301
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Gilhus NE, Owe JF, Hoff JM, Romi F, Skeie GO, Aarli JA. Myasthenia gravis: a review of available treatment approaches. Autoimmune Dis 2011; 2011:847393. [PMID: 22007295 PMCID: PMC3189457 DOI: 10.4061/2011/847393] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2011] [Accepted: 08/11/2011] [Indexed: 11/26/2022] Open
Abstract
Patients with autoimmune myasthenia gravis (MG) should be further classified before initiating therapy, as treatment response varies for ocular versus generalised, early onset versus late onset, and acetylcholine receptor antibody positive versus MuSK antibody positive disease. Most patients need immunosuppression in addition to symptomatic therapy. Prednisolone and azathioprine represent first choice drugs, whereas several second choice options are recommended and should be considered. Thymectomy should be undertaken in MG with thymoma and in generalised, early-onset MG. For MG crises and other acute exacerbations, intravenous immunoglobulin (IvIg) and plasma exchange are equally effective and safe treatments. Children and females in child bearing age need special attention regarding potential side effects of immunosuppressive therapy. MG pathogenesis is known in detail, but the immune therapy is still surprisingly unspecific, without a pin-pointed attack on the defined disease-inducing antigen-antibody reaction being available.
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Affiliation(s)
- Nils Erik Gilhus
- Department of Clinical Medicine, University of Bergen, 5020 Bergen, Norway
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302
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Rezania K, Soliven B, Baron J, Lin H, Penumalli V, van Besien K. Myasthenia gravis, an autoimmune manifestation of lymphoma and lymphoproliferative disorders: case reports and review of literature. Leuk Lymphoma 2011; 53:371-80. [PMID: 21864038 DOI: 10.3109/10428194.2011.615426] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Kourosh Rezania
- Department of Neurology, University of Chicago Medical Center, Chicago, IL 60637, USA.
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303
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Allman W, Saini SS, Tuzun E, Christadoss P. Characterization of peripheral blood acetylcholine receptor-binding B cells in experimental myasthenia gravis. Cell Immunol 2011; 271:292-8. [PMID: 21861992 DOI: 10.1016/j.cellimm.2011.07.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 06/16/2011] [Accepted: 07/12/2011] [Indexed: 12/20/2022]
Abstract
In myasthenia gravis (MG), the neuromuscular transmission is impaired by antibodies (Abs) specific for muscle acetylcholine receptor (AChR). Anti-AChR Abs can be detected in the serum of MG patients, although their levels do not correlate with disease severity. In this study, we developed a flow cytometric assay for the detection of peripheral blood AChR-specific B cells to characterize B cell phenotypes associated with experimental autoimmune myasthenia gravis (EAMG). Alexa-conjugated AChR was used as a probe for AChR-specific B cells (B220+Ig+). Mice with EAMG had significantly elevated frequencies of AChR-specific IgG2+ and IgM+ B cells. While the frequencies of IgG2+ B cells and plasma anti-AChR IgG2 levels significantly correlated with the clinical grades of EAMG, the frequencies of IgM+ B cells and plasma anti-AChR IgM levels did not. These results indicate that the frequency of AChR-specific and IgG1+ (mouse IgG2 equivalent) peripheral blood B cells and anti-AChR IgG1 levels could be potential biomarkers for MG disease severity.
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Affiliation(s)
- Windy Allman
- Department of Microbiology and Immunology, The University of Texas Medical Branch, Galveston, TX 77555-1070, United States
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304
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Liu Y, Wang W, Li J. Evaluation of Serum IgG Subclass Concentrations in Myasthenia Gravis Patients. Int J Neurosci 2011; 121:570-4. [DOI: 10.3109/00207454.2011.596293] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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305
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Vincent A. Autoantibodies in neuromuscular transmission disorders. Ann Indian Acad Neurol 2011; 11:140-5. [PMID: 19893659 PMCID: PMC2771981 DOI: 10.4103/0972-2327.42932] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2008] [Accepted: 07/21/2008] [Indexed: 12/20/2022] Open
Abstract
It is a great pleasure to be asked to honour the memory of Dr. Baldev Singh by reviewing the field of autoantibodies in myasthenia gravis and other neurotransmission disorders. The neuromuscular junction (NMJ) is the site of a number of different autoimmune and genetic disorders, and it is also the target of many neurotoxins from venomous snakes, spiders, scorpions and other species. The molecular organization of the NMJ is graphically represented in Figure 1A, where different ion channels, receptors and other proteins are shown. Four of the ion channels or receptors are directly involved in autoimmune diseases. This brief review will not only concentrate on these conditions but also illustrate how their study is helping us to understand the etiology of rare but treatable neurological syndromes of the central nervous system.
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Affiliation(s)
- Angela Vincent
- Department of Clinical Neurology and Weatherall Institute of Molecular Medicine, University of Oxford, UK
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306
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Castrejón I, Shum K, Tseng CE, Askanase A. Association between myasthaenia gravis and systemic lupus erythematosus: three case reports and review of the literature. Scand J Rheumatol 2011; 40:486-90. [DOI: 10.3109/03009742.2011.575077] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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307
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Ren J, Bai Y, Hao L, Dong Y, Pi Z, Jia L. Amelioration of experimental autoimmune myasthenia gravis rats by blood purification treatment using 4-mercaptoethylpyridine-based adsorbent. J Biomed Mater Res A 2011; 98:589-95. [DOI: 10.1002/jbm.a.33139] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2010] [Revised: 03/04/2011] [Accepted: 04/19/2011] [Indexed: 11/07/2022]
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308
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Tüzün E, Huda R, Christadoss P. Complement and cytokine based therapeutic strategies in myasthenia gravis. J Autoimmun 2011; 37:136-43. [PMID: 21636248 DOI: 10.1016/j.jaut.2011.05.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2011] [Accepted: 05/02/2011] [Indexed: 01/17/2023]
Abstract
Myasthenia gravis (MG) is a T cell-dependent and antibody-mediated disease in which the target antigen is the skeletal muscle acetylcholine receptor (AChR). In the last few decades, several immunological factors involved in MG pathogenesis have been discovered mostly by studies utilizing the experimental autoimmune myasthenia gravis (EAMG) model. Nevertheless, MG patients are still treated with non-specific global immunosuppression that is associated with severe chronic side effects. Due to the high heterogeneity of AChR epitopes and antibody responses involved in MG pathogenesis, the specific treatment of MG symptoms have to be achieved by inhibiting the complement factors and cytokines involved in anti-AChR immunity. EAMG studies have clearly shown that inhibition of the classical and common complement pathways effectively and specifically diminish the neuromuscular junction destruction induced by anti-AChR antibodies. The inborn or acquired deficiencies of IL-6, TNF-α and TNF receptor functions are associated with the lowest EAMG incidences. Th17-type immunity has recently emerged as an important contributor of EAMG pathogenesis. Overall, these results suggest that inhibition of the complement cascade and the cytokine networks alone or in combination might aid in development of future treatment models that would reduce MG symptoms with highest efficacy and lowest side effect profile.
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Affiliation(s)
- Erdem Tüzün
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA
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309
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Abstract
PURPOSE The aim of this study was to determine the efficacy of thymectomy to induce remission in juvenile myasthenia gravis. METHODS A retrospective review of all patients undergoing a thymectomy for the treatment of juvenile myasthenia gravis was performed at a single tertiary referral centre between 1997 and 2009 (N = 8). All cases were moderate to severe cases (Osserman stage ≥ 2a). All operations were open. Median follow-up was 18 months (range 1-77). Postoperative progress was assessed using the De Filippi classification of remission. MAIN RESULTS Only two minor complications were reported. Mean operative time was 120 min (range 80-290 min). Mean postoperative stay was 17 days (range 3-52 days). Remission was observed in 5 of 8 patients (62%) at last known follow up. CONCLUSIONS Spontaneous remission rates for myasthenia gravis are quoted to be between 20 and 29% while remission rates following thymectomy are 29-68% at 3 years. Although not all of our patients have had 3 years of follow up-the remission rate of 62% demonstrated by this study is encouraging. If reproducible over a larger series this provides evidence of the efficacy of thymectomy for treating juvenile myasthenia gravis in selected patients.
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310
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Chien PJ, Yeh JH, Chiu HC, Hsueh YM, Chen CT, Chen MC, Shih CM. Inhibition of peripheral blood natural killer cell cytotoxicity in patients with myasthenia gravis treated with plasmapheresis. Eur J Neurol 2011; 18:1350-7. [DOI: 10.1111/j.1468-1331.2011.03424.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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311
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CD4+ CD25(high) regulatory T cell in childhood ocular myasthenia gravis. Brain Dev 2011; 33:442-4. [PMID: 20797828 DOI: 10.1016/j.braindev.2010.08.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Revised: 07/14/2010] [Accepted: 08/02/2010] [Indexed: 11/22/2022]
Abstract
Dysfunction of CD4(+)CD25(+) regulatory T cell (Treg) has been demonstrated to play an important role in the development of autoimmune myasthenia gravis. This T cell subset, which has potent regulatory properties against immune response, has been reported to have a numerical or functional defect in patients with myasthenia gravis. We examined various T cell subsets, including CD4(+)CD25(+)Treg in peripheral blood mononuclear cells using flow cytometry in a pediatric patient suffering from ocular myasthenia gravis. Contrary to previous reports, the percentage of CD4(+)CD25(+)Treg in peripheral blood decreased significantly after successful treatment with prednisolone. This discrepancy could result from diversity within the immunopathogenesis of myasthenia gravis and may underpin a particular subgroup of myasthenia gravis seen in the East-Asian pediatric population.
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312
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Na SJ, So SH, Lee KO, Choi YC. Elevated serum level of interleukin-32α in the patients with myasthenia gravis. J Neurol 2011; 258:1865-70. [PMID: 21487807 DOI: 10.1007/s00415-011-6036-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2011] [Revised: 03/10/2011] [Accepted: 03/31/2011] [Indexed: 10/18/2022]
Abstract
A new cytokine, interleukin-32 (IL-32), has been implicated in the pro-inflammatory immune responses in several autoimmune disorders, such as rheumatoid arthritis and inflammatory bowel diseases. Myasthenia gravis (MG) is a well-characterized autoimmune disease directed at the postsynaptic acetylcholine receptor (AChR) or end plate of the neuromuscular junction. IL-32 is a cytokine that induces tumor necrosis factor (TNF)-α, IL-6, IL-1β, and chemokine. IL-6, TNF-α, and IL-2 are related to the pathogenesis and immunoregulation of MG. The gene expression of IL-32 is increased in human natural killer (NK) cells and T lymphocytes when stimulated by IL-2 or mitogen. NK cells influence the development of experimental autoimmune MG (EAMG) and possibly MG. The aim of this study was to examine whether IL-32α levels are increased in patients with MG and to investigate the relationship between IL-32α levels and disease activity in human MG. Serum IL-32α levels were significantly higher in the MG patients (p = 0.03): 460.07 ± 192.30 pg/mL in MG patients and 248.45 ± 188.42 pg/mL in the healthy control group. Although there was no significant statistical difference, serum IL-32α levels of patients with both anti-AChR binding and blocking antibodies trended to be higher than those without either antibodies (521.56 ± 212.92 pg/mL vs. 339.52 ± 182.78 pg/mL, p = 0.16). IL-32α serum levels tended to decrease with clinical improvement in generalized MG. This study suggests the possibility that IL-32 might contribute to MG pathogenesis or immunoregulation.
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Affiliation(s)
- Sang-Jun Na
- Department of Neurology, Gangnam Severance Hospital, Brain Korea 21 Project for Medical Science, Yonsei University College of Medicine, 146-92 Gangnam-gu, Seoul, 135-720, Republic of Korea
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313
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Abstract
Myasthenia gravis (MG) is an antibody-mediated, neuromuscular transmission disorder, which ranges in clinical manifestations of ocular myasthenia that may be visually disabling to myasthenic crisis with patients suffering life-threatening respiratory insufficiency. MG also has pathophysiologic subgroups based on presence or absence of acetylcholine receptor or muscle-specific kinase antibodies and presence of thymoma. Cholinesterase inhibitors partially improve weakness, but the vast majority of patients require therapies that moderate the autoimmune attack. Mortality of MG has been reduced over the last century, but adverse effects of treatment compromise patient care and rigorous evidence to guide the clinician are lacking.
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314
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Noronha-Matos JB, Morais T, Trigo D, Timóteo MA, Magalhães-Cardoso MT, Oliveira L, Correia-de-Sá P. Tetanic failure due to decreased endogenous adenosine A(2A) tonus operating neuronal Ca(v) 1 (L-type) influx in Myasthenia gravis. J Neurochem 2011; 117:797-811. [PMID: 21323926 DOI: 10.1111/j.1471-4159.2011.07216.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In healthy motor endplates, tetanic depression is overcome by tonic adenosine A(2A) -receptor-mediated facilitation of transmitter release. The A(2A) receptor operates a coordinated shift from fast-desensitizing Ca(v) 2.1 (P/Q) calcium influx to long-lasting Ca(V) 1 (L) channels on motor nerve terminals. This study aimed at investigating whether A(2A) receptors-operated Ca(2+) influx via Ca(V) 1 (L)-type channels contribute to sustain acetylcholine release evoked by 50 Hz-bursts in toxin-induced Myasthenia gravis (TIMG) rats. In contrast to control animals, inhibition of [(3) H]acetylcholine (ACh) release by the Ca(V) 2.1 (P/Q) channel blocker, ω-Agatoxin IVA (100 nM), in TIMG rats had a higher magnitude than that observed with the Ca(V) 1 (L) channel blocker, nifedipine (1 μM). Adenosine deaminase (0.5 U/mL) and the A(2A) receptor antagonist, ZM 241385 (50 nM), decreased [(3) H]ACh release by a similar amount in control rats, but their effects were smaller in magnitude in myasthenic animals. The adenosine precursor, AMP (100 μM), increased (~40%) ACh release in both control and TIMG animals. Blockade of A(2A) , but not of A(1) , receptors prevented AMP-induced facilitation of transmitter release; nifedipine (1 μM) mimicked the effect of the A(2A) receptor antagonist. Video-microscopy studies designed to measure real-time transmitter exocytosis using the FM4-64 fluorescent dye fully supported radiochemical data. Thus, impairment of the adaptive shift from Ca(V) 2.1 (P/Q) to Ca(V) 1 (L) channels may contribute to tetanic failure in myasthenic rats. This parallels the reduction of adenosine A(2A) receptor tonus in TIMG animals, which might be restored by exogenous application of AMP.
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Affiliation(s)
- J B Noronha-Matos
- Laboratório de Farmacologia e Neurobiologia/UMIB, Instituto de Ciências Biomédicas de Abel Salazar, Universidade do Porto, L. Prof. Abel Salazar 2, Porto, Portugal
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315
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Rudzka-Nowak A, Piechota M. Anaesthetic management of a patient with myasthenia gravis for abdominal surgery using sugammadex. Arch Med Sci 2011; 7:361-4. [PMID: 22291783 PMCID: PMC3258733 DOI: 10.5114/aoms.2011.22094] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 08/05/2010] [Accepted: 08/13/2010] [Indexed: 12/19/2022] Open
Abstract
We report a case of a patient with tumor of the caecum with coexistent myasthenia gravis (a form according to Osserman II A), requiring general anesthesia for abdominal surgery. To reverse the neuromuscular block induced by vecuronium was used sugammadex.
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Affiliation(s)
- Alina Rudzka-Nowak
- Department of Anaesthesiology and Intensive Therapy, Military Medical Academy University Hospital in Lodz, Medical University of Lodz, Poland
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316
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Lee YS, Moon SS. A case of Sheehan's syndrome that manifested as bilateral ptosis. J Korean Med Sci 2011; 26:580-2. [PMID: 21468269 PMCID: PMC3069581 DOI: 10.3346/jkms.2011.26.4.580] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 12/08/2010] [Indexed: 11/20/2022] Open
Abstract
Hypothyroidism can cause a variety of signs and symptoms of the neuromuscular system. However, ptosis in a patient with hypothyroidism is very rare. We report here on a case of central hypothyroidism that was due to Sheehan's syndrome and it manifested as bilateral ptosis in a 51-yr-old woman. She complained of exertional dyspnea and weakness. About 25-yr ago, she had a history of severe postpartum vaginal bleeding. The laboratory studies demonstrated hypopituitarism with secondary hypothyroidism. The ptosis was improved by replacement of thyroid hormone. Hypothyroidism should be considered in the differential diagnosis of patients who manifest with ptosis and that prompt replacement of hormone can lead to a complete recovery.
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Affiliation(s)
- Young Sil Lee
- Department of Internal Medicine, College of Medicine, Dongguk University, 307 Dongdae-ro, Gyeongju, Korea.
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317
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Zambelis T, Kokotis P, Karandreas N. Repetitive nerve stimulation of facial and hypothenar muscles: relative sensitivity in different myasthenia gravis subgroups. Eur Neurol 2011; 65:203-7. [PMID: 21412008 DOI: 10.1159/000324915] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 02/06/2011] [Indexed: 11/19/2022]
Abstract
AIM To assess the utility of repetitive nerve stimulation (RNS) in facial and hypothenar muscles in the clinical groups of myasthenia gravis (MG). PATIENTS AND METHODS We performed RNS study in the orbicularis oculi (O.O.), nasalis and abductor digiti quinti (ADQ) in 115 consecutive myasthenic patients and classified them according to the classifications of the Myasthenia Gravis Foundation of America. Patients were classified into three groups: group 1, group 2 (IIa, IIIa and IVa) and group 3 (IIb, IIIb and IVb). RESULTS RNS was abnormal in 95 patients (82.6%): 78.3% in the O.O., 66.1% in the nasalis and 19.1% in the ADQ. Both facial muscles were statistically more sensitive than the ADQ in all groups of patients. RNS in the O.O. was more frequently abnormal than in the nasalis only in group 1. Sensitivity to acetylcholine antibodies in myasthenic patients was 84%. Acetylcholine receptor (AChR) and muscle-specific tyrosine kinase antibodies were present in 96.7% of the patients with abnormal RNS in both facial muscles. Single-fiber electromyogram (SFEMG) was abnormal in 91.3% of the tested patients. One of the three tests used for the diagnosis of MG (AChR antibodies, SFEMG, RNS) was abnormal in 99.1% of the patients. DISCUSSION O.O. is the most sensitive muscle in all groups of MG followed by nasalis, while the ADQ is the muscle with the lowest sensitivity. Facial muscles, especially the O.O., should be the first to be tested in MG. The negativity of all tests (RNS, AChR antibodies, SFEMG) should question the diagnosis of MG, even in the presence of symptoms consistent with MG.
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Affiliation(s)
- T Zambelis
- Department of Neurology, University of Athens, Aeghinition Hospital, Athens, Greece.
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318
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Singh J, Kaur H, Kaushik A, Peer S. A Review of Antisense Therapeutic Interventions for Molecular Biological Targets in Various Diseases. INT J PHARMACOL 2011. [DOI: 10.3923/ijp.2011.294.315] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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319
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Vrolix K, Niks EH, Le Panse R, van Ostaijen-ten Dam MM, Muris AH, Jol-van der Zijde CM, van Tol MJ, Losen M, Molenaar PC, van Zoelen EJ, Berrih-Aknin S, De Baets MH, Verschuuren JJ, Martínez-Martínez P. Reduced thymic expression of ErbB receptors without auto-antibodies against synaptic ErbB in myasthenia gravis. J Neuroimmunol 2011; 232:158-65. [DOI: 10.1016/j.jneuroim.2010.10.024] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Revised: 09/27/2010] [Accepted: 10/21/2010] [Indexed: 11/15/2022]
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320
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Aricha R, Feferman T, Scott HS, Souroujon MC, Berrih-Aknin S, Fuchs S. The susceptibility of Aire(-/-) mice to experimental myasthenia gravis involves alterations in regulatory T cells. J Autoimmun 2011; 36:16-24. [PMID: 21035305 DOI: 10.1016/j.jaut.2010.09.007] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Revised: 09/21/2010] [Accepted: 09/23/2010] [Indexed: 12/21/2022]
Abstract
The autoimmune regulator (Aire) is involved in the prevention of autoimmunity by promoting thymic expression of tissue restricted antigens which leads to elimination of self-reactive T cells. We found that Aire knockout (KO) mice as well as mouse strains that are susceptible to experimental autoimmune myasthenia gravis (EAMG) have lower thymic expression of acetylcholine receptor (AChR- the main autoantigen in MG), compared to wild type (WT) mice and EAMG-resistant mouse strains, respectively. We demonstrated that Aire KO mice have a significant and reproducible lower frequency of CD4+Foxp3+ cells and a higher expression of Th17 markers in their thymus, compared to wild type (WT) mice. These findings led us to expect that Aire KO mice would display increased susceptibility to EAMG. Surprisingly, when EAMG was induced in young (2 month-old) mice, EAMG was milder in Aire KO than in WT mice for several weeks until the age of about 5 months. However, when EAMG was induced in relatively aged (6 month-old) mice, Aire KO mice presented higher disease severity than WT controls. This age-related change in susceptibility to EAMG correlated with an elevated proportion of Treg cells in the spleens of young but not old KO, compared to WT mice, suggesting a role for peripheral Treg cells in the course of disease. Our observations point to a possible link between Aire and Treg cells and suggest an involvement for both in the pathogenesis of myasthenia.
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Affiliation(s)
- Revital Aricha
- Department of Immunology, The Weizmann Institute of Science, Rehovot, 76100 Israel
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321
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Roh HS, Lee SY, Yoon JS. Comparison of clinical manifestations between patients with ocular myasthenia gravis and generalized myasthenia gravis. KOREAN JOURNAL OF OPHTHALMOLOGY 2011; 25:1-7. [PMID: 21350687 PMCID: PMC3039188 DOI: 10.3341/kjo.2011.25.1.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Accepted: 08/31/2010] [Indexed: 01/22/2023] Open
Abstract
Purpose To compare the clinical manifestations between patients with ocular myasthenia gravis and those with generalized myasthenia gravis (MG). Methods The medical records of 71 patients diagnosed with MG between January 1995 and December 2007 were reviewed. Demographics, sensitivities of diagnostic methods, the presence of systemic autoimmune diseases, ophthalmic complications caused by MG, and treatments were evaluated and compared. Results Fourteen patients (20%) were diagnosed with ocular MG and 57 patients (80%) with generalized MG. Sensitivities of anti-acetylcholine receptor antibody and repetitive nerve stimulation tests were significantly higher in the generalized MG group (84%, 89%) compared to those in the ocular MG group (50%, 54%) (p = 0.011, p = 0.008). The sensitivity of the neostigmine test was the highest in both groups (98% of generalized MG, 79% of ocular MG), and the difference between the two groups was borderline significant (p = 0.058). The most common symptoms were ptosis and diplopia, and both groups presented with pain, blurred vision, and tearing. Systemic autoimmune disease was more prominent in the generalized MG group (21%) than in the ocular MG group (14%), and steroid therapy was used more frequently in the generalized MG group (82%) than in the ocular MG group (57%). Ophthalmic complications associated with long-term steroid treatment were more profound in the generalized MG (30%) compared to those of the ocular MG (21%). Conclusions The generalized MG group was associated with higher sensitivities to diagnostic tests, more systemic steroid use, higher ophthalmic complications caused by systemic autoimmune disease, and long-term steroid treatment compared to those of the ocular MG group.
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Affiliation(s)
- Hyun Seok Roh
- Department of Ophthalmology, Institute of Vision Research, Yonsei University College of Medicine, Seoul, Korea
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322
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Sorting receptor Rer1 controls surface expression of muscle acetylcholine receptors by ER retention of unassembled alpha-subunits. Proc Natl Acad Sci U S A 2010; 108:621-5. [PMID: 21187406 DOI: 10.1073/pnas.1001624108] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The nicotinic acetylcholine receptor of skeletal muscle is composed of five subunits that are assembled in a stepwise manner. Quality control mechanisms ensure that only fully assembled receptors reach the cell surface. Here, we show that Rer1, a putative Golgi-ER retrieval receptor, is involved in the biogenesis of acetylcholine receptors. Rer1 is expressed in the early secretory pathway in the myoblast line C2C12 and in mouse skeletal muscle, and up-regulated during myogenesis. Upon down-regulation of Rer1 in C2C12 cells, unassembled acetylcholine receptor α-subunits escape from the ER and are transported to the plasma membrane and lysosomes, where they are degraded. As a result, the amount of fully assembled receptor at the cell surface is reduced. In vivo Rer1 knockdown and genetic inactivation of one Rer1 allele lead to significantly smaller neuromuscular junctions in mice. Our data show that Rer1 is a functionally important unique factor that controls surface expression of muscle acetylcholine receptors by localizing unassembled α-subunits to the early secretory pathway.
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323
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Aguiar ADAX, Carvalho AF, Costa CMDC, Fernandes JMA, D'Almeida JAC, Furtado LETDA, Cunha FMBD. Myasthenia gravis in Ceará, Brazil: clinical and epidemiological aspects. ARQUIVOS DE NEURO-PSIQUIATRIA 2010; 68:843-8. [DOI: 10.1590/s0004-282x2010000600003] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2009] [Accepted: 06/08/2010] [Indexed: 11/22/2022]
Abstract
A retrospective chart review was performed on patients diagnosed as having myasthenia gravis in Ceará State, Brazil and who were followed from October 1981 to June 2009. Clinical and epidemiologic aspects were evaluated. In this work, 122 patients were studied, of whom 85 (69.7%) were females and 37 (30.3%) were males. The disease duration ranged from five months to 50 years (8.9±8.1 years). Age at the first symptoms varied from 0 to 74 years (31.9±14.4 years). The first main symptoms and signs were ptosis, diplopia and limb weakness. Generalized myasthenia was the most common clinical presentation, but 5.1% (n=6) persisted as ocular myasthenia. Thymectomy was performed in 42.6% (n=52) of myasthenic patients. A thymoma was present in 10 patients. Serum acetylcholine receptor (AChR) antibodies were present in 80% (n=20) of specimens tested. The data presented are similar to those of studies performed in other countries.
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324
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Nessi V, Nava S, Ruocco C, Toscani C, Mantegazza R, Antozzi C, Baggi F. Naturally occurring CD4+CD25+ regulatory T cells prevent but do not improve experimental myasthenia gravis. THE JOURNAL OF IMMUNOLOGY 2010; 185:5656-67. [PMID: 20881192 DOI: 10.4049/jimmunol.0903183] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In the current study, we investigated whether naturally occurring CD4(+)CD25(+) T cells, separated by immunomagnetic anti-CD4 and anti-CD25 Abs from naive animals, are able to protect from experimental autoimmune myasthenia gravis (EAMG) and modify the progression of ongoing disease when administered to Torpedo californica acetylcholine receptor (AChR)-immunized Lewis rats. Even though CD4(+)CD25(+) and CD4(+)CD25(high) T cell frequencies were similar in the spleens and lymph nodes of EAMG and healthy rats, we observed that CD4(+)CD25(+) T cells isolated from the spleens of naive animals inhibited in vitro the Ag-induced proliferation of T cell lines specific to the self-peptide 97-116 of the anti-AChR subunit (R97-116), an immunodominant and myasthenogenic T cell epitope, whereas CD4(+)CD25(+) T cells purified from the spleens of EAMG rats were less effective. CD4(+)CD25(+) T cells from EAMG rats expressed less forkhead box transcription factor P3 but more CTLA-4 mRNA than healthy rats. Naive CD4(+)CD25(+) T cells, obtained from naive rats and administered to T. californica AChR-immunized animals according to a preventive schedule of treatment, reduced the severity of EAMG, whereas their administration 4 wk postinduction of the disease, corresponding to the onset of clinical symptoms (therapeutic treatment), was not effective. We think that the exogenous administration of CD4(+)CD25(+) naive T cells prevents the early events underlying the induction of EAMG, events linked to the T cell compartment (Ag recognition, epitope spreading, and T cell expansion), but fails to ameliorate ongoing EAMG, when the IgG-mediated complement attack to the AChR at the neuromuscular junction has already taken place.
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Affiliation(s)
- Valeria Nessi
- Neurology IV, Neurological Institute Foundation Carlo Besta, Milan, Italy
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325
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Cole RN, Ghazanfari N, Ngo ST, Gervásio OL, Reddel SW, Phillips WD. Patient autoantibodies deplete postsynaptic muscle-specific kinase leading to disassembly of the ACh receptor scaffold and myasthenia gravis in mice. J Physiol 2010; 588:3217-29. [PMID: 20603331 PMCID: PMC2976017 DOI: 10.1113/jphysiol.2010.190298] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2010] [Accepted: 07/02/2010] [Indexed: 01/14/2023] Open
Abstract
The postsynaptic muscle-specific kinase (MuSK) coordinates formation of the neuromuscular junction (NMJ) during embryonic development. Here we have studied the effects of MuSK autoantibodies upon the NMJ in adult mice. Daily injections of IgG from four MuSK autoantibody-positive myasthenia gravis patients (MuSK IgG; 45 mg day(1)i.p. for 14 days) caused reductions in postsynaptic ACh receptor (AChR) packing as assessed by fluorescence resonance energy transfer (FRET). IgG from the patients with the highest titres of MuSK autoantibodies caused large (51-73%) reductions in postsynaptic MuSK staining (cf. control mice; P < 0.01) and muscle weakness. Among mice injected for 14 days with control and MuSK patient IgGs, the residual level of MuSK correlated with the degree of impairment of postsynaptic AChR packing. However, the loss of postsynaptic MuSK preceded this impairment of postsynaptic AChR. When added to cultured C2 muscle cells the MuSK autoantibodies caused tyrosine phosphorylation of MuSK and the AChR beta-subunit, and internalization of MuSK from the plasma membrane. The results suggest a pathogenic mechanism in which MuSK autoantibodies rapidly deplete MuSK from the postsynaptic membrane leading to progressive dispersal of postsynaptic AChRs. Moreover, maintenance of postsynaptic AChR packing at the adult NMJ would appear to depend upon physical engagement of MuSK with the AChR scaffold, notwithstanding activation of the MuSK-rapsyn system of AChR clustering.
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Affiliation(s)
- R N Cole
- Physiology, Anderson Stuart Bldg (F13), University of Sydney, NSW 2006 Australia
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326
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Sesarman A, Vidarsson G, Sitaru C. The neonatal Fc receptor as therapeutic target in IgG-mediated autoimmune diseases. Cell Mol Life Sci 2010; 67:2533-50. [PMID: 20217455 PMCID: PMC11115620 DOI: 10.1007/s00018-010-0318-6] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Revised: 01/29/2010] [Accepted: 02/12/2010] [Indexed: 01/01/2023]
Abstract
Therapy approaches based on lowering levels of pathogenic autoantibodies represent rational, effective, and safe treatment modalities of autoimmune diseases. The neonatal Fc receptor (FcRn) is a major factor regulating the serum levels of IgG antibodies. While FcRn-mediated half-life extension is beneficial for IgG antibody responses against pathogens, it also prolongs the serum half-life of IgG autoantibodies and thus promotes tissue damage in autoimmune diseases. In the present review article, we examine current evidence on the relevance of FcRn in maintaining high autoantibody levels and discuss FcRn-targeted therapeutic approaches. Further investigation of the FcRn-IgG interaction will not only provide mechanistic insights into the receptor function, but should also greatly facilitate the design of therapeutics combining optimal pharmacokinetic properties with the appropriate antibody effector functions in autoimmune diseases.
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Affiliation(s)
- Alina Sesarman
- Department of Dermatology, University of Freiburg, Hauptstrasse 7, 79104 Freiburg, Germany
| | - Gestur Vidarsson
- Department of Experimental Immunohematology, Sanquin Research and Landsteiner Laboratory, Amsterdam, The Netherlands
| | - Cassian Sitaru
- Department of Dermatology, University of Freiburg, Hauptstrasse 7, 79104 Freiburg, Germany
- Centre for Biological Signalling Studies (bioss), University of Freiburg, Freiburg, Germany
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327
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Helgeland G, Petzold A, Hoff JM, Gilhus NE, Plant GT, Romi FR. Anti-Heat Shock Protein 70 antibody levels are increased in myasthenia gravis and Guillain-Barré syndrome. J Neuroimmunol 2010; 225:180-3. [DOI: 10.1016/j.jneuroim.2010.04.024] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2010] [Revised: 04/19/2010] [Accepted: 04/30/2010] [Indexed: 10/19/2022]
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328
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Ho A, Michelson D, Aaen G, Ashwal S. Cerebral folate deficiency presenting as adolescent catatonic schizophrenia: a case report. J Child Neurol 2010; 25:898-900. [PMID: 20445197 DOI: 10.1177/0883073809343475] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Cerebral folate deficiency presents during infancy with irritability, deceleration of head growth, seizures, and progressive cognitive and motor impairment. Although low serum folate levels have been found in patients with schizophrenia, we describe the first case of cerebral folate deficiency presenting as catatonic schizophrenia. A 13-year-old previously healthy boy presented to our hospital with a 17-month history of schizophrenic symptoms with progressively worsening catatonia. On admission, he demonstrated near-complete mutism, frequent enuresis and encopresis, and severe psychomotor retardation. Our initial diagnostic evaluations, including brain magnetic resonance imaging, electroencephalogram, and routine metabolic tests, were normal. A lumbar puncture done to look for neurotransmitter defects or cerebral folate deficiency revealed low levels of 5-methyltetrahydrofolate (31 nmol/L; reference range, 40-150 nmol/L). He also had elevated titers of folate receptor-blocking antibodies. He was treated for the next 9 months with 5-formyltetrahydrofolate (folinic acid), but his catatonia was unchanged.
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Affiliation(s)
- Albert Ho
- Department of Pediatrics, Division of Pediatric Neurology, Loma Linda University School of Medicine, Loma Linda, California 92350, USA
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329
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Raggi A, Leonardi M, Mantegazza R, Casale S, Fioravanti G. Social support and self-efficacy in patients with Myasthenia Gravis: a common pathway towards positive health outcomes. Neurol Sci 2010; 31:231-5. [PMID: 19936879 DOI: 10.1007/s10072-009-0194-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2009] [Accepted: 11/03/2009] [Indexed: 11/24/2022]
Abstract
Social support and self-efficacy, that was defined as one's belief in one's capabilities to enact a certain behaviour, have a mediating effect on health outcomes and, by facilitating healthy behaviours and compliance to treatment, reduce morbidity and mortality. This pilot study aims to test whether social support and self-efficacy have a positive effect in improving health outcomes of patients with Myasthenia Gravis. 74 patients (mean age 48.1; 67.6% female) were enrolled and reported low self-efficacy and health status, but good perceived social support. Men reported better self-efficacy than women, and those living with a partner reported higher social support levels. No differences were found stratifying for disease onset, disease stage and patients' working situation. Self-efficacy and tangible support were independent predictors of mental health status. These results provide a preliminary indication that psychosocial interventions aimed to increase self-efficacy could positively mediate mental health status in myasthenic patients, especially among women.
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Affiliation(s)
- Alberto Raggi
- Neurology, Public Health and Disability Unit, Scientific Directorate, Neurological Institute C. Besta, IRCCS Foundation, Via Celoria 11, 20133 Milan, Italy.
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330
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Kusner LL, Kaminski HJ, Soltys J. Effect of complement and its regulation on myasthenia gravis pathogenesis. Expert Rev Clin Immunol 2010; 4:43-52. [PMID: 20477586 DOI: 10.1586/1744666x.4.1.43] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Myasthenia gravis (MG) is primarily caused by antibodies directed towards the skeletal muscle acetylcholine receptor, leading to muscle weakness. Although these antibodies may induce compromise of neuromuscular transmission by blocking acetylcholine receptor function or antigenic modulation, the predominant mechanism of injury to the neuromuscular junction is complement-mediated lysis of the postsynaptic membrane. The vast majority of data to support the role of complement derives from experimentally acquired MG (EAMG). In this article, we review studies that demonstrate the central role of complement in EAMG and MG pathogenesis along with the emerging role of complement in T- and B-cell function, as well as the potential for complement inhibitor-based therapy to treat human MG.
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Affiliation(s)
- Linda L Kusner
- Department of Neurology & Psychiatry, Saint Louis University, 1438 South Grand Blvd, St Louis, MO 63104, USA.
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331
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Shigemoto K, Kubo S, Mori S, Yamada S, Akiyoshi T, Miyazaki T. Muscle weakness and neuromuscular junctions in aging and disease. Geriatr Gerontol Int 2010; 10 Suppl 1:S137-47. [DOI: 10.1111/j.1447-0594.2010.00608.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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332
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Zhang LY, Wang W, Feng YK, Liu YH, Wang QS. Analysis of peripheral blood dendritic cell subtypes in thymomatous MG. Scand J Immunol 2010; 71:468-73. [PMID: 20500700 DOI: 10.1111/j.1365-3083.2010.02399.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The object of this work was to measure the levels of monocyte-derived dendritic cell precursors (pDC1) and plasmacytoid dendritic cell precursors (pDC2) in peripheral blood mononuclear cells (PBMC) of patients with thymomatous MG and to assess the ratio of pDC1/pDC2 in these patients. Three-colour monoclonal antibody labelling technology was used to detect the cell counts and ratio of pDC1 and pDC2 in PBMCs of 18 patients with myasthenia gravis (MG), nine thymomatous patients without MG, and 15 normal controls. The number of pDC and pDC subsets in peripheral blood of patients with thymomatous generalized MG was significantly lower than that in thymomatous controls before and after the treatment. After the treatment, patients with both generalized MG and ocular MG had significantly lower number of pDC compared with thymomatous controls. We found no significant differences in pDC1/pDC2 ratio among groups. Before the extended thymomatous treatment, the number of pDC in patients with generalized MG was significantly lower than that in patients with ocular MG (P < 0.05). The counts of peripheral blood pDC and pDC subsets of patients with thymomatous MG were significantly lower 1 week after extended thymectomy. The counts of pDC and pDC subsets decreased in generalized thymomatous MG, and the patients with generalized MG had lower pDC counts than the patients with ocular MG before the treatment. Treatment resulted in decreased counts of pDC and pDC subsets in thymomatous MG. We suggest that the level of peripheral blood pDC can be used as a marker to define the progress of the disease.
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Affiliation(s)
- L-Y Zhang
- Department of Thoracic Surgery, The 2nd Affiliated Hospital of Harbin Medical University, Harbin, China
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333
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Abstract
We recently described a severe, potentially lethal, but treatment-responsive encephalitis that associates with autoantibodies to the NMDA receptor (NMDAR) and results in behavioral symptoms similar to those obtained with models of genetic or pharmacologic attenuation of NMDAR function. Here, we demonstrate that patients' NMDAR antibodies cause a selective and reversible decrease in NMDAR surface density and synaptic localization that correlates with patients' antibody titers. The mechanism of this decrease is selective antibody-mediated capping and internalization of surface NMDARs, as Fab fragments prepared from patients' antibodies did not decrease surface receptor density, but subsequent cross-linking with anti-Fab antibodies recapitulated the decrease caused by intact patient NMDAR antibodies. Moreover, whole-cell patch-clamp recordings of miniature EPSCs in cultured rat hippocampal neurons showed that patients' antibodies specifically decreased synaptic NMDAR-mediated currents, without affecting AMPA receptor-mediated currents. In contrast to these profound effects on NMDARs, patients' antibodies did not alter the localization or expression of other glutamate receptors or synaptic proteins, number of synapses, dendritic spines, dendritic complexity, or cell survival. In addition, NMDAR density was dramatically reduced in the hippocampus of female Lewis rats infused with patients' antibodies, similar to the decrease observed in the hippocampus of autopsied patients. These studies establish the cellular mechanisms through which antibodies of patients with anti-NMDAR encephalitis cause a specific, titer-dependent, and reversible loss of NMDARs. The loss of this subtype of glutamate receptors eliminates NMDAR-mediated synaptic function, resulting in the learning, memory, and other behavioral deficits observed in patients with anti-NMDAR encephalitis.
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334
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Luo J, Kuryatov A, Lindstrom JM. Specific immunotherapy of experimental myasthenia gravis by a novel mechanism. Ann Neurol 2010; 67:441-51. [PMID: 20437579 DOI: 10.1002/ana.21901] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Myasthenia gravis (MG) and its animal model, experimental autoimmune myasthenia gravis (EAMG), are antibody (Ab)-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 the 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 alpha1 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.
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Affiliation(s)
- Jie Luo
- Department of Neuroscience, University of Pennsylvania Medical School, Philadelphia, PA 19104-6074, USA
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335
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Long-acting anticholinesterases for myasthenia gravis: synthesis and activities of quaternary phenylcarbamates of neostigmine, pyridostigmine and physostigmine. Bioorg Med Chem 2010; 18:4687-93. [PMID: 20627738 DOI: 10.1016/j.bmc.2010.05.022] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Revised: 05/05/2010] [Accepted: 05/06/2010] [Indexed: 11/20/2022]
Abstract
The N-monophenylcarbamate analogues of neostigmine methyl sulfate (6) and pyridostigmine bromide (8) together with their precursors (5), (7), and the N(1)-methylammonium analogues of (-)-phenserine (12), (-)-tolserine (14), (-)-cymserine (16) and (-)-phenethylcymserine (18) were synthesized to produce long-acting peripheral inhibitors of acetylcholinesterase or butyrylcholinesterase. Evaluation of their cholinesterase inhibition against human enzyme ex vivo demonstrated that, whereas compounds 5-8 possessed only marginal activity, 12, 14, 16 and 18 proved to be potent anticholinesterases. An extended duration of cholinesterase inhibition was determined in rodent, making them of potential interest as long-acting agents for myasthenia gravis.
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336
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Keefe D, Parng C, Lundberg D, Ray S, Martineau-Bosco J, Leng C, Tzartos S, Powell J, Concino M, Heartlein M, Lamsa J, Josiah S. In vitrocharacterization of an acetylcholine receptor–transferrin fusion protein for the treatment of myasthenia gravis. Autoimmunity 2010; 43:628-39. [DOI: 10.3109/08916931003599070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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337
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Extracorporeal immunoglobulin elimination for the treatment of severe myasthenia gravis. J Biomed Biotechnol 2010; 2010:419520. [PMID: 20300435 PMCID: PMC2840412 DOI: 10.1155/2010/419520] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Accepted: 01/17/2010] [Indexed: 12/16/2022] Open
Abstract
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.
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338
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Kim WH, Kim JH, Kim EK, Yun SP, Kim KK, Kim WC, Jeong HC. Myasthenia gravis presenting as isolated respiratory failure: a case report. Korean J Intern Med 2010; 25:101-4. [PMID: 20195411 PMCID: PMC2829406 DOI: 10.3904/kjim.2010.25.1.101] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Accepted: 09/21/2007] [Indexed: 01/03/2023] Open
Abstract
Myasthenia gravis (MG) is often complicated by respiratory failure, known as a myasthenic crisis. However, most of the patients who develop respiratory symptoms do so during the late course of disease and have other neurological signs and symptoms. However, in some patients respiratory failure is the initial presenting symptom. We report the case of a 68-year-old woman with MG who presented with isolated respiratory failure as her first presenting symptom. As illustrated by this case, it is important to consider neuromuscular disorders in cases of unexplained respiratory failure.
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Affiliation(s)
- Won Hee Kim
- Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, Korea
| | - Jung Hyun Kim
- Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, Korea
| | - Eun Kyung Kim
- Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, Korea
| | - Sang Pil Yun
- Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, Korea
| | - Kyung Keun Kim
- Department of Neurology, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, Korea
| | - Won Chan Kim
- Department of Neurology, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, Korea
| | - Hye Cheol Jeong
- Division of Respiratory and Critical Care Medicine, Department of Internal Medicine, CHA Bundang Medical Center, CHA University School of Medicine, Seongnam, Korea
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339
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Karussis D, Teitelbaum D, Sicsic C, Brenner T. Long-term treatment of multiple sclerosis with glatiramer acetate: Natural history of the subtypes of anti-glatiramer acetate antibodies and their correlation with clinical efficacy. J Neuroimmunol 2010; 220:125-30. [DOI: 10.1016/j.jneuroim.2010.01.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2009] [Revised: 12/15/2009] [Accepted: 01/15/2010] [Indexed: 10/19/2022]
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340
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Mujer de 19 años con ptosis palpebral y debilidad muscular fluctuante. A propósito de un caso de miastenia gravis. Semergen 2010. [DOI: 10.1016/j.semerg.2009.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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341
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Zuckerman NS, Howard WA, Bismuth J, Gibson K, Edelman H, Berrih-Aknin S, Dunn-Walters D, Mehr R. Ectopic GC in the thymus of myasthenia gravis patients show characteristics of normal GC. Eur J Immunol 2010; 40:1150-61. [DOI: 10.1002/eji.200939914] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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342
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Mizrachi K, Aricha R, Feferman T, Kela-Madar N, Mandel I, Paperna T, Miller A, Ben-Nun A, Berrih-Aknin S, Souroujon MC, Fuchs S. Involvement of phosphodiesterases in autoimmune diseases. J Neuroimmunol 2010; 220:43-51. [PMID: 20100627 DOI: 10.1016/j.jneuroim.2009.12.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2009] [Revised: 12/28/2009] [Accepted: 12/28/2009] [Indexed: 12/16/2022]
Abstract
We have previously shown that several phosphodiesterase (PDE) subtypes are up-regulated in muscles and lymph node cells (LNC) of rats with experimental autoimmune myasthenia gravis (EAMG). In the present study we investigated PDE expression during the course of EAMG and experimental allergic encephalomyelitis (EAE) and found that the up-regulated expression of selected PDE subtypes in both experimental models is correlated with disease severity. In EAMG, PDE expression is correlated also with muscle damage. A similar up-regulation of PDE was also observed in the respective human diseases, MG and multiple sclerosis (MS). Our findings suggest that change in PDE expression levels is a general phenomenon in autoimmune diseases and may also be used as a marker for disease severity.
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Affiliation(s)
- Keren Mizrachi
- Department of Immunology, Weizmann Institute of Science, Rehovot, Israel
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343
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Liu R, Hao J, Dayao CS, Shi FD, Campagnolo DI. T-bet deficiency decreases susceptibility to experimental myasthenia gravis. Exp Neurol 2009; 220:366-73. [DOI: 10.1016/j.expneurol.2009.09.022] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Revised: 09/21/2009] [Accepted: 09/23/2009] [Indexed: 01/06/2023]
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344
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Malik UF, Martin MR, Pham HD, Mahmoud A, Kapre S. Intermittent weakness and mediastinal weakening. Mcgill J Med 2009; 12:18. [PMID: 21152329 PMCID: PMC2997250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Affiliation(s)
- Umer Feroze Malik
- To whom correspondence should be addressed:
Umer Feroze Malik, MD
P.O Box 1020
San Joaquin General Hospital
500 West Hospital Road
French Camp, Ca
95231
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345
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Abstract
Current therapy for myasthenia gravis is directed towards generalized modulation and suppression of the immune system. These approaches have been extensively studied and are effective in many patients with myasthenia, but at the cost of significant adverse effects due to the global effects on the immune system. Future directions in therapy are geared towards focused immunotherapies that aim to improve outcomes while lessening the burden of side effects. This paper reviews both the current accepted treatments for myasthenia gravis as well as promising targeted therapies in development.
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Affiliation(s)
- Hans D Katzberg
- Department of Neurology, Stanford University, Palo Alto, CA, USA
| | - Vera Bril
- University Health Network, University of Toronto, Toronto, Canada
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346
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Leonardi M, Raggi A, Antozzi C, Confalonieri P, Maggi L, Cornelio F, Mantegazza R. Identification of international classification of functioning, disability and health relevant categories to describe functioning and disability of patients with myasthenia gravis. Disabil Rehabil 2009; 31:2041-6. [DOI: 10.3109/09638280902893634] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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347
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Concordance between severity of disease, disability and health-related quality of life in Myasthenia gravis. Neurol Sci 2009; 31:41-5. [DOI: 10.1007/s10072-009-0167-y] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2008] [Accepted: 09/29/2009] [Indexed: 01/06/2023]
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348
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Zhou Y, Cheng G, Dieter L, Hjalt TA, Andrade FH, Stahl JS, Kaminski HJ. An altered phenotype in a conditional knockout of Pitx2 in extraocular muscle. Invest Ophthalmol Vis Sci 2009; 50:4531-41. [PMID: 19407022 PMCID: PMC4330467 DOI: 10.1167/iovs.08-2950] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
PURPOSE To determine the temporal and spatial expression of Pitx2, a bicoid-like homeobox transcription factor, during postnatal development of mouse extraocular muscle and to evaluate its role in the growth and phenotypic maintenance of postnatal extraocular muscle. METHODS Mouse extraocular muscles of different ages were examined for the expression of Pitx2 by RT-PCR, q-PCR, and immunostaining. A conditional mutant mouse strain, in which Pitx2 function is inactivated at postnatal day (P)0, was generated with a Cre-loxP strategy. Histology, immunostaining, real-time PCR, in vitro muscle contractility, and in vivo ocular motility were used to study the effect of Pitx2 depletion on extraocular muscle. RESULTS All three Pitx2 isoforms were expressed by extraocular muscle and at higher levels than in other striated muscles. Immunostaining demonstrated the presence of Pitx2 mainly in extraocular muscle myonuclei. However, no obvious expression patterns were observed in terms of anatomic region (orbital versus global layer), innervation zone, or muscle fiber types. The mutant extraocular muscle had no obvious pathology but had altered muscle fiber sizes. Expression levels of myosin isoforms Myh1, Myh6, Myh7, and Myh13 were reduced, whereas Myh2, Myh3, Myh4, and Myh8 were not affected by postnatal loss of Pitx2. In vitro, Pitx2 loss made the extraocular muscles stronger, faster, and more fatigable. Eye movement recordings found saccades to have a lower peak velocity. CONCLUSIONS Pitx2 is important in maintaining the mature extraocular muscle phenotype and regulating the expression of critical contractile proteins. Modulation of Pitx2 expression can influence extraocular muscle function with long-term therapeutic implications.
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Affiliation(s)
- Yuefang Zhou
- Department of Neurology and Psychiatry, Saint Louis University, St. Louis, Missouri
| | - Georgiana Cheng
- Department of Pathobiology, Cleveland Clinic, Cleveland, Ohio
| | - Lisa Dieter
- Department of Neurology and Psychiatry, Saint Louis University, St. Louis, Missouri
| | - Tord A. Hjalt
- Department of Experimental Medical Research, Lund University, Lund, Sweden
| | | | - John S. Stahl
- Louis Stokes Cleveland VA Medical Center, Cleveland, Ohio
- Department of Neurology, Case Western Reserve University, Cleveland, Ohio
| | - Henry J. Kaminski
- Department of Neurology and Psychiatry, Saint Louis University, St. Louis, Missouri
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349
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Sheng JR, Li LC, Prabhakar BS, Meriggioli MN. Acetylcholine receptor-alpha subunit expression in myasthenia gravis: a role for the autoantigen in pathogenesis? Muscle Nerve 2009; 40:279-86. [PMID: 19609914 DOI: 10.1002/mus.21371] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Previous studies have shown increased expression of acetylcholine receptor-alpha (AChR-alpha) subunit transcripts in myasthenia gravis (MG) and experimental MG (EAMG), but none examined the functional properties of this overexpression. In this study we examined the mRNA and protein expression of AChR-alpha as well as the pattern of alpha-bungarotoxin labeling in muscle tissue from EAMG mice with varying disease severity. AChR-alpha expression was increased considerably in endplates from mice with severe EAMG, but it was distinct and greatly in excess of alpha-bungarotoxin labeling. This "aberrant expression" occurred in mice with morphologic endplate damage, and the pattern of complement and immunoglobulin deposition in muscle from these mice appeared to mirror the pattern of AChR-alpha expression. The loss of functional AChR in severe MG increases transcription of AChR-alpha mRNA, but the expressed protein is "functionally inert," failing to compensate for loss of AChR. This enhanced expression of AChR may play a role in driving the ongoing autoimmune response. Muscle Nerve 40: 279-286, 2009.
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Affiliation(s)
- Jian Rong Sheng
- Division of Neuromuscular Diseases, Department of Neurology and Rehabilitation, 912 South Wood Street, M/C 796, University of Illinois at Chicago, Chicago, Illinois 60612, USA
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350
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Luo J, Lindstrom J. Antigenic structure of the human muscle nicotinic acetylcholine receptor main immunogenic region. J Mol Neurosci 2009; 40:217-20. [PMID: 19705087 DOI: 10.1007/s12031-009-9271-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2009] [Accepted: 07/22/2009] [Indexed: 10/20/2022]
Abstract
The main immunogenic region on the alpha1 subunits of muscle nicotinic acetylcholine receptors provokes half or more of the autoantibodies in myasthenia gravis and its animal model. Many of these autoantibodies depend on the native conformation of the receptor for their ability to bind with high affinity. We mapped this region and explained the conformation dependence of its epitopes by making chimeras in which sequences of human muscle alpha1 subunits were replaced in human neuronal alpha7 subunits or Aplysia acetylcholine binding protein. These chimeras also revealed that the main immunogenic region can play a major role in promoting conformational maturation and, consequently, assembly of receptor subunits.
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Affiliation(s)
- Jie Luo
- Department of Neuroscience, Medical School of the University of Pennsylvania, Philadelphia, PA 19104-6074, USA.
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