such patients due to the significant disease burden. Recently, there have been several RCTs focussing on novel therapeutic strategies with potentially promising outcomes, suggesting a change in MG management over the coming years and access to more effective and faster-acting drugs for MG patients. This paper will review current and new MG treatments including efgartigimod, eculizumab, rozanolixizumab, ravulizumab, and zilucoplan, with a focus on juvenile myasthenia gravis.
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Affiliation(s)
- Sithara Ramdas
- Department of Paediatrics, MDUK Neuromuscular Centre, University of Oxford, Oxford, UK
- Department of Paediatric Neurology, John Radcliffe Hospital, Oxford, UK
| | - Teresa Painho
- Department of Paediatrics, MDUK Neuromuscular Centre, University of Oxford, Oxford, UK
- Neurology Unit, Hospital Dona Estefânia, Unidade Local de Saúde São José, Centro Clínico Académico de Lisboa, Lisbon, Portugal
| | - Maria I Vanegas
- Department of Paediatric Neurology, Evelina London Children's Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, Children's Neurosciences Centre, F02-Becket House, Lambeth Palace Road, London, SE1 7EU, UK
| | - Dennis T Famili
- Department of Paediatric Neurology, Evelina London Children's Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, Children's Neurosciences Centre, F02-Becket House, Lambeth Palace Road, London, SE1 7EU, UK
| | - Ming J Lim
- Department of Paediatric Neurology, Evelina London Children's Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, Children's Neurosciences Centre, F02-Becket House, Lambeth Palace Road, London, SE1 7EU, UK
- Women and Children's Health, Faculty of Life Sciences and Medicine (FoLSM), King's College London, London, UK
| | - Heinz Jungbluth
- Department of Paediatric Neurology, Evelina London Children's Hospital, Guy's & St. Thomas' Hospital NHS Foundation Trust, Children's Neurosciences Centre, F02-Becket House, Lambeth Palace Road, London, SE1 7EU, UK.
- Randall Centre for Cell and Molecular Biophysics, Muscle Signalling Section, Faculty of Life Sciences and Medicine (FoLSM), King's College London, London, UK.
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Jiang Z, Hu W, Ning Z, Wu L, Yang L, Liao H, Chen B, Tang J, Xu R, Guo F, Liu S. Serum globulin in children with myasthenia gravis: predicting relapse and prognosis. Neurol Res 2024; 46:669-678. [PMID: 38602312 DOI: 10.1080/01616412.2024.2340883] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 04/03/2024] [Indexed: 04/12/2024]
Abstract
OBJECTIVE Serum globulin is associated with inflammatory or immune disorders. However, it has not been established whether it is associated with myasthenia gravis (MG). We investigated the association between globulin with relapse and prognosis in children with MG. METHODS A cohort of 148 MG cases and 150 healthy children were retrospectively enrolled from January 2015 to December 2021. Multivariate logistic and Cox regression models were used to analyze the treatment outcomes and recurrence of case group, exploring the influence of globulin. RESULTS Compared with the control group, globulin levels in the MG group were slightly increased (t = 7.244, p < 0.001). After a mean follow-up of 2.25 ± 1.05 years, 35 cases relapsed, with a relapse rate of 23.65%. Logistic regression analysis showed that globulin levels at admission [adjusted odds ratio (OR) = 1.233, 95% confidence interval (CI) 1.028-1.472, p = 0.018] were independent risk factors for relapse. Cox regression analysis confirmed that globulin levels at admission affects relapse-free time [adjusted hazard ratio (HR) = 0.552, 95% CI 0.357-0.852, p = 0.007]. Receiver operating characteristic curve determined 25.10 as the optimal cutoff value for globulin. Cox regression showed that high globulin levels (>25.10) at admission (adjusted HR = 0.607, 95% CI 0.383-0.961, p = 0.033) were independent risk factors for poor therapeutic outcomes at follow-up. Ordinal logistic regression showed that globulin affects the treatment plan (OR = 1.445, 95% CI 1.223-1.847, p = 0.014). CONCLUSIONS Elevated globulin levels in children with MG on admission predicts a high relapse rate and poor long-term therapeutic efficacies.
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Affiliation(s)
- Zhi Jiang
- Department of Pediatrics, Jinan University First Affiliated Hospital, Guangzhou, China
- Department of Neurology, Hunan Children's Hospital, Changsha, China
| | - Wenjing Hu
- Department of Neurology, Hunan Children's Hospital, Changsha, China
| | - Zeshu Ning
- Department of Neurology, Hunan Children's Hospital, Changsha, China
| | - Liwen Wu
- Department of Neurology, Hunan Children's Hospital, Changsha, China
| | - Liming Yang
- Department of Neurology, Hunan Children's Hospital, Changsha, China
| | - Hongmei Liao
- Department of Neurology, Hunan Children's Hospital, Changsha, China
| | - Bo Chen
- Department of Neurology, Hunan Children's Hospital, Changsha, China
| | - Jingwen Tang
- Department of Neurology, Hunan Children's Hospital, Changsha, China
| | - Rong Xu
- Department of Neurology, Hunan Children's Hospital, Changsha, China
| | - Feng Guo
- Department of Neurology, Hunan Children's Hospital, Changsha, China
| | - Shulei Liu
- Department of Neurology, Hunan Children's Hospital, Changsha, China
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Rodrigues E, Umeh E, Aishwarya, Navaratnarajah N, Cole A, Moy K. Incidence and prevalence of myasthenia gravis in the United States: A claims-based analysis. Muscle Nerve 2024; 69:166-171. [PMID: 38040629 DOI: 10.1002/mus.28006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 11/03/2023] [Accepted: 11/11/2023] [Indexed: 12/03/2023]
Abstract
INTRODUCTION/AIMS Myasthenia gravis (MG) is a rare neuromuscular disorder with geographically variable prevalence and incidence rates. A global trend of increasing prevalence of MG has been observed in the last few decades, and this study aimed to assess the current prevalence and incidence rates of MG in the United States. METHODS Data were extracted from the Clarivate Real-World Data Repository (2016-2021), a US claims and electronic health records database. The prevalence and incidence of MG were calculated for the year 2021 for males and females who were <2, 2-5, 6-11, 12-17, 18-49, 50-64, and ≥65 years of age, using population estimates from the US Census. RESULTS The diagnosed prevalence and incidence of MG in the United States in 2021 were calculated to be 37.0 per 100,000 persons and 3.1 per 100,000 persons, respectively. While the incidence and prevalence of MG increased with age in both men and women, higher prevalence and incidence of MG were observed in younger women (<50 years) compared with men of matching age, and in older men (≥65 years) compared with women of the same age group. DISCUSSION The updated prevalence and incidence of MG in the United States in 2021 are higher than previous reports from the 1980s and early 2000s, following a global trend of increased prevalence and incidence for this disorder in the last few decades.
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Affiliation(s)
- Ema Rodrigues
- Alexion, AstraZeneca Rare Disease, Boston, Massachusetts, USA
| | - Emeka Umeh
- Clarivate Analytics, Boston, Massachusetts, USA
| | - Aishwarya
- Clarivate Analytics, Bangalore, Karnataka, India
| | | | - Alexander Cole
- Alexion, AstraZeneca Rare Disease, Boston, Massachusetts, USA
| | - Kristin Moy
- Alexion, AstraZeneca Rare Disease, Boston, Massachusetts, USA
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Hayashi M. Pathophysiology of Childhood-Onset Myasthenia: Abnormalities of Neuromuscular Junction and Autoimmunity and Its Background. PATHOPHYSIOLOGY 2023; 30:599-617. [PMID: 38133144 PMCID: PMC10747330 DOI: 10.3390/pathophysiology30040043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Revised: 11/28/2023] [Accepted: 11/29/2023] [Indexed: 12/23/2023] Open
Abstract
The pathophysiology of myasthenia gravis (MG) has been largely elucidated over the past half century, and treatment methods have advanced. However, the number of cases of childhood-onset MG is smaller than that of adult MG, and the treatment of childhood-onset MG has continued to be based on research in the adult field. Research on pathophysiology and treatment methods that account for the unique growth and development of children is now desired. According to an epidemiological survey conducted by the Ministry of Health, Labour and Welfare of Japan, the number of patients with MG by age of onset in Japan is high in early childhood. In recent years, MG has been reported from many countries around the world, but the pattern of the number of patients by age of onset differs between East Asia and Western Europe, confirming that the Japanese pattern is common in East Asia. Furthermore, there are racial differences in autoimmune MG and congenital myasthenic syndromes according to immunogenetic background, and their pathophysiology and relationships are gradually becoming clear. In addition, treatment options are also recognized in different regions of the world. In this review article, I will present recent findings focusing on the differences in pathophysiology.
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Affiliation(s)
- Masatoshi Hayashi
- Department of Pediatrics, Uwajima City Hospital, Uwajima 798-8510, Japan
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Gilhus NE. Myasthenia gravis, respiratory function, and respiratory tract disease. J Neurol 2023; 270:3329-3340. [PMID: 37101094 PMCID: PMC10132430 DOI: 10.1007/s00415-023-11733-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 04/14/2023] [Accepted: 04/16/2023] [Indexed: 04/28/2023]
Abstract
Myasthenia gravis (MG) is characterized by muscle weakness caused by autoantibodies that bind to the postsynaptic membrane at the neuromuscular junction and impair acetylcholine receptor function. Weakness of respiratory muscles represents the most severe MG manifestation, and 10-15% of all patients experience an MG crisis with the need of mechanical ventilatory support at least once in their life. MG patients with respiratory muscle weakness need active immunosuppressive drug treatment long term, and they need regular specialist follow-up. Comorbidities affecting respiratory function need attention and optimal treatment. Respiratory tract infections can lead to MG exacerbations and precipitate an MG crisis. Intravenous immunoglobulin and plasma exchange are the core treatments for severe MG exacerbations. High-dose corticosteroids, complement inhibitors, and FcRn blockers represent fast-acting treatments that are effective in most MG patients. Neonatal myasthenia is a transient condition with muscle weakness in the newborn caused by mother's muscle antibodies. In rare cases, treatment of respiratory muscle weakness in the baby is required.
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Affiliation(s)
- Nils Erik Gilhus
- Department of Neurology, Haukeland University Hospital, 5021, Bergen, Norway.
- Department of Clinical Medicine, University of Bergen, Bergen, Norway.
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Bi Z, Ge H, Zhang Q, Gao H, Yang M, Zhan J, Lin J, Gui M, Li Y, Ji S, Cao Y, Bu B. Clinical Features, Treatment, and Prognostic Factors of Childhood-Onset Myasthenia Gravis in a Large Chinese Cohort. Pediatr Neurol 2023; 146:31-39. [PMID: 37421800 DOI: 10.1016/j.pediatrneurol.2023.06.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/08/2023] [Accepted: 06/11/2023] [Indexed: 07/10/2023]
Abstract
BACKGROUND To describe the clinical features of patients with childhood-onset myasthenia gravis (MG) (CMG) and explore predictors affecting the treatment outcomes. METHODS A retrospective observational cohort analysis of 859 patients with CMG with disease onset before age 14 years was performed at Tongji Hospital. RESULTS Patients in the pubertal-onset group (n = 148) had a worse disease course than those in the prepubertal group (n = 711), including a higher incidence of generalized MG (GMG) at presentation, generalization of ocular MG (OMG), and more severe Myasthenia Gravis Foundation of America (MGFA) classification. All patients were initially treated with pyridostigmine, 657 with prednisone, and 196 with immunosuppressants (ISs). However, 226 patients were resistant to prednisone treatment. Multivariate analysis revealed that thymic hyperplasia, higher MGFA class, disease duration before prednisone administration, and thymectomy before prednisone administration were independent predictors of prednisone resistance. At the last visit, 121 of the 840 patients with OMG had developed GMG after a median of 10.0 years from symptom onset and 186 patients (21.7%) achieved complete stable remission (CSR). In multivariable analysis, age at onset, thymic hyperplasia, prednisone, and IS treatment were associated with generalization, whereas age at onset, disease duration, anti-acetylcholine receptor antibodies (AChR-ab), MGFA class II, short-term prednisone treatment, and IS treatment were associated with CSR. CONCLUSIONS The majority of patients with CMG have mild clinical symptoms and favorable outcomes, especially those with earlier onset age, shorter disease duration, and negative AChR-ab. In addition, early prednisone and ISs are shown to be effective and safe for most patients with CMG.
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Affiliation(s)
- Zhuajin Bi
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Huizhen Ge
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Qing Zhang
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Huajie Gao
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Mengge Yang
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Jiayang Zhan
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Jing Lin
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Mengcui Gui
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Yue Li
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Suqiong Ji
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Yayun Cao
- Department of Radiology, Zhongnan Hospital of Wuhan University, Wuhan, Hubei Province, China.
| | - Bitao Bu
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China.
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Lin Y, Kuang Q, Li H, Liang B, Lu J, Jiang Q, Yang X. Outcome and clinical features in juvenile myasthenia gravis: A systematic review and meta-analysis. Front Neurol 2023; 14:1119294. [PMID: 36970540 PMCID: PMC10032342 DOI: 10.3389/fneur.2023.1119294] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 02/17/2023] [Indexed: 03/10/2023] Open
Abstract
BackgroundJuvenile myasthenia gravis (JMG) is a rare autoimmune disease that has so far only been described in small cohort studies. We defined the clinical characteristics, management, and outcomes of JMG patients over the past 22 years.MethodsA search of PubMed, EMBASE, and web of science (1/2000–2/2022) identified all English language and human studies of JMG. The population was patients diagnosed with JMG. Outcomes included the history of myasthenic crisis, autoimmune comorbidity, mortality, and treatment outcome. Data extraction was performed by independent reviewers. And we performed a pooled reanalysis of all published data in the included studies and compared with other studies of adult cohorts.ResultsWe identified 11 articles describing 1,109 patients diagnosed between 2006 and 2021. JMG occurred in 60.4% of female patients. The mean age at presentation was 7.38 years old, and 60.6% of the patients had ocular symptoms as the first clinical manifestation. The most common initial presentation was ptosis, which occurred in 77.7% patients. AchR-Ab positive accounted for 78.7%. 641 patients received thymus examination, found to have thymic hyperplasia in 64.9% and thymoma in 2.2%. Autoimmune comorbidity was found in 13.6% and the most common one is thyroid disease (61.5%). First-line therapy, including pyridostigmine and steroids, was initiated in 97.8 and 68.6%, respectively. Six patients resolved spontaneously without treatment. Thymectomy was performed in 45.6%. 10.6% of patients had a history of myasthenic crisis. Completely stable remission was achieved in 23.7% and mortality was reported in 2 studies, which reported 8 deaths.ConclusionJMG is a rare disease with a relatively benign course, and differs from adult MG in some clinical features. The treatment regimen guideline for children is still not well-established. There is a need for prospective studies to properly evaluate treatment regimes.
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Tang YL, Ruan Z, Su Y, Guo RJ, Gao T, Liu Y, Li HH, Sun C, Li ZY, Chang T. Clinical Characteristics and Prognosis of Very late-onset Myasthenia Gravis in China. Neuromuscul Disord 2023; 33:358-366. [PMID: 36990040 DOI: 10.1016/j.nmd.2023.02.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Revised: 02/26/2023] [Accepted: 02/28/2023] [Indexed: 03/07/2023]
Abstract
Alteration in onset-age distribution in myasthenia gravis (MG) and its increasing prevalence among the elderly underscores the need for a better understanding of the clinical course of MG and the establishment of personalized treatment. In this study we reviewed the demographics, clinical profile, and treatment of MG. Based on onset age, eligible patients were classified as early-onset MG (onset age ≥18 and <50 years), late-onset MG (onset age ≥50 and <65 years), and very late-onset MG (onset age ≥65 years). Overall, 1160 eligible patients were enrolled. Patients with late- and very late-onset MG showed a male predominance (P=0.02), ocular MG subtype (P=0.001), and seropositivity for acetylcholine receptors and titin antibodies (P<0.001). In very late-onset MG, a lower proportion of patients retained minimal manifestations status or better, a higher proportion of patients had MG-related deaths (P<0.001), and a shorter maintenance time of minimal manifestation status or better was seen at the last follow-up (P=0.007) than that in patients with early- and late-onset MG. Non-immunotherapy may associated with a poor prognosis in patients in the very late-onset group. Further studies on very late-onset MG patients should be performed to evaluate the relationship between immunotherapy and prognosis.
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Affiliation(s)
- Yong-Lan Tang
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, China
| | - Zhe Ruan
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, China.
| | - Yue Su
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, China
| | - Rong-Jing Guo
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, China
| | - Ting Gao
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, China
| | - Yu Liu
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, China
| | - Huan-Huan Li
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, China
| | - Chao Sun
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, China
| | - Zhu-Yi Li
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, China.
| | - Ting Chang
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an 710038, China.
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Abstract
Myasthenia gravis is an autoimmune disorder caused by antibodies against elements in the postsynaptic membrane at the neuromuscular junction, which leads to muscle weakness. Congenital myasthenic syndromes are rare and caused by mutations affecting pre- or postsynaptic function at the neuromuscular synapse and resulting in muscle weakness. MG has a prevalence of 150-250 and an annual incidence of 8-10 individuals per million. The majority has disease onset after age 50 years. Juvenile MG with onset in early childhood is more common in East Asia. MG is subgrouped according to type of pathogenic autoantibodies, age of onset, thymus pathology, and generalization of muscle weakness. More than 80% have antibodies against the acetylcholine receptor. The remaining have antibodies against MuSK, LRP4, or postsynaptic membrane antigens not yet identified. A thymoma is present in 10% of MG patients, and more than one-third of thymoma patients develop MG as a paraneoplastic condition. Immunosuppressive drug therapy, thymectomy, and symptomatic drug therapy with acetylcholine esterase inhibitors represent cornerstones in the treatment. The prognosis is good, with the majority of patients having mild or moderate symptoms only. Most congenital myasthenic syndromes are due to dysfunction in the postsynaptic membrane. Symptom debut is in early life. Symptomatic drug treatment has sometimes a positive effect.
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Affiliation(s)
- Nils Erik Gilhus
- Department of Neurology, Haukeland University Hospital and Department of Clinical Medicine, University of Bergen, Bergen, Norway.
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Molimard A, Gitiaux C, Barnerias C, Audic F, Isapof A, Walther-Louvier U, Cances C, Espil-Taris C, Davion JB, Quijano-Roy S, Grisel C, Chabrol B, Desguerre I. Rituximab Therapy in the Treatment of Juvenile Myasthenia Gravis: The French Experience. Neurology 2022; 98:e2368-e2376. [PMID: 35314497 DOI: 10.1212/wnl.0000000000200288] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 02/10/2022] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE Corticosteroids are the first-line immunosuppressants in the management of juvenile myasthenia gravis despite their adverse effects. The place of new immunosuppressive therapies is not clearly defined by the last international consensus held in March 2019, due to the lack of clinical trials. The aim of this study is to describe the use of rituximab, its efficacy and safety in 8 main pediatric centers of the French neuromuscular reference network in order to propose a new place in the therapeutic strategy of juvenile myasthenia gravis. METHOD We conducted a retrospective multicenter study from January 1, 2009 to April 30, 2020, including a large cohort of children with myasthenia gravis in 8 main French pediatric reference centers of the Filnemus network. The type of myasthenia, the different lines of immunosuppressive treatment and the clinical course of the patients were collected. To evaluate the efficacy of rituximab, we studied the clinical course of patients on immunosuppressive therapy. Outcome was defined as the clinical and therapeutic status of patients at the last visit: stable without immunosuppressants, stable with immunosuppressants or unstable. RESULTS We included 74 patients: 18 children with ocular form and 56 children with generalized form. Of the 37 patients who required immunosuppressive therapy, 27 were treated with rituximab. Patients treated with rituximab had a better outcome than patients treated with conventional immunosuppressants (p = 0.006). The use of rituximab as a first-line immunosuppressant showed a better efficacy with a discontinuation of immunosuppressants in 75% of patients (vs. 25%, p=0.04) and resulted cortisone sparing (42% vs. 92%, p=0.03) compared with rituximab treatment as a second or third-line immunosuppression. Rituximab was well tolerated; no adverse effect was observed. CONCLUSION The use of rituximab has increased in France over the last 10 years as first line immunosuppressant. This study suggests a good tolerability and efficacy of rituximab in juvenile myasthenia gravis. Early use appears to improve outcomes and facilitate cortisone-sparing in antibody-positive generalized juvenile myasthenia. CLASSIFICATION OF EVIDENCE This study provides Class III evidence that for children with MG rituximab is effective and well tolerated.
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Affiliation(s)
| | - Cyril Gitiaux
- Centre de Référence des Maladies Neuromusculaires Nord/Ile de France/Est, Service de Neurologie pédiatrique, Hôpital Necker-Enfants Malades, APHP, Paris, France
| | - Christine Barnerias
- Centre de Référence des Maladies Neuromusculaires Nord/Ile de France/Est, Service de Neurologie pédiatrique, Hôpital Necker-Enfants Malades, APHP, Paris, France
| | - Frédérique Audic
- Centre de Référence des Maladies Neuromusculaires de l'enfant PACARARE, Service de Neuropédiatrie, Hôpital Timone Enfants, 264 rue Saint Pierre, 13385, Marseille Cedex 5
| | - Arnaud Isapof
- Centre de Référence des Maladies Neuromusculaires Nord/Ile de France/Est, Service de Neuropédiatrie, Hôpital Trousseau, APHP, Paris, France
| | - Ulrike Walther-Louvier
- Centre de Référence des Maladies Neuromusculaires AOC, Service de Neuropédiatrie CHU Montpellier, Montpellier, France
| | - Claude Cances
- Centre de Référence des Maladies Neuromusculaires AOC, Unité de Neurologie Pédiatrique, Hôpital des Enfants CHU Toulouse, Toulouse, France
| | - Caroline Espil-Taris
- Centre de Référence des Maladies Neuromusculaires AOC, Unité de Neurologie pédiatrique, CHU Pellegrin, Bordeaux, France
| | - Jean-Baptiste Davion
- Centre de référence des maladies neuromusculaires Nord Est Ile de France, CHU de Lille, Lille, France
| | - Susana Quijano-Roy
- Centre de Référence des Maladies Neuromusculaires Nord/Ile de France/Est, Hôpital Raymond Poincaré, APHP, Garches, France
| | - Coraline Grisel
- Service de pédiatrie, Centre Hospitalier Intercommunal de Créteil, Créteil, France
| | - Brigitte Chabrol
- Centre de Référence des Maladies Neuromusculaires de l'enfant PACARARE, Service de Neuropédiatrie, Hôpital Timone Enfants, 264 rue Saint Pierre, 13385, Marseille Cedex 5
| | - Isabelle Desguerre
- Centre de Référence des Maladies Neuromusculaires Nord/Ile de France/Est, Service de Neurologie pédiatrique, Hôpital Necker-Enfants Malades, APHP, Paris, France
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Heckmann JM, Europa TA, Soni AJ, Nel M. The Epidemiology and Phenotypes of Ocular Manifestations in Childhood and Juvenile Myasthenia Gravis: A Review. Front Neurol 2022; 13:834212. [PMID: 35280301 PMCID: PMC8904732 DOI: 10.3389/fneur.2022.834212] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Accepted: 01/24/2022] [Indexed: 11/28/2022] Open
Abstract
Myasthenia gravis (MG) appears to have a similar incidence among adult populations worldwide. However, epidemiological and phenotypic differences have been noted among children and juveniles with MG. We reviewed the literature on childhood- and juvenile-onset MG among different populations, with the focus on ocular involvement, antibody profiles, the genetic susceptibility to juvenile MG phenotypes, the use of immune treatments, and the reported responses of extraocular muscles to therapies. Although epidemiological studies used different methodologies, reports from Asia, compared to Europe, showed more than two-fold higher proportions of prepubertal onset (before 12 years) vs. postpubertal-onset juveniles with MG. Compared to European children, ocular MG was 4-fold more frequent among Asian children, and 2–3-fold more frequent among children with African ancestry both in prepubertal and postpubertal ages at onset. These results suggest genetic influences. In Asia, HLA-B*46 and DRB1*09 appeared overrepresented in children with ocular MG. In Europe, children with MG had a significantly higher rate of transforming from ocular to generalized disease and with an overrepresentation of HLADRB1*04. Although treatment regimens vary widely and the responses to immune therapies of the ocular muscles involved in MG were generally poorly described, there were indications that earlier use of steroid therapy may have better outcomes. Reports of treatment-resistant ophthalmoplegia may be more frequent in African and Asian juvenile MG cohorts compared to Europeans. Genetic and muscle gene expression studies point to dysregulated muscle atrophy signaling and mitochondrial metabolism pathways as pathogenetic mechanisms underpinning treatment-resistant ophthalmoplegia in susceptible individuals. In conclusion, phenotypic differences in juveniles with ocular manifestations of MG were evident in different populations suggesting pathogenetic influences. Treatment responses in MG-associated ocular disease should attract more careful descriptive reports. In MG, extraocular muscles may be vulnerable to critical periods of poor force generation and certain individuals may be particularly susceptible to developing treatment-resistant ophthalmoplegia. The development of prognostic biomarkers to identify these susceptible individuals is an unmet need.
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Affiliation(s)
- Jeannine M Heckmann
- Division of Neurology, Department of Medicine, University of Cape Town, Cape Town, South Africa.,Neurology Research Group, University of Cape Town (UCT) Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Tarin A Europa
- Division of Neurology, Department of Medicine, University of Cape Town, Cape Town, South Africa.,Neurology Research Group, University of Cape Town (UCT) Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Aayesha J Soni
- Division of Neurology, Department of Medicine, University of Cape Town, Cape Town, South Africa
| | - Melissa Nel
- Neurology Research Group, University of Cape Town (UCT) Neuroscience Institute, University of Cape Town, Cape Town, South Africa
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12
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Spontaneous Remission in Juvenile Myasthenia Gravis: A cohort of 13 cases and review of the literature. Neuromuscul Disord 2022; 32:213-219. [DOI: 10.1016/j.nmd.2021.11.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 11/28/2021] [Accepted: 11/29/2021] [Indexed: 11/30/2022]
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13
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Yang L, Tang Y, He F, Zhang C, Kessi M, Peng J, Yin F. Clinical characteristics and outcome predictors of a Chinese childhood-onset myasthenia gravis cohort. Front Pediatr 2022; 10:996213. [PMID: 36245736 PMCID: PMC9557758 DOI: 10.3389/fped.2022.996213] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Accepted: 09/15/2022] [Indexed: 11/13/2022] Open
Abstract
Myasthenia gravis is an organ-specific autoimmune disease. Currently there is no universal guidelines for childhood-onset myasthenia gravis, therefore, treatment strategies are usually based on the guidelines from adult myasthenia gravis patients. In order to contribute in the process of the development of the universal childhood-onset myasthenia gravis guideline, we have summarized the clinical characteristics, treatment strategies, outcome and the related predictors of childhood-onset myasthenia gravis. We recruited 343 childhood-onset myasthenia gravis cases who were followed up at the Department of Pediatrics, Xiangya Hospital from June, 2010 to December, 2019. The data about clinical characteristics, treatments and outcome were collected and analyzed. Among of the 343 cases, 164 cases were followed up for longer than 2 years, of whom 142 still remained with ocular myasthenia gravis at the endpoint. About the treatments, 27 cases (27/164) accepted pyridostigmine only while the rest accepted glucocorticoid and/or other immunosuppressants. At the endpoint, the proportion of optimal outcome was 66.2% in the group remaining with ocular myasthenia gravis and 31.8% in the generalized myasthenia gravis group. Multivariate logistic regression analysis revealed that generalized myasthenia gravis type and positive status of antibodies against acetylcholine receptors were the independent risk factors for poor outcome. In conclusion, our childhood-onset myasthenia gravis patients present mainly as ocular myasthenia gravis, adequate immunotherapy improve the long-term outcome, and generalized myasthenia gravis phenotype as well as positive status of antibodies against acetylcholine receptors relate to poor outcome.
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Affiliation(s)
- Lifen Yang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Yulin Tang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Fang He
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Ciliu Zhang
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Miriam Kessi
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital, Central South University, Changsha, China
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14
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Guo RJ, Gao T, Ruan Z, Zhou HY, Gao F, Xu Q, Yu LP, Wu SD, Lei T, Li HH, Sun C, Zhang M, Gao YW, Lu XD, Tang YL, Tang BL, Huo FY, Zhu Y, Li ZY, Chang T. Risk Factors for Generalization in Patients with Ocular Myasthenia Gravis: A Multicenter Retrospective Cohort Study. Neurol Ther 2021; 11:73-86. [PMID: 34729706 PMCID: PMC8857387 DOI: 10.1007/s40120-021-00292-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Accepted: 10/14/2021] [Indexed: 02/08/2023] Open
Abstract
Introduction Many patients with ocular myasthenia gravis (OMG) progress to generalized disease within the first 2 years of the onset of ocular symptoms. Several retrospective studies have identified risk factors associated with generalization, however these studies included patients on immunosuppression therapy or those undergoing thymectomy, which may reduce the generalization risk. In this study we explored the risk factors for generalization in non-immunosuppressed and non-thymectomized patients with OMG. Methods Data from patients with OMG treated at seven tertiary hospitals in China were retrospectively reviewed. Clinical characteristics, including sex, age at onset, symptoms at onset, comorbid autoimmune diseases, neostigmine test response, repetitive nerve stimulation (RNS) findings, presence of serum anti-acetylcholine receptor antibody (AChR-Ab), and thymic status based on radiological and pathological studies, were collected. The main outcome measure was disease generalization. The follow-up period was defined as the date of ocular symptom onset to the date of confirmation of generalization or immunotherapy initiation, or last follow-up (defined as 60 months). The Cox proportional hazards model was used to assess the risk factors for generalization. Results Overall, 572 patients (269 women) were eligible for inclusion in the analysis, of whom 144 developed generalization. The mean (standard deviation) onset age was 45.5 (19.8) years, and the median (interquartile range) follow-up period was 14.5 (7.0–47.3) months. Multivariable Cox regression analysis demonstrated that both early-onset (adjusted hazard ratio [aHR] 5.34; 95% confidence interval [CI] 1.64–17.36; p = 0.005) and late-onset (aHR 7.18; 95% CI 2.22–23.27; p = 0.001) in adulthood, abnormal RNS findings (aHR 3.01; 95% CI 1.97–4.61; p < 0.001), seropositivity for AChR-Ab (aHR 2.58; 95% CI 1.26–5.26; p = 0.01), and thymoma (aHR 1.62; 95% CI 1.05–2.49; p = 0.03) were independently associated with increased risk of generalization. Conclusion The risk of generalization increased significantly in patients with adult-onset OMG, abnormal RNS findings, seropositivity for AChR-Ab, and thymoma, suggesting that these risk factors may predict OMG generalization. Supplementary Information The online version contains supplementary material available at 10.1007/s40120-021-00292-x.
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Affiliation(s)
- Rong-Jing Guo
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China
| | - Ting Gao
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China
| | - Zhe Ruan
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China
| | - Hong-Yu Zhou
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
| | - Feng Gao
- Department of Neuroimmunology, Henan Institute of Medical and Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, China
| | - Quan Xu
- Department of Thoracic Surgery, Jiangxi Provincial People's Hospital, Nanchang, China
| | - Li-Ping Yu
- Department of Neurology, Xianyang First People's Hospital, Xianyang, China
| | - Song-Di Wu
- Department of Neurology, Xi'an No.1 Hospital, Xi'an, China
| | - Tao Lei
- Department of Neurology, Xi'an Fourth Hospital, Xi'an, China
| | - Huan-Huan Li
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China
| | - Chao Sun
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China
| | - Min Zhang
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China
| | - Yan-Wu Gao
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China
| | - Xiao-Dan Lu
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China
| | - Yong-Lan Tang
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China
| | - Bao-Li Tang
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China
| | - Fei-Yan Huo
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China
| | - Ying Zhu
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China
| | - Zhu-Yi Li
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.
| | - Ting Chang
- Department of Neurology, Tangdu Hospital, The Fourth Military Medical University, Xi'an, 710038, China.
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15
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Fc-Receptor Targeted Therapies for the Treatment of Myasthenia gravis. Int J Mol Sci 2021; 22:ijms22115755. [PMID: 34071155 PMCID: PMC8198115 DOI: 10.3390/ijms22115755] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 05/24/2021] [Accepted: 05/25/2021] [Indexed: 12/16/2022] Open
Abstract
Myasthenia gravis (MG) is an autoimmune disease in which immunoglobulin G (IgG) antibodies (Abs) bind to acetylcholine receptors (AChR) or to functionally related molecules in the postsynaptic membrane at the neuromuscular junction. IgG crystallizable fragment (Fc)-mediated effector functions, such as antibody-dependent complement deposition, contribute to disease development and progression. Despite progress in understanding Ab-mediated disease mechanisms, immunotherapy of MG remained rather unspecific with corticosteroids and maintenance with immunosuppressants as first choice drugs for most patients. More specific therapeutic IgG Fc-based platforms that reduce serum half-life or effector functions of pathogenic MG-related Abs are currently being developed, tested in clinical trials or have recently been successfully translated into the clinic. In this review, we illustrate mechanisms of action and clinical efficacies of emerging Fc-mediated therapeutics such as neonatal Fc receptor (FcRn)-targeting agents. Furthermore, we evaluate prospects of therapies targeting classical Fc receptors that have shown promising therapeutic efficacy in other antibody-mediated conditions. Increased availability of Fc- and Fc receptor-targeting biologics might foster the development of personalized immunotherapies with the potential to induce sustained disease remission in patients with MG.
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16
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Popperud TH, Gul KA, Brunborg C, Olaussen RW, Abrahamsen TG, Osnes LT, Kerty E. Thymectomy in Juvenile Myasthenia Gravis Is Safe Regarding Long Term Immunological Effects. Front Neurol 2021; 12:596859. [PMID: 33716918 PMCID: PMC7947605 DOI: 10.3389/fneur.2021.596859] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 01/29/2021] [Indexed: 11/13/2022] Open
Abstract
Thymectomy is an established treatment in adult MG and also recommended for the treatment of post-pubertal onset juvenile MG. Whether the youngest children should be thymectomized is still debated. Signs of premature aging of the immune system have been shown in studies on early perioperative thymectomy in children with congenital heart defect. In this retrospective cohort study the objective was to investigate the long-term effects of treatment related thymectomy on T cell subsets and T cell receptor rearrangement excision circles (TRECs) in peripheral blood of juvenile myasthenia gravis (MG) patients, as well as clinical occurrence of autoimmune disorders, malignancies and infectious diseases. Forty-seven patients with onset of myasthenia gravis before the age of 19 years were included; 32 (68.1%) had been thymectomized and 15 (31.8%) had not. They were studied at varying times after thymectomy (7–26 years). We found a significant lower number of naïve helper T cells (CD4+CD45RA+) with an increased proportion of memory helper T cells (CD4+CD45RO+), and a significant lower number of naïve cytotoxic T cells (CD8+CD27+CD28+) in the thymectomized patients. In addition they showed a significant reduction in the number of TRECs and proportion of recent thymic emigrants (RTE) compared to non-thymectomized patients. In none of them an increased frequency of malignancies or infections was found. Our findings indicate a premature aging of the immune system after thymectomy in juvenile MG, but associated clinical consequences could not be verified.
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Affiliation(s)
- Trine H Popperud
- Department of Neurology, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Kiran A Gul
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway.,Pediatric Research Institute, Oslo University Hospital, Oslo, Norway
| | - Cathrine Brunborg
- Oslo Centre for Biostatistics and Epidemiology, Research Support Services, Oslo University Hospital, Oslo, Norway
| | | | - Tore G Abrahamsen
- Division of Pediatric and Adolescent Medicine, Centre for Rare Disorders, Oslo University Hospital, Oslo, Norway
| | - Liv T Osnes
- Department of Immunology, Oslo University Hospital, Oslo, Norway
| | - Emila Kerty
- Department of Neurology, Oslo University Hospital, Oslo, Norway.,Institute of Clinical Medicine, University of Oslo, Oslo, Norway
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17
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Outcomes of Juvenile Myasthenia Gravis: A Comparison of Robotic Thymectomy With Medication Treatment. Ann Thorac Surg 2021; 113:295-301. [PMID: 33482164 DOI: 10.1016/j.athoracsur.2020.12.045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 09/20/2020] [Accepted: 12/30/2020] [Indexed: 11/23/2022]
Abstract
BACKGROUND The study aimed to compare the clinical outcomes of patients with juvenile myasthenia gravis (MG) who underwent robotic thymectomy with that of those who only received medication therapy. METHODS We retrospectively reviewed patients who visited our institution for the diagnosis or treatment of MG with an age at onset younger than 18 years. Patients who underwent thymectomy comprised the surgical group and those who received only medication therapy comprised the nonsurgical group. The clinical outcomes were assessed according to the Myasthenia Gravis Foundation of America Post-Intervention Status. RESULTS Forty-seven patients (35 female, 12 male) were included as the surgical group and 20 patients (15 female, 5 male) comprised the nonsurgical group. Significant differences were observed between the surgical and nonsurgical groups in antibody against acetylcholinesterase receptor (91.5% vs 65%; P = .012), disease duration (median 16 [interquartile range, 7-25] months vs 96 [interquartile range, 42-480] months; P < .001), and corticosteroids requirement (53.2% vs 15%; P = .004) at baseline. Kaplan-Meier analysis showed a higher cumulative probability of complete stable remission in the surgical group (P = .002) compared with the nonsurgical group. Moreover, thymectomy (hazard ratio, 3.842; 95% confidence interval, 1.116-13.230; P = .033) and age at onset (hazard ratio, 0.89; 95% confidence interval, 0.80-0.99; P = .037) were still associated with the achievement of complete stable remission in the multivariable analysis. Furthermore, a significant steroid-sparing effect was observed in the surgical group but not in the nonsurgical group. CONCLUSIONS Robotic thymectomy seems to be more effective than medication therapy on juvenile MG in terms of inducing remission and reducing the use of corticosteroids.
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18
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Zingariello CD, Elder ME, Kang PB. Rituximab as Adjunct Maintenance Therapy for Refractory Juvenile Myasthenia Gravis. Pediatr Neurol 2020; 111:40-43. [PMID: 32951658 DOI: 10.1016/j.pediatrneurol.2020.07.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/30/2020] [Accepted: 07/01/2020] [Indexed: 11/24/2022]
Abstract
BACKGROUND Juvenile myasthenia gravis is a pediatric autoimmune disorder of the neuromuscular junction associated with substantial morbidity, for which standard therapies are not always efficacious. The objective of our study was to assess the tolerability and efficacy of rituximab use in children with refractory juvenile myasthenia gravis. METHODS We conduced a retrospective cohort study at a single tertiary care referral center to evaluate children with juvenile myasthenia gravis who were treated with rituximab. The clinical status of these participants before and after initiation of rituximab therapy was measured, focusing on numbers of hospital admissions, numbers of immunomodulatory or immunosuppressive medications needed, and Myasthenia Gravis Foundation of America severity class. RESULTS Five children with juvenile myasthenia gravis were ascertained who received rituximab as part of their regimen, four of whom had elevated acetylcholine receptor antibodies and one of whom had elevated muscle-specific kinase antibodies. After initiation of rituximab therapy, all participants experienced reduced numbers of immunomodulatory medications during the follow-up period (mean 11.6 months). Four of the five subjects experienced fewer juvenile myasthenia gravis-related hospital admissions and reduced (improved) Myasthenia Gravis Foundation of America classes, with no subjects having moderate or severe symptoms following treatment with rituximab. No significant adverse events were recorded for any of the participants. CONCLUSION Rituximab was well-tolerated and efficacious in this juvenile myasthenia gravis cohort. The beneficial effect of rituximab was most pronounced in the one participant with muscle-specific kinase antibodies.
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Affiliation(s)
- Carla D Zingariello
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Melissa E Elder
- Division of Allergy, Immunology, and Rheumatology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida
| | - Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, Florida; Department of Neurology and Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, Florida.
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19
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Yan C, Zhao R, Song J, Feng X, Xi J, Luo S, Zhong H, Zhou S, Li W, Zhao C. Comparison of anti-acetylcholine receptor profiles between Chinese cases of adult- and juvenile-onset myasthenia gravis using cell-based assays. J Neuroimmunol 2020; 349:577403. [PMID: 32992216 DOI: 10.1016/j.jneuroim.2020.577403] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/29/2020] [Accepted: 09/19/2020] [Indexed: 10/23/2022]
Abstract
OBJECTIVE Juvenile-onset myasthenia gravis (JOMG) is a unique clinical subtype in China, featured by a higher prevalence of ocular myasthenia gravis (OMG), higher seronegativity of acetylcholine receptor (AChR) antibodies, and better prognosis than that in adult-onset myasthenia gravis (AOMG). We previously identified low-affinity AChR antibodies in Chinese JOMG patients using cell-based assays (CBAs), indicating a predominantly AChR antibody-positive profile. Here, we further screened AChR antibodies in both Chinese AOMG and JOMG patients by CBAs. MATERIALS AND METHODS We recruited patients with MG who had not received prednisone or immunosuppressive therapies between June 2015 and June 2019, and divided them into AOMG and JOMG subgroups according to their ages at the time of recruitment. Clinical information and blood samples were collected. Serum AChR antibodies were detected by CBAs in HEK293T cells expressing clustered adult and fetal AChRs, as well as by enzyme-linked immunosorbent assays (ELISAs). Differences in AChR antibody profiles between AOMG and JOMG subgroups were determined. RESULTS A total of 239 patients with MG were enrolled in the present study, including 121 AOMG and 118 JOMG patients. Based on ELISAs, 74.4% of AOMG (90/121) and 59.3% of JOMG (70/118) patients were anti-AChR positive (p = 0.02). However, CBAs yielded equal anti-AChR positivities (p = 0.64), as indicated by 80.2% of AOMG patients (97/121) and 77.1% of JOMG patients (91/118). Furthermore, among AOMG patients, 67.8% (82/121) were positive for both adult and fetal AChR antibodies, 5.8% (7/121) were positive for only adult AChR antibodies, and 6.6% (8/121) were positive for only fetal AChR antibodies, while these rates were 50.8% (60/118), 21.2% (25/118), and 5.1% (6/118), respectively, in JOMG cohorts (p < 0.01). Twenty-nine AOMG patients and 10 JOMG patients underwent IgG subclassification of AChR antibodies, which were all confirmed to be predominantly IgG1. CONCLUSIONS The positive rates of AChR antibodies did not differ between Chinese AOMG and JOMG patients, as revealed by CBAs. Furthermore, the screened AChR antibodies were predominantly IgG1 in both AOMG and JOMG patients.
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Affiliation(s)
- Chong Yan
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Rui Zhao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Jie Song
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Xuelin Feng
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangdong 510080, China
| | - Jianying Xi
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Sushan Luo
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Huahua Zhong
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Shuizhen Zhou
- Department of Neurology, Children's Hospital of Fudan University, Shanghai 200040, China
| | - Wenhui Li
- Department of Neurology, Children's Hospital of Fudan University, Shanghai 200040, China.
| | - Chongbo Zhao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China; Department of Neurology, Jing'an District Center Hospital of Shanghai, Fudan University, Shanghai 200040, China.
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20
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O'Connell K, Ramdas S, Palace J. Management of Juvenile Myasthenia Gravis. Front Neurol 2020; 11:743. [PMID: 32793107 PMCID: PMC7393473 DOI: 10.3389/fneur.2020.00743] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 06/16/2020] [Indexed: 02/06/2023] Open
Abstract
Juvenile Myasthenia Gravis (JMG) is a rare disorder, defined as myasthenia gravis in children younger than 18 years of age. While clinical phenotypes are similar to adults, there are a number of caveats that influence management: broader differential diagnoses; higher rates of spontaneous remission; and the need to initiate appropriate treatment early, to avoid the long-term physical and psychosocial morbidity. Current practice is taken from treatment guidelines for adult MG or individual experience, with considerable variability seen across centers. We discuss our approach to treating JMG, in a large specialist JMG service, and review currently available evidence and highlight potential areas for future research. First-line treatment of generalized JMG is symptomatic management with pyridostigmine, but early use of immunosuppression, where good control is not achieved is important. Oral prednisolone is used as first-line immunosuppression with appropriate prevention and monitoring of side effects. Second-line therapies including azathioprine and mycophenolate may be considered where there is: no response to steroids, inability to wean to a reasonable minimum effective dose or if side-effects are intolerable. Management of ocular JMG is similar, but requires close involvement of ophthalmology in young children to prevent amblyopia. Muscle-specific tyrosine kinase (MuSK)-JMG show a poorer response to pyridostigmine and anecdotal evidence suggests that rituximab should be considered as second-line immunosuppression. Thymectomy is indicated in any patient with a thymoma, and consideration should be given in acetylcholine receptor (AChR) positive JMG allowing time for spontaneous remission. The benefit is less clear in ocular JMG and is not advised in MuSK-JMG. Children experiencing a myasthenic crisis require urgent hospital admission with access to the intensive care unit. PLEX is preferred over IVIG due to rapid onset of action, but this needs to be balanced with feasibility in very young children. Key questions remain in the management of JMG: when to initiate both first- and second-line treatments, choosing between steroid-sparing agents, and determining the optimal dose and treatment duration. We feel that given the rarity of this disease, the establishment of national registries and collaboration across groups will be needed to address these issues and facilitate future drug trials in JMG.
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Affiliation(s)
- Karen O'Connell
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
| | - Sithara Ramdas
- Department of Paediatric Neurology, John Radcliffe Hospital, Oxford, United Kingdom
| | - Jacqueline Palace
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford, United Kingdom
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21
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Repka MX. Don't Miss This! Red Flags in the Pediatric Eye Examination: Ophthalmoplegia in Childhood. J Binocul Vis Ocul Motil 2019; 69:93-97. [PMID: 31329057 DOI: 10.1080/2576117x.2019.1590141] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 02/16/2019] [Accepted: 02/22/2019] [Indexed: 06/10/2023]
Abstract
Paralytic strabismus in children is rare, occurring in about 0.1% of children. This rate is far less common than the 3% rate usually noted for comitant strabismus. The relative rates of ocular motor pareses were fourth nerve palsies in 36%, sixth in 33%, third in 22%, with multiple ocular motor nerve palsies in 9%. In a single population series from Minnesota, few cases were associated with neoplasm. However, institutional case series reports a high rate of neoplasm for acquired third nerve and sixth nerve palsies after excluding trauma and congenital causes. Tumor is rare in children with fourth cranial nerve palsies, usually associated with other neurologic disease. Rare causes of external ophthalmoplegia, to be considered when the motility pattern is variable or not fitting an ocular motor nerve pattern, include myasthenia gravis and congenital fibrosis of the extraocular muscles. Myasthenia most often presents as ptosis with exotropia. Rarer still is involvement of the extraocular muscles in childhood thyroid disease.
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Affiliation(s)
- Michael X Repka
- a Ophthalmology, Johns Hopkins University School of Medicine , Baltimore , Maryland , USA
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22
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Abstract
Myasthenia gravis (MG) is an autoimmune disease caused by antibodies against the acetylcholine receptor (AChR), muscle-specific kinase (MuSK) or other AChR-related proteins in the postsynaptic muscle membrane. Localized or general muscle weakness is the predominant symptom and is induced by the antibodies. Patients are grouped according to the presence of antibodies, symptoms, age at onset and thymus pathology. Diagnosis is straightforward in most patients with typical symptoms and a positive antibody test, although a detailed clinical and neurophysiological examination is important in antibody-negative patients. MG therapy should be ambitious and aim for clinical remission or only mild symptoms with near-normal function and quality of life. Treatment should be based on MG subgroup and includes symptomatic treatment using acetylcholinesterase inhibitors, thymectomy and immunotherapy. Intravenous immunoglobulin and plasma exchange are fast-acting treatments used for disease exacerbations, and intensive care is necessary during exacerbations with respiratory failure. Comorbidity is frequent, particularly in elderly patients. Active physical training should be encouraged.
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Gilhus NE, Hong Y. Maternal myasthenia gravis represents a risk for the child through autoantibody transfer, immunosuppressive therapy and genetic influence. Eur J Neurol 2018; 25:1402-1409. [PMID: 30133097 DOI: 10.1111/ene.13788] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 08/17/2018] [Indexed: 12/16/2022]
Abstract
Females with myasthenia gravis (MG) worry about their disease having negative consequences for their children. Autoimmune disease mechanisms, treatment and heredity could all have an impact on the child. This is a subject review where Web of Science was searched for relevant keywords and combinations. Controlled and prospective studies were included, and also results from selected and unselected patient cohorts, guidelines, consensus papers and reviews. Neonatal MG with temporary muscle weakness occurs in 10% of newborn babies where the mother has MG, due to transplacental transfer of antibodies against acetylcholine receptor (AChR), muscle-specific kinase (MuSK) or lipoprotein receptor-related protein 4 (LRP4). Arthrogryposis and fetal AChR inactivation syndrome with contractures and permanent myopathy are rare events caused by mother's antibodies against fetal type AChR. The MG drugs pyridostigmine, prednisolone and azathioprine are regarded as safe during pregnancy and breastfeeding. Methotrexate, mycophenolate mofetil and cyclophosphamide are teratogenic. Mother's MG implies at least a 10-fold increased risk for MG and other autoimmune diseases in the child. MG females should receive specific information about pregnancy and giving birth. First-line MG treatments should usually be continued during pregnancy. Intravenous immunoglobulin and plasma exchange represent safe treatments for exacerbations. Neonatal MG risk means that MG women should give birth at hospitals experienced in neonatal intensive care. Neonatal MG needs supportive care, rarely also acetylcholine esterase inhibition or intravenous immunoglobulin. Women with MG should be supported in their wish to have children.
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Affiliation(s)
- N E Gilhus
- Department of Clinical Medicine, University of Bergen, Bergen, Norway.,Department of Neurology, Haukeland University Hospital, Bergen, Norway
| | - Y Hong
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
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Popperud TH, Viken MK, Kerty E, Lie BA. Juvenile myasthenia gravis in Norway: HLA-DRB1*04:04 is positively associated with prepubertal onset. PLoS One 2017; 12:e0186383. [PMID: 29036181 PMCID: PMC5643110 DOI: 10.1371/journal.pone.0186383] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 09/30/2017] [Indexed: 01/08/2023] Open
Abstract
Background Juvenile myasthenia gravis (MG) is a rare autoantibody mediated autoimmune disorder targeting the neuromuscular endplate. The clinical hallmark is muscle weakness and fatigability. Disease aetiology is complex, including both genetic and environmental factors. The involvement of genes in the human leukocyte antigen (HLA) is well established in adult MG. However, HLA associations in European juvenile MG have not been studied. This case-control study aimed to investigate and characterize genetic risk factors in prepubertal and postpubertal onset juvenile MG. Methodology/Principal findings A population based Norwegian cohort of 43 juvenile MG patients (17 with prepubertal onset, 26 with postpubertal onset) and 368 controls were included. Next generation sequencing of five HLA loci (HLA-A, -B, -C, -DRB1 and -DQB1) was performed, and a positive association was seen with HLA-B*08 (OR (95% CI) = 3.27 (2.00–5.36), Pc = 0.00003) and HLA-DRB1*04:04 (OR (95% CI) = 2.65 (1.57–4.24), Pc = 0.03). Stratified in postpubertal and prepubertal onset, HLA-DRB1*04:04 was only positively associated with the latter (P = 0.01). The HLA-B*08 allele (12.9% in the controls), previously described associated with early onset adult MG, was most frequently observed in postpubertal onset MG (40.4%, P = 0.0002) but also increased among prepubertal onset MG (23.5%, P = 0.05). Conclusion This study provides novel information about HLA susceptibility alleles in Norwegian juvenile MG where HLA-DRB1*04:04 was associated with prepubertal onset.
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Affiliation(s)
- T. H. Popperud
- Department of Neurology, Oslo University Hospital, Oslo, Norway
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
- Unit for hereditary and inborn neuromuscular disorders, Department of Neurology, Oslo University Hospital, Oslo, Norway
- * E-mail:
| | - M. K. Viken
- Department of Immunology, University of Oslo and Oslo University Hospital, Oslo, Norway
| | - E. Kerty
- Department of Neurology, Oslo University Hospital, Oslo, Norway
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - B. A. Lie
- Department of Immunology, University of Oslo and Oslo University Hospital, Oslo, Norway
- Department of Medical Genetics, University of Oslo and Oslo University Hospital, Oslo, Norway
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