Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011633 (dermatomyositis)
 4,181 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cell adhesion molecules participate in target-effector cell interactions in cell-mediated cytotoxicity and in leukodiapedesis in inflammatory diseases. Two ligand-receptor pairs may play a role in the adhesion of cytotoxic T cells to their targets: 1) intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1), and 2) LFA-3 and CD2. We therefore immunolocalized these molecules in myopathies where there is evidence for T cell-mediated myocytotoxicity, namely inclusion body myositis, polymyositis, and Duchenne dystrophy. Autoaggressive inflammatory cells close to invaded muscle fibers showed an increased expression of ICAM-1 and LFA-1. The nonnecrotic muscle fibers invaded by autoaggressive cells expressed ICAM-1 where their surfaces faced the invading cells. That immunoreactivity for ICAM-1 on the invading cells was distinct from that on the opposite muscle fiber surface was established by colocalization of ICAM-1 with the sarcolemmal marker dystrophin (or beta-spectrin) and was also confirmed by confocal microscopy. Leukodiapedesis in inflamed tissues is mediated by ICAM-1, LFA-3, vascular cell adhesion molecule-1 (VCAM-1), and E-selectin associated with endothelial cells. In dermatomyositis ICAM-1 was strongly expressed on endothelial cells of perimysial arterioles and venules and on some perifascicular capillaries. In all the other myopathies ICAM-1 and LFA-3 expressions were increased on endothelia of capillaries surrounded by inflammatory cells. VCAM-1 was detected in few arterioles in all diseases. E-selectin was not detected at any site in any disorder.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Expression of cell adhesion molecules in inflammatory myopathies and Duchenne dystrophy. 802 10

The genes most commonly considered when investigating immunogenetic associations with autoimmune diseases, including inflammatory muscle disease (IMD), are those encoded in the major histocompatibility complex (MHC), the T-cell receptor (TCR) genes and the immunoglobulin genes. In caucasoids HLA DR3 is associated with adult polymyositis (PM) and juvenile dermatomyositis (JDM) and is probably increased in frequency in adult DM. In inclusion body myositis (IBM) DR3 and DR1 have been separately reported to be increased but few patients have been analysed. The DR3 in IMD is almost always present on the ancestral haplotype marked by HLA-B8, C4A*Q0 and DR3 and presumably accounts for the association with C4A*Q0 which has been reported in some subgroups of IMD. In other races the associations are less clear although DR6 may be increased in blacks with PM. In PM, DR3 is strongly associated with the presence of antibodies to histidyl tRNA synthetase (Jo-1). DR52 is even more strongly associated with the presence of this autoantibody and this association can be demonstrated in black and white patients. It is unlikely that DR3 is associated with autoantibodies to other aminoacyl-tRNA synthetases or signal recognition proteins although fewer cases have been reported and racial differences may exist. Antibodies to the Pm-Scl antigen are also associated with DR3 while autoantibodies to Mi-2 may be associated with DR53. In caucasoids DR4 was increased in D-penicillamine induced IMD but again there may be inter-racial differences. Amongst caucasoids with mixed connective tissue disease (MCTD) there is an increased frequency of DR4 and this allele is associated with the development of antibodies to ribonucleoprotein (RNP). In other races the data are minimal. Very few investigations of associations between TCR polymorphisms or immunoglobulin allotypes and IMD have been reported. The phenotype Gm 3;5 has been associated with PM in caucasoids and may interact with DR3 in predisposing to disease. The Gm phenotype 1,3;5,21 has been associated with MCTD and with the development of anti-RNP, with or without MCTD, in caucasoids. Multiple genetic factors are likely to determine the development of IMD and the particular combination of alleles at predisposing loci may differ between races and according to the inducing agent. Furthermore, the predisposing genetic factors may vary between subgroups of IMD.
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PMID:Immunogenetics of inflammatory myopathies. 815 44

Although there have been considerable advances in our understanding of the immunopathogenesis of the different forms of autoimmune inflammatory myopathy, the treatment of these conditions remains largely empirical, being based upon the use of immunosuppressive and immunomodulatory therapies which, for the most part, are non-selective in their actions. Corticosteroids are usually effective in adult and childhood cases of polymyositis and dermatomyositis, but are only rarely helpful in inclusion body myositis, which is usually also unresponsive to other forms of immunosuppressive therapy. Alternate-day corticosteroid therapy has a role in patients with mild disease and as a means of minimizing the side-effects of steroids. This may also be achieved by the early introduction of a second-line agent such as methotrexate or azathioprine, which will allow more rapid steroid withdrawal and may also improve the chances of inducing a remission in more severe cases. In patients who fail to respond adequately to oral corticosteroids, or who relapse after an initial response, intravenous immunoglobulin therapy or pulse therapy with intravenous methylprednisolone are promising approaches which appeal as safer alternatives to cytotoxic drugs. However these forms of treatment will require further evaluation in prospective clinical trials. The same applies to cyclosporin, which has a more selective action on T cells, and which has been reported to be effective in resistant cases of adult and juvenile polymyositis and dermatomyositis. In the longer term, the development of more specific forms of immunotherapy for these myopathies, aimed at blocking autoantigen presentation or its interaction with T cells, awaits the identification of the target antigens and T cells which initiate the autoimmune process.
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PMID:Treatment of inflammatory myopathies. 815 49

To evaluate the value of myosonography in inflammatory myopathies ultrasound of skeletal muscles was performed in 70 patients, aged 21-82 years, suffering from histologically proven polymyositis (n = 30), dermatomyositis (n = 18), granulomatous myositis (n = 9), inclusion body myositis (n = 13), and in 102 control persons. The sensitivity of muscle ultrasound in detecting histopathologically proven disease (82.9%) was not significantly different from electromyography (92.4%) or serum creatine kinase activity (68.7%). The positive predictive value of ultrasound was 95.1%, the negative predictive value 89.2%, and the accuracy 91.3%. The different types of inflammatory myopathies presented with typical, but not specific ultrasound features. Polymyositis showed atrophy and increased echointensity predominantly of lower extremity muscles, whereas in dermatomyositis clear muscle atrophy was rare and echointensities were highest in forearm muscles. Echointensities were lower in dermatomyositis compared to poly- and granulomatous myositis. Granulomatous myositis was characterized by the highest echointensities and a tendency towards muscle hypertrophy. Severe muscle atrophy was the most impressive feature in the majority of patients with inclusion body myositis. Comparison of ultrasound and histopathological findings indicates that muscle lipomatosis has a much greater impact on muscular echointensity than does muscle fibrosis. Ultrasound of myositis improved clinical assessment of patients by supplying differential diagnostic clues based on precise muscle size measurements and identification of mesenchymal abnormalities, particularly muscle lipomatosis.
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PMID:Muscular ultrasound in idiopathic inflammatory myopathies of adults. 850 7

We investigated the profiles of cytokine mRNA expression in muscle in 15 cases of inflammatory myopathy (IM) (5 each of polymyositis, inclusion body myositis, and dermatomyositis) and in 10 controls (5 of Duchenne dystrophy and 5 non-weak subjects). Expressions of the predominantly T cell-derived cytokines (interleukin (IL)-2, IL-4, IL-5, and interferon-gamma (IFN-gamma), of the predominantly macrophage-derived cytokines (IL-1, IL-6, and tumor necrosis factor-alpha (TNF-alpha)), as well as cytokines that can be of either T cell or macrophage origin (granulocyte-macrophage colony stimulating factor (GM-CSF) and transforming growth factor beta 1 (TGF-beta 1) and TGF-beta 2), were monitored by the reverse transcriptase-PCR method. The expression of T cell cytokine mRNAs for IL-2, IL-5, and IFN-gamma was generally weak or inconsistent. IL-4 mRNA expression was consistently moderate to strong in polymyositis but generally weak or absent in the other IMs. The expression of macrophage cytokine mRNAs for IL-1 alpha and IL-1 beta was weak or absent in all cases. Variable TNF-alpha mRNA expression was observed in 12 of 15 IM cases and faint or weak expression in 5 of 10 controls. Very strong GM-CSF expression was detected, but only on boosted PCR, in 12 of 15 cases of IM but in none of the controls. IL-6 was expressed only weakly or inconsistently. In contrast to the variable expression of several of the above mentioned cytokine mRNAs, all IM specimens strongly expressed TGF-beta 1 mRNA and 12 of 15 strongly expressed TGF-beta 2 mRNA. Thus, with the exception of IL-4 expression in polymyositis, a similar pattern of cytokine mRNA expression exists in the different types of IMs. Moreover, this pattern resembles that detected in non-weak and DD controls, although expression is generally weaker in the non-weak controls. The findings suggest that in IM muscle a sustained secretion of cytokines by T cells or of IL-1 by macrophages is not a prerequisite for operation of the immune effector response and that muscle may not be the site of ongoing sensitization.
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PMID:Analysis of cytokine expression in muscle in inflammatory myopathies, Duchenne dystrophy, and non-weak controls. 855 29

The inflammatory myopathies consist of three distinct groups: dermatomyositis, polymyositis, and inclusion body myositis. Dermatomyositis is distinguished by its characteristic rash, while polymyositis is a diagnosis of exclusion. Inclusion body myositis is characterized by early involvement of distal muscle groups and the quadriceps. Definitive diagnosis is made by muscle biopsy, which demonstrates histological features characteristic for each disorder. Immune mechanisms play a role in the pathogenesis of the inflammatory myopathies. A complement-mediated microangiopathy is seen in dermatomyositis, while there is evidence for a T cell-mediated process in polymyositis and inclusion body myositis. Treatment with prednisone is helpful to a majority of patients for a period of time. Immunosuppressive drugs have met with limited success. We describe a group of patients with dermatomyositis, resistant to available therapies, whose muscle strength, skin changes, and muscle biopsies improved significantly during treatment with intravenous immune globulin. The treatment of polymyositis and inclusion body myositis with intravenous immune globulin is currently under study.
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PMID:Update on the use of intravenous immune globulin in the treatment of patients with inflammatory muscle disease. 861 95

Inclusion body myositis has been recently recognized as a clinical entity although its exact definition remains uncertain. Initially considered to be an inflammatory dermatomyositis, inclusion body myositis can actually take on three specific forms: disseminated muscle atrophy and weakness, pseudopolymyositis, or pseudo-degenerative disease. Inclusion body myositis is different from non-inflammatory neuromuscular diseases with vacuoles. Abnormal deposits are seen within the muscle fiber may contain amyloid substance, beta-amyloid precursor, ubiquitin, antichymotrypsin, protein tau, apolipoprotein E and even prions. The signification of these deposits is unknown. Deletions in mitochondrial DNA have been demonstrated but do not appear to play a causal role. More and more hereditary forms are being recognized and certain may be related to an abnormality in chromosome 9.
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PMID:[Inclusion body myositis]. 869 77

We studied mitochondrial function in inflammatory myopathies, using cytochrome c oxidase (COX) reaction on muscle biopsy samples from 30 patients (15 with dermatomyositis, 12 with polymyositis, and 3 with inclusion body myositis) and 30 age-matched controls. We also performed immunocytochemistry for COX II and COX IV subunits in 7 of these patients who had COX deficiency. COX-deficient fibers were a constant finding in patients or controls older than 65 years and the percentage of COX-deficient fibers correlated with age in both patients and controls. Focal COX deficiency was found in 24 patients (13 of 15 with dermatomyositis, 8 of 12 with polymyositis, and 3 of 3 with inclusion body myositis) and 18 controls. The percentages of COX-deficient fibers were higher in patients with inflammatory myopathies (range: 0-4.7%; mean: 1.2%) than in age-matched controls (range: 0-1.9%; mean: 0.4%) (P < 0.01). In the subgroup of patients under age 65, COX-deficient fibers were more frequent in dermatomyositis than in polymyositis (mean: 0.8% vs 0.2%, P = 0.02). In patients with dermatomyositis, capillary loss correlated positively with COX deficiency (P < 0.02). Immunocytochemistry for COX II and IV showed that 82% of COX-negative fibers were COX II-negative and 26% were COX IV-negative, suggesting that proteins encoded by mitochondrial DNA are predominantly, but not exclusively, involved in COX deficiency. We conclude that mitochondrial dysfunction and COX deficiency can occur in inflammatory myopathies. Such a mitochondrial dysfunction is not solely related to the aging process. We suggest that muscle ischemia contributes to mitochondrial dysfunction in dermatomyositis.
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PMID:Cytochrome c oxidase deficiencies in the muscle of patients with inflammatory myopathies. 874 Feb 35

In polymyositis and sporadic inclusion body myositis, clonal expansion of CD8+ cells which are primed to recognize previously unknown muscle antigens occurs. Compared with sporadic inclusion body myositis, however, in which the T-cell response may not be antigen driven, there is in polymyositis an overexpression of certain T-cell receptor gene families among the autoinvasive T-cells. Although studies on the endomysial expression of cytokines and cell adhesion molecules have provided additional support for the concept of an ongoing immune process, the site of sensitization and the mechanism by which the autoimmune process is triggered remains to be established. In dermatomyositis, a multiorgan disease, evidence exists that the complement-mediated microvascular injury by the putative antibody may not be limited to the endomysial vessels but may also involve the blood vessels in the dermis. The antigenic target on the endothelial cell in dermatomyositis patients and the pathogenic role of the recently studied anti-Mi-2 antibody directed against a helicase are still to be determined.
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PMID:The immunopathologic and inflammatory differences between dermatomyositis, polymyositis and sporadic inclusion body myositis. 883 18

Automatic decomposition electromyography (ADEMG) is a commercially available software package with installed reference values that enables the objective measurement of motor unit action potentials (MUAPs). To assess the diagnostic yield of this package in idiopathic inflammatory myopathies (IIM) we performed bicepts brachii ADEMG in 17 patients with polymyositis, dermatomyositis and inclusion body myositis. Results were compared with those in 12 controls, and with the results of conventional EMG of the biceps and other muscles. Decreased mean values for MUAP duration occurred significantly more frequently in IIM patients than in controls; other MUAP characteristics did not differ. In IIM patients, decreased mean amplitude and increased mean number of turns occurred significantly less frequently on ADEMG than did corresponding abnormalities on conventional biceps EMG. Decreased mean values for duration and amplitude, and increased mean values for number of turns were seen significantly less often on ADEMG than corresponding abnormalities on conventional EMG of four different, individually chosen muscles. Overall evaluation of ADEMG resulted in a diagnosis of "possible myopathy" in 1 and "probable myopathy" in 8 patients, whereas overall evaluation of conventional EMG led to a diagnosis "suggestive of IIM" in 13 patients. We conclude that, although measurement of mean MUAP duration might be valuable in IIM diagnosis, our results do not favour the use of biceps brachii ADEMG and the installed reference values for the diagnosis of IIM. We suggest modifications to improve ADEMG's applicability.
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PMID:Automatic decomposition electromyography in idiopathic inflammatory myopathies. 886 92


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