Giant cell myositis and myocarditis revisited

Giant cell myositis (GCMm) and giant cell myocarditis (GCMc) are two rare autoimmune conditions. Among these, GCMc is a life-threatening disease with a 1-year mortality rate of 70%. Lethal ventricular arrhythmias, rapid evolution to heart failure and sudden death risk makes GCMc an emergency condition. It is thought to be mediated by T-cells and characterized by the presence of myofiber necrosis and giant cells in biopsies. Most commonly co-manifesting conditions with GCMm and/or GCMc are thymoma, myasthenia gravis and orbital myositis, all of which are treatable. As suspicion is the key approach in diagnosis, the physician following patients with thymoma with or without myasthenia gravis and with orbital myositis should always be alert. The fatal nature of GCMc associated with these relatively benign diseases deserves a special emergency attention with prompt institution of combined immunosuppressive treatment and very early inclusion of heart failure teams.Key words: giant cell myositis, giant cell myocarditis, thymoma/myasthenia gravis, orbital myositis     

Association of polymyositis, myasthenia, and thymoma. A case and review of the literature

We report the case of a 51 years old woman with myositis, myasthenia gravis and thymoma. First apparent sign is myositis in 1976 but chest X ray show a mediastinal opacity and the patient reports an intermittent diplopia since 1973. The evolution of myositis occurs in two bouts in 1976 and 1981, Myasthenia gravis restricted to diplopia from 1973 to 1979 grow worse first alone then in association with increase of myositis signs in 1981. The mediastinal opacity seen on chest X ray in 1976 don't change and is revealed to be a thymoma at operation in 1981. After thymoma ablation myasthenic and myositis signs decrease. This pathologic association is found 24 times in literature and involves "giant cells" in muscle biopsy in about 50 p. 100 of cases and a myocarditis also with "giant cells". Those "giant cells" unusual in common myositis appears to have a prognostic value.     

The co-existence of myasthenia gravis in patients with myositis: A case series

ObjectiveMyositis and myasthenia gravis (MG) are both autoimmune disorders presenting with muscle weakness. Rarely, they occur simultaneously in the same patient. Since the management of myasthenia gravis differs from that of myositis, it is important to recognize when patients have both diseases. We reviewed the cases of 6 patients with both myositis and MG to identify clinical features that suggest the possibility of co-existing MG in myositis patients.MethodsWe identified 6 patients with dermatomyositis or polymyositis and MG. We reviewed their medical records to assess their clinical presentations, laboratory findings, and electrophysiological features.ResultsAll 6 patients had definite dermatomyositis or polymyositis by the criteria of Bohan and Peter as well as electrophysiologic and/or serologic confirmation of MG. Among overlap patients, 5/6 (83%) had bulbar weakness, 2/6 (33%) had ptosis, and 1/6 (17%) had diplopia. Fatigable weakness was noted by 5/6 (83%) patients. Treatment with pyridostigmine improved symptoms in 5/6 (83%) patients. High-dose steroids were associated with worsening weakness in 2/6 (33%) patients.ConclusionsProminent bulbar symptoms, ptosis, diplopia, and fatigable weakness should suggest the possibility of MG in patients with myositis. A suspicion of MG may be confirmed through appropriate electrophysiologic and laboratory testing. In those with myositis–MG overlap, high-dose steroids may exacerbate symptoms and pyridostigmine may play an important therapeutic role.     

The co-existence of myasthenia gravis in patients with myositis: A case series

Objective

Myositis and myasthenia gravis (MG) are both autoimmune disorders presenting with muscle weakness. Rarely, they occur simultaneously in the same patient. Since the management of myasthenia gravis differs from that of myositis, it is important to recognize when patients have both diseases. We reviewed the cases of 6 patients with both myositis and MG to identify clinical features that suggest the possibility of co-existing MG in myositis patients.

Methods

We identified 6 patients with dermatomyositis or polymyositis and MG. We reviewed their medical records to assess their clinical presentations, laboratory findings, and electrophysiological features.

Results

All 6 patients had definite dermatomyositis or polymyositis by the criteria of Bohan and Peter as well as electrophysiologic and/or serologic confirmation of MG. Among overlap patients, 5/6 (83%) had bulbar weakness, 2/6 (33%) had ptosis, and 1/6 (17%) had diplopia. Fatigable weakness was noted by 5/6 (83%) patients. Treatment with pyridostigmine improved symptoms in 5/6 (83%) patients. High-dose steroids were associated with worsening weakness in 2/6 (33%) patients.

Conclusions

Prominent bulbar symptoms, ptosis, diplopia, and fatigable weakness should suggest the possibility of MG in patients with myositis. A suspicion of MG may be confirmed through appropriate electrophysiologic and laboratory testing. In those with myositis–MG overlap, high-dose steroids may exacerbate symptoms and pyridostigmine may play an important therapeutic role.     

Intractable ventricular tachycardia in a patient with giant cell myocarditis, thymoma and myasthenia gravis

A 48-year-old man presented with a malignant thymoma in combination with myositis, myasthenia gravis, a giant cell myocarditis and recurrent intractable ventricular tachycardias. Despite various therapies (chemical, electrical and surgical), arrhythmias supervened in the presence of a normal coronary arteriogram. Active myocarditis was believed to be the mechanism of the ventricular tachycardias.     

Respiratory failure due to vocal cord paresis in myasthenia gravis

This report describes a female patient with myasthenia gravis who developed respiratory failure due to vocal cord paresis. The diagnosis was delayed due to the absence of other myasthenic symptoms (e.g. ptosis, muscle weakness and dysphagia). On direct laryngoscopy, her vocal cords were seen to be in the paramedian position and to move apart after the intravenous injection of edrophonium. The patient initially presented with ocular myasthenia and later returned with isolated respiratory failure. A review of the pertinent literature revealed few reports on myasthenia gravis presenting in this manner.     

Sarcoid myositis with muscle weakness as a presenting symptom

A 54-year-old woman complaining of muscle weakness and weight loss was admitted to our hospital with suspected polymyositis. Muscle biopsy revealed Langhans-type giant cells and noncaseating granulomas. Therefore, sarcoid myositis was diagnosed. The patient was treated with prednisolone, and the symptoms improved gradually. Generally, sarcoidosis is identified clinically in patients with foggy vision or mediastinal lymphadenopathy, but muscular weakness may be an infrequently observed initial symptom. Sarcoidosis should be considered in the differential diagnosis of polymyositis.     

A case of sarcoidosis developing as sarcoid myopathy concomitant with systemic sclerosis and review of the literature

Abstract

A 65-year-old man was diagnosed with systemic sclerosis on the basis of skin thickening and positivity of anti-Scl-70 antibodies. Because myogenic enzymes, such as creatinine phosphokinase and aldorase, were also elevated, myopathy or myositis associated with systemic sclerosis was considered. Muscle magnetic resonance imaging and gallium scintigraphy did not show abnormalities. Findings of muscle biopsy demonstrated presence of noncaseating granulomas with multinucleated giant cells. In addition, serum angiotensin-converting enzyme and lysozyme were elevated, and therefore a diagnosis of sarcoid myopathy was made. Further, renal sarcoidosis was revealed with renal biopsy. Prednisolone (40 mg/day) improved both the myopathy and nephritis. Sarcoid myopathy is a rare condition, but it should be considered when myogenic enzymes are elevated in the patient with systemic sclerosis. Further, muscle biopsy may be essential to make an accurate diagnosis in such condition.     

Adult celiac disease with acetylcholine receptor antibody positive myasthenia gravis

Celiac disease has been associated with some autoimmune disorders. A 40-year-old competitive strongman with celiac disease responded to a glutenfree diet, but developed profound and generalized motor weakness with acetylcholine receptor antibody positive myasthenia gravis, a disorder reported to occur in about 1 in 5000. This possible relationship between myasthenia gravis and celiac disease was further explored in serological studies. Frozen stored serum samples from 23 acetylcholine receptor antibody positive myasthenia gravis patients with no intestinal symptoms were used to screen for celiac disease. Both endomysial and tissue transglutaminase antibodies were examined. One of 23 （or, about 4.3%） was positive for both IgA-endomysial and IgA tissue transglutaminase antibodies. Endoscopic studies subsequently showed duodenal mucosal scalloping and biopsies confirmed the histopathological changes of celiac disease. Celiac disease and myasthenia gravis may occur together more often than is currently appreciated. The presence of motor weakness in celiac disease may be a clue to occult myasthenia gravis, even in the absence of intestinal symptoms.     

Pancreatic Cancer in a Patient with Myasthenia Gravis

Myasthenia gravis has been associated with several diseasessuch as hyperthyroidism and malignancy (thymoma,lung carcinoma) but so far no reports have demonstrated arelationship between this disease and pancreatic disease.We report a 66-year-old man with myasthenia gravis diagnosedon the basis of clinical symptoms (eyelid ptosis),typical abnormalities on repetitive nerve-stimulation tests,and the presence of Ach-R antibodies in the serum. The responseto anticholinesterasic agents (pyridostigmine) wasgood, but after 1 year, he developed pancreatic cancer andmyasthenia gravis symptoms recurred. After surgery andchemotherapy, myasthenia gravis symptoms disappeared.Some months later, the patient had a recurrence of pancreaticcancer after relapse of myasthenia gravis.     

Modulation of acetylcholine receptor by antibody against the receptor

Antibody against acetylcholine receptor induces an increase in the rate of degradation of acetylcholine receptors on a mouse cell line (BC(3)H-1) and cultured rat skeletal muscle. The increased rate of degradation results in a lowered density of acetylcholine receptors on muscle membrane and a lowered sensitivity to iontophoretically applied acetylcholine. The modulation of acetylcholine receptor is energy, temperature, and time dependent and may be related to antigenic modulation found in other systems. Acetylcholine noise analysis demonstrates that antibody against acetylcholine receptor reduces the channel mean conductance and mean open time slightly.It is concluded that antibody binds to the acetylcholine receptor, impairs its function, and induces receptor degradation. This results in a lowered density of acetylcholine receptor and a lowered sensitivity to acetylcholine. Patients with myasthenia gravis have antibodies to their acetylcholine receptor in their serum. Antigenic modulation of receptor in the muscle of patients with myasthenia gravis could contribute to the observed decrease in amplitudes of miniature endplate potentials and in muscle acetylcholine sensitivity, and the symptoms of muscular weakness.     

Myasthenia gravis

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

Myasthenia gravis and hyperthyroidism: two cases

It is well known that hyperthyroidism occurs in approximately 2 to 17.5% of patients with myasthenia gravis. Hyperthyroidism may influence the clinical course of myasthenia gravis. We report the cases of two patients, a 53-year-old man and an 18-year-old woman, who had both severe myasthenia gravis and hyperthyroidism due to Graves' disease. Myasthenia gravis affected in particular facio-ocular areas with diffuse myopathy and signs of neuromuscular block on the electromyogram. In one patient, the diagnosis of thyroid disease was made three months before the diagnosis of myasthenia gravis while in the other, thyroid disease was recognized four months after myasthenia gravis. Myasthenia gravis worsened after the development of hyperthyroidism in the second patient. Both patients were given anti-cholinesterase drugs. One underwent thymectomy. Radioiodine used for the treatment of hyperthyroidism improved the symptoms of myasthenia gravis in the first patient. The association of myasthenia gravis and hyperthyroidism is more than a coincidence; our cases illustrate the difficult diagnosis and management of these diseases. Clinicians should look for myasthenia gravis in hyperthyroid patients and vice versa, especially when symptoms of myasthenia gravis or hyperthyroidism worsen.     

A case of sarcoidosis developing as sarcoid myopathy concomitant with systemic sclerosis and review of the literature

A 65-year-old man was diagnosed with systemic sclerosis on the basis of skin thickening and positivity of anti-Scl-70 antibodies. Because myogenic enzymes, such as creatinine phosphokinase and aldorase, were also elevated, myopathy or myositis associated with systemic sclerosis was considered. Muscle magnetic resonance imaging and gallium scintigraphy did not show abnormalities. Findings of muscle biopsy demonstrated presence of noncaseating granulomas with multinucleated giant cells. In addition, serum angiotensin-converting enzyme and lysozyme were elevated, and therefore a diagnosis of sarcoid myopathy was made. Further, renal sarcoidosis was revealed with renal biopsy. Prednisolone (40 mg/day) improved both the myopathy and nephritis. Sarcoid myopathy is a rare condition, but it should be considered when myogenic enzymes are elevated in the patient with systemic sclerosis. Further, muscle biopsy may be essential to make an accurate diagnosis in such condition.     

Newly diagnosed multiple sclerosis in a patient with ocular myasthenia gravis: A case report

Rationale:Patients with myasthenia gravis may also have comorbid autoimmune diseases. Since both myasthenia gravis and neuromyelitis optica spectrum disease are mediated by antibodies, they are likely to occur together. However, since multiple sclerosis is an autoimmune disease that is not mediated by a specific antibody, it has fewer immune mechanisms in common with myasthenia gravis than neuromyelitis optica spectrum disease. We encountered a case of newly developed multiple sclerosis in a patient with myasthenia gravis.Patient concerns:A 46-year-old man was diagnosed with ocular myasthenia gravis 6 years ago and had been taking pyridostigmine to control his symptoms.Diagnosis:The patient developed right optic neuritis, and multiple sclerosis was suspected based on the brain magnetic resonance imaging findings. However, the required diagnostic criteria were not met.Interventions:Disease-modifying therapy was not initiated, and clinical progression of the disease was monitored.Outcomes:One year after the onset of optic neuritis, the patient developed myelitis and was diagnosed with multiple sclerosis, prompting treatment with disease-modifying therapy.Lessons:When optic neuritis occurs in patients with myasthenia gravis, careful evaluation is necessary while considering the possibility that it may be the first symptom of a demyelinating central nervous system disease. Therefore, it is important to conduct shorter-interval monitoring and symptom screening for patients with neurological autoimmune diseases, such as myasthenia gravis, even if multiple sclerosis is not initially suspected, to achieve early detection of multiple sclerosis.     

Myasthenia gravis developing in a patient with CNS lymphoma

A patient was initially diagnosed with right basal ganglia lymphoma causing left hemiparesis. His disease was resistant to intravenous methotrexate, so he received radiation therapy with remarkable regression of the mass. However, 6 months after his initial diagnosis, he developed symmetric weakness of the proximal muscles. Electromyography was consistent with myasthenia gravis and anti-acetylcholine receptor antibodies were elevated. Treatment with pyridostigmine and corticosteroids improved his symptoms. The residual lymphoma was further treated with rituximab and temozolomide with complete resolution. Pyridostigmine and corticosteroids were stopped after 14 months of initiation with good results. Our case is the first case report of paraneoplastic myasthenia gravis developing in a patient with primary CNS lymphoma. The diagnosis of paraneoplastic myasthenia should be considered in patients with CNS lymphoma who develop muscle weakness and speech problems.     

Marked Respiratory Failure in an Ambulant Patient with Immune-mediated Necrotizing Myopathy and Anti-Kv1.4 and Anti-titin Antibodies

We herein report a case of seronegative immune-mediated necrotizing myopathy (IMNM) concurrent with anti-Kv1.4 and anti-titin antibodies. A 72-year-old Japanese woman presented with a 29-year history of fluctuating high serum creatine kinase (CK) levels followed by intermittent ptosis and respiratory muscle weakness. This case highlights the fact that marked respiratory muscle weakness requiring intubation can be seen in an ambulant patient with IMNM. Marked respiratory muscle weakness, rhabdomyolysis-like acute elevation of CK levels, and anti-striational muscle antibodies may be a characteristic constellation of findings in a distinct subgroup of patients with inflammatory myopathy with myasthenia gravis or similar symptoms.     

Efficacy and safety of Buzhong Yiqi decoction combined with western medicine in the treatment of myasthenia gravis: A protocol for systematic review and meta-analysis

Background:Myasthenia gravis is a common autoimmune disease in clinic. Although there are various ways and drugs for the treatment of myasthenia gravis in Western medicine, there are still a variety of adverse reactions. Studies have shown that Buzhong Yiqi decoction combined with Western medicine has a certain efficacy in the treatment of myasthenia gravis, but there is a lack of evidence-based medicine. The research carried out in this scheme is to systematically evaluate the efficacy and safety of Buzhong Yiqi decoction combined with Western medicine in the treatment of myasthenia gravis, and to provide reliable evidence for guiding clinical practice.Methods:English databases (the Cochrane Library, PubMed, Web of Science, Embase) and Chinese databases (China Biomedical Database, China Science and Technology Journal Database, China National Knowledge Infrastructure, Wanfang) will be searched by computer. In addition, Baidu Academic and Chinese Clinical Trial Registration Center will be searched manually. A randomized controlled clinical trial of Buzhong Yiqi decoction combined with Western medicine in the treatment of myasthenia gravis will be conducted from the establishment of the database to December 2020. The 2 researchers independently carry out data extraction and literature quality evaluation on the quality of the included study, and meta-analysis of the included literature will be carried out by using RevMan 5.3 software.Results:This study will evaluate the efficacy and safety of Buzhong Yiqi decoction combined with Western medicine in the treatment of myasthenia gravis by Quantitive MGscore, the number of Tregs cells and the content of anti-acetylcholine receptor antibody (AchR-Ab).Conclusion:This study will provide reliable evidence-based evidence for the clinical application of Buzhong Yiqi decoction combined with Western medicine in the treatment of myasthenia gravis.Ethics and dissemination:Private information from individuals will not be published. This systematic review also does not involve endangering participant rights. Ethical approval was not required. The results may be published in a peer-reviewed journal or disseminated at relevant conferences.OSF Registration number:DOI 10.17605/OSF.IO/MXUPK.     

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

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