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Bokoliya S, Patil S, Nagappa M, Taly A. A Simple, Rapid and Non-Radiolabeled Immune Assay to Detect Anti-AChR Antibodies in Myasthenia Gravis. Lab Med 2019; 50:229-235. [PMID: 30535084 DOI: 10.1093/labmed/lmy038] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE To assess the practicality of dot-blot testing for rapid and sensitive detection of the antiacetylcholine receptor (anti-AChR) antibodies in myasthenia gravis (MG). METHODS In this case-control study, we tested serum specimens of 85 patients with MG, 85 healthy control individuals, and 85 patients without MG who have other autoimmune and neurological illnesses. All the serum specimens were tested for anti-AChR antibodies using 3 assays: in-house enzyme-linked immunosorbent assay (ELISA), the dot-blot assay, and commercial ELISA. RESULTS In-house ELISA, commercial ELISA, and dot-blot test results were positive for anti-AChR antibodies in 65 (76.5%) patients with MG. The results of all 3 tests were negative for anti-AChR antibodies in healthy controls and patients without MG. We observed perfect concordance (K = 1, P <.001) between all 3 tests. In-house ELISA correlated significantly (r = 0.873, P <.001) with commercial ELISA. In-house ELISA and the dot-blot test demonstrated similar diagnostic performance in detecting anti-AChR antibodies. CONCLUSIONS The dot-blot assay is a simple, nonradioactive immune assay for rapid detection of anti-AChR antibodies in MG.
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Affiliation(s)
- Suresh Bokoliya
- Department of Neuromicrobiology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India
| | - Shripad Patil
- Department of Neuromicrobiology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India
| | - Madhu Nagappa
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India
| | - Arun Taly
- Department of Neurology, National Institute of Mental Health and Neurosciences (NIMHANS), Bangalore, India
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2
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Abstract
The diagnostic use of antibodies is dependent on sensitivity and specificity of the methods of antibody detection, which have been developed and improved over the years. Here, we review the different methods for the detection of acetylcholine receptor and muscle-specific kinase antibodies, which are, so far, the only antibodies recognised as pathogenic in myasthenia gravis (MG). Seronegative MG patients will benefit from more sensitive methods of antibody detection. The most recent developments in antibody detection assays, particularly those based on cells expressing target antigens, allow rapid and reliable identification of autoantibodies, improving the diagnosis and treatment of MG patients. The same approaches to antibody detection are now being applied to a wide range of other autoantigens and other autoimmune diseases.
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Affiliation(s)
- M Isabel Leite
- Department of Clinical Neurology, John Radcliffe Hospital, University of Oxford, West Wing OX3 9DS, UK
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3
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Suhail H, Subbiah V, Singh S, Behari M. Serological and clinical features of patients with myasthenia gravis in north Indian population. Int J Neurosci 2010; 120:115-9. [PMID: 20199203 DOI: 10.3109/00207450903389131] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Myasthenia gravis (MG) is a disorder of neuromuscular junction associated with presence of antibodies against nicotinic acetylcholine receptors (nAChRs). Here, we compared the clinical and serological profile of seropositive myasthenia gravis (SPMG) and seronegative myasthenia gravis (SNMG) patients. Anti-AChR antibody was measured using radio receptor immunoassay and correlated with clinical phenotype in 250 MG patients over 2004 and 2006. Out of 250 MG patients, 161 (64.4%) were males (male:female = 1.8:1). SNMG patients formed 40% (n = 101) of our MG patients which is much higher as compared to Caucasian and Oriental population (15%-20%). The median age of disease onset in SPMG was significantly higher than SNMG patients (43 years; range 8-74 vs. 35 years; range 4-72, p = .022). A bimodal peak of age of disease onset in both genders was observed (first peak in second-third decades and second one in fifth-sixth decades). Among the MG patients with late-onset of disease, male were significantly higher compared to Caucasian and Oriental MG population (p = .047). MG patients with thymoma were significantly older and consisted of higher percent of males. Bulbar symptoms and severe grade (IIB+ III+ IV) at disease onset were more frequent in SPMG than SNMG patients.
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Affiliation(s)
- Hamid Suhail
- Department of Neurology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
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4
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Cole RN, Reddel SW, Gervásio OL, Phillips WD. Anti-MuSK patient antibodies disrupt the mouse neuromuscular junction. Ann Neurol 2008; 63:782-9. [DOI: 10.1002/ana.21371] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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5
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Vincent A. Autoantibodies in different forms of myasthenia gravis and in the Lambert-Eaton syndrome. HANDBOOK OF CLINICAL NEUROLOGY 2008; 91:213-227. [PMID: 18631844 DOI: 10.1016/s0072-9752(07)01506-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Affiliation(s)
- Angela Vincent
- Department of Clinical Neurology, University of Oxford, Oxford, UK.
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6
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Zhou L, McConville J, Chaudhry V, Adams RN, Skolasky RL, Vincent A, Drachman DB. Clinical comparison of muscle-specific tyrosine kinase (MuSK) antibody-positive and -negative myasthenic patients. Muscle Nerve 2004; 30:55-60. [PMID: 15221879 DOI: 10.1002/mus.20069] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We assayed cryopreserved sera from 38 acetylcholine receptor (AChR) antibody-negative patients with myasthenia gravis (MG) who were followed clinically for muscle-specific tyrosine kinase (MuSK) antibodies and analyzed and compared their clinical characteristics. None of 13 sera from patients with purely ocular MG were positive. Sera from 10 of 25 patients (40%) with generalized MG were positive for MuSK antibodies. The age at onset of myasthenic symptoms was significantly earlier in MuSK antibody-positive patients (P = 0.02). MuSK antibodies were present in AChR antibody-negative patients of either gender, with virtually identical prevalence in women (41.2%) and men (37.5%). The distribution of weakness more commonly involved neck muscles in MuSK antibody-positive patients, and limb muscles in MuSK antibody-negative patients. Patients responded to immunosuppressive treatment regardless of whether MuSK antibody was present. We conclude that MuSK antibodies are present and diagnostically useful in a subset of myasthenic patients without AChR antibodies. Although the distribution of weakness differs somewhat depending on whether MuSK antibodies are present, responses to anticholinesterase and immunosuppressive treatments are similar.
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Affiliation(s)
- Lan Zhou
- Neuromuscular Unit, Department of Neurology, Johns Hopkins School of Medicine, Meyer Building 5-119, 600 North Wolfe Street, Baltimore, Maryland 21287-7519, USA
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7
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Affiliation(s)
- Daniel B Drachman
- Department of Neurology and Neuroscience, Johns Hopkins School of Medicine, Baltimore, Maryland 21287, USA.
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8
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Seronegative generalised myasthenia gravis: clinical features, antibodies, and their targets. Lancet Neurol 2003; 2:99-106. [PMID: 12849266 DOI: 10.1016/s1474-4422(03)00306-5] [Citation(s) in RCA: 166] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Myasthenia gravis (MG) is a well-recognised disorder of neuromuscular transmission that can be diagnosed by the presence of antibodies to the acetylcholine receptor (AChR). However, some patients (about 15%) with generalised MG do not have detectable AChR antibodies. There is some evidence, however, that this "seronegative" MG is an antibody-mediated disorder. Plasma from patients with the disorder seems to contain various distinct humoral factors: IgG antibodies that reversibly inhibit AChR function; a non-IgG (possibly IgM) factor that indirectly inhibits AChR function; and an IgG antibody against the muscle-specific kinase (MuSK). The presence of antibodies against MuSK appears to define a subgroup of patients with seronegative MG who have predominantly localised, in many cases bulbar, muscle weaknesses (face, tongue, pharynx, etc) and reduced response to conventional immunosuppressive treatments. Moreover, muscle wasting may be present, which prevents complete response to these therapies.
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9
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Hoch W, McConville J, Helms S, Newsom-Davis J, Melms A, Vincent A. Auto-antibodies to the receptor tyrosine kinase MuSK in patients with myasthenia gravis without acetylcholine receptor antibodies. Nat Med 2001; 7:365-8. [PMID: 11231638 DOI: 10.1038/85520] [Citation(s) in RCA: 729] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Myasthenia gravis (MG) is an antibody-mediated autoimmune disease of the neuromuscular junction. In approximately 80% of patients, auto-antibodies to the muscle nicotinic acetylcholine receptor (AChR) are present. These antibodies cause loss of AChR numbers and function, and lead to failure of neuromuscular transmission with muscle weakness. The pathogenic mechanisms acting in the 20% of patients with generalized MG who are seronegative for AChR-antibodies (AChR-Ab) have not been elucidated, but there is evidence that they also have an antibody-mediated disorder, with the antibodies directed towards another, previously unidentified muscle-surface-membrane target. Here we show that 70% of AChR-Ab-seronegative MG patients, but not AChR-Ab-seropositive MG patients, have serum auto-antibodies against the muscle-specific receptor tyrosine kinase, MuSK. MuSK mediates the agrin-induced clustering of AChRs during synapse formation, and is also expressed at the mature neuromuscular junction. The MuSK antibodies were specific for the extracellular domains of MuSK expressed in transfected COS7 cells and strongly inhibited MuSK function in cultured myotubes. Our results indicate the involvement of MuSK antibodies in the pathogenesis of AChR-Ab-seronegative MG, thus defining two immunologically distinct forms of the disease. Measurement of MuSK antibodies will substantially aid diagnosis and clinical management.
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Affiliation(s)
- W Hoch
- Max Planck Institute for Developmental Biology, Tübingen, Germany
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Blaes F, Beeson D, Plested P, Lang B, Vincent A. IgG from ?seronegative? myasthenia gravis patients binds to a muscle cell line, TE671, but not to human acetylcholine receptor. Ann Neurol 2001. [DOI: 10.1002/1531-8249(200004)47:4<504::aid-ana14>3.0.co;2-q] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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11
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Tesar V, Jelínková E, Jirsa M, Bakosová M, Pitha P, Chábová V. Soluble adhesion molecules and cytokines in patients with myasthenia gravis treated by plasma exchange. Blood Purif 2000; 18:115-20. [PMID: 10838470 DOI: 10.1159/000014434] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Plasma exchange (PE) is an effective therapeutic method used in patients with myasthenia gravis (MG) refractory to common therapy and/or with life-threatening respiratory complications. Except for acetylcholine receptor antibodies (AChRAbs), some other inflammatory mediators possibly activated in MG may also be removed during PE. Serum levels of soluble adhesion molecules (sICAM-1 and sVCAM-1), IL-6 and soluble receptors for IL-2 (sIL-2R), IL-6 (sIL-6R) and TNF alpha (sTNF-R II) were measured in 20 MG patients assigned to treatment with PE. On the basis of the serum levels of AChRAb the patients were subdivided into 2 groups (8 patients with low AChRAb, 12 patients with high AChRAb). Soluble adhesion molecules and cytokines were measured before the first and last PE, at the end of the first PE and in the samples of plasma filtrate obtained during the first PE. Before the first PE patients with MG had higher serum levels of sICAM-1, sVCAM-1, sIL-2R and sTNF-R II than controls. Both after the first PE and during the course of PE, a substantial decrease in serum levels of AChRAb, sICAM-1 and sVCAM-1 was recorded. However, serum levels of sIL-2R and sTNF-R II were not significantly influenced by either a single treatment or during the course of PE. There were high levels of AChRAb, soluble adhesion molecules and soluble cytokine receptors in plasma filtrates too. Patients with high circulating AChRAb had higher serum levels of sICAM-1 and sVCAM-1 than patients with low AChRAb. Increased serum levels of soluble adhesion molecules and soluble cytokine receptors in patients with MG suggest some systemic activation of the immune response which is more pronounced in patients with high circulating AChRAb. PE led to the decrease in serum AChRAb and soluble adhesion molecules due to their effective filtration but, on the other hand, serum levels of soluble cytokine receptors were not influenced by PE, in spite of their effective filtration which is probably counteracted by their increased production, possibly stimulated by the contact of the blood with the synthetic membrane.
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Affiliation(s)
- V Tesar
- 1st Department of Medicine, 1st School of Medicine, Charles University, Prague, Czech Republic
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12
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Qureshi AI, Suri MF. Plasma exchange for treatment of myasthenia gravis: pathophysiologic basis and clinical experience. THERAPEUTIC APHERESIS : OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY FOR APHERESIS AND THE JAPANESE SOCIETY FOR APHERESIS 2000; 4:280-6. [PMID: 10975474 DOI: 10.1046/j.1526-0968.2000.004004280.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Myasthenia gravis is an autoimmune disease characterized by production of antibodies to acetylcholine receptors located at the motor end plate in skeletal muscles. The antibodies bind and subsequently induce degeneration of these receptors. Loss of acetylcholine receptors results in inadequate contraction of muscle fibers in response to acetylcholine released from nerve terminals and clinically apparent muscle weakness. Plasma exchange removes the circulating antibodies in myasthenic patients with short-term clinical improvement. Plasma exchange may be indicated in patients with acute exacerbation of neuromuscular weakness with bulbar or respiratory compromise, preoperative optimization prior to thymectomy, and postoperative deterioration following thymectomy or other surgical procedures. Long-term, intermittent plasma exchange for patients who do not adequately respond to standard treatment is another evolving indication.
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Affiliation(s)
- A I Qureshi
- Department of Neurosurgery, School of Biomedical Sciences and Medicine, State University of New York, Buffalo, USA.
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Sharshar T, Lacroix-Desmazes S, Mouthon L, Kaveri S, Gajdos P, Kazatchkine MD. Selective impairment of serum antibody repertoires toward muscle and thymus antigens in patients with seronegative and seropositive myasthenia gravis. Eur J Immunol 1998; 28:2344-54. [PMID: 9710212 DOI: 10.1002/(sici)1521-4141(199808)28:08<2344::aid-immu2344>3.0.co;2-t] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
We analyzed the antibody (Ab) repertoires of IgM and IgG of patients with seropositive and patients with seronegative myasthenia gravis (MG) toward self antigens by means of a quantitative immunoblotting technique using normal human tissue extracts as sources of self antigens. Repertoires of reactivities of IgG and IgM with liver, kidney and stomach antigens were conserved between myasthenic patients and controls. IgG and IgM Ab repertoires toward muscle antigens differed significantly between patients with seropositive MG and healthy donors, as assessed by multiparametric statistical analysis. Patterns of Ab reactivities to muscle antigens were similar in patients with seronegative MG and healthy controls. Antibody repertoires of IgG and IgM toward thymus antigens of both seropositive and seronegative MG patients, differed significantly from those of healthy individuals. Our results indicate that MG is characterized by a selective impairment of self-reactive Ab repertoires toward muscle and thymus antigens. The observation that self-reactive Ab repertoires toward thymus antigens are similar in patients with seropositive and seronegative MG suggests that both forms of MG share common immunopathological features.
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Affiliation(s)
- T Sharshar
- INSERM U430 and Université Pierre et Marie Curie, Hôpital Broussais, Paris, France
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14
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Abstract
Adult-onset myasthenia gravis is an acquired autoimmune disorder of neuromuscular transmission in which acetylcholine receptor antibodies attack the postsynaptic membrane of the neuromuscular junction. Although the cause of this disease is unknown, the role of immune responses in its pathogenesis is well established. Circulating acetylcholine receptor antibodies are present in 80% to 90% of patients with the generalized form of myasthenia gravis. Most patients have ptosis, diplopia, dysarthria and dysphagia. The weakness and fatigue worsen on exertion and improve with rest. Respiratory muscle and limb weakness are rare at the onset of the disease. For the past two decades, there has been considerable progress in understanding the diagnosis and management of myasthenia gravis. The diagnosis is based on clinical presentation, neurologic examination, and confirmation by means of electrophysiologic testing and immunologic studies. Myasthenia gravis mimics many neuromuscular diseases and even illnesses such as depression and chronic fatigue syndrome. One should always exclude drug-induced myasthenia gravis for all patients. With the introduction of new modalities of treatment, particularly immunosuppressive or immunomodulating drugs, plasma exchange and thymectomy, the morbidity and mortality of myasthenia gravis have decreased dramatically to the point that myasthenia gravis should not be considered as serious a disease as it once was. Although the several therapeutic options are usually effective and have meant independence in daily life to many patients with myasthenia gravis, well-designed, controlled, prospective studies are still lacking.
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Affiliation(s)
- R Pourmand
- Department of Neurology, Indiana University School of Medicine, Indianapolis, USA
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Gu D, Wogensen L, Calcutt NA, Xia C, Zhu S, Merlie JP, Fox HS, Lindstrom J, Powell HC, Sarvetnick N. Myasthenia gravis-like syndrome induced by expression of interferon gamma in the neuromuscular junction. J Exp Med 1995; 181:547-57. [PMID: 7836911 PMCID: PMC2191877 DOI: 10.1084/jem.181.2.547] [Citation(s) in RCA: 111] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Abnormal humoral responses toward motor end plate constituents in muscle induce myasthenia gravis (MG). To study the etiology of this disease, and whether it could be induced by host defense molecules, we examined the consequences of interferon (IFN) gamma production within the neuromuscular junction of transgenic mice. The transgenic mice exhibited gradually increasing muscular weakness, flaccid paralysis, and functional disruption of the neuromuscular junction that was reversed after administration of an inhibitor of acetylcholinesterase, features which are strikingly similar to human MG. Furthermore, histological examination revealed infiltration of mononuclear cells and autoantibody deposition at motor end plates. Immunoprecipitation analysis indicated that a previously unidentified 87-kD target antigen was recognized by sera from transgenic mice and also by sera from the majority of human MG patients studied. These results suggest that expression of IFN-gamma at motor end plates provokes an autoimmune humoral response, similar to human MG, thus linking the expression of this factor with development of this disease.
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Affiliation(s)
- D Gu
- Department of Neuropharmacology, Scripps Research Institute, La Jolla, California
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Abstract
Ocular myasthenia is a localized form of myasthenia clinically involving only the extraocular, levator palpebrae superioris, and/or orbicularis oculi muscles. Ocular manifestations can masquerade as a variety of ocular motility disorders, including cranial nerve and gaze palsies. A history of variable and fatiguable muscle weakness suggests this diagnosis, which may be confirmed by the edrophonium (Tensilon) test and acetylcholine receptor antibody titer. Anticholinesterases, corticosteroids and other immunosuppressive agents, and other therapeutic modalities, including thymectomy and plasmapheresis, are used in treatment. As the pathophysiology of myasthenia has been elucidated in recent years, newer treatment strategies have evolved, resulting in a much more favorable prognosis than several decades ago. This review provides historical background, pathophysiology, immuno-genetics, diagnostic testing, and treatment options for ocular myasthenia, as well as a discussion of drug-induced myasthenic syndromes.
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Affiliation(s)
- D A Weinberg
- Neuro-Ophthalmology Service, Wills Eye Hospital, Philadelphia, Pennsylvania
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Affiliation(s)
- D B Drachman
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287-7519
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Wilcox MS, Bilbao A. Sensitivity of electrophysiological studies and the carpal tunnel syndrome. Muscle Nerve 1993; 16:1265-6. [PMID: 8413381 DOI: 10.1002/mus.880161119] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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Vincent A, Li Z, Hart A, Barrett-Jolley R, Yamamoto T, Burges J, Wray D, Byrne N, Molenaar P, Newsom-Davis J. Seronegative myasthenia gravis. Evidence for plasma factor(s) interfering with acetylcholine receptor function. Ann N Y Acad Sci 1993; 681:529-38. [PMID: 8395163 DOI: 10.1111/j.1749-6632.1993.tb22936.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- A Vincent
- Department of Clinical Neurology, University of Oxford, United Kingdom
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