1
|
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.
Collapse
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.
| |
Collapse
|
2
|
Mishra AK, Varma A. Myasthenia Gravis: A Systematic Review. Cureus 2023; 15:e50017. [PMID: 38186498 PMCID: PMC10767470 DOI: 10.7759/cureus.50017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 12/06/2023] [Indexed: 01/09/2024] Open
Abstract
Myasthenia gravis (MG), a rare disease, is the most common neuromuscular junction problem. It's the quintessential autoimmune disease with ocular, bulbar, respiratory, axial, and limb muscles exhibiting a typical fatigable weakening due to the development of antibodies against the acetylcholine receptor (AChR). Infections, stress, surgeries, thymus gland anomalies, and pharmaceutical side effects can also cause it. Ocular symptoms are initially experienced by most of the sufferers. The majority of the sufferers will go through at least one episode of symptom exacerbation during their illness. The immune system in MG interferes with nerve-muscle communication, causing muscles to become weak and tired quickly. The actual cause is not yet known, but a problem in the thymus gland may be the cause. In a person suffering from this disease, the size of the thymus becomes larger than normal, which is also called thymic hyperplasia. It is more common for women to have early-onset MG (EOMG) than for males to have late-onset MG (LOMG). Merely clinical evidence, encompassing the patients' medical history and physical indications of fluctuating muscle weakness in a specific region, is utilized to diagnose MG. Complementary diagnostic procedures and lab techniques aid in confirming the synaptic dysfunction and characterizing its kind and degree. Early diagnosis and the availability of effective treatments have reduced the burden of severe impairment and high mortality previously associated with MG. Current immunomodulation-based therapies come with side effects brought on by persistent immune suppression. Improved knowledge of this relatively uncommon but curable condition is required among primary carers. The objective of this review is to provide information about MG and to help people recognize its symptoms and start treatment without panic so that the progression of this disease can be stopped and complications can be avoided.
Collapse
Affiliation(s)
- Aneesh K Mishra
- Medicine, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| | - Anuj Varma
- Medicine, Jawaharlal Nehru Medical College, Datta Meghe Institute of Higher Education and Research, Wardha, IND
| |
Collapse
|
3
|
Chen X, Qiu J, Gao Z, Liu B, Zhang C, Yu W, Yang J, Shen Y, Qi L, Yao X, Sun H, Yang X. Myasthenia gravis: Molecular mechanisms and promising therapeutic strategies. Biochem Pharmacol 2023; 218:115872. [PMID: 37865142 DOI: 10.1016/j.bcp.2023.115872] [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: 09/03/2023] [Revised: 10/16/2023] [Accepted: 10/18/2023] [Indexed: 10/23/2023]
Abstract
Myasthenia gravis (MG) is a type of autoimmune disease caused by the blockage of neuromuscular junction transmission owing to the attack of autoantibodies on transmission-related proteins. Related antibodies, such as anti-AChR, anti-MuSK and anti-LRP4 antibodies, can be detected in most patients with MG. Although traditional therapies can control most symptoms, several challenges remain to be addressed, necessitating the development of more effective and safe treatment strategies for MG. With the in-depth exploration on the mechanism and immune targets of MG, effective therapies, especially therapies using biologicals, have been reported recently. Given the important roles of immune cells, cytokines and intercellular interactions in the pathological process of MG, B-cell targeted therapy, T-cell targeted therapy, proteasome inhibitors targeting plasma cell, complement inhibitors, FcRn inhibitors have been developed for the treatment of MG. Although these novel therapies exert good therapeutic effects, they may weaken the immunity and increase the risk of infection in MG patients. This review elaborates on the pathogenesis of MG and discusses the advantages and disadvantages of the strategies of traditional treatment and biologicals. In addition, this review emphasises that combined therapy may have better therapeutic effects and reducing the risk of side effects of treatments, which has great prospects for the treatment of MG. With the deepening of research on immunotherapy targets in MG, novel opportunities and challenges in the treatment of MG will be introduced.
Collapse
Affiliation(s)
- Xin Chen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Jiayi Qiu
- Department of Clinical Medicine, Medical College, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Zihui Gao
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Boya Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Chen Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Weiran Yu
- Department of Clinical Medicine, Medical College, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Jiawen Yang
- Department of Clinical Medicine, Medical College, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Yuntian Shen
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Lei Qi
- Department of Emergency Medicine, Affiliated Hospital of Nantong University, Nantong, Jiangsu Province 226001, PR China
| | - Xinlei Yao
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China.
| | - Hualin Sun
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China.
| | - Xiaoming Yang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Department of Neurology, Affiliated Hospital of Nantong University, Nantong University, Nantong, Jiangsu Province 226001, PR China.
| |
Collapse
|
4
|
Sobierajski T, Lasek-Bal A, Krzystanek M, Gilhus NE. Diagnosis and therapy of myasthenia gravis-the patients' perspective: a cross-sectional study. Front Neurol 2023; 14:1214041. [PMID: 37602258 PMCID: PMC10437051 DOI: 10.3389/fneur.2023.1214041] [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: 05/07/2023] [Accepted: 07/25/2023] [Indexed: 08/22/2023] Open
Abstract
The survey aimed to explore patients' perspectives with myasthenia gravis (MG) toward the diagnosis made and the therapy used to treat MG. The survey was conducted with a quantitative method, using the CAWI technique. A total of 321 people participated in the survey. More than half of the respondents (56.4%) had suffered from MG for less than 10 years. In three out of 10 cases (30.9%), the diagnosis of MG lasted 3 years or longer. The diagnostic delay was significantly longer in female respondents than in the males (p = 0.029). Cholinergic drugs were used in 92.9% of cases initially, and as maintenance therapy in 84.3% of cases. Corticosteroids were used in initiating therapy (45.8%) and as maintenance therapy (46.4%). One in four respondents (25.5%) reported experiencing very strong and strong side effects after using steroids. The side effects from steroid therapy very strong or strong affected overall physical health in 55.9% of respondents, very strong or strong affected self-acceptance in 52%, to a very large or large extent on mental health in 47.1%, and to a very strong or strong extent influenced the performance of daily activities in 28.2%. More than half of the respondents (57.0%) had had a thymectomy. Seven out of 10 respondents (72.0%) declared that the therapy they were on at the time of the survey allowed them (to varying degrees) to control their course of MG. Low therapy acceptance and less well controlled MG was associated with a preference for non-tablet therapies (p = 0.045). Regular follow-up and cooperation with the specialist health care system should improve MG symptoms, activities of daily living, and quality of life.
Collapse
Affiliation(s)
- Tomasz Sobierajski
- The Center of Sociomedical Research, Faculty of Applied Social Sciences and Resocialization, University of Warsaw, Warsaw, Poland
| | - Anetta Lasek-Bal
- Department of Neurology, School of Health Sciences, Medical University of Silesia in Katowice, Katowice, Poland
- Department of Neurology, Upper-Silesian Medical Center of the Medical University of Silesia in Katowice, Katowice, Poland
| | - Marek Krzystanek
- Department and Clinic of Psychiatric Rehabilitation, Faculty of Medical Sciences in Katowice, Medical University of Silesia in Katowice, Katowice, Poland
| | - Nils E. Gilhus
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
- Department of Neurology, Haukeland University Hospital, Bergen, Norway
| |
Collapse
|
5
|
Waheed W, Newman E, Aboukhatwa M, Moin M, Tandan R. Practical Management for Use of Eculizumab in the Treatment of Severe, Refractory, Non-Thymomatous, AChR + Generalized Myasthenia Gravis: A Systematic Review. Ther Clin Risk Manag 2022; 18:699-719. [PMID: 35855752 PMCID: PMC9288180 DOI: 10.2147/tcrm.s266031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Accepted: 07/04/2022] [Indexed: 11/28/2022] Open
Abstract
Myasthenia gravis (MG) is a rare autoimmune disorder caused by specific autoantibodies at the neuromuscular junction. MG is classified by the antigen specificity of these antibodies. Acetylcholine receptor (AChR) antibodies are the most common type (74–88%), followed by anti-muscle specific kinase (MuSK) and other antibodies. While all these antibodies lead to neuromuscular transmission failure, the immuno-pathogenic mechanisms are distinct. Complement activation is a primary driver of AChR antibody-positive MG (AChR+ MG) pathogenesis. This leads to the formation of the membrane attack complex and destruction of AChR receptors and the postsynaptic membrane resulting in impaired neurotransmission and muscle weakness characteristic of MG. Broad-based immune-suppressants like corticosteroids are effective in controlling MG; however, their long-term use can be associated with significant adverse effects. Advances in translational research have led to the development of more directed therapeutic agents that are likely to alter the future of MG treatment. Eculizumab is a humanized monoclonal antibody that inhibits the cleavage of complement protein C5 and is approved for use in generalized MG. In this review, we discuss the pathophysiology of MG; the therapeutic efficacy and tolerability of eculizumab, as well as the practical guidelines for its use in MG; future studies exploring the role of eculizumab in different stages and subtypes of MG subtypes; the optimal duration of therapy and its discontinuation; the characterization of non-responder patients; and the use of biomarkers for monitoring therapy are highlighted. Based on the pathophysiologic mechanisms, emerging therapies and new therapeutic targets are also reviewed.
Collapse
Affiliation(s)
- Waqar Waheed
- Department of Neurological Sciences, The University of Vermont and the University of Vermont Medical Center, Burlington, VT, USA
| | - Eric Newman
- Department of Neurological Sciences, The University of Vermont and the University of Vermont Medical Center, Burlington, VT, USA
| | - Marwa Aboukhatwa
- Pharmacotherapy Department, University of Vermont Medical Center, Burlington, VT, USA
| | - Maryam Moin
- Department of Neurology, University of Illinois College of Medicine, Peoria, IL, USA
| | - Rup Tandan
- Department of Neurological Sciences, The University of Vermont and the University of Vermont Medical Center, Burlington, VT, USA
| |
Collapse
|
6
|
Crudeli C, Reid L, Burg J, Shersher D. Minimally invasive combined approach robotic thymectomy and transcervical total thyroidectomy. BMJ Case Rep 2022; 15:e249292. [PMID: 35459655 PMCID: PMC9036361 DOI: 10.1136/bcr-2022-249292] [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] [Accepted: 04/07/2022] [Indexed: 11/04/2022] Open
Abstract
Myasthenia gravis (MG) is the most common autoimmune disorder affecting the neuromuscular junction in the USA. It is not uncommon for these patients to have concomitant autoimmune diseases including autoimmune thyroid disease. We describe here our method of performing a reproducible robotically assisted one-stage thymectomy and thyroidectomy. An African-American woman presented to our institution with a medical history of hypertension, morbid obesity, type 2 diabetes mellitus, symptomatic MG and symptomatic non-toxic substernal multinodular goitre. A one-stage minimally invasive right-sided robotic radical thymectomy and a transcervical total thyroidectomy with excision of the substernal goitre was successfully performed. The treatment of thyroid and thymus pathologies varies drastically from medical observation to surgery. This combined approach surgery clearly benefits the patient by offering similar operative time, fewer operative and postoperative recovery experiences, decreased anaesthesia risks associated with MG patients through fewer intubations, and a faster return to baseline function.
Collapse
Affiliation(s)
- Connor Crudeli
- Cooper Medical School of Rowan University, Camden, New Jersey, USA
| | - Lisa Reid
- Endocrine Surgery, Cooper University Health Care, Camden, New Jersey, USA
| | - Jennifer Burg
- Cardiothoracic Surgery, Cooper University Health Care, Camden, New Jersey, USA
| | - David Shersher
- Cardiothoracic Surgery, Cooper University Health Care, Camden, New Jersey, USA
| |
Collapse
|
7
|
Menon D, Katzberg H, Barnett C, Pal P, Bezjak A, Keshavjee S, Bril V. Thymoma pathology and myasthenia gravis outcomes. Muscle Nerve 2021; 63:868-873. [PMID: 33675078 DOI: 10.1002/mus.27220] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 02/24/2021] [Accepted: 02/27/2021] [Indexed: 11/05/2022]
Abstract
INTRODUCTION There is limited evidence regarding the impact of World Health Organization (WHO) subtype of thymoma on post-thymectomy outcome of thymoma-associated myasthenia gravis (TAMG). The objective was to determine if the pathological subtypes of thymoma were associated with post-thymectomy outcomes of myasthenia gravis (MG), in patients with TAMG. METHODS We performed a retrospective study of consecutive patients with TAMG who attended the neuromuscular clinic between January 2018 and December 2019 with a minimum follow-up of 1 y after thymectomy. Outcome measures were MG Impairment Index (MGII), single-simple question (SSQ), Myasthenia Gravis Foundation of America post-intervention status (MGFA PIS) and non-responder MG status at last assessment. RESULTS Ninety-five patients were included; mean age at onset was 48.1 ± 12.1 y; 54(56.8%) were females. Thirteen patients developed MG post-thymectomy. The most common thymoma was WHO type B2 in 39 (41.1%). Most patients (40, 42.1%) had Masaoka stage II thymoma. There was no association of thymoma subtypes or Masaoka stage of disease with age, gender, MG phenotype, serology, post-thymectomy onset, interval from onset to thymectomy, MGII, SSQ, MGFA PIS, or non-responder status. Associations were found between positive serology and lower MGII (11.1 ± 14.2 vs 23 ± 12.9, P = .050), thymic follicular hyperplasia (TFH) and higher SSQ (89.3 ± 11.7 vs 80.1 ± 20.2, P-.043), and lack of recurrence and higher SSQ (84.1 ± 18 vs 72.5 ± 20, P = .037). DISCUSSION The WHO pathological subtype of thymoma did not correlate with MG outcomes. However, positive acetylcholine antibody serology, presence of TFH, and non-recurrence of thymoma predict a favorable outcome.
Collapse
Affiliation(s)
- Deepak Menon
- Ellen and Martin Prosserman Centre for Neuromuscular Diseases, University Health Network, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Hans Katzberg
- Ellen and Martin Prosserman Centre for Neuromuscular Diseases, University Health Network, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Carolina Barnett
- Ellen and Martin Prosserman Centre for Neuromuscular Diseases, University Health Network, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Prodipto Pal
- Department of Laboratory Medicine and Pathology, University Health Network, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Andrea Bezjak
- Department of Radiation Oncology, University Health Network, Princess Margaret Cancer Centre, University of Toronto, Toronto, Ontario, Canada
| | - Shaf Keshavjee
- Department of Surgery, University Health Network, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
| | - Vera Bril
- Ellen and Martin Prosserman Centre for Neuromuscular Diseases, University Health Network, Toronto General Hospital, University of Toronto, Toronto, Ontario, Canada
| |
Collapse
|
8
|
Zhao R, Luo S, Zhao C. The role of innate immunity in myasthenia gravis. Autoimmun Rev 2021; 20:102800. [PMID: 33722749 DOI: 10.1016/j.autrev.2021.102800] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 01/22/2021] [Indexed: 12/19/2022]
Abstract
Myasthenia gravis (MG) is a T cell-driven, B cell-mediated and autoantibody-dependent autoimmune disorder against neuromuscular junctions (NMJ). Accumulated evidence has emerged regarding the role of innate immunity in the pathogenesis of MG. In this review, we proposed two hypothesis underlying the pathological mechanism. In the context of gene predisposition, on the one hand, Toll-like receptors (TLRs) pathways were initiated by viral infection in the thymus with MG to generate chemokines and pro-inflammatory cytokines such as Type I interferon (IFN), which facilitate the thymus to function as a tertiary lymphoid organ (TLO). On the another hand, the antibodies against acetylcholine receptors (AChR) generated by thymus then activated the classical pathways on thymus and neuromuscular junction (NMJ). Futher, we also highlight the role of innate immune cells in the pathogenic response. Finally, we provide some future perspectives in developing new therapeutic approaches particularly targeting the innate immunity for MG.
Collapse
Affiliation(s)
- Rui Zhao
- Department of Neurology, Huashan hospital Fudan University, 200040 Shanghai, China
| | - Sushan Luo
- Department of Neurology, Huashan hospital Fudan University, 200040 Shanghai, China
| | - Chongbo Zhao
- Department of Neurology, Huashan hospital Fudan University, 200040 Shanghai, China.
| |
Collapse
|
9
|
Menon D, Barnett C, Bril V. Novel Treatments in Myasthenia Gravis. Front Neurol 2020; 11:538. [PMID: 32714266 PMCID: PMC7344308 DOI: 10.3389/fneur.2020.00538] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2020] [Accepted: 05/14/2020] [Indexed: 01/08/2023] Open
Abstract
Myasthenia gravis (MG) is the prototypical autoimmune disorder caused by specific autoantibodies at the neuromuscular junction. Broad-based immunotherapies, such as corticosteroids, azathioprine, mycophenolate, tacrolimus, and cyclosporine, have been effective in controlling symptoms of myasthenia. While being effective in a majority of MG patients many of these immunosuppressive agents are associated with long-term side effects, often intolerable for patients, and take several months to be effective. With advances in translational research and drug development capabilities, more directed therapeutic agents that can alter the future of MG treatment have been developed. This review focuses on the aberrant immunological processes in MG, the novel agents that target them along with the clinical evidence for efficacy and safety. These agents include terminal complement C5 inhibitors, Fc receptor inhibitors, B cell depleting agents (anti CD 19 and 20 and B cell activating factor [BAFF)]inhibitors), proteosome inhibitors, T cells and cytokine based therapies (chimeric antigen receptor T [CART-T] cell therapy), autologous stem cell transplantation, and subcutaneous immunoglobulin (SCIG). Most of these new agents have advantages over conventional immunosuppressive treatment (IST) for MG therapy in terms of faster onset of action, favourable side effect profile and the potential for a sustained and long-term remission.
Collapse
Affiliation(s)
| | | | - Vera Bril
- Ellen & Martin Prosserman Centre for Neuromuscular Diseases, University Health Network, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
10
|
Hu B, Niu L, Jiang Z, Xu S, Hu Y, Cao K. LncRNA XLOC_003810 promotes T cell activation and inhibits PD-1/PD-L1 expression in patients with myasthenia gravis-related thymoma. Scand J Immunol 2020; 92:e12886. [PMID: 32243615 DOI: 10.1111/sji.12886] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 03/24/2020] [Accepted: 03/27/2020] [Indexed: 12/23/2022]
Abstract
This study aimed to investigate the effect of long non-coding RNA XLOC_003810 on the activation of CD4+ T cells and expression of PD-1/PD-L1 in patients with myasthenia gravis-related thymoma (MG-T). Thymus specimens and thymic mononuclear cells were obtained from MG and MG-T patients or cardiac surgery patients undergoing thoracotomy who were selected as negative controls (NC). XLOC_003810 expression was examined using quantitative real-time PCR (qRT-PCR). Frequency of CD4+ T cells and proportion of CD4+ PD-1+ T cells and CD14+ PD-L1+ monocytes were quantified by flow cytometry. The release of inflammatory cytokines was measured by qRT-PCR and enzyme-linked immunosorbent assay. Compared with the NC group, expression of XLOC_003810, frequency of CD4+ T cells and the production of inflammatory cytokines were increased in patients with MG and MG-T. XLOC_003810 overexpression significantly increased the frequency of CD4+ T cells, facilitated the production of inflammatory cytokines and decreased the proportion of CD4+ PD-1+ T cells and CD14+ PD-L1+ monocytes in the thymic mononuclear cells. In contrast, XLOC_003810 knockdown exerted the opposite effect. Together, XLOC_003810 promotes T cell activation and inhibits PD-1/PD-L1 pathway in patients with MG-T.
Collapse
Affiliation(s)
- Bo Hu
- Department of Orthopedics, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Li Niu
- Department of Radiotherapy, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Zheng Jiang
- Department of Orthopedics, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Shenglin Xu
- Department of Orthopedics, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Yong Hu
- Department of Orthopedics, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Kun Cao
- Department of Orthopedics, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| |
Collapse
|
11
|
Niu L, Jiang J, Yin Y, Hu B. LncRNA XLOC_003810 modulates thymic Th17/Treg balance in myasthenia gravis with thymoma. Clin Exp Pharmacol Physiol 2020; 47:989-996. [PMID: 32048308 DOI: 10.1111/1440-1681.13280] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 01/08/2020] [Accepted: 02/09/2020] [Indexed: 01/27/2023]
Abstract
Imbalance of T helper 17 (Th17)/regulatory T (Treg) cells is involved in the pathogenesis of myasthenia gravis with thymoma (MG-T). Long non-coding RNAs (lncRNAs) are implicated in the regulation of Th17/Treg balance. This study was designed to explore the role of XLOC_003810, a novel lncRNA, in regulating the Th17/Treg balance in MG-T. The thymic CD4+ T cells were isolated from control subjects and MG-T patients. The Th17/Treg balance was evaluated by determining proportions of Th17 and Treg cells and expression of Th17- and Treg- associated molecules. Lentivirus-mediated silencing and overexpression of XLOC_003810 in CD4+ T cells were performed. The results showed that XLOC_003810 expression was higher in MG-T thymic CD4+ T cells than that in the control group. Furthermore, the ratio of Th17/Treg cells, proportion of Th17 cells and levels of Th17-associated molecules were significantly increased, whereas the proportion of Treg cells and levels of Treg-associated molecules were decreased in MG-T thymic CD4+ T cells. Importantly, the Th17/Treg imbalance in MG-T thymic CD4+ T cells was aggravated by XLOC_003810 overexpression, whereas it was attenuated by XLOC_003810 silencing. Collectively, XLOC_003810 modulates thymic Th17/Treg balance in MG-T patients, providing the scientific basis for the clinical targeted therapy of MG-T.
Collapse
Affiliation(s)
- Li Niu
- Department of Radiotherapy, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Jun Jiang
- Department of Radiotherapy, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Ying Yin
- Department of Radiotherapy, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Bo Hu
- Department of Orthopedics, The First Affiliated Hospital of Anhui Medical University, Hefei, China
| |
Collapse
|
12
|
Affiliation(s)
- Amelia Evoli
- Institute of Neurology, Università Cattolica del Sacro Cuore, Roma, Italy
- Fondazione Policlinico Gemelli, IRCCS, Roma, Italy
| | - Elisa Meacci
- Fondazione Policlinico Gemelli, IRCCS, Roma, Italy
- Institute of Thoracic Surgery, Università Cattolica del Sacro Cuore, Roma, Italy
| |
Collapse
|
13
|
Altered naive CD4 + T cell homeostasis in myasthenia gravis and thymoma patients. J Neuroimmunol 2019; 327:10-14. [PMID: 30686546 DOI: 10.1016/j.jneuroim.2019.01.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2018] [Revised: 01/09/2019] [Accepted: 01/09/2019] [Indexed: 11/22/2022]
Abstract
In Myasthenia Gravis (MG) thymic pathologies are often present and thymectomy is used as treatment. By flow cytometry we elucidated alterations of naïve CD4+ T cell homeostasis in MG patients and patients with thymoma. MG patients showed increased absolute numbers of CD31- centralnaïve CD4+ T cells. Thymoma patients displayed a significantly higher fraction of peripheral blood CD31+ thymicnaive T cells. We show an altered naive CD4+ T cell homeostasis in MG patients that might predispose to autoimmunity. Aberrant generation of T cells in thymoma can be detected by an increased frequency of CD31+ thymicnaive CD4+ T cells in the periphery.
Collapse
|
14
|
Li QR, Ni WP, Lei NJ, Yang JY, Xuan XY, Liu PP, Gong GM, Yan F, Feng YS, Zhao R, Du Y. The overexpression of Fra1 disorders the inflammatory cytokine secretion by mTEC of myasthenia gravis thymus. Scand J Immunol 2018; 88:e12676. [PMID: 29807388 DOI: 10.1111/sji.12676] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 05/22/2018] [Indexed: 12/01/2022]
Abstract
The thymus of a myasthenia gravis (MG) patient is often accompanied by and effected with follicular hyperplasia. Inflammatory cytokines in thymus induce the formation of germinal centres (GC). MG thymic inflammatory cytokines are predominantly secreted by stromal cells. Our previous studies revealed that the expression level of the Fra1 protein, which is a Fos member of the activator protein 1 transcription factors (AP-1), was higher in the MG thymus compared with that of the normal thymus. Based on that, we demonstrated that Fra1 was mainly expressed in medulla thymic epithelial cells (mTECs) and that the rate of Fra1 positive mTECs in the MG thymus was higher than normal. In vitro, we found that the expression of CCL-5, CCL-19 and CCL-21 could be regulated by Fra1 in mTEC and that IL-1β, IL-6, IL-8 and ICAM1 were downregulated in the Fra1 overexpression group and upregulated in the Fra1 knock-down group. Meanwhile, we detected that the expression levels of suppressor of cytokine signalling 3 (SOCS3) were significantly upregulated along with the overexpression of Fra1. Hence, we considered that the overexpression of Fra1 disrupted inflammatory cytokine secretion by mTEC in the MG thymus and that STAT3 and SOCS3 were strongly involved in this process.
Collapse
Affiliation(s)
- Q-R Li
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
| | - W-P Ni
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
| | - N-J Lei
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
| | - J-Y Yang
- College of Veterinary Medicine, North West Agriculture and Forestry University, Zhengzhou, China
| | - X-Y Xuan
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
| | - P-P Liu
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
| | - G-M Gong
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
| | - F Yan
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
| | - Y-S Feng
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
| | - R Zhao
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
| | - Y Du
- Department of Immunology, School of Basic Medical, Zhengzhou University, Zhengzhou, China
| |
Collapse
|
15
|
Sudres M, Verdier J, Truffault F, Le Panse R, Berrih-Aknin S. Pathophysiological mechanisms of autoimmunity. Ann N Y Acad Sci 2018; 1413:59-68. [PMID: 29377165 DOI: 10.1111/nyas.13560] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 10/29/2017] [Accepted: 10/30/2017] [Indexed: 12/12/2022]
Abstract
Autoimmune diseases (AIDs) are chronic disorders characterized by inflammatory reactions against self-antigens that can be either systemic or organ specific. AIDs can differ in their epidemiologic features and clinical presentations, yet all share a remarkable complexity. AIDs result from an interplay of genetic and epigenetic factors with environmental components that are associated with imbalances in the immune system. Many of the pathogenic mechanisms of AIDs are also implicated in myasthenia gravis (MG), an AID in which inflammation of the thymus leads to a neuromuscular disorder. Our goal here is to highlight the similarities and differences between MG and other AIDs by reviewing the common transcriptome signatures and the development of germinal centers and by discussing some unresolved questions about autoimmune mechanisms. This review will propose hypotheses to explain the origin of regulatory T (Treg ) cell defects and the causes of chronicity and specificity of AIDs.
Collapse
Affiliation(s)
- Muriel Sudres
- INSERM U974, Paris, France.,UPMC Sorbonne Universités, Paris, France.,AIM, Institut de Myologie, Paris, France
| | - Julien Verdier
- INSERM U974, Paris, France.,UPMC Sorbonne Universités, Paris, France.,AIM, Institut de Myologie, Paris, France
| | - Frédérique Truffault
- INSERM U974, Paris, France.,UPMC Sorbonne Universités, Paris, France.,AIM, Institut de Myologie, Paris, France
| | - Rozen Le Panse
- INSERM U974, Paris, France.,UPMC Sorbonne Universités, Paris, France.,AIM, Institut de Myologie, Paris, France
| | - Sonia Berrih-Aknin
- INSERM U974, Paris, France.,UPMC Sorbonne Universités, Paris, France.,AIM, Institut de Myologie, Paris, France
| |
Collapse
|
16
|
Robinet M, Villeret B, Maillard S, Cron MA, Berrih-Aknin S, Le Panse R. Use of Toll-Like Receptor Agonists to Induce Ectopic Lymphoid Structures in Myasthenia Gravis Mouse Models. Front Immunol 2017; 8:1029. [PMID: 28970832 PMCID: PMC5609563 DOI: 10.3389/fimmu.2017.01029] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Accepted: 08/09/2017] [Indexed: 12/21/2022] Open
Abstract
Myasthenia gravis (MG) is an autoimmune disease mediated by autoantibodies against the acetylcholine receptor (AChR) at the neuromuscular junction. MG symptoms are characterized by muscle weaknesses. The thymus of MG patients is very often abnormal and possesses all the characteristics of tertiary lymphoid organs such as neoangiogenesis processes, overexpression of inflammatory cytokines and chemokines, and infiltration of B lymphocytes leading to ectopic germinal center (GC) development. We previously demonstrated that injections of mice with polyinosinic–polycytidylic acid [Poly(I:C)], a synthetic double-stranded RNA mimicking viral infection, induce thymic changes and trigger MG symptoms. Upon Poly(I:C) injections, we observed increased thymic expressions of α-AChR, interferon-β and chemokines such as CXCL13 and CCL21 leading to B-cell recruitment. However, these changes were only transient. In order to develop an experimental MG model associated with thymic GCs, we used Poly(I:C) in the classical experimental autoimmune MG model induced by immunizations with purified AChR emulsified in complete Freund’s adjuvant. We observed that Poly(I:C) strongly favored the development of MG as almost all mice displayed MG symptoms. Nevertheless, we did not observe any ectopic GC development. We next challenged mice with Poly(I:C) together with other toll-like receptor (TLR) agonists known to be involved in GC development and that are overexpressed in MG thymuses. Imiquimod and CpG oligodeoxynucleotides that activate TLR7 and TLR9, respectively, did not induce thymic changes. In contrast, lipopolysaccharide that activates TLR4 potentiated Poly(I:C) effects and induced a significant expression of CXCL13 mRNA in the thymus associated with a higher recruitment of B cells that induced over time thymic B-lymphoid structures. Altogether, these data suggest that tertiary lymphoid genesis in MG thymus could result from a combined activation of TLR signaling pathways.
Collapse
Affiliation(s)
- Marieke Robinet
- INSERM U974, Paris, France.,UPMC Sorbonne Universités, Paris, France.,AIM, Institut de myologie, Paris, France
| | - Bérengère Villeret
- INSERM U974, Paris, France.,UPMC Sorbonne Universités, Paris, France.,AIM, Institut de myologie, Paris, France
| | - Solène Maillard
- INSERM U974, Paris, France.,UPMC Sorbonne Universités, Paris, France.,AIM, Institut de myologie, Paris, France
| | - Mélanie A Cron
- INSERM U974, Paris, France.,UPMC Sorbonne Universités, Paris, France.,AIM, Institut de myologie, Paris, France
| | - Sonia Berrih-Aknin
- INSERM U974, Paris, France.,UPMC Sorbonne Universités, Paris, France.,AIM, Institut de myologie, Paris, France
| | - Rozen Le Panse
- INSERM U974, Paris, France.,UPMC Sorbonne Universités, Paris, France.,AIM, Institut de myologie, Paris, France
| |
Collapse
|
17
|
Review on Toll-Like Receptor Activation in Myasthenia Gravis: Application to the Development of New Experimental Models. Clin Rev Allergy Immunol 2017; 52:133-147. [PMID: 27207173 DOI: 10.1007/s12016-016-8549-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Abnormal toll-like receptor (TLR) activation and uncontrolled resolution of inflammation are suspected to play a key role in the development of autoimmune diseases. Acquired myasthenia gravis (MG) is an invalidating neuromuscular disease leading to muscle weaknesses. MG is mainly mediated by anti-acetylcholine receptor (AChR) autoantibodies, and thymic hyperplasia characterized by ectopic germinal centers is a common feature in MG. An abnormal expression of certain TLRs is observed in the thymus of MG patients associated with the overexpression of interferon (IFN)-β, the orchestrator of thymic changes in MG. Experimental models have been developed for numerous autoimmune diseases. These models are induced by animal immunization with a purified antigen solubilized in complete Freund's adjuvant (CFA) containing heat-inactivated mycobacterium tuberculosis (MTB). Sensitization against the antigen is mainly due to the activation of TLR signaling pathways by the pathogen motifs displayed by MTB, and attempts have been made to substitute the use of CFA by TLR agonists. AChR emulsified in CFA is used to induce the classical experimental autoimmune MG model (EAMG). However, the TLR4 activator lipopolysaccharide (LPS) has proved to be efficient to replace MTB and induce a sensitization against purified AChR. Poly(I:C), the well-known TLR3 agonist, is also able by itself to induce MG symptoms in mice associated with early thymic changes as observed in human MG. In this review, we discuss the abnormal expression of TLRs in MG patients and we describe the use of TLR agonists to induce EAMG in comparison with other autoimmune experimental models.
Collapse
|
18
|
Novel CXCL13 transgenic mouse: inflammation drives pathogenic effect of CXCL13 in experimental myasthenia gravis. Oncotarget 2016; 7:7550-62. [PMID: 26771137 PMCID: PMC4884937 DOI: 10.18632/oncotarget.6885] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 12/23/2015] [Indexed: 01/17/2023] Open
Abstract
Abnormal overexpression of CXCL13 is observed in many inflamed tissues and in particular in autoimmune diseases. Myasthenia gravis (MG) is a neuromuscular disease mainly mediated by anti-acetylcholine receptor autoantibodies. Thymic hyperplasia characterized by ectopic germinal centers (GCs) is a common feature in MG and is correlated with high levels of anti-AChR antibodies. We previously showed that the B-cell chemoattractant, CXCL13 is overexpressed by thymic epithelial cells in MG patients. We hypothesized that abnormal CXCL13 expression by the thymic epithelium triggered B-cell recruitment in MG. We therefore created a novel transgenic (Tg) mouse with a keratin 5 driven CXCL13 expression. The thymus of Tg mice overexpressed CXCL13 but did not trigger B-cell recruitment. However, in inflammatory conditions, induced by Poly(I:C), B cells strongly migrated to the thymus. Tg mice were also more susceptible to experimental autoimmune MG (EAMG) with stronger clinical signs, higher titers of anti-AChR antibodies, increased thymic B cells, and the development of germinal center-like structures. Consequently, this mouse model finally mimics the thymic pathology observed in human MG. Our data also demonstrated that inflammation is mandatory to reveal CXCL13 ability to recruit B cells and to induce tertiary lymphoid organ development.
Collapse
|
19
|
Affiliation(s)
- Sonia Berrih-Aknin
- INSERM U974; Paris France
- CNRS FRE3617; Paris France
- Sorbonne University; UPMC Univ Paris 06; Paris France
- AIM; Institute of Myology; Paris France
| |
Collapse
|
20
|
Hwang JY, Randall TD, Silva-Sanchez A. Inducible Bronchus-Associated Lymphoid Tissue: Taming Inflammation in the Lung. Front Immunol 2016; 7:258. [PMID: 27446088 PMCID: PMC4928648 DOI: 10.3389/fimmu.2016.00258] [Citation(s) in RCA: 119] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 06/17/2016] [Indexed: 01/09/2023] Open
Abstract
Following pulmonary inflammation, leukocytes that infiltrate the lung often assemble into structures known as inducible Bronchus-Associated Lymphoid Tissue (iBALT). Like conventional lymphoid organs, areas of iBALT have segregated B and T cell areas, specialized stromal cells, high endothelial venules, and lymphatic vessels. After inflammation is resolved, iBALT is maintained for months, independently of inflammation. Once iBALT is formed, it participates in immune responses to pulmonary antigens, including those that are unrelated to the iBALT-initiating antigen, and often alters the clinical course of disease. However, the mechanisms that govern immune responses in iBALT and determine how iBALT impacts local and systemic immunity are poorly understood. Here, we review our current understanding of iBALT formation and discuss how iBALT participates in pulmonary immunity.
Collapse
Affiliation(s)
- Ji Young Hwang
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham , Birmingham, AL , USA
| | - Troy D Randall
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham , Birmingham, AL , USA
| | - Aaron Silva-Sanchez
- Division of Clinical Immunology and Rheumatology, Department of Medicine, University of Alabama at Birmingham , Birmingham, AL , USA
| |
Collapse
|
21
|
A Case Series of Patients With Autoimmune Myasthenia Gravis in Association With Invasive Thymoma. J Clin Neuromuscul Dis 2016; 17:129-34. [PMID: 26905913 DOI: 10.1097/cnd.0000000000000101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES In some patients, autoimmune myasthenia gravis (MG) is associated with thymic hyperplasia or thymoma, and in some patients the thymoma is invasive. Little is known about the clinical course of subjects who present with MG and are found to have invasive thymoma. METHODS We reviewed the patients at our clinic with MG and invasive thymoma, and have described their clinical features. RESULTS Six MG patients were diagnosed with invasive thymoma. The subjects had extensive multimodal therapy. Two subjects died from uncontrolled neuromuscular respiratory failure despite aggressive immunosuppression, 2 subjects had other autoimmune disorders (Morvan syndrome and polymyositis), and 2 subjects are controlled on immunosuppression. CONCLUSIONS Patients with invasive thymoma and MG can have a poor outcome, with difficulty in controlling myasthenic symptoms and can have other clinically important autoimmune diseases.
Collapse
|
22
|
Alahgholi-Hajibehzad M, Kasapoglu P, Jafari R, Rezaei N. The role of T regulatory cells in immunopathogenesis of myasthenia gravis: implications for therapeutics. Expert Rev Clin Immunol 2015; 11:859-70. [DOI: 10.1586/1744666x.2015.1047345] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
23
|
Abstract
A 45-year-old woman with ptosis and diplopia was found to have myasthenia gravis (MG) associated with amyloidosis of the thymus gland. Systemic MG is frequently associated with thymomas or thymic hyperplasia but has only once previously been reported in association with amyloidosis of the thymus. This case demonstrates that isolated ocular MG rarely may also be associated with amyloidosis of the thymus.
Collapse
|
24
|
Bonnan M. [Meningeal tertiary lymphoid organs: Major actors in intrathecal autoimmunity]. Rev Neurol (Paris) 2014; 171:65-74. [PMID: 25555848 DOI: 10.1016/j.neurol.2014.08.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Revised: 07/24/2014] [Accepted: 08/29/2014] [Indexed: 12/29/2022]
Abstract
Multiple sclerosis (MS) is characterized by an intrathecal synthesis of immunoglobulins synthesized by B-cell clones and by a brain infiltrate of clonal T-cells. The clonal maturation of these lymphocytes takes place in tertiary lymphoid organs (TLO) developed in the intrathecal compartment. TLO are acquired lymphoid organs able to develop in the vicinity of the inflammatory sites, where they mount a complete antigen-driven immune response. We here review TLO pathophysiology in animal models of MS and human MS. Several pieces of evidence suggest that intrathecal TLO may play a major role in the clinical impairment. Potential therapeutic applications are examined.
Collapse
Affiliation(s)
- M Bonnan
- Service de neurologie, hôpital F.-Mitterrand, 4, boulevard Hauterive, 64000 Pau, France.
| |
Collapse
|
25
|
Berrih-Aknin S. Myasthenia Gravis: paradox versus paradigm in autoimmunity. J Autoimmun 2014; 52:1-28. [PMID: 24934596 DOI: 10.1016/j.jaut.2014.05.001] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 05/07/2014] [Indexed: 12/12/2022]
Abstract
Myasthenia Gravis (MG) is a paradigm of organ-specific autoimmune disease (AID). It is mediated by antibodies that target the neuromuscular junction. The purpose of this review is to place MG in the general context of autoimmunity, to summarize the common mechanisms between MG and other AIDs, and to describe the specific mechanisms of MG. We have chosen the most common organ-specific AIDs to compare with MG: type 1 diabetes mellitus (T1DM), autoimmune thyroid diseases (AITD), multiple sclerosis (MS), some systemic AIDs (systemic lupus erythematous (SLE), rheumatoid arthritis (RA), Sjogren's syndrome (SS)), as well as inflammatory diseases of the gut and liver (celiac disease (CeD), Crohn's disease (CD), and primary biliary cirrhosis (PBC)). Several features are similar between all AIDs, suggesting that common pathogenic mechanisms lead to their development. In this review, we address the predisposing factors (genetic, epigenetic, hormones, vitamin D, microbiota), the triggering components (infections, drugs) and their interactions with the immune system [1,2]. The dysregulation of the immune system is detailed and includes the role of B cells, Treg cells, Th17 and cytokines. We particularly focused on the role of TNF-α and interferon type I whose role in MG is very analogous to that in several other AIDS. The implication of AIRE, a key factor in central tolerance is also discussed. Finally, if MG is a prototype of AIDS, it has a clear specificity compared to the other AIDS, by the fact that the target organ, the muscle, is not the site of immune infiltration and B cell expansion, but exclusively that of antibody-mediated pathogenic mechanisms. By contrast, the thymus in the early onset subtype frequently undergoes tissue remodeling, resulting in the development of ectopic germinal centers surrounded by high endothelial venules (HEV), as observed in the target organs of many other AIDs.
Collapse
Affiliation(s)
- Sonia Berrih-Aknin
- Sorbonne Universités, UPMC Univ Paris 06, Myology Research Center UM76, F-75013 Paris, France; INSERM U974, F-75013 Paris, France; CNRS FRE 3617, F-75013 Paris, France; Institute of Myology, F-75013 Paris, France.
| |
Collapse
|
26
|
Berrih-Aknin S, Le Panse R. Myasthenia gravis: a comprehensive review of immune dysregulation and etiological mechanisms. J Autoimmun 2014; 52:90-100. [PMID: 24389034 DOI: 10.1016/j.jaut.2013.12.011] [Citation(s) in RCA: 232] [Impact Index Per Article: 23.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 12/12/2013] [Indexed: 12/31/2022]
Abstract
Autoimmune myasthenia gravis (MG) is characterized by muscle weakness caused by antibodies directed against proteins of the neuromuscular junction. The main antigenic target is the acetylcholine receptor (AChR), but the muscle Specific Kinase (MuSK) and the low-density lipoprotein receptor-related protein (LRP4) are also targets. This review summarizes the clinical and biological data available for different subgroups of patients, who are classified according to antigenic target, age of onset, and observed thymic abnormalities, such as follicular hyperplasia or thymoma. Here, we analyze in detail the role of the thymus in the physiopathology of MG and propose an explanation for the development of the thymic follicular hyperplasia that is commonly observed in young female patients with anti-AChR antibodies. The influence of the pro-inflammatory environment is discussed, particularly the role of TNF-α and Th17-related cytokines, which could explain the escape of thymic T cells from regulation and the chronic inflammation in the MG thymus. Together with this immune dysregulation, active angiogenic processes and the upregulation of chemokines could promote thymic follicular hyperplasia. MG is a multifactorial disease, and we review the etiological mechanisms that could lead to its onset. Recent global genetic analyses have highlighted potential susceptibility genes. In addition, miRNAs, which play a crucial role in immune function, have been implicated in MG by recent studies. We also discuss the role of sex hormones and the influence of environmental factors, such as the viral hypothesis. This hypothesis is supported by reports that type I interferon and molecules mimicking viral infection can induce thymic changes similar to those observed in MG patients with anti-AChR antibodies.
Collapse
Affiliation(s)
- Sonia Berrih-Aknin
- INSERM U974, Paris, France; CNRS UMR 7215, Paris, France; UPMC Univ Paris 6, Paris, France; AIM, Institute of myology, Paris, France.
| | - Rozen Le Panse
- INSERM U974, Paris, France; CNRS UMR 7215, Paris, France; UPMC Univ Paris 6, Paris, France; AIM, Institute of myology, Paris, France.
| |
Collapse
|