TL;DR: Patients with myasthenia gravis should be classified into subgroups to help with therapeutic decisions and prognosis, and additional immunomodulatory drugs are emerging, but therapeutic decisions are hampered by the scarcity of controlled studies.
Abstract: Myasthenia gravis is an autoimmune disease that is characterised by muscle weakness and fatigue, is B-cell mediated, and is associated with antibodies directed against the acetylcholine receptor, muscle-specific kinase (MUSK), lipoprotein-related protein 4 (LRP4), or agrin in the postsynaptic membrane at the neuromuscular junction. Patients with myasthenia gravis should be classified into subgroups to help with therapeutic decisions and prognosis. Subgroups based on serum antibodies and clinical features include early-onset, late-onset, thymoma, MUSK, LRP4, antibody-negative, and ocular forms of myasthenia gravis. Agrin-associated myasthenia gravis might emerge as a new entity. The prognosis is good with optimum symptomatic, immunosuppressive, and supportive treatment. Pyridostigmine is the preferred symptomatic treatment, and for patients who do not adequately respond to symptomatic therapy, corticosteroids, azathioprine, and thymectomy are first-line immunosuppressive treatments. Additional immunomodulatory drugs are emerging, but therapeutic decisions are hampered by the scarcity of controlled studies. Long-term drug treatment is essential for most patients and must be tailored to the particular form of myasthenia gravis.
TL;DR: Current information about the epidemiology, immunopathogenesis, clinical presentations, diagnosis, and treatment of acquired myasthenia gravis is provided, including emerging therapeutic strategies.
Abstract: Acquired myasthenia gravis (MG) is an autoimmune disorder of the neuromuscular junction in which patients experience fluctuating skeletal muscle weakness that often affects selected muscle groups preferentially. The target of the autoimmune attack in most cases is the skeletal muscle acetylcholine receptor (AChR), but in others, non-AChR components of the neuromuscular junction, such as the muscle-specific receptor tyrosine kinase, are targeted. The pathophysiological result is muscle endplate dysfunction and consequent fatigable muscle weakness. Clinical presentations vary substantially, both for anti-AChR positive and negative MG, and accurate diagnosis and selection of effective treatment depends on recognition of less typical as well as classic disease phenotypes. Accumulating evidence suggests that clinical MG subgroups might respond differently to treatment. In this Review, we provide current information about the epidemiology, immunopathogenesis, clinical presentations, diagnosis, and treatment of MG, including emerging therapeutic strategies.
TL;DR: Thymectomy improved clinical outcomes over a 3-year period in patients with nonthymomatous myasthenia gravis, with fewer treatment-associated symptoms related to immunosuppressive medications and lower distress levels related to symptoms.
Abstract: BackgroundThymectomy has been a mainstay in the treatment of myasthenia gravis, but there is no conclusive evidence of its benefit. We conducted a multicenter, randomized trial comparing thymectomy plus prednisone with prednisone alone. MethodsWe compared extended transsternal thymectomy plus alternate-day prednisone with alternate-day prednisone alone. Patients 18 to 65 years of age who had generalized nonthymomatous myasthenia gravis with a disease duration of less than 5 years were included if they had Myasthenia Gravis Foundation of America clinical class II to IV disease (on a scale from I to V, with higher classes indicating more severe disease) and elevated circulating concentrations of acetylcholine-receptor antibody. The primary outcomes were the time-weighted average Quantitative Myasthenia Gravis score (on a scale from 0 to 39, with higher scores indicating more severe disease) over a 3-year period, as assessed by means of blinded rating, and the time-weighted average required dose of prednison...
TL;DR: The clinical course of MG was significantly influenced by age and gender, and these need special attention in managing patients, and novel drugs need to be developed to increase the number as well as normal functioning of the AChRs and other components of the neuromuscular system.
Abstract: Between 1940 and 2000 a total of 1976 patients with myasthenia gravis (MG) were studied. Diagnosis was made by improvement in weakness after anticholinesterase medication. The historical developments in diagnosis and treatment of MG are reviewed. We analyzed the clinical course of MG as influenced by age, gender, thymectomy, thymomectomy, and the presence of antibodies to acetylcholine receptors (AChR). The clinical course of MG was significantly influenced by age and gender, and these need special attention in managing patients. The most severe level of weakness and high mortality occurred during the first 1 to 2 years of the disease, after which many patients experienced improvement. For treating MG patients the usefulness of thymectomy remains to be proven, and novel drugs need to be developed to increase the number as well as normal functioning of the AChRs and other components of the neuromuscular system.