1/201. Treatment of severe myasthenia gravis with protein A immunoadsorption and cyclophosphamide.myasthenia gravis (MG) is an autoimmune disease of the neuromuscular junction caused by antibodies against the nicotinic acetylcholine receptor (AChR-Ab). We report a 16-year-old girl with severe MG who showed a poor response to plasma exchange and tryptophan-linked polyvinylalcohol gel immunoadsorption. Further improvement of muscle strength and decline of AChR-Ab could be achieved after initiation of protein-A immunoadsorption (PA-IA). maintenance therapy with PA-IA and intravenous pulses of cyclophosphamide resulted in a stabilisation of the disease, with a complete remission during the follow-up period of six months. We suggest that PA-IA may be valuable and safe in the management of patients with severe MG, and maintenance therapy with PA-IA and cyclophosphamide may prevent serious and potentially life-threatening relapses of the disease.- - - - - - - - - - ranking = 1keywords = receptor (Clic here for more details about this article) |
2/201. Development of myasthenia gravis after interferon alpha therapy.Interferon (IFN) alpha is now used in the treatment of some malignant diseases and chronic viral hepatitis. There have been several reports of development of autoantibodies and autoimmune diseases or the deterioration of preexisting disorders in patients under treatment. We enclose a case of myasthenia gravis (MG) which developed after six weeks of treatment as fluctuating bilateral ptosis, intermittent diplopia, and mild weakness of limb and neck muscles. A test dose of edrophonium chloride was administered, resulting in improved muscle strength. Elevated anti acetylcholine receptor (AChR) antibody titer was found. Single fiber electromyography showed an increased jitter from extensor digitorum communis, frequently accompanied by transmission blocking. Repetitive electric 3 Hz stimulation of the abductor pollicis brevis muscle, revealed an abnormal decrement of 28% in compound motor action potential. myasthenia gravis was diagnosed and the patient was given pyridostigmine, immunoglobulines and prednisone with benefit. Six months latter he developed an acute myasthenic crisis with severe respiratory failure and high anti AChR antibody titer. IFN-alpha can induce MG or simply manifests a preexisting subclinical disease, but otherwise its therapeutic efficacy in MG has been shown in experimental and clinical studies. Autoimmune mechanisms, as the release of different cytokines as IFN, by immunocompetent cells, may be involved in the pathogenesis of both MG and chronic active hepatitis. Autoantibody production against postsynaptic membrane structures by IFN-alpha could be the underlying pathophysiology.- - - - - - - - - - ranking = 1keywords = receptor (Clic here for more details about this article) |
3/201. Congenital myasthenic syndrome caused by a mutation in the Ets-binding site of the promoter region of the acetylcholine receptor epsilon subunit gene.Forty-two missense, truncation, or splice-site mutations of the acetylcholine receptor (AChR) subunit genes have been reported to date in patients with congenital myasthenic syndromes. Here we report a homozygous mutation, epsilon-155G --> A, in the promoter region of the AChR epsilon subunit gene that converts the Ets-binding site of the promoter region from CGGAA to CAGAA. The asymptomatic parents and brother are heterozygous and an affected sister is homozygous for epislon-155G --> A. The Ets-binding site mediates synapse specific expression of the AChR epsilon subunit gene. An identical G-to-A mutation in the mouse Ets-binding site was previously shown to decrease the binding affinity of the Ets-binding site for the GA binding protein, a transactivating factor for the Ets-binding site, and to reduce the synapse specific expression of the epsilon subunit. The decreased synaptic expression of the epsilon subunit readily accounts for the congenital myasthenic phenotype.- - - - - - - - - - ranking = 5keywords = receptor (Clic here for more details about this article) |
4/201. myasthenia gravis and peripheral neuropathy in an Amazon indigenous female.A 15 year-old female presented with anti-acetylcholine receptor antibody-positive myasthenia gravis and electrophysiological signs of sensory peripheral neuropathy. The repetitive stimulation test showed decremental response of 31% in the median nerve. The clinical picture improved with prostigmine, corticosteroids, plasmapheresis and thymectomy. This is the first case report of an Amazon indigenous patient with myasthenia gravis.- - - - - - - - - - ranking = 1keywords = receptor (Clic here for more details about this article) |
5/201. Spontaneously occurring neutralizing antibodies against granulocyte-macrophage colony-stimulating factor in patients with autoimmune disease.There is increasing evidence that spontaneous anticytokine autoantibodies are associated with chronic infections and autoimmune diseases. We report the sporadic occurrence in autoimmune diseases of such autoantibodies to granulocyte-macrophage colony-stimulating factor (GM-CSF), a cytokine involved in inflammation and the regulation of proliferation, differentiation and function of granulocytic and monocytic cell lineages. In 41 of 425 patients tested, we found low to moderate levels of autoantibodies binding to GM-CSF in serum or plasma. These were most prevalent in patients with myasthenia gravis (MG). However, neutralizing autoantibodies against GM-CSF were very rare, being found in only three patients. Two had autoimmune MG, one with thymoma (Patient A) and the other (Patient B) with 'seronegative' MG, i.e. without the antiacetylcholine receptor autoantibodies characteristic of most MG patients, and a third (Patient D) had multiple sclerosis. Only very limited amounts of Patient A and Patient D serum/plasma were available for analysis and therefore further studies were carried out on the more plentiful samples from Patient B. The anti-GM-CSF autoantibodies of Patient B were predominantly polyclonal immunoglobulin g and strongly neutralized recombinant human (rh) GM-CSF derived from different expression systems. They had similar immunological and immunochemical characteristics to anti-GM-CSF antibodies that developed in immunocompetent colorectal carcinoma patients following (rh)GM-CSF therapy. In serial samples from Patient B, the anti-GM-CSF autoantibodies were undetectable from diagnosis at age 8 years until at least age 13, but then developed spontaneously during (temporary) withdrawal of immunosuppressive treatment. Their neutralizing activity has persisted since their first detection at age 15 years 1 month, and was at its highest level recently at age 17 years 7 months. There was no obvious association with other autoimmune phenomena, nor were any haematological deficiencies overtly manifested, suggesting that any loss of GM-CSF function may have been compensated for by other cytokines.- - - - - - - - - - ranking = 1keywords = receptor (Clic here for more details about this article) |
6/201. Exacerbation of myasthenia gravis in a patient after interferon-beta treatment for chronic active hepatitis c.We report the case of a 53-year-old female patient, who developed bilateral blepharoptosis, limb weakness, dysphagia, and dyspnea several days after human natural interferon-beta (IFN-beta) treatment for chronic active hepatitis c. A positive edrophonium test, an elevated anti-acetylcholine receptor antibody titer, and decrements in the amplitude of muscle action potentials evoked by repetitive stimulation confirmed the diagnosis of myasthenia gravis (MG). Since she had been suffering from drooping of her right eyelid, fluctuating diplopia and easy fatiguability of limbs before receiving IFN-beta, her symptoms of MG were considered to be exacerbated by IFN-beta. It is recommended that IFN-beta should be used with particular care in patients with known MG or its compatible symptoms.- - - - - - - - - - ranking = 1keywords = receptor (Clic here for more details about this article) |
7/201. Cisatracurium in a myasthenic patient undergoing thymectomy.PURPOSE: The report investigates cisatracurium neuromuscular block in a myasthenic patient undergoing thymectomy. CLINICAL FEATURES: A myasthenic patient (Osserman II B) was prepared preoperatively with 240 mg x day(-1) pyridostigmine. The neuromuscular block produced by 0.05 mg x kg(-1) cisatracurium was monitored by Datex electromyography. The electromyographic response was compared with that in a control group of five non-myasthenic patients. In the myasthenic patient, cisatracurium resulted in a rapid onset of complete (97-98%) neuromuscular block, while a slow onset of partial (80-90%) block was achieved in the control group. Also, administration of 0.05 mg x kg(-1) neostigmine at the end of surgery reversed the neuromuscular block of cisatracurium in the non-myasthenic patients, but did not change the rate of spontaneous recovery in the myasthenic patient. CONCLUSION: The myasthenic patient is sensitive to cisatracurium, as evidenced by a more rapid onset and more marked neuromuscular block compared with the control non-myasthenic patients. This may be attributed to the decreased number of functional endplate acetylcholine receptors in the myasthenic patient, with a consequent decrease of the safety margin of neuromuscular transmission. Also, in contrast with the control group, the rate of recovery from neuromuscular block in the myasthenic patient was not enhanced by neostigmine at the end of surgery. This may be attributed to the prior inhibition of acetylcholinesterase by the preoperative pyridostigmine, as well as by possible desensitization of the cholinergic receptors secondary to prolonged pyridostigmine therapy.- - - - - - - - - - ranking = 2keywords = receptor (Clic here for more details about this article) |
8/201. Pseudo-myasthenia gravis and thymic hyperplasia in Graves' disease.BACKGROUND: Diagnostic confusion between thyroid disease and myasthenia gravis (MG) can arise because the two may have similar clinical features, and also because of the more frequent coexistence of these autoimmune disorders in the same individual. In MG, autoantibodies directed against the acetylcholine receptor result in muscle weakness. Thymic pathology is well recognized in MG, with thymic hyperplasia frequent in early onset MG and thymoma more common in later onset MG. In Graves' disease, autoantibodies against thyroid antigens result in hyperthyroidism. A seldom-recognized feature of Grave's disease is the occurrence of an enlarged thymus (thymic hyperplasia) on chest CT, or of thymic lymphoid hyperplasia pathologically. CASE STUDY: This report describes a case in which the discovery of a mediastinal mass during imaging of the thyroid, and the presence of myasthenic-like symptoms, in a patient with Graves' disease prompted investigations into whether the patient also had MG. RESULTS: Despite symptoms which strongly suggested MG, subsequent investigations did not confirm the diagnosis, and treatment of Grave's lead to a resolution of the symptoms and regression of the thymic enlargement seen on CT. CONCLUSIONS: The case study highlighted clinical similarities between Grave's disease and myasthenia gravis which might cause diagnostic confusion, and also the investigations which are useful in order to differentiate the two diseases. In addition to common clinical features, the autoimmune diseases Grave's disease and myasthenia gravis may both produce radiological thymic enlargement.- - - - - - - - - - ranking = 1keywords = receptor (Clic here for more details about this article) |
9/201. somatostatin receptor scintigraphy in thymoma imaging method and clinical application.somatostatin receptor scintigraphy with 111In-[DTPA-D-Phe1]-octreotide has the potential for visualizing primary and recurrent thymomas in patients with myasthenia gravis, whereas thymic hyperplasias fail to accumulate somatostatin analog peptides. We demonstrate somatostatin receptor imaging findings in a patient with a mixed encapsulated thymoma which exhibited intense 111In-[DTPA-D-Phe1]-octreotide uptake in early and late scans. In another patient with a history of malignant thymoma 111In-[DTPA-D-Phe1]-octreotide accumulation was clearly seen in a mass suspected to be a recurrence. This paper describes the imaging protocol including Single Photon Emission Computed tomography (SPECT) and discusses the clinical applications of this feasible functional imaging method in patients with thymomas.- - - - - - - - - - ranking = 6keywords = receptor (Clic here for more details about this article) |
10/201. myasthenia gravis, thymoma, intestinal pseudo-obstruction, and neuronal nicotinic acetylcholine receptor antibody.intestinal pseudo-obstruction occurs rarely in patients with myasthenia gravis (MG) and thymoma. The etiology of the intestinal pseudo-obstruction remains to be elucidated, although an autoimmune mechanism is postulated. We present the first report of neuronal nicotinic acetylcholine receptor (AChR)-specific antibody in a patient with seropositive MG, malignant thymoma, and intestinal pseudo-obstruction. This finding provides evidence that intestinal pseudo-obstruction associated with thymoma and possibly other neoplasms may be related to antibodies against the neuronal nicotinic receptors at autonomic ganglia.- - - - - - - - - - ranking = 6keywords = receptor (Clic here for more details about this article) |
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