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Query: UMLS:C0027121 (myositis)
 4,538 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The idiopathic inflammatory myopathies (IIM) are a heterogeneous group of systemic diseases that include the familiar disease entities of dermatomyositis (DM), polymyositis (PM), and inclusion body myositis (IBM). A subset of patients has unique autoantibodies which are specific for IIM (myositis specific autoantibodies; MSAs). We studied the clinical and serological characteristics of IIM in 125 Dutch patients. Sera were analysed by immunoblotting, enzyme-linked immunosorbent assay, and immunoprecipitation. The most frequently encountered MSA was the anti-Jo-1 autoantibody (20%), followed by anti-tRNAHis (6%), anti-Mi-2 (6%), and anti-SRP (4%). The presence of certain MSAs was clearly associated with specific clinical characteristics. Anti-Jo-1 and anti-tRNAHis were associated with the anti-synthetase syndrome, anti-SRP with PM with severe myalgia and arthralgia and a moderate response to immunosuppressive treatment. A novel finding was the presence of anti-Mi-2, not only in DM, but also in PM. MSAs were frequently present in DM/PM sera, but were hardly ever detected in the sera of IBM patients. The few IBM patients with MSAs demonstrated a significant response to immunosuppressive treatment. It can be concluded that MSAs define specific clinical syndromes within the spectrum of IIM and that they can assist in the differential diagnosis and treatment plan of these enigmatic disorders by virtually excluding IBM by their presence, and by potentially identifying a subgroup of steroid-responsive IBM patients.
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PMID:Clinical and serological characteristics of 125 Dutch myositis patients. Myositis specific autoantibodies aid in the differential diagnosis of the idiopathic inflammatory myopathies. 1195 71

Inflammatory muscular diseases of adult and child consist of dermatomyositis (DM), polymyositis (PM) and inclusion body myositis (IBM). Muscular biopsy takes a seminal place in their diagnosis, through analysis of the topography and clustering of individual histological lesions: endomysial, perimysial and perivascular inflammation, muscular necrosis with regeneration, fibre modifications, fibrosis, micro-angiopathy. They can be associated with collagen diseases or malignant tumors that usually precede them. IBM seems somewhat apart among inflammatory myopathies, being characterised by the association of neurogenic and myogenic features and the presence of vacuoles containing filaments with an accumulation of proteins previously reported in Alzheimer's disease (beta amyloid protein, tau, ubiquitin,.). Inflammation is of various intensity, lacking in familial IBM (hereditary inclusion body myopathy) that otherwise shares the same histologic characteristics as sporadic forms. Other inflammatory muscular diseases: focal myositis, eosinophilic polymyositis, are less frequent. Macrophagic myofasciitis, viral myositis and drug induced myositis are discussed in other articles.
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PMID:[Histological data in inflammatory myositis]. 1196 88

The group of idiopathic inflammatory myopathies encompasses polymyositis, dermatomyositis and inclusion body myositis. These diseases share the following features: progressive muscle weakness, an increase in serum creatine kinase activity and the presence of mononuclear cell infiltrates in the muscle biopsy. Polymyositis, dermatomyositis and inclusion body myositis are differentiated on the basis of the distribution of muscle weakness, and specific histopathological features. Many specialties may see these patients as the clinical presentation can vary widely and may be atypical, requiring further diagnostic procedures. A 40-year-old man with a heliotrope rash and periorbital oedema, but no muscle involvement, was diagnosed with dermatomyositis sine myositis. He was successfully treated with corticosteroids but died later of cardiac failure. A 72-year-old man with a pulmonary malignancy subsequently developed the clinical features of dermatomyositis. Steroid therapy diminished the complaints but he died of pulmonary embolism. A 54-year-old woman with the clinical features of inclusion body myositis did not have rimmed vacuoles in her muscle biopsy specimen and was initially erroneously diagnosed with polymyositis, for which she was treated with corticosteroids, but without beneficial effect.
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PMID:[Three patients with divergent presentations of idiopathic inflammatory myopathy]. 1203 18

The most recent evidence from population-based cohort studies confirms the association between malignancy and dermatomyositis and polymyositis. These studies show an even stronger association between polymyositis and malignancy than previous studies, suggesting less misclassification. This is particularly true of one study that used pathologic criteria to distinguish between myositis subtypes. Recent data also confirm that the association for dermatomyositis and polymyositis is not purely caused by diagnostic suspicion or surveillance bias. More data are still required to determine individual cancer risks, although it appears that ovarian and lung cancer are associated with dermatomyositis while lung cancer and non-Hodgkin's lymphoma are associated with polymyositis. An association between malignant disease and inclusion body myositis has also been verified for the first time. Of interest, too, is the increasing number of reports documenting cases in which the clinical course of the myositis mirrors that of the cancer, supporting the notion that in some instances, myositis is a paraneoplastic disorder.
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PMID:Malignancy in patients with inflammatory myopathy. 1221 47

The initial approach to the treatment of patients with inflammatory myopathy is critical in determining the subsequent course and outcome. Prolonged administration of high doses of corticosteroids should be avoided and a second-line agent such as methotrexate or azathioprine should be introduced earlier rather than later. Intravenous immunoglobulin therapy has an important place if the myositis remains active, particularly in patients with dermatomyositis, and is the treatment of choice in patients with immunodeficiency who are not controlled by corticosteroids. In more resistant cases of polymyositis or dermatomyositis it may be necessary to use cyclophosphamide, cyclosporin or the promising newer immunosuppressive agents mycophenolate mofetil or tacrolimus to achieve disease control. The treatment of inclusion body myositis remains unsatisfactory but a trial of prednisolone and methotrexate is warranted in selected patients.
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PMID:Inflammatory myopathies: how to treat the difficult cases. 1246 34

The inflammatory myopathies - myositis - encompass a heterogeneous group of chronic muscle disorders of unknown origin and with varying prognoses. New clinical phenotypes of myositis have been identified since the most widely used classification criteria were proposed in 1975. Based on clinical and histopathological features, inclusion body myositis was identified. Furthermore, the myositis-specific autoantibodies may also identify different clinical phenotypes and serve as prognostic markers. The different classifications and inclusion criteria that have been used in different studies make some epidemiological data uncertain. In order to improve our knowledge of causative factors, as well as of pathogenic mechanisms, there is a need for revision and also for an international acceptance of the classification criteria. During recent years, our knowledge has increased regarding the role of some genetic and environmental factors that could affect susceptibility for developing myositis as well as the prognosis. Whether there is an association between myositis and malignancies has been a subject of controversy for many years and recent epidemiological data have brought some clarification on this issue.
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PMID:Idiopathic inflammatory myopathies - myositis. 1247 76

The hallmark of the inflammatory myopathies is muscle weakness. Although this feature can lead to significant disability and impairment of activities of daily living, its initial presentation may not be recognized early. Older individuals, in particular, may feel that the changes caused by myositis reflect the effects of aging rather than those of a disease process, and diagnosis, therefore, may be delayed. This factor has negative impact on the response to therapy. Inclusion body myositis, with its insidious onset in older people, and laboratory findings which may not be markedly abnormal, presents a diagnostic challenge. DM, with its characteristic symptomatic rash, is generally brought to medical attention more quickly. Another area of diagnostic concern occurs when associated organ involvement precedes myopathy. This has been observed, for example, with interstitial lung disease, and again represents a challenge to physicians. In this connection, the antisynthetase syndrome presenting with fevers, Raynaud's features, arthritis, or pulmonary involvement may not initially be recognized as a manifestation of inflammatory muscle disease. Each subgroup of IIM may present with a variety of extramuscular features that can complicate diagnosis and alter therapy and prognosis. This is particularly true for the pulmonary, GI, and cardiac manifestations and when cancer is associated with myositis. For these reasons, such features of IIM should be carefully evaluated, treated, and monitored over the course of the illness; in some cases these may play a greater role in determining the outcome of patients with IIM than the muscle involvement itself. It is hoped that in the future increased familiarity with the manifestations of the inflammatory myopathies, together with a better understanding of the underlying pathogenesis, will lead to more rapid diagnosis and more effective treatments.
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PMID:Clinical presentation of the idiopathic inflammatory myopathies. 1250 74

Epidemiologic studies have helped to define the prevalence and incidence of PM, DM, and IBM and have highlighted differences in risk between men and women and in the age at onset for the different forms of myositis. Additionally, these studies have shown that there is a substantially higher risk of PM and DM in certain racial groups which is likely to be genetically determined. These differences are all likely to be fundamental in terms of the pathogenesis of these diseases but, as yet, their full significance remains uncertain. They do, however, suggest that the interplay between genetic and environmental initiating factors is different in the three disorders. Additional population-based studies in homogeneous racial groups, in parallel with studies of susceptibility genes for autoimmune disease, such as those encoding the MHC and inflammatory cytokines, are needed to throw further light on the role of genetic factors in the pathogenesis of the IIMs [47]. Because of the paucity of epidemiologic data on IBM, further studies are required to determine the degree of variation in prevalence in different populations and racial groups, as well as the consistency of the male association and age spectrum of manifestations of the disease. The particularly strong association with DR3 in this form of IIM [48] clearly points to the importance of genetic factors in pathogenesis, but further studies of DR3-associated genes in the MHC and of other candidate genes are needed to define more precisely the genes that convey susceptibility to the disease in different racial groups. Epidemiologic studies also have the potential to identify environmental factors that may play a part in disease initiation in genetically susceptible individuals. Seasonal patterns of disease onset have been reported, particularly in patients with DM [49-51] as well as seasonal variation in the frequency of relapses [52], pointing to the probable involvement of intercurrent infections, ultraviolet light exposure, or other environmental factors in disease initiation and reactivation. Further prospective studies are required to determine the contribution of environmental exposures and how they interact with genetic susceptibility factors to lead to myositis. One of the major limitations of a number of the previous epidemiologic studies is the lack of precision in the diagnostic criteria used and the classification of cases of IIM. The Bohan and Peter criteria [1] which were used in most studies after 1975, were introduced before IBM was recognized as an entity distinct from PM; most of the published incidence and prevalence figures for PM are therefore likely to be inaccurate. Multicentered, interdisciplinary, prospective studies, incorporating comprehensive clinical, laboratory, and pathologic information, are needed to develop and validate better diagnostic and classification criteria and to determine the true prevalence and incidence of the many forms of IIM.
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PMID:Idiopathic inflammatory myopathies: epidemiology, classification, and diagnostic criteria. 1251 Jun 64

BACE1 and BACE2 are recently discovered enzymes participating in processing of amyloid beta precursor protein (AbetaPP). Their discovery is contributing importantly to understanding the mechanism of amyloid-beta generation, and hence the pathogenesis of Alzheimer's disease (AD). Sporadic inclusion-body myositis (s-IBM) and hereditary inclusion-body myopathy (h-IBM) are progressive muscle diseases in which overproduction of AbetaPP and accumulation of its presumably toxic proteolytic product amyloid-beta (Abeta) in abnormal muscle fibers appear to play an important upstream role in the pathogenic cascade. In normal human muscle AbetaPP was also shown to be present and presumably playing a role (a) at neuromuscular junctions and (b) during muscle development. To investigate whether BACE1 and BACE2 play a role in normal and diseased human muscle, we have now studied them by immunocytochemistry and immunoblotting in 35 human muscle biopsies, including: 5 s-IBM; 5 chromosome-9p1-linked quadriceps-sparing h-IBM; and 25 control muscle biopsies. In addition, expression of BACE1 and BACE2 was studied in normal cultured human muscle. Our studies demonstrate that BACE1 and BACE2 (a) are expressed in normal adult muscle at the postsynaptic domain of neuromuscular junctions, and in cultured human muscle; (b) are accumulated in the form of plaque-like inclusions in both s-IBM and h-IBM vacuolated muscle fibers; and (c) are immunoreactive in necrotizing muscle fibers. Accordingly, BACE1 and BACE2 participate in normal and abnormal processes of human muscle, suggesting that their functions are broader than previously thought.
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PMID:BACE1 and BACE2 in pathologic and normal human muscle. 1261 21

We report a 17-year-old girl with an unusual neuromuscular disorder characterised by slowly progressive proximal muscle weakness whose muscle biopsy showed multiple ring fibres and numerous rimmed vacuoles as well as intracytoplasmic and intranuclear inclusions of the inclusion body myositis-type. The clinical features of the presented case, manifested by the onset of the disease in early childhood, delayed motor development, short stature, lordosis and joint contractures were suggestive of congenital myopathy. The coexistence of ring fibres, rimmed vacuoles and inclusion-body myositis-type inclusions in a child with congenital myopathy has not been previously reported.
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PMID:Congenital myopathy with abundant ring fibres, rimmed vacuoles and inclusion body myositis-type inclusions. 1269 May 67


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