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Sample records for autoimmune myasthenia gravis

  1. Autoimmune myasthenia gravis.

    PubMed

    Jayawant, Sandeep; Parr, Jeremy; Vincent, Angela

    2013-01-01

    Myasthenia gravis in children can be generalized or ocular, and associated with antibodies to acetylcholine receptors or muscle-specific kinase, but it can be negative for those antibodies (seronegative). It needs to be distinguished from congenital myasthenic syndromes and other neuromuscular diseases. In the perinatal period, transient neonatal myasthenia and arthrogryposis multiplex congenita, due to maternal antibodies, need to be considered. Juvenile myasthenia is similar in presentation and treatment to that in adults. Here we present guidelines for recognition, diagnosis, and treatment. PMID:23622368

  2. Myasthenia Gravis

    MedlinePlus

    Myasthenia gravis is a disease that causes weakness in the muscles under your control. It happens because ... problem in communication between your nerves and muscles. Myasthenia gravis is an autoimmune disease. Your body's own ...

  3. Autoimmune myasthenia gravis, immunotherapy and thymectomy in children.

    PubMed

    Ware, Tyson L; Ryan, Monique M; Kornberg, Andrew J

    2012-02-01

    Autoimmune myasthenia gravis is a rare condition in children. Identifying antibodies directed against the acetylcholine receptor is helpful in making the diagnosis. However, seronegative cases do exist and need to be distinguished from congenital forms of myasthenia. There is little published experience to inform the judicious management of autoimmune myasthenia gravis in children. In this article, we report our experience in the management of 12 cases of autoimmune myasthenia gravis in children in the modern era of medical immunotherapy and thymectomy. PMID:21911294

  4. [Myasthenia gravis].

    PubMed

    Schodrowski, J; Seipelt, M; Adibi-Sedeh, I; Eienbröker, C; Tackenberg, B

    2016-04-01

    Myasthenia gravis is an autoimmune disease, which leads to load-dependent weakness of voluntary skeletal muscles with recovery of function after resting. The disease is caused by autoantibodies directed against the postsynaptic nicotinic acetylcholine receptors (AChR) leading to a reduction of neuromuscular transmission. Muscles and nerves are not affected. Disorders of the thymus play a role in the pathogenesis of AChR antibody-positive myasthenia. The clinical symptoms include exercise-induced fatigue either of the ocular muscles alone (ocular myasthenia) or striated skeletal muscle and the ocular, facial and bulbar musculature (generalized myasthenia). Treatment of myasthenia gravis involves administration of acetylcholine esterase inhibitors and immunosuppressive drugs. A myasthenic crisis is characterized by life-threatening complications with severe weakness, swallowing difficulties and respiratory failure, which requires intensive care treatment. PMID:27000188

  5. Complicating autoimmune diseases in myasthenia gravis: a review

    PubMed Central

    Nacu, Aliona; Andersen, Jintana Bunpan; Lisnic, Vitalie; Owe, Jone Furlund; Gilhus, Nils Erik

    2015-01-01

    Abstract Myasthenia gravis (MG) is a rare autoimmune disease of skeletal muscle endplates. MG subgroup is relevant for comorbidity, but usually not accounted for. MG patients have an increased risk for complicating autoimmune diseases, most commonly autoimmune thyroid disease, systemic lupus erythematosus and rheumatoid arthritis. In this review, we present concomitant autoimmune disorders associated with the different MG subgroups, and show how this influences treatment and prognosis. Concomitant MG should always be considered in patients with an autoimmune disorder and developing new neuromuscular weakness, fatigue or respiratory failure. When a second autoimmune disorder is suspected, MG should be included as a differential diagnosis. PMID:25915571

  6. Myasthenia gravis, a model of organ-specific autoimmune disease.

    PubMed

    Berrih-Aknin, S

    1995-04-01

    Myasthenia gravis (MG) is a neuromuscular disorder of autoimmune origin. Most patients have antibodies directed against the acetylcholine receptor (AChR) that interfere with neuromuscular transmission. MG is a model of organ-specific autoimmune disease in which the autoantigen, AChR, is well characterized. However, several questions remain unanswered. Why is AChR, which is present in the thymus, not tolerized? Why does the anti-AChR antibody titre not correlate with clinical manifestations, and why do some patients not have such antibodies? What genetic elements are involved in disease susceptibility? How is the expression of AChR regulated after its attack by autoantibodies? Could MG patients benefit from new immunomodulatory treatments? At the IVth EuroMyasthenia meeting, held in Versailles in April 1994, almost 200 researchers and physicians met to discuss the pathophysiology and treatment of myasthenia gravis and to provide answers to some of these questions. The sessions covered immunological, genetic and clinical aspects of MG. PMID:7612144

  7. Treatment of passively transferred experimental autoimmune myasthenia gravis using papain

    PubMed Central

    Poulas, K; Tsouloufis, T; Tzartos, S J

    2000-01-01

    Antibody-mediated acetylcholine receptor (AChR) loss at the neuromuscular junction, the main cause of the symptoms of myasthenia gravis, is induced by bivalent or multivalent antibodies. Passive transfer of experimental autoimmune myasthenia gravis (EAMG) can be induced very efficiently in rats by administration of intact MoAbs directed against the main immunogenic region (MIR) of the AChR, but not by their monovalent Fab fragments. We tested whether papain, which has been used therapeutically in autoimmune and other diseases, is capable of preventing EAMG by in vivo cleavage of the circulating anti-AChR antibodies into Fab fragments. EAMG was induced in 4-week-old female Lewis rats by i.p. injection of anti-MIR mAb35. A total of 0·75 mg of papain was given as one or three injections 3–7 h after MoAb injection. The mAb35 + papain-treated animals developed mild weakness during the first 30 h and subsequently recovered, while all animals that received only mAb35 developed severe myasthenic symptoms and died within 24–30 h. Animals treated only with papain showed no apparent side effects for up to 2 months. Serum anti-AChR levels in mAb35 + papain-treated rats decreased within a few hours, whereas in non-papain-treated rats they remained high for at least 30 h. Muscle AChR in mAb35 + papain-treated animals was partially protected from antibody-mediated degradation. These results show that treatment of rats with papain can prevent passively transferred EAMG without any apparent harm to the animals, and suggest a potential therapeutic use for proteolytic enzymes in myasthenia gravis. PMID:10792389

  8. Myasthenia gravis - resources

    MedlinePlus

    Resources - myasthenia gravis ... The following organizations provide information on myasthenia gravis : Myasthenia Gravis Foundation of America -- www.myasthenia.org National Institute of Neurological Disorders and Stroke -- www.ninds.nih.gov/disorders/myasthenia_ ...

  9. Strategies for Treating Autoimmunity Novel Insights from Experimental Myasthenia Gravis

    PubMed Central

    Meriggioli, Matthew N.; Sheng, Jiarong; Li, Liangcheng; Prabhakar, Bellur S.

    2009-01-01

    Current treatments for myasthenia gravis (MG) rely upon the administration of immunosuppressive agents which result in global, nonspecific attenuation of the immune response. An alternative approach would be to attempt to design therapies that specifically dampen autoreactivity without affecting general immunity. Recently, dendritic cells (DCs) have been shown to possess potent capabilities to tolerize T cells in an antigen-specific manner. We have observed that the selective activation of particular subsets of DCs utilizing granulocyte-macrophage colony-stimulating factor (GM-CSF) had profound effects on the induction of experimental autoimmune myasthenia gravis (EAMG). Specifically, treatment with GM-CSF effectively suppressed the induction of EAMG and down-modulated anti-AChR T cell and pathogenic antibody responses. These effects were associated with the activation of tolerogenic DCs, the enhanced production of suppressive cytokines, such as IL-10, and the mobilization of.CD4+ CD2S+ and FoxP3+ regulatory T cells (Tregs). We have further shown that GM-CSF effectively ameliorates clinical disease severity in mice with active, ongoing EAMG. Based on these observations, we hypothesize that the selective activation of particular DC subsets in vivo using pharmacologic agents, like GM-CSF, can suppress ongoing anti-AChR immune responses by mobilizing antigen-specific Tregs capable of suppressing autoimmune MG. PMID:18567878

  10. Curcumin ameliorates experimental autoimmune myasthenia gravis by diverse immune cells.

    PubMed

    Wang, Shan; Li, Heng; Zhang, Min; Yue, Long-Tao; Wang, Cong-Cong; Zhang, Peng; Liu, Ying; Duan, Rui-Sheng

    2016-07-28

    Curcumin is a traditional Asian medicine with diverse immunomodulatory properties used therapeutically in the treatment of many autoimmune diseases. However, the effects of curcumin on myasthenia gravis (MG) remain undefined. Here we investigated the effects and potential mechanisms of curcumin in experimental autoimmune myasthenia gravis (EAMG). Our results demonstrated that curcumin ameliorated the clinical scores of EAMG, suppressed the expression of T cell co-stimulatory molecules (CD80 and CD86) and MHC class II, down-regulated the levels of pro-inflammatory cytokines (IL-17, IFN-γ and TNF-α) and up-regulated the levels of the anti-inflammatory cytokine IL-10, shifted the balance from Th1/Th17 toward Th2/Treg, and increased the numbers of NKR-P1(+) cells (natural killer cell receptor protein 1 positive cells, including NK and NKT cells). Moreover, the administration of curcumin promoted the differentiation of B cells into a subset of B10 cells, increased the anti-R97-166 peptide IgG1 levels and decreased the relative affinity indexes of anti-R97-116 peptide IgG. In summary, curcumin effectively ameliorate EAMG, indicating that curcumin may be a potential candidate therapeutic agent for MG. PMID:27181511

  11. Combined short-term immunotherapy for experimental autoimmune myasthenia gravis

    SciTech Connect

    Pestronk, A.; Drachman, D.B.; Teoh, R.; Adams, R.N.

    1983-08-01

    A therapeutic strategy was designed to eliminate the humoral immune response to acetylcholine receptor (AChR) in ongoing experimental autoimmune myasthenia gravis (EAMG). Rats with EAMG were treated with a protocol consisting of three components: (1) A single high dose of cyclophosphamide (200 mg/kg) was used to produce a rapid and sustained fall in the anti-AChR antibody levels by preferential destruction of antibody-producing B-lymphocytes. ''Memory'' lymphocytes were not eliminated by cyclophosphamide. (2) Irradiation (600 rads) was used to eliminate the ''memory'' cells. It eliminated the anamnestic response to a challenge with the antigen AChR. (3) Bone marrow transplantation was used to repopulate the hematopoietic system after the otherwise lethal dose of cyclophosphamide. We used bone marrow from syngeneic rats with active EAMG to simulate an autologous transplant. Rats with EAMG treated with this combined protocol showed a prompt and sustained fall in the anti-AChR antibody levels and had no anamnestic response to a challenge with AChR. Thus, an affected animal's own marrow could be stored and used later for repopulation after cyclophosphamide-irradiation treatment. This treatment eliminates the animal's ongoing immune responses and reconstitutes the immune system in its original state. The success of this approach suggests that, if their safety could be established, similar ''curative'' strategies might be developed for the treatment of patients with severe antibody-mediated autoimmune disorders, such as myasthenia gravis.

  12. Myasthenia Gravis

    MedlinePlus

    ... Funding Information Research Programs Training & Career Awards Enhancing Diversity Find People About NINDS NINDS Myasthenia Gravis Information ... News From NINDS | Find People | Training | Research | Enhancing Diversity Careers@NINDS | FOIA | Accessibility Policy | Contact Us | Privacy ...

  13. Autoimmune myasthenia gravis and dysautonomia in a dog.

    PubMed

    Gajanayake, I; Niessen, S J M; Cherubini, G B; Shelton, G D

    2008-11-01

    A two-year-old male entire border collie dog was evaluated for a short history of mixed bowel diarrhoea, coughing, vomiting and stranguria. Physical examination revealed dyspnoea with increased ventral lung sounds and a flaccidly distended bladder. Neurological examination revealed poor pupillary light reflexes, an absent gag reflex and a poor anal tone. Thoracic radiography was consistent with megaoesophagus and aspiration pneumonia. Clinicopathological testing revealed an elevated muscular nicotinic acetylcholine receptor antibody titre. The dog was euthanased because of clinical deterioration. Cerebrospinal fluid (CSF) collected immediately post-mortem revealed macrophagic pleocytosis. Post-mortem histopathological examination was consistent with dysautonomia. This is the first report of coexisting autoimmune myasthenia gravis and dysautonomia in a non-human species. The concomitant diseases may suggest a common immunopathological aetiology. PMID:18684149

  14. Vaccines against myasthenia gravis

    PubMed Central

    Berrih-Aknin, Sonia; Fuchs, Sara; Souroujon, Miriam C

    2007-01-01

    Myasthenia gravis (MG) is an autoimmune disease mediated by antibodies to nicotinic acetylcholine receptor (AChR) interfering with the neuromuscular transmission. Experimental autoimmune MG serves as an excellent animal model to study possible therapeutic modalities for MG. This review will focus on the different ways to turn off the autoimmune response to AChR, which results in suppression of myasthenia. This paper will describe the use of fragments or peptides derived from the AChR, antigen-presenting cells and anti-T cell receptor antibodies, and will discuss the underlying mechanisms of action. Finally, the authors propose new promising therapeutic prospects, including treatment based on the modulation of regulatory T cells, which have recently been found to be functionally defective in MG patients. PMID:16018742

  15. Myasthenia Gravis Foundation of America

    MedlinePlus

    ... Gravis (gMG). In the study, the primary efficacy endpoint of change from baseline in Myasthenia Gravis Activities ... significance. However, the first prospectively defined secondary efficacy endpoint of change from baseline in Quantitative Myasthenia Gravis ( ...

  16. The role of antibodies in myasthenia gravis.

    PubMed

    De Baets, M; Stassen, M H W

    2002-10-15

    Myasthenia gravis is an autoimmune disease associated with antibodies directed to the postsynaptic acetylcholine receptor. These antibodies reduce the number of receptors. Autoantibodies against AChR and other muscle antigens can be used for the diagnosis of myasthenia gravis and related disorders. The origin and the role of these antibodies in the disease are discussed. Experimental autoimmune myasthenia gravis, an experimental model closely mimicking the disease, has provided answers to many questions about the role of antibodies, complement macrophages and AChR anchor proteins. Genetically modified anti-AChR antibodies may also be used in the future to treat myasthenia. PMID:12220686

  17. ROCK inhibitor abolishes the antibody response in experimental autoimmune myasthenia gravis.

    PubMed

    Li, Heng; Zhang, Min; Wang, Cong-Cong; Li, Xiao-Li; Zhang, Peng; Yue, Long-Tao; Miao, Shuai; Dou, Ying-Chun; Li, Yan-Bin; Duan, Rui-Sheng

    2016-07-01

    The Rho/Rho kinase (ROCK) pathway serves as molecular switches in many biological processes including the immune response. ROCK inhibitors lead to amelioration of some autoimmune diseases. The present study was designed to define whether a selective ROCK inhibitor, fasudil, was effective in experimental autoimmune myasthenia gravis (EAMG) and investigate the underlying mechanisms. Here we found fasudil effectively attenuated the development of ongoing EAMG. Fasudil abolished the antibody production and function by decreasing follicular helper T cells and CD19(+) B cells, especially germinal center B cells. Moreover, fasudil reduced the expression of CD80 on lymph node mononuclear cells. These findings suggest the inhibition of ROCK might be a potential therapeutic strategy for antibody-mediated autoimmune diseases. PMID:27168379

  18. Congenital myasthenia gravis.

    PubMed

    Nizamani, Noor Bakht; Talpur, Khalid Iqbal; Memon, Mariya Nazish

    2013-07-01

    Congenital myasthenia gravis is caused by genetic mutations affecting neuromuscular transmission, characterized by muscle weakness usually starting in childhood. A two and a half years old male child presented with bilateral ptosis and hoarseness of voice. The symptoms progressed giving the clinical impression of congenital myasthenia gravis. A series of tests were done including Ice Pack Test, acetylcholine receptor antibody test, trial of steroids and finally neostigmine test which confirmed the diagnosis. This case illustrates the challenges in diagnosing congenital myasthenia gravis and highlights the potential benefits of neostigmine test in its diagnosis. PMID:23823963

  19. Silencing miR-146a influences B cells and ameliorates experimental autoimmune myasthenia gravis

    PubMed Central

    Zhang, JunMei; Jia, Ge; Liu, Qun; Hu, Jue; Yan, Mei; Yang, BaiFeng; Yang, Huan; Zhou, WenBin; Li, Jing

    2015-01-01

    MicroRNAs have been shown to be important regulators of immune homeostasis as patients with aberrant microRNA expression appeared to be more susceptible to autoimmune diseases. We recently found that miR-146a was up-regulated in activated B cells in response to rat acetylcholine receptor (AChR) α-subunit 97-116 peptide, and this up-regulation was significantly attenuated by AntagomiR-146a. Our data also demonstrated that silencing miR-146a with its inhibitor AntagomiR-146a effectively ameliorated clinical myasthenic symptoms in mice with ongoing experimental autoimmune myasthenia gravis. Furthermore, multiple defects were observed after miR-146a was knocked down in B cells, including decreased anti-R97-116 antibody production and class switching, reduced numbers of plasma cells, memory B cells and B-1 cells, and weakened activation of B cells. Previously, miR-146a has been identified as a nuclear factor-κB-dependent gene and predicted to base pair with the tumour necrosis factor receptor-associated factor 6 (TRAF6) and interleukin-1 receptor-associated kinase 1 (IRAK1) genes to regulate the immune response. However, our study proved that miR-146a inhibition had no effect on the expression of TRAF6 and IRAK1 in B cells. This result suggests that the function of miR-146a in B cells does not involve these two target molecules. We conclude that silencing miR-146a exerts its therapeutic effects by influencing the B-cell functions that contribute to the autoimmune pathogenesis of myasthenia gravis. PMID:24962817

  20. Treatment for Myasthenia Gravis (MG)

    MedlinePlus

    ... are individualized There are many effective treatments for myasthenia gravis. Spontaneous improvement and even remission (although uncommon) ... Created by Kellen Interactive Web Design © copyright 2010 Myasthenia Gravis Foundation of America, Inc.

  1. IgG1 deficiency exacerbates experimental autoimmune myasthenia gravis in BALB/c mice

    PubMed Central

    Huda, Ruksana; Strait, Richard T.; Tüzün, Erdem; Finkelman, Fred D.; Christadoss, Premkumar

    2015-01-01

    Myasthenia gravis is an autoimmune disease characterized by muscle weakness due to neuromuscular junction (NMJ) damage by anti-acetylcholine receptor (AChR) auto-antibodies and complement. In experimental autoimmune myasthenia gravis (EAMG), which is induced by immunization with Torpedo AChR in CFA, anti-AChR IgG2b and IgG1 are the predominant isotypes in the circulation. Complement activation by isotypes such as IgG2b plays a crucial role in EAMG pathogenesis; this suggested the possibility that IgG1, which does not activate complement through the classical pathway, may suppress EAMG. In this study, we show that AChR-immunized BALB/c mice genetically deficient for IgG1 produce higher levels of complement-activating isotypes of anti-AChR, especially IgG3 and IgG2a, and develop increased IgG3/IgG2a deposits at the NMJ, as compared to wild type (WT) BALB/c mice. Consistent with this, AChR-immunized IgG1−/− BALB/c mice lose muscle strength and muscle AChR to a greater extent than AChR-immunized WT mice. These observations demonstrate that IgG1 deficiency leads to increased severity of EAMG associated with an increase in complement activating IgG isotypes. Further studies are needed to dissect the specific role or mechanism of IgG1 in limiting EAMG and that of EAMG exacerbating role of complement activating IgG3 and IgG2a in IgG1 deficiency. PMID:25867470

  2. Role of tolerogen conformation in induction of oral tolerance in experimental autoimmune myasthenia gravis.

    PubMed

    Im, S H; Barchan, D; Souroujon, M C; Fuchs, S

    2000-10-01

    We recently demonstrated that oral or nasal administration of recombinant fragments of the acetylcholine receptor (AChR) prevents the induction of experimental autoimmune myasthenia gravis (EAMG) and suppresses ongoing EAMG in rats. We have now studied the role of spatial conformation of these recombinant fragments in determining their tolerogenicity. Two fragments corresponding to the extracellular domain of the human AChR alpha-subunit and differing in conformation were tested: Halpha1-205 expressed with no fusion partner and Halpha1-210 fused to thioredoxin (Trx), and designated Trx-Halpha1-210. The conformational similarity of the fragments to intact AChR was assessed by their reactivity with alpha-bungarotoxin and with anti-AChR mAbs, specific for conformation-dependent epitopes. Oral administration of the more native fragment, Trx-Halpha1-210, at the acute phase of disease led to exacerbation of EAMG, accompanied by an elevation of AChR-specific humoral and cellular reactivity, increased levels of Th1-type cytokines (IL-2, IL-12), decreased levels of Th2 (IL-10)- or Th3 (TGF-beta)-type cytokines, and higher expression of costimulatory factors (CD28, CTLA4, B7-1, B7-2, CD40L, and CD40). On the other hand, oral administration of the less native fragments Halpha1-205 or denatured Trx-Halpha1-210 suppressed ongoing EAMG and led to opposite changes in the immunological parameters. It thus seems that native conformation of AChR-derived fragments renders them immunogenic and immunopathogenic and therefore not suitable for treatment of myasthenia gravis. Conformation of tolerogens should therefore be given careful attention when considering oral tolerance for treatment of autoimmune diseases. PMID:11034361

  3. Recombinant IgG2a Fc (M0451) Multimers Effectively Suppress Experimental Autoimmune Myasthenia Gravis

    PubMed Central

    Thiruppathi, Muthusamy; Sheng, Jian Rong; Li, Liangcheng; Prabhakar, Bellur S.; Meriggioli, Matthew N.

    2014-01-01

    Myasthenia gravis (MG) is an autoimmune disorder caused by target-specific pathogenic antibodies directed toward postsynaptic neuromuscular junction (NMJ) proteins, most commonly the skeletal muscle nicotinic acetylcholine receptor (AChR). In MG, high-affinity anti-AChR Abs binding to the NMJ lead to loss of functional AChRs, culminating in neuromuscular transmission failure and myasthenic symptoms. Intravenous immune globulin (IVIg) has broad therapeutic application in the treatment of a range of autoimmune diseases, including MG, although its mechanism of action is not clear. Recently, the anti-inflammatory and anti-autoimmune activities of IVIg have been attributed to the IgG Fc domains. Soluble immune aggregates bearing intact Fc fragments have been shown to be effective treatment for a number of autoimmune disorders in mice, and fully recombinant multimeric Fc molecules have been shown to be effective in treating collagen-induced arthritis, murine immune thrombocytopenic purpura, and experimental inflammatory neuritis. In this study, a murine model of MG (EAMG) was used to study the effectiveness of this novel recombinant polyvalent IgG2a Fc (M045) in treating established myasthenia, with a direct comparison to treatment with IVIg. M045 treatment had profound effects on the clinical course of EAMG, accompanied by down-modulation of pathogenic antibody responses. These effects were associated with reduced B cell activation and T cell proliferative responses to AChR, an expansion in the population of FoxP3+ regulatory T cells, and enhanced production of suppressive cytokines, such as IL-10. Treatment was at least as effective as IVIg in suppressing EAMG, even at doses 25–30 fold lower. Multimeric Fc molecules offer the advantages of being recombinant, homogenous, available in unlimited quantity, free of risk from infection and effective at significantly reduced protein loads, and may represent a viable therapeutic alternative to polyclonal IVIg. PMID:24388113

  4. Suppression of experimental autoimmune myasthenia gravis by autologous T regulatory cells.

    PubMed

    Aricha, Revital; Reuveni, Debby; Fuchs, Sara; Souroujon, Miriam C

    2016-02-01

    Adoptive transfer of regulatory T (Treg) cells have been employed effectively for suppression of several animal models for autoimmune diseases. In order to employ Treg cell therapy in patients, it is necessary to generate Treg cells from the patient's own cells (autologous) that would be able to suppress effectively the disease in vivo, upon their reintroduction to the patient. Towards this objective, we report in the present study on a protocol for a successful immune-regulation of experimental autoimmune myasthenia gravis (EAMG) by ex vivo--generated autologous Treg cells. For this protocol bone marrow (BM) cells, are first cultured in the presence of GM-CSF, giving rise to a population of CD11c(+)MHCII(+)CD45RA(+)CD8(-) DCs (BMDCs). Splenic CD4(+) T cells are then co-cultured with the differentiated BM cells and expand to 90% of Foxp3(+) Treg cells. In vitro assay exhibits a similar dose dependent manner in the suppression of T effector cells proliferation between Treg cells obtained from either healthy or sick donors. In addition, both Treg cells inhibit similarly the secretion of IFN-γ from activated splenocytes. Administration of 1 × 10(6) ex-vivo generated Treg cells, I.V, to EAMG rats, modulates the disease following a single treatment, given 3 days or 3 weeks after disease induction. Similar disease inhibition was achieved when CD4 cells were taken from either healthy or sick donors. The disease suppression was accompanied by reduced levels of total AChR specific antibodies in the serum. Moreover, due to the polyclonality of the described Treg cell, we have examined whether this treatment approach could be also employed for the treatment of other autoimmune diseases involving Treg cells. Indeed, we demonstrated that the ex-vivo generated autologous Treg cells suppress Adjuvant Arthritis (AA) in rats. This study opens the way for the application of induced autologous Treg cell therapy for myasthenia gravis, as well as for other human autoimmune diseases

  5. Assays for myasthenia gravis

    SciTech Connect

    Lindstrom, J.M.

    1988-12-06

    This patent describes an improvement in a process for diagnosing myasthenia gravis. The process comprises the steps of preparing a complex of acetycholine receptor protein, toxin and a radioactive isotope, incubating the complex with a serum sample from a patient so as to join antibodies engendered in connection with myasthenia gravis to the complex, precipitating the complex joined with antibody with anti-immunoglobulin and measuring radioactivity, from the radioactive isotope, of the precipitated complex. The improvement is that the acetylcholine receptor protein is derived from cells of the TE671 Line.

  6. Overview of myasthenia gravis.

    PubMed

    Arora, Yeeshu; Li, Yuebing

    2013-01-01

    Myasthenia gravis is an antibody-mediated disorder of neuromuscular transmission that is characterized by weakness and fatigue of voluntary muscles. Weakness may be ocular, bulbar, or generalized. Diagnostic evaluation of patients consists of bedside assessment, antibody testing, and electrophysiologic studies. Various therapeutic options are available, which consist of anticholinesterase inhibitors for symptomatic management, immunosuppressive agents as maintenance therapy, and thymectomy. Plasmapheresis and intravenous immunoglobulin are used in patients in crisis or those with rapidly worsening or refractory symptoms. In our article, we elaborate on key aspects of the epidemiology, pathogenesis, diagnostic evaluation, and therapeutic options for patients with myasthenia gravis. PMID:24145588

  7. [Umbilical cord mesenchymal stem cell transplantation for treatment of experimental autoimmune myasthenia gravis in rats].

    PubMed

    Yu, Jing-Xia; Chen, Fang; Sun, Jun; Wang, Ji-Ming; Zhao, Qin-Jun; Ren, Xin-Jun; Ma, Feng-Xia; Yang, Shao-Guang; Han, Zhi-Bo; Han, Zhong-Chao

    2011-06-01

    Umbilical cord mesenchymal stem cell (UCMSC) transplantation has been widely used in the treatment of a variety of diseases due to their advantages such as abundant resources, low immunogenicity and large ex vivo expansion capacity. This study was aimed to investigate the effects of UCMSC on experimental autoimmune myasthenia gravis (EAMG) rats. The distribution of human-derived cells was observed by immunofluorescence method, the effect of MSC on B-cell in situ-secreted antibodies was assayed by ELISPOT, the secreted IFN-γ level was detected by using Transwell test. The results showed that UCMSC were able to migrate to inflammation region and lymph nudes, moreover human-derived cells could be detected in medulla zone of lymph nudes. In vitro in situ detection of AchR specific antibody secretion revealed that the full contact of MSC with lymphnode-derived lymphocytes could effectively inhibit production of AchR antibody. Transwell test indicated that the direct contact of UCMSC with CD4 T cells could effectively decrease production of IFN-γ, which modulated the unbalance between Th1/Th2 to a certain extent. It is concluded that UCMSC can regulate the immune system by direct cell-cell contact or/and release of cytokines, which bring a new insight into knowledge about MSC-based therapy for EAMG. PMID:21729563

  8. Coexistent autoimmune autonomic ganglionopathy and myasthenia gravis associated with non-small-cell lung cancer.

    PubMed

    Peltier, Amanda C; Black, Bonnie K; Raj, Satish R; Donofrio, Peter; Robertson, David; Biaggioni, Italo

    2010-03-01

    We report the case of a 55-year-old man with non-small-cell lung cancer who underwent radiation, chemotherapy with carbotaxol and paclitaxel, and left upper lobe removal 2 years prior to evaluation. He was referred for disabling orthostatic hypotension (113/69 mm Hg supine and 66/47 mm Hg standing after 10 minutes) without a compensatory heart rate increase (57 to 59 beats per minute), fatigue, and constipation with episodes of ileus. Clinical examination showed mild ptosis bilaterally, fatiguable neck flexor weakness, and hip flexor weakness. Blood pressure response to Valsalva maneuver was abnormal with an absence of phase 4 overshoot and a Valsalva heart rate ratio of 1.04. Plasma norepinephrine level was low (79 pg/ml supine, 330 pg/ml standing). Single-fiber electromyography of the right extensor digitorum communis revealed normal mean consecutive difference (jitter) but several pairs exceeded a jitter of 100 mus. Antibodies against muscle acetylcholine receptor [(AChR) 0.66 nmol/L, normal <0.02 nmol/L] and ganglionic AChR (0.34 nmol/L, normal <0.02 nmol/L) were present. Treatment with plasma exchange normalized responses to standing posture (105/68 supine to 118/82 mm Hg standing, 66 to 79 beats per minute), to Valsalva (normal blood pressure overshoot, hazard ratio 1.47), norepinephrine (194 pg/ml supine, 763 pg/ml standing), and jitter measurements. We conclude that autoimmune autonomic ganglionopathy and myasthenia gravis can coexist and suggest that the latter should be excluded in patients with autoimmune autonomic ganglionopathy who complain of fatigue that shows improvement with non-supine rest. PMID:19882640

  9. Suppression of experimental myasthenia gravis, a B cell-mediated autoimmune disease, by blockade of IL-18.

    PubMed

    Im, S H; Barchan, D; Maiti, P K; Raveh, L; Souroujon, M C; Fuchs, S

    2001-10-01

    Interleukin-18 (IL-18) is a pleiotropic proinflammatory cytokine that plays an important role in interferon gamma (IFN-gamma) production and IL-12-driven Th1 phenotype polarization. Increased expression of IL-18 has been observed in several autoimmune diseases. In this study we have analyzed the role of IL-18 in an antibody-mediated autoimmune disease and elucidated the mechanisms involved in disease suppression mediated by blockade of IL-18, using experimental autoimmune myasthenia gravis (EAMG) as a model. EAMG is a T cell-regulated, antibody-mediated autoimmune disease in which the nicotinic acetylcholine receptor (AChR) is the major autoantigen. Th1- and Th2-type responses are both implicated in EAMG development. We show that treatment by anti-IL-18 during ongoing EAMG suppresses disease progression. The protective effect can be adoptively transferred to naive recipients and is mediated by increased levels of the immunosuppressive Th3-type cytokine TGF-beta and decreased AChR-specific Th1-type cellular responses. Suppression of EAMG is accompanied by down-regulation of the costimulatory factor CD40L and up-regulation of CTLA-4, a key negative immunomodulator. Our results suggest that IL-18 blockade may potentially be applied for immunointervention in myasthenia gravis. PMID:11641240

  10. Thymus irradiation for myasthenia gravis

    SciTech Connect

    Currier, R.D.; Routh, A.; Hickman, B.T.; Douglas, M.A.

    1983-01-01

    Twenty-eight patients with progressive myasthenia gravis without thymoma received treatment of 3000 rads (30 Gy) to the anterior mediastinum, and a followup was conducted for five to 18 years. Twenty-four patients had generalized myasthenia, and four had ocular myasthenia gravis. Twenty patients with generalized myasthenia survived the several month post-treatment period and improved, but four died during that period. The improvement lasted a median of 1.5 years, and older patients had longer remissions than younger patients. The four patients who had ocular myasthenia did not change after treatment. Mediastinal irradiation produces a temporary remission in generalized myasthenia.

  11. Thymomatous myasthenia gravis.

    PubMed

    Pandit, L; Rao, S N

    1995-08-01

    Ten cases of thymoma associated myasthenia were seen in the last 7 years. They constitute 17.2% of all cases of Myasthenia gravis seen during the same period. Five of these patients presented in the third decade, all of them presenting with acute generalised Myasthenia (Osserman stage-III). Two patients presented with tumour related symptoms of chest pain, cough and dyspnea both of them having large, invasive and partially resectable tumours. Five patients underwent complete thymectomy and 3 patients underwent partial resection of tumour. Two patients underwent radiotherapy subsequently. Histologically, mixed lymphoepithelial tumours were common (70%). Tumour recurrence was seen in one patient. Two patients died, one in the post operative period. The surviving 8 patients followed up over 1-8 years remained in partial remission, on maintenance dose of steroids. The special problems related to thymomatous MG and practical approach to management are highlighted. PMID:8772974

  12. Prevention of passively transferred experimental autoimmune myasthenia gravis by a phage library-derived cyclic peptide

    PubMed Central

    Venkatesh, Natarajan; Im, Sin-Heyog; Balass, Moshe; Fuchs, Sara; Katchalski-Katzir, Ephraim

    2000-01-01

    Many pathogenic antibodies in myasthenia gravis (MG) and its animal model, experimental autoimmune MG (EAMG), are directed against the main immunogenic region (MIR) of the acetylcholine receptor (AcChoR). These antibodies are highly conformation dependent; hence, linear peptides derived from native receptor sequences are poor candidates for their immunoneutralization. We employed a phage-epitope library to identify peptide-mimotopes capable of preventing the pathogenicity of the anti-MIR mAb 198. We identified a 15-mer peptide (PMTLPENYFSERPYH) that binds specifically to mAb 198 and inhibits its binding to AcChoR. A 10-fold increase in the affinity of this peptide was achieved by incorporating flanking amino acid residues from the coat protein as present in the original phage library. This extended peptide (AEPMTLPENYFSERPYHPPPP) was constrained by the addition of cysteine residues on both ends of the peptide, thus generating a cyclic peptide that inhibited the binding of mAb 198 to AcChoR with a potency that is three orders of magnitude higher when compared with the parent library peptide. This cyclic peptide inhibited the in vitro binding of mAb 198 to AcChoR and prevented the antigenic modulation of AcChoR caused by mAb 198 in human muscle cell cultures. The cyclic peptide also reacted with several other anti-MIR mAbs and the sera of EAMG rats. In addition, this peptide blocked the ability of mAb 198 to passively transfer EAMG in rats. Further derivatization of the cyclic peptide may aid in the design of suitable synthetic mimotopes for modulation of MG. PMID:10639153

  13. "Warming yang and invigorating qi" acupuncture alters acetylcholine receptor expression in the neuromuscular junction of rats with experimental autoimmune myasthenia gravis.

    PubMed

    Huang, Hai-Peng; Pan, Hong; Wang, Hong-Feng

    2016-03-01

    Myasthenia gravis is an autoimmune disorder in which antibodies have been shown to form against the nicotinic acetylcholine nicotinic postsynaptic receptors located at the neuromuscular junction. "Warming yang and invigorating qi" acupuncture treatment has been shown to reduce serum inflammatory cytokine expression and increase transforming growth factor beta expression in rats with experimental autoimmune myasthenia gravis. However, few studies have addressed the effects of this type of acupuncture on the acetylcholine receptors at the neuromuscular junction. Here, we used confocal laser scanning microscopy to examine the area and density of immunoreactivity for an antibody to the nicotinic acetylcholine receptor at the neuromuscular junction in the phrenic nerve of rats with experimental autoimmune myasthenia gravis following "warming yang and invigorating qi" acupuncture therapy. Needles were inserted at acupressure points Shousanli (LI10), Zusanli (ST36), Pishu (BL20), and Shenshu (BL23) once daily for 7 consecutive days. The treatment was repeated after 1 day of rest. We found that area and the integrated optical density of the immunoreactivity for the acetylcholine receptor at the neuromuscular junction of the phrenic nerve was significantly increased following acupuncture treatment. This outcome of the acupuncture therapy was similar to that of the cholinesterase inhibitor pyridostigmine bromide. These findings suggest that "warming yang and invigorating qi" acupuncture treatment increases acetylcholine receptor expression at the neuromuscular junction in a rat model of autoimmune myasthenia gravis. PMID:27127487

  14. “Warming yang and invigorating qi” acupuncture alters acetylcholine receptor expression in the neuromuscular junction of rats with experimental autoimmune myasthenia gravis

    PubMed Central

    Huang, Hai-peng; Pan, Hong; Wang, Hong-feng

    2016-01-01

    Myasthenia gravis is an autoimmune disorder in which antibodies have been shown to form against the nicotinic acetylcholine nicotinic postsynaptic receptors located at the neuromuscular junction. “Warming yang and invigorating qi” acupuncture treatment has been shown to reduce serum inflammatory cytokine expression and increase transforming growth factor beta expression in rats with experimental autoimmune myasthenia gravis. However, few studies have addressed the effects of this type of acupuncture on the acetylcholine receptors at the neuromuscular junction. Here, we used confocal laser scanning microscopy to examine the area and density of immunoreactivity for an antibody to the nicotinic acetylcholine receptor at the neuromuscular junction in the phrenic nerve of rats with experimental autoimmune myasthenia gravis following “warming yang and invigorating qi” acupuncture therapy. Needles were inserted at acupressure points Shousanli (LI10), Zusanli (ST36), Pishu (BL20), and Shenshu (BL23) once daily for 7 consecutive days. The treatment was repeated after 1 day of rest. We found that area and the integrated optical density of the immunoreactivity for the acetylcholine receptor at the neuromuscular junction of the phrenic nerve was significantly increased following acupuncture treatment. This outcome of the acupuncture therapy was similar to that of the cholinesterase inhibitor pyridostigmine bromide. These findings suggest that “warming yang and invigorating qi” acupuncture treatment increases acetylcholine receptor expression at the neuromuscular junction in a rat model of autoimmune myasthenia gravis. PMID:27127487

  15. Myasthenia Gravis: Medical Aspects

    PubMed Central

    Zeldowicz, Ludmila R.; Buckler, William St. John

    1965-01-01

    The diagnosis of myasthenia gravis is often difficult and calls for a broader use of pharmacological and electrodiagnostic tests. The decamethonium-edrophonium test, which has proved superior to other procedures for this purpose, is based on neurophysiological principles and depicts the behaviour of the neuromuscular junction. A state of resistance to depolarizing agents in the limited form of myasthenia and a state of a non-depolarizing (competitive) block in advanced cases has been shown. This test has demonstrated that the neuromuscular defect exists throughout the skeletal musculature, including muscles clinically unaffected. It produced no false-positive results either in normal or neurasthenic persons or in patients with neurological diseases with myasthenic symptoms. In a patient with botulism and in a patient with ocular palsies from brain-stem encephalitis the edrophonium test gave a false-positive result, while the decamethonium-edrophonium test was negative. Diagnosis, treatment and management of myasthenic emergencies are described. PMID:14323662

  16. Muscle autoantibodies in myasthenia gravis: beyond diagnosis?

    PubMed Central

    Meriggioli, Matthew N; Sanders, Donald B

    2012-01-01

    Myasthenia gravis is an autoimmune disorder of the neuromuscular junction. A number of molecules, including ion channels and other proteins at the neuromuscular junction, may be targeted by autoantibodies leading to abnormal neuromuscular transmission. In approximately 85% of patients, autoantibodies, directed against the postsynaptic nicotinic acetylcholine receptor can be detected in the serum and confirm the diagnosis, but in general, do not precisely predict the degree of weakness or response to therapy. Antibodies to the muscle-specific tyrosine kinase are detected in approximately 50% of generalized myasthenia gravis patients who are seronegative for anti-acetylcholine receptor antibodies, and levels of anti-muscle-specific tyrosine kinase antibodies do appear to correlate with disease severity and treatment response. Antibodies to other muscle antigens may be found in the subsets of myasthenia gravis patients, potentially providing clinically useful diagnostic information, but their utility as relevant biomarkers (measures of disease state or response to treatment) is currently unclear. PMID:22882218

  17. MuSK induced experimental autoimmune myasthenia gravis does not require IgG1 antibody to MuSK.

    PubMed

    Küçükerden, Melike; Huda, Ruksana; Tüzün, Erdem; Yılmaz, Abdullah; Skriapa, Lamprini; Trakas, Nikos; Strait, Richard T; Finkelman, Fred D; Kabadayı, Sevil; Zisimopoulou, Paraskevi; Tzartos, Socrates; Christadoss, Premkumar

    2016-06-15

    Sera of myasthenia gravis (MG) patients with muscle-specific receptor kinase-antibody (MuSK-Ab) predominantly display the non-complement fixing IgG4 isotype. Similarly, mouse IgG1, which is the analog of human IgG4, is the predominant isotype in mice with experimental autoimmune myasthenia gravis (EAMG) induced by MuSK immunization. The present study was performed to determine whether IgG1 anti-MuSK antibody is required for immunized mice to develop EAMG. Results demonstrated a significant correlation between clinical severity of EAMG and levels of MuSK-binding IgG1+, IgG2+ and IgG3+ peripheral blood B cells in MuSK-immunized wild-type (WT) mice. Moreover, MuSK-immunized IgG1 knockout (KO) and WT mice showed similar EAMG severity, serum MuSK-Ab levels, muscle acetylcholine receptor concentrations, neuromuscular junction immunoglobulin and complement deposit ratios. IgG1 and IgG3 were the predominant anti-MuSK isotypes in WT and IgG1 KO mice, respectively. These observations demonstrate that non-IgG1 isotypes can mediate MuSK-EAMG pathogenesis. PMID:27235354

  18. Evidence of enhanced recombinant interleukin-2 sensitivity in thymic lymphocytes from patients with myasthenia gravis: possible role in autoimmune pathogenesis.

    PubMed

    Cohen-Kaminsky, S; Levasseur, P; Binet, J P; Berrih-Aknin, S

    1989-09-01

    We evaluated the activation state of thymic lymphocytes in patients with myasthenia gravis (MG) by cytofluorographic analysis of CD25 expression and by testing their sensitivity to recombinant interleukin-2 (rIL-2) in the absence of any known previous stimulation. We detected no phenotypic signs of activation in fresh MG thymic lymphocyte suspensions, while functional signs of activation were reflected in a significantly higher sensitivity to rIL-2 in MG patients than in controls. The responses to rIL-2 were time- and dose-dependent, were inhibited by a blocking anti-IL-2 receptor antibody, and were associated with an increase in CD25+ T cells in both patients and controls. The T cells with functional signs of previous activation may represent autoreactive cells involved in the autoimmune process and confirm thymus gland hyperactivity in MG. These cells could result from primary autosensitization against the thymic acetylcholine receptor (AChR)-like molecule or from altered migration of peripheral activated cells into an abnormal thymic environment. Our results also provide a clue for understanding the effect of thymectomy in myasthenia gravis. PMID:2808688

  19. Modulation of the anti-acetylcholine receptor response and experimental autoimmune myasthenia gravis by recombinant fragments of the acetylcholine receptor.

    PubMed

    Barchan, D; Asher, O; Tzartos, S J; Fuchs, S; Souroujon, M C

    1998-02-01

    Myasthenia gravis (MG) is a neuromuscular disorder of man caused by a humoral response to the acetylcholine receptor (AChR). Most of the antibodies in MG and in experimental autoimmune myasthenia gravis (EAMG) are directed to the extracellular portion of the AChR alpha subunit, and within it, primarily to the main immunogenic region (MIR). We have cloned and expressed recombinant fragments, corresponding to the entire extracellular domain of the AChR alpha subunit (H alpha1-210), and to portions of it that encompass either the MIR (H alpha1-121) or the ligand binding site of AChR (H alpha122-210), and studied their ability to interfere with the immunopathological anti-AChR response in vitro and in vivo. All fragments were expressed as fusion proteins with glutathione S-transferase. Fragments H alpha1-121 and H alpha1-210 protected AChR in TE671 cells against accelerated degradation induced by the anti-MIR monoclonal antibody (mAb)198 in a dose-dependent manner. Moreover, these fragments had a similar effect on the antigenic modulation of AChR by other anti-MIR mAb and by polyclonal rat anti-AChR antibodies. Fragments H alpha1-121 and H alpha1-210 were also able to modulate in vivo muscle AChR loss and development of clinical symptoms of EAMG, passively transferred to rats by mAb 198. Fragment H alpha122-210 did not have such a protective activity. Our results suggest that the appropriate recombinant fragments of the human AChR may be employed in the future for antigen-specific therapy of myasthenia. PMID:9521072

  20. Lymphocyte function in myasthenia gravis.

    PubMed Central

    Kawanami, S; Kanaide, A; Itoyama, Y; Kuroiwa, Y

    1979-01-01

    Mitogen-induced blastoid transformation of peripheral blood lymphocytes from patients with myasthenia gravis was studied using a microplate culture technique and evaluated with 3H-thymidine incorporation. It was found that both phytohaemagglutinin and pokeweed mitogen responses decreased significantly in patients with myasthenia gravis. In myasthenic crisis, indices of stimulation by phytohaemagglutination became very low. The autologous plasma neither inhibited nor facilitated mitogenic responses of lymphocytes. The decreased mitogen responsiveness of lymphocytes suggests that part of the T lymphocyte function is subnormal in myasthenia. PMID:490180

  1. CD1dhiCD5+ B cells Expanded by GM-CSF in Vivo Suppress Experimental Autoimmune Myasthenia Gravis

    PubMed Central

    Sheng, Jian Rong; Quan, Songhua; Soliven, Betty

    2014-01-01

    IL-10-competent subset within CD1dhiCD5+ B cells, also known as B10 cells, has been shown to regulate autoimmune diseases. Whether B10 cells can prevent or suppress the development of experimental autoimmune myasthenia gravis (EAMG) has not been studied. In this study, we investigated whether low dose granulocyte macrophage-colony stimulating factor (GM-CSF), which suppresses EAMG, can expand B10 cells in vivo, and whether adoptive transfer of CD1dhiCD5+ B cells would prevent or suppress EAMG. We found that treatment of EAMG mice with low-dose GM-CSF increased the proportion of CD1dhiCD5+ B cells and B10 cells. In vitro co-culture studies revealed that CD1dhiCD5+ B cells altered T cell cytokine profile but did not directly inhibit T cell proliferation. On the other hand, CD1dhiCD5+ B cells inhibited B cell proliferation and its autoantibody production in an IL-10-dependent manner. Adoptive transfer of CD1dhiCD5+ B cells to mice could prevent disease as well as suppress EAMG after disease onset. This was associated with downregulation of mature dendritic cell markers and expansion of regulatory T cells resulting in the suppression of acetylcholine receptor (AChR)-specific T cell and B cell responses. Thus, our data have provided significant insights into the mechanisms underlying the tolerogenic effects of B10 cells in EAMG. These observations suggest that in vivo or in vitro expansion of CD1dhiCD5+ B cells or B10 cells may represent an effective strategy in the treatment of human myasthenia gravis. PMID:25135828

  2. Mouse models of myasthenia gravis.

    PubMed

    Ban, Joanne; Phillips, William D

    2015-01-01

    Myasthenia gravis is a muscle weakness disease characterized by autoantibodies that target components of the neuromuscular junction, impairing synaptic transmission. The most common form of myasthenia gravis involves antibodies that bind the nicotinic acetylcholine receptors in the postsynaptic membrane. Many of the remaining cases are due to antibodies against muscle specific tyrosine kinase (MuSK). Recently, autoantibodies against LRP4 (another component of the MuSK signaling complex in the postsynaptic membrane) were identified as the likely cause of myasthenia gravis in some patients. Fatiguing weakness is the common symptom in all forms of myasthenia gravis, but muscles of the body are differentially affected, for reasons that are not fully understood. Much of what we have learnt about the immunological and neurobiological aspects of the pathogenesis derives from mouse models. The most widely used mouse models involve either passive transfer of autoantibodies, or active immunization of the mouse with acetylcholine receptors or MuSK protein. These models can provide a robust replication of many of the features of the human disease. Depending upon the protocol, acute fatiguing weakness develops 2 - 14 days after the start of autoantibody injections (passive transfer) or might require repeated immunizations over several weeks (active models). Here we review mouse models of myasthenia gravis, including what they have contributed to current understanding of the pathogenic mechanisms and their current application to the testing of therapeutics. PMID:25777761

  3. Juvenile myasthenia gravis: a paediatric perspective.

    PubMed

    Finnis, Maria F; Jayawant, Sandeep

    2011-01-01

    Myasthenia gravis (MG) is an autoimmune disease in which antibodies are directed against the postsynaptic membrane of the neuromuscular junction, resulting in muscle weakness and fatigability. Juvenile myasthenia gravis (JMG) is a rare condition of childhood and has many clinical features that are distinct from adult MG. Prepubertal children in particular have a higher prevalence of isolated ocular symptoms, lower frequency of acetylcholine receptor antibodies, and a higher probability of achieving remission. Diagnosis in young children can be complicated by the need to differentiate from congenital myasthenic syndromes, which do not have an autoimmune basis. Treatment commonly includes anticholinesterases, corticosteroids with or without steroid-sparing agents, and newer immune modulating agents. Plasma exchange and intravenous immunoglobulin (IVIG) are effective in preparation for surgery and in treatment of myasthenic crisis. Thymectomy increases remission rates. Diagnosis and management of children with JMG should take account of their developmental needs, natural history of the condition, and side-effect profiles of treatment options. PMID:22110902

  4. [Myasthenia gravis and myasthenic syndromes].

    PubMed

    Marouf, W; Sieb, J P

    2009-08-01

    Neuromuscular transmission is compromised in a variety of disorders due to immunological, toxic or congenital mechanisms. Myasthenia gravis (MG) is the most frequent among these disorders. In about 15% of cases, MG is associated with a second autoimmune disorder mainly seen in rheumatologists. Some of the drugs used in rheumatology can exacerbate MG or even trigger immunologically the occurrence of MG. In most MG patients, antibodies to the acetylcholine receptor (AChR) are present, but around 10% have AChR antibodies that are only identified by novel methods, and up to 5% have muscle-specific kinase antibodies which define a different subgroup of myasthenia. Among those MG patients with anti-AChR antibodies, a number of clinical subtypes can be identified including early-onset MG (onset

  5. [Myasthenia gravis - optimal treatment and accurate diagnosis].

    PubMed

    Gilhus, Nils Erik; Kerty, Emilia; Løseth, Sissel; Mygland, Åse; Tallaksen, Chantal

    2016-07-01

    Around 700 people in Norway have myasthenia gravis, an autoimmune disease that affects neuromuscular transmission and results in fluctuating weakness in some muscles as its sole symptom. The diagnosis is based on typical symptoms and findings, detection of antibodies and neurophysiological examination. Symptomatic treatment with acetylcholinesterase inhibitors is generally effective, but most patients also require immunosuppressive drug treatment. Antigen-specific therapy is being tested in experimental disease models. PMID:27381787

  6. [Autoantibodies in myasthenia gravis].

    PubMed

    Motomura, Masakatsu; Narita Masuda, Tomoko

    2013-04-01

    Myasthenia gravis (MG) is caused by the failure of neuromuscular transmission mediated by pathogenic autoantibodies (Abs). Generally, patients with MG are divided into 3 groups: (1) nicotinic acetylcholine receptor antibody-positive MG (AChR-MG: 80%), (2) muscle-specific receptor tyrosine kinase antibody-positive MG (MuSK-MG: 5-10%), which are AChR-associated transmembrane post-synaptic proteins involved in AChR aggregation, and (3) double-seronegative MG. In 2011, autoantibodies against low-density lipoprotein receptor-related protein 4 (Lrp4) were identified in Japanese MG patients, and thereafter, have been reported in Germany and USA. We developed a simple technique termed Gaussia luciferase immunoprecipitation (GLIP) for detecting the antibodies to Lrp4. Our results showed that 9 generalized MG patients out of 300 without AChR Ab were positive for Lrp4 antibodies. These antibodies inhibit the binding of Lrp4 to its ligand and predominantly belong to the IgG1 subclass. In other studies, Lrp4 Ab-positive sera inhibited agrin-induced aggregation of AChRs in cultured myotubes, suggesting a pathogenic role in the dysfunction of the neuromuscular endplate. Further understanding of the structure and function of neuromuscular junction (NMJ) through newly discovered autoantibodies may provide specific clinical information and treatment for MG. PMID:23568991

  7. Treatment of myasthenia gravis: current practice and future directions.

    PubMed

    Ciafaloni, Emma; Sanders, Donald B

    2002-09-01

    Myasthenia gravis is the best understood of the autoimmune diseases and a number of treatments are currently used to produce clinical improvement. However, due to the scarcity of evidence-based and comparative data, there is still no consensus on many therapeutic issues. Even a widely accepted treatment like thymectomy has never been proven effective by a well-designed trial. These are just some of the unanswered questions: What is the best treatment algorithm and safest long-term management of myasthenia gravis? What patients are likely to benefit from thymectomy? How long should myasthenia gravis patients be treated? Is it possible to discontinue immunotherapy once remission has been achieved? What are the risks associated with long-term immunosuppression? In this article, we review current therapeutic strategies and these unresolved questions about myasthenia gravis treatment. PMID:19810991

  8. Myasthenia gravis: an update for the clinician.

    PubMed

    Sieb, J P

    2014-03-01

    This paper provides a thorough overview of the current advances in diagnosis and therapy of myasthenia gravis (MG). Nowadays the term 'myasthenia gravis' includes heterogeneous autoimmune diseases, with a postsynaptic defect of neuromuscular transmission as the common feature. Myasthenia gravis should be classified according to the antibody specificity [acetylcholine, muscle-specific receptor tyrosine kinase (MuSK), low-density lipoprotein receptor-related protein 4 (LRP4), seronegative], thymus histology (thymitis, thymoma, atrophy), age at onset (in children; aged less than or more than 50 years) and type of course (ocular or generalized). With optimal treatment, the prognosis is good in terms of daily functions, quality of life and survival. Symptomatic treatment with acetylcholine esterase inhibition is usually combined with immunosuppression. Azathioprine still remains the first choice for long-term immunosuppressive therapy. Alternative immunosuppressive options to azathioprine include cyclosporin, cyclophosphamide, methotrexate, mycophenolate mofetil and tacrolimus. Rituximab is a promising new drug for severe generalized MG. Emerging therapy options include belimumab, eculizumab and the granulocyte- macrophage colony-stimulating factor. One pilot study on etanercept has given disappointing results. For decades, thymectomy has been performed in younger adults to improve non-paraneoplastic MG. However, controlled prospective studies on the suspected benefit of this surgical procedure are still lacking. In acute exacerbations, including myasthenic crisis, intravenous immunoglobulin, plasmapheresis and immunoadsorption are similarly effective. PMID:24117026

  9. Clinical electrophysiology in myasthenia gravis.

    PubMed Central

    Stalberg, E

    1980-01-01

    Effective diagnostic methods are of great importance in order to recognise myasthenic patients among those with muscle fatigability. Intracellular recordings are useful for research work within the field and for detailed description of the motor end-plate's physiology in the individual case. The method is not used for the routine diagnosis of myasthenia gravis. The decrement of the electrical muscle response with nerve stimulation is the most commonly used method. The diagnostic yield is higher in proximal muscles, in warmed muscles, after exercise, and after ischaemia. A significant number of patients may be undiagnosed with this technique. The mechanical response with nerve stimulation shows the same type of decrement but also an abnormal response to long stimulation. The diagnostic value of this is under dispute. Single fibre ENG needs more patient cooperation than do these tests. The diagnostic yield is significantly higher. Some patients considered to have myasthenia gravis do not show any abnormalities with this technique, particularly those with the pure ocular form. Conventional EMG is not useful for the diagnosis of myasthenia, but may be indicated in these patients when concurrent nerve or muscle disease is in question. Tests for eye movement fatique have not proved useful. Stapedius reflex fatigability is demonstrated in about the same proportion of patients as have positive SFEMG findings. The technique is not uncomfortable for the patient and requires minimal cooperation. The general usefulness must be assessed by further routine use. Even with the advent of immunological tests, neurophysiological investigations are indispensable in helping establish the diagnosis of myasthenia gravis. Discrepancies between the results comparing electrophysiological and immunological tests may indicate that myasthenia gravis is a heterogenous entity within which subgroups may be identified. PMID:6249895

  10. Ocular myasthenia gravis: A review

    PubMed Central

    Nair, Akshay Gopinathan; Patil-Chhablani, Preeti; Venkatramani, Devendra V; Gandhi, Rashmin Anilkumar

    2014-01-01

    Myasthenia gravis (MG) is a disease that affects the neuro-muscular junction resulting in classical symptoms of variable muscle weakness and fatigability. It is called the great masquerader owing to its varied clinical presentations. Very often, a patient of MG may present to the ophthalmologist given that a large proportion of patients with systemic myasthenia have ocular involvement either at presentation or during the later course of the disease. The treatment of ocular MG involves both the neurologist and ophthalmologist. Thus, the aim of this review was to highlight the current diagnosis, investigations, and treatment of ocular MG. PMID:25449931

  11. Pemphigus foliaceus exacerbated by radiation, in association with myasthenia gravis.

    PubMed

    Liebman, Tracey N; Lieberman, Miriam R; Burris, Katy

    2016-01-01

    Pemphigus foliaceus (PF) is a sporadic autoimmune blistering disease of unknown etiology. The production of immunoglobulin G4 antibodies against desmoglein-1 is responsible for the clinical manifestation of PF. We present a case of a woman with a recent diagnosis of myasthenia gravis (MG), who was also recently treated with radiation therapy for breast cancer. The clinical exam, supported by biopsy and direct immunofluorescence, were consistent with PF. We present this case to increase the awareness of the potential exacerbation or induction of PF with radiation, and of the association of PF and myasthenia gravis. Only five prior cases of radiation-exacerbated or radiation-induced PF have been reported in the literature to date. Furthermore, the co-existence of the autoimmune entities of myasthenia gravis and PF has been reported in the literature in only 9 cases and was also noted in this patient. PMID:27136623

  12. Seronegative Maternal Ocular Myasthenia Gravis and Delayed Transient Neonatal Myasthenia Gravis

    PubMed Central

    Townsel, Courtney; Keller, Rebecca; Johnson, Kendall; Hussain, Naveed; Campbell, Winston A.

    2016-01-01

    Background Myasthenia gravis (MG) is an autoimmune disorder with fluctuating muscle weakness, divided into generalized and localized (ocular) forms. Maternal antibodies to acetylcholine receptors cross the placenta and may cause transient neonatal myasthenia gravis (TNMG). We present a case of seronegative maternal ocular MG and delayed TNMG. Case A 29-year-old G3P1011 underwent cesarean birth of a male infant who developed oxygen desaturation requiring supplemental oxygen on day of life (DOL) 3. Based on the clinical course and after exclusion of other diagnoses, the infant was diagnosed with TNMG. Infant's condition improved spontaneously and he was weaned off supplemental oxygen and discharged home on DOL 12. Conclusion Infants born to mothers with seronegative localized (ocular) MG are also susceptible to TNMG which may be late in onset. PMID:26989568

  13. The CD45 77C/G allele is not associated with myasthenia gravis - a reassessment of the potential role of CD45 in autoimmunity

    PubMed Central

    2010-01-01

    Background The G allele of the CD45 77C/G SNP (rs17612648), which has previously been suggested to be associated with autoimmune disorders, was genotyped in 446 Swedish myasthenia gravis (MG) patients and 2303 matched controls. Results There was no association between the polymorphism and patient group as a whole (p = 0.199), nor with clinical subgroups. Our results add to a growing number of studies unable to find association between the 77C/G polymorphism and autoimmune disorders. One control sample, from an adult blood donor, was homozygous for the G allele, yet negative for a panel of auto-antibodies, representing the first homozygous individual studied in this respect. Conclusions The 77C/G mutation does not predispose to MG, and its role in autoimmunity may have to be re-evaluated. PMID:21067564

  14. Myasthenia Gravis Medication Information Card (Drugs to be Avoided or Used with Caution in Myasthenia Gravis)

    MedlinePlus

    ... possibility whenever a new medication is prescribed. For questions regarding medications, contact ... “Medications and Myasthenia Gravis (A Reference for Health Care Professionals.” www.myasthenia. ...

  15. Profound Olfactory Dysfunction in Myasthenia Gravis

    PubMed Central

    Leon-Sarmiento, Fidias E.; Bayona, Edgardo A.; Bayona-Prieto, Jaime; Osman, Allen; Doty, Richard L.

    2012-01-01

    In this study we demonstrate that myasthenia gravis, an autoimmune disease strongly identified with deficient acetylcholine receptor transmission at the post-synaptic neuromuscular junction, is accompanied by a profound loss of olfactory function. Twenty-seven MG patients, 27 matched healthy controls, and 11 patients with polymiositis, a disease with peripheral neuromuscular symptoms analogous to myasthenia gravis with no known central nervous system involvement, were tested. All were administered the University of Pennsylvania Smell Identification Test (UPSIT) and the Picture Identification Test (PIT), a test analogous in content and form to the UPSIT designed to control for non-olfactory cognitive confounds. The UPSIT scores of the myasthenia gravis patients were markedly lower than those of the age- and sex-matched normal controls [respective means (SDs) = 20.15 (6.40) & 35.67 (4.95); p<0.0001], as well as those of the polymiositis patients who scored slightly below the normal range [33.30 (1.42); p<0.0001]. The latter finding, along with direct monitoring of the inhalation of the patients during testing, implies that the MG-related olfactory deficit is unlikely due to difficulties sniffing, per se. All PIT scores were within or near the normal range, although subtle deficits were apparent in both the MG and PM patients, conceivably reflecting influences of mild cognitive impairment. No relationships between performance on the UPSIT and thymectomy, time since diagnosis, type of treatment regimen, or the presence or absence of serum anti-nicotinic or muscarinic antibodies were apparent. Our findings suggest that MG influences olfactory function to the same degree as observed in a number of neurodegenerative diseases in which central nervous system cholinergic dysfunction has been documented. PMID:23082113

  16. Double seronegative myasthenia gravis with antiphospholipid syndrome: a case report

    PubMed Central

    2014-01-01

    Introduction Myasthenia gravis is an autoimmune disease characterized by fluctuating muscle weakness. It is often associated with other autoimmune disorders, such as thyroid disease, rheumatoid arthritis, systemic lupus erythematosus, and antiphospholipid syndrome. Many aspects of autoimmune diseases are not completely understood, particularly when they occur in association, which suggests a common pathogenetic mechanism. Case presentation We report a case of a 42-year-old Caucasian woman with antiphospholipid syndrome, in whom myasthenia gravis developed years later. She tested negative for both antibodies against the acetylcholine receptor and against muscle-specific receptor tyrosine-kinase, but had typical decremental responses at the repetitive nerve stimulation testing, so that a generalized myasthenia gravis was diagnosed. Her thromboplastin time and activated partial thromboplastin time were high, anticardiolipin and anti-β2 glycoprotein-I antibodies were slightly elevated, as a manifestation of the antiphospholipid syndrome. She had a good clinical response when treated with a combination of pyridostigmine, prednisone and azathioprine. Conclusions Many patients with myasthenia gravis test positive for a large variety of auto-antibodies, testifying of an immune dysregulation, and some display mild T-cell lymphopenia associated with hypergammaglobulinemia and B-cell hyper-reactivity. Both of these mechanisms could explain the occurrence of another autoimmune condition, such as antiphospholipid syndrome, but further studies are necessary to shed light on this matter. Clinicians should be aware that patients with an autoimmune diagnosis such as antiphospholipid syndrome who develop signs and neurological symptoms suggestive of myasthenia gravis are at risk and should prompt an emergent evaluation by a specialist. PMID:24380508

  17. Innate immunity in myasthenia gravis thymus: pathogenic effects of Toll-like receptor 4 signaling on autoimmunity.

    PubMed

    Cordiglieri, Chiara; Marolda, Roberta; Franzi, Sara; Cappelletti, Cristina; Giardina, Carmelo; Motta, Teresio; Baggi, Fulvio; Bernasconi, Pia; Mantegazza, Renato; Cavalcante, Paola

    2014-08-01

    The thymus is the main site of immune sensitization to AChR in myasthenia gravis (MG). In our previous studies we demonstrated that Toll-like receptor (TLR) 4 is over-expressed in MG thymuses, suggesting its involvement in altering the thymic microenvironment and favoring autosensitization and autoimmunity maintenance processes, via an effect on local chemokine/cytokine network. Here, we investigated whether TLR4 signaling may favor abnormal cell recruitment in MG thymus via CCL17 and CCL22, two chemokines known to dictate immune cell trafficking in inflamed organs by binding CCR4. We also investigated whether TLR4 activation may contribute to immunodysregulation, via the production of Th17-related cytokines, known to alter effector T cell (Teff)/regulatory T cell (Treg) balance. We found that CCL17, CCL22 and CCR4 were expressed at higher levels in MG compared to normal thymuses. The two chemokines were mainly detected around medullary Hassall's corpuscles (HCs), co-localizing with TLR4(+) thymic epithelial cells (TECs) and CCR4(+) dendritic cells (DCs), that were present in higher number in MG thymuses compared to controls. TLR4 stimulation in MG TECs increased CCL17 and CCL22 expression and induced the production of Th17-related cytokines. Then, to study the effect of TLR4-stimulated TECs on immune cell interactions and Teff activation, we generated an in-vitro imaging model by co-culturing CD4(+) Th1/Th17 AChR-specific T cells, naïve CD4(+)CD25(+) Tregs, DCs and TECs from Lewis rats. We observed that TLR4 stimulation led to a more pronounced Teff activatory status, suggesting that TLR4 signaling in MG thymic milieu may affect cell-to-cell interactions, favoring autoreactive T-cell activation. Altogether our findings suggest a role for TLR4 signaling in driving DC recruitment in MG thymus via CCL17 and CCL22, and in generating an inflammatory response that might compromise Treg function, favoring autoreactive T-cell pathogenic responses. PMID:24397961

  18. Standardization of the experimental autoimmune myasthenia gravis (EAMG) model by immunization of rats with Torpedo californica acetylcholine receptors — Recommendations for methods and experimental designs

    PubMed Central

    Losen, Mario; Martinez-Martinez, Pilar; Molenaar, Peter C.; Lazaridis, Konstantinos; Tzartos, Socrates; Brenner, Talma; Duan, Rui-Sheng; Luo, Jie; Lindstrom, Jon; Kusner, Linda

    2015-01-01

    Myasthenia gravis (MG) with antibodies against the acetylcholine receptor (AChR) is characterized by a chronic, fatigable weakness of voluntary muscles. The production of autoantibodies involves the dysregulation of T cells which provide the environment for the development of autoreactive B cells. The symptoms are caused by destruction of the postsynaptic membrane and degradation of the AChR by IgG autoantibodies, predominantly of the G1 and G3 subclasses. Active immunization of animals with AChR from mammalian muscles, AChR from Torpedo or Electrophorus electric organs, and recombinant or synthetic AChR fragments generates a chronic model of MG, termed experimental autoimmune myasthenia gravis (EAMG). This model covers cellular mechanisms involved in the immune response against the AChR, e.g. antigen presentation, T cell-help and regulation, B cell selection and differentiation into plasma cells. Our aim is to define standard operation procedures and recommendations for the rat EAMG model using purified AChR from the Torpedo californica electric organ, in order to facilitate more rapid translation of preclinical proof of concept or efficacy studies into clinical trials and, ultimately, clinical practice. PMID:25796590

  19. [Therapeutic strategies against myasthenia gravis].

    PubMed

    Utsugisawa, Kimiaki; Nagane, Yuriko

    2013-05-01

    Many patients with myasthenia gravis (MG) still find it difficult to maintain daily activities due to chronic residual fatigability and long-term side effects of oral corticosteroids, since full remission is not common. Our analysis demonstrated that disease severity, oral corticosteroids, and depressive state are the major factors negatively associated with QOL, and that QOL of MM status patients taking < or = 5 mg prednisolne/day is identically good as that seen in CSR and is a target of treatment. In order to achieve early MM or better status with prednisolne < or = 5 mg/day, we advocate the early aggressive treatment strategy that can achieve early improvement by performing an aggressive therapy using combined treatment with plasmapheresis and high-dose intravenous methylprednisolone and then maintain an improved status using low-dose oral corticosteroids and calcineurin inhibitors. PMID:23777099

  20. Protective molecular mimicry in experimental myasthenia gravis.

    PubMed

    Im, Sin Hyeog; Barchan, Dora; Feferman, Tali; Raveh, Lily; Souroujon, Miriam C; Fuchs, Sara

    2002-05-01

    Protein databases were searched for microbial sequences that bear amino acid similarities with identified T- or B-cell epitopes within the human alpha-subunit of acetylcholine receptor (AChR). One peptide, derived from Haemophilus influenzae, exhibits 50% homology to an identified T-cell epitope of AChR alpha-subunit. This peptide was shown to have a protective effect in experimental autoimmune myasthenia gravis (EAMG). Pretreatment of rats with the mimicry peptide attenuated the induction and progression of EAMG. These effects were accompanied by a reduced T-cell response to AChR, diminished IL-2, IL-12, IFN-gamma and IL-4 levels, as well as decreased humoral response to self-AChR. PMID:12020961

  1. Impaired regulatory B cells in myasthenia gravis.

    PubMed

    Sheng, Jian Rong; Rezania, Kourosh; Soliven, Betty

    2016-08-15

    Regulatory B cells (Bregs) attenuate the severity of experimental autoimmune myasthenia gravis (EAMG) in an interleukin-10 (IL-10)-dependent manner. The goal of this study was to investigate the role of human Bregs in MG focusing on CD19(+)CD1d(hi) CD5(+) and CD19(+)CD24(hi)CD38(hi) subsets. We found that MG patients exhibited a decrease in the frequency of both Breg subsets and IL-10 producing B cells within each subset, which correlated with disease severity. In addition, there was impaired suppression of Th1 polarization in MG. These findings, taken together with EAMG data, indicate that Bregs play an important role in regulating the severity of MG. PMID:27397074

  2. Myasthenia gravis: past, present, and future

    PubMed Central

    Conti-Fine, Bianca M.; Milani, Monica; Kaminski, Henry J.

    2006-01-01

    Myasthenia gravis (MG) is an autoimmune syndrome caused by the failure of neuromuscular transmission, which results from the binding of autoantibodies to proteins involved in signaling at the neuromuscular junction (NMJ). These proteins include the nicotinic AChR or, less frequently, a muscle-specific tyrosine kinase (MuSK) involved in AChR clustering. Much is known about the mechanisms that maintain self tolerance and modulate anti-AChR Ab synthesis, AChR clustering, and AChR function as well as those that cause neuromuscular transmission failure upon Ab binding. This insight has led to the development of improved diagnostic methods and to the design of specific immunosuppressive or immunomodulatory treatments. PMID:17080188

  3. Congenital myasthenic syndromes and transient myasthenia gravis.

    PubMed

    Gajda, Anna; Szabó, Hajnalka; Gergev, Gyurgyinka; Karcagi, Veronika; Szabó, Nóra; Endreffy, Emoke; Túri, Sándor; Sztriha, László

    2013-05-30

    Hypotonia in the neonatal period and early infancy is a common clinical finding. It can be caused by various heterogeneous disorders of different origin which might lead to diagnostic difficulties. Disorders of the neuromuscular junction, such as congenital myasthenic syndromes and neonatal transient myasthenia gravis are among the aetiologies. We report on a case of congenital myasthenia caused by mutation in the long cytoplasmic loop of the epsilon subunit of the acetylcholine receptor and a neonate of a myasthenic mother diagnosed with transient myasthenia gravis. PMID:23909021

  4. Sensory aspects in myasthenia gravis: A translational approach.

    PubMed

    Leon-Sarmiento, Fidias E; Leon-Ariza, Juan S; Prada, Diddier; Leon-Ariza, Daniel S; Rizzo-Sierra, Carlos V

    2016-09-15

    Myasthenia gravis is a paradigmatic muscle disorder characterized by abnormal fatigue and muscle weakness that worsens with activities and improves with rest. Clinical and research studies done on nicotinic acetylcholine receptors have advanced our knowledge of the muscle involvement in myasthenia. Current views still state that sensory deficits are not "features of myasthenia gravis". This article discusses the gap that exists on sensory neural transmission in myasthenia that has remained after >300years of research in this neurological disorder. We outline the neurobiological characteristics of sensory and motor synapses, reinterpret the nanocholinergic commonalities that exist in both sensory and motor pathways, discuss the clinical findings on altered sensory pathways in myasthenia, and propose a novel way to score anomalies resulting from multineuronal inability associated sensory troubles due to eugenic nanocholinergic instability and autoimmunity. This medicine-based evidence could serve as a template to further identify novel targets for studying new medications that may offer a better therapeutic benefit in both sensory and motor dysfunction for patients. Importantly, this review may help to re-orient current practices in myasthenia. PMID:27538668

  5. Specific Immunotherapy of Experimental Myasthenia Gravis by A Novel Mechanism

    PubMed Central

    Luo, Jie; Kuryatov, Alexander; Lindstrom, Jon

    2009-01-01

    Objective Myasthenia gravis (MG) and its animal model, experimental autoimmune myasthenia gravis (EAMG), are antibody-mediated autoimmune diseases, in which autoantibodies bind to and cause loss of muscle nicotinic acetylcholine receptors (AChRs) at the neuromuscular junction. To develop a specific immunotherapy of MG, we treated rats with ongoing EAMG by intraperitoneal injection of bacterially-expressed human muscle AChR constructs. Methods Rats with ongoing EAMG received intraperitoneal treatment with the constructs weekly for 5 weeks beginning after the acute phase. Autoantibody concentration, subclassification, and specificity were analyzed to address underlying therapeutic mechanism. Results EAMG was specifically suppressed by diverting autoantibody production away from pathologically relevant specificities directed at epitopes on the extracellular surface of muscle AChRs toward pathologically irrelevant epitopes on the cytoplasmic domain. A mixture of subunit cytoplasmic domains was more effective than a mixture containing both extracellular and cytoplasmic domains or than only the extracellular domain of α1 subunits. Interpretation Therapy using only cytoplasmic domains, which lack pathologically relevant epitopes, avoids the potential liability of boosting the pathological response. Use of a mixture of bacterially-expressed human muscle AChR cytoplasmic domains for antigen-specific immunosuppression of myasthenia gravis has the potential to be specific, robust, and safe. PMID:20437579

  6. Association of myasthenia gravis and Behçet's disease: A case report.

    PubMed

    Kisabay, Aysin; Sari, Ummu Serpil; Boyaci, Recep; Batum, Melike; Yilmaz, Hikmet; Selcuki, Deniz

    2016-01-01

    Myasthenia gravis is a disease of neuromuscular junction due to auto-immune destruction of the acetylcholine receptors. Behçet's disease, on the other hand, is a multisystemic vascular-inflammatory disease. Both conditions are not common in the general population although their association has not been reported in the literature. We wanted to present our patient who developed clinical course of myasthenia gravis following discontinuation of medications due to complications of corticosteroid for Behçet's disease. It was observed that clinical findings of myasthenia gravis recovered following restarting steroid treatment and he did not experience attacks of both conditions. Although Myasthenia gravis and Behçet's disease are distinct entities clinically as well as in terms of pathogenesis, they share common physiopathological features and their treatment is based on their common features. PMID:27375145

  7. The potential role of cell surface complement regulators and circulating CD4+ CD25+ T-cells in the development of autoimmune myasthenia gravis

    PubMed Central

    Hamdoon, Mohamed Nasreldin Thabit; Fattouh, Mona; El-din, Asmaa Nasr; Elnady, Hassan M.

    2016-01-01

    Introduction CD4+CD25+ regulatory T-lymphocytes (T-regs) and regulators of complement activity (RCA) involving CD55 and CD59 play an important role in the prevention of autoimmune diseases. However, their role in the pathogenesis of human autoimmune myasthenia gravis (MG) remains unclear. This study aimed to determine the frequency of peripheral blood T-regs and CD4+ T-helper (T-helper) cells and the red blood cells (RBCs) level of expression of CD55 and CD59 in MG patients. Methods Fourteen patients with MG in neurology outpatient clinics of Sohag University Hospital and Sohag General Hospital from March 2014 to December 2014, and 10 age-matched healthy controls participated in this case-control study. We did flowcytometric assessments of the percentage of peripheral T-regs and T-helper cells and the level of expression of CD55 and CD59 on RBCs in the peripheral blood of patients and controls. Results There was a statistically significant decrease in the percentage of peripheral blood T-regs and T-regs/T-helper cell ratio in the MG patients group. Moreover, the level of expression of CD55, CD59, and dual expression of CD55/CD59 on RBCs were statistically significantly lower in MG patients than those of healthy controls. However, regression analysis indicated that there was no significant correlation between all the measured parameters and disease duration or staging. Conclusion Functional defects in the T-regs and RCA may play a role in the pathogenesis of autoimmune MG and their functional modulation may represent an alternative therapeutic strategy for MG treatment. PMID:26955441

  8. Deficits in Endogenous Adenosine Formation by Ecto-5′-Nucleotidase/CD73 Impair Neuromuscular Transmission and Immune Competence in Experimental Autoimmune Myasthenia Gravis

    PubMed Central

    Cristina Costa, Ana; Guerra-Gomes, Sónia; Ferreirinha, Fátima; Magalhães-Cardoso, Maria Teresa; Correia-de-Sá, Paulo

    2015-01-01

    AMP dephosphorylation via ecto-5′-nucleotidase/CD73 is the rate limiting step to generate extracellular adenosine (ADO) from released adenine nucleotides. ADO, via A2A receptors (A2ARs), is a potent modulator of neuromuscular and immunological responses. The pivotal role of ecto-5′-nucleotidase/CD73, in controlling extracellular ADO formation, prompted us to investigate its role in a rat model of experimental autoimmune myasthenia gravis (EAMG). Results show that CD4+CD25+FoxP3+ regulatory T cells express lower amounts of ecto-5′-nucleotidase/CD73 as compared to controls. Reduction of endogenous ADO formation might explain why proliferation of CD4+ T cells failed upon blocking A2A receptors activation with ZM241385 or adenosine deaminase in EAMG animals. Deficits in ADO also contribute to neuromuscular transmission failure in EAMG rats. Rehabilitation of A2AR-mediated immune suppression and facilitation of transmitter release were observed by incubating the cells with the nucleoside precursor, AMP. These findings, together with the characteristic increase in serum adenosine deaminase activity of MG patients, strengthen our hypothesis that the adenosinergic pathway may be dysfunctional in EAMG. Given that endogenous ADO formation is balanced by ecto-5′-nucleotidase/CD73 activity and that A2ARs exert a dual role to restore use-dependent neurocompetence and immune suppression in myasthenics, we hypothesize that stimulation of the two mechanisms may have therapeutic potential in MG. PMID:25691808

  9. Reversible man-in-the-barrel syndrome in myasthenia gravis

    PubMed Central

    Shah, Poornima A; Wadia, Pettarusp Murzban

    2016-01-01

    Man-in-the-barrel syndrome (MBS) is an uncommon presentation due to bilateral, predominantly proximal muscle weakness that has not been described to be associated with myasthenia gravis. We describe a case of myasthenia gravis presenting as MBS. Additionally, he had significant wasting of the deltoids bilaterally with fibrillations on electromyography (EMG) at rest and brief duration (3-6 ms) bi/triphasic motor unit potentials (MUPs) on submaximal effort apart from a decremental response on repetitive nerve stimulation (RNS) at 2 Hz. While electrophysiology is an important tool in the diagnosis of myasthenia gravis, pathological EMG patterns do not exclude the diagnosis of myasthenia gravis. PMID:27011638

  10. Unusual association of amyotrophic lateral sclerosis and myasthenia gravis: A dysregulation of the adaptive immune system?

    PubMed

    Del Mar Amador, Maria; Vandenberghe, Nadia; Berhoune, Nawel; Camdessanché, Jean-Philippe; Gronier, Sophie; Delmont, Emilien; Desnuelle, Claude; Cintas, Pascal; Pittion, Sophie; Louis, Sarah; Demeret, Sophie; Lenglet, Timothée; Meininger, Vincent; Salachas, François; Pradat, Pierre-François; Bruneteau, Gaëlle

    2016-06-01

    Myasthenia gravis is an autoimmune disorder affecting neuromuscular junctions that has been associated with a small increased risk of amyotrophic lateral sclerosis (ALS). Here, we describe a retrospective series of seven cases with a concomitant diagnosis of ALS and myasthenia gravis, collected among the 18 French reference centers for ALS in a twelve year period. After careful review, only six patients strictly met the diagnostic criteria for both ALS and myasthenia gravis. In these patients, limb onset of ALS was reported in five (83%) cases. Localization of myasthenia gravis initial symptoms was ocular in three (50%) cases, generalized in two (33%) and bulbar in one (17%). Median delay between onset of the two conditions was 19 months (6-319 months). Anti-acetylcholine receptor antibodies testing was positive in all cases. All patients were treated with riluzole and one had an associated immune-mediated disease. In the one last ALS case, the final diagnosis was false-positivity for anti-acetylcholine receptor antibodies. The co-occurrence of ALS and myasthenia gravis is rare and requires strict diagnostic criteria. Its demonstration needs thoughtful interpretation of electrophysiological results and exclusion of false positivity for myasthenia gravis antibody testing in some ALS cases. This association may be triggered by a dysfunction of adaptive immunity. PMID:27102004

  11. IL-17-producing CD4(+) T cells contribute to the loss of B-cell tolerance in experimental autoimmune myasthenia gravis.

    PubMed

    Schaffert, Hanne; Pelz, Andreas; Saxena, Abhishek; Losen, Mario; Meisel, Andreas; Thiel, Andreas; Kohler, Siegfried

    2015-05-01

    The role of Th17 cells in the pathogenesis of autoantibody-mediated diseases is unclear. Here, we assessed the contribution of Th17 cells to the pathogenesis of experimental autoimmune myasthenia gravis (EAMG), which is induced by repetitive immunizations with Torpedo californica acetylcholine receptor (tAChR). We show that a significant fraction of tAChR-specific CD4(+) T cells is producing IL-17. IL-17(ko) mice developed fewer or no EAMG symptoms, although the frequencies of tAChR-specific CD4(+) T cells secreting IL-2, IFN-γ, or IL-21, and the percentage of FoxP3(+) Treg cells were similar to WT mice. Even though the total anti-tAChR antibody levels were equal, the complement fixating IgG2b subtype was reduced in IL-17(ko) as compared to WT mice. Most importantly, pathogenic anti-murine AChR antibodies were significantly lower in IL-17(ko) mice. Furthermore, we confirmed the role of Th17 cells in EAMG pathogenesis by the reconstitution of TCR β/δ(ko) mice with WT or IL-17(ko) CD4(+) T cells. In conclusion, we show that the level of IgG2b and the loss of B-cell tolerance, which results in pathogenic anti-murine AChR-specific antibodies, are dependent on IL-17 production by CD4(+) T cells. Thus, we describe here for the first time how Th17 cells are involved in the induction of classical antibody-mediated autoimmunity. PMID:25676041

  12. A study of the utility of azathioprine metabolite testing in myasthenia gravis.

    PubMed

    Rae, William; Burke, Georgina; Pinto, Ashwin

    2016-04-15

    Myasthenia gravis (MG) is an autoimmune neuromuscular disorder characterised by fatigable voluntary skeletal muscle weakness. The underlying pathogenesis is complex involving adaptive autoimmune responses. Azathioprine remains a first line broad acting immunosuppressant for MG. Due to varied clinical responses to azathioprine we aimed to investigate the relationship between azathioprine metabolites and symptom control. Mild correlations between Quantitative Myasthenia Gravis Score (QMG) vs. 6-thioguanine nucleotides (R=-0.317 p=0.186) and QMG vs. lymphocyte count (R=0.402 p=0.08) were found. Azathioprine metabolite measurement should be considered in MG patients with; pancytopenia, deranged liver function or recurrent infections. PMID:27049566

  13. Prediction of aspiration in myasthenia gravis.

    PubMed

    Koopman, Wilma J; Wiebe, Samuel; Colton-Hudson, Angela; Moosa, Tas; Smith, Dean; Bach, David; Nicolle, Michael W

    2004-02-01

    Prediction of the risk of dysphagia and aspiration is important in the management of myasthenia gravis (MG). We assessed the ability of four bedside clinical tools to predict aspiration in 20 MG patients. Patients completed a self-directed questionnaire, underwent clinical neurological assessment and a bedside speech pathology assessment, and were assessed with the quantitative myasthenia gravis (QMG) score. The ability of these tools to predict aspiration was compared with the results of a modified barium swallow. Seven patients aspirated, 4 silently. The total self-directed questionnaire score, two specific questions on the self-directed questionnaire, the prediction based on clinical neurological assessment, and the QMG bulbar subset score all correlated with aspiration. The speech pathology prediction was highly sensitive but less specific. This pilot study shows that simple clinical tools can predict which MG patients are at risk of aspiration. PMID:14755491

  14. Myasthenia gravis treated with purified antithymocyte antiserum.

    PubMed

    Pirofsky, B; Reid, R H; Bardana, E J; Baker, R L

    1979-01-01

    The therapeutic effect of goat anti-human thymocyte antiserum globulin (ATG) was assessed in 10 patients with myasthenia gravis. All subjects had far-advanced, debilitating disease poorly responsive to anticholinesterase therapy. Prolonged, low-dose ATG therapy was used, with 1.0 to 2.6 gm ATG protein administered intramuscularly over a 28- to 73-day period. Therapeutic responses of varying degrees were noted in 8 of 10 patients. Completion of a course of ATG treatment and discontinuation of the drug did not lead to acute relapse. Follow-up examinations for over 5 years have been maintained. A mean remission period of approximately 2 years was observed. This therapy deserves further evaluation; subjects with progressive myasthenia gravis despite prior thymectomy may represent ideal candidates. PMID:311448

  15. Emergency Management of Myasthenia Gravis

    MedlinePlus

    ... head and shoulders. • Keep a calm and peaceful atmosphere. • Support respirations if needed. SEVERE SWALLOWING DIFFICULTY Subjective ... secretions as needed. • Keep a calm and peaceful atmosphere. www.myasthenia.org 800.541.5454

  16. Epidemiology of myasthenia gravis in Ontario, Canada.

    PubMed

    Breiner, Ari; Widdifield, Jessica; Katzberg, Hans D; Barnett, Carolina; Bril, Vera; Tu, Karen

    2016-01-01

    Incidence and prevalence estimates in myasthenia gravis have varied widely. Recent studies based on administrative health data have large sample sizes but lack rigorous validation of MG cases, and have not examined the North American population. Our aim was to explore trends in MG incidence and prevalence for the years 1996-2013 in the province of Ontario, Canada (population 13.5 million). We employed a previously validated algorithm to identify MG cases. Linking with census data allowed for the calculation of crude- and age/sex-standardized incidence and prevalence rates for the years 1996-2013. The regional distribution of MG cases throughout the province was examined. Mean age at the first myasthenia gravis encounter was 60.2 ± 17.1 years. In 2013, there were 3611 prevalent cases in Ontario, and the crude prevalence rate was 32.0/100,000 population. Age- and sex-standardized prevalence rates rose consistently over time from 16.3/100,000 (15.4-17.1) in 1996 to 26.3/100,000 (25.4-27.3) in 2013. Standardized incidence rates remained stable between 1996 (2.7/100,000; 95% CL 2.3-3.0) and 2013 (2.3/100,000; 2.1-2.6). Incidence was highest in younger women and older men, and geographic variation was evident throughout the province. In conclusion, this large epidemiological study shows rising myasthenia gravis prevalence with stable incidence over time, which is likely reflective of patients living longer, possibly due to improved disease treatment. Our findings provide accurate information on the Canadian epidemiology of myasthenia gravis and burden for health care resources planning for the province, respectively. PMID:26573434

  17. Ocular Myasthenia Gravis Associated With Thymic Amyloidosis.

    PubMed

    Chapman, Kristin O; Beneck, Debra M; Dinkin, Marc J

    2016-03-01

    A 45-year-old woman with ptosis and diplopia was found to have myasthenia gravis (MG) associated with amyloidosis of the thymus gland. Systemic MG is frequently associated with thymomas or thymic hyperplasia but has only once previously been reported in association with amyloidosis of the thymus. This case demonstrates that isolated ocular MG rarely may also be associated with amyloidosis of the thymus. PMID:25822660

  18. Acupuncture anesthesia in thymectomy on myasthenia gravis patients.

    PubMed

    Dong, S T; Nguyen, V T; Nguyen, V T; Vu, T A; Pham, M H

    1988-01-01

    Thymectomy is often successful as treatment for the autoimmune disease myasthenia gravis. One complication of the operation on such patients is respiratory difficulty especially post-operatively, due to interference with the already disturbed transmission of signals along damaged nerve-endings. Acupuncture anesthesia offers a solution to that problem. In this series of 90 patients, the results of operation under conventional general anesthesia were compared with those under acupuncture anesthesia. It was found that patients in the latter group suffered fewer complications. PMID:2898196

  19. Effectiveness of steroid treatment in myasthenia gravis: a retrospective study.

    PubMed

    Cosi, V; Citterio, A; Lombardi, M; Piccolo, G; Romani, A; Erbetta, A

    1991-07-01

    The records of 142 patients with generalized autoimmune myasthenia gravis who had been treated with steroids as the single immunosuppressive agent, collected at regular intervals, were employed for a retrospective evaluation. The effectiveness of treatment was assessed after 24 months; the data from the 6th and 12th months were also considered. After 24 months, 63.4% of the whole sample had improved (33.8% were in clinical or pharmacological remission); 13.4% were unchanged or had worsened and 22.3% had moved to a different immunosuppressive treatment. The rate of positive outcome was higher in patients over the age of 40 at disease onset. PMID:1927259

  20. Myasthenia gravis and masticatory muscle myositis in a dog

    PubMed Central

    Clooten, Jennifer K.; Woods, J. P.; Smith-Maxie, Laura L.

    2003-01-01

    A 21-month-old, castrated male Vizsla was presented for pelvic limb weakness, difficulty opening his mouth, ptyalism, voice change, and urinary incontinence. Myasthenia gravis and masticatory myositis were diagnosed. The unusual clinical findings, diagnosis, treatment, and case outcome are described, followed by a brief discussion of myasthenia gravis and masticatory myositis. PMID:12839242

  1. Steroids induce acetylcholine receptors on cultured human muscle: Implications for myasthenia gravis

    SciTech Connect

    Kaplan, I.; Blakely, B.T.; Pavlath, G.K.; Travis, M.; Blau, H.M. )

    1990-10-01

    Antibodies to the acetylcholine receptor (AChR), which are diagnostic of the human autoimmune disease myasthenia gravis, block AChR function and increase the rate of AChR degradation leading to impaired neuromuscular transmission. Steroids are frequently used to alleviate symptoms of muscle fatigue and weakness in patients with myasthenia gravis because of their well-documented immunosuppressive effects. The authors show here that the steroid dexamethasone significantly increases total surface AChRs on cultured human muscle exposed to myasthenia gravis sera. The results suggest that the clinical improvement observed in myasthenic patients treated with steroids is due not only to an effect on the immune system but also a direct effect on muscle. They propose that the identification and development of pharmacologic agents that augment receptors and other proteins that are reduced by human genetic or autoimmune disease will have broad therapeutic applications.

  2. Treatment of experimental myasthenia gravis with total lymphoid irradiation

    SciTech Connect

    de Silva, S.; Blum, J.E.; McIntosh, K.R.; Order, S.; Drachman, D.B.

    1988-07-01

    Total lymphoid irradiation (TLI) has been reported to be effective in the immunosuppressive treatment of certain human and experimental autoimmune disorders. We have investigated the effects of TLI in Lewis rats with experimental autoimmune myasthenia gravis (EAMG) produced by immunization with purified torpedo acetylcholine receptor (AChR). The radiation is given in 17 divided fractions of 200 rad each, and nonlymphoid tissues are protected by lead shielding. This technique suppresses the immune system, while minimizing side effects, and permits the repopulation of the immune system by the patient's own bone marrow cells. Our results show that TLI treatment completely prevented the primary antibody response to immunization with torpedo AChR, it rapidly abolished the ongoing antibody response in established EAMG, and it suppressed the secondary (anamnestic) response to a boost of AChR. No EAMG animals died during TLI treatment, compared with six control animals that died of EAMG. TLI produces powerful and prompt immunosuppression and may eventually prove useful in the treatment of refractory human myasthenia gravis.

  3. Development of myasthenia gravis after interferon alpha therapy.

    PubMed

    Gurtubay, I G; Morales, G; Aréchaga, O; Gállego, J

    1999-03-01

    Interferon (IFN) alpha is now used in the treatment of some malignant diseases and chronic viral hepatitis. There have been several reports of development of autoantibodies and autoimmune diseases or the deterioration of preexisting disorders in patients under treatment. We enclose a case of myasthenia gravis (MG) which developed after six weeks of treatment as fluctuating bilateral ptosis, intermittent diplopia, and mild weakness of limb and neck muscles. A test dose of edrophonium chloride was administered, resulting in improved muscle strength. Elevated anti acetylcholine receptor (AChR) antibody titer was found. Single fiber electromyography showed an increased jitter from extensor digitorum communis, frequently accompanied by transmission blocking. Repetitive electric 3 Hz stimulation of the abductor pollicis brevis muscle, revealed an abnormal decrement of 28% in compound motor action potential. Myasthenia gravis was diagnosed and the patient was given pyridostigmine, immunoglobulines and prednisone with benefit. Six months latter he developed an acute myasthenic crisis with severe respiratory failure and high anti AChR antibody titer. IFN-alpha can induce MG or simply manifests a preexisting subclinical disease, but otherwise its therapeutic efficacy in MG has been shown in experimental and clinical studies. Autoimmune mechanisms, as the release of different cytokines as IFN, by immunocompetent cells, may be involved in the pathogenesis of both MG and chronic active hepatitis. Autoantibody production against postsynaptic membrane structures by IFN-alpha could be the underlying pathophysiology. PMID:10207675

  4. Immunological relationship between acetylcholine receptor and thymus: a possible significance in myasthenia gravis.

    PubMed Central

    Aharonov, A; Tarrab-Hazdai, R; Abramsky, O; Fuchs, S

    1975-01-01

    A defined immunological cross-reaction was observed between acetylcholine receptor fraction from the electric eel, Electrophorus electricus, and two calf thymus fractions. The cross-reaction was demonstrated on the cellular level by means of the lymphocyte transformation technique, and on the humoral level, by means of the microcomplement fixation assay. In the human disease myasthenia gravis both acetylcholine receptor at the neuromuscular junction and the thymus are affected, probably by an autoimmune mechanism. The immunological cross-reaction between acetylcholine receptor and thymic components may explain the association between endplate and thymus disorders in myasthenia gravis. PMID:1055418

  5. Caudal epidural anesthesia for a 2-year old child with congenital myasthenia gravis.

    PubMed

    Calişkan, Esra; Koçum, Aysu; Sener, Mesut; Bozdoğan, Nesrin; Ariboğan, Aniş

    2008-10-01

    Myasthenia gravis is an autoimmune disease with antibodies directed against the acetylcholine receptor at the neuromuscular junction. Anesthetists have a special interest in myasthenia gravis because of its interaction with various anesthetic agents. Unlike adult myasthenic patients; very little report has been written about the anesthetic management in children, other than in relation to thymectomy. Although the use of caudal anesthesia in pediatric patients is common, have not seen any report concerning its use in a myasthenic child. In this case report, we represented a 2 year-old boy was performed caudal anesthesia for orchiopexy operation. He had presented difficulty in breathing, generalized weakness and droopy eyes due to congenital myasthenia gravis. In the operating room, following the routine monitoring, the patient was sedated with intravenous 1mg midazolam and 10 mg ketamine. Then caudal block was performed. 17 minutes later from the local anesthetic injection; operation was started and lasted 45 minutes. The patient did not require intraoperative supplemental analgesia and postoperative course was uneventful. Specific attention should be paid to voluntary and respiratory muscle strength in myasthenia gravis patients. Caudal anesthesia allowed airway control of myasthenia gravis patients without endotracheal intubations and muscle relaxant. In conclusion, we think that caudal anesthetic technique may be considered as a safe and suitable for the myasthenic child and it may represent a valid alternative to general anesthesia for these patients. PMID:19117157

  6. Myasthenia gravis: a careful perioperative anesthetic management of coronary artery bypass grafting.

    PubMed

    Kowalczyk, Michał; Nestorowicz, Andrzej; Stachurska, Katarzyna; Fijałkowska, Anna; Stążka, Janusz

    2015-06-01

    Nowadays, even hazardous cardiac surgery can be performed on patients with autoimmune diseases like myasthenia gravis. It requires a sensitive perioperative anesthetic approach especially in relation to nondepolarizing muscle relaxant administration. Myasthenic patients produce antibodies against the end-plate acetylcholine receptors causing muscle weakness and sensitivity to nondepolarizing muscle relaxants that could lead to respiratory failure. Perioperative nurse care is critical for uncomplicated course of treatment; therefore, apprehension of surgical procedure should be helpful on an everyday basis. We describe successful management without any pulmonary complications of two patients with myasthenia gravis undergoing coronary artery bypass grafting. In addition, antiacetylcholine receptor antibodies concentrations were evaluated during treatment time. In conclusion, we have found that reduced titrated doses of cisatracurium may be safely used in patients with myasthenia gravis undergoing cardiac surgery without anesthesia and respiratory-related complications. PMID:25943997

  7. A sodium channel myotonia due to a novel SCN4A mutation accompanied by acquired autoimmune myasthenia gravis.

    PubMed

    Kokunai, Yosuke; Goto, Keigo; Kubota, Tomoya; Fukuoka, Takaaki; Sakoda, Saburo; Ibi, Tohru; Doyu, Manabu; Mochizuki, Hideki; Sahashi, Ko; Takahashi, Masanori P

    2012-06-21

    Mutations of the voltage gated sodium channel gene (SCN4A) are responsible for non-dystrophic myotonia including hyperkalemic periodic paralysis, paramyotonia congenita, and sodium channel myotonia, as well as congenital myasthenic syndrome. In vitro functional analyses have demonstrated the non-dystrophic mutants to show a gain-of-function defect of the channel; a disruption of fast inactivation, an enhancement of activation, or both, while the myasthenic mutation presents a loss-of function defect. This report presents a case of non-dystrophic myotonia that is incidentally accompanied with acquired myasthenia. The patient presented a marked warm-up phenomenon of myotonia but the repeated short exercise test suggested mutations of the sodium channel. The genetic analysis identified a novel mutation, G1292D, of SCN4A. A functional study of the mutant channel revealed marked enhancement of activation and slight impairment of fast inactivation, which should induce muscle hyperexcitability. The effects of the alteration of channel function to the myasthenic symptoms were explored by using stimulation of repetitive depolarization pulses. A use-dependent channel inactivation was reduced in the mutant in comparison to normal channel, thus suggesting an opposing effect to myasthenia. PMID:22617007

  8. Myasthenia gravis and related disorders: Pathology and molecular pathogenesis.

    PubMed

    Ha, James C; Richman, David P

    2015-04-01

    Disorders affecting the presynaptic, synaptic, and postsynaptic portions of the neuromuscular junction arise from various mechanisms in children and adults, including acquired autoimmune or toxic processes as well as genetic mutations. Disorders include autoimmune myasthenia gravis associated with acetylcholine receptor, muscle specific kinase or Lrp4 antibodies, Lambert-Eaton myasthenic syndrome, nerve terminal hyperexcitability syndromes, Guillain Barré syndrome, botulism, organophosphate poisoning and a number of congenital myasthenic syndromes. This review focuses on the various molecular and pathophysiological mechanisms of these disorders, characterization of which has been crucial to the development of treatment strategies specific for each pathogenic mechanism. In the future, further understanding of the underlying processes may lead to more effective and targeted therapies of these disorders. This article is part of a Special Issue entitled: Neuromuscular Diseases: Pathology and Molecular Pathogenesis. PMID:25486268

  9. Animal models of myasthenia gravis: utility and limitations

    PubMed Central

    Mantegazza, Renato; Cordiglieri, Chiara; Consonni, Alessandra; Baggi, Fulvio

    2016-01-01

    Myasthenia gravis (MG) is a chronic autoimmune disease caused by the immune attack of the neuromuscular junction. Antibodies directed against the acetylcholine receptor (AChR) induce receptor degradation, complement cascade activation, and postsynaptic membrane destruction, resulting in functional reduction in AChR availability. Besides anti-AChR antibodies, other autoantibodies are known to play pathogenic roles in MG. The experimental autoimmune MG (EAMG) models have been of great help over the years in understanding the pathophysiological role of specific autoantibodies and T helper lymphocytes and in suggesting new therapies for prevention and modulation of the ongoing disease. EAMG can be induced in mice and rats of susceptible strains that show clinical symptoms mimicking the human disease. EAMG models are helpful for studying both the muscle and the immune compartments to evaluate new treatment perspectives. In this review, we concentrate on recent findings on EAMG models, focusing on their utility and limitations. PMID:27019601

  10. Ocular myasthenia gravis accompanied by anosmia.

    PubMed

    Chen, Ying; Wang, Li; Zhou, Li; Gao, Ying

    2016-02-01

    We report a case of ocular myasthenia gravis (MG) accompanied by anosmia. A 76-year-old man had idiopathic anosmia of 2-year duration. Four months before consultation, he began to have drooping in the right upper eyelid along with muscle soreness, distension, and pain in the nape. His tongue was dark-red with a thin and white coating; his pulse was wiry and slippery. According to Traditional Chinese Medicine, eyelid drooping and anosmia are the main signs of liver constraint and spleen deficiency. In Western Medicine, the diagnosis was ocular MG and idiopathic anosmia. Our patient, along with the literature, suggests that anosmia may be an early symptom before MG. MG accompanied by anosmia could be a special subtype of MG according to antibody production and symptoms. PMID:26946629

  11. Myasthenia Gravis and the Myasthenic Syndrome

    PubMed Central

    Herrmann, Christian

    1970-01-01

    Two disorders of neuromuscular transmission producing muscle weakness and easy fatigability which may confront the physician are myasthenia gravis and the myasthenic syndrome. The former has early symptoms and signs of oculobulbar and then extremity weakness with rapid decline of action potential and contractile strength with repetitive use and nerve-muscle stimulation. Anticholinesterases improve strength. The myasthenic syndrome has early symptoms and signs of pelvic girdle, pectoral girdle and proximal limb muscle weakness. This is worst when first starting to use or carry out nerve muscle stimulation in the rested muscles. It improves significantly for a time with use or on rapid stimulation, and then declines with continued activation. Deep tendon reflexes are sluggish or absent. Small cell carcinoma of the lung is often associated. Guanidine improves the strength. Other features and possible underlying mechanisms of the two disorders help to differentiate and treat them. PMID:5457513

  12. Neuromyelitis optica and myasthenia gravis in a young Nigerian girl.

    PubMed

    Balarabe, Salisu Abdullahi; Adamu, Mohammad Dantani; Watila, Musa Mamman; Jiya, Nma

    2015-01-01

    Neuromyelitis optica (NMO) and myasthenia gravis (MG) are rare autoimmune disorders. The coexistence of the two disorders, although rare, has been documented. This is a case report of a 16-year-old student who presented with recurrent episodes of transverse myelitis and optic neuritis, 8 years after diagnosis of MG. She presented with visual impairment, relapsing and remitting weakness, numbness and paraesthesia of her lower limbs, with bladder and bowel incontinence. Her examination revealed bilateral optic atrophy, spastic paraparesis of the lower limbs and patchy sensory loss up to thoracic level (T4-5). She had a positive acetylcholine receptor antibody, a positive aquaporin-4 antibody and chest CT finding of thymic enlargement. We therefore confirmed the previous diagnosis of MG and performed a recent diagnosis of background NMO. A high index of suspicion is needed to make a diagnosis of this rare coexistence of NMO and MG in resource-limited settings such as Nigeria. PMID:26338241

  13. Idiopathic Pulmonary Fibrosis and Myasthenia Gravis: An Unusual Association

    PubMed Central

    Chogtu, Bharti; Malik, Daliparty Vasudev

    2016-01-01

    Idiopathic Pulmonary Fibrosis (IPF) is a chronic fibrosing lung condition with high morbidity and mortality, accounting for about 25% of the cases of interstitial lung diseases. It usually has a progressive course resulting in death due to respiratory failure. Myasthenia Gravis (MG) is an autoimmune neuromuscular disease, caused by antibody mediated activity against acetylcholine receptor at the neuromuscular junction. It is characterized by fluctuating muscle weakness and fatigue. Extensive literature search did not reveal any case report of an association between these two conditions. Here we present a case of a patient with IPF who also developed MG. The diagnosis of IPF was based on High Resolution Computed Tomography (HRCT) of the lung and that of MG was based on clinical criteria and electrophysiological testing. The case was successfully managed. PMID:27190866

  14. Idiopathic Pulmonary Fibrosis and Myasthenia Gravis: An Unusual Association.

    PubMed

    Chogtu, Bharti; Malik, Daliparty Vasudev; Magazine, Rahul

    2016-04-01

    Idiopathic Pulmonary Fibrosis (IPF) is a chronic fibrosing lung condition with high morbidity and mortality, accounting for about 25% of the cases of interstitial lung diseases. It usually has a progressive course resulting in death due to respiratory failure. Myasthenia Gravis (MG) is an autoimmune neuromuscular disease, caused by antibody mediated activity against acetylcholine receptor at the neuromuscular junction. It is characterized by fluctuating muscle weakness and fatigue. Extensive literature search did not reveal any case report of an association between these two conditions. Here we present a case of a patient with IPF who also developed MG. The diagnosis of IPF was based on High Resolution Computed Tomography (HRCT) of the lung and that of MG was based on clinical criteria and electrophysiological testing. The case was successfully managed. PMID:27190866

  15. Myasthenia gravis and invasive thymoma with multiple intracranial metastases.

    PubMed

    Koç, Filiz; Yerdelen, Deniz; Sarica, Yakup

    2003-06-01

    Myasthenia gravis (MG) is an autoimmune disease. Approximately 15% of patients with MG have thymoma. Approximately 30% to 40% of them are invasive. A 26-year-old man was admitted with cough and difficulty breathing. He had transsternal thymectomy resulting from MG accompanied by thymoma 6 years previously. Thorax computerized tomography (CT) scans showed metastases to the extra-mediastinum. Diagnosis of invasive thymoma was made by CT-guided biopsy. A PAC regimen (cisplatin, doxorubicin, cyclophosphamide) and radiotherapy were added to MG treatment. Ten months later, he presented again with headache, weakness, and difficulty swallowing. We determined that he had intracranial multiple metastases. He was hospitalized. Cerebral multiple metastases were evaluated as inoperable. However, he died of transtentorial herniation after 1 month. This MG case accompanied by invasive thymoma with multiple intracranial metastases is discussed. PMID:19078711

  16. Genetic basis of myasthenia gravis - a comprehensive review.

    PubMed

    Avidan, Nili; Le Panse, Rozen; Berrih-Aknin, Sonia; Miller, Ariel

    2014-08-01

    Myasthenia gravis (MG) is a rare autoimmune disease characterized by the production of autoantibodies against proteins of the postsynaptic membrane in the neuromuscular junction. The estimated number of MG patients is steadily increasing, and it had more than doubled in the last 20 years. Monozygotic MG twin concordance is estimated to be about 35% supporting the central role of environmental factors in MG etiology. Epigenetics, presume to be the mechanistic link between environmental and genetic risk factors in disease development, provides support for specific microRNAs associated with MG. Genetic studies have mainly pointed at specific HLA alleles implicated in MG susceptibility, however recently both TNFAIP3-interacting protein 1 (TNIP1) and tyrosine phosphatase non-receptor 22 (PTPN22) were indicated to be associated with MG in a GWAS study. A gender bias was observed for SNPs in the HLA-locus, suggesting female-specific alleles have an increase risk for MG. Moreover, sex hormones play a pivotal role in the gender bias in autoimmunity in general and in MG in particular. Hence the genetic basis of gender bias might be highly pertinent to MG and deserves further characterization. Pathway-based analyses that combine information across multiple genes into a limited number of molecular networks have been found to be a powerful approach. Both regulatory T-cell (Treg) differentiation and NF-κB signaling pathway have been shown to have relevance to MG pathophysiology. Hence studies centered around two pathways might be a fruitful approach to identify additional polymorphisms associated with myasthenia gravis. PMID:24361103

  17. Inhibitory effect of alpha-fetoprotein on the binding of myasthenia gravis antibody to acetylcholine receptor.

    PubMed Central

    Brenner, T; Beyth, Y; Abramsky, O

    1980-01-01

    The binding of myasthenia gravis antibody acetylcholine receptor (AcChoR) as measured in vitro by Radioimmunoassay with 125I-labeled alpha-bungarotoxin (alpha-BuTx), can be blocked by amniotic fluid, maternal serum, and umbilical cord serum. This inhibitory effect is due to alpha-fetoprotein present in high concentrations in amniotic fluid and serum, as shown by: (i) selective removal of several components from amniotic fluid and serum; (ii) selective addition of different components present in amniotic fluid and serum, including alpha-fetoprotein, to be radioimmunoassay; (iii) correlation between the inhibitory effect of both amniotic fluid and serum and between the amounts of alpha-fetoprotein they contain; (iv) blocking of the alpha-fetoprotein in vitro suggests a similar effect in vivo in pregnant women with myasthenia gravis. This effect may explain in part the variability in the development of neonatal myasthenia gravis in the babies, due to transplacental transfer of maternal anti-AcChoR antibody, only after delivery and only in the minority of the cases. It also may explain the appearnace of remissions in females with myasthenia gravis during the second and third trimesters of pregnancy. Similar phenomena observed during pregnancy in other autoimmune and immunopathogenic diseases also might be attributed to activity of alpha-fetoprotein. PMID:6158053

  18. Differential Diagnosis of Hallucinations in a Patient with Myasthenia Gravis

    PubMed Central

    Hizem, Yosr; Ben Djebara, Mouna; Kacem, Imen; Gargouri, Amina; Gouider, Riadh

    2013-01-01

    We present the case of a 63-year-old woman with comorbidity of myasthenia gravis and psychosis. Different diagnostic hypotheses based on a review of the literature are discussed. A protracted history of physical spousal abuse, patient symptoms, and results of different investigations allowed us to conclude that the patient had a form of posttraumatic stress disorder with secondary psychotic features. Psychosis due to myasthenia gravis is rarely seen, and it remains unclear what is the pathophysiology, if any, for such an association. The present case highlights the difficulties the physician faces in disentangling psychosis as a potential manifestation of myasthenia gravis itself versus being caused by a medical side effect of treatment, or psychosis due to a distinct co-occurring neurologic or psychiatric condition. PMID:24307978

  19. [Course and treatment of myasthenia gravis during pregnancy].

    PubMed

    Klehmet, J; Dudenhausen, J; Meisel, A

    2010-08-01

    Pregnancy and family planning issues are frequent concerns in the medical care of patients with myasthenia gravis since disease onset often coincides with the life period which is decisive in this respect. Although pregnancy, delivery and breastfeeding represent special circumstances in these patients, they are not associated with higher risks of complications compared to normal pregnancy, delivery and postpartum period. Frequently asked questions regard the course of pregnancy as well as the impact of the disease and particularly medical treatment on pregnancy and the foetus or neonate. Great significance is attached to the mode of delivery since it is still widely accepted that patients with myasthenia gravis have to deliver per elective caesarean section. This paper gives an overview and provides a basis for the medical care and individual counselling of patients with myasthenia gravis who want to start a family or are already pregnant. PMID:20411231

  20. Congenital myasthenic syndrome due to mutation in CHRNE gene with clinical worsening and thymic hyperplasia attributed to association with autoimmune-myasthenia gravis.

    PubMed

    Santos, Ernestina; Moreira, Isabel; Coutinho, Ester; Gonçalves, Guilherme; Lopes, Carlos; Lopes Lima, José; Leite, M Isabel

    2015-12-01

    We report a patient with congenital myasthenic syndrome (CMS) due to mutation in CHRNE with symptoms since the age of 4; mild to moderate fatigable weakness involved mainly ocular, bulbar and limb muscles; functional impact of the disease in their development and physical activity was modest. By the age of 34, the patient experienced gradual worsening of fatigue with dyspnoea and pronounced limb weakness, requiring significant increase of pyridostigmine. Further, a remarkable and sustained clinical improvement followed thymectomy with hyperplastic thymus. Despite of the absence of detectable antibodies to acetyl-choline receptor (AChR) (including clustered-AChR), muscle-specific kinase and low-density lipoprotein receptor-related protein-4 antibodies in the serum obtained nine years after thymectomy, the clinical, genetic and histological features are in keeping with the extremely rare association of two rare neuromuscular junction disorders - CMS and myasthenia gravis (MG). The inexistence of other conditions that could potentially associate with thymic hyperplasia also supports the diagnosis of MG. PMID:26363966

  1. T and B lymphocytes in myasthenia gravis.

    PubMed Central

    Itoyama, Y; Kawanami, S; Goto, I; Kuroiwa, Y

    1979-01-01

    Peripheral blood lymphocytes from seventeen non-thymectomized and nine thymectomized patients with myasthenia gravis (MG) and thirteen healthy controls were examined for the presence of surface markers characteristic of T and B lymphocytes by rosette formation with sheep red blood cells (SRBC). T cells were identified by their capacity to spontaneously form rosettes with SRBCs. The percentage of B lymphocytes was determined by the erythrocyte antibody complement (EAC) rosette-forming test. The EAC complex was prepared with either whole rabbit anti-SRBC serum or with the IgM fraction of rabbit anti-SRBC serum. The two kind of erythrocyte complement rosette-forming cells (EAC-RFC) are designated erythrocyte-haemolysin-complement RFC (EA(H)C-RFC), and erythrocyte-IgM-complement RFC (EA(M)C-RFC). The percentage of total lymphocytes and T cells was not altered in MG patients. The percentage of 'active' T cells, which have been considered to be more actively involved in cellular immunity, was also similar in MG patients and controls. A significant increase in EA(H)C-RFC occurred in both thymectomized and non-thymectomized MG patients, while in B cells detected by EA(M)C-RFC no alterations were found. The increase in EA(H)C-RFC in lymphocytes from MG patients may be due to an increase in the 19S antibody-forming B lymphocytes or to an increase in T cells which have Fc receptors on their surface. PMID:315844

  2. Myasthenia Gravis Presentation After a Cervical Laminectomy With Fusion.

    PubMed

    Deters, Darlene; Fowler, Stephanie L; Orozco, Raymundo; Smith, Patrick R; Spurlock, Shelby; Blackmon, Darlene; Thomas, Samantha

    2016-01-01

    Myasthenia gravis is a chronic neuromuscular disorder that causes skeletal muscle weakness. Typically, myasthenia gravis affects the ocular, bulbar, neck, proximal limbs, and respiratory muscles. Although the presentation is typically observed with complaints of vision and bulbar symptoms such as diplopia, dystonia, and dysphagia, this article presents a case study of an elderly man with a history of increasing upper extremity weakness with complaints of worsening hand dexterity and intermittent episodes of expressive aphasia. After cervical laminectomy with fusion, this gentleman was admitted to the medical intensive care unit, in a complete myasthenic crisis. PMID:27258955

  3. [Determination of prognostic factors in surgical treatment of myasthenia gravis].

    PubMed

    Schnorrer, M; Hraska, V; Spalek, P; Cársky, S

    1999-05-01

    The authors evaluated, using statistical analysis, the importance of prognostic factors in patients subjected to thymectomy on account of myasthenia gravis. The results revealed a better prognosis of the disease, if the history was less than 6 months, preoperative treatment less than 1.5 years, a histological finding of thymus hyperplasia, second clinical stage according to Ossermann and the patients age below 30 years. From the statistical analysis ensues that the prognosis of myasthenia gravis is more favourable when the case-history is shorter as a result of rapid diagnosis and when preoperative treatment is reduced to a minimum. PMID:10510623

  4. Paraneoplastic pemphigus and myasthenia gravis, associated with inflammatory pseudotumor-like follicular dendritic cell sarcoma: response to rituximab.

    PubMed

    Wang, Lifang; Deng, Hui; Mao, Mei

    2016-08-01

    Paraneoplastic pemphigus (PNP) is an autoimmune blistering disease associated with neoplasms. The disease is most commonly of lymphoproliferative origin and presents high mortality. We describe a patient with PNP and myasthenia gravis associated with inflammatory pseudotumor-like follicular dendritic cell sarcoma, as well as the response to rituximab. PMID:27525088

  5. Determinants of quality of life in Brazilian patients with myasthenia gravis

    PubMed Central

    Mourão, Aline Mansueto; Gomez, Rodrigo Santiago; Barbosa, Luiz Sergio Mageste; da Silva Freitas, Denise; Comini-Frota, Elizabeth Regina; Kummer, Arthur; Lemos, Stella Maris Aguiar; Teixeira, Antonio Lucio

    2016-01-01

    OBJECTIVES: The aims of the current study were 1) to evaluate the reliability and validity of the Brazilian version of the 15-item Myasthenia Gravis Quality of Life Scale and 2) to investigate the quality of life of Brazilian patients with myasthenia gravis and its determinants. METHODS: This cross-sectional study included 69 patients with myasthenia gravis who underwent neurological evaluation and completed questionnaires regarding quality of life (the 36-item Short Form of the Medical Outcomes Study and the 15-item Myasthenia Gravis Quality of Life Scale), anxiety and depressive symptoms. RESULTS: The Brazilian version of the 15-item Myasthenia Gravis Quality of Life Scale showed high internal consistency and good concurrent validity with the 36-item Short Form of the Medical Outcomes Study and its subscales. Determinants of quality of life in Brazilian patients with myasthenia gravis included the current status of myasthenia gravis as assessed by the Myasthenia Gravis Composite, the current prednisone dose and the levels of anxiety and depression. CONCLUSION: The Brazilian version of the 15-item Myasthenia Gravis Quality of Life Scale is a valid instrument. Symptom severity, prednisone dosage and anxiety and depression levels impact the quality of life of patients with myasthenia gravis. PMID:27464292

  6. Myasthenia gravis and congenital myasthenic syndromes in dogs and cats: A history and mini-review.

    PubMed

    Shelton, G Diane

    2016-06-01

    Myasthenia gravis (MG) is a disorder of neuromuscular transmission in which muscle weakness results from an autoantibody mediated depletion of acetylcholine receptors (AChRs) at the neuromuscular junction. Myasthenia gravis occurs spontaneously in dogs and cats, and as in human MG, an autoimmune response against nicotinic AChRs has been demonstrated and autoantibodies against AChRs implicated in the pathogenesis. While both species are affected with MG, there are distinct differences in clinical presentations and frequency of spontaneous remission. Congenital myasthenic syndromes (CMSs) are hereditary disorders of neuromuscular transmission resulting in structural or functional defects of the neuromuscular junction. The clinical presentation and pathogenesis of a CMS in Jack Russell terriers was first described in the 1970's and 1980s and has since been reported in a few other breeds. Mutations have been reported in CHRNE, COLQ and CHAT in canine CMS. A form of COLQ deficient CMS has recently been reported in cats. PMID:27080328

  7. Muscle-Specific Receptor Tyrosine Kinase (MuSK) Myasthenia Gravis.

    PubMed

    Hurst, Rebecca L; Gooch, Clifton L

    2016-07-01

    Autoimmune myasthenia gravis (MG) is the prototypic, antibody-mediated neuromuscular disease and is characterized by a decrease in the number of functional acetylcholine receptors (AChR) within the muscle end plate zone of the neuromuscular junction (NMJ). Although the pathophysiology of AChR-mediated myasthenia gravis has been extensively studied over the last 40 years since its original description by Patrick and Lindstrom (Science 180:871-872, 1973), less is known about the much more recently described muscle-specific kinase (MuSK) antibody-mediated MG. MuSK-MG has features clinically distinct from Ach-R MG, as well as a different pattern of response to treatment and a unique immunopathogenesis. PMID:27170368

  8. The effect of cholinesterase inhibitors of SFEMG in myasthenia gravis.

    PubMed

    Massey, J M; Sanders, D B; Howard, J F

    1989-02-01

    We report four patients with myasthenia gravis (MG) in whom single-fiber electromyography (SFEMG) jitter measurements were normal in some muslces while they were taking pyridostigmine and became abnormal 2-14 days after the medication was discontinued. When the abnormality of neuromuscular transmission in MG is mild, cholinesterase inhibitors may mask the findings of increased jitter on SFEMG. PMID:2540433

  9. Ocular myasthenia gravis after D-penicillamine administration.

    PubMed Central

    Katz, L J; Lesser, R L; Merikangas, J R; Silverman, J P

    1989-01-01

    A 68-year-old black woman who was put on D-penicillamine therapy (250-500 mg per day, total dose 15 g) for rheumatoid arthritis developed ocular myasthenia gravis. Two weeks after she discontinued D-penicillamine her signs and symptoms cleared with no other treatment. Review of previous cases and possible immunological mechanisms are discussed. PMID:2692700

  10. Autoantibodies to Agrin in Myasthenia Gravis Patients

    PubMed Central

    Bealmear, Beverly; Ragheb, Samia; Xiong, Wen-Cheng; Lewis, Richard A.; Lisak, Robert P.; Mei, Lin

    2014-01-01

    To determine if patients with myasthenia gravis (MG) have antibodies to agrin, a proteoglycan released by motor neurons and is critical for neuromuscular junction (NMJ) formation, we collected serum samples from 93 patients with MG with known status of antibodies to acetylcholine receptor (AChR), muscle specific kinase (MuSK) and lipoprotein-related 4 (LRP4) and samples from control subjects (healthy individuals and individuals with other diseases). Sera were assayed for antibodies to agrin. We found antibodies to agrin in 7 serum samples of MG patients. None of the 25 healthy controls and none of the 55 control neurological patients had agrin antibodies. Two of the four triple negative MG patients (i.e., no detectable AChR, MuSK or LRP4 antibodies, AChR-/MuSK-/LRP4-) had antibodies against agrin. In addition, agrin antibodies were detected in 5 out of 83 AChR+/MuSK-/LRP4- patients but were not found in the 6 patients with MuSK antibodies (AChR-/MuSK+/LRP4-). Sera from MG patients with agrin antibodies were able to recognize recombinant agrin in conditioned media and in transfected HEK293 cells. These sera also inhibited the agrin-induced MuSK phosphorylation and AChR clustering in muscle cells. Together, these observations indicate that agrin is another autoantigen in patients with MG and agrin autoantibodies may be pathogenic through inhibition of agrin/LRP4/MuSK signaling at the NMJ. PMID:24632822

  11. Autoantibodies to agrin in myasthenia gravis patients.

    PubMed

    Zhang, Bin; Shen, Chengyong; Bealmear, Beverly; Ragheb, Samia; Xiong, Wen-Cheng; Lewis, Richard A; Lisak, Robert P; Mei, Lin

    2014-01-01

    To determine if patients with myasthenia gravis (MG) have antibodies to agrin, a proteoglycan released by motor neurons and is critical for neuromuscular junction (NMJ) formation, we collected serum samples from 93 patients with MG with known status of antibodies to acetylcholine receptor (AChR), muscle specific kinase (MuSK) and lipoprotein-related 4 (LRP4) and samples from control subjects (healthy individuals and individuals with other diseases). Sera were assayed for antibodies to agrin. We found antibodies to agrin in 7 serum samples of MG patients. None of the 25 healthy controls and none of the 55 control neurological patients had agrin antibodies. Two of the four triple negative MG patients (i.e., no detectable AChR, MuSK or LRP4 antibodies, AChR-/MuSK-/LRP4-) had antibodies against agrin. In addition, agrin antibodies were detected in 5 out of 83 AChR+/MuSK-/LRP4- patients but were not found in the 6 patients with MuSK antibodies (AChR-/MuSK+/LRP4-). Sera from MG patients with agrin antibodies were able to recognize recombinant agrin in conditioned media and in transfected HEK293 cells. These sera also inhibited the agrin-induced MuSK phosphorylation and AChR clustering in muscle cells. Together, these observations indicate that agrin is another autoantigen in patients with MG and agrin autoantibodies may be pathogenic through inhibition of agrin/LRP4/MuSK signaling at the NMJ. PMID:24632822

  12. Myasthenia gravis - autoantibody characteristics and their implications for therapy.

    PubMed

    Gilhus, Nils Erik; Skeie, Geir Olve; Romi, Fredrik; Lazaridis, Konstantinos; Zisimopoulou, Paraskevi; Tzartos, Socrates

    2016-05-01

    Myasthenia gravis (MG) is an autoimmune disorder caused by autoantibodies that target the neuromuscular junction, leading to muscle weakness and fatigability. Currently available treatments for the disease include symptomatic pharmacological treatment, immunomodulatory drugs, plasma exchange, thymectomy and supportive therapies. Different autoantibody patterns and clinical manifestations characterize different subgroups of the disease: early-onset MG, late-onset MG, thymoma MG, muscle-specific kinase MG, low-density lipoprotein receptor-related protein 4 MG, seronegative MG, and ocular MG. These subtypes differ in terms of clinical characteristics, disease pathogenesis, prognosis and response to therapies. Patients would, therefore, benefit from treatment that is tailored to their disease subgroup, as well as other possible disease biomarkers, such as antibodies against cytoplasmic muscle proteins. Here, we discuss the different MG subtypes, the sensitivity and specificity of the various antibodies involved in MG for distinguishing between these subtypes, and the value of antibody assays in guiding optimal therapy. An understanding of these elements should be useful in determining how to adapt existing therapies to the requirements of each patient. PMID:27103470

  13. Treatment of myasthenia gravis with high-dose intravenous immunoglobulin.

    PubMed

    Cosi, V; Lombardi, M; Piccolo, G; Erbetta, A

    1991-08-01

    We treated 37 patients affected by autoimmune generalized myasthenia gravis (MG) with high-dose intravenous gammaglobulin (HDIVIg), 400 mg/kg per day on 5 consecutive days. A one-degree improvement of Oosterhuis global clinical classification of myasthenic severity (OGCCMS), the disappearance of bulbar involvement or both were recorded 12 days after the beginning of the treatment in 70.3% of the patients and persisted up to 60 days in 58.7%. A two-degree improvement of OGCCMS was recorded in 54.1% of the patients and it was maintained up to 60 days in 37.8%. The percentage of improvement did not significantly differ between patients entering the treatment in a long-standing, drug-refractory stationary phase of the illness (n = 26) and patients who received HDIVIg in an acute phase of MG (n = 11). None of the patients experienced side effects. Our data indicates that HDIVIg is an interesting, virtually riskless therapeutic choice for MG patients, and allows the planning of a controlled trial versus plasma-exchange. PMID:1950455

  14. Subcutaneous Immunoglobulin Therapy in the Chronic Management of Myasthenia Gravis: A Retrospective Cohort Study

    PubMed Central

    Bourque, P. R.; Pringle, C. E.; Cameron, W.; Cowan, J.; Chardon, J. Warman

    2016-01-01

    Background Immunoglobulin therapy has become a major treatment option in several autoimmune neuromuscular disorders. For patients with Myasthenia Gravis (MG), intravenous immunoglobulin (IVIg) has been used for both crisis and chronic management. Subcutaneous Immunoglobulins (SCIg), which offer the advantage of home administration, may be a practical and effective option in chronic management of MG. We analyzed clinical outcomes and patient satisfaction in nine cases of chronic disabling MG who were either transitioned to, or started de novo on SCIg. Methods and Findings This was a retrospective cohort study for the period of 2015–2016, with a mean follow-up period of 6.8 months after initiation of SCIg. All patients with MG treated with SCIg at the Ottawa Hospital, a large Canadian tertiary hospital with subspecialty expertise in neuromuscular disorders were included, regardless of MG severity, clinical subtype and antibody status. The primary outcome was MG disease activity after SCIg initiation. This outcome was measured by 1) the Myasthenia Gravis Foundation of America (MGFA) clinical classification, and 2) subjective scales of disease activity including the Myasthenia Gravis activities of daily living profile (MG-ADL), Myasthenia Gravis Quality-of-life (MG-QOL 15), Visual Analog (VA) satisfaction scale. We also assessed any requirement for emergency department visits or hospitalizations. Safety outcomes included any SCIg related complication. All patients were stable or improved for MGFA class after SCIg initiation. Statistically significant improvements were documented in the MG-ADL, MG-QOL and VAS scales. There were no exacerbations after switching therapy and no severe SCIg related complications. Conclusions SCIg may be a beneficial therapy in the chronic management of MG, with favorable clinical outcome and patient satisfaction results. PMID:27490101

  15. The mechanism of acetylcholine receptor in binding MuSK in myasthenia gravis and the role of HSP90 molecular chaperone

    PubMed Central

    Chen, Rongbo; Chen, Siqia; Liao, Juan; Chen, Xiaopu; Xu, Xiaoling

    2016-01-01

    As an autoimmune disease, myasthenia gravis is caused by the dysfunction of neural transmission. Acetylcholine is known to exert its function after entering into synaptic cleft through binding onto postsynaptic membrane. The role of acetylcholine in binding MuSK in myasthenia gravis, however, remains unknown. A total of 38 myasthenia gravis patients and 27 healthy controls were included in this study for the detection of the expression of MuSK using immunofluorescent method. Expression of both MuSK and interleukin-6 (IL-6) were measured by Western blot, followed by the correlation analysis between heat shock protein 90 (HSP90) and IL-6 which were measured by enzyme-linked immunosorbent assay (ELISA). In myasthenia gravis patients, MuSK was co-localized with acetylcholine at the postsynaptic membrane. Such accumulation of MuSK, however, did not occur in normal people. Meanwhile we also observed elevated expression of IL-6 in myasthenia gravis patients (p<0.05). ELISA assay showed higher expression of HSP90 in patients. Further signaling pathway screening revealed the activation of IL-6-mediated pathways including STAT3 and SPH2. In conclusion, MuSK was co-localized with acetylcholine in myasthenia gravis patients, with elevated expression. HSP90 in disease people can activate IL-6 mediated signaling pathways. PMID:27186300

  16. Future perspectives in target-specific immunotherapies of myasthenia gravis

    PubMed Central

    Dalakas, Marinos C.

    2015-01-01

    Myasthenia gravis (MG) is an autoimmune disease caused by complement-fixing antibodies against acetylcholine receptors (AChR); antigen-specific CD4+ T cells, regulatory T cells (Tregs) and T helper (Th) 17+ cells are essential in antibody production. Target-specific therapeutic interventions should therefore be directed against antibodies, B cells, complement and molecules associated with T cell signaling. Even though the progress in the immunopathogenesis of the disease probably exceeds any other autoimmune disorder, MG is still treated with traditional drugs or procedures that exert a non-antigen specific immunosuppression or immunomodulation. Novel biological agents currently on the market, directed against the following molecular pathways, are relevant and specific therapeutic targets that can be tested in MG: (a) T cell intracellular signaling molecules, such as anti-CD52, anti-interleukin (IL) 2 receptors, anti- costimulatory molecules, and anti-Janus tyrosine kinases (JAK1, JAK3) that block the intracellular cascade associated with T-cell activation; (b) B cells and their trophic factors, directed against key B-cell molecules; (c) complement C3 or C5, intercepting the destructive effect of complement-fixing antibodies; (d) cytokines and cytokine receptors, such as those targeting IL-6 which promotes antibody production and IL-17, or the p40 subunit of IL-12/1L-23 that affect regulatory T cells; and (e) T and B cell transmigration molecules associated with lymphocyte egress from the lymphoid organs. All drugs against these molecular pathways require testing in controlled trials, although some have already been tried in small case series. Construction of recombinant AChR antibodies that block binding of the pathogenic antibodies, thereby eliminating complement and antibody-depended-cell-mediated cytotoxicity, are additional novel molecular tools that require exploration in experimental MG. PMID:26600875

  17. Future perspectives in target-specific immunotherapies of myasthenia gravis.

    PubMed

    Dalakas, Marinos C

    2015-11-01

    Myasthenia gravis (MG) is an autoimmune disease caused by complement-fixing antibodies against acetylcholine receptors (AChR); antigen-specific CD4+ T cells, regulatory T cells (Tregs) and T helper (Th) 17+ cells are essential in antibody production. Target-specific therapeutic interventions should therefore be directed against antibodies, B cells, complement and molecules associated with T cell signaling. Even though the progress in the immunopathogenesis of the disease probably exceeds any other autoimmune disorder, MG is still treated with traditional drugs or procedures that exert a non-antigen specific immunosuppression or immunomodulation. Novel biological agents currently on the market, directed against the following molecular pathways, are relevant and specific therapeutic targets that can be tested in MG: (a) T cell intracellular signaling molecules, such as anti-CD52, anti-interleukin (IL) 2 receptors, anti- costimulatory molecules, and anti-Janus tyrosine kinases (JAK1, JAK3) that block the intracellular cascade associated with T-cell activation; (b) B cells and their trophic factors, directed against key B-cell molecules; (c) complement C3 or C5, intercepting the destructive effect of complement-fixing antibodies; (d) cytokines and cytokine receptors, such as those targeting IL-6 which promotes antibody production and IL-17, or the p40 subunit of IL-12/1L-23 that affect regulatory T cells; and (e) T and B cell transmigration molecules associated with lymphocyte egress from the lymphoid organs. All drugs against these molecular pathways require testing in controlled trials, although some have already been tried in small case series. Construction of recombinant AChR antibodies that block binding of the pathogenic antibodies, thereby eliminating complement and antibody-depended-cell-mediated cytotoxicity, are additional novel molecular tools that require exploration in experimental MG. PMID:26600875

  18. Multidisciplinary treatment for prepubertal juvenile myasthenia gravis with crisis.

    PubMed

    Hirata, Yusuke; Inoue, Masayoshi; Nabatame, Shin; Okumura, Meinoshin; Ozono, Keiichi

    2016-08-01

    The management of juvenile myasthenia gravis (MG) remains controversial. We report herein the case of a 12-year-old girl with prepubertal juvenile MG with respiratory crisis who underwent thymectomy following methylprednisolone pulse therapy. The patient initially developed progressively worsening fatigability, eyelid ptosis, and diplopia, followed by worsening generalized weakness, dysphagia, and dyspnea. Even after i.v. immunoglobulin, the patient presented with rapid onset of severe dyspnea requiring respiratory support with mechanical ventilation and was graded as Myasthenia Gravis Foundation of America class V. After a course of i.v. methylprednisolone pulse therapy, successful control of respiratory crisis was achieved, and trans-sternal thymectomy was performed. Partial remission was achieved postoperatively with oral pyridostigmine without immunosuppressive agents such as steroids or calcineurin inhibitors for 18 months after thymectomy. Early thymectomy following induction methylprednisolone pulse therapy might be a treatment option for prepubertal juvenile MG with severe respiratory crisis. PMID:27324449

  19. Myasthenia gravis on the Dutch antilles: an epidemiological study.

    PubMed

    Holtsema, H; Mourik, J; Rico, R E; Falconi, J R; Kuks, J B; Oosterhuis, H J

    2000-12-01

    We carried out an epidemiological study on the prevalence and annual incidence of myasthenia gravis on tropical islands Curaçao and Aruba in the period 1980-1995. Twenty-one patients (seven men and 14 women) were identified. The point prevalence increased from 29 per million in 1980 to about 70 per million in 1990-1995; the annual incidence over the total period was 4.7 per million. The female:male ratio was 2:1; purely ocular cases (2/21) comprised 9.5% and thymomas (4/21), 19%. These data are in accordance with most other epidemiological studies in non-tropical areas. No other studies on myasthenia gravis in tropical areas have been reported. PMID:11154803

  20. Thymic carcinoma in myasthenia gravis developing years after thymectomy.

    PubMed

    Katzberg, Hans D; Miller, Robert G; Katz, Jonathan

    2009-07-01

    We report two patients with myasthenia gravis (MG) who underwent thymectomy but developed thymic carcinoma years after the initial surgery. In one patient, the initial thymic pathology was normal, whereas the other had an encapsulated benign thymoma that was found only on pathological assessment. These cases demonstrate that MG may occur as part of a "new" paraneoplastic syndrome even after thymectomy. The late appearance of metastatic thymoma raises questions about monitoring for these patients. PMID:19533649

  1. MuSK-antibody positive myasthenia gravis: questions from the clinic.

    PubMed

    Sanders, Donald B; Juel, Vern C

    2008-09-15

    Clinical vignettes are presented of five patients with MuSK-antibody positive myasthenia gravis, each of which demonstrates a diagnostic or therapeutic issue that is unique to or characteristic of this condition. Consideration of these issues leads to questions, many of which are unanswered at this time, about the immunopathology and management of this subset of myasthenia gravis. PMID:18684517

  2. [Surgical treatment of myasthenia gravis in children].

    PubMed

    Iudin, Ia B; Kogan, O G; Prokopenko, Iu D; Klepikov, I I; Vusik, G V; Fedorov, K K; Ivanov, V V; Diupin, V A; Merzeniuk, O S

    1989-11-01

    The article deals with the treatment of myasthenia in 33 children whose ages ranged from 3 to 15 years. Myasthenia of moderate severity was diagnosed in 14, severe in 15, and extremely severe in 2 children. To make a precise diagnosis, loading, neostigmine methylsulfate, cold, and D-tubocurarine tests were conducted. Thymectomy was performed in 32 patients. The operation was carried out through a T-shaped sternotomy approach. Thymogenic myasthenia was verified in 31 patients and thymomogenic only in one patient. There were no fatal outcomes. The late-term results were studied in 12 patients in follow-up periods of 3 to 6 years. Adaptational activity of the patients, anticholinesterase agents and the results of stimulant electric myography served as the criterion in appraising the late-term results. Modern diagnostic methods and surgical intervention ensure a favourable result in 75% of patients. PMID:2615272

  3. Tacrolimus for myasthenia gravis: a clinical study of 212 patients.

    PubMed

    Ponseti, José M; Gamez, Josep; Azem, Jamal; López-Cano, Manuel; Vilallonga, Ramón; Armengol, Manuel

    2008-01-01

    Tacrolimus is a macrolide T cell immunomodulator that is used in myasthenia gravis (MG) patients to affect muscle contraction (ryanodine receptor by modulating intracellular calcium-release channels and increasing muscular strength), glucocorticoid receptors (increasing intracellular concentration of steroids and blocking the steroid export mechanism), and an increase in T cell apoptosis. In this study, we report the results of low-dose tacrolimus (0.1 mg/kg/day) treatment in 212 MG patients. There were 110 thymectomized, cyclosporine- and prednisone-dependent patients; 68 thymectomized patients who started tacrolimus early postoperatively (24 h after operation); and 34 patients over 60 years old with nonthymomatous generalized MG or in whom thymectomy was contraindicated. The mean follow-up time was 49.3 +/- 18.1 months. Muscular strength showed an increase of 23% after 1 month of treatment and 29% at the end of the study. The acetylcholine receptor antibodies decreased significantly from a mean of 33.5 nmol/L at base line to 7.8 nmol/L at the final visit. In the thymectomy group with combined prednisone and tacrolimus stratified by histology of the thymus, the mean probability to attain complete stable remission at 5 years was 80.8% in patients with hyperplasia, 48.1% in thymic involution, and 9.3% in patients with thymoma. In 4.9% of patients, tacrolimus was withdrawn because of major adverse effects. Our results suggest that a low dose of tacrolimus is effective for MG and could be included to the armamentarium for this autoimmune disease. The present results should be interpreted considering the limitations of a retrospective clinical study. Confirmation of these results in randomized studies is desirable. PMID:18096852

  4. 317 Myasthenia Gravis and Asthma, Relationship between Two Different Disorders of the Immune System

    PubMed Central

    Velasco-Medina, Andrea Aida; Barreto-Sosa, Adriana; Gonzalez-Carsolio, Aida; Burbano-Ceron, Andres-Leonardo; Velázquez-Sámano, Guillermo

    2012-01-01

    Background Myasthenia gravis is an autoimmune disease caused by absence of neuromuscular transmission due to antibodies directed against the nicotinic AChR located at the neuromuscular junction. The main symptoms include muscle weakness in the affected muscles, which is worse after its use. Diagnosis is made upon clinical manifestations and finding of IgG. Only 80 to 90% of patients with generalized disease are positive to these antibodies, and 30 to 50% with ophthalmologic manifestations. Other immunological alteration found in these patients is an overexpression of the low affinity IgE receptor (CD23). Asthma is characterized by shortness of breath, cough, wheezing and chest tightness caused by inflammation and a reversible contraction of bronchial smooth muscle. Immunologically is associated with a Th2 cytokine profile, mainly Il-4, Il-5, Il-13 and an increased IgE. Methods Allergic and autoimmune diseases represent an altered response of the immune system. Here we discuss the case of a patient who presented with an allergic disease at first then years later developed an autoimmune disease. Results Our patient had been diagnosed with persistent allergic rhinitis and asthma since 1992. He had been treated with inhaled corticosteroids, bronchodilators, intranasal corticosteroids, antihistamines and specific immunotherapy with control of symptoms. In June 2010 he noticed diplopia, palpebral ptosis and muscle weakness in upper extremities diagnosed with Myastenia gravis and started treatment with piridostigmine with adequate control of muscular symptoms. No thymoma was identified. Conclusions It has been noted the possible relationship between allergic and autoimmune diseases since in both there is an alteration in the regulatory mechanisms of the immune system. In this patient, we found the association between asthma and 19 years later the development of myasthenia gravis. Some of the explanations for this kind of association is the expression of CD23 in myasthenia

  5. The role of muscle-specific tyrosine kinase (MuSK) and mystery of MuSK myasthenia gravis

    PubMed Central

    Koneczny, Inga; Cossins, Judith; Vincent, Angela

    2014-01-01

    MuSK myasthenia gravis is a rare, severe autoimmune disease of the neuromuscular junction, only identified in 2001, with unclear pathogenic mechanisms. In this review we describe the clinical aspects that distinguish MuSK MG from AChR MG, review what is known about the role of MuSK in the development and function of the neuromuscular junction, and discuss the data that address how the antibodies to MuSK lead to neuromuscular transmission failure. PMID:23458718

  6. Novel Complement Inhibitor Limits Severity of Experimentally Myasthenia Gravis

    PubMed Central

    Soltys, Jindrich; Kusner, Linda L.; Young, Andrew; Richmonds, Chelliah; Hatala, Denise; Gong, Bendi; Shanmugavel, Vaithesh; Kaminski, Henry J.

    2011-01-01

    Objective Complement mediated injury of the neuromuscular junction is considered a primary disease mechanism in human myasthenia gravis and animal models of experimentally acquired myasthenia gravis (EAMG). We utilized active and passive models of EAMG to investigate the efficacy of a novel C5 complement inhibitor rEV576, recombinantly produced protein derived from tick saliva, in moderating disease severity. Methods Standardized disease severity assessment, serum complement hemolytic activity, serum cytotoxicity, acetylcholine receptor (AChR) antibody concentration, IgG subclassification, and C9 deposition at the neuromuscular junction were used to assess the effect of complement inhibition on EAMG induced by administration of AChR antibody or immunization with purified AChR. Results Administration of rEV576 in passive transfer EAMG limited disease severity as evidenced by 100% survival rate and a low disease severity score. In active EAMG, rats with severe and mild EAMG were protected from worsening of disease and had limited weight loss. Serum complement activity (CH50) in severe and mild EAMG was reduced to undetectable levels during treatment, and C9 deposition at the neuromuscular junction was reduced. Treatment with rEV576 resulted in reduction of toxicity of serum from severe and mild EAMG rats. Levels of total AChR IgG, and IgG2a antibodies were similar, but unexpectedly, the concentration of complement fixing IgG1 antibodies was lower in a group of rEV576-treated animals, suggesting an effect of rEV576 on cellular immunity. Interpretation Inhibition of complement significantly reduced weakness in two models of EAMG. C5 inhibition could prove to be of significant therapeutic value in human myasthenia gravis. PMID:19194881

  7. Myasthenia gravis and thymic neoplasms: A brief review

    PubMed Central

    Kumar, Ritesh

    2015-01-01

    Thymoma is the most common mediastinal tumor. They have varied presentation ranging from asymptomatic incidental mediastinal masses to locally extensive tumor with compressive symptoms and distant metastases. They have frequent association with various paraneoplastic syndromes (PNS). The most common PNS associated with thymoma is myasthenia gravis (MG). Patients of thymoma with MG have a favourable outcome due to early disclosure of the disease. Histologically they are classified into five subtypes and Masaoka-Koga staging system is used for staging. Surgery, chemotherapy and radiotherapy play an important role along with anti-myasthenia drugs. This review would like to highlight the association of thymoma with MG and associated clinical and therapeutic issues. PMID:26677446

  8. The value of computed tomography in myasthenia gravis

    SciTech Connect

    Brown, L.R.; Muhm, J.R.; Sheedy, P.F. II; Unni, K.K.; Bernatz, P.E.; Hermann, R.C. Jr.

    1983-01-01

    In a 5 year study, 19 patients with myasthenia gravis were studied by computed tomography (CT) and underwent thymectomy. CT was accurate in detecting the nine true thymic masses but could not differentiate thymomas from nonthymomatous masses, including thymic cysts. No thymoma was found in a patient under 25 years of age. In one case, the 18 sec scanner could not differentiate a large gland from a thymoma. In eight cases, glands with histologic thymic hyperplasia and histologically normal thymus appeared to be similar and could not be differentiated by CT.

  9. Myasthenia gravis: determinants for independent ventilation after transsternal thymectomy.

    PubMed

    Younger, D S; Braun, N M; Jaretzki, A; Penn, A S; Lovelace, R E

    1984-03-01

    We evaluated the respiratory function of 32 patients with myasthenia gravis who had transsternal thymectomy. Preoperative clinical, pulmonary function, and respiratory muscle pressure data were submitted to stepwise logistic regression analysis to identify preoperative factors that correlated with duration of supported ventilation after surgery. Ten patients (31%) had postoperative supported ventilation for more than 3 days. The duration of ventilatory support correlated most closely with maximal static expiratory pressure (r = 0.714, p less than 0.001). Expiratory weakness, by reducing cough efficacy, seems to be the main determinant that predicts need for longer postoperative supported ventilation. PMID:6538272

  10. Pathogenesis of myasthenia gravis: update on disease types, models, and mechanisms.

    PubMed

    Phillips, William D; Vincent, Angela

    2016-01-01

    Myasthenia gravis is an autoimmune disease of the neuromuscular junction (NMJ) caused by antibodies that attack components of the postsynaptic membrane, impair neuromuscular transmission, and lead to weakness and fatigue of skeletal muscle. This can be generalised or localised to certain muscle groups, and involvement of the bulbar and respiratory muscles can be life threatening. The pathogenesis of myasthenia gravis depends upon the target and isotype of the autoantibodies. Most cases are caused by immunoglobulin (Ig)G1 and IgG3 antibodies to the acetylcholine receptor (AChR). They produce complement-mediated damage and increase the rate of AChR turnover, both mechanisms causing loss of AChR from the postsynaptic membrane. The thymus gland is involved in many patients, and there are experimental and genetic approaches to understand the failure of immune tolerance to the AChR. In a proportion of those patients without AChR antibodies, antibodies to muscle-specific kinase (MuSK), or related proteins such as agrin and low-density lipoprotein receptor-related protein 4 (LRP4), are present. MuSK antibodies are predominantly IgG4 and cause disassembly of the neuromuscular junction by disrupting the physiological function of MuSK in synapse maintenance and adaptation. Here we discuss how knowledge of neuromuscular junction structure and function has fed into understanding the mechanisms of AChR and MuSK antibodies. Myasthenia gravis remains a paradigm for autoantibody-mediated conditions and these observations show how much there is still to learn about synaptic function and pathological mechanisms. PMID:27408701

  11. Pathogenesis of myasthenia gravis: update on disease types, models, and mechanisms

    PubMed Central

    Phillips, William D.; Vincent, Angela

    2016-01-01

    Myasthenia gravis is an autoimmune disease of the neuromuscular junction (NMJ) caused by antibodies that attack components of the postsynaptic membrane, impair neuromuscular transmission, and lead to weakness and fatigue of skeletal muscle. This can be generalised or localised to certain muscle groups, and involvement of the bulbar and respiratory muscles can be life threatening. The pathogenesis of myasthenia gravis depends upon the target and isotype of the autoantibodies. Most cases are caused by immunoglobulin (Ig)G1 and IgG3 antibodies to the acetylcholine receptor (AChR). They produce complement-mediated damage and increase the rate of AChR turnover, both mechanisms causing loss of AChR from the postsynaptic membrane. The thymus gland is involved in many patients, and there are experimental and genetic approaches to understand the failure of immune tolerance to the AChR. In a proportion of those patients without AChR antibodies, antibodies to muscle-specific kinase (MuSK), or related proteins such as agrin and low-density lipoprotein receptor-related protein 4 (LRP4), are present. MuSK antibodies are predominantly IgG4 and cause disassembly of the neuromuscular junction by disrupting the physiological function of MuSK in synapse maintenance and adaptation. Here we discuss how knowledge of neuromuscular junction structure and function has fed into understanding the mechanisms of AChR and MuSK antibodies. Myasthenia gravis remains a paradigm for autoantibody-mediated conditions and these observations show how much there is still to learn about synaptic function and pathological mechanisms. PMID:27408701

  12. Myasthenia gravis mimicking stroke: a case series with sudden onset dysarthria.

    PubMed

    Tremolizzo, Lucio; Giopato, Federico; Piatti, Maria Luisa; Rigamonti, Andrea; Ferrarese, Carlo; Appollonio, Ildebrando

    2015-06-01

    Myasthenia gravis (MG) is an immune-mediated disorder characterized by fluctuating fatigue of skeletal muscles, often involving extrinsic ocular or bulbar districts. Myasthenia gravis in the elderly is an under-recognized condition, sometimes confused with cerebrovascular disease. Here we present a case series of myasthenia patients which onset was characterized by sudden dysarthria, clearly raising this diagnostic dilemma. In the workout of sudden onset isolated dysarthria, MG should be always considered. In fact, even if myasthenia is a rare condition, lacunar stroke only with this clinical presentation is also unusual, and significant risks may arise (e.g., unexpected myasthenic crisis). PMID:25648108

  13. Myasthenia Gravis Development and Crisis Subsequent to Multiple Sclerosis

    PubMed Central

    Gharagozli, Kurosh; Shojaei, Maziar; Harandi, Ali Amini; Akbari, Nayyereh; Ilkhani, Manouchehr

    2011-01-01

    During the last decade, sporadic combination of multiple sclerosis (MS) and myasthenia gravis (MG) has been reported repeatedly. Although these are anecdotal, they are important enough to raise concerns about co-occurrence of MG and MS. Here, we present a case of an MS patient who developed an MG crisis. She had received interferon for relapsing remitting MS. Interestingly, she developed an MG crisis 4 years after the diagnosis of MS. MS and MG have relatively the same distribution for age, corresponding to the younger peak of the bimodal age distribution in MG. They also share some HLA typing characteristics. Furthermore, some evidences support the role of systemic immune dysregulation due to a genetic susceptibility that is common to these two diseases. The association may be underdiagnosed because of the possible overlap of symptoms especially bulbar manifestations in which either MG or MS can mimic each other, leading to underestimating incidence of the combination. The evidence warrants physicians, especially neurologists, to always consider the possibility of the other disease when encountering any patients either with MS or MG. Anecdotal and sporadic reports of combination of multiple sclerosis (MS) and myasthenia gravis (MG) have been raised concerns about co-occurrence of them. PMID:21629802

  14. International consensus guidance for management of myasthenia gravis

    PubMed Central

    Wolfe, Gil I.; Benatar, Michael; Evoli, Amelia; Gilhus, Nils E.; Illa, Isabel; Kuntz, Nancy; Massey, Janice M.; Melms, Arthur; Murai, Hiroyuki; Nicolle, Michael; Palace, Jacqueline; Richman, David P.; Verschuuren, Jan; Narayanaswami, Pushpa

    2016-01-01

    Objective: To develop formal consensus-based guidance for the management of myasthenia gravis (MG). Methods: In October 2013, the Myasthenia Gravis Foundation of America appointed a Task Force to develop treatment guidance for MG, and a panel of 15 international experts was convened. The RAND/UCLA appropriateness methodology was used to develop consensus guidance statements. Definitions were developed for goals of treatment, minimal manifestations, remission, ocular MG, impending crisis, crisis, and refractory MG. An in-person panel meeting then determined 7 treatment topics to be addressed. Initial guidance statements were developed from literature summaries. Three rounds of anonymous e-mail votes were used to attain consensus on guidance statements modified on the basis of panel input. Results: Guidance statements were developed for symptomatic and immunosuppressive treatments, IV immunoglobulin and plasma exchange, management of impending and manifest myasthenic crisis, thymectomy, juvenile MG, MG associated with antibodies to muscle-specific tyrosine kinase, and MG in pregnancy. Conclusion: This is an international formal consensus of MG experts intended to be a guide for clinicians caring for patients with MG worldwide. PMID:27358333

  15. Sleep disorders in patients with myasthenia gravis: a systematic review.

    PubMed

    Fernandes Oliveira, Ezequiel; Nacif, Sergio R; Alves Pereira, Nixon; Fonseca, Nina Teixeira; Urbano, Jéssica Julioti; Perez, Eduardo Araújo; Cavalcante, Valéria; Santos Oliveira, Claudia; Insalaco, Giuseppe; Oliveira, Acary Sousa Bulle; Oliveira, Luis Vicente Franco

    2015-06-01

    [Purpose] This systematic review evaluated the presence of sleep-disordered breathing in patients with myasthenia gravis and clarified the role of physiotherapy. [Subjects and Methods] We followed the PRISMA declaration criteria. The evaluation was performed in accordance with the STROBE statement for observational and cross-sectional studies and the CONSORT checklist for clinical trials. Searches were followed by hand on MEDLINE, EMBASE, SciELO, PubMed Central, and the Cochrane Central Register of Controlled Trials. [Results] Our searches yielded a total of 36 studies published between 1970 and 2014. The number of patients involved ranged from 9-490. Of the 36 studies, 19 articles were excluded because they did not meet the inclusion criteria. Therefore, 17 observational, cross-sectional, or clinical studies assessing the quality of sleep and prevalence of sleep disorders in patients with myasthenia gravis were eligible for our review. [Conclusion] Some studies of patients with MG show that patients with MG are associated with poor sleep quality, excessive daytime sleepiness, presence of restless syndrome, and a higher incidence of SDB, while other studies do not report such associations. Therefore, given the current inconclusive evidence and limited literature, further study of sleep disturbances in patients with MG is needed. PMID:26180370

  16. Sleep disorders in patients with myasthenia gravis: a systematic review

    PubMed Central

    Fernandes Oliveira, Ezequiel; Nacif, Sergio R.; Alves Pereira, Nixon; Fonseca, Nina Teixeira; Urbano, Jéssica Julioti; Perez, Eduardo Araújo; Cavalcante, Valéria; Santos Oliveira, Claudia; Insalaco, Giuseppe; Oliveira, Acary Sousa Bulle; Oliveira, Luis Vicente Franco

    2015-01-01

    [Purpose] This systematic review evaluated the presence of sleep-disordered breathing in patients with myasthenia gravis and clarified the role of physiotherapy. [Subjects and Methods] We followed the PRISMA declaration criteria. The evaluation was performed in accordance with the STROBE statement for observational and cross-sectional studies and the CONSORT checklist for clinical trials. Searches were followed by hand on MEDLINE, EMBASE, SciELO, PubMed Central, and the Cochrane Central Register of Controlled Trials. [Results] Our searches yielded a total of 36 studies published between 1970 and 2014. The number of patients involved ranged from 9–490. Of the 36 studies, 19 articles were excluded because they did not meet the inclusion criteria. Therefore, 17 observational, cross-sectional, or clinical studies assessing the quality of sleep and prevalence of sleep disorders in patients with myasthenia gravis were eligible for our review. [Conclusion] Some studies of patients with MG show that patients with MG are associated with poor sleep quality, excessive daytime sleepiness, presence of restless syndrome, and a higher incidence of SDB, while other studies do not report such associations. Therefore, given the current inconclusive evidence and limited literature, further study of sleep disturbances in patients with MG is needed. PMID:26180370

  17. Anti-MuSK myasthenia gravis with prolonged remission.

    PubMed

    Bouwyn, Jean Paul; Magnier, Patrick; Bédat-Millet, Anne-Laure; Ahtoy, Patrick; Maltête, David; Lefaucheur, Romain

    2016-07-01

    Myasthenia gravis (MG) with antibodies against muscle-specific tyrosine kinase (MuSK) is a rare disorder of neuromuscular transmission affecting preferentially bulbar, neck and respiratory muscles. We report the case of a 22-year-old man who presented with diplopia on lateral gaze to both sides, facial diplegia, nasal dysarthria and dysphagia. Repetitive nerve stimulation of the trapezius and orbicularis oculi muscles showed amplitude decrements of 19% and 41% respectively supporting the diagnosis of myasthenia gravis. MUsK antibodies were positive. Corticosteroids were introduced and then tapered and discontinued at 6 months after initiation. The patient remained in remission and asymptomatic for 4 years without ongoing treatment or prior treatment with rituximab after this first relapse of MuSK-MG. MuSK- MG is considered a hard-to-treat condition and patients generally remain dependent on immunosuppression or prior treatment with rituximab. Our observation highlights that patients with MuSK-MG can have a benign course and that continued immunosuppressive or immunomodulatory therapy may not always be required. PMID:27161384

  18. Thymectomy Cures Diabetes Mellitus and Ameliorates Myasthenia Gravis in a Patient with Thymus Hyperplasia and Hyperthyroidism: Report of a Case.

    PubMed

    Feng, Shiyun; Zhang, Yao; Cui, Youbin; Chen, Yu

    2015-12-01

    Myasthenia gravis (MG) is a devastating autoimmune disease that involves the acetylcholine receptor (AchR) in the postsynaptic membrane of the neuromuscular junction. It is not uncommon for MG to accompany with other autoimmune diseases and complicate with multiple organ dysfunction. Here, we report on an 18-year-old female patient with a rare case of MG concomitant with thymus hyperplasia, diabetes mellitus, and hyperthyroidism. After full excision of the hyperplastic thymus gland, the patient's muscle weakness was greatly improved and her blood glucose level was restored to normal at the 6-month follow-up. PMID:26884666

  19. Ocular myasthenia gravis. A critical review of clinical and pathophysiological aspects.

    PubMed

    Sommer, N; Melms, A; Weller, M; Dichgans, J

    1993-01-01

    Myasthenia gravis (MG) is probably the best studied autoimmune disease caused by autoantibodies against the acetylcholine receptor (AChR) at the neuromuscular junction, subsequently leading to abnormal fatigability and weakness of skeletal muscle. Extraocular muscle weakness with droopy eyelids and double vision is present in about 90% of MG patients, being the initial complaint in about 50%. In approximately 20% of the patients the disease will always be confined to the extraocular muscles. The single most important diagnostic test is the detection of serum antibodies against AChR which is positive in 90% of patients with generalized MG, but only in 65% with purely ocular MG. Electromyographic studies and the Tensilon test are of diagnostic value in clear-cut cases, but may be equivocal in purely ocular myasthenia, especially the latter not rarely producing false-positive results. Treatment response to corticosteroids and anti-cholinesterase agents is satisfactory in many patients with ocular MG, however other immunosuppressive drugs may also be needed. Pathogenetically relevant steps of the underlying autoimmune process have been elucidated during the last few years; nevertheless a number of questions remain open, especially what starts off the autoimmune process, and why are eye muscles so frequently involved in MG? PMID:8156854

  20. Anesthetic Management of a Patient with Myasthenia Gravis for Meningioma Surgery - A Case Report.

    PubMed

    Srivastava, V K; Agrawal, S; Ahmed, M; Sharma, S

    2015-01-01

    Myasthenia gravis is a disease of great challenge to the anesthesiologist, because it affects the neuromuscular junction. Anesthetic management involves either muscle relaxant or non-muscle relaxant techniques. This case report documents the safe use of fentanyl, propofol and sevoflurane combination guided by bispectral index, without the use of muscle relaxants in a patient with myasthenia gravis who presented for meningioma surgery. PMID:26620756

  1. Myasthenia gravis and amyotrophic lateral sclerosis: A pathogenic overlap.

    PubMed

    Gotaas, Håvard Torvik; Skeie, Geir Olve; Gilhus, Nils Erik

    2016-06-01

    The aim was to examine potential joint disease mechanisms for myasthenia gravis (MG) and amyotrophic lateral sclerosis (ALS) through the examination of long-term patient cohorts for comorbidity. Recent studies support early involvement of the neuromuscular junction in ALS patients with subsequent degeneration of motor neurons. Medical records at Haukeland University Hospital from 1987 to 2012 were examined for International Classification of Diseases diagnostic codes for MG and ALS. Sera were re-tested for antibodies to acetylcholine receptor, titin, MuSK and GM1. We report one patient with both MG and ALS, and another 3 patients with suggestive evidence of both conditions. This is far more than expected from prevalence and incidence figures in this area if the disorders were unrelated. Our data suggest that immunological mechanisms in the neuromuscular junction are relevant in ALS pathogenesis. Attention should be given to possible therapeutic targets in the neuromuscular junction and muscle in ALS patients. PMID:27102003

  2. Elderly-onset familial myasthenia gravis in two siblings.

    PubMed

    Hirunagi, Tomoki; Tsujikawa, Koyo; Hasegawa, Yasuhiro; Mano, Kazuo; Katsuno, Masahisa

    2016-06-01

    Myasthenia gravis (MG) occasionally occurs in a family, but elderly-onset (≥65 years) familial MG has been rarely reported. We here report the case of two siblings with elderly-onset MG (mean onset age: 72.5 years) and present the human leukocyte antigen (HLA) profiles (HLA-A, -B, -DR) of their family. Both patients developed generalized MG with elevated serum acetylcholine receptor antibody titers at their seventies. Of six siblings, the two patients and one unaffected sibling shared the same HLA haplotypes. Our study indicates that elderly-onset MG can occur in a family and that familial occurrence of MG may be related to certain HLA alleles. PMID:27132121

  3. The search for new antigenic targets in myasthenia gravis.

    PubMed

    Cossins, Judith; Belaya, Katsiaryna; Zoltowska, Katarzyna; Koneczny, Inga; Maxwell, Susan; Jacobson, Leslie; Leite, Maria Isabel; Waters, Patrick; Vincent, Angela; Beeson, David

    2012-12-01

    Around 80% of myasthenia gravis patients have antibodies against the acetylcholine receptor, and 0-60% of the remaining patients have antibodies against the muscle-specific tyrosine kinase, MuSK. Another recently identified antigen is low-density lipoprotein receptor-related protein 4 (Lrp4). To improve the existing assays and widen the search for new antigenic targets, we have employed cell-based assays in which candidate target proteins are expressed on the cell surface of transfected cells and probed with patient sera. These assays, combined with use of myotube cultures to explore the effects of the antibodies, enable us to begin to identify new antigenic targets and test antibody pathogenicity in vitro. PMID:23278587

  4. Unusual clinical behaviour of thymoma with recurrent myasthenia gravis.

    PubMed

    Keditsu, Keduovinuo K; Karimundackal, George; Jambhekar, Nirmala A; Pramesh, C S

    2012-06-01

    A 58-year old man with thymoma and myasthenia gravis (MG) had undergone thymectomy 8 years ago with histopathologically confirmed non-invasive WHO-type AB thymoma. After 5 years of complete remission, symptoms of MG resurfaced, and a recurrent anterior mediastinal mass was detected for which he received radiotherapy. He presented to us 3 years later with productive cough and exertional dyspnoea; the positron emission tomography-computed tomography scan revealed a metabolically active pulmonary nodule in the right lung as the only site of disease for which a right lower lobectomy was done. Microscopy established an intrapulmonary WHO-type B2 thymoma and the patient is currently asymptomatic on steroids, anticholinesterase and immunosuppressant therapy. We discuss the variable and unpredictable course of thymomas; the possibility of transformation into more aggressive types with each recurrence, association with recurrent MG post-thymectomy and presentation several years later with metastatic disease. PMID:22378319

  5. Extracorporeal Immunoglobulin Elimination for the Treatment of Severe Myasthenia Gravis

    PubMed Central

    Blaha, M.; Pit'ha, J.; Blaha, V.; Lanska, M.; Maly, J.; Filip, S.; Langrova, H.

    2010-01-01

    Myasthenia gravis (MG) is a neuromuscular disorder leading to fluctuating muscle weakness and fatigue. Rarely, long-term stabilization is not possible through the use of thymectomy or any known drug therapy. We present our experience with extracorporeal immunoglobulin (Ig) elimination by immunoadsorption (adsorbers with human Ig antibodies). Acetylcholine receptor antibodies (AChRAs) were measured during long-term monitoring (4.7 ± 2.9 years; range 1.1–8.0). A total of 474 samples (232 pairs) were analyzed, and a drop in AChRA levels was observed (P = .025). The clinical status of patients improved and stabilized. Roughly 6.8% of patients experienced clinically irrelevant side effects. The method of Ig elimination by extracorporeal immunoadsorption (IA) is a clinical application of the recent biotechnological advances. It offers an effective and safe therapy for severe MG even when the disease is resistant to standard therapy. PMID:20300435

  6. Autoantibody profile and clinical characteristics in a cohort of Chinese adult myasthenia gravis patients.

    PubMed

    Hong, Yu; Li, Hai-Feng; Skeie, Geir Olve; Romi, Fredrik; Hao, Hong-Jun; Zhang, Xu; Gao, Xiang; Owe, Jone Furlund; Gilhus, Nils Erik

    2016-09-15

    Myasthenia gravis (MG) is an autoimmune disorder with heterogeneity. Antibodies against acetylcholine receptor (AChR), muscle-specific kinase (MuSK), titin and ryanodine receptor (RyR) were examined in 437 adult Chinese MG patients. The AChR, MuSK, titin and RyR antibodies were found in 82.2%, 2.3%, 28.4% and 23.8% of all patients. Autoantibody profiles vary among different MG subgroups. Thymoma MG patients had high frequencies of AChR (99.2%), titin (50.8%) and RyR antibodies (46.9%). The titin and RyR antibodies also showed high frequencies in late onset patients (54.4% and 33.3%, respectively). These two antibodies may indicate an underlying thymoma when combined. The patients with titin and RyR antibodies tend to have more severe disease and worse outcome, and may need more active immunosuppressive treatment. PMID:27609275

  7. [Onset of myasthenia gravis in primary care. Presentation of a case].

    PubMed

    Álvarez-Cordovés, M M; Mirpuri-Mirpuri, P G; Pérez-Monje, A

    2013-10-01

    Myasthenia gravis is an autoimmune disorder of neuromuscular transmission involving the production of autoantibodies directed against skeletal muscle receptors, in most cases of acetylcholine. Clinically it is characterized by the appearance of muscle weakness after prolonged activity, which tends to recover after a period of rest, or administration of acetylcholinesterase inhibitors. It is a relatively rare disease, although the prevalence has increased by improved diagnosis and increased longevity of the population. The diagnosis can be based on evidence after it is suspected using pharmacological, immunological or electrophysiology tests. Treatment can be divided into: symptomatic, short term and long term. We report the case of a patient who complained of diplopia, this muscle weakness being the most common initial symptom of the disease. PMID:24095170

  8. Serum Metabolomic Response of Myasthenia Gravis Patients to Chronic Prednisone Treatment

    PubMed Central

    Sengupta, Manjistha; Cheema, Amrita; Kaminski, Henry J.; Kusner, Linda L.

    2014-01-01

    Prednisone is often used for the treatment of autoimmune and inflammatory diseases but they suffer from variable therapeutic responses and significant adverse effects. Serum biological markers that are modulated by chronic corticosteroid use have not been identified. Myasthenia gravis is an autoimmune neuromuscular disorder caused by antibodies directed against proteins present at the post-synaptic surface of neuromuscular junction resulting in weakness. The patients with myasthenia gravis are primarily treated with prednisone. We analyzed the metabolomic profile of serum collected from patients prior to and after 12 weeks of prednisone treatment during a clinical trial. Our aim was to identify metabolites that may be treatment responsive and be evaluated in future studies as potential biomarkers of efficacy or adverse effects. Ultra-performance liquid chromatography coupled with electro-spray quadrupole time of flight mass spectrometry was used to obtain comparative metabolomic and lipidomic profile. Untargeted metabolic profiling of serum showed a clear distinction between pre- and post- treatment groups. Chronic prednisone treatment caused upregulation of membrane associated glycerophospholipids: phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, 1, 2-diacyl-sn glycerol 3 phosphate and 1-Acyl-sn-glycero-3-phosphocholine. Arachidonic acid (AA) and AA derived pro-inflammatory eicosanoids such as 18-carboxy dinor leukotriene B4 and 15 hydroxyeicosatetraenoic acids were reduced. Perturbations in amino acid, carbohydrate, vitamin and lipid metabolism were observed. Chronic prednisone treatment caused increase in membrane associated glycerophospholipids, which may be associated with certain adverse effects. Decrease of AA and AA derived pro-inflammatory eicosanoids demonstrate that immunosuppression by corticosteroid is via suppression of pro-inflammatory pathways. The study identified metabolomic fingerprints that can now be validated as prednisone

  9. Clinical characteristics and therapeutic evaluation of childhood myasthenia gravis

    PubMed Central

    YANG, ZHI-XIAO; XU, KAI-LI; XIONG, HUI

    2015-01-01

    This study aimed to analyze the clinical characteristics, classification and treatment of childhood myasthenia gravis (MG) and address the prognosis through follow-up. The clinical data of 135 children with MG were grouped according to clinical type and therapeutic drugs, retrospectively analyzed and prospectively monitored. Of the 135 MG patients, 85.2% had type I (ocular type), with only 4.2% progressing to systemic MG; 13.4% had type II (general type); and 1.5% had type III (fulminating type). Relapse occurred in 46.1% of the 102 patients that were followed up. The positive rate for the primary acetylcholine receptor antibody was 40.19%, without significant differences among clinical subtypes. The positive rate of the repetitive nerve stimulation frequency test by electromyography was 37.97%. Decreased expression of CD4+, CD8+, or CD3+ was present in 71% of the patients. Thymic hyperplasia was present in 5.93% of the patients, while 1.48% had thymoma. Steroid treatment was effective in the majority of the patients. Ocular type MG was common in this cohort of patients. The incidence and mortality of myasthenia crisis were low, the presence of concurrent thymoma was rare and only a limited number of children developed neurological sequelae. PMID:25780436

  10. Mechanism of nasal tolerance induced by a recombinant fragment of acetylcholine receptor for treatment of experimental myasthenia gravis.

    PubMed

    Im, S H; Barchan, D; Fuchs, S; Souroujon, M C

    2000-11-01

    Acetylcholine receptor (AChR) is the major autoantigen in myasthenia gravis (MG) and experimental autoimmune MG (EAMG). Here we analyze the mechanisms involved in suppression of ongoing EAMG in rats by nasal administration of a recombinant fragment from the human AChR alpha-subunit. We demonstrate that such a fragment, expressed without a fusion partner, confers nasal tolerance that can be adoptively transferred. Our observations suggest that the underlying mechanism of this nasal tolerance is active suppression involving a shift from a Th1 to a Th2/Th3-regulated AChR-specific response which may be mediated by down regulation of costimulatory factors. PMID:11063834

  11. Fusion protein of single-chain variable domain fragments for treatment of myasthenia gravis

    PubMed Central

    Li, Fangfang; Meng, Fanping; Jin, Quanxin; Sun, Changyuan; Li, Yingxin; Li, Honghua; Jin, Songzhu

    2014-01-01

    Single-chain variable domain fragment (scFv) 637 is an antigen-specific scFv of myasthenia gravis. In this study, scFv and human serum albumin genes were conjugated and the fusion protein was expressed in Pichia pastoris. The affinity of scFv-human serum albumin fusion protein to bind to acetylcholine receptor at the neuromuscular junction of human intercostal muscles was detected by immunofluorescence staining. The ability of the fusion protein to block myasthenia gravis patient sera binding to acetylcholine receptors and its stability in healthy serum were measured by competitive ELISA. The results showed that the inhibition rate was 2.0-77.4%, and the stability of fusion protein in static healthy sera was about 3 days. This approach suggests the scFv-human serum albumin is a potential candidate for specific immunosuppressive therapy of myasthenia gravis. PMID:25206900

  12. Seropositivity for West Nile Virus Antibodies in Patients Affected by Myasthenia Gravis

    PubMed Central

    Greco, Marilena; Cofano, Pietro; Lobreglio, Giambattista

    2016-01-01

    Background Myasthenia gravis (MG) is an autoimmune neuromuscular disease characterized by varying degrees of weakness of the skeletal muscles. Specific auto-antibodies against acetylcholine receptor (AChR) are present in the majority of MG patients, although the main cause behind its development still remains unclear. Recently MG development following West Nile virus (WNV) infection has been described in patients without any earlier evidence of MG. It is known that infectious agents trigger immune response and occasionally initiate autoimmune disease. WNV, the causative agent of both benign illness and neuroinvasive disease, has become endemic in many countries in all continents. Methods In the present study, 29 patients (15 males and 14 females, 19 - 78 years old) with confirmed diagnosis of MG and elevated levels of AChR autoantibodies were screened for the presence of serum anti-WNV antibodies and compared to a similar population affected by different autoimmune diseases. Indirect immunofluorescent antibody technique was used to evaluate the reaction of patients’ sera on cells infected by WNV. Results Positive fluorescent signals for anti-WNV IgG were obtained in 17% of MG patients, although no clinical manifestations related to WNV infection were reported. These results are in agreement with previous data and appear of great interest in the understanding of the pathogenic autoimmune mechanisms at the bases of MG development. Conclusion As already observed in other human autoimmune diseases, pathogen-triggered autoimmunity could be involved in MG by breaking immunological self-tolerance through possible mechanisms of molecular mimicry between virus proteins and AChR subunits. In predisposed individuals, WNV infection could also represent an additional risk factor to initiate MG. PMID:26858791

  13. Changes in inflammatory cytokine networks in myasthenia gravis.

    PubMed

    Uzawa, Akiyuki; Kanai, Tetsuya; Kawaguchi, Naoki; Oda, Fumiko; Himuro, Keiichi; Kuwabara, Satoshi

    2016-01-01

    Myasthenia gravis (MG) is an autoimmunological inflammatory disorder of the neuromuscular junction. Inflammation could be a key player for understanding the pathogenesis of MG. We measured the serum levels of 24 inflammatory cytokines in 43 patients with anti-acetylcholine receptor antibody-positive MG and 25 healthy controls. In patients with MG, serum levels of a proliferation-inducing ligand (APRIL), IL-19, IL-20, IL-28A and IL-35 were significantly increased as compared with controls (p < 0.05). Among them, IL-20, IL-28A and IL-35 were significantly decreased after treatment (p < 0.05). In clinical subtype analyses, APRIL and IL-20 were increased in patients with late-onset MG and IL-28A levels were increased in patients with thymoma-associated MG compared with healthy controls (p < 0.01). The results of the present study demonstrate both anti-inflammatory and inflammatory cytokines are upregulated in MG, reflecting the importance of cytokine-mediated inflammation and its regulation in MG pathophysiology. PMID:27172995

  14. Subcostal thoracoscopic extended thymectomy for patients with myasthenia gravis

    PubMed Central

    Tang, Yong; Ou, Zhu-An; Liao, Ming; Xuan, Yiwen; Su, Kai; Xu, En-Wu; Xiao, Haiping; Peng, Xiufan; Zhang, Zhuohua; Liu, Yan

    2016-01-01

    Background Extended thymectomy is indicated for patients with myasthenia gravis (MG) when drug-resistance or dependence is seen. We have employed a technique for subcostal thoracoscopic extended thymectomy (STET) on patients with MG. Methods Clinical data of 15 eligible patients who underwent STET in our department from February 2015 to November 2015 by the same surgical team were retrospectively analyzed. The operation time, blood loss, duration of postoperative hospital stay, thoracic drainage periods were concerned. Results All the surgeries were finished successfully without conversion to sternotomy. Mean operation time was 157.53±40.31 min (range, 73–275 min). Mean blood loss was 56.33±7.07 mL (range, 10–200 mL). Mean pleural drainage volume in the first 24 hours was 72.67±17.68 mL (range, 0–250 mL). Mean postoperative thoracic drainage periods were 1.20±0.71 days (range, 0–3 days). Mean duration of postoperative hospital stay was 6.13±0.71 days (range, 3–22 days). Conclusions This procedure showed satisfactory results for patients with MG. Moreover, the STET approach is more easily for surgeons to fully reveal the bilateral phrenic nerve and the upper thymic poles. We believe that STET is a satisfactory procedure for performing extended thymectomy in well selected patients. PMID:27076946

  15. Complications of radiologic contrast in patients with myasthenia gravis.

    PubMed

    Mehrizi, Mehyar; Pascuzzi, Robert M

    2014-09-01

    Use of older contrast agents during radiologic imaging in patients with myasthenia gravis (MG) has been associated with increased myasthenic symptoms and adverse drug reactions (ADRs). The effects of newer contrast agents have not been determined. A retrospective review of imaging safety in MG was conducted. Three hundred fifty-four imaging studies were analyzed. Procedures included 189 computed tomography (CT) images with and 106 without intravenous (IV) contrast and 42 magnetic resonance images (MRIs) with and 17 without contrast. In 108 patients for whom there was formal documentation of presence or absence of an immediate adverse response, only 1 who received CT IV contrast had an ADR (rate 0.93%). No ADRs or weakness were reported in patients who received MRI IV contrast. Our data suggest there is no significant immediate increased risk of myasthenic weakness with the use of modern radiologic contrast agents. The rate of ADRs in MG patients who receive CT IV contrast is now very low (0.93%). PMID:24677227

  16. HLA antigens in Japanese patients with myasthenia gravis.

    PubMed Central

    Matsuki, K; Juji, T; Tokunaga, K; Takamizawa, M; Maeda, H; Soda, M; Nomura, Y; Segawa, M

    1990-01-01

    HLA antigens in 104 Japanese patients and 41 families with myasthenia gravis (MG) were investigated. The frequencies of DR9 and DRw13 were significantly increased in the patients who developed MG before 3 yr of age. The DQw3 antigen was positive for all the patients that developed MG before 15 yr with only one exception. All the examined cases that developed MG before 3 yr (including this DQw3 negative patient) had the same DQA and DQB DNA restriction fragments. These HLA frequencies decreased as the age of onset increased, and no significant association was observed in adult-onset MG. No patients had B8, DR3, and DQw2. The relative risk was higher for the DR9/DRw13 heterozygotes (37.4) than for DR9 (16.4) or DRw13 (7.1) in the childhood-onset MG. Statistical analysis suggested that DR9 and DRw13 (or DQw1 and DQw3) act synergistically in the disease development. Family study revealed diverse DR9 haplotypes. The most frequent DRw13 haplotype was Bw44-BFF-C4A3B1-DRw13-DQw1, which may be evolutionarily related to the caucasian B8-DR3-DQw2 haplotype. These results showed that MG in early childhood in Japanese individuals is genetically different from that in adulthood and that in caucasians. Images PMID:1974553

  17. Changes in inflammatory cytokine networks in myasthenia gravis

    PubMed Central

    Uzawa, Akiyuki; Kanai, Tetsuya; Kawaguchi, Naoki; Oda, Fumiko; Himuro, Keiichi; Kuwabara, Satoshi

    2016-01-01

    Myasthenia gravis (MG) is an autoimmunological inflammatory disorder of the neuromuscular junction. Inflammation could be a key player for understanding the pathogenesis of MG. We measured the serum levels of 24 inflammatory cytokines in 43 patients with anti-acetylcholine receptor antibody-positive MG and 25 healthy controls. In patients with MG, serum levels of a proliferation-inducing ligand (APRIL), IL-19, IL-20, IL-28A and IL-35 were significantly increased as compared with controls (p < 0.05). Among them, IL-20, IL-28A and IL-35 were significantly decreased after treatment (p < 0.05). In clinical subtype analyses, APRIL and IL-20 were increased in patients with late-onset MG and IL-28A levels were increased in patients with thymoma-associated MG compared with healthy controls (p < 0.01). The results of the present study demonstrate both anti-inflammatory and inflammatory cytokines are upregulated in MG, reflecting the importance of cytokine-mediated inflammation and its regulation in MG pathophysiology. PMID:27172995

  18. Diagnosis of Tensilon-Negative Ocular Myasthenia Gravis By Daily Selfie.

    PubMed

    Guterman, Elan L; Botelho, James V; Horton, Jonathan C

    2016-09-01

    The initial symptoms of myasthenia gravis are usually ptosis and diplopia. The diagnosis is often confirmed by testing for anti-acetylcholine receptor antibodies or by observing the effects of intravenous edrophonium (Tensilon) injection. However, these standard tests may be negative in patients with isolated ocular findings. We present the case of an 83-year-old woman with negative serologic and Tensilon testing. She was asked to photograph herself daily. The resulting sequence of daily selfies captured striking fluctuations in her ocular alignment and ptosis. Daily selfies may be a useful strategy for confirming the clinical diagnosis of ocular myasthenia gravis. PMID:27529328

  19. Novel CXCL13 transgenic mouse: inflammation drives pathogenic effect of CXCL13 in experimental myasthenia gravis

    PubMed Central

    Weiss, Julia Miriam; Robinet, Marieke; Aricha, Revital; Cufi, Perrine; Villeret, Bérengère; Lantner, Frida; Shachar, Idit; Fuchs, Sara; Souroujon, Miriam C.

    2016-01-01

    Abnormal overexpression of CXCL13 is observed in many inflamed tissues and in particular in autoimmune diseases. Myasthenia gravis (MG) is a neuromuscular disease mainly mediated by anti-acetylcholine receptor autoantibodies. Thymic hyperplasia characterized by ectopic germinal centers (GCs) is a common feature in MG and is correlated with high levels of anti-AChR antibodies. We previously showed that the B-cell chemoattractant, CXCL13 is overexpressed by thymic epithelial cells in MG patients. We hypothesized that abnormal CXCL13 expression by the thymic epithelium triggered B-cell recruitment in MG. We therefore created a novel transgenic (Tg) mouse with a keratin 5 driven CXCL13 expression. The thymus of Tg mice overexpressed CXCL13 but did not trigger B-cell recruitment. However, in inflammatory conditions, induced by Poly(I:C), B cells strongly migrated to the thymus. Tg mice were also more susceptible to experimental autoimmune MG (EAMG) with stronger clinical signs, higher titers of anti-AChR antibodies, increased thymic B cells, and the development of germinal center-like structures. Consequently, this mouse model finally mimics the thymic pathology observed in human MG. Our data also demonstrated that inflammation is mandatory to reveal CXCL13 ability to recruit B cells and to induce tertiary lymphoid organ development. PMID:26771137

  20. Thymus involvement in myasthenia gravis: Epidemiological and clinical impacts of different self-tolerance breakdown mechanisms.

    PubMed

    Karni, Arnon; Asmail, Ali; Drory, Vivian E; Kolb, Hadar; Kesler, Anat

    2016-09-15

    The reasons for the abrogation of self-immunological tolerance in patients with myasthenia gravis (MG) may be different between those with concomitant thymic hyperplasia or thymoma, and those with no evidence of thymic involvement. We conducted a retrospective observational case series study to investigate the epidemiology as well as the clinical, serologic, and electromyographic (EMG) characteristics of individuals diagnosed as having MG. We found that the average age at MG onset of patients with either thymic hyperplasia or thymoma was much younger (by ~20years) than that of MG patients without thymic involvement. Thymic hyperplasia was more common in females than males. There were no differences in the rates of ocular MG vs. generalized MG among those three study groups. There were also no group differences in the rates of neuromuscular junction disfunction, as observed on EMG or by the results of serology tests for acetyl choline receptor antibody. Interestingly, only patients without thymic involvement had other autoimmune diseases, and most of them were females. The patients with other coexisting autoimmune disease had a similar age at MG onset as the other patients with no thymic involvement. These results shed light on the impact of epidemiological and clinical factors that result from different mechanisms of self-immunological tolerance breakdown that occurs in MG. PMID:27609276

  1. Systemic Lupus Erythematosus and Secondary Antiphospholipid Syndrome after Thymectomy for Myasthenia Gravis - A Case Report

    PubMed Central

    Miskovic, Rada; Plavsic, Aleksandra; Peric-Popadic, Aleksandra; Raskovic, Sanvila; Bogic, Mirjana

    2015-01-01

    INTRODUCTION: Systemic lupus erythematosus (SLE) and myasthenia gravis (MG) are autoimmune diseases that show some similarities: a higher incidence in young women, relapsing-remitting course and positive anti-nuclear antibodies (ANA). However, they are two different clinical syndromes, which can coexist or precede each other. Thymectomy is a therapeutic option for patients with severe MG or thymoma. There are many cases of SLE after thymectomy described in the literature, so the question arises whether thymectomy predisposes patients to SLE and what are imunopathogenetic mechanisms behind this process. CASE REPORT: We report a case of a patient who was diagnosed with SLE and secondary antiphospholipid syndrome (APS) 28 years after thymectomy for MG. Clinical picture of SLE was characterized by cutaneous and articular manifestations, polyserositis, lupus nephritis and immunological parameters showed positive ANA, anti-ds-DNA, excessive consumption of complement components, positive cryoglobulins. Clinical and laboratory immunological parameters for the diagnosis of secondary APS where also present. The patient was initially treated with glucocorticoids followed by mycophenolate mofetil. During one year follow-up patient was in a stable remission of SLE. CONCLUSION: Thymectomy for MG may predispose SLE development in some patients. Further studies are needed to better understand the connection between these two autoimmune diseases.

  2. Unmasking of myasthenia gravis during pegylated Alfa 2 a interferon and ribavirin therapy for chronic hepatitis C.

    PubMed

    Saleem, Ayesha

    2016-05-01

    Over last few decades, hepatitis C has emerged as a serious infection that has threatened the health and budgets of millions in the world. The objective of health professionals to treat it with recommended therapy of Alfa interferon and Ribavirin combination presents certain risks. One of the alarms is the ability of interferon to stimulate the production of autoantibodies in the body resulting in expression of autoimmune diseases in few who develop these antibodies. The case presented here is about unmasking of myasthenia gravis in a patient who received alfa interferon therapy for her chronic hepatitis C. Alfa interferon probably plays an important role in manifestation of the diseases in susceptible patients and all autoimmune diseases cannot be taken as mere side effects of the therapy. Clinicians need to be alert to pick up these diseases earlier so that the prompt management is possible. PMID:27183950

  3. Algaemia due to Prototheca wickerhamii in a patient with myasthenia gravis.

    PubMed Central

    Mohabeer, A J; Kaplan, P J; Southern, P M; Gander, R M

    1997-01-01

    Prototheca wickerhamii is a rare cause of systemic infection in humans. While some cases occur in previously healthy individuals, others are associated with a variety of preexisting diseases. Here we present, for the first time, a case of P. wickerhamii algaemia in a patient with myasthenia gravis. The patient was successfully treated with amphotericin B. PMID:9399541

  4. Disability and Functional Profiles of Patients with Myasthenia Gravis Measured with ICF Classification

    ERIC Educational Resources Information Center

    Leonardi, Matilde; Raggi, Alberto; Antozzi, Carlo; Confalonieri, Paolo; Maggi, Lorenzo; Cornelio, Ferdinando; Mantegazza, Renato

    2009-01-01

    The objective of this study is to describe functional profiles of patients with myasthenia gravis (MG), and the relationships among symptoms, activities and environmental factors (EF), by using WHO's International Classification of Functioning Disability and Health (ICF). Patients were consecutively enrolled at the Besta Institute of Milan, Italy.…

  5. An unexpected difficult intubation in a patient with myasthenia gravis undergoing video-assisted transcervical thymectomy

    PubMed Central

    Grasso, Nadia; Celestre, Chiara; Borrata, Francesco; Migliore, Marcello

    2013-01-01

    Although there are different methods to evaluate predictive parameters of difficult intubation in apparently normal patients, sometimes this event is unpredictable.We herein report a clinical case of difficult intubation during anaesthesia for video-assisted thymectomy in non-thymomatous myasthenia gravis. PMID:23749836

  6. Single fibre electromyographic studies in myasthenia gravis with repetitive nerve stimulation.

    PubMed Central

    Schwartz, M S; Stålberg, E

    1975-01-01

    A method is described for repetitive stimulation studies in myasthenia gravis using submaximal stimulation and single muscle fibre recording techniques. It was found that there were no impulse blockings due to neuromuscular transmission factors in normal subjects with 2 Hz stimulation, although there was a decrease or increase in the number of potentials which was caused by axonal stimulation factors. In myasthenia gravis a pathological picture was obtained, consisting of impulse blockings and facilitation at this rate in all of the eight patients studied, even those with only the ocular form of myasthenia and without surface decrement in the ADM. This technique allows study of both the minimally involved motor endplates and those with pronounced neuromuscular disturbances. Images PMID:1159439

  7. Cathepsin V is involved in the degradation of invariant chain in human thymus and is overexpressed in myasthenia gravis

    PubMed Central

    Tolosa, Eva; Li, Weijie; Yasuda, Yoshiyuki; Wienhold, Wolfgang; Denzin, Lisa K.; Lautwein, Alfred; Driessen, Christoph; Schnorrer, Petra; Weber, Ekkehard; Stevanovic, Stefan; Kurek, Raffael; Melms, Arthur; Brömme, Dieter

    2003-01-01

    Stepwise degradation of the invariant chain (Ii) is required for the binding of antigenic peptides to MHC class II molecules. Cathepsin (Cat) L in the murine thymus and Cat S in peripheral APCs have both been implicated in the last step of Ii degradation that gives rise to the class II–associated invariant chain peptides (CLIP). Cat V has been recently described as highly homologous to Cat L and exclusively expressed in human thymus and testis, but with no mouse orthologue. We report that Cat V is the dominant cysteine protease in cortical human thymic epithelial cells, while Cat L and Cat S seem to be restricted to dendritic and macrophage-like cells. Active Cat V in thymic lysosomal preparations was demonstrated by active-site labeling. Recombinant Cat V was capable of converting Ii into CLIP efficiently, suggesting that Cat V is the protease that controls the generation of αβ-CLIP complexes in the human thymus, in analogy to Cat L in mouse. Comparison of Cat V expression between thymi from patients with myasthenia gravis and healthy controls revealed a significantly higher expression level in the pathological samples, suggesting a potential involvement of this protease in the immunopathogenesis of myasthenia gravis, an autoimmune disease almost invariably associated with thymic pathology. PMID:12925692

  8. Azathioprine as a single immunosuppressive drug in the treatment of myasthenia gravis.

    PubMed

    Cosi, V; Lombardi, M; Erbetta, A; Piccolo, G

    1993-04-01

    We retrospectively evaluated results obtained from azathioprine (AZA) treatment on a selected sample of 40 patients affected by autoimmune myasthenia gravis (MG). Patients received AZA as a single immunosuppressive drug for at least 2 years. Twenty out of 40 patients received also a one-month course of cyclophosphamide (CP) before starting AZA. All patients started immunosuppressive treatment out of myasthenic crisis. After 3, 12 and 24 months of AZA treatment, 82.5%, 92.5% and 97.5% of the patients respectively showed improvement in functional state, disappearance of bulbar involvement, or both. The impressive percentage of short-term positive results did not seem influenced by pre-treatment by CP. Side effects included only minor and transitory gastrointestinal symptoms and reversible cytopenia. Although the patient population was either particularly suitable for AZA treatment or candidate to a better response, our data suggest that AZA might also have good short term effects in a subgroup of MG patients. PMID:8328322

  9. [Current status and future prospects of therapy for myasthenia gravis: considering thymectomy].

    PubMed

    Yoshikawa, Hiroaki; Iwasa, Kazuo; Takamori, Masaharu

    2011-07-01

    The benefits of thymectomy in non-thymomatous patients with myasthenia gravis (MG) remain controversial. The first detailed case of thymectomy in a patient with MG was reported in 1939, following which many cases were published. In 2000, Gronseth and Barohn reported the first meta-analysis of the effectiveness of thymectomy in MG patients without thymoma. They reviewed 28 papers systematically and reached these conclusions: (1) The benefit of thymectomy in non-thymomatous autoimmune MG has not been conclusively established, and (2) a well-designed controlled trial is essential. Following this report, Newsom-Davis et al. designed a thymectomy trial for non-thymomatous MG patients receiving prednisone (the MGTX study). Their study compared extended trans-sternal thymectomy (ETTX) combined with prednisone and prednisone alone groups with the aim to answer 3 questions: (1) Is the former more effective in improving myasthenic weakness? (2) Does the former require a lower total dose of prednisone, and thus decrease the likelihood of concurrent and long-term toxic effects? (3) Does the former enhance patients' quality of life by reducing adverse events and symptoms associated with the therapy? Currently, 67 centers, including our institute, are involved in this study. In total, 106 patients have been enrolled (the recruitment goal is 150). The patients are scheduled for a 5-year follow-up. The MGTX study will offer new information on the role of thymectomy in improving the quality of life of patients with MG. PMID:21747143

  10. Binding affinities of anti-acetylcholine receptor autoantibodies in myasthenia gravis

    SciTech Connect

    Bray, J.J.; Drachman, D.B.

    1982-01-01

    Antibodies directed against acetylcholine (ACh) receptors are present in the sera of nearly 90% of patients with myasthenia gravis (MG), and are involved in the pathogenesis of this autoimmune disease. However, the antibody titers measured by the standard radioimmunoassay correspond poorly with the clinical severity of the disease. To determine whether this disparity could be accounted for by differences in the binding affinities of anti-ACh receptor antibodies in different patients, we have measured the binding affinities of these autoantibodies in 15 sera from MG patients. The affinity constants (K/sub o/), as determined by Scatchard analysis, were all in the range of 10/sup 10/ M/sup -1/, comparable to the highest values reported in immunized animals. The affinity constants were truly representative of the population of autoantibodies detected by the radioimmunoassay, as shown by the remarkable linearity of the Scatchard plots (r/sup 2/>0.90) and the close correlation between the antibody titers determined by extrapolation of the Scatchard plots and by saturation analysis (r = 0.99; p < 0.001). There was only a 6-fold variation in affinity constants measured in this series of patients despite widely differing antibody titers and severity of the disease. Factors other than the titer and affinity of anti-ACh receptor antibodies may correlate better with the clinical manifestations of MG.

  11. Collagen Q--a potential target for autoantibodies in myasthenia gravis.

    PubMed

    Zoltowska Katarzyna, Marta; Belaya, Katsiaryna; Leite, Maria; Patrick, Waters; Vincent, Angela; Beeson, David

    2015-01-15

    Myasthenia gravis (MG) is an autoimmune disorder caused by autoantibodies targeting proteins expressed at the neuromuscular junction (NMJ). In most cases the targets are acetylcholine receptor (AChR), muscle-specific tyrosine kinase (MuSK), or occasionally low-density lipoprotein receptor-related protein 4 (LRP4), but there is still a group of patients, often called seronegative MG (SNMG), with unknown antibody targets. One potential target is collagen Q (COLQ), which is restricted to the NMJ and is crucial for anchoring the NMJ-specific form of acetylcholinesterase (AChE). 415 serum samples with a clinical diagnosis of MG and 43 control samples were screened for the presence of COLQ autoantibodies using a cell-based assay (CBA) with HEK293 cells overexpressing COLQ at the cell surface. COLQ antibodies were detected in 12/415 MG sera and in one/43 control samples. Five of the COLQ-Ab+individuals were also positive for AChR-Abs and 2 for MuSK-Abs. Although the COLQ antibodies were only present at low frequency, and did not differ significantly from the small control cohort, further studies could address whether they modify the clinical presentation or the benefits of anti-cholinesterase therapy. PMID:25577314

  12. Seropositive myasthenia and autoimmune autonomic ganglionopathy: cross reactivity or subclinical disease?

    PubMed

    Miglis, Mitchell G; Racela, Rikki; Kaufmann, Horacio

    2011-10-28

    Autoimmune autonomic ganglionopathy (AAG) and myasthenia gravis (MG) are both autoimmune channelopathies mediated by antibodies directed against nicotinic acetylcholine receptors. While both diseases target acetylcholine receptors, skeletal muscle and ganglionic receptor subtypes have key immunologic and genetic distinctions, and reports of patients with both AAG and MG are rare. We report a patient with antibody-confirmed AAG and elevated levels of ACh binding antibodies that did not meet clinical or electrodiagnostic criteria for MG. We presume that his skeletal muscle nAChR seropositivity was a false positive, perhaps due to the cross reactivity of the patient's ganglionic nAChR antibodies with skeletal nAChR subtypes. PMID:21745762

  13. Immunodominant regions for T helper-cell sensitization on the human nicotinic receptor alpha subunit in myasthenia gravis.

    PubMed Central

    Protti, M P; Manfredi, A A; Straub, C; Howard, J F; Conti-Tronconi, B M

    1990-01-01

    In myasthenia gravis an autoimmune response against the nicotinic acetylcholine receptor (AChR) occurs. The alpha subunit of the AChR contains both the epitope(s) that dominates the antibody response (main immunogenic region) and epitopes involved in T helper cell sensitization. In this study, overlapping synthetic peptides corresponding to the complete AChR alpha-subunit sequence were used to propagate polyclonal AChR-specific T helper cell lines from four myasthenic patients of different HLA types. Response of the T helper lines to the individual peptides was studied. Four immunodominant sequence segments were identified--i.e., residues 48-67, 101-120, 304-322, and 419-437. These regions did not include residues known to form the main immunogenic region or the cholinergic binding site, and they frequently contained sequence motifs that have been proposed to be related to T-epitope formation. Images PMID:2145582

  14. Myasthenia gravis as a 'stroke mimic'--it's all in the history.

    PubMed

    Shaik, Saiffuddin; Ul-Haq, Mian Ayaz; Emsley, Hedley C A

    2014-12-01

    An 85-year-old man presented to hospital as an emergency having difficulties with swallowing and speech. In the emergency department, he was assessed as having acute onset dysphagia and dysarthria in keeping with an acute stroke. Subsequently, it became apparent that although the symptoms were indeed of relatively acute onset, there was a clear description by the patient of fatigability and diurnal variation, prompting a working clinical diagnosis of myasthenia gravis. The patient followed a turbulent clinical course, and interpretation of investigation results proved not to be straightforward in the acute setting. Myasthenia gravis is an uncommon disorder but it is more common in the elderly. This case provides key learning points, particularly highlighting the value of prompt, accurate clinical assessment and the importance of adhering to the clinical diagnostic formulation. PMID:25468851

  15. Laparoscopic Sleeve Gastrectomy in a Morbidly Obese Patient with Myasthenia Gravis: A Review of the Management

    PubMed Central

    Ballal, Megana; Straker, Tracey

    2015-01-01

    Myasthenia gravis, a disorder of neuromuscular transmission, presents a unique challenge to the perioperative anesthetic management of morbidly obese patients. This report describes the case of a 27-year-old morbidly obese woman with a past medical history significant for myasthenia gravis and fatty liver disease undergoing bariatric surgery. Anesthesia was induced with intravenous agents and maintained with an inhalational and balanced intravenous technique. The nondepolarizing neuromuscular blocker Cisatracurium was chosen so that no reversal agents were given. Neostigmine was not used to antagonize the effects of Cisatracurium. The goal of this approach was to reduce the risk of complications such as postoperative mechanical ventilation. The anesthetic and surgical techniques used resulted in an uneventful hospital course. Therefore, we can minimize perioperative risks and complications by adjusting the anesthetic plan based on the patient's physiology and comorbidities as well as the pharmacology of the drugs. PMID:26294914

  16. New onset of myasthenia gravis 10 years after proton beam therapy for thymoma.

    PubMed

    Karasaki, Takahiro; Murakawa, Tomohiro; Nagayama, Kazuhiro; Nitadori, Jun-Ichi; Anraku, Masaki; Kikuchi, Yoshinao; Shinozaki-Ushiku, Aya; Igaki, Hiroshi; Nakajima, Jun

    2016-05-01

    A 36-year-old woman underwent proton beam therapy for encapsulated type B1 thymoma for curative intent at 66 GyE. Radiographically partial response was achieved. Although the tumor size had been stable since that time, she developed systemic myasthenia gravis 10 years after the proton therapy. Extended thymectomy was performed. There were no adhesions between the tumor and the pericardium, and there were no adhesions also between the tumor and the sternum, probably due to the favor of Bragg peak effect. Extensive hyalinization with small foci of viable tumor cells showing degenerated type A-like morphology was observed in the resected tumor. Whether the viable cells represented recurrence with degenerative changes or de novo tumor formation was unable to be determined, and whether the viable cells were responsible for the onset of myasthenia gravis remained unclear. PMID:25301055

  17. Memory in myasthenia gravis: neuropsychological tests of central cholinergic function before and after effective immunologic treatment.

    PubMed

    Glennerster, A; Palace, J; Warburton, D; Oxbury, S; Newsom-Davis, J

    1996-04-01

    There are reports of central cholinergic deficits in myasthenia gravis (MG) describing impaired performance on a variety of tests of memory with varying benefits from plasmapheresis. We tested 11 patients with symptomatic MG at the start of a trial of immunosuppressive treatment (prednisolone plus azathioprine or placebo) and again when in remission. The tests included the Logical Memory and Design Reproduction parts of the Wechsler Memory Scale, the Rey Auditory Verbal Learning Test, Peterson-Peterson task, and an auditory vigilance task. Muscle strength improved significantly over the period of treatment, but overall performance on tests of memory or attention did not. These results fail to substantiate reports of functionally significant and reversible central deficits in myasthenia gravis. PMID:8780106

  18. Association of HLA-Bw46DR9 combination with juvenile myasthenia gravis in Chinese.

    PubMed Central

    Chen, W H; Chiu, H C; Hseih, R P

    1993-01-01

    One hundred and fifty two Chinese patients with myasthenia gravis in Taiwan were investigated for HLA-A, B, C and DR/DQ typing. HLA-Bw46 and DR9 frequencies were significantly increased in patients compared with the control group, and there was a decrease in DR3. Further analysis between different subgroups of patients showed Bw46 and DR9 were more significantly increased in the juvenile group than in the adult group. No single HLA allele was associated with either clinical type or thymic pathology, but there was an excess of BW46DR9 combination in both juvenile and ocular type patients. The Chinese population with myasthenia gravis is characterised by earlier age at onset, more ocular forms and less clinically severe illness than in whites, and these characteristics indicate a special subgroup that correlates with the strong Bw46DR9 association. PMID:8482958

  19. [Merkel cell carcinoma of the skin in a patient with myasthenia gravis].

    PubMed

    Gianfreda, M; Caiffi, S; De Franceschi, T; Dodero, C; Durante, R; Faletti, P; Rebuttato, A; Schivo, A; Tassara, R

    2002-06-01

    Merkel cell carcinoma is a rare, aggressive neuroendocrine tumor of the skin commonly seen in the elderly on the head, neck and extremities, with a predisposition for local regional and distant spreading. A case of Merkel cell carcinoma occurred in a woman treated with immunosuppressive therapy for myasthenia gravis, is described and the possibility of a link between the immunosuppressive and/or oncogenic therapy and this tumor is suggested. PMID:12094153

  20. Colon Adenoma Implicating Myasthenia Gravis: A Case Report of a Patient with Postcolectomy Complications.

    PubMed

    Papachatzakis, Y; Tseliou, E; Tatouli, I; Dialoupi, I; Michas, F; Papadopoulou, E; Kousouris, D; Kontogiannis, S; Dimopoulos, M A

    2016-01-01

    We report the case of a 63-year-old patient with myasthenia gravis (MG) due to acetylcholine receptor antibodies (AChR) who underwent colectomy due to colon adenoma and developed myasthenic crisis and anastomosis leakage after surgery. The patient underwent two plasma exchanges, 4 and 6 days preoperatively, and received intravenous prednisolone and immunoglobulin infusion due to the crisis, which included primarily bulbar symptoms. The patient developed on the 10th postoperative day bowel obstruction symptoms and anastomosis leakage which required surgical repair and ileostomy. Bowel obstruction occurred in a patient with AChR related myasthenia after plasma exchange and during immunosuppression although it is more commonly reported in patients with thymoma related myasthenia. PMID:27610255

  1. Colon Adenoma Implicating Myasthenia Gravis: A Case Report of a Patient with Postcolectomy Complications

    PubMed Central

    Papachatzakis, Y.; Tatouli, I.; Dialoupi, I.; Michas, F.; Papadopoulou, E.; Kousouris, D.; Dimopoulos, M. A.

    2016-01-01

    We report the case of a 63-year-old patient with myasthenia gravis (MG) due to acetylcholine receptor antibodies (AChR) who underwent colectomy due to colon adenoma and developed myasthenic crisis and anastomosis leakage after surgery. The patient underwent two plasma exchanges, 4 and 6 days preoperatively, and received intravenous prednisolone and immunoglobulin infusion due to the crisis, which included primarily bulbar symptoms. The patient developed on the 10th postoperative day bowel obstruction symptoms and anastomosis leakage which required surgical repair and ileostomy. Bowel obstruction occurred in a patient with AChR related myasthenia after plasma exchange and during immunosuppression although it is more commonly reported in patients with thymoma related myasthenia. PMID:27610255

  2. Thymus cells in myasthenia gravis selectively enhance production of anti-acetylcholine-receptor antibody by autologous blood lymphocytes

    SciTech Connect

    Newsom-Davis, J.; Willcox, N.; Calder, L.

    1981-11-26

    We investigated the role of the thymus in 16 patients with myasthenia gravis without thymoma by studying the production of anti-acetylcholine-receptor antibody by thymic and blood lymphocytes cultured alone or together. In 10 responders (with the highest receptor-antibody titers in their plasma), cultured thymic cells spontaneously produced measurable receptor antibody. Receptor-antibody production by autologous blood lymphocytes was enhanced by the addition of responder's thymic cells, irradiated to abrogate antibody production and suppression (P<0.01). This enhancement was greater and more consistent than that by pokeweed mitogen; it depended on viable thymic cells, appeared to be selective for receptor antibody, and correlated with the ratio of thymic helper (OKT4-positive or OKT4+) to suppressor (OKT8+) T cells (P<0.01). These results suggest that myasthenic thymus contains cell-bound acetylcholine-receptor-like material or specific T cells (or both) that can aid receptor-antibody production. This may be relevant to the benefits of thymectomy in myasthenia and to the breakdown in self-tolerance in this and other autoimmune diseases.

  3. Myasthenia gravis: a long term follow‐up study of Swedish patients with specific reference to thymic histology

    PubMed Central

    Tsinzerling, Natalie; Lefvert, Ann‐Kari; Matell, Georg; Pirskanen‐Matell, Ritva

    2007-01-01

    Background Myasthenia gravis (MG) is an autoimmune disorder of neuromuscular transmission. The majority of patients show abnormal thymic histology. Setting The study was performed at the Myasthenia Gravis Centre, Karolinska University Hospital, and at the Immunological Research Laboratory, Centre for Molecular Medicine, Karolinska Institutet, Stockholm, Sweden. Patients and methods Information was collected retrospectively from 1956 and prospectively from 1975 on clinical data, concomitant diseases, concentration of serum acetylcholine receptor antibodies (AChR‐abs), immunosuppressive treatment (IS) and response to it, in 537 patients of whom 326 were thymectomised. Follow‐up time was 1.5–50 years. Results Age at onset of MG increased from a median age of 24 years before 1975 to a median age of 61 years after 2000. Thymoma was found in 65, hyperplasia (HPL) in 185 and a normal thymus in 76 patients. The trans‐sternal surgical approach for thymectomy was used in 255 patients (78%). In five patients with thymoma, MG appeared after thymectomy. Of 537 patients, 466 (87%) had circulating AChR‐abs. IS was given to 300 (56%) patients, mostly those with thymoma (85%). In total, 441 patients (82%) showed an improvement. One‐third of patients with HPL, a quarter of those with thymoma, one‐fifth of those with a normal thymus and one‐seventh of those not operated on went into remission. Conclusion The prognosis for the majority of patients with MG is favourable, irrespective of thymic histology. The cause may be the use of immunomodulating therapy. PMID:17353257

  4. Molecular mimicry and myasthenia gravis. An autoantigenic site of the acetylcholine receptor alpha-subunit that has biologic activity and reacts immunochemically with herpes simplex virus.

    PubMed Central

    Schwimmbeck, P L; Dyrberg, T; Drachman, D B; Oldstone, M B

    1989-01-01

    The large majority of patients with the autoimmune disease myasthenia gravis characteristically have detectable antibodies against the acetylcholine receptor (AChR). We used synthetic peptides to identify antibodies in sera of myasthenia gravis patients reactive with the human acetylcholine receptor (HuAChR) alpha-subunit, residues 160-167. Affinity purification of these antibodies, using the HuAChR alpha-subunit 157-170 peptide immobilized on thiopropyl-Sepharose, yielded IgG antibodies that bound to the native AChR and inhibited the binding of alpha-bungarotoxin to the receptor. The HuAChR alpha-subunit 160-167 peptide demonstrated specific immunological cross-reactivity with a shared homologous domain on herpes simplex virus glycoprotein D, residues 286-293, by both binding and inhibition studies. Thus, HuAChR alpha-subunit, residues 160-167, elicits antibodies in myasthenic patients that binds to the native AChR protein and is capable of eliciting a biologic effect. Immunologic cross-reactivity of this "self" epitope with herpes simplex virus suggest that this virus may be associated with the initiation of some cases of myasthenia. Images PMID:2551924

  5. Clinical features, pathogenesis, and treatment of myasthenia gravis: a supplement to the Guidelines of the German Neurological Society.

    PubMed

    Melzer, Nico; Ruck, Tobias; Fuhr, Peter; Gold, Ralf; Hohlfeld, Reinhard; Marx, Alexander; Melms, Arthur; Tackenberg, Björn; Schalke, Berthold; Schneider-Gold, Christiane; Zimprich, Fritz; Meuth, Sven G; Wiendl, Heinz

    2016-08-01

    Myasthenia gravis (MG) is an autoimmune antibody-mediated disorder of neuromuscular synaptic transmission. The clinical hallmark of MG consists of fluctuating fatigability and weakness affecting ocular, bulbar and (proximal) limb skeletal muscle groups. MG may either occur as an autoimmune disease with distinct immunogenetic characteristics or as a paraneoplastic syndrome associated with tumors of the thymus. Impairment of central thymic and peripheral self-tolerance mechanisms in both cases is thought to favor an autoimmune CD4(+) T cell-mediated B cell activation and synthesis of pathogenic high-affinity autoantibodies of either the IgG1 and 3 or IgG4 subclass. These autoantibodies bind to the nicotinic acetylcholine receptor (AchR) itself, or muscle-specific tyrosine-kinase (MuSK), lipoprotein receptor-related protein 4 (LRP4) and agrin involved in clustering of AchRs within the postsynaptic membrane and structural maintenance of the neuromuscular synapse. This results in disturbance of neuromuscular transmission and thus clinical manifestation of the disease. Emphasizing evidence from clinical trials, we provide an updated overview on immunopathogenesis, and derived current and future treatment strategies for MG divided into: (a) symptomatic treatments facilitating neuromuscular transmission, (b) antibody-depleting treatments, and PMID:26886206

  6. Oral administration of an immunodominant T-cell epitope downregulates Th1/Th2 cytokines and prevents experimental myasthenia gravis

    PubMed Central

    Baggi, Fulvio; Andreetta, Francesca; Caspani, Elisabetta; Milani, Monica; Longhi, Renato; Mantegazza, Renato; Cornelio, Ferdinando; Antozzi, Carlo

    1999-01-01

    The mucosal administration of the native antigen or peptide fragments corresponding to immunodominant regions is effective in preventing or treating several T cell–dependent models of autoimmune disease. No data are yet available on oral tolerance with immunodominant T-cell peptides in experimental autoimmune myasthenia gravis (EAMG), an animal model of B cell–dependent disease. We report that oral administration of the T-cell epitope α146-162 of the Torpedo californica acetylcholine receptor (TAChR) α-subunit suppressed T-cell responses to AChR and ameliorated the disease in C57Bl/6 (B6) mice. Protection from EAMG was associated with reduced serum Ab’s to mouse AChR and reduced AChR loss in muscle. The effect of Tα146-162 feeding was specific; treatment with a control peptide did not affect EAMG manifestations. The protective effect induced by peptide Tα146-162 was mediated by reduced production of IFN-γ, IL-2, and IL-10 by TAChR-reactive cells, suggesting T-cell anergy. TGF-β–secreting Th3 cells did not seem to be involved in tolerance induction. We therefore demonstrate that feeding a single immunodominant epitope can prevent an Ab-mediated experimental model of autoimmune disease. PMID:10545527

  7. Two simultaneous autoimmune processes in a patient presenting with respiratory insufficiency

    PubMed Central

    Troy, Lauren; Hamor, Paul; Bleasel, Jane; Corte, Tamera

    2014-01-01

    The idiopathic inflammatory myopathies, including dermatomyositis, are uncommon acquired autoimmune diseases, sometimes associated with interstitial lung disease. Myasthenia gravis, a separate autoimmune disorder involving the neuromuscular junction, has some overlapping clinical features but has only rarely been reported to occur simultaneously within the same patient. Here we present the first reported case of concomitant dermatomyositis, myasthenia gravis, and interstitial lung disease. PMID:25473554

  8. Progressive Outer Retinal Necrosis and Immunosuppressive Therapy in Myasthenia Gravis

    PubMed Central

    Coisy, Solène; Ebran, Jean-Marc; Milea, Dan

    2014-01-01

    Introduction Progressive outer retinal necrosis (PORN) is a rare but devastating infectious retinitis associated with varicella zoster virus (VZV) and responsible for severe visual loss. Case Report A 59-year-old man treated for generalized myasthenia with oral azathioprine and prednisone presented with severe unilateral necrotizing retinitis. Polymerase chain reaction of the aqueous and vitreous humors was diagnostic for VZV PORN. Conclusion VZV PORN is a severe potential ocular complication of immunosuppression, prompting urgent diagnosis and appropriate treatment. PMID:24926266

  9. Successful treatment of severe myasthenia gravis developed after allogeneic hematopoietic stem cell transplantation with plasma exchange and rituximab.

    PubMed

    Unal, Sule; Sag, Erdal; Kuskonmaz, Baris; Kesici, Selman; Bayrakci, Benan; Ayvaz, Deniz C; Tezcan, Ilhan; Yalnızoglu, Dilek; Uckan, Duygu

    2014-05-01

    Myasthenia gravis is among the rare complications after allogeneic hematopoietic stem cell transplantation and is usually associated with chronic GVHD. Herein, we report a 2-year and 10 months of age female with Griscelli syndrome, who developed severe myasthenia gravis at post-transplant +22nd month and required respiratory support with mechanical ventilation. She was unresponsive to cyclosporine A, methylprednisolone, intravenous immunoglobulin, and mycophenolate mofetil and the symptoms could only be controlled after plasma exchange and subsequent use of rituximab, in addition to cyclosporine A and mycophenolate mofetil maintenance. She is currently asymptomatic on the 6th month of follow-up. PMID:24307660

  10. Antigen-specific modulation of experimental myasthenia gravis: nasal tolerization with recombinant fragments of the human acetylcholine receptor alpha-subunit.

    PubMed

    Barchan, D; Souroujon, M C; Im, S H; Antozzi, C; Fuchs, S

    1999-07-01

    Myasthenia gravis (MG) and experimental autoimmune myasthenia gravis (EAMG) are antibody-mediated autoimmune diseases in which the nicotinic acetylcholine receptor (AcChoR) is the major autoantigen. The immune response in these diseases is heterogeneous and is directed to a wide variety of T and B cell epitopes of AcChoR. Candidate molecules for specific immunotherapy of MG should, therefore, have a broad specificity. We used recombinant fragments of the human AcChoR, encompassing the extracellular domain of the alpha-subunit, or shorter fragments derived from it, in experiments to modulate EAMG. We have demonstrated that intranasal administration of these recombinant fragments, which represent a major portion of epitopes involved in MG, prevents the induction of EAMG in rats and immunosuppresses an ongoing disease, as assessed by clinical symptoms, weight loss, and muscle AcChoR content. These effects on EAMG were accompanied by a marked reduction in the proliferative T-cell response and IL-2 production in response to AcChoR, in reduced anti-self AcChoR antibody titers and in an isotype switch of AcChoR-specific antibodies, from IgG2 to IgG1. We conclude that nasal tolerance induced by appropriate recombinant fragments of human AcChoR is effective in suppressing EAMG and might possibly be considered as a therapeutic modality for MG. PMID:10393952

  11. Antigen-specific modulation of experimental myasthenia gravis: Nasal tolerization with recombinant fragments of the human acetylcholine receptor α-subunit

    PubMed Central

    Barchan, Dora; Souroujon, Miriam C.; Im, Sin-Hyeog; Antozzi, Carlo; Fuchs, Sara

    1999-01-01

    Myasthenia gravis (MG) and experimental autoimmune myasthenia gravis (EAMG) are antibody-mediated autoimmune diseases in which the nicotinic acetylcholine receptor (AcChoR) is the major autoantigen. The immune response in these diseases is heterogeneous and is directed to a wide variety of T and B cell epitopes of AcChoR. Candidate molecules for specific immunotherapy of MG should, therefore, have a broad specificity. We used recombinant fragments of the human AcChoR, encompassing the extracellular domain of the α-subunit, or shorter fragments derived from it, in experiments to modulate EAMG. We have demonstrated that intranasal administration of these recombinant fragments, which represent a major portion of epitopes involved in MG, prevents the induction of EAMG in rats and immunosuppresses an ongoing disease, as assessed by clinical symptoms, weight loss, and muscle AcChoR content. These effects on EAMG were accompanied by a marked reduction in the proliferative T-cell response and IL-2 production in response to AcChoR, in reduced anti-self AcChoR antibody titers and in an isotype switch of AcChoR-specific antibodies, from IgG2 to IgG1. We conclude that nasal tolerance induced by appropriate recombinant fragments of human AcChoR is effective in suppressing EAMG and might possibly be considered as a therapeutic modality for MG. PMID:10393952

  12. Higher risk of myasthenia gravis in patients with thyroid and allergic diseases: a national population-based study.

    PubMed

    Yeh, Jiann-Horng; Kuo, Huang-Tsung; Chen, Hsuan-Ju; Chen, Yen-Kung; Chiu, Hou-Chang; Kao, Chia-Hung

    2015-05-01

    The aim of this study was to determine the risk of myasthenia gravis (MG) in patients with allergic or autoimmune thyroid disease in a large cohort representing 99% of the population in Taiwan. Data from the Taiwan National Health Insurance Database were used to conduct retrospective analyses. The study comprised 1689 adult patients with MG who were 4-fold frequency matched to those without MG by sex, age, and assigned the same index year. Multivariate logistic regression models were used to calculate the odds ratios and 95% confidence intervals for the association between allergic or autoimmune thyroid disease and MG. An increased subsequent risk of MG was observed in the patients with allergic conjunctivitis (AC), allergic rhinitis, Hashimoto thyroiditis, and Graves disease. The adjusted odds ratios (aORs) were 1.93 (1.71-2.18), 1.26 (1.09-1.45), 2.87 (1.18-6.97), and 3.97 (2.71-5.83), respectively. The aORs increased from 1.63 (1.43-1.85) in a patient with only 1 allergic or autoimmune thyroid disease to 2.09 (1.75-2.49) in a patient with 2 thyroid or allergic diseases to 2.82 (2.19-3.64) in a patient with ≥3 thyroid or allergic diseases. MG was associated with the cumulative effect of concurrent allergic and autoimmune thyroid disease with combined AC and Hashimoto thyroiditis representing the highest risk (aOR = 15.62 [2.88-87.71]). This population-based case-control study demonstrates the association between allergic or autoimmune thyroid disease and the risk of MG. The highest risk of subsequent MG was associated with combined AC and Hashimoto thyroiditis. PMID:26020387

  13. The Myotonic Plot Thickens: Electrical Myotonia in Antimuscle-Specific Kinase Myasthenia Gravis

    PubMed Central

    Magnussen, Marcus; Karakis, Ioannis; Harrison, Taylor B.

    2015-01-01

    Electrical myotonia is known to occur in a number of inherited and acquired disorders including myotonic dystrophies, channelopathies, and metabolic, toxic, and inflammatory myopathies. Yet, electrical myotonia in myasthenia gravis associated with antibodies against muscle-specific tyrosine kinase (MuSK) has not been previously reported. We describe two such patients, both of whom had a typical presentation of proximal muscle weakness with respiratory failure in the context of a significant electrodecrement in repetitive nerve stimulation. In both cases, concentric needle examination revealed electrical myotonia combined with myopathic motor unit morphology and early recruitment. These findings suggest that MuSK myasthenia should be included within the differential diagnosis of disorders with electrical myotonia. PMID:26770848

  14. Collagen Q is a key player for developing rational therapy for congenital myasthenia and for dissecting the mechanisms of anti-MuSK myasthenia gravis.

    PubMed

    Ohno, Kinji; Ito, Mikako; Kawakami, Yu; Ohtsuka, Kenji

    2014-07-01

    Acetylcholinesterase (AChE) at the neuromuscular junction (NMJ) is anchored to the synaptic basal lamina via a triple helical collagen Q (ColQ) in the form of asymmetric AChE (AChE/ColQ). We exploited the proprietary NMJ-targeting signals of ColQ to treat congenital myasthenia and to explore the mechanisms of autoimmune myasthenia gravis (MG). Mutations in COLQ cause congenital endplate AChE deficiency (CEAD). First, a single intravenous administration of adeno-associated virus serotype 8 (AAV8)-COLQ to Colq−/− mice normalized motor functions, synaptic transmission, and partly the NMJ ultrastructure. Additionally, injection of purified recombinant AChE/ColQ protein complex into gluteus maximus accumulated AChE in non-injected forelimbs. Second, MuSK antibody-positive MG accounts for 5-15 % of MG. In vitro overlay of AChE/ColQ to muscle sections of Colq−/− mice, as well as in vitro plate-binding of MuSK to ColQ, revealed thatMuSK-IgG blocks binding of ColQ to MuSK in a dose-dependent manner. Passive transfer of MuSK-IgG to wild-type mice markedly reduced the size and intensity of ColQ signals at NMJs. MuSK-IgG thus interferes with binding of ColQ to MuSK. Elucidation of molecular mechanisms of specific binding of ColQ to NMJ enabled us to ameliorate devastating myasthenic symptoms of Colq−/− mice and also to reveal underlying mechanisms of anti-MuSK-MG. PMID:24234034

  15. Cholinergic neuromuscular hyperactivity in patients with myasthenia gravis seropositive for MuSK antibody.

    PubMed

    Punga, Anna Rostedt; Flink, Roland; Askmark, Håkan; Stålberg, Erik V

    2006-07-01

    A 75-year-old man with severe oculobulbar myasthenia gravis (MG) treated with acetylcholine esterase inhibitors (AChEIs) was found to have muscle-specific tyrosine kinase (MuSK) antibodies. Neurophysiological examination displayed extra repetitive discharges after the compound motor action potential (CMAP) at low-frequency stimulation, possibly triggered by AChEI. This indicates an abnormal sensitivity to acetylcholine in patients with MuSK antibodies and may be a useful indicator of the adverse effect of AChEI treatment in these patients. PMID:16453324

  16. Stable Expression of Human Muscle-Specific Kinase in HEp-2 M4 Cells for Automatic Immunofluorescence Diagnostics of Myasthenia Gravis

    PubMed Central

    George, Sandra; Paulick, Silvia; Knütter, Ilka; Röber, Nadja; Hiemann, Rico; Roggenbuck, Dirk; Conrad, Karsten; Küpper, Jan-Heiner

    2014-01-01

    Muscle-specific kinase (MuSK) belongs to the nicotinic acetylcholine receptor complex which is targeted by pathogenic autoantibodies causing Myasthenia gravis. While up to 95% of patients with generalized Myasthenia gravis were shown to be positive for acetylcholine receptor-specific autoantibodies, up to 70% of the remaining patients develop autoantibodies against MuSK. Discrimination of the autoantibody specificity is important for therapy of Myasthenia gravis. Recently, the new automatic fluorescence assessment platform AKLIDES has been developed for immunofluorescence-based diagnostics of autoimmune diseases. In order to establish an AKLIDES procedure for the detection of MuSK-specific autoantibodies (anti-MuSK), we developed a recombinant HEp-2 cell clone expressing the human MuSK cDNA. Here we show at the mRNA and protein level that the cell clone HEp-2 M4 stably expresses human MuSK. We provide evidence for a localization of MuSK at the cell membrane. Using cell clone HEp-2 M4 on the AKLIDES system, we investigated 34 patient sera that were previously tested anti-MuSK positive by radioimmunoassay as positive controls. As negative controls, we tested 29 acetylcholine receptor-positive but MuSK-negative patient sera, 30 amytrophic lateral sclerosis (ALS) patient sera and 45 blood donors. HEp-2 M4 cells revealed a high specificity for the detection of MuSK autoantibodies from 25 patient sera assessed by a specific pattern on HEp-2 M4 cells. By using appropriate cell culture additives, the fraction of cells stained positive with anti-MuSK containing sera can be increased from 2–16% to 10–48%, depending on the serum. In conclusion, we provide data showing that the novel recombinant cell line HEp-2 M4 can be used to screen for anti-MuSK with the automatic AKLIDES system. PMID:24416182

  17. Major motor-functional determinants associated with poor self-reported health-related quality of life in myasthenia gravis patients.

    PubMed

    Cioncoloni, David; Casali, Stefania; Ginanneschi, Federica; Carone, Marisa; Veronica, Boni; Rossi, Alessandro; Giannini, Fabio

    2016-05-01

    Myasthenia gravis (MG) is an autoimmune neuromuscular disorder in which disabling muscle weakness may affect health-related quality of life (HRQoL). The aim of this study was to investigate which common motor-functional deficits and corresponding severity are most determinant of poor HRQoL in these patients. In 41 patients, the dichotomized first item of the Italian Myasthenia Gravis Questionnaire (IMGQ), categorizing patients who report "good" and "poor" HRQoL, was chosen as dependent-outcome variable. All items composing the myasthenia gravis-specific scale (MG-ADL), i.e. talking, chewing, swallowing, breathing, impairment of ability to brush teeth or comb hair, impairment of ability to rise from chair, double vision, and eyelid droop were acquired as independent variables and dichotomized. Stepwise backward LR multivariable logistic regression analysis was performed. In addition, the main characteristics of patients were compared. MG-ADL items "chewing" ≥1, i.e. "fatigue chewing solid food", and "breathing" ≥2, i.e. "shortness of breath at rest" proved to be significant determinants. Higher dose of corticosteroid therapy was significantly (p = 0.027; r s  = -0.35), correlated with poor HRQoL. At diagnosis, a decremental response to repetitive nerve stimulation (RNS) from the abductor pollicis brevis was significantly more frequent in patients with poor HRQoL. In conclusion, impaired "chewing" and "breathing" functions indicate the need for careful planning of rehabilitation, re-education and patient management. Moreover, decremental response to RNS at diagnosis may identify patients at risk for poor HRQoL. PMID:27038315

  18. Genome-Wide Association Study of Late-Onset Myasthenia Gravis: Confirmation of TNFRSF11A and Identification of ZBTB10 and Three Distinct HLA Associations

    PubMed Central

    Seldin, Michael F; Alkhairy, Omar K; Lee, Annette T; Lamb, Janine A; Sussman, Jon; Pirskanen-Matell, Ritva; Piehl, Fredrik; Verschuuren, Jan J G M; Kostera-Pruszczyk, Anna; Szczudlik, Piotr; McKee, David; Maniaol, Angelina H; Harbo, Hanne F; Lie, Benedicte A; Melms, Arthur; Garchon, Henri-Jean; Willcox, Nicholas; Gregersen, Peter K; Hammarstrom, Lennart

    2015-01-01

    To investigate the genetics of late-onset myasthenia gravis (LOMG), we conducted a genome-wide association study imputation of >6 million single nucleotide polymorphisms (SNPs) in 532 LOMG cases (anti–acetylcholine receptor [AChR] antibody positive; onset age ≥50 years) and 2,128 controls matched for sex and population substructure. The data confirm reported TNFRSF11A associations (rs4574025, P = 3.9 × 10−7, odds ratio [OR] 1.42) and identify a novel candidate gene, ZBTB10, achieving genome-wide significance (rs6998967, P = 8.9 × 10−10, OR 0.53). Several other SNPs showed suggestive significance including rs2476601 (P = 6.5 × 10−6, OR 1.62) encoding the PTPN22 R620W variant noted in early-onset myasthenia gravis (EOMG) and other autoimmune diseases. In contrast, EOMG-associated SNPs in TNIP1 showed no association in LOMG, nor did other loci suggested for EOMG. Many SNPs within the major histocompatibility complex (MHC) region showed strong associations in LOMG, but with smaller effect sizes than in EOMG (highest OR ~2 versus ~6 in EOMG). Moreover, the strongest associations were in opposite directions from EOMG, including an OR of 0.54 for DQA1*05:01 in LOMG (P = 5.9 × 10−12) versus 2.82 in EOMG (P = 3.86 × 10−45). Association and conditioning studies for the MHC region showed three distinct and largely independent association peaks for LOMG corresponding to (a) MHC class II (highest attenuation when conditioning on DQA1), (b) HLA-A and (c) MHC class III SNPs. Conditioning studies of human leukocyte antigen (HLA) amino acid residues also suggest potential functional correlates. Together, these findings emphasize the value of subgrouping myasthenia gravis patients for clinical and basic investigations and imply distinct predisposing mechanisms in LOMG. PMID:26562150

  19. Myasthenia Gravis, Lambert-Eaton Myasthenic Syndrome & Congenital Myasthenic Syndromes

    MedlinePlus

    ... In most cases of MG, the immune system origins of MG have gradually unfolded, targets the acetylcholine ... is a rare autoimmune disease whose symptoms and origins are some- what similar to those of MG. ...

  20. Membranous nephropathy, leiomyoma and autoimmune myasthenia: more than a coincidence?

    PubMed

    Calviño, Jesus; Adeva, Magdalena; Sobrido, Maria-Jesus

    2012-12-01

    Membranous nephropathy (MN) has been associated with several infectious, immunological and malignant conditions, but had only rarely been reported with malignant and other immune disorders in the same patient. We describe the case of a 56-year-old male with MN who was also diagnosed with a gastrointestinal stromal tumour (GIST), myasthenia gravis (MG) and thymic hyperplasia. Thus, we report here for the first time the coincidence of these conditions in the same patient. There was a recurrence of nephrotic syndrome without impairment of renal function 5 years after removal of the GIST (3 years after thymectomy). The possible basis for the relationship between these diseases is discussed, and some common genetic and immune physiopathological pathways are hypothesized. PMID:26069802

  1. Membranous nephropathy, leiomyoma and autoimmune myasthenia: more than a coincidence?

    PubMed Central

    Calviño, Jesus; Adeva, Magdalena; Sobrido, Maria-Jesus

    2012-01-01

    Membranous nephropathy (MN) has been associated with several infectious, immunological and malignant conditions, but had only rarely been reported with malignant and other immune disorders in the same patient. We describe the case of a 56-year-old male with MN who was also diagnosed with a gastrointestinal stromal tumour (GIST), myasthenia gravis (MG) and thymic hyperplasia. Thus, we report here for the first time the coincidence of these conditions in the same patient. There was a recurrence of nephrotic syndrome without impairment of renal function 5 years after removal of the GIST (3 years after thymectomy). The possible basis for the relationship between these diseases is discussed, and some common genetic and immune physiopathological pathways are hypothesized. PMID:26069802

  2. Serum uric acid levels in patients with myasthenia gravis are inversely correlated with disability

    PubMed Central

    Yang, Dehao; Weng, Yiyun; Lin, Haihua; Xie, Feiyan; Yin, Fang; Lou, Kangliang; Zhou, Xuan; Han, Yixiang; Li, Xiang

    2016-01-01

    Uric acid (UA), the final product of purine metabolism, has been reported to be reduced in patients with various neurological disorders and is considered to be a possible indicator for monitoring the disability and progression of multiple sclerosis. However, it remains unclear whether there is a close relationship between UA and myasthenia gravis (MG), or whether UA is primarily deficient or secondarily reduced because of its peroxynitrite scavenging activity. We investigated the correlation between serum UA levels and the clinical characteristics of MG. We assessed 338 serum UA levels obtained in 135 patients with MG, 47 patients with multiple sclerosis, and 156 healthy controls. In addition, we compared serum UA levels when MG patients were stratified according to disease activity and classifications performed by the Myasthenia Gravis Foundation of America, age of onset, duration, and thymus histology (by means of MRI or computed tomography). MG patients had significantly lower serum UA levels than the controls (P<0.001). Moreover, UA levels in patients with MG were inversely correlated with disease activity and disease progression (P=0.013). However, UA levels did not correlate significantly with disease duration, age of onset, and thymus histology. Our findings suggest that serum level of UA was reduced in patients with MG and serum UA might be considered a surrogate biomarker of MG disability and progression. PMID:26836463

  3. [Reversal of rocuronium induced neuromuscular block with sugammadex in a patient with myasthenia gravis].

    PubMed

    Nakamori, Erisa; Nitahara, Keiichi; Sugi, Yasuyuki; Katori, Kiyoshi; Matsuzaki, Akiko; Higa, Kazuo

    2013-08-01

    We report a patient with myasthenia gravis whose rocuronium induced neuromuscular block was reversed with sugammadex. A 26-year-old man, 175 cm and 76 kg, with myasthenia gravis, was scheduled for extended thymectomy under general anesthesia. An epidural catheter was inserted at the T5-6 interspace before induction of general anesthesia. Anesthesia was induced with propofol and remifentanil. Rocuronium was given in divided doses to obtain > 95% neuromuscular block to intubate the trachea. The ED50 and ED95 of rocuronium for this patient were 0.18 mg x kg(-1) and 0.39 mg x kg(-1), respectively. The values were similar to the ED50 and ED95 of rocuronium for normal patients. General anesthesia was maintained with propofol and remifentanil. Additional doses of rocuronium were given intermittently. Sugammadex, 2 mg x kg(-1), was given at the end of the surgery. The train-of-four ratio reached 93% 105 sec later. His postoperative course was uneventful. PMID:23984578

  4. Mechanisms of acetylcholine receptor loss in myasthenia gravis.

    PubMed Central

    Drachman, D B; Adams, R N; Stanley, E F; Pestronk, A

    1980-01-01

    The fundamental abnormality affecting the neuromuscular junctions of myasthenic patients is a reduction of available AChRs, due to an autoimmune attack directed against the receptors. Antibodies to AChR are present in most patients, and there is evidence that they have a predominant pathogenic role in the disease, aided by complement. The mechanism of antibody action involves acceleration of the rate of degradation of AChRs, attributable to cross-linking of the receptors. In addition, antibodies may block AChRs, and may participate in producing destructive changes, perhaps in conjunction with complement. The possibility that cell-mediated mechanisms may play a role in the autoimmune responses of some myasthenic patients remains to be explored. Although the target of the autoimmune attack in myasthenic patients is probably always the acetylcholine receptors, it is not yet clear which of these immune mechanisms are most important. It is likely that the relative role of each mechanism varies from patient to patient. One of the goals of future research will be to identify the relative importance of each of these mechanisms in the individual patient, and to tailor specific immunotherapeutic measures to the abnormalities found. PMID:6249894

  5. T-cell receptor V sub. alpha. and C sub. alpha. alleles associated with multiple sclerosis and myasthenia gravis

    SciTech Connect

    Oksenberg, J.R.; Cavalli-Sforza, L.L.; Steinman, L. ); Sherritt, M.; Bernard, C.C. ); Begovich, A.B.; Erlich, H.A. )

    1989-02-01

    Polymorphic markers in genes encoding the {alpha} chain of the human T-cell receptor (TcR) have been detected by Southern blot analysis in Pss I digests. Polymorphic bands were observed at 6.3 and 2.0 kilobases (kb) with frequencies of 0.30 and 0.44, respectively, in the general population. Using the polymerase chain reaction (PCR) method, the authors amplified selected sequences derived from the full-length TcR {alpha} cDNA probe. These PcR products were used as specific probes to demonstrate that the 6.3-kb polymorphic fragment hybridizes to the variable (V)-region probe and the 2.0-kb fragment hybridizes to the constant (C)-region probe. Segregation of the polymorphic bands was analyzed in family studies. To look for associations between these markers and autoimmune diseases, the authors have studied the restriction fragment length polymorphism distribution of the Pss I markers in patients with multiple sclerosis, myasthenia gravis, and Graves disease. Significant differences in the frequency of the polymorphic V{sub {alpha}} and C{sub {alpha}} markers were identified between patients and healthy individuals.

  6. [Recent advance in research for myasthenia gravis, in relation to various antibodies affecting synaptic structure and function].

    PubMed

    Takamori, Masaharu

    2009-11-01

    Autoantibodies impair acetylcholine receptor (AChR) in myasthenia gravis (MG) and P/Q-type voltage-gated calcium channel (VGCC) in Lambert-Eaton myasthenic syndrome (LEMS). (1) Some of MG and LEMS patients are "seronegative" for respective antibodies or modified by antibodies that recognize other proteins than AChR and VGCC such as MuSK, AChR allosteric site, membrane Na+ channel and ryanodine receptor-1 (RyR1) in MG, and synaptotagmin-1 in LEMS. (2) Autoimmune responses affect the proteins participating in the mechanisms to compensate for synaptic disorders on the basis of presynaptic Ca2+ homeostasis provided by VGCC and non-VGCC (receptor-operated TRPCs): they act as enhancers of Ca(2+) -mediated ACh release via phospholipase C signaling pathways including M1-type presynaptic muscarinic AChR, neurotrophin receptor (TrkB), and fast-mode of synaptic vesicle recycling. (3) The pathophysiology contributive to contractile fatigue in MG includes RyR1 and also TRPC3. The TRPC3 also forms a complex with STIM1 and Orail to make up for Ca2+ after sarcoplasmic Ca2+ release. The prevalent detection of anti-TRPC3 antibodies in MG with thymoma could affect muscle contractile machineries in addition to anti-RyR1-induced affection. (4) When one faces "seronegative" MG, one should be cautious to conformation-specific antibodies and also congenital myasthenic syndromes. PMID:20030211

  7. Blood Transcriptome Profiling in Myasthenia Gravis Patients to Assess Disease Activity: A Pilot RNA-seq Study

    PubMed Central

    Park, Kee Hong; Jung, Junghee; Lee, Jung-Hee

    2016-01-01

    Myasthenia gravis (MG) is an antibody-mediated autoimmune disease characterized by exertional weakness. There is no biomarker to reflect disease activity and guide treatment decision. Here, we reported a pilot blood transcriptome study using RNA sequencing (RNA-seq) that identified differences of 5 samples in active status and 5 in remission from 8 different patients and 2 patients provided samples for both active and remission phase. We found a total of 28 differentially expressed genes (DEGs) possibly related to disease activity (23 up-regulated and 5 down-regulated). The DEGs were enriched for the cell motion and cell migration processes in which included were ICAM1, CCL3, S100P and GAB2. The apoptosis and cell death pathway was also significantly enriched, which includes NFKBIA, ZC3H12A, TNFAIP3, and PPP1R15A. Our result suggests that transcript abundance profiles of the genes involved in cell trafficking and apoptosis may be a molecular signature of the disease activity in MG patients. PMID:26924932

  8. Flow Cytofluorimetric Analysis of Anti-LRP4 (LDL Receptor-Related Protein 4) Autoantibodies in Italian Patients with Myasthenia Gravis

    PubMed Central

    Marino, Mariapaola; Scuderi, Flavia; Samengo, Daniela; Saltelli, Giorgia; Maiuri, Maria Teresa; Shen, Chengyong; Mei, Lin; Sabatelli, Mario; Pani, Giovambattista; Antonini, Giovanni; Evoli, Amelia; Bartoccioni, Emanuela

    2015-01-01

    Background Myasthenia gravis (MG) is an autoimmune disease in which 90% of patients have autoantibodies against the muscle nicotinic acetylcholine receptor (AChR), while autoantibodies to muscle-specific tyrosine kinase (MuSK) have been detected in half (5%) of the remaining 10%. Recently, the low-density lipoprotein receptor-related protein 4 (LRP4), identified as the agrin receptor, has been recognized as a third autoimmune target in a significant portion of the double sero-negative (dSN) myasthenic individuals, with variable frequency depending on different methods and origin countries of the tested population. There is also convincing experimental evidence that anti-LRP4 autoantibodies may cause MG. Methods The aim of this study was to test the presence and diagnostic significance of anti-LRP4 autoantibodies in an Italian population of 101 myasthenic patients (55 dSN, 23 AChR positive and 23 MuSK positive), 45 healthy blood donors and 40 patients with other neurological diseases as controls. All sera were analyzed by a cell-based antigen assay employing LRP4-transfected HEK293T cells, along with a flow cytofluorimetric detection system. Results We found a 14.5% (8/55) frequency of positivity in the dSN-MG group and a 13% frequency of co-occurrence (3/23) in both AChR and MuSK positive patients; moreover, we report a younger female prevalence with a mild form of disease in LRP4-positive dSN-MG individuals. Conclusion Our data confirm LRP4 as a new autoimmune target, supporting the value of including anti-LRP4 antibodies in further studies on Myasthenia gravis. PMID:26284792

  9. Intravenous immunoglobulin-induced hemolytic anemia after thoracoscopic thymectomy for myasthenia gravis.

    PubMed

    Tsukada, Hisashi; Sunkara, Rajitha; Chi, Dorcas Doja; Keogh, Deirdre; Gaissert, Henning

    2014-06-01

    A 24-year-old woman underwent video-assisted thoracoscopic thymectomy for Osserman IIB myasthenia gravis (MG). In preparation for thymectomy, high-dose intravenous immunoglobulin (IVIG) was administered 1 week before the surgical procedure. After uneventful thoracoscopic thymectomy, the postoperative hemoglobin value decreased from 12.1 mg/dL to 8.2 mg/dL. A diagnosis of IVIG-associated hemolytic anemia was made based on a peripheral smear with numerous spherocytes, a positive direct antiglobulin test result, and increased reticulocyte count. Hemoglobin levels after IVIG administration should be monitored closely before and after elective surgical procedures to identify severe anemia. Transfusion of type-matched blood should be avoided and risk factors understood. PMID:24882299

  10. [A case of myasthenia gravis with transient taste disorders followed by aplastic anemia after thymectomy].

    PubMed

    Osada, Osamu; Iwasaki, Akira; Nakahashi, Hirotaka; Kim, Yoshitora; Kaneko, Kou

    2016-01-01

    A 45-year-old man was admitted to our hospital because of taste disorders in March 2014. He exhibited cervical muscle weakness and left eye ptosis, which responded to Tensilon test, and was diagnosed with myasthenia gravis (MG). He developed aspiration pneumonia and myasthenic crisis, which was treated with intravenous immunoglobulin and steroid pulse therapy. All symptoms disappeared. Oral administration of prednisolone and tacrolimus was started. Chest CT revealed thymoma and extended thymectomy was performed in May 2014. In December 2014, seven months after the thymectomy, hematological examination showed pancytopenia including severe neutropenia. We diagnosed his illness as aplastic anemia (AA). Cyclosporine therapy with transfusion was administerd and led to reticulocyte count recovery. Since May 2015, hemoglobin recovery reached a blood transfusion free period. To our knowledge, this is the first case report with the patient supposed of relationship among taste disorders, AA and thymoma-associated MG. PMID:26876109

  11. Nivolumab for the treatment of malignant melanoma in a patient with pre-existing myasthenia gravis

    PubMed Central

    Maeda, Osamu; Yokota, Kenji; Atsuta, Naoki; Katsuno, Masahisa; Akiyama, Masashi; Ando, Yuichi

    2016-01-01

    ABSTRACT A 79-year-old man with lymph node recurrence of malignant melanoma received nivolumab, an anti-programmed death 1 (PD-1) monoclonal antibody. He had pre-existing ocular myasthenia gravis (MG) and a continued small amount of corticosteroid. Grade 3 creatine phosphokinase elevation appeared after two doses of nivolumab, and the treatment was postponed until it improved to grade 1. After three doses of nivolumab, he experienced diplopia and facial muscle weakness which were consistent with an acute exacerbation of MG, and the symptoms relieved without additional treatment for MG. He achieved shrinkage of metastasis after ten doses of nivolumab. Although a case who died due to MG after administration of nivolumab was reported recently, pre-existing MG is considered not to be always a contraindication of nivolumab. PMID:27019533

  12. Rapid Return of Spontaneous Respiration after General Anesthesia with Sugammadex in a Patient with Myasthenia Gravis

    PubMed Central

    Kim, Raing Kyu; Kim, Soon Yul

    2016-01-01

    Myasthenia gravis causes weakness and fatigue of the skeletal muscles, including respiratory muscles. When immobile surgical fields are needed, neuromuscular blocking agents (NMBAs) are often administered to block muscle activity, leading to an immobile surgical field and respiratory arrest. Acetylcholinesterase inhibitors are administered to reverse the muscle block, promoting spontaneous respiration for patient recovery. If immobile surgical fields are required in myasthenic patient operations, NMBAs should be administered. However, recovery from NMBAs using acetylcholinesterase inhibitors might be delayed in myasthenic patients due to their intake of medicines that already inhibit cholinesterase, resulting in a delay in spontaneous respiration. Sugammadex is a recently introduced medicine that reverses muscle blocks through a different mechanism from acetylcholinesterase inhibitors and can be administered to facilitate the return of spontaneous respiration in myasthenic patients. Our experience of the rapid return to spontaneous respiration of a myasthenic patient with Sugammadex is reported in this paper. PMID:27358839

  13. The psychosocial impact of ptosis as a symptom of Myasthenia Gravis: a qualitative study.

    PubMed

    Richards, Hollie Sarah; Jenkinson, Elizabeth; Rumsey, Nichola; Harrad, Richard A

    2014-08-01

    The aim of this qualitative study was to investigate the psychosocial impact of ptosis as a symptom of Myasthenia Gravis (MG). Participants were recruited from a MG patient group on Facebook. 166 participants answered a series of open ended questions examining the impact of ptosis, and responses were analysed using Inductive Thematic Analysis, which revealed four main themes. The first highlighted the extent to which ptosis impacted negatively on psychosocial functioning. The second related to ways in which ptosis can be framed in a positive way, eg, as a believable symptom. The final two themes revealed the complex inter-relationships between functional and appearance-related impacts, and a desire from many participants for health care professionals to provide more support directly related to their ptosis. This study suggests that ptosis impacts in ways not currently recognized in literature and practice. PMID:24832459

  14. Guidelines for pre-clinical assessment of the acetylcholine receptor--specific passive transfer myasthenia gravis model-Recommendations for methods and experimental designs.

    PubMed

    Kusner, Linda L; Losen, Mario; Vincent, Angela; Lindstrom, Jon; Tzartos, Socrates; Lazaridis, Konstantinos; Martinez-Martinez, Pilar

    2015-08-01

    Antibodies against the muscle acetylcholine receptor (AChR) are the most common cause of myasthenia gravis (MG). Passive transfer of AChR antibodies from MG patients into animals reproduces key features of human disease, including antigenic modulation of the AChR, complement-mediated damage of the neuromuscular junction, and muscle weakness. Similarly, AChR antibodies generated by active immunization in experimental autoimmune MG models can subsequently be passively transferred to other animals and induce weakness. The passive transfer model is useful to test therapeutic strategies aimed at the effector mechanism of the autoantibodies. Here we summarize published and unpublished experience using the AChR passive transfer MG model in mice, rats and rhesus monkeys, and give recommendations for the design of preclinical studies in order to facilitate translation of positive and negative results to improve MG therapies. PMID:25743217

  15. Life-threatening misdiagnosis of bulbar onset myasthenia gravis as a motor neuron disease: How much can one rely on exaggerated deep tendon reflexes

    PubMed Central

    Basiri, Keivan; Ansari, Behnaz; Okhovat, Ali Asghar

    2015-01-01

    The autoimmune disease myasthenia gravis (MG), can mimic a variety of neurological disorders leading to a delay in diagnosis and treatment. On occasions, misdiagnosis of MG could lead to unnecessary therapeutic interventions. We report the case of a 50 year-old man, in whom MG was mistaken for motor neuron disease (MND). Subsequently, correct diagnosis and optimal management resulted in saving his life and significant improvement in his functional status. We discuss the importance of considering MG as one of the potential differential diagnoses among cases of new onset or recurrent unexplained bulbar symptoms, despite exaggerated deep tendon reflexes. Also, a literature review on the misdiagnosis of MG and the potential pitfalls in MG diagnosis are discussed. PMID:25802827

  16. The clinical absolute and relative scoring system-a quantitative scale measuring myasthenia gravis severity and outcome used in the traditional Chinese medicine.

    PubMed

    Liu, Guo-Chao; Gao, Bu-Lang; Yang, Hong-Qi; Qi, Guo-Yan; Liu, Peng

    2014-10-01

    Myasthenia gravis (MG) is a chronic autoimmune disease caused by autoantigen against the nicotine acetylcholine receptor at the neuromuscular junction. With modern treatment facilities, the treatment effect and outcome for MG has been greatly improved with MG and non-MG patients enjoying the same life expectancy. Many classifications of disease distribution and severity have been set up and tested all over the world, mainly in the western world. However, the absolute and relative scoring system for evaluating the severity and treatment effect of MG in China where traditional Chinese medicine (TCM) has been practiced for thousands of years has not been introduced worldwide. The TCM has achieved a great success in the treatment of MG in the country with a huge population. This article serves to introduce this scoring system to the world. PMID:25440379

  17. Altered Active Zones, Vesicle Pools, Nerve Terminal Conductivity, and Morphology during Experimental MuSK Myasthenia Gravis

    PubMed Central

    Patel, Vishwendra; Oh, Anne; Voit, Antanina; Sultatos, Lester G.; Babu, Gopal J.; Wilson, Brenda A.; Ho, Mengfei; McArdle, Joseph J.

    2014-01-01

    Recent studies demonstrate reduced motor-nerve function during autoimmune muscle-specific tyrosine kinase (MuSK) myasthenia gravis (MG). To further understand the basis of motor-nerve dysfunction during MuSK-MG, we immunized female C57/B6 mice with purified rat MuSK ectodomain. Nerve-muscle preparations were dissected and neuromuscular junctions (NMJs) studied electrophysiologically, morphologically, and biochemically. While all mice produced antibodies to MuSK, only 40% developed respiratory muscle weakness. In vitro study of respiratory nerve-muscle preparations isolated from these affected mice revealed that 78% of NMJs produced endplate currents (EPCs) with significantly reduced quantal content, although potentiation and depression at 50 Hz remained qualitatively normal. EPC and mEPC amplitude variability indicated significantly reduced number of vesicle-release sites (active zones) and reduced probability of vesicle release. The readily releasable vesicle pool size and the frequency of large amplitude mEPCs also declined. The remaining NMJs had intermittent (4%) or complete (18%) failure of neurotransmitter release in response to 50 Hz nerve stimulation, presumably due to blocked action potential entry into the nerve terminal, which may arise from nerve terminal swelling and thinning. Since MuSK-MG-affected muscles do not express the AChR γ subunit, the observed prolongation of EPC decay time was not due to inactivity-induced expression of embryonic acetylcholine receptor, but rather to reduced catalytic activity of acetylcholinesterase. Muscle protein levels of MuSK did not change. These findings provide novel insight into the pathophysiology of autoimmune MuSK-MG. PMID:25438154

  18. Selective response to rituximab in a young child with MuSK-associated myasthenia gravis.

    PubMed

    Govindarajan, Raghav; Iyadurai, Stanley J; Connolly, Anne; Zaidman, Craig

    2015-08-01

    Neuromuscular junction disorders in children are either genetic, such as congenital myasthenic syndrome, or autoimmune with circulating antibodies most commonly against acetylcholine receptors. There is limited experience recognizing and treating children with myasthenia associated with muscle-specific tyrosine kinase antibodies. We report a seven-year-old child with intermittent esotropia since age 3 months, and two years of progressive and severe diplopia, dysarthria, dysphagia, and facial weakness. Acetylcholine receptor antibodies and genetic testing for congenital myasthenic syndrome were negative. Muscle specific tyrosine kinase antibodies were significantly elevated. Ophthalmoplegia and bulbar weakness were refractory to treatment with acetylcholinesterase inhibitors, corticosteroids and IVIg but completely resolved following treatment with rituximab. Her neurologic examination remained normal at the most recent follow-up, 15 months after initiation of rituximab. Children with MuSK myasthenia, like adults, can respond to rituximab despite long standing disease and failure to improve on other immunosuppressant medications. PMID:25998611

  19. Myasthenia gravis associated with thymoma and toxic multinodular goiter. A case report.

    PubMed

    lonescu, Lidia; Stefănescu, Cipriana; Dănilă, R; Trifescu, Irina; Savin, M; Dragomir, C; Ferariu, D; Vulpoi, Carmen

    2012-01-01

    Adequate antithyroid drug treatment or surgery usually generates remission of myasthenia gravis (MG) in patients with thymus hyperplasia associated with Graves' hyperthyroidism. The case of a 46-year-old woman diagnosed with MG based on the clinical picture, anticholinesterase drug test and positive electromyography (EMG) is presented. The cervico-thoracic computer tomography revealed a compressive nodular goiter and normal antero-superior mediastinum and led to the diagnosis of MG secondary to the hyperthyroidism. An uneventful total thyroidectomy was performed, but postoperatively the MG symptoms worsened. TC99m tetrofosmin scintigraphy revealed an area of hyperfixation in the antero-inferior mediastinum, suggestive for thymoma, as confirmed by a repeated thoracic CT scan. Following a longitudinal sternotomy, a well incapsulated tumor of approximately 6/5 cm located in the antero-inferior mediastinum was found and an extensive thymomectomy was performed. The postoperative course was uneventful and the patient was discharged 9 days later with complete remission of myasthenia. The pathology report of the specimen revealed a mixt thymoma or AB thymoma after Muller-Hermelink and WHO classification, with invasive capsular foci corresponding to Masaoka II stadium. In conclusion, scintigraphy proved to be useful in the diagnosis and decision making of a thymoma. PMID:23077950

  20. T-lymphocyte-rich Thymoma and Myasthenia Gravis in a Siberian Tiger (Panthera tigris altaica)☆

    PubMed Central

    Allan, K.; Masters, N.; Rivers, S.; Berry, K.; Routh, A.; Lamm, C.

    2014-01-01

    Summary A 10-year-old captive male Siberian tiger (Panthera tigris altaica) presented with acute onset collapse, vomiting and dyspnoea, preceded by a 6-month period of progressive muscle wasting. Following humane destruction, post-mortem examination revealed a large multilobulated mass in the cranial mediastinum, which was diagnosed as a T-lymphocyte-rich thymoma with the aid of immunohistochemistry. Retrospective serology for acetylcholine receptor antibodies (titre 3.90 nmol/l) confirmed a diagnosis of thymoma-associated myasthenia gravis. Thymomas are reported rarely in wild carnivores, but when detected they appear to be similar in morphology to those seen in domestic carnivores and may also be accompanied by paraneoplastic syndromes. The clinical signs of myasthenia gravis in the tiger were consistent with those reported in cats and dogs and the condition is proposed as an important differential diagnosis for generalized weakness in captive Felidae. PMID:24444818

  1. Acute Respiratory Failure Induced by Magnesium Replacement in a 62-Year-Old Woman with Myasthenia Gravis.

    PubMed

    Singh, Paramveer; Idowu, Olakunle; Malik, Imrana; Nates, Joseph L

    2015-10-01

    Magnesium is known to act at the neuromuscular junction by inhibiting the presynaptic release of acetylcholine and desensitizing the postsynaptic membrane. Because of these effects, magnesium has been postulated to potentiate neuromuscular weakness. We describe the case of a 62-year-old woman with myasthenia gravis and a metastatic thymoma who was admitted to our intensive care unit for management of a myasthenic crisis. The patient's neuromuscular weakness worsened in association with standard intravenous magnesium replacement, and the exacerbated respiratory failure necessitated intubation, mechanical ventilation, and an extended stay in the intensive care unit. The effect of magnesium replacement on myasthenia gravis patients has not been well documented, and we present this case to increase awareness and stimulate research. In addition, we discuss the relevant medical literature. PMID:26504451

  2. Acute Respiratory Failure Induced by Magnesium Replacement in a 62-Year-Old Woman with Myasthenia Gravis

    PubMed Central

    Singh, Paramveer; Idowu, Olakunle; Malik, Imrana

    2015-01-01

    Magnesium is known to act at the neuromuscular junction by inhibiting the presynaptic release of acetylcholine and desensitizing the postsynaptic membrane. Because of these effects, magnesium has been postulated to potentiate neuromuscular weakness. We describe the case of a 62-year-old woman with myasthenia gravis and a metastatic thymoma who was admitted to our intensive care unit for management of a myasthenic crisis. The patient's neuromuscular weakness worsened in association with standard intravenous magnesium replacement, and the exacerbated respiratory failure necessitated intubation, mechanical ventilation, and an extended stay in the intensive care unit. The effect of magnesium replacement on myasthenia gravis patients has not been well documented, and we present this case to increase awareness and stimulate research. In addition, we discuss the relevant medical literature. PMID:26504451

  3. Factors that determine the severity of experimental myasthenia gravis.

    PubMed

    Drachman, D B; McIntosh, K R; Yang, B

    1998-05-13

    R antibody production than T cells with specificity for other Torpedo AChR epitopes. This results in production of greater amounts of AChR antibodies, including a critical subset that cross-reacts with autologous mouse AChR. The higher autoantibody levels contribute to the greater susceptibility to EAMG and to the greater severity of manifestations in the B6 strain compared with the bm12 strain. (4) There is a bias in B6 mice toward the production of AChR antibodies of IgG2b isotype. We suggest that T cells specific for alpha 146-162 may contribute to this isotype bias. The IgG2b antibodies appear to have particularly potent "myasthenogenic" effects in rats and mice. (5) Finally, it should be emphasized that these differences in immunological and clinical aspects of EAMG in B6 and bm12 mice are relative rather than absolute. T cells that respond to AChR epitopes other than alpha 146-162 can also provide help for AChR antibody production, albeit less potent. In a sense, this model represents a special case of molecular mimicry. In this case, the source of the foreign antigenic molecule is injection rather than the more usual route of infection. The antigen (Torpedo AChR) is one that these mice would never naturally encounter, and the critical amino acid (lysine 155) of the key epitope (alpha 146-162) is present only in the AChR of electric organs of electric fish and not in the AChR of mice, chickens, cows, or humans. The important point is that a detail of the structure of the foreign antigen--that is, a particular peptide of Torpedo AChR--can determine the severity of an antibody-mediated autoimmune disease, depending on how it interacts with a detail of the structure of the MHC Class II molecule and, in turn, on how the peptide/MHC Class II complex interacts with the available T cell repertoire. (ABSTRACT TRUNCATED) PMID:9668247

  4. Myasthenia gravis

    MedlinePlus

    ... symptoms and other medicines have not worked well. Crisis situations are attacks of weakness of the breathing ... may also be used to help end the crisis. This procedure involves removing the clear part of ...

  5. Myasthenia Gravis

    MedlinePlus

    ... due to weakness of the muscles that control eye movements, unstable or waddling gait, a change in facial ... neurological examinations. The physician looks for impairment of eye movements or muscle weakness without any changes in the ...

  6. Myasthenia Gravis

    MedlinePlus

    ... symptoms are trouble with eye and eyelid movement, facial expression and swallowing. But it can also affect other muscles. The weakness gets worse with activity, and better with rest. There are medicines to ...

  7. Myasthenia gravis

    MedlinePlus

    ... breathing assistance with a ventilator . A procedure called plasmapheresis may also be used to help end the ... is free of antibodies, or with other fluids. Plasmapheresis may also help reduce symptoms for 4 to ...

  8. Comparative effects of plasma exchange and pyridostigmine on respiratory muscle strength and breathing pattern in patients with myasthenia gravis.

    PubMed Central

    Goti, P.; Spinelli, A.; Marconi, G.; Duranti, R.; Gigliotti, F.; Pizzi, A.; Scano, G.

    1995-01-01

    BACKGROUND--Pyridostigmine, an acetylcholinesterase antagonist, is useful in improving respiratory function in patients with myasthenia gravis. More recently, plasma exchange has been employed in myasthenia gravis because it acts presumably by removal of circulating antibodies against acetylcholine receptors. Surprisingly, comparative data on the effects of pyridostigmine and plasma exchange on lung volumes, respiratory muscle strength, and ventilatory control system in patients with myasthenia gravis are lacking. METHODS--Nine consecutive patients with grade IIb myasthenia gravis were studied under control conditions and after a therapeutic dose of pyridostigmine. In a second study the patients were re-evaluated a few days after a cycle of plasma exchange, before taking pyridostigmine. In each subject pulmonary volumes, inspiratory (MIP) and expiratory (MEP) muscle force, and respiratory muscle strength, calculated as average MIP and MEP as percentages of their predicted values, were measured. The ventilatory control system was evaluated in terms of volume (tidal volume, VT) and time (inspiratory time, TI, and total time, TTOT) components of the respiratory cycle. Mean inspiratory flow (VT/TI)--that is, the "driving"--and TI/TTOT--that is, the "timing"--components of ventilation were also measured. RESULTS--In each patient treatment relieved weakness and tiredness, and dyspnoea grade was reduced with plasma exchange. Following treatment, vital capacity (VC) increased on average by 9.7% with pyridostigmine and by 14% with plasma exchange, and MIP increased by 18% and 26%, respectively. In addition, with plasma exchange but not with pyridostigmine forced expiratory volume in one second (FEV1) increased by 16% and MEP increased by 24.5%, while functional residual capacity (FRC) decreased a little (6.8%). The change in respiratory muscle strength was related to change in VC (r2 = 0.48). With plasma exchange, VT increased by 18.6% and VT/TI increased by 13.5%, while

  9. [A case of myasthenia gravis with invasive thymoma associated with diffuse panbronchiolitis, alopecia, dysgeusia, cholangitis and myositis].

    PubMed

    Maekawa, Risa; Shibuya, Hideki; Hideyama, Takuto; Shiio, Yasushi

    2014-01-01

    A 43-year-old man was admitted to our hospital because of diplopia, ptosis, and dysphagia that had begun three years previously. He was diagnosed with myasthenia gravis (MG) and invasive thymoma and treated with corticosteroid, thymectomy, and radiation therapy. Ten years after the thymectomy, computed tomography (CT) showed metastasis of the thymoma in the left lower lobe of the lung. Two years after this recurrence, when the patient was 55, respiratory symptoms such as wheezing, persistent cough, and dyspnea appeared. Chronic sinusitis, diffuse centrilobular opacities on CT, and positivity for HLA-B54 led to a diagnosis of diffuse panbronchiolitis (DPB). Despite treatment with clarithromycin, the respiratory symptoms worsened. The patient developed alopecia and body hair loss at the age of 56 followed by dysgeusia, cholangitis, and myositis with positivity for anti-Kv1.4 antibodies. Although treatment with an increased dose of corticosteroid improved hair loss, dysgeusia, cholangitis, and myositis, he died of progression of DPB and serious respiratory infection at the age of 58. In this case, various autoimmune disorders occurred together with MG as complications of thymoma. Although alopecia, dysgeusia, and myositis are already known as complications of MG associated with thymoma, cholangitis is not well-recognized since there have been few reports suggesting a causal relationship between cholangitis and thymoma. Furthermore, DPB caused by immunodeficiency and respiratory tract hypersensitivity associated with thymoma and HLA-B54, respectively, is the distinctive feature of our case. Neurologists should be aware that various organs can be damaged directly and indirectly by abnormal T cells from thymoma in patients with MG. PMID:25283823

  10. Late Onset Myasthenia Gravis Is Associated with HLA DRB1*15:01 in the Norwegian Population

    PubMed Central

    Maniaol, Angelina H.; Elsais, Ahmed; Lorentzen, Åslaug R.; Owe, Jone F.; Viken, Marte K.; Sæther, Hanne; Flåm, Siri T.; Bråthen, Geir; Kampman, Margitta T.; Midgard, Rune; Christensen, Marte; Rognerud, Anna; Kerty, Emilia; Gilhus, Nils Erik; Tallaksen, Chantal M. E.

    2012-01-01

    Background Acquired myasthenia gravis (MG) is a rare antibody-mediated autoimmune disease caused by impaired neuromuscular transmission, leading to abnormal muscle fatigability. The aetiology is complex, including genetic risk factors of the human leukocyte antigen (HLA) complex and unknown environmental factors. Although associations between the HLA complex and MG are well established, not all involved components of the HLA predisposition to this heterogeneous disease have been revealed. Well-powered and comprehensive HLA analyses of subgroups in MG are warranted, especially in late onset MG. Methodology/Principal Findings This case-control association study is of a large population-based Norwegian cohort of 369 MG patients and 651 healthy controls. We performed comprehensive genotyping of four classical HLA loci (HLA-A, -B, -C and -DRB1) and showed that the DRB1*15:01 allele conferred the strongest risk in late onset MG (LOMG; onset ≥60years) (OR 2.38, pc7.4×10−5). DRB1*13:01 was found to be a protective allele for both early onset MG (EOMG) and LOMG (OR 0.31, pc 4.71×10−4), a finding not previously described. No significant association was found to the DRB1*07:01 allele (pnc = 0.18) in a subset of nonthymomatous anti-titin antibody positive LOMG as reported by others. HLA-B*08 was mapped to give the strongest contribution to EOMG, supporting previous studies. Conclusion The results from this study provide important new information concerning the susceptibility of HLA alleles in Caucasian MG, with highlights on DRB1*15:01 as being a major risk allele in LOMG. PMID:22590574

  11. Direct Proof of the In Vivo Pathogenic Role of the AChR Autoantibodies from Myasthenia Gravis Patients

    PubMed Central

    Kordas, Gregory; Lagoumintzis, George; Sideris, Sotirios; Poulas, Konstantinos; Tzartos, Socrates J.

    2014-01-01

    Several studies have suggested that the autoantibodies (autoAbs) against muscle acetylcholine receptor (AChR) of myasthenia gravis (MG) patients are the main pathogenic factor in MG; however, this belief has not yet been confirmed with direct observations. Although animals immunized with AChR or injected with anti-AChR monoclonal Abs, or with crude human MG Ig fractions exhibit MG symptoms, the pathogenic role of isolated anti-AChR autoAbs, and, more importantly, the absence of pathogenic factor(s) in the autoAb-depleted MG sera has not yet been shown by in vivo studies. Using recombinant extracellular domains of the human AChR α and β subunits, we have isolated autoAbs from the sera of four MG patients. The ability of these isolated anti-subunit Abs and of the Ab-depleted sera to passively transfer experimental autoimmune MG in Lewis rats was investigated. We found that the isolated anti-subunit Abs were at least as efficient as the corresponding whole sera or whole Ig in causing experimental MG. Abs to both α- and β-subunit were pathogenic although the anti-α-subunit were much more efficient than the anti-β-subunit ones. Interestingly, the autoAb-depleted sera were free of pathogenic activity. The later suggests that the myasthenogenic potency of the studied anti-AChR MG sera is totally due to their anti-AChR autoAbs, and therefore selective elimination of the anti-AChR autoAbs from MG patients may be an efficient therapy for MG. PMID:25259739

  12. Regulation of acetylcholine receptor alpha subunit variants in human myasthenia gravis. Quantification of steady-state levels of messenger RNA in muscle biopsy using the polymerase chain reaction.

    PubMed Central

    Guyon, T; Levasseur, P; Truffault, F; Cottin, C; Gaud, C; Berrih-Aknin, S

    1994-01-01

    Myasthenia gravis (MG) is an autoimmune disease mediated by auto-antibodies that attack the nicotinic acetylcholine receptor (AChR). To elucidate the molecular mechanisms underlying the decrease in AChR levels at the neuromuscular junction, we investigated the regulation of AChR expression by analyzing mRNA of the two AChR alpha subunit isoforms (P3A+ and P3A-) in muscle samples from myasthenic patients relative to controls. We applied a quantitative method based on reverse transcription of total RNA followed by polymerase chain reaction (PCR), using an internal standard we constructed by site-directed mutagenesis. An increased expression of mRNA coding for the alpha subunit of the AChR isoforms was observed in severely affected patients (P < 0.003 versus controls) but not in moderately affected patients, independently of the anti-AChR antibody titer. Study of mRNA precursor levels indicates a higher expression in severely affected patients compared to controls, suggesting an enhanced rate of transcription of the message coding for the alpha subunit isoforms in these patients. We have also reported that mRNA encoding both isoforms are expressed at an approximate 1:1 ratio in controls and in patients. We have thus identified a new biological parameter correlated with disease severity, and provide evidence of a compensatory mechanism to balance the loss of AChR in human myasthenia gravis, which is probably triggered only above a certain degree of AChR loss. Images PMID:8040257

  13. Ocular myasthenia gravis: treatment successes and failures in patients with long-term follow-up.

    PubMed

    Kupersmith, Mark J

    2009-08-01

    We previously reported that prednisone reduced the frequency of generalized myasthenia (GMG) and controlled diplopia without major adverse effects at 2 years in patients with ocular myasthenia gravis (OMG). Questions remain as to whether study subjects had long-standing disease, biasing results towards a steroid benefit, and if prednisone merely delayed GMG onset. Here, we performed a record review of a referral neuro-ophthalmology service OMG database for patients who were followed-up for > or =4 years or until GMG developed. We studied the effect of prednisone on GMG incidence and control of ocular symptoms. Generally, patients with diplopia were recommended for prednisone therapy. Most remained on daily 2.5-10 mg for diplopia control. We compared the results for prednisone-treated and "untreated" (pyridostigmine only) patients. Of 87 patients, 55 were in the prednisone-treated and 32 were in the untreated groups. GMG developed in 7 (13%) of the prednisone-treated (OR 0.41; 95% CI 0.22-0.76) and in 16 (50%) of the untreated (OR 2.78; 95% CI 1.68-4.60) patients. After OMG onset, GMG developed at a mean 5.8 and 0.22 years in prednisone and untreated groups. Diplopia was present at the last exam in 27% of the prednisone-treated (mean 7.2 years) and in 57% of the untreated (mean 4.6 years) OMG patients. For 48 prednisone-treated patients who did not develop GMG, OMG treatment failure occurred in 13. Thus, prednisone delays the onset of GMG and has sustained benefit in reducing the incidence of GMG and controlling diplopia. Without prednisone, GMG develops in 50% of OMG patients, typically within 1 year. PMID:19377863

  14. Genetic heterogeneity within the HLA region in three distinct clinical subgroups of myasthenia gravis.

    PubMed

    Saruhan-Direskeneli, Güher; Hughes, Travis; Yilmaz, Vuslat; Durmus, Hacer; Adler, Adam; Alahgholi-Hajibehzad, Mahdi; Aysal, Fikret; Yentür, Sibel P; Akalin, Mehmet Ali; Dogan, Oner; Marx, Alexander; Gülsen-Parman, Yesim; Oflazer, Piraye; Deymeer, Feza; Sawalha, Amr H

    2016-05-01

    This study aims to investigate genetic susceptibility to early-onset and late-onset anti-acetylcholine receptor antibody positive myasthenia gravis (EOMG and LOMG) and anti-muscle specific kinase antibody positive MG (MuSK-MG) at genome-wide level in a single population. Using a custom-designed array and imputing additional variants and the classical HLA alleles in 398 patients, we detected distinct associations. In EOMG, rs113519545 in the HLA class I region (OR=5.71 [3.77-8.66], P=2.24×10(-16)), HLA-B*08:01 (OR=7.04 [3.95-12.52], P=3.34×10(-11)) and HLA-C*07:01 (OR=2.74 [1.97-3.81], P=2.07(-9)), in LOMG, rs111256513 in the HLA class II region (OR=2.22 [1.59-3.09], P=2.48×10(-6)) and in MuSK-MG, an intronic variant within HLA-DQB1 (rs68081734, OR=5.86, P=2.25×10(-14)) and HLA-DQB1*05:02 (OR=8.56, P=6.88×10(-13)) revealed the most significant associations for genome-wide significance. Differential genetic susceptibility within the HLA to EOMG, LOMG and MuSK-MG has been established in a population from Turkey. PMID:27181991

  15. Myasthenia gravis with muscle specific kinase antibodies mimicking amyotrophic lateral sclerosis.

    PubMed

    Huijbers, Maartje G; Niks, Erik H; Klooster, Rinse; de Visser, Marianne; Kuks, Jan B; Veldink, Jan H; Klarenbeek, Pim; Van Damme, Philip; de Baets, Marc H; van der Maarel, Silvère M; van den Berg, Leonard H; Verschuuren, Jan J

    2016-06-01

    Muscle-specific kinase (MuSK) myasthenia gravis (MG) is hallmarked by the predominant involvement of bulbar muscles and muscle atrophy. This might mimic amyotrophic lateral sclerosis (ALS) presenting with bulbar weakness. We encountered four cases of MuSK MG patients with an initial misdiagnosis of ALS. We analyzed the clinical data of the four misdiagnosed MuSK MG patients, and investigated the presence of MuSK autoantibodies in a group of 256 Dutch bulbar-onset ALS patients using a recombinant MuSK ELISA and a standard MuSK radioimmunorecipitation assay. Clues for changing the diagnosis were slow progression, clinical improvement, development of diplopia and absence of signs of upper motor neuron involvement. No cases of MuSK MG were identified among a group of 256 bulbar ALS patients diagnosed according to the revised El Escorial criteria. A misdiagnosis of ALS in patients with MuSK MG is rare. We recommend to carefully consider the diagnosis of MuSK MG in patients presenting with bulbar weakness without clear signs of upper motor neuron dysfunction. PMID:27133662

  16. [Intractable Myasthenia Gravis Accompanied with Thymoma;Report of a Case].

    PubMed

    Naomi, Akira; Oyamatsu, Yoshinori; Narita, Kunio; Nakayama, Masato; Maeda, Shoki

    2016-09-01

    A 46-year-old female visited a hospital due to pelvic inflammatory disease (PID) and then her chest computed tomography revealed an abnormal shadow in the upper mediastinum. Four months later,she complained muscle weakness with her limbs, dysphagia, and ptosis of her eyelids. Total thymectomy was performed through a median sternotomy for mass lesion, which was pathologically proven to be type B1 thymoma. Postoperative myasthenia gravis (MG) crisis, which led to respiratory failure requiring intubation and mechanical ventilation, developed and laboratory tests showed elevated serum anti-AChR Ab(130 nmol/l), antinuclear antibody( ×640 serum dilution, speckled pattern) and anti-RNP Ab(129.2 U/ml). For MG crisis, steroid pulse therapy, immunosuppressive therapy and immuno absorption were performed, and she successfully weaned from mechanical ventilaton on 41 post operative day (POD). Some factors such as inapparent mixed connective tissue disease (MCTD) and Anti RNP antibody were thought to be a cause for having any difficulty in MG treatment in the present case. PMID:27586323

  17. Diagnosis of Ocular Myasthenia Gravis by means of tracking eye parameters.

    PubMed

    Azri, Muhammad; Young, Stephanie; Lin, Hazel; Tan, Clement; Yang, Zhi

    2014-01-01

    Ptosis of the eyelids is a common condition with a myriad of causes. Its management depends on the underlying cause, which can be challenging to diagnose in some cases. Current diagnosis methods include serum antibodies, tensilon test, and electromyography (EMG). Each has its own set of limitations such as invasiveness and lack of sensitivity. To overcome these limitations, we have developed a Portable Realtime Infrared Lids, Iris and Blink (PRILIB) monitoring system, with a long-term goal to improve clinical diagnosis of ptosis. In this paper, we present the algorithms to detect and analyze eye parameters and report experimental results. From experiments conducted on normal volunteers and myasthenic patients, we found 1. Partial blinks happen when Ocular Myasthenia Gravis (OMG) patients are tired or engaged in an activity; 2. Blink rate is significantly higher for OMG patients due to failure to blink fully; 3. There are noticeably more fluctuations of palpebral aperture of OMG patients due to rising and falling of the eyelid height. These experimental findings suggest new diagnostic features for OMG patients and have implications for disease management. PMID:25570244

  18. Comparison of outcomes after extended thymectomy for myasthenia gravis: bilateral thoracoscopic approach versus sternotomy.

    PubMed

    Shiono, Hiroyuki; Kadota, Yoshihisa; Hayashi, Akio; Okumura, Meinoshin

    2009-12-01

    Minimally invasive thymectomy procedures have been proposed for nonthymomatous myasthenia gravis. However, few reports stressed that the lower invasiveness or cosmetic benefits also evaluated the rationale of a thymectomy, which is performed to remove as much thymic tissue as possible. We retrospectively reviewed 30 consecutive patients who underwent a bilateral video-assisted thoracoscopic extended thymectomy (VATET) and compared the results with those of 26 patients who underwent a transsternal extended thymectomy (TSET) to determine the amount of removed thymic tissue and clinical prognosis. The amount of blood loss during the operation for VATET (median 60 mL; range nearly 0 to 940 mL) was significantly lower as compared with that of TSET. The median weight of removed thymic tissue (37.0 g; 18.3 to 100.0 g) and remission rates (1 y: 12.5%; 3 y: 30.8%; 4 y: 44.4%) of VATET were comparable with those of TSET. The VATET group had a similar amount of thymo-fatty tissue removed and feasible clinical outcomes as compared with the TSET group, indicating that VATET provides a proper balance between less invasiveness and radical capability. PMID:20027081

  19. Phenotypic and functional characterization of T cells from patients with myasthenia gravis.

    PubMed Central

    Mokhtarian, F; Pino, M; Ofosu-Appiah, W; Grob, D

    1990-01-01

    A study of cell surface phenotypes of PBL of myasthenia gravis (MG) patients showed that their T cells had a significantly higher percentage of 4B4+ T cells (the helper/inducer subset) than age- and sex-matched controls. The PBL of MG patients proliferated significantly higher than those of normal subjects (NS) in response to the purified alpha chain of the acetylcholine receptor (AChR). Anti-AChR antibody was present in sera of 88% of MG and none of the NS. The PBL B cells from MG only, when cultured with autologous T cells and stimulated with either pokeweed mitogen (69%), or AChR-alpha chain (38%), secreted antibody to AChR-alpha chain, whereas T and B cells alone secreted no antibody. T cells from PBL of MG patients were more readily cloned than T cells of NS, by limiting dilution, in the presence of recombinant IL-2 and in the absence of AChR-alpha chain. About 50% of T cell clones from MG patients, compared to none from NS, proliferated to AChR-alpha chain. This response was HLA-DR restricted. MG T cell clones did not display significant cytotoxic activity, as compared to control T cell clones. Our results indicate that in MG, 4B4+ regulatory T cells play their role in the pathogenesis of MG, not by cytotoxicity, but more likely by their ability to stimulate specific antibody production by B cells. Images PMID:1979338

  20. A reliability study of impairment and disability scales for myasthenia gravis patients.

    PubMed

    Romani, Alfredo; Piccolo, Giovanni; Bergamaschi, Roberto; Versino, Maurizio; Cosi, Vittorio

    2002-01-01

    The authors developed two scales to be adopted for the evaluation of myasthenia gravis (MG) patients. The first scale (MG impairment scale) is based on objective patient evaluation and on patients' responses to standardized questions relating to the functioning of specific muscle groups. It consists of 13 items exploring strength and 10 items exploring fatigability. The second scale (MG disability scale) evaluates disability in those everyday activities that are often impaired in MG patients. Test-retest reliability of each item and of the global score (sum of single item scores) was assessed by the weighted K statistic and by the intraclass correlation coefficient. Reliability was invariably 'substantial', and for single items 'almost perfect' for the MG impairment scale, and invariably 'almost perfect' for the MG disability scale. The internal structure of the MG impairment scale was explored by means of the principal component analysis. This analysis resulted in three main (rotated) factors, which loaded respectively onto 'ocular', 'spinal' and 'bulbar' functions. For these factors, we report factor score coefficients that can be used to compute single patients' scores, which in turn may be used in further analyses, particularly for follow-up studies. We also report the results of an analysis of the correlations between the two scales. The MG impairment and the MG disability scales are proposed for application in both clinical and research settings. PMID:12549719

  1. Antibodies against low-density lipoprotein receptor-related protein 4 induce myasthenia gravis.

    PubMed

    Shen, Chengyong; Lu, Yisheng; Zhang, Bin; Figueiredo, Dwight; Bean, Jonathan; Jung, Jiung; Wu, Haitao; Barik, Arnab; Yin, Dong-Min; Xiong, Wen-Cheng; Mei, Lin

    2013-12-01

    Myasthenia gravis (MG) is the most common disorder affecting the neuromuscular junction (NMJ). MG is frequently caused by autoantibodies against acetylcholine receptor (AChR) and a kinase critical for NMJ formation, MuSK; however, a proportion of MG patients are double-negative for anti-AChR and anti-MuSK antibodies. Recent studies in these subjects have identified autoantibodies against low-density lipoprotein receptor-related protein 4 (LRP4), an agrin receptor also critical for NMJ formation. LRP4 autoantibodies have not previously been implicated in MG pathogenesis. Here we demonstrate that mice immunized with the extracellular domain of LRP4 generated anti-LRP4 antibodies and exhibited MG-associated symptoms, including muscle weakness, reduced compound muscle action potentials (CMAPs), and compromised neuromuscular transmission. Additionally, fragmented and distorted NMJs were evident at both the light microscopic and electron microscopic levels. We found that anti-LRP4 sera decreased cell surface LRP4 levels, inhibited agrin-induced MuSK activation and AChR clustering, and activated complements, revealing potential pathophysiological mechanisms. To further confirm the pathogenicity of LRP4 antibodies, we transferred IgGs purified from LRP4-immunized rabbits into naive mice and found that they exhibited MG-like symptoms, including reduced CMAP and impaired neuromuscular transmission. Together, these data demonstrate that LRP4 autoantibodies induce MG and that LRP4 contributes to NMJ maintenance in adulthood. PMID:24200689

  2. Antibodies against low-density lipoprotein receptor–related protein 4 induce myasthenia gravis

    PubMed Central

    Shen, Chengyong; Lu, Yisheng; Zhang, Bin; Figueiredo, Dwight; Bean, Jonathan; Jung, Jiung; Wu, Haitao; Barik, Arnab; Yin, Dong-Min; Xiong, Wen-Cheng; Mei, Lin

    2013-01-01

    Myasthenia gravis (MG) is the most common disorder affecting the neuromuscular junction (NMJ). MG is frequently caused by autoantibodies against acetylcholine receptor (AChR) and a kinase critical for NMJ formation, MuSK; however, a proportion of MG patients are double-negative for anti-AChR and anti-MuSK antibodies. Recent studies in these subjects have identified autoantibodies against low-density lipoprotein receptor–related protein 4 (LRP4), an agrin receptor also critical for NMJ formation. LRP4 autoantibodies have not previously been implicated in MG pathogenesis. Here we demonstrate that mice immunized with the extracellular domain of LRP4 generated anti-LRP4 antibodies and exhibited MG-associated symptoms, including muscle weakness, reduced compound muscle action potentials (CMAPs), and compromised neuromuscular transmission. Additionally, fragmented and distorted NMJs were evident at both the light microscopic and electron microscopic levels. We found that anti-LRP4 sera decreased cell surface LRP4 levels, inhibited agrin-induced MuSK activation and AChR clustering, and activated complements, revealing potential pathophysiological mechanisms. To further confirm the pathogenicity of LRP4 antibodies, we transferred IgGs purified from LRP4-immunized rabbits into naive mice and found that they exhibited MG-like symptoms, including reduced CMAP and impaired neuromuscular transmission. Together, these data demonstrate that LRP4 autoantibodies induce MG and that LRP4 contributes to NMJ maintenance in adulthood. PMID:24200689

  3. Thymectomy for myasthenia gravis: outcome of treatment in a tertiary hospital.

    PubMed

    Torres, M I; Danguilan, J L

    1998-08-01

    The clinical records of 24 of the 31 patients who underwent thymectomy for myasthenia gravis from January 1991 to December 1995 were reviewed. The mean age of patients was 36.5 years, with a male : female ratio of 1 : 5. The average duration of symptoms prior to consultation was 16.6 months. Most of the patients presented diplopia with clinical stage IIA prior to surgery. The most common procedure utilized was thymectomy via a median sternotomy under general anesthesia-epidural anesthesia. Five of the 24 patients (21%) were immediately extubated postoperatively while 19 remained intubated, with 12 patients attached to a ventilator. Extubation ranged from the first postoperative day up to more than two weeks postoperatively. The average length of ICU stay was 8.1 days and the average length of hospital stay was 31.1 days. The most common morbidity was pneumonia (38%). One patient had a brief reactive psychosis and another patient had phrenic nerve injury which manifested 2 weeks postoperatively. The average length of follow-up was 14.8 months and the mean follow-up period was 24.5 months. There was a general trend of decrease in the dose of medication. However, there was an increase in the medication in 3 patients with 2 showing clinical improvement. PMID:9738120

  4. Specific binding of collagen Q to the neuromuscular junction is exploited to cure congenital myasthenia and to explore bases of myasthenia gravis.

    PubMed

    Ohno, Kinji; Ito, Mikako; Kawakami, Yu; Krejci, Eric; Engel, Andrew G

    2013-03-25

    Acetylcholinesterase (AChE) at the neuromuscular junction (NMJ) is anchored to the synaptic basal lamina via a triple helical collagen Q (ColQ) in the form of asymmetric AChE (AChE/ColQ). The C-terminal domain of ColQ binds to MuSK, the muscle-specific receptor tyrosine kinase, that mediates a signal for acetylcholine receptor (AChR) clustering at the NMJ. ColQ also binds to heparan sulfate proteoglycans including perlecan. Congenital defects of ColQ cause endplate AChE deficiency. A single intravenous administration of adeno-associated virus serotype 8 (AAV8)-COLQ to Colq-/- mice rescued motor functions, synaptic transmission, and the ultrastructure of NMJ. We also injected AAV1-COLQ-IRES-EGFP to the left tibialis anterior and observed colocalization of AChE/ColQ at all the examined NMJs of the non-injected limbs. Additionally, injection of purified recombinant AChE/ColQ protein complex into gluteus maximus accumulated AChE in non-injected forelimbs. These observations suggest that the tissue-targeting signal of ColQ can be exploited to specifically deliver the transgene product to the target tissue. MuSK antibody-positive myasthenia gravis (MG) accounts for 5-15% of autoimmune MG. As AChR deficiency is typically mild and as cholinesterase inhibitors are generally ineffective or worsen myasthenic symptoms, we asked if the patient's MuSK-IgG interferes with binding of ColQ to MuSK. In vitro overlay of AChE/ColQ to muscle sections of Colq-/- mice revealed that MuSK-IgG blocks binding of ColQ to the NMJ. In vitro plate-binding of MuSK to ColQ disclosed that MuSK-IgG exerts a dose-dependent block of MuSK-ColQ interaction. In addition, passive transfer of MuSK-IgG to mice reduced the size and density of ColQ to ∼10% of controls and had a lesser effect on the sizes and densities of AChR and MuSK. Elucidation of molecular mechanisms of specific binding of ColQ to the NMJ enabled us to ameliorate devastating myasthenic symptoms of Colq-/- mice and to reveal bases of

  5. Specific binding of collagen Q to the neuromuscular junction is exploited to cure congenital myasthenia and to explore bases of myasthenia gravis

    PubMed Central

    Ohno, Kinji; Ito, Mikako; Kawakami, Yu; Krejci, Eric; Engel, Andrew G.

    2015-01-01

    Acetylcholinesterase (AChE) at the neuromuscular junction (NMJ) is anchored to the synaptic basal lamina via a triple helical collagen Q (ColQ) in the form of asymmetric AChE (AChE/ColQ). The C-terminal domain of ColQ binds to MuSK, the muscle-specific receptor tyrosine kinase, that mediates a signal for acetylcholine receptor (AChR) clustering at the NMJ. ColQ also binds to heparan sulfate proteoglycans including perlecan. Congenital defects of ColQ cause endplate AChE deficiency. A single intravenous administration of adeno-associated virus serotype 8 (AAV8)-COLQ to Colq−/− mice rescued motor functions, synaptic transmission, and the ultrastructure of NMJ. We also injected AAV1-COLQ-IRES-EGFP to the left tibialis anterior and observed colocalization of AChE/ColQ at all the examined NMJs of the non-injected limbs. Additionally, injection of purified recombinant AChE/ColQ protein complex into gluteus maximus accumulated AChE in non-injected forelimbs. These observations suggest that the tissue-targeting signal of ColQ can be exploited to specifically deliver the transgene product to the target tissue. MuSK antibody-positive myasthenia gravis (MG) accounts for 5–15% of autoimmune MG. As AChR deficiency is typically mild and as cholinesterase inhibitors are generally ineffective or worsen myasthenic symptoms, we asked if the patient's MuSK-IgG interferes with binding of ColQ to MuSK. In vitro overlay of AChE/ColQ to muscle sections of Colq−/− mice revealed that MuSK-IgG blocks binding of ColQ to the NMJ. In vitro plate-binding of MuSK to ColQ disclosed that MuSK-IgG exerts a dose-dependent block of MuSK-ColQ interaction. In addition, passive transfer of MuSK-IgG to mice reduced the size and density of ColQ to ~10% of controls and had a lesser effect on the sizes and densities of AChR and MuSK. Elucidation of molecular mechanisms of specific binding of ColQ to the NMJ enabled us to ameliorate devastating myasthenic symptoms of Colq−/− mice and to reveal

  6. Therapeutic target of memory B cells depletion helps to tailor administration frequency of rituximab in myasthenia gravis.

    PubMed

    Lebrun, Christine; Bourg, Véronique; Bresch, Saskia; Cohen, Mikael; Rosenthal-Allieri, Maria Alessandra; Desnuelle, Claude; Ticchioni, Michel

    2016-09-15

    Rituximab (RTX) has demonstrated efficacy in limiting relapses in myasthenia gravis (MG). We investigated the interest of CD27+ memory B cell monitoring in patients as a biological marker of clinical relapse. Twenty-four patients have been treated with RTX (375mg/m(2)/week-month as an induction treatment). Maintenance treatment consisted with either systematic treatment every 3months or only when CD27+ memory B cells were detectable. After the induction treatment, the mean infusions were 1.3/year compared with 4/year. We suggest that RTX administration frequency can be decreased safely by monitoring the re-emerging CD27+ memory B cells. PMID:27609279

  7. Rituximab in refractory myasthenia gravis: a prospective, open-label study with long-term follow-up.

    PubMed

    Anderson, Dustin; Phan, Cecile; Johnston, Wendy S; Siddiqi, Zaeem A

    2016-07-01

    We examined the clinical effectiveness of rituximab in fourteen patients with refractory myasthenia gravis (MG). Manual muscle testing (MMT) score was recorded at baseline and followed during the course of the study. Steroid dose, frequency of intravenous immunoglobulin (IVIG) infusions, and plasma exchange (PLEX) were also monitored throughout the duration of the study. All patients responded dramatically to rituximab, as measured by a change in MMT score, prednisone dose, or the frequency of IVIG infusions or PLEX. Rituximab appears safe and effective for the treatment of refractory MG. It should be considered as a therapeutic option in refractory patients. PMID:27386504

  8. The Association of PTPN22 R620W Polymorphism Is Stronger with Late-Onset AChR-Myasthenia Gravis in Turkey

    PubMed Central

    Kaya, Gizem A.; Coşkun, Ayse N.; Yılmaz, Vuslat; Oflazer, Piraye; Gülsen-Parman, Yeşim; Aysal, Fikret; Disci, Rian; Direskeneli, Haner; Marx, Alexander; Deymeer, Feza; Saruhan-Direskeneli, Güher

    2014-01-01

    A functional single nucleotide polymorphism (SNP) of the PTPN22 gene encoding a protein tyrosine phosphatase has been associated with autoimmune disorders including myasthenia gravis (MG). As the PTPN22 R620W polymorphism has a wide variation of allele frequencies among different populations, this polymorphism was investigated in MG in Turkey. An emphasis is put on MG subgroups according to autoantibody (Abs) production and presence of thymoma. DNA samples from 416 patients with clinically diagnosed generalized MG (231 with Abs to acetylcholine receptor, AChR-MG), 53 with Abs to muscle-specific kinase (MuSK-MG), 55 patients with no detectable Abs (SN-MG), 77 patients with thymoma (TAMG) and 293 healthy controls (HC) were genotyped for the SNP (PTPN22 R620W, C1858T, rs2476601). The PTPN22 T allele was increased in AChR-MG patients (odds ratio [OR]: 2.5, 95%CI: 1.2–5.1). The association was stronger in late disease-onset AChR (LOMG, OR: 3.1, 95%CI: 1.2–8.2). MuSK-MG, SN-MG and TAMG groups did not carry the variant allele more frequently than the HC. In contrast to findings in other autoimmune diseases, the distribution of the PTPN22 polymorphism in this population provides a susceptibility marker for AChR-MG. The strongest association is detected in patients with LOMG. PMID:25119822

  9. Blockade of CD40 ligand suppresses chronic experimental myasthenia gravis by down-regulation of Th1 differentiation and up-regulation of CTLA-4.

    PubMed

    Im, S H; Barchan, D; Maiti, P K; Fuchs, S; Souroujon, M C

    2001-06-01

    Myasthenia gravis (MG) and experimental autoimmune MG (EAMG) are T cell-dependent Ab-mediated autoimmune disorders, in which the nicotinic acetylcholine receptor (AChR) is the major autoantigen. Th1-type cells and costimulatory factors such as CD40 ligand (CD40L) contribute to disease pathogenesis by producing proinflammatory cytokines and by activating autoreactive B cells. In this study we demonstrate the capacity of CD40L blockade to modulate EAMG, and analyze the mechanism underlying this disease suppression. Anti-CD40L Abs given to rats at the chronic stage of EAMG suppress the clinical progression of the autoimmune process and lead to a decrease in the AChR-specific humoral response and delayed-type hypersensitivity. The cytokine profile of treated rats suggests that the underlying mechanism involves down-regulation of AChR-specific Th1-regulated responses with no significant effect on Th2- and Th3-regulated AChR-specific responses. EAMG suppression is also accompanied by a significant up-regulation of CTLA-4, whereas a series of costimulatory factors remain unchanged. Adoptive transfer of splenocytes from anti-CD40L-treated rats does not protect recipient rats against subsequently induced EAMG. Thus it seems that the suppressed progression of chronic EAMG by anti-CD40L treatment does not induce a switch from Th1 to Th2/Th3 regulation of the AChR-specific immune response and does not induce generation of regulatory cells. The ability of anti-CD40L treatment to suppress ongoing chronic EAMG suggests that blockade of CD40L may serve as a potential approach for the immunotherapy of MG and other Ab-mediated autoimmune diseases. PMID:11359850

  10. Response to suxamethonium during propofol-fentanyl-N2O/O2 anaesthesia in a patient with active myasthenia gravis receiving long-term anticholinesterase therapy.

    PubMed

    Vanlinthout, L E; Robertson, E N; Booij, L H

    1994-06-01

    We describe the effect of repeated suxamethonium doses during propofol-fentanyl-N2O/O2 anaesthesia in a 29-year-old woman with active myasthenia gravis receiving chronic pyridostigmine therapy. Despite adequate pre-operative pseudocholinesterase activity, suxamethonium resistance occurred. Neither bradycardia nor residual neuromuscular block were seen after repeated doses of suxamethonium. PMID:8017595