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1.
Front Immunol ; 15: 1325171, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38715598

RESUMO

Introduction: Muscle-specific kinase (MuSK)- myasthenia gravis (MG) is caused by pathogenic autoantibodies against MuSK that correlate with disease severity and are predominantly of the IgG4 subclass. The first-line treatment for MuSK-MG is general immunosuppression with corticosteroids, but the effect of treatment on IgG4 and MuSK IgG4 levels has not been studied. Methods: We analyzed the clinical data and sera from 52 MuSK-MG patients (45 female, 7 male, median age 49 (range 17-79) years) from Italy, the Netherlands, Greece and Belgium, and 43 AChR-MG patients (22 female, 21 male, median age 63 (range 2-82) years) from Italy, receiving different types of immunosuppression, and sera from 46 age- and sex-matched non-disease controls (with no diagnosed diseases, 38 female, 8 male, median age 51.5 (range 20-68) years) from the Netherlands. We analyzed the disease severity (assessed by MGFA or QMG score), and measured concentrations of MuSK IgG4, MuSK IgG, total IgG4 and total IgG in the sera by ELISA, RIA and nephelometry. Results: We observed that MuSK-MG patients showed a robust clinical improvement and reduction of MuSK IgG after therapy, and that MuSK IgG4 concentrations, but not total IgG4 concentrations, correlated with clinical severity. MuSK IgG and MuSK IgG4 concentrations were reduced after immunosuppression in 4/5 individuals with before-after data, but data from non-linked patient samples showed no difference. Total serum IgG4 levels were within the normal range, with IgG4 levels above threshold (1.35g/L) in 1/52 MuSK-MG, 2/43 AChR-MG patients and 1/45 non-disease controls. MuSK-MG patients improved within the first four years after disease onset, but no further clinical improvement or reduction of MuSK IgG4 were observed four years later, and only 14/52 (26.92%) patients in total, of which 13 (93.3%) received general immunosuppression, reached clinical remission. Discussion: We conclude that MuSK-MG patients improve clinically with general immunosuppression but may require further treatment to reach remission. Longitudinal testing of individual patients may be clinically more useful than single measurements of MuSK IgG4. No significant differences in the serum IgG4 concentrations and IgG4/IgG ratio between AChR- and MuSK-MG patients were found during follow-up. Further studies with larger patient and control cohorts are necessary to validate the findings.


Assuntos
Autoanticorpos , Imunoglobulina G , Miastenia Gravis , Receptores Proteína Tirosina Quinases , Receptores Colinérgicos , Humanos , Miastenia Gravis/imunologia , Miastenia Gravis/sangue , Miastenia Gravis/diagnóstico , Masculino , Pessoa de Meia-Idade , Feminino , Adulto , Idoso , Receptores Proteína Tirosina Quinases/imunologia , Receptores Colinérgicos/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Estudos Retrospectivos , Adulto Jovem , Adolescente , Autoanticorpos/sangue , Autoanticorpos/imunologia , Idoso de 80 Anos ou mais , Terapia de Imunossupressão , Imunossupressores/uso terapêutico , Índice de Gravidade de Doença , Criança
2.
Autoimmunity ; 57(1): 2347379, 2024 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-38723105

RESUMO

Thymoma is closely associated with myasthenia gravis (MG). However, due to the heterogeneity of thymoma and the intricate pathogenesis of MG, it remains unclear why some patients with thymoma develop MG and others do not. In this study, we conducted a comparative phenotype analysis of thymocytes in type B thymomas in patients with MG (MG (+) thymomas) and without MG (MG (-) thymomas) via fluorescence-activated cell sorting (FACS). Our results show that the developmental stages defined by the expression of CD3, CD4, and CD8 were largely maintained in both MG (+) and MG (-) thymomas, with CD4+CD8+ cells constituting the majority of thymocytes in type B thymoma, and no significant difference between this cell population was observed in MG (+) and MG (-) thymomas.We discovered that CD4+CD8+ thymocytes in MG (+) thymomas expressed low levels of αß TCR and high levels of IL-7 receptor α (IL-7Rα), whereas in MG (-) thymomas, CD4+CD8+ thymocytes exhibited the opposite pattern of αß TCR and IL-7Rα expression. These results suggest that the positive and negative selection processes of CD4+CD8+ thymocytes might differ between MG (+) thymomas and MG (-) thymomas. The expression of the Helios transcription factor is induced during negative selection and marks a group of T cells that have undergone negative selection and are likely to be deleted due to strong TCR binding with self-peptides/MHC ligands. We observed that the percentage of Helios-positive CD4SP T cells was greater in MG (-) than in MG (+) thymomas. Thus, the differentially regulated selection process of CD4+CD8+ thymocytes, which involves TCR and IL-7/IL-7Rα signaling, is associated with the presence of MG in type B thymomas.


Assuntos
Miastenia Gravis , Receptores de Antígenos de Linfócitos T alfa-beta , Timócitos , Timoma , Humanos , Timoma/imunologia , Timoma/patologia , Timoma/metabolismo , Miastenia Gravis/imunologia , Miastenia Gravis/patologia , Miastenia Gravis/metabolismo , Receptores de Antígenos de Linfócitos T alfa-beta/metabolismo , Masculino , Timócitos/imunologia , Timócitos/metabolismo , Feminino , Pessoa de Meia-Idade , Receptores de Interleucina-7/metabolismo , Receptores de Interleucina-7/imunologia , Adulto , Idoso , Neoplasias do Timo/imunologia , Neoplasias do Timo/patologia , Neoplasias do Timo/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Imunofenotipagem
3.
Front Immunol ; 15: 1382320, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38711503

RESUMO

Myasthenia gravis (MG), primarily caused by acetylcholine receptor (AChR) autoantibodies, is a chronic autoimmune disorder causing severe muscle weakness and fatigability. In particular, seronegative MG constitutes 10%-15% of MG cases and presents diagnostic challenges especially in early-onset female patients who often show severe disease and resistance to immunosuppressive therapy. Furthermore, the immunopathology of seronegative MG remains unclear. Thus, in this study, we aimed to elucidate the pathogenic mechanism of seronegative MG using scRNA-seq analysis and plasma proteome analysis; in particular, we investigated the relationship between immune dysregulation status and disease severity in refractory seronegative MG. Employing single-cell RNA-sequencing and plasma proteome analyses, we analyzed peripheral blood samples from 30 women divided into three groups: 10 healthy controls, 10 early-onset AChR-positive MG, and 10 refractory early-onset seronegative MG patients, both before and after intravenous immunoglobulin treatment. The disease severity was evaluated using the MG-Activities of Daily Living (ADL), MG composite (MGC), and revised 15-item MG-Quality of Life (QOL) scales. We observed numerical abnormalities in multiple immune cells, particularly B cells, in patients with refractory seronegative MG, correlating with disease activity. Notably, severe MG cases had fewer regulatory T cells without functional abnormalities. Memory B cells were found to be enriched in peripheral blood cells compared with naïve B cells. Moreover, plasma proteome analysis indicated significantly lower plasma protein levels of soluble CD22, expressed in the lineage of B-cell maturation (including mature B cells and memory B cells), in refractory seronegative MG patients than in healthy donors or patients with AChR-positive MG. Soluble CD22 levels were correlated with disease severity, B-cell frequency, and RNA expression levels of CD22. In summary, this study elucidates the immunopathology of refractory seronegative MG, highlighting immune disorders centered on B cells and diminished soluble CD22 levels. These insights pave the way for novel MG treatment strategies focused on B-cell biology.


Assuntos
Linfócitos B , Miastenia Gravis , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico , Humanos , Miastenia Gravis/imunologia , Miastenia Gravis/sangue , Feminino , Adulto , Linfócitos B/imunologia , Lectina 2 Semelhante a Ig de Ligação ao Ácido Siálico/imunologia , Pessoa de Meia-Idade , Autoanticorpos/sangue , Autoanticorpos/imunologia , Imunoglobulinas Intravenosas/uso terapêutico , Receptores Colinérgicos/imunologia , Índice de Gravidade de Doença , Adulto Jovem , Proteoma
4.
J Neuroinflammation ; 21(1): 126, 2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38734662

RESUMO

Myasthenia gravis (MG) is an immune-mediated disease frequently associated with thymic changes. Increased T helper 17 (Th17) cell activity and dysfunctional regulatory T (Treg) cells have been demonstrated in subgroups of MG. On the other hand, hypoxia-inducible factor 1 (HIF-1) has been shown to regulate the Th17/Treg balance by inducing Th17 differentiation while attenuating Treg development. To identify the underlying mechanisms of different thymic pathologies in MG development, we evaluated thymic samples from thymoma-associated myasthenia gravis (TAMG), MG with hyperplasia (TFH-MG) and thymoma without MG (TOMA) patients. Differential gene expression analysis revealed that TAMG and TFH-MG cells are associated with different functional pathways. A higher RORC/FOXP3 ratio provided evidence for Th17/Treg imbalance in TAMG potentially related to increased HIF1A. The hypoxic microenvironment in thymoma may be a driver of TAMG by increasing HIF1A. These findings may lead to new therapeutic approaches targeting HIF1A in the development of TAMG.


Assuntos
Subunidade alfa do Fator 1 Induzível por Hipóxia , Miastenia Gravis , Linfócitos T Reguladores , Células Th17 , Timoma , Timo , Neoplasias do Timo , Miastenia Gravis/genética , Miastenia Gravis/imunologia , Miastenia Gravis/patologia , Timoma/complicações , Timoma/genética , Timoma/imunologia , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Linfócitos T Reguladores/metabolismo , Linfócitos T Reguladores/imunologia , Células Th17/metabolismo , Células Th17/imunologia , Timo/patologia , Masculino , Feminino , Neoplasias do Timo/complicações , Neoplasias do Timo/genética , Adulto , Pessoa de Meia-Idade , Idoso
5.
Brain Nerve ; 76(5): 613-620, 2024 May.
Artigo em Japonês | MEDLINE | ID: mdl-38741504

RESUMO

Herein, we describe the mechanisms, diagnostic procedures, and treatment options for acetylcholine receptor (AChR) antibody-positive myasthenia gravis (MG). The upstream pathomechanism of this condition involves AChR-sensitized T cell-dependent B cell proliferation and the subsequent production of pathogenic autoantibodies. Downstream molecules include AChR antibodies that activate complement pathways, resulting in the destruction of motor endplates. We further introduce newly-developed molecular targeted drugs for the treatment of MG that aims to secure patients' health-related quality of life.


Assuntos
Autoanticorpos , Miastenia Gravis , Receptores Colinérgicos , Miastenia Gravis/imunologia , Miastenia Gravis/diagnóstico , Miastenia Gravis/terapia , Humanos , Receptores Colinérgicos/imunologia , Autoanticorpos/imunologia
6.
Brain Nerve ; 76(5): 623-629, 2024 May.
Artigo em Japonês | MEDLINE | ID: mdl-38741505

RESUMO

Reportedly, patients with muscle-specific kinase (MuSK) antibody-positive myasthenia gravis (MG) account for approximately 3.0% of all patients with MG in Japan. Compared with patients who have acetylcholine receptor antibody-positive MG, those with MuSK antibody-positive MG show young-onset disease with female predominance, a low rate of ocular involvement (5.9%), and greater severity of dysphagia. The aforementioned types of MG are indistinguishable based on clinical symptoms and electrophysiological tests, and measurement of MuSK antibodies is essential for diagnosis. Thymectomy and complement inhibitors are not indicated for treatment, and acetylcholinesterase inhibitors, steroids, immunosuppressants, plasma exchange, intravenous immunoglobulin therapy, and neonatal Fc receptor inhibitors are used.


Assuntos
Autoanticorpos , Miastenia Gravis , Receptores Proteína Tirosina Quinases , Receptores Colinérgicos , Humanos , Miastenia Gravis/imunologia , Miastenia Gravis/diagnóstico , Miastenia Gravis/terapia , Receptores Proteína Tirosina Quinases/imunologia , Receptores Colinérgicos/imunologia , Autoanticorpos/imunologia
7.
J Neuromuscul Dis ; 11(3): 613-623, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38578899

RESUMO

Background/Objective: Myasthenia Gravis (MG) is an autoimmune disorder characterized by pathogenic autoantibodies (AAbs) targeting nicotinic acetylcholine receptors (AChR), disrupting neuromuscular communication. RadioImmunoPrecipitation Assay (RIPA) is recommended to detect AChR AAbs, but its complexity and radioactive requirements limit widespread use. We compare non-RIPA anti-AChR immunoassays, including Cell-Based Assay (CBA) and two ELISA kits, against the gold standard RIPA. Methods/Results: 145 samples were included with medical indication for anti-AChR testing. By the RIPA method, 63 were negative (RIPA-Neg < 0.02 nmol/L), 18 were classified as Borderline (≥0.02 -1 nmol/L), and 64 were positive (RIPA-Pos > 1 nmol/L). The competitive ELISA showed poor agreement with RIPA (Kappa = 0.216). The indirect ELISA demonstrated substantial agreement with RIPA (Kappa = 0.652), with ∼76% sensitivity and ∼94% specificity for MG diagnostic. The CBA, where fixed cells expressing clustered AChR were used as substrate, exhibited almost perfect agreement with RIPA (Kappa = 0.984), yielding ∼98% sensitivity and 96% specificity for MG. In addition, a semiquantitative analysis showed a strong correlation between CBA titration, indirect ELISA, and RIPA levels (r = 0.793 and r = 0.789, respectively). Conclusions: The CBA displayed excellent analytical performance for MG diagnostic when compared to RIPA, making it a potential replacement for RIPA in clinical laboratories. Some solid-phase assays (such as the indirect ELISA applied here), as well as CBA titration, offer reliable options to estimate anti-AChR AAb levels after confirming positivity by the CBA.∥.


Assuntos
Autoanticorpos , Ensaio de Imunoadsorção Enzimática , Miastenia Gravis , Ensaio de Radioimunoprecipitação , Humanos , Ensaio de Imunoadsorção Enzimática/métodos , Miastenia Gravis/imunologia , Miastenia Gravis/diagnóstico , Sensibilidade e Especificidade , Receptores Colinérgicos/imunologia , Feminino , Masculino , Pessoa de Meia-Idade , Adulto , Idoso , Adulto Jovem
8.
Rev Med Suisse ; 20(871): 848-851, 2024 Apr 24.
Artigo em Francês | MEDLINE | ID: mdl-38665106

RESUMO

Myasthenia gravis (MG) is an autoimmune disease characterized by fluctuating weakness of skeletal muscles. Despite current treatments, a significant percentage of patients remain symptomatic. This review explores new immunosuppressive therapies and ongoing clinical trials in MG, including depletion of B lymphocytes with agents such as rituximab and inebilizumab, as well as the use of eculizumab, efgartigimod, satralizumab, tocilizumab, and CAR-T (Chimeric Antigen Receptor-T) cell therapy. These advancements aim to improve disease control and patients' quality of life.


La myasthénie grave (MG) est une maladie auto-immune caractérisée par une faiblesse fluctuante des muscles squelettiques. Malgré les traitements classiques, un pourcentage significatif de patients reste symptomatique. Cet article explore les nouvelles thérapies immunosuppressives et les essais cliniques en cours pour la MG, notamment la déplétion des lymphocytes B avec des agents tels que le rituximab et l'inébilizumab, ainsi que l'utilisation de l'éculizumab, de l'efgartigimod, du satralizumab, du tocilizumab et de la thérapie par cellules CAR-T (Chimeric Antigen Receptor-T). Ces avancées visent à améliorer le contrôle de la maladie et la qualité de vie des patients.


Assuntos
Miastenia Gravis , Miastenia Gravis/imunologia , Miastenia Gravis/terapia , Miastenia Gravis/tratamento farmacológico , Humanos , Imunossupressores/uso terapêutico , Qualidade de Vida , Agentes de Imunomodulação/uso terapêutico , Linfócitos B/imunologia , Linfócitos B/efeitos dos fármacos , Fatores Imunológicos/uso terapêutico
9.
Rinsho Shinkeigaku ; 64(4): 292-295, 2024 Apr 24.
Artigo em Japonês | MEDLINE | ID: mdl-38508730

RESUMO

A 79-year-old woman who presented ptosis and dysphagia were admitted to our hospital. Anti-acetylcholine receptor antibodies and anti-P/Q-type VGCC antibodies were both positive. Electrophysiological examination showed postsynaptic pattern which supported myasthenia gravis. She did not meet the diagnostic criteria for Lambert-Eaton myasthenic syndrome (LEMS). In cases which these antibodies coexist, careful electrophysiological evaluation is required for the diagnosis. In addition, although anti-P/Q-type VGCC antibodies have been specific to LEMS, patients with these antibodies represent various symptoms other than LEMS. Low and middle titer of the antibodies may be not specific to LEMS.


Assuntos
Autoanticorpos , Miastenia Gravis , Receptores Colinérgicos , Humanos , Feminino , Miastenia Gravis/imunologia , Miastenia Gravis/diagnóstico , Miastenia Gravis/complicações , Idoso , Autoanticorpos/sangue , Receptores Colinérgicos/imunologia , Canais de Cálcio Tipo Q/imunologia , Canais de Cálcio Tipo P/imunologia , Síndrome Miastênica de Lambert-Eaton/imunologia , Síndrome Miastênica de Lambert-Eaton/diagnóstico , Síndrome Miastênica de Lambert-Eaton/complicações
10.
Expert Opin Pharmacother ; 25(4): 395-408, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38523508

RESUMO

INTRODUCTION: Myasthenia gravis (MG) is an autoimmune condition targeting the neuromuscular junction, which manifests with neuromuscular symptoms of varying severity and significant morbidity. The mainstay of treatment in MG is mitigation of the immune cascade with steroids and non-steroidal immunosuppressive therapies. The therapeutic strategies in MG are transitioning from broad and indiscriminate immunosuppression to novel agents targeting key steps in MG pathogenesis, including T cell activation, B cell proliferation, complement activation, maintenance of pathogenic antibody production, and proinflammatory cytokine production. AREAS COVERED: In this review, an overview of the pathogenesis of MG and traditional MG therapies is presented, followed by a discussion of the novel MG drugs that have been evaluated in phase 3 clinical trials with an emphasis on those which have received regulatory approval. EXPERT OPINION: Novel MG therapeutics belonging to the classes of complement inhibitors, neonatal Fc receptor (FcRn) inhibitors and B cell depletors, as well as the other emerging MG drugs in the pipeline constitute promising treatment strategies with potentially better efficacy and safety compared to the conventional MG treatments. However, further long-term research is needed in order to optimize the implementation of these new treatment options for the appropriate patient populations.


Assuntos
Imunossupressores , Miastenia Gravis , Humanos , Miastenia Gravis/tratamento farmacológico , Miastenia Gravis/imunologia , Miastenia Gravis/terapia , Imunossupressores/uso terapêutico , Animais , Linfócitos B/imunologia , Linfócitos B/efeitos dos fármacos , Inativadores do Complemento/uso terapêutico , Inativadores do Complemento/farmacologia
11.
Neurol Sci ; 44(10): 3707-3709, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37306795

RESUMO

INTRODUCTION: Myasthenia gravis is a long-lasting autoimmune neuromuscular disease caused by antibodies attacking the neuromuscular junction, which can result in muscle weakness, fatigue, and respiratory failure in severe cases. Myasthenic crisis is a life-threatening event that requires hospitalization and treatments with intravenous immunoglobulin or plasma exchange. We reported the case of an AChR-Ab-positive myasthenia gravis patient with refractory myasthenic crisis, in which starting eculizumab as rescue therapy led to a complete resolution of the acute neuromuscular condition. CASE PRESENTATION: A 74-year-old man diagnosed with myasthenia gravis. ACh-receptor antibodies positivity comes to our observation for a recrudescence of symptoms, unresponsive to conventional rescue therapies. Due to the clinical worsening over the following weeks, the patient was admitted to intensive care unit, where he underwent therapy with eculizumab. About 5 days after the treatment, there was a significant and complete recovery of clinical condition with weaning-off from invasive ventilation and discharge to outpatient regimen, with reduction of steroid intake and biweekly maintenance with eculizumab. DISCUSSION: Eculizumab, a humanized monoclonal antibody that inhibits complement activation, is now approved as treatment for refractory generalized myasthenia gravis with anti-AChR antibodies. The use of eculizumab in myasthenic crisis is still investigational, but this case report suggests that it may be a promising treatment option for patients with severe clinical condition. Ongoing clinical trials will be needed to further evaluate the safety and efficacy of eculizumab in myasthenic crisis.


Assuntos
Anticorpos Monoclonais Humanizados , Inativadores do Complemento , Miastenia Gravis , Receptores Colinérgicos , Humanos , Masculino , Idoso , Miastenia Gravis/imunologia , Miastenia Gravis/terapia , Anticorpos Monoclonais Humanizados/uso terapêutico , Inativadores do Complemento/uso terapêutico , Receptores Colinérgicos/imunologia , Autoanticorpos/sangue
12.
Eur J Neurol ; 30(5): 1409-1416, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36752022

RESUMO

BACKGROUND AND PURPOSE: Complement component 5 (C5) targeting therapies are clinically beneficial in patients with acetylcholine receptor antibody+ (AChR-Ab+ ) generalized myasthenia gravis (MG). That clearly implicates antibody-mediated complement activation in MG pathogenesis. Here, classical and alternative complement pathways were profiled in patients from different MG subgroups. METHODS: In a case-control study, concentrations of C3a, C5a and sC5b9 were simultaneously quantified, indicating general activation of the complement system, whether via the classical and lectin pathways (C4a) or the alternative pathway (factors Ba and Bb) in MG patients with AChR or muscle-specific kinase antibodies (MuSK-Abs) or seronegative MG compared to healthy donors. RESULTS: Treatment-naïve patients with AChR-Ab+ MG showed substantially increased plasma levels of cleaved complement components, indicating activation of the classical and alternative as well as the terminal complement pathways. These increases were still present in a validation cohort of AChR-Ab+ patients under standard immunosuppressive therapies; notably, they were not evident in patients with MuSK-Abs or seronegative MG. Neither clinical severity parameters (at the time of sampling or 1 year later) nor anti-AChR titres correlated significantly with activated complement levels. CONCLUSIONS: Markers indicative of complement activation are prominently increased in patients with AChR-Ab MG despite standard immunosuppressive therapies. Complement inhibition proximal to C5 cleavage should be explored for its potential therapeutic benefits in AChR-Ab+ MG.


Assuntos
Autoanticorpos , Ativação do Complemento , Miastenia Gravis , Receptores Colinérgicos , Humanos , Autoanticorpos/imunologia , Estudos de Casos e Controles , Ativação do Complemento/imunologia , Proteínas do Sistema Complemento/análise , Proteínas do Sistema Complemento/imunologia , Miastenia Gravis/classificação , Miastenia Gravis/tratamento farmacológico , Miastenia Gravis/imunologia , Receptores Colinérgicos/imunologia , Via Alternativa do Complemento , Via Clássica do Complemento , Masculino , Feminino , Adulto Jovem , Adulto , Pessoa de Meia-Idade
13.
Isr Med Assoc J ; 24(1): 9-10, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35077038
14.
Ann Clin Transl Neurol ; 9(2): 122-131, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35080153

RESUMO

OBJECTIVE: To describe the clinical characteristics and outcomes in patients with refractory myasthenia gravis (MG) and to determine the effectiveness and side effects of the drugs used for their treatment. METHODS: This observational retrospective cross-sectional multicenter study was based on data from the Spanish MG Registry (NMD-ES). Patients were considered refractory when their MG Foundation of America post-interventional status (MGFA-PIS) was unchanged or worse after corticosteroids and two or more other immunosuppressive agents. Clinical and immunologic characteristics of drug-refractory patients, efficiency and toxicity of drugs used, and outcome (MGFA-PIS) at end of follow-up were studied. RESULTS: We included 990 patients from 15 hospitals. Eighty-four patients (68 of 842 anti-acetylcholine receptor [AChR], 5 of 26 anti-muscle-specific tyrosine kinase [MusK], 10 of 120 seronegative, and 1 of 2 double-seropositive patients) were drug refractory. Drug-refractory patients were more frequently women (p < 0.0001), younger at onset (p < 0.0001), and anti-MuSK positive (p = 0.037). Moreover, they more frequently presented a generalized form of the disease, bulbar symptoms, and life-threatening events (p < 0.0001; p = 0.018; and p = 0.002, respectively) than non-drug-refractory patients. Mean follow-up was 9.8 years (SD 4.5). Twenty-four (50%) refractory patients had side effects to one or more of the drugs. At the end of follow-up, 42.9% of drug-refractory patients (42.6% of anti-AChR, 100% of anti-MuSK, and 10% of seronegative patients) and 79.8% of non-drug-refractory patients (p < 0.0001) achieved remission or had minimal manifestations. Eighty percent of drug-refractory-seronegative patients did not respond to any drug tested. INTERPRETATION: In this study, 8.5% of MG patients were drug-refractory. New more specific drugs are needed to treat drug-refractory MG patients.


Assuntos
Fatores Imunológicos/farmacologia , Miastenia Gravis/diagnóstico , Miastenia Gravis/tratamento farmacológico , Miastenia Gravis/imunologia , Sistema de Registros , Adulto , Idoso , Estudos Transversais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Estudos Retrospectivos , Espanha
15.
Lancet Neurol ; 21(2): 189-202, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-35065041

RESUMO

Myasthenia gravis and Lambert-Eaton myasthenic syndrome are antibody-mediated autoimmune diseases of the neuromuscular junction that usually present with weakness in ocular muscles and in proximal muscles of the limb and trunk. Prognosis regarding muscle strength, functional abilities, quality of life, and survival is generally good. However, some patients do not respond to treatment. Symptomatic drugs, corticosteroids, and steroid-sparing immunosuppressive drugs remain the cornerstone of treatment. In the past few years, new biological agents against complement, the FcRn receptor, or B-cell antigens have been tested in clinical trials. These new therapies extend the possibilities for targeted immunotherapies and promise exciting new options with a relatively rapid mode of action. Challenges in their use might occur, with barriers due to an increase in cost of care and additional considerations in the choice of drugs, and potential consequences of infection and vaccination due to the COVID-19 pandemic.


Assuntos
Doenças Autoimunes , Doenças da Junção Neuromuscular , Doenças Autoimunes/terapia , Humanos , Síndrome Miastênica de Lambert-Eaton/imunologia , Síndrome Miastênica de Lambert-Eaton/terapia , Miastenia Gravis/imunologia , Miastenia Gravis/terapia , Doenças da Junção Neuromuscular/imunologia , Doenças da Junção Neuromuscular/terapia
16.
J Neuroimmune Pharmacol ; 17(3-4): 437-452, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-34716498

RESUMO

Emerging data have revealed that CD95 can evoke non-apoptotic signals, thereby promoting pro-inflammatory functions that link to the severity of autoimmune disorders. Here, we reported that the expression of CD95 in CD4+ effector memory T (CD4+ TEM) cells was increased in myasthenia gravis (MG) patients. We also found increased expression of CD95 in CD4+ TEM cells from MG patients correlated positively with clinical severity scores (QMGs), serum IL-17 levels and plasma cells (PCs) frequencies. Conventional treatment, such as glucocorticoid, could down-regulate the expression of CD95 in CD4+ TEM cells, QMGs, serum IL-17 levels and PCs frequencies from MG patients. In vitro, low-dose of agonistic anti-CD95 mAb could promote Th17 cell development. This effect was reversed by CD95 siRNA. Moverover, CD95 stimulation induced the phosphorylation of p38 and Erk1/2 and Th17 cell differentiation, and p38 specific inhibitor SB203580 or Erk1/2 specific inhibitor PD98059 could induce opposite changes. However, SB203580 or PD98059 do not abrogate the increase of CCR6+IL-17A+ cells, ROR-γt and IL-17 expression induced by CD95 triggering relatively to each corresponding control. This suggests that p38 and Erk1/2 MAPK pathway plays a role in expression of CCR6+IL-17A+ cells, ROR-γt and IL-17, but not in their increase induced by CD95 triggering. Taken together, this study revealed that increased expression of CD95 in CD4+ TEM cells promotes Th17 response under the microenvironment of MG.


Assuntos
Células T de Memória , Miastenia Gravis , Células Th17 , Humanos , Interleucina-17/sangue , Células T de Memória/imunologia , Miastenia Gravis/imunologia , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Células Th17/imunologia
17.
Scand J Immunol ; 95(2): e13122, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34796975

RESUMO

Immunoadsorption apheresis (IA) or intravenous immunoglobulin (IVIg) is used to treat exacerbation of myasthenia gravis (MG). This study aimed to compare the efficacy and safety between IA and IVIg for MG patients with anti-acetylcholine receptor (AChR) antibodies. We retrospectively studied 19 AChR antibody-positive generalized MG patients who underwent IA (n = 9) or IVIg treatment (n = 10). We reviewed the MG activities of daily living profile (MG-ADL) scores at baseline, 1 and 3 months after the treatment. Adverse events during the treatment period were also reviewed. The MG-ADL scores showed significantly greater improvement from the baseline in the IA group than in the IVIg group (1 month: -7 vs -3, P = .035; 3 months -9 vs -2.5, P = .016). An adverse event that led to the discontinuation of the treatment was observed in only one patient in the IVIg group (anaphylactic reaction). Our data suggest that the IA treatment is safe and more efficacious than the IVIg treatment for aggravation of anti-AChR-positive MG. Larger prospective studies are required to confirm the finding.


Assuntos
Autoanticorpos/sangue , Remoção de Componentes Sanguíneos/métodos , Imunoglobulinas Intravenosas/uso terapêutico , Miastenia Gravis/terapia , Autoanticorpos/imunologia , Remoção de Componentes Sanguíneos/efeitos adversos , Feminino , Humanos , Imunoglobulinas Intravenosas/efeitos adversos , Masculino , Pessoa de Meia-Idade , Miastenia Gravis/imunologia , Receptores Colinérgicos/imunologia , Estudos Retrospectivos
18.
Front Immunol ; 12: 753247, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34956185

RESUMO

This study aimed to establish a cell-based assay (CBA) for the detection of agrin antibodies (Agrin-Ab) to explore the clinical features of agrin antibody-positive Chinese patients with myasthenia gravis (Agrin-MG). We developed a CBA based on the human full-length agrin protein expressed in HEK293T cells for the reliable and efficient detection of Agrin-Ab. Clinical data and serum samples were collected from 1948 MG patients in 26 provinces in China. The demographic and clinical features of Agrin-MG patients were compared with those of other MG patient subsets. Eighteen Agrin-MG cases were identified from 1948 MG patients. Nine patients were Agrin-Ab positive, and nine were AChR-Ab and Agrin-Ab double-positive (Agrin/AChR-MG). Eleven (61.11%) patients were males older than 40 years of age. The initial symptom in 13 (81.25%) cases was ocular weakness. Occasionally, the initial symptom was limb-girdle weakness (two cases) or bulbar muscle weakness (one case). Agrin-MG patients demonstrated slight improvement following treatment with either acetylcholinesterase inhibitor or prednisone; however, the combination of the two drugs could effectively relieve MG symptoms. In China, Agrin-MG demonstrated seropositivity rates of 0.92%. These patients were commonly middle-aged or elderly men. The patients usually presented weakness in the ocular, bulbar, and limb muscles, which may be combined with thymoma. These patients have more severe diseases, although the combination of pyridostigmine and prednisone was usually effective in relieving symptoms.


Assuntos
Agrina/imunologia , Autoanticorpos/sangue , Autoantígenos/imunologia , Miastenia Gravis/imunologia , Prednisona , Idade de Início , Idoso , Agrina/química , Agrina/genética , Autoantígenos/química , Autoantígenos/genética , China/epidemiologia , Inibidores da Colinesterase/uso terapêutico , Feminino , Geografia Médica , Células HEK293 , Humanos , Masculino , Pessoa de Meia-Idade , Debilidade Muscular/etiologia , Miastenia Gravis/etnologia , Miastenia Gravis/etiologia , Prednisona/uso terapêutico , Proteínas Recombinantes/imunologia , Timoma/complicações , Neoplasias do Timo/complicações
19.
Front Immunol ; 12: 788499, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34956219

RESUMO

Immune checkpoint inhibitors (ICIs) and radiotherapy (RT) combinations for various metastatic cancers are increasingly utilized, yet the augmentation of anti-cancer immunity including distant tumor responses by RT remains ill-characterized. Immunosuppressive tumor microenvironments and defective anti-tumor immune activation including immune-related adverse events (irAEs) likely limit dramatic immuno-radiotherapy combinations, though it remains unclear which immune characteristics mediate dramatic systemic tumor regression in only a small subset of patients. Moreover, the efficacy of ICI treatment in patients receiving immunosuppressive therapies for autoimmune conditions or irAEs is convoluted, yet clinically valuable. Here, we report a case of a 75-year-old man with myasthenia gravis and metastatic melanoma who experienced complete and durable systemic regression after receiving pembrolizumab and single-lesion RT while on prednisone for myasthenia gravis prophylaxis and vedolizumab for immune-mediated colitis after previously experiencing mixed response on pembrolizumab monotherapy. We discuss the potential paradoxical effects and clinical considerations of immunosuppressive regimens in patients with underlying autoimmune disease or adverse immune reactions while receiving immuno-radiotherapy combinations.


Assuntos
Anticorpos Monoclonais Humanizados/uso terapêutico , Quimiorradioterapia , Colite/tratamento farmacológico , Inibidores de Checkpoint Imunológico/uso terapêutico , Imunossupressores/uso terapêutico , Melanoma/terapia , Miastenia Gravis/tratamento farmacológico , Prednisona/uso terapêutico , Neoplasias Cutâneas/terapia , Idoso , Anticorpos Monoclonais Humanizados/efeitos adversos , Quimiorradioterapia/efeitos adversos , Colite/induzido quimicamente , Colite/diagnóstico , Colite/imunologia , Humanos , Inibidores de Checkpoint Imunológico/efeitos adversos , Hospedeiro Imunocomprometido , Masculino , Melanoma/imunologia , Melanoma/secundário , Miastenia Gravis/diagnóstico , Miastenia Gravis/imunologia , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/patologia , Resultado do Tratamento
20.
Medicine (Baltimore) ; 100(44): e27688, 2021 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-34871253

RESUMO

ABSTRACT: Ocular myasthenia gravis (MG) is the mainly widespread type of MG among juveniles. Buzhong Yiqi decoction (BZ) is a well-known traditional Chinese medicine prescription for treating MG. It has rarely been discussed whether the concentration of anti-acetylcholine receptor (AChR) antibodies is related to the clinical status of juvenile ocular myasthenia gravis (JOMG) treated with BZ.The patients with JOMG who had more than once AChR-antibody (ab) test and treated with BZ were retrospectively identified from June 2013 to January 2020 in the first hospital in Shijiazhuang. The presence or absence of ocular symptoms was used to grade the effectiveness of treatment. Generalized estimating equations logistic regression analysis was used to evaluate the effect of AChR ab concentration on the clinical status of MG.A total of 549 AChR-ab tests were performed in 135 patients, and the corresponding clinical status was recorded. One hundred two patients received treatment with BZ only and 33 combined with immunosuppressive drugs. In the group receiving only BZ treatment, the anti-acetylcholine receptor ab concentration was positively correlated with the clinical score after treatment.The results suggest that BZ could affect the AChR-ab. Repeated AChR-ab assays can provide information about the clinical status. For JOMG patients who only receive Buzhong Yiqi Decoction treatment, this can support treatment decisions.


Assuntos
Autoanticorpos/sangue , Medicamentos de Ervas Chinesas/uso terapêutico , Imunossupressores/uso terapêutico , Medicina Tradicional Chinesa/métodos , Miastenia Gravis/tratamento farmacológico , Receptores Colinérgicos/sangue , Biomarcadores/sangue , Pré-Escolar , Feminino , Humanos , Masculino , Miastenia Gravis/sangue , Miastenia Gravis/imunologia , Receptores Colinérgicos/imunologia , Estudos Retrospectivos , Resultado do Tratamento
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