1
|
Ünlü S, Sánchez Navarro BG, Cakan E, Berchtold D, Meleka Hanna R, Vural S, Vural A, Meisel A, Fichtner ML. Exploring the depths of IgG4: insights into autoimmunity and novel treatments. Front Immunol 2024; 15:1346671. [PMID: 38698867 PMCID: PMC11063302 DOI: 10.3389/fimmu.2024.1346671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 02/29/2024] [Indexed: 05/05/2024] Open
Abstract
IgG4 subclass antibodies represent the rarest subclass of IgG antibodies, comprising only 3-5% of antibodies circulating in the bloodstream. These antibodies possess unique structural features, notably their ability to undergo a process known as fragment-antigen binding (Fab)-arm exchange, wherein they exchange half-molecules with other IgG4 antibodies. Functionally, IgG4 antibodies primarily block and exert immunomodulatory effects, particularly in the context of IgE isotype-mediated hypersensitivity reactions. In the context of disease, IgG4 antibodies are prominently observed in various autoimmune diseases combined under the term IgG4 autoimmune diseases (IgG4-AID). These diseases include myasthenia gravis (MG) with autoantibodies against muscle-specific tyrosine kinase (MuSK), nodo-paranodopathies with autoantibodies against paranodal and nodal proteins, pemphigus vulgaris and foliaceus with antibodies against desmoglein and encephalitis with antibodies against LGI1/CASPR2. Additionally, IgG4 antibodies are a prominent feature in the rare entity of IgG4 related disease (IgG4-RD). Intriguingly, both IgG4-AID and IgG4-RD demonstrate a remarkable responsiveness to anti-CD20-mediated B cell depletion therapy (BCDT), suggesting shared underlying immunopathologies. This review aims to provide a comprehensive exploration of B cells, antibody subclasses, and their general properties before examining the distinctive characteristics of IgG4 subclass antibodies in the context of health, IgG4-AID and IgG4-RD. Furthermore, we will examine potential therapeutic strategies for these conditions, with a special focus on leveraging insights gained from anti-CD20-mediated BCDT. Through this analysis, we aim to enhance our understanding of the pathogenesis of IgG4-mediated diseases and identify promising possibilities for targeted therapeutic intervention.
Collapse
Affiliation(s)
- Selen Ünlü
- Koç University Research Center for Translational Medicine (KUTTAM), İstanbul, Türkiye
- Koç University School of Medicine, Istanbul, Türkiye
| | - Blanca G. Sánchez Navarro
- Department of Neurology with Experimental Neurology, Integrated Myasthenia Gravis Center, Neuroscience Clinical Research Center, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Elif Cakan
- Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA, United States
| | - Daniel Berchtold
- Department of Neurology with Experimental Neurology, Integrated Myasthenia Gravis Center, Neuroscience Clinical Research Center, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Rafael Meleka Hanna
- Department of Neurology with Experimental Neurology, Integrated Myasthenia Gravis Center, Neuroscience Clinical Research Center, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Secil Vural
- Koç University Research Center for Translational Medicine (KUTTAM), İstanbul, Türkiye
- Department of Dermatology and Venereology, Koç University School of Medicine, İstanbul, Türkiye
| | - Atay Vural
- Koç University Research Center for Translational Medicine (KUTTAM), İstanbul, Türkiye
- Department of Neurology, Koç University School of Medicine, İstanbul, Türkiye
| | - Andreas Meisel
- Department of Neurology with Experimental Neurology, Integrated Myasthenia Gravis Center, Neuroscience Clinical Research Center, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Miriam L. Fichtner
- Koç University Research Center for Translational Medicine (KUTTAM), İstanbul, Türkiye
- Department of Neurology with Experimental Neurology, Integrated Myasthenia Gravis Center, Neuroscience Clinical Research Center, Charité Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
2
|
Yang X, Zhang W, Chang X, Li Z, Du R, Guo J. Promising efficacy of Low-Dose rituximab in Muscle specific kinase antibody positive Myasthenia Gravis. Neurosci Lett 2024; 818:137561. [PMID: 37984485 DOI: 10.1016/j.neulet.2023.137561] [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: 10/07/2023] [Revised: 11/03/2023] [Accepted: 11/15/2023] [Indexed: 11/22/2023]
Abstract
AIMS The study aims to evaluate the efficacy of low dose rituximab (RTX) in patients with muscle-specific kinase antibody positive myasthenia gravis (MuSK-MG). METHODS This is a single-center, retrospective study. A total of 10 patients with MuSK-MG were admitted to the Department of Neurology, First Hospital, Shanxi Medical University, between April 2021 to April 2023. Of them, 9 patients had been treated with low dose RTX (500 mg every 6 month) and recruited in this study. The clinical information, including the severity before and after RTX treatment, were collected from the medical records. Clinical effectiveness was assessed by Myasthenia Gravis Foundation of America (MGFA)-postintervention status (PIS), MG-related activities of daily living (MG-ADL), Quantitative Myasthenia Gravis (QMG) scores, Myasthenia Gravis Quality of Life 15-item revised (MG-QOL15r), dosage of steroid at the end of follow up. RESULTS All nine patients showed clinical improvement at the final follow-up after low-dose RTX treatment. The mean dose of prednisolone decreased significantly from 50 mg at baseline to 18.33 mg at the last follow-up (z = -3.417, p = 0.001). The administration of low-dose RTX treatment led to significant improvements in ADL levels (Z = -2.675, P < 0.01), QMG score levels (Z = -2.371, P < 0.05) and QOL-15r levels (Z = -2.547, P < 0.01) at last visit. CONCLUSION Low-dose RTX is effective for treating MuSK-MG patients. Longer-term follow-up and larger-scale studies are needed to provide further evidence.
Collapse
Affiliation(s)
- Xishuai Yang
- Department of Neurology, The First Clinical School of Shanxi Medical University, Taiyuan 030000, Shanxi, China; Department of Neurology, Changzhi city people's Hospital, Changzhi 046000, Shanxi, China
| | - Wei Zhang
- Department of Neurology, The First Hospital of Shanxi Medical University, Taiyuan 030000, Shanxi, China
| | - Xueli Chang
- Department of Neurology, The First Hospital of Shanxi Medical University, Taiyuan 030000, Shanxi, China
| | - Zuopeng Li
- Department of Neurology, The First Hospital of Shanxi Medical University, Taiyuan 030000, Shanxi, China
| | - Runquan Du
- Department of Neurology, Changzhi city people's Hospital, Changzhi 046000, Shanxi, China
| | - Junhong Guo
- Department of Neurology, The First Hospital of Shanxi Medical University, Taiyuan 030000, Shanxi, China.
| |
Collapse
|
3
|
Vesperinas-Castro A, Cortés-Vicente E. Rituximab treatment in myasthenia gravis. Front Neurol 2023; 14:1275533. [PMID: 37849836 PMCID: PMC10577386 DOI: 10.3389/fneur.2023.1275533] [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: 08/10/2023] [Accepted: 09/11/2023] [Indexed: 10/19/2023] Open
Abstract
Myasthenia gravis (MG) is a chronic autoimmune disease mediated by antibodies against post-synaptic proteins of the neuromuscular junction. Up to 10%-30% of patients are refractory to conventional treatments. For these patients, rituximab has been used off-label in the recent decades. Rituximab is a monoclonal antibody against the CD20 protein that leads to B cell depletion and to the synthesis of new antibody-secreting plasma cells. Although rituximab was created to treat B-cell lymphoma, its use has widely increased to treat autoimmune diseases. In MG, the benefit of rituximab treatment in MuSK-positive patients seems clear, but a high variability in the results of observational studies and even clinical trials has been reported for AChR-positive patients. Moreover, few evidence has been reported in seronegative MG and juvenile MG and some questions about regimen of administration or monitoring strategies, remains open. In this review, we intend to revise the available literature on this topic and resume the current evidence of effectiveness of Rituximab in MG, with special attention to results on every MG subtype, as well as the administration protocols, monitoring strategies and safety profile of the drug.
Collapse
Affiliation(s)
- Ana Vesperinas-Castro
- Neuromuscular Diseases Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
- Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
- Biomedical Research Institute Sant Pau (IIB Sant Pau), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| | - Elena Cortés-Vicente
- Neuromuscular Diseases Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain
- Department of Medicine, Universitat Autònoma de Barcelona, Barcelona, Spain
- Biomedical Research Institute Sant Pau (IIB Sant Pau), Barcelona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Instituto de Salud Carlos III, Madrid, Spain
| |
Collapse
|
4
|
Nytrova P, Stastna D, Tesar A, Menkyova I, Posova H, Koprivova H, Mikulova V, Hrdy J, Smela G, Horakova D, Rysankova I, Doleckova K, Tyblova M. Immunity following SARS-CoV-2 vaccination in autoimmune neurological disorders treated with rituximab or ocrelizumab. Front Immunol 2023; 14:1149629. [PMID: 37398654 PMCID: PMC10312310 DOI: 10.3389/fimmu.2023.1149629] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Accepted: 05/22/2023] [Indexed: 07/04/2023] Open
Abstract
Background Rituximab (RTX) and ocrelizumab (OCR), B cell-depleting therapy targeting CD20 molecules, affect the humoral immune response after vaccination. How these therapies influence T-cell-mediated immune response against SARS-CoV-2 after immunization remains unclear. We aimed to evaluate the humoral and cellular immune response to the COVID-19 vaccine in a cohort of patients with multiple sclerosis (MS), neuromyelitis optica spectrum disorders (NMOSD), and myasthenia gravis (MG). Methods Patients with MS (83), NMOSD (19), or MG (7) undergoing RTX (n=47) or OCR (n=62) treatment were vaccinated twice with the mRNA BNT162b2 vaccine. Antibodies were quantified using the SARS-CoV-2 IgG chemiluminescence immunoassay, targeting the spike protein. SARS-CoV-2-specific T cell responses were quantified by interferon γ release assays (IGRA). The responses were evaluated at two different time points (4-8 weeks and 16-20 weeks following the 2nd dose of the vaccine). Immunocompetent vaccinated individuals (n=41) were included as controls. Results Almost all immunocompetent controls developed antibodies against the SARS-CoV-2 trimeric spike protein, but only 34.09% of the patients, without a COVID-19 history and undergoing anti-CD20 treatment (via RTX or OCR), seroconverted. This antibody response was higher in patients with intervals of longer than 3 weeks between vaccinations. The duration of therapy was significantly shorter in seroconverted patients (median 24 months), than in the non-seroconverted group. There was no correlation between circulating B cells and the levels of antibodies. Even patients with a low proportion of circulating CD19+ B cells (<1%, 71 patients) had detectable SARS-CoV-2 specific antibody responses. SARS-CoV-2 specific T cell response measured by released interferon γ was detected in 94.39% of the patients, independently of a humoral immune response. Conclusion The majority of MS, MG, and NMOSD patients developed a SARS-CoV-2-specific T cell response. The data suggest that vaccination can induce SARS-CoV-2-specific antibodies in a portion of anti-CD20 treated patients. The seroconversion rate was higher in OCR-treated patients compared to those on RTX. The response represented by levels of antibodies was better in individuals, with intervals of longer than 3 weeks between vaccinations.
Collapse
Affiliation(s)
- Petra Nytrova
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
| | - Dominika Stastna
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
| | - Adam Tesar
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
- Institute of Biophysics and Informatics of the First Faculty of Medicine, Charles University in Prague, Prague, Czechia
| | - Ingrid Menkyova
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
- 2nd Department of Neurology, Faculty of Medicine, Comenius University, Bratislava, Slovakia
| | - Helena Posova
- Laboratory of Clinical Immunology and Allergology, Institute of Clinical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
| | - Helena Koprivova
- Laboratory of Clinical Immunology and Allergology, Institute of Clinical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
| | - Veronika Mikulova
- Laboratory of Clinical Immunology and Allergology, Institute of Clinical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
| | - Jiri Hrdy
- Institute of Immunology and Microbiology, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
| | - Gabriela Smela
- Laboratory of Clinical Immunology and Allergology, Institute of Clinical Biochemistry and Laboratory Diagnostics, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
| | - Dana Horakova
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
| | - Irena Rysankova
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
| | - Kristyna Doleckova
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
| | - Michaela Tyblova
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czechia
| |
Collapse
|
5
|
Nair SS, Jacob S. Novel Immunotherapies for Myasthenia Gravis. Immunotargets Ther 2023; 12:25-45. [PMID: 37038596 PMCID: PMC10082579 DOI: 10.2147/itt.s377056] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 03/03/2023] [Indexed: 04/07/2023] Open
Abstract
Myasthenia gravis (MG), a prototype autoimmune neurological disease, had its therapy centred on corticosteroids, non-steroidal broad-spectrum immunotherapy and cholinesterase inhibitors for several decades. Treatment-refractory MG and long-term toxicities of the medications have been major concerns with the conventional therapies. Advances in the immunology and pathogenesis of MG have ushered in an era of newer therapies which are more specific and efficacious. Complement inhibitors and neonatal Fc receptor blockers target disease-specific pathogenic mechanisms linked to myasthenia and have proven their efficacy in pivotal clinical studies. B cell-depleting agents, specifically rituximab, have also emerged as useful for the treatment of severe MG. Many more biologicals are in the pipeline and in diverse stages of development. This review discusses the evidence for the novel therapies and the specific issues related to their clinical use.
Collapse
Affiliation(s)
- Sruthi S Nair
- Department of Neurology, University Hospitals Birmingham, Birmingham, B15 2TH, UK
- Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India
| | - Saiju Jacob
- Department of Neurology, University Hospitals Birmingham, Birmingham, B15 2TH, UK
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, B15 2TT, UK
| |
Collapse
|
6
|
Chen TX, Fan YT, Peng BW. Distinct mechanisms underlying therapeutic potentials of CD20 in neurological and neuromuscular disease. Pharmacol Ther 2022; 238:108180. [DOI: 10.1016/j.pharmthera.2022.108180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 03/16/2022] [Accepted: 03/28/2022] [Indexed: 10/18/2022]
|
7
|
Long-Term Remission With Low-Dose Rituximab in Myasthenia Gravis: A Retrospective Study. J Clin Neuromuscul Dis 2022; 24:18-25. [PMID: 36005470 DOI: 10.1097/cnd.0000000000000420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJETIVE Rituximab (RTX) is a therapeutic option, for patients with myasthenia gravis (MG) not responding to conventional immunosuppressive treatment. In this cohort, we evaluated long-term efficacy of RTX in the treatment of refractory generalized MG. METHODS A retrospective study was performed in adult patients with refractory generalized MG and at least 24 months of follow-up, between January/2015 and October/2021. The Myasthenia Gravis Status and Treatment Intensity Score was used to assess outcomes, and CD19/CD20+ B-cell counts were monitored. RESULTS Sixteen patients with MG (8 antiacetylcholine receptor+ and 8 muscle-specific antikinase+; mean age 45.5 ± 16.2 years) treated with low-dose RTX protocols were included. CD19/CD20 levels remained undetectable 12 months after induction, and no new relapses were observed during follow-up. CONCLUSIONS Low-dose RTX infusions were sufficient to achieve undetectable CD19/20 cell counts and sustained clinical remission. In low and middle-income countries, the impact of low-dose RTX therapy represents a paradigm shift in decision-making for long-term treatment.
Collapse
|
8
|
Shivaram S, Nagappa M, Varghese N, Seshagiri DV, Duble S, Siddappa SA, Hesarur N, Sinha S, Taly AB. Rituximab in Myasthenia Gravis- Experience from a Low- and Middle-Income Country (LMIC) Setting. Neurol India 2022; 70:1931-1941. [PMID: 36352590 DOI: 10.4103/0028-3886.359277] [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] [Indexed: 06/16/2023]
Abstract
BACKGROUND Myasthenia gravis (MG) is an immune-mediated disorder of the neuromuscular junction. About 10% are refractory to immunosuppressive therapy. AIMS To analyze the response of patients with generalized MG to rituximab. METHODS AND MATERIALS A retrospective review of patients with MG who received rituximab was carried out (n = 13, M:F = 6:7, mean age: 44.84 ± 15.73 years). Myasthenia Gravis Foundation of America (MGFA), MGFA post-intervention status (MGFA-PIS), and Myasthenia Gravis Status and Treatment Intensity (MGSTI) were assessed before and after rituximab. RESULTS The duration of MG was 104.07 ± 92.25 months. Before rituximab, the MGFA was IIA/IIB/IIIA/IIIB/IVB/V in 1/1/2/6/2/1 patients and MGSTI was four in eight patients and six in three patients. The mean duration of follow up was 20.92 ± 14.06 months (range, 4 to 42 months). Dose reduction or discontinuation of cholinesterase inhibitors could be achieved 12 patients. Complete stable remission (CSR) and pharmacologic remission (PR) were achieved in one and four patients respectively and five patients had minimal manifestations. Most patients attained level 0, 1 or 2 MGSTI at last follow up. No rituximab infusion-related adverse events were noted. Three patients had exacerbation of MG between one to five weeks after rituximab administration. Three patients died, one each due to a cardiac event unrelated to MG or treatment, complications related to myasthenic crisis, and coronavirus disease. CONCLUSIONS Rituximab was effective in bringing about remission in MG and can be considered as a first-line agent. However, it has to be administered under close supervision as some patients develop exacerbation of MG akin to steroid-induced worsening.
Collapse
Affiliation(s)
- Sumanth Shivaram
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Madhu Nagappa
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Nibu Varghese
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Doniparthi V Seshagiri
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Shishir Duble
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | | | - Nagabushan Hesarur
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Sanjib Sinha
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| | - Arun B Taly
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bengaluru, Karnataka, India
| |
Collapse
|
9
|
Menon D, Bril V. Pharmacotherapy of Generalized Myasthenia Gravis with Special Emphasis on Newer Biologicals. Drugs 2022; 82:865-887. [PMID: 35639288 PMCID: PMC9152838 DOI: 10.1007/s40265-022-01726-y] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/25/2022] [Indexed: 11/20/2022]
Abstract
Myasthenia gravis (MG) is a chronic, fluctuating, antibody-mediated autoimmune disorder directed against the post-synaptic neuromuscular junctions of skeletal muscles, resulting in a wide spectrum of manifestations ranging from mild to potentially fatal. Given its unique natural course, designing an ideal trial design for MG has been wrought with difficulties and evidence in favour of several of the conventional agents is weak as per current standards. Despite this, acetylcholinesterases and corticosteroids have remained the cornerstones of treatment for several decades with intravenous immunoglobulins (IVIG) and therapeutic plasma exchange (PLEX) offering rapid treatment response, especially in crises. However, the treatment of MG entails long-term immunosuppression and conventional agents are viable options but take longer to act and have a number of class-specific adverse effects. Advances in immunology, translational medicine and drug development have seen the emergence of several newer biological agents which offer selective, target-specific immunotherapy with fewer side effects and rapid onset of action. Eculizumab is one of the newer agents that belong to the class of complement inhibitors and has been approved for the treatment of refractory general MG. Zilucoplan and ravulizumab are other agents in this group in clinical trials. Neisseria meningitis is a concern with all complement inhibitors, mandating vaccination. Neonatal Fc receptor (FcRn) inhibitors prevent immunoglobulin recycling and cause rapid reduction in antibody levels. Efgartigimod is an FcRn inhibitor recently approved for MG treatment, and rozanolixizumab, nipocalimab and batoclimab are other agents in clinical trial development. Although lacking high quality evidence from randomized clinical trials, clinical experience with the use of anti-CD20 rituximab has led to its use in refractory MG. Among novel targets, interleukin 6 (IL6) inhibitors such as satralizumab are promising and currently undergoing evaluation. Cutting-edge therapies include genetically modifying T cells to recognise chimeric antigen receptors (CAR) and chimeric autoantibody receptors (CAAR). These may offer sustained and long-term remissions, but are still in very early stages of evaluation. Hematopoietic stem cell transplantation (HSCT) allows immune resetting and offers sustained remission, but the induction regimens often involve serious systemic toxicity. While MG treatment is moving beyond conventional agents towards target-specific biologicals, lack of knowledge as to the initiation, maintenance, switching, tapering and long-term safety profile necessitates further research. These concerns and the high financial burden of novel agents may hamper widespread clinical use in the near future.
Collapse
Affiliation(s)
- Deepak Menon
- Department of Neurology, National Institute of Mental Health and Neurosciences, Bangalore, India
| | - Vera Bril
- Ellen and Martin Prosserman Centre for Neuromuscular Diseases, University Health Network, 5EC-309, Toronto General Hospital, University of Toronto, 200 Elizabeth St, Toronto, M5G 2C4, Canada.
| |
Collapse
|
10
|
Gelinas D, Parvin-Nejad S, Phillips G, Cole C, Hughes T, Silvestri N, Govindarajan R, Jefferson M, Campbell J, Burnett H. The humanistic burden of myasthenia gravis: A systematic literature review. J Neurol Sci 2022; 437:120268. [DOI: 10.1016/j.jns.2022.120268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 04/14/2022] [Accepted: 04/16/2022] [Indexed: 11/25/2022]
|
11
|
Meng X, Zeng Z, Wang Y, Guo S, Wang C, Wang B, Guo S. Efficacy and Safety of Low-Dose Rituximab in Anti-MuSK Myasthenia Gravis Patients: A Retrospective Study. Neuropsychiatr Dis Treat 2022; 18:953-964. [PMID: 35535211 PMCID: PMC9078430 DOI: 10.2147/ndt.s358851] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Accepted: 04/21/2022] [Indexed: 01/19/2023] Open
Abstract
PURPOSE To evaluate the efficacy and safety of low dosages of rituximab (RTX) in the treatment of MuSK-antibody-positive MG patients. PATIENTS AND METHODS We retrospectively analyzed the data of MuSK-antibody-positive MG patients who were treated with low dosages of RTX from January 2018 to October 2021. The long-term treatment response to RTX was assessed by Myasthenia Gravis Foundation of America (MGFA) post-interventional status (PIS), Myasthenia Gravis Status and Treatment Intensity (MGSTI), dosage of steroid, MG-related activities of daily living (MG-ADL) and myasthenic muscle score (MMS) at the end of follow-up. RESULTS Clinical improvement was observed in all eight patients with follow-up for 8 to 29 months after treatment. At the last visit, complete stable remission had been achieved in one patient, pharmacologic remission in three patients, minimal manifestations status in three patients and improved in one patient based on the MGFA-PIS criteria. MGSTI level 2 or better had been reached in six (75%) patients at the last visit. The steroid dosage decreased from 60 mg at baseline to 15 mg at the last follow-up (p = 0.011). The average MG-ADL score decreased from 11 (range 7 to 15) to 0 (range 0 to 3; p = 0.011), and the MMS improved from 38.5 (range 24 to 60) to 100 (range 90 to 100; p = 0.012). These differences were all statistically significant. During RTX treatment and subsequent follow-up, 1 patient reported minor post-infusion malaise. CONCLUSION Low-dose RTX is effective and safe for treating anti-MuSK antibody positive MG patients. A long-term response is observed after treatment. Larger prospective studies are required to provide further evidence.
Collapse
Affiliation(s)
- Xin Meng
- Department of Neurology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, People's Republic of China
| | - Ziling Zeng
- Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China
| | - Yunda Wang
- Department of Neurosurgery, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China
| | - Shuai Guo
- Department of Neurology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, People's Republic of China
| | - Chunjuan Wang
- Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China
| | - Baojie Wang
- Department of Neurology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, People's Republic of China
| | - Shougang Guo
- Department of Neurology, Shandong Provincial Hospital, Cheeloo College of Medicine, Shandong University, Jinan, Shandong, People's Republic of China.,Department of Neurology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong, People's Republic of China
| |
Collapse
|
12
|
Feng X, Song Z, Wu M, Liu Y, Luo S, Zhao C, Zhang W. Efficacy and Safety of Immunotherapies in Refractory Myasthenia Gravis: A Systematic Review and Meta-Analysis. Front Neurol 2021; 12:725700. [PMID: 34925206 PMCID: PMC8672452 DOI: 10.3389/fneur.2021.725700] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 10/25/2021] [Indexed: 01/21/2023] Open
Abstract
Introduction: Approximately 10–20% of patients WITH myasthenia gravis (MG) are refractory to conventional immunotherapies. The purpose of this study was to conduct a systematic review and meta-analysis to explore the optimal therapies for refractory MG. Method: Correlative studies were performed through a search in PubMed, Cochrane Library, and Embase databases. The primary outcome was defined by changes in the quantitative myasthenia gravis score (QMG). Secondary outcomes were defined by the Myasthenia Gravis Activities of Daily Living Scale (MG-ADL), Myasthenia Gravis Foundation of America (MGFA) post intervention status, adverse events, and disease exacerbation after treatment. Result: A total of 16 studies were included with 403 patients with refractory MG on therapies with rituximab, eculizumab, tacrolimus, and cladribine. Therapeutic efficacy of rituximab and eculizumab was identified with an estimated reduction in QMG score (4.158 vs. 6.928) and MG-ADL (4.400 vs. 4.344), respectively. No significant changes were revealed in efficacy or exacerbation density between the two independent therapeutic cohorts. The estimated adverse event density of eculizumab was more significant than that in the rituximab group (1.195 vs. 0.134 per patient-year), while the estimated serious event density was similar. Conclusion: The efficacy and safety of rituximab and eculizumab have been approved in patients with refractory MG. Rituximab had a superior safety profile than eculizumab with a lower incidence of adverse events. Systematic Review Registration:https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021236818, identifier CRD42021236818.
Collapse
Affiliation(s)
- Xuelin Feng
- Department of Neurology, East Hospital, Tongji University School of Medicine, Shanghai, China.,Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zubiao Song
- Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Mengli Wu
- Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yanmei Liu
- Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Sushan Luo
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Chongbo Zhao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Weixi Zhang
- Department of Neurology, National Key Clinical Department and Key Discipline of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| |
Collapse
|
13
|
Bastakoti S, Kunwar S, Poudel S, Quinonez J, Bista S, Singh N, Jha V, Ruxmohan S, Paesani S, Cueva W, Michel J. Rituximab in the Management of Refractory Myasthenia Gravis and Variability of Its Efficacy in Anti-MuSK Positive and Anti-AChR Positive Myasthenia Gravis. Cureus 2021; 13:e19416. [PMID: 34909332 PMCID: PMC8660595 DOI: 10.7759/cureus.19416] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/09/2021] [Indexed: 01/13/2023] Open
Abstract
Myasthenia gravis affects the neuromuscular junction of the skeletal muscles. It results in muscle weakness involving skeletal muscles (diaphragm, extraocular muscles) and myasthenic crisis. Treatment options for myasthenia gravis management have expanded, including azathioprine, corticosteroids, plasma exchange, and tacrolimus. Unfortunately, a few cases of myasthenia gravis don't respond to conventional treatment modalities. Monoclonal antibodies, rituximab (RTX), are novel treatments that have garnered interest as of late due to their efficacy within the patient population presented with refractory form myasthenia gravis. This review aims to showcase how RTX is an effective treatment within different forms of myasthenia gravis. A limited review was performed using databases that include PubMed and Google Scholar. The following keywords were used: "myasthenia gravis," "rituximab," "monoclonal antibody," "anti-AChR antibody," and "refractory myasthenia." The review focused on case reports, human studies, or research surveys based on the inclusion criteria of human studies involving participants more than 18 years of age and published in English literature. Out of 69 articles, 14 were duplicates, and 29 were relevant and met the inclusion criteria. The findings from the study demonstrate that patients with refractory myasthenia gravis responded well to RTX treatment. Furthermore, RTX has been shown to decrease corticosteroid dependence, induce sustained remission, and have a favorable response to anti-MuSK antibody positive myasthenia gravis compared to anti-AChR antibody positive myasthenia gravis. This literature review suggests that patients with refractory myasthenia gravis can benefit from rituximab; however, it has a variable response in different forms of myasthenia gravis.
Collapse
Affiliation(s)
- Sanjiv Bastakoti
- Division of Research & Acadamic Affairs, Larkin Community Hospital, South Miami, USA.,Internal Medicine, KIST Medical College & Teaching Hospital, Kathmandu, NPL.,Intensive Care Unit, Metrocity Hospital and Research Center, Pokhara, NPL
| | - Saru Kunwar
- Division of Research & Acadamic Affairs, Larkin Community Hospital, South Miami, USA
| | - Sujan Poudel
- Division of Research & Acadamic Affairs, Larkin Community Hospital, South Miami, USA
| | - Jonathan Quinonez
- Neurology/Osteopathic Neuromuscular Medicine, Larkin Community Hospital, South Miami, USA
| | - Seema Bista
- Division of Research & Acadamic Affairs, Larkin Community Hospital, South Miami, USA
| | - Navpreet Singh
- Division of Research & Acadamic Affairs, Larkin Community Hospital, South Miami, USA
| | - Vivek Jha
- Division of Research & Acadamic Affairs, Larkin Community Hospital, South Miami, USA
| | | | - Sylvia Paesani
- Family Medicine, Larkin Community Hospital, South Miami, USA
| | - Wilson Cueva
- Neurology, Larkin Community Hospital, South Miami, USA
| | - Jack Michel
- Internal Medicine, Larkin Health System, South Miami, USA
| |
Collapse
|
14
|
Zhao C, Pu M, Chen D, Shi J, Li Z, Guo J, Zhang G. Effectiveness and Safety of Rituximab for Refractory Myasthenia Gravis: A Systematic Review and Single-Arm Meta-Analysis. Front Neurol 2021; 12:736190. [PMID: 34721267 PMCID: PMC8548630 DOI: 10.3389/fneur.2021.736190] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Accepted: 09/16/2021] [Indexed: 11/13/2022] Open
Abstract
Background and Objective: Myasthenia gravis (MG) is an autoimmune neuromuscular disease. Nearly 10-30% of patients with MG are refractory to conventional therapy. Rituximab (RTX), a monoclonal antibody targeting CD20, is increasingly used in autoimmune disorders. We performed a systematic review and meta-analysis to evaluate the effectiveness and safety of RTX for refractory MG. Methods: Studies published between January 1, 2000 and January 17, 2021 were searched in PubMed, EMBASE, Cochrane Library, and ClincalTrails.gov. Primary outcomes included proportion of patients achieving minimal manifestation status (MMS) or better and quantitative MG (QMG) score change from baseline. Secondary outcomes were glucocorticoids (GC) doses change from baseline and proportion of patients discontinuing oral immunosuppressants. Results: A total of 24 studies involving 417 patients were included in the meta-analysis. An overall 64% (95% confidence interval, 49-77%) of patients achieved MMS or better. The estimated reduction of QMG score was 1.55 (95% confidence interval, 0.88-2.22). The mean reduction of GC doses was 1.46 (95% confidence interval, 1.10-1.82). The proportion of patients discontinuing oral immunosuppressants was 81% (95% confidence interval, 66-93%). Subgroup analyses showed that the proportion of patients achieving MMS or better and discontinuing oral immunosuppressants was higher in MuSK-MG group than those in AChR-MG group. Improvement was more pronounced in patients with mild to moderate MG compared to those with severe MG. Moreover, the efficacy appeared to be independent of the dose of RTX. 19.6% of patients experienced adverse events, most of which were mild to moderate. Only one patient developed progressive multifocal leukoencephalopathy. Conclusions: RTX can alleviate the symptom of weakness, decrease QMG score and reduce the doses of steroids and non-steroid immunosuppressive agents in refractory MG. It is well-tolerated with few severe adverse events. Randomized controlled trials are urgently needed to study the efficacy of RTX in treating refractory MG and to identify the characteristics of patients who might respond well to RTX.
Collapse
Affiliation(s)
- Cong Zhao
- Department of Neurology, Air Force Medical Center of PLA, Beijing, China
| | - Meng Pu
- Department of Hepatobiliary Surgery, Air Force Medical Center of PLA, Beijing, China
| | - Dawei Chen
- Department of Neurology, Air Force Medical Center of PLA, Beijing, China
| | - Jin Shi
- Department of Neurology, Air Force Medical Center of PLA, Beijing, China
| | - Zhuyi Li
- Department of Neurology, Tangdu Hospital, Air Force Medical University, Xi'an, China
| | - Jun Guo
- Department of Neurology, Tangdu Hospital, Air Force Medical University, Xi'an, China
| | - Guangyun Zhang
- Department of Neurology, Air Force Medical Center of PLA, Beijing, China
| |
Collapse
|
15
|
Siddiqi ZA, Nowak RJ, Mozaffar T, O'Brien F, Yountz M, Patti F. Eculizumab in refractory generalized myasthenia gravis previously treated with rituximab: subgroup analysis of REGAIN and its extension study. Muscle Nerve 2021; 64:662-669. [PMID: 34590717 DOI: 10.1002/mus.27422] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 09/16/2021] [Accepted: 09/16/2021] [Indexed: 12/24/2022]
Abstract
INTRODUCTION/AIMS Individuals with refractory generalized myasthenia gravis (gMG) who have a history of rituximab use and experience persistent symptoms represent a population with unmet treatment needs. The aim of this analysis was to evaluate the efficacy and safety of eculizumab in patients with refractory anti-acetylcholine receptor antibody-positive (AChR+ ) gMG previously treated with rituximab. METHODS This post hoc subgroup analysis of the phase 3 REGAIN study (NCT01997229) and its open-label extension (OLE; NCT02301624) compared baseline characteristics, safety, and response to eculizumab in participants who had previously received rituximab with those who had not. Rituximab use was not permitted within the 6 months before screening or during REGAIN/OLE. RESULTS Of 125 REGAIN participants, 14 had received rituximab previously (7 received placebo and 7 received eculizumab). In the previous-rituximab group, 57% had used at least four other immunosuppressants compared with 16% in the no-previous-rituximab group. Myasthenia Gravis Activities of Daily Living total scores from eculizumab baseline to week 130 of eculizumab treatment improved in both the previous-rituximab and no-previous-rituximab groups (least-squares mean -4.4, standard error of the mean [SEM] 1.0 [n = 9] and least-squares mean -4.6, SEM 0.3 [n = 67], respectively; difference = 0.2, 95% confidence interval -1.88 to 2.22). In addition, in both groups, most patients who were treated with eculizumab for 130 weeks achieved a Myasthenia Gravis Foundation of America post-intervention status of minimal manifestations (66.7% and 65.0%, respectively). The eculizumab safety profile was similar between groups and consistent with its established profile. DISCUSSION Eculizumab is an effective therapy for patients with refractory AChR+ gMG, irrespective of whether they had received rituximab treatment previously.
Collapse
Affiliation(s)
- Zaeem A Siddiqi
- Division of Neurology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Richard J Nowak
- Department of Neurology, Yale University School of Medicine, Yale University, New Haven, Connecticut, USA
| | - Tahseen Mozaffar
- Department of Neurology, University of California Irvine, Orange, California, USA
| | - Fanny O'Brien
- Alexion Pharmaceuticals, Inc., Boston, Massachusetts, USA
| | - Marcus Yountz
- Alexion Pharmaceuticals, Inc., Boston, Massachusetts, USA
| | - Francesco Patti
- Department of Medical and Surgical Sciences and Advanced Technologies, G.F. Ingrassia, University of Catania, Catania, Italy
| | | |
Collapse
|
16
|
Fatehi F, Moradi K, Okhovat AA, Shojatalab G, Sedighi B, Boostani R, Sarraf P, Haghi Ashtiani B, Ghasemi M, Moussavi S, Anjidani N, Nafissi S. Zytux in Refractory Myasthenia Gravis: A Multicenter, Open-Labeled, Clinical Trial Study of Effectiveness and Safety of a Rituximab Biosimilar. Front Neurol 2021; 12:682622. [PMID: 34512504 PMCID: PMC8427762 DOI: 10.3389/fneur.2021.682622] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 07/09/2021] [Indexed: 01/10/2023] Open
Abstract
Objectives: Myasthenia gravis (MG) is an immune-mediated neuromuscular disorder responsive to immunomodulatory treatments. 10-20% of MGs are not responsive to conventional first-line therapies. Here, we sought to investigate the efficacy and safety of rituximab therapy in the treatment of patients with refractory MG. Methods: In a 48-week, multicenter, open-labeled, prospective cohort setting, 34 participants with refractory MG were assigned to receive infusions of Zytux, which is a rituximab biosimilar, according to a validated protocol. Clinical, functional, and quality of life (QoL) measurements were recorded at baseline, and seven further visits using the Myasthenia Gravis Foundation of America (MGFA), Myasthenia Gravis Composite (MGC), Myasthenia Gravis Activities of Daily Living profile (MG-ADL), and Myasthenia Gravis Quality of Life (MGQoL-15) scales. Besides, the post-infusion side effects were systematically assessed throughout the study. Results: The correlation analysis performed by generalized estimating equations analysis represented a significant reduction of MGC, MG-ADL, and MGQoL-15 scores across the trial period. The subgroup analysis based on the patients' clinical status indicated a significant effect for the interaction between time and MGFA subtypes on MG-ADL score, MGC score, and pyridostigmine prednisolone dose, reflecting that the worse clinical condition was associated with a better response to rituximab. Finally, no serious adverse event was documented. Conclusions: Rituximab therapy could improve clinical, functional, and QoL in patients with refractory MG in a safe setting. Further investigations with larger sample size and a more extended follow-up period are warranted to confirm this finding. Clinical Trial Registration: The study was registered by the Iranian Registry of Clinical Trials (IRCT) (Code No: IRCT20150303021315N18).
Collapse
Affiliation(s)
- Farzad Fatehi
- Neurology Department, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Kamyar Moradi
- Neurology Department, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Ali Asghar Okhovat
- Neurology Department, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran.,Neurology Department, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Ghazaleh Shojatalab
- Neurology Department, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Behnaz Sedighi
- Neurology Department, Shafa Hospital, Kerman University of Medical Sciences, Kerman, Iran
| | - Reza Boostani
- Neurology Department, Ghaem Hospital, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Payam Sarraf
- Neurology Department, Imam-Khomeini Hospital Complex, Tehran University of Medical Sciences, Tehran, Iran.,Iranian Center of Neurological Research, Tehran University of Medical Sciences, Tehran, Iran
| | - Bahram Haghi Ashtiani
- Department of Neurology, Firoozgar Hospital, Iran University of Medical Sciences, Tehran, Iran
| | - Majid Ghasemi
- Department of Neurology, Kashani Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Soussan Moussavi
- Medical Student, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Nassim Anjidani
- Head of Medical Department, Orchid Pharmed Company, Tehran, Iran
| | - Shahriar Nafissi
- Neurology Department, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran
| |
Collapse
|
17
|
Zografou C, Vakrakou AG, Stathopoulos P. Short- and Long-Lived Autoantibody-Secreting Cells in Autoimmune Neurological Disorders. Front Immunol 2021; 12:686466. [PMID: 34220839 PMCID: PMC8248361 DOI: 10.3389/fimmu.2021.686466] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2021] [Accepted: 05/28/2021] [Indexed: 12/24/2022] Open
Abstract
As B cells differentiate into antibody-secreting cells (ASCs), short-lived plasmablasts (SLPBs) are produced by a primary extrafollicular response, followed by the generation of memory B cells and long-lived plasma cells (LLPCs) in germinal centers (GCs). Generation of IgG4 antibodies is T helper type 2 (Th2) and IL-4, -13, and -10-driven and can occur parallel to IgE, in response to chronic stimulation by allergens and helminths. Although IgG4 antibodies are non-crosslinking and have limited ability to mobilize complement and cellular cytotoxicity, when self-tolerance is lost, they can disrupt ligand-receptor binding and cause a wide range of autoimmune disorders including neurological autoimmunity. In myasthenia gravis with predominantly IgG4 autoantibodies against muscle-specific kinase (MuSK), it has been observed that one-time CD20+ B cell depletion with rituximab commonly leads to long-term remission and a marked reduction in autoantibody titer, pointing to a short-lived nature of autoantibody-secreting cells. This is also observed in other predominantly IgG4 autoantibody-mediated neurological disorders, such as chronic inflammatory demyelinating polyneuropathy and autoimmune encephalitis with autoantibodies against the Ranvier paranode and juxtaparanode, respectively, and extends beyond neurological autoimmunity as well. Although IgG1 autoantibody-mediated neurological disorders can also respond well to rituximab induction therapy in combination with an autoantibody titer drop, remission tends to be less long-lasting and cases where titers are refractory tend to occur more often than in IgG4 autoimmunity. Moreover, presence of GC-like structures in the thymus of myasthenic patients with predominantly IgG1 autoantibodies against the acetylcholine receptor and in ovarian teratomas of autoimmune encephalitis patients with predominantly IgG1 autoantibodies against the N‐methyl‐d‐aspartate receptor (NMDAR) confers increased the ability to generate LLPCs. Here, we review available information on the short-and long-lived nature of ASCs in IgG1 and IgG4 autoantibody-mediated neurological disorders and highlight common mechanisms as well as differences, all of which can inform therapeutic strategies and personalized medical approaches.
Collapse
Affiliation(s)
- C Zografou
- Institute of Neuropathology, University of Zurich, Zurich, Switzerland
| | - A G Vakrakou
- First Department of Neurology, National and Kapodistrian University of Athens Medical School, Athens, Greece
| | - P Stathopoulos
- First Department of Neurology, National and Kapodistrian University of Athens Medical School, Athens, Greece
| |
Collapse
|
18
|
Usman U, Chrisman C, Houston D, Haws CC, Wang A, Muley S. The use of eculizumab in ventilator-dependent myasthenia gravis patients. Muscle Nerve 2021; 64:212-215. [PMID: 34008175 DOI: 10.1002/mus.27326] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Revised: 05/12/2021] [Accepted: 05/16/2021] [Indexed: 01/13/2023]
Abstract
INTRODUCTION/AIMS Eculizumab has been shown to be efficacious in acetylcholine receptor antibody-positive (AChR+ ) Myasthenia Gravis Foundation of America (MGFA) class II, III, and IV generalized myasthenia gravis (gMG) patients. However, it has not been studied in MGFA class V gMG patients. METHODS We report three AChR+ , refractory, MGFA class V gMG patients treated with eculizumab. MGFA class, MG-Composite (MGC) score and MG Activities of Daily Living (MG-ADL) score were assessed before and after eculizumab. RESULTS Two of three gMG patients, refractory to intravenous immunoglobulin, plasmapheresis, prednisone, and (in one case) rituximab, showed a robust response to eculizumab with marked improvement in MGFA, MG-ADL, and MGC measures. The third patient showed a partial response to eculizumab but remained on noninvasive ventilation and gastrostomy intubation. Patients 1 and 2 achieved minimal manifestation status at week 4 and week 6, respectively, and showed continued improvement on MG-ADL and MGC scores through weeks 55 and 43, respectively, with eculizumab. The third patient showed a partial response at week 10, followed by a slight decline in his MG-ADL score, but noted a slow but an incomplete improvement afterward on MG-ADL and MGC scores, possibly due to delayed eculizumab infusion. DISCUSSION Eculizumab may play a role in the treatment of patients with MGFA class V, refractory gMG. Larger studies are required to provide further evidence.
Collapse
Affiliation(s)
- Uzma Usman
- Department of Neurology, Yale University, New Haven, Connecticut, USA
| | - Christina Chrisman
- Department of Neurology, Banner University Medical Centre, Phoenix, AZ, Phoenix, Arizona, USA
| | - Drew Houston
- Department of Neurology, Barrow Neurological Institute. Phoenix. AZ, Phoenix, Arizona, USA
| | - Clara Chow Haws
- Department of Neurology, Phoenix Children Hospital, Phoenix, Arizona, USA
| | - Alan Wang
- Department of Neurology, Banner University Medical Centre, Phoenix, AZ, Phoenix, Arizona, USA
| | - Suraj Muley
- Department of Neurology, Barrow Neurological Institute. Phoenix. AZ, Phoenix, Arizona, USA
| |
Collapse
|
19
|
Abstract
Introduction: Myasthenia gravis (MG) is an antibody-mediated disease with diverse serology and clinical presentation. Currently, MG is managed by untargeted immunomodulatory agents. About 15% patients are refractory to these therapies. Several novel and targeted treatments are on the horizon. Rituximab, a monoclonal antibody, is reported to be highly effective with widespread oof-label usage in MG, particularly in patients with antibody against muscle-specific kinase or refractory disease. However, a recent trial showed negative results. Compared to conventional oral immunosuppressive therapies used in MG, Rituximab has several benefits. Regular hematological monitoring is not required though serious side effects can occur. Current status of Rituximab in MG and newer immunosuppressants is discussed.Areas explored: Biologic features, clinical effectiveness, safety profile, and newer preparations of Rituximab.Expert opinion: Rituximab provides a promising option for management of MG, particularly in patients with muscle-specific kinase antibodies or those with refractory disease. Several knowledge gaps remain due to scarcity of data from randomized controlled studies. Despite lack of regulatory approval Rituximab has found widespread usage in MG. Large, well-designed studies are needed to assess the comparative efficacy of Rituximab and its optimal regimen in MG.
Collapse
Affiliation(s)
- Zaeem A Siddiqi
- Division of Neurology, Dept of Medicine, University of Alberta Hospital, Edmonton, Canada
| | - Wasim Khan
- Division of Neurology, Dept of Medicine, University of Alberta Hospital, Edmonton, Canada
| | - Faraz S Hussain
- Division of Neurology, Dept of Medicine, University of Alberta Hospital, Edmonton, Canada
| |
Collapse
|
20
|
Ruetsch-Chelli C, Bresch S, Seitz-Polski B, Rosenthal A, Desnuelle C, Cohen M, Brglez V, Ticchioni M, Lebrun-Frenay C. Memory B Cells Predict Relapse in Rituximab-Treated Myasthenia Gravis. Neurotherapeutics 2021; 18:938-948. [PMID: 33768513 PMCID: PMC8423951 DOI: 10.1007/s13311-021-01006-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/17/2020] [Indexed: 12/11/2022] Open
Abstract
Myasthenia gravis can be efficiently treated with rituximab but there is no consensus regarding administration and dose schedules in this indication. No marker has yet been described to predict the clinical relapse of patients. Our objective was to identify the B cell subpopulations predicting clinical relapse in patients suffering from generalized myasthenia gravis and treated with rituximab. Clinical and biological data of 34 patients followed between 2016 and 2019 were prospectively collected every 3 months. Using multiparameter flow cytometry, we assessed the percentage in leucocytes of lymphocytes and several B cell subpopulations measured in residual disease conditions. CD19+ were also measured in non-residual disease conditions. Clinical examinations were performed by neurologists using the Osserman score. Clinical relapse occurred in 14 patients (41%). No patients required ICU or ventilatory assistance. The mean improvement of the Osserman score was 17.18 (3-45) after the first rituximab treatment (p < 0.0001). The mean delay between the first rituximab maintenance cycle and clinical relapse was 386.8 days. At the time of relapse, CD27+ increased (p = 0.0006) with AUC = 0.7654, while CD19+ did not. At a threshold of 0.01%, the sensitivity and specificity of CD19+CD27+ were 75.8% and 72.8%, respectively, and the positive and negative predictive values were 28.0% and 95.6%, respectively. The percentage of memory B cells in whole blood cells can accurately predict clinical relapse in myasthenia gravis patients treated with rituximab. This monitoring allows physicians to tailor rituximab administration and to decrease the number of infusions over time.
Collapse
Affiliation(s)
- Caroline Ruetsch-Chelli
- Laboratoire d'Immunologie, CHU de Nice, Université Côte d'Azur, Nice, France
- Centre Méditerranéen de Médecine Moléculaire (C3M), INSERM U1065, Université Côte d'Azur, Nice Côte d'Azur University, Archet Hospital, 151, route Saint-Antoine de Ginestière CS 23079 -, 06202, Nice, France
- Unité de Recherche Clinique de la Côte d'Azur (UR2CA), Université Côte d'Azur, Nice, France
| | - Saskia Bresch
- Service de Neurologie, Pasteur2, CHU de Nice, Université Côte d'Azur, Nice, France
| | - Barbara Seitz-Polski
- Laboratoire d'Immunologie, CHU de Nice, Université Côte d'Azur, Nice, France
- Unité de Recherche Clinique de la Côte d'Azur (UR2CA), Université Côte d'Azur, Nice, France
| | | | - Claude Desnuelle
- Service de Neurologie, Pasteur2, CHU de Nice, Université Côte d'Azur, Nice, France
| | - Mikael Cohen
- Service de Neurologie, Pasteur2, CHU de Nice, Université Côte d'Azur, Nice, France
- Unité de Recherche Clinique de la Côte d'Azur (UR2CA), Université Côte d'Azur, Nice, France
| | - Vesna Brglez
- Unité de Recherche Clinique de la Côte d'Azur (UR2CA), Université Côte d'Azur, Nice, France
| | - Michel Ticchioni
- Laboratoire d'Immunologie, CHU de Nice, Université Côte d'Azur, Nice, France
- Centre Méditerranéen de Médecine Moléculaire (C3M), INSERM U1065, Université Côte d'Azur, Nice Côte d'Azur University, Archet Hospital, 151, route Saint-Antoine de Ginestière CS 23079 -, 06202, Nice, France
| | - Christine Lebrun-Frenay
- Service de Neurologie, Pasteur2, CHU de Nice, Université Côte d'Azur, Nice, France.
- Unité de Recherche Clinique de la Côte d'Azur (UR2CA), Université Côte d'Azur, Nice, France.
| |
Collapse
|
21
|
Low-dose rituximab treatment for new-onset generalized myasthenia gravis. J Neuroimmunol 2021; 354:577528. [PMID: 33662696 DOI: 10.1016/j.jneuroim.2021.577528] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2020] [Revised: 01/24/2021] [Accepted: 02/21/2021] [Indexed: 01/18/2023]
Abstract
The aim of this retrospective case series study was to evaluate the response and durability of rituximab in patients with new-onset acetylcholine receptor positive (AChR +) generalized myasthenia gravis (MG). Patients were initiated with low-dose rituximab treatment within 3.5 months of onset without concomitant oral immunosuppressants. Seventeen patients (89%) remained relapse-free with a mean follow-up of 51.3 months. Clinical improvement was observed in parallel with the maintenance of low-dose corticosteroids or the complete discontinuation of corticosteroids. Long-term depletion of B cells with low-dose rituximab treatment has shown favorable efficacy and tolerance in reducing disease activity for AChR+ generalized MG.
Collapse
|
22
|
Li T, Zhang GQ, Li Y, Dong SA, Wang N, Yi M, Qi Y, Zhai H, Yang L, Shi FD, Yang CS. Efficacy and safety of different dosages of rituximab for refractory generalized AChR myasthenia gravis: A meta-analysis. J Clin Neurosci 2021; 85:6-12. [PMID: 33581791 DOI: 10.1016/j.jocn.2020.11.043] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Accepted: 11/23/2020] [Indexed: 12/12/2022]
Abstract
BACKGROUND Rituximab (RTX) is a mouse-human chimeric anti-CD20 monoclonal antibody and has been increasingly used for preventing relapses in myasthenia gravis (MG). However, the appropriate dose for maximizing the beneficial effects in refractory MG with acetylcholine receptor (AChR) autoantibody is a long-standing and critical debating question. METHODS We performed a meta-analysis to evaluate the efficacy and safety of the different doses of RTX in 260 refractory AChR-MG patients. RESULTS The AChR-MG patients were divided into low or routine RTX dose groups. An overall proportion of 77% (p = 0.000) AChR-MG patients demonstrated improved clinical status as indicated by the Myasthenia Gravis Foundation of America post-intervention scale (MGFA-PIS). There were 77.1% patients showed improved clinical status in lower dose of RTX group (p = 0.000) and 76.8% in routine protocol group (p = 0.000). Although we found there was no significant difference in the proportion of AChR-MG patients with improved clinical status or adverse reactions between the two groups, adverse reactions might be lower in the lower dose RTX group. CONCLUSION Most of refractory MG patients with anti-AChR autoantibody were well responsive and tolerated to RTX treatment. Repeated application of lower dose of RTX was effective and might be more appropriate for refractory AChR-MG patients with potential lower side effects.
Collapse
Affiliation(s)
- Ting Li
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Guo-Qian Zhang
- Department of Clinical Laboratory, First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin 300193, China
| | - Yue Li
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Shu-An Dong
- Department of Anesthesiology, Tianjin Hospital of Integrated Traditional Chinese and Western Medicine, Tianjin 300100, China
| | - Nan Wang
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Ming Yi
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Yuan Qi
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Hui Zhai
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Li Yang
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China
| | - Fu-Dong Shi
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China; Department of Neurology, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, AZ 85013, USA
| | - Chun-Sheng Yang
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin 300052, China.
| |
Collapse
|
23
|
Bennani HN, Lagrange E, Noble J, Malvezzi P, Motte L, Chevallier E, Rostaing L, Jouve T. Treatment of refractory myasthenia gravis by double-filtration plasmapheresis and rituximab: A case series of nine patients and literature review. J Clin Apher 2020; 36:348-363. [PMID: 33349954 DOI: 10.1002/jca.21868] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 12/03/2020] [Accepted: 12/08/2020] [Indexed: 12/13/2022]
Abstract
INTRODUCTION Myasthenia gravis (MG) is an autoimmune disease mediated by circulating autoantibodies (anti-AchR, anti-MuSK, etc.). More than 20% of myasthenic patients are refractory to conventional treatments (plasma exchange, IVIg, steroids, azathioprine, mycophenolate mofetil). Rituximab (B-lymphocyte-depleting anti-CD20) and apheresis (double-filtration plasmapheresis [DFPP] and immunoadsorption [IA]) are interesting therapeutic alternatives. METHODS This monocentric pilot study included nine refractory myasthenic patients (March 2018 to May 2020) treated by DFPP and/or IA associated with rituximab (375 mg/m2 ). Clinical responses were assessed using the Myasthenia Gravis Foundation of America (MGFA) score. RESULTS Average age of patients was 53 ± 17 years. Gender ratio (M/F) was 3:6. The combination of apheresis and rituximab reduced median MGFA score from IV to II after 12 months of follow-up. Clinical improvement assessed by MGFA score was sustained in the long-term for all patients, during an average follow-up of 14 ± 9 months, allowing them to be self-sufficient and out sick-leave. The median number of apheresis sessions was 7 (5-30). The dose of prednisolone was reduced in two patients from 40 mg/d and 30 mg/d to 7.5 mg/d and 10 mg/d, respectively. It was stopped in a patient who was taking 30 mg/d. No infectious, bleeding, or thrombosis complications were noted. CONCLUSION The combination of rituximab and DFPP was effective to treat refractory MG.
Collapse
Affiliation(s)
- Hamza N Bennani
- Service de Néphrologie, Hémodialyse, Aphérèses et Transplantation Rénale, CHU Grenoble, La Tronche, France
| | - Emmeline Lagrange
- Exploration Fonctionnelle du Système Nerveux instead of Service de Neurologie, CHU Grenoble, La Tronche, France
| | - Johan Noble
- Service de Néphrologie, Hémodialyse, Aphérèses et Transplantation Rénale, CHU Grenoble, La Tronche, France
| | - Paolo Malvezzi
- Service de Néphrologie, Hémodialyse, Aphérèses et Transplantation Rénale, CHU Grenoble, La Tronche, France
| | - Lionel Motte
- Service de Néphrologie, Hémodialyse, Aphérèses et Transplantation Rénale, CHU Grenoble, La Tronche, France
| | - Eloi Chevallier
- Service de Néphrologie, Hémodialyse, Aphérèses et Transplantation Rénale, CHU Grenoble, La Tronche, France
| | - Lionel Rostaing
- Service de Néphrologie, Hémodialyse, Aphérèses et Transplantation Rénale, CHU Grenoble, La Tronche, France.,Université Grenoble-Alpes, La Tronche, France
| | - Thomas Jouve
- Service de Néphrologie, Hémodialyse, Aphérèses et Transplantation Rénale, CHU Grenoble, La Tronche, France.,Université Grenoble-Alpes, La Tronche, France
| |
Collapse
|
24
|
Cavalcante P, Mantegazza R, Bernasconi P. Pharmacogenetic and pharmaco-miR biomarkers for tailoring and monitoring myasthenia gravis treatments. EXPERT REVIEW OF PRECISION MEDICINE AND DRUG DEVELOPMENT 2020. [DOI: 10.1080/23808993.2020.1804865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Affiliation(s)
- Paola Cavalcante
- Neurology IV Unit ‒ Neuroimmunology and Neuromuscular Diseases, Fondazione I.R.C.C.S. Istituto Neurologico Carlo Besta, Milan, Italy
| | - Renato Mantegazza
- Neurology IV Unit ‒ Neuroimmunology and Neuromuscular Diseases, Fondazione I.R.C.C.S. Istituto Neurologico Carlo Besta, Milan, Italy
| | - Pia Bernasconi
- Neurology IV Unit ‒ Neuroimmunology and Neuromuscular Diseases, Fondazione I.R.C.C.S. Istituto Neurologico Carlo Besta, Milan, Italy
| |
Collapse
|
25
|
Farrugia ME, Goodfellow JA. A Practical Approach to Managing Patients With Myasthenia Gravis-Opinions and a Review of the Literature. Front Neurol 2020; 11:604. [PMID: 32733360 PMCID: PMC7358547 DOI: 10.3389/fneur.2020.00604] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Accepted: 05/25/2020] [Indexed: 12/14/2022] Open
Abstract
When the diagnosis of myasthenia gravis (MG) has been secured, the aim of management should be prompt symptom control and the induction of remission or minimal manifestations. Symptom control, with acetylcholinesterase inhibitors such as pyridostigmine, is commonly employed. This may be sufficient in mild disease. There is no single universally accepted treatment regimen. Corticosteroids are the mainstay of immunosuppressive treatment in patients with more than mild MG to induce remission. Immunosuppressive therapies, such as azathioprine are prescribed in addition to but sometimes instead of corticosteroids when background comorbidities preclude or restrict the use of steroids. Rituximab has a role in refractory MG, while plasmapheresis and immunoglobulin therapy are commonly prescribed to treat MG crisis and in some cases of refractory MG. Data from the MGTX trial showed clear evidence that thymectomy is beneficial in patients with acetylcholine receptor (AChR) antibody positive generalized MG, up to the age of 65 years. Minimally invasive thymectomy surgery including robotic-assisted thymectomy surgery has further revolutionized thymectomy and the management of MG. Ocular MG is not life-threatening but can be significantly disabling when diplopia is persistent. There is evidence to support early treatment with corticosteroids when ocular motility is abnormal and fails to respond to symptomatic treatment. Treatment needs to be individualized in the older age-group depending on specific comorbidities. In the younger age-groups, particularly in women, consideration must be given to the potential teratogenicity of certain therapies. Novel therapies are being developed and trialed, including ones that inhibit complement-induced immunological pathways or interfere with antibody-recycling pathways. Fatigue is common in MG and should be duly identified from fatigable weakness and managed with a combination of physical therapy with or without psychological support. MG patients may also develop dysfunctional breathing and the necessary respiratory physiotherapy techniques need to be implemented to alleviate the patient's symptoms of dyspnoea. In this review, we discuss various facets of myasthenia management in adults with ocular and generalized disease, including some practical approaches and our personal opinions based on our experience.
Collapse
Affiliation(s)
- Maria Elena Farrugia
- Neurology Department, Institute of Neurological Sciences, Queen Elizabeth University Hospital, Glasgow, United Kingdom
| | - John A Goodfellow
- Neurology Department, Institute of Neurological Sciences, Queen Elizabeth University Hospital, Glasgow, United Kingdom.,Neuroimmunology Laboratory, Laboratory Medicine and Facilities Building, Queen Elizabeth University Hospital, Glasgow, United Kingdom
| |
Collapse
|
26
|
Abstract
PURPOSE OF REVIEW This article provides an update on the most recent advances in diagnostic procedures and therapeutic approaches for myasthenia gravis, spanning from autoantibody and neuroelectrophysiological tests as diagnostic tools, to innovative and promising treatments based on biological drugs. RECENT FINDINGS Novel studies performed by cell-based assays (CBAs) indicate an improvement in the chance of identifying serum autoantibodies in myasthenic patients. Clinical trials on the use of biological drugs were recently concluded, providing important data on safety and efficacy of eculizumab, efgartigimod and amifampridine phosphate: the first, a complement blocker, showed long-term safety and efficacy in acetylcholine receptor (AChR)-positive myasthenic patients with refractory generalized disease; the second, the neonatal Fc receptor blocker, was well tolerated and clinically effective in both AChR-specific and muscle-specific kinase receptor (MuSK)-positive patients; the third, a blocker of presynaptic potassium channels, was found to be well tolerated and effective in MuSK-positive patients. SUMMARY CBAs can lead to a significant reduction of seronegative patients, improving myasthenia gravis diagnostic process. New biological drugs offer innovative approaches to treat myasthenic patients with generalized disease, promising to change the paradigm of treatment and to significantly enhance therapeutic success within a precision medicine framework.
Collapse
|
27
|
Di Stefano V, Lupica A, Rispoli MG, Di Muzio A, Brighina F, Rodolico C. Rituximab in AChR subtype of myasthenia gravis: systematic review. J Neurol Neurosurg Psychiatry 2020; 91:392-395. [PMID: 32098874 DOI: 10.1136/jnnp-2019-322606] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 02/04/2020] [Accepted: 02/05/2020] [Indexed: 11/03/2022]
Abstract
Myasthenia gravis (MG) is a chronic autoimmune disorder of the neuromuscular junction characterised by an autoantibody against acetylcholine receptor (AChR-Ab), autoantibody against muscle-specific kinase (MuSK-Ab), lipoprotein-related protein 4 or agrin in the postsynaptic membrane at the neuromuscular junction. Many patients are resistant to conventional treatment and effective therapies are needed. Rituximab (RTX) is a monoclonal antibody directed against CD20 antigen on B cells which has been successfully employed in anti-MuSK-Ab+MG, but the efficacy in anti-AChR-Ab+MG is still debated. The purpose of this systematic review was to describe the best evidence for RTX in the acetylcholine receptor subtype. The authors undertook a literature search during the period of 1999-2019 according to the Preferred Reporting Items for Systematic Reviews and Meta-Analys methodology, employing (myasthenia)+(gravis)+(RTX) as search terms. The analysis was confined to studies that include at least five patients with confirmed anti-AChR-Ab+MG. Thirteen studies have been selected, showing a good safety. The data obtained were heterogeneous in terms of posology, administration scheme and patients' evaluation, ranging from a minimum of two to a maximum of three cycles. RTX led to a sustained clinical improvement with prolonged time to relapse, in parallel to a reduction or discontinuation of other immunosuppressive therapies. Treatment with RTX appears to work in some but not all patients with anti-AChR-Ab+MG, but randomised controlled trials are needed. Future studies should take into account the subtype of MG and employ reliable measures of outcome and severity focusing on how to identify patients who may benefit from the treatment. Trial registration number: NCT02110706.
Collapse
Affiliation(s)
- Vincenzo Di Stefano
- Department of Biomedicine, Neuroscience and advanced Diagnostic, University of Palermo, Palermo, Sicily, Italy .,Department of Neuroscience Imaging and Clinical Sciences, Gabriele d'Annunzio University of Chieti and Pescara, Chieti, Abruzzo, Italy
| | - Antonino Lupica
- Department of Clinical and Experimental Medicine, Unit of Neurology and Neuromuscular Disease, University of Messina, Messina, Sicilia, Italy
| | - Marianna Gabriella Rispoli
- Department of Neuroscience Imaging and Clinical Sciences, Gabriele d'Annunzio University of Chieti and Pescara, Chieti, Abruzzo, Italy
| | - Antonio Di Muzio
- Department of Neurology, SS Annunziata Hospital, Chieti, Abruzzo, Italy
| | - Filippo Brighina
- Department of Biomedicine, Neuroscience and advanced Diagnostic, University of Palermo, Palermo, Sicily, Italy
| | - Carmelo Rodolico
- Department of Clinical and Experimental Medicine, Unit of Neurology and Neuromuscular Disease, University of Messina, Messina, Sicilia, Italy
| |
Collapse
|
28
|
Lu J, Zhong H, Jing S, Wang L, Xi J, Lu J, Zhou L, Zhao C. Low-dose rituximab every 6 months for the treatment of acetylcholine receptor-positive refractory generalized myasthenia gravis. Muscle Nerve 2020; 61:311-315. [PMID: 31875994 DOI: 10.1002/mus.26790] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 12/17/2019] [Accepted: 12/20/2019] [Indexed: 12/31/2022]
Abstract
INTRODUCTION In this prospective, open-label study we explore the effectiveness of low-dose rituximab every 6 months in treating refractory generalized myasthenia gravis (GMG). METHODS Twelve patients with acetylcholine receptor (AChR)-positive refractory GMG were enrolled for the study. The primary endpoint was the change in quantitative myasthenia gravis (QMG) score from baseline to the study end. Secondary endpoints included changes in manual muscle testing (MMT), MG-Related Activities of Daily Living (MG-ADL), and 15-item Quality-of-Life (MGQOL-15) scores, as well as prednisolone reduction. RESULTS MG decreased from 18.25 ± 4.03 to 8.42 ± 3.99 (P = .0001), MMT from 27.50 ± 17.78 to 4.58 ± 4.34 (P = .0001), ADL from 8.50 ± 2.84 to 1.17 ± 1.27 (P < .0001), MGQOL-15 from 37.25 ± 13.78 to 17.50 ± 9.73 (P = .0015), and prednisolone dose from 29.38 ± 11.92 mg/day to 8.86 ± 1.88 mg/day (P ≤ .01). DISCUSSION Low-dose rituximab every 6 months is effective in treating refractory GMG patients.
Collapse
Affiliation(s)
- Jun Lu
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Huahua Zhong
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Sisi Jing
- Department of Neurology, Jing'an District Centre Hospital of Shanghai, Fudan University, Shanghai, China
| | - Liang Wang
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Jianying Xi
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Jiahong Lu
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Lei Zhou
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| | - Chongbo Zhao
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai, China
| |
Collapse
|
29
|
Maintenance immunosuppression in myasthenia gravis, an update. J Neurol Sci 2019; 410:116648. [PMID: 31901719 DOI: 10.1016/j.jns.2019.116648] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/25/2019] [Accepted: 12/24/2019] [Indexed: 01/08/2023]
Abstract
Therapies for myasthenia gravis (MG) include symptomatic and immunosuppressive/immunomodulatory treatment. Options for immunosuppression include corticosteroids, azathioprine, mycophenolate mofetil, cyclosporine, tacrolimus, methotrexate, rituximab, cyclophosphamide, eculizumab, intravenous immunoglobulin, subcutaneous immunoglobulin, plasmapheresis, and thymectomy. The practical aspects of long-term immunosuppressive therapy in MG are critically reviewed in this article. Application of one or more of these specific therapies is guided based on known efficacy, adverse effect profile, particular disease subtype and severity, and patient co-morbidities.
Collapse
|
30
|
Schneider-Gold C, Hagenacker T, Melzer N, Ruck T. Understanding the burden of refractory myasthenia gravis. Ther Adv Neurol Disord 2019; 12:1756286419832242. [PMID: 30854027 PMCID: PMC6399761 DOI: 10.1177/1756286419832242] [Citation(s) in RCA: 83] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 01/28/2019] [Indexed: 11/15/2022] Open
Abstract
Myasthenia gravis (MG) is an autoantibody-mediated disease that compromises the acetylcholine receptors or associated structures of the postsynaptic membrane of the neuromuscular junction. This leads to impaired neuromuscular transmission and subsequent fluctuating fatigability and weakness of ocular, bulbar, and limb skeletal muscles. Over the past few decades, there have been significant advances in our understanding of the disease pathophysiology and improvements in prognosis due to intensive care medicine and immunomodulation. Despite this, an estimated 10-20% of patients with MG do not achieve an adequate response, are intolerant to conventional treatment, or require chronic treatment with intravenous immunoglobulins or plasma separation procedures. Such patients are regarded as having MG that is 'refractory' to treatment and may represent a distinct clinical subgroup. Because the majority of patients with MG have well-controlled disease, the burden of illness in the minority with refractory disease is poorly understood and may be underestimated. However, clinically these patients are liable to experience extreme fatigue, considerable disability owing to uncontrolled symptoms, and frequent myasthenic crises and hospitalizations. Both acute adverse effects and an increased risk of comorbidity from treatment regimens may contribute to reduced quality of life. As yet, little is known concerning the impact of refractory MG on mental health and health-related quality of life. This review aims to highlight the burden of disease and unmet needs in patients with refractory MG.
Collapse
Affiliation(s)
- Christiane Schneider-Gold
- Department of Neurology, St. Josef-Hospital, Ruhr-University Bochum, Gudrunstrasse 56, Bochum, D-44791, Germany
| | | | | | | |
Collapse
|
31
|
High efficacy of rituximab for myasthenia gravis: a comprehensive nationwide study in Austria. J Neurol 2019; 266:699-706. [DOI: 10.1007/s00415-019-09191-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 01/01/2019] [Accepted: 01/06/2019] [Indexed: 01/09/2023]
|