Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027121 (myositis)
 4,538 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Antibodies to a 56 kDa nuclear protein have been found in the sera of 85% of patients with myositis using an immunoblotting technique. This auto-antibody appears to be relatively disease-specific though more frequently detectable in both adult and childhood onset dermatomyositis. In adult patients with myositis the anti-56 kDa antibody level reflects disease activity. This antibody is thus much more frequently found than previously described disease-specific autoantibodies in patients with myositis such as the Jo-1 antibody, and may represent a useful diagnostic aid in patients with muscle weakness.
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PMID:Autoantibodies against a nuclear 56 kDa protein: a marker for inflammatory muscle disease. 261 71

Evidence of autoimmune muscle injury and of systemic autoimmunity is seen in PM and DM. In typical PM, a cell-mediated attack on muscle fibers by CD8+ cytotoxic T cells predominates, directed at an unknown antigen. In DM, vascular injury is prominent, with loss of muscle capillaries and ischemic muscle damage, apparently mediated by local complement activation in small muscle vessels. Although humoral immunity seems more important in the pathogenesis of DM, serum autoantibodies are commonly found in both forms. About one third of patients have MSAs, whereas others have less specific antibodies such as anti-U1RNP, often associated with overlap syndromes involving myositis. MSAs are mutually exclusive and define characteristic clinical subgroups. Antibodies to five of the aminoacyl-tRNA synthetases are each associated with an "antisynthetase syndrome" marked by myositis, ILD, arthritis, and other features, but individual patients have only a single antisynthetase. Rare autoantibodies to certain translation factors may be associated with a similar syndrome. Anti-SRP is commonly associated with severe, acute, resistant myositis, whereas anti-Mi-2, the only MSA directed at a nuclear protein, is specifically associated with DM. Patients with anti-PM-Scl commonly have an overlap syndrome of PM/DM and SSc. Recent studies have recognized other antibodies in PM and DM, including antibody to endothelial cells, heat shock proteins, and, in a high proportion of patients, a 56-kd component of a ribonucleoprotein particle. The MSAs and their antigens are being characterized in detail. To date, data suggest similarity of predominant epitopes between different patients and a tendency toward conformational epitopes. It is not known if the recognized autoantibodies participate in tissue injury or pathogenetic processes, but production of the MSAs appears to be linked to etiologic factors and can be a clue to understanding the disease. Although these autoimmune responses are becoming better defined, the inciting events leading to generation of these responses and development of PM and DM remain unknown.
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PMID:Immune manifestations of inflammatory muscle disease. 785 26

HMGB1 is a non-histone nuclear protein that can serve as an alarmin to drive the pathogenesis of inflammatory and autoimmune disease. Although primarily located in the cell nucleus, HMGB1 can translocate to the cytoplasm, as well as the extracellular space, during cell activation and cell death; during activation, HMGB1 can undergo post-translational modifications. The activity of HMGB1 varies with the redox states of the cysteine residues, which are required for binding to TLR4. In addition to stimulating cells directly, HMGB1 can form immunostimulatory complexes with cytokines and other endogenous and exogenous factors. In the synovia of patients with rheumatoid arthritis, as well as animal models of this disease, extranuclear expression of HMGB1 is increased and blockade of HMGB1 expression attenuates disease in animal models. In systemic lupus erythematosus, HMGB1 can be a component of immune complexes containing anti-DNA because of its interaction with DNA. In myositis, expression of HMGB1 is enhanced in inflamed muscle and can perturb muscle function. Together, these findings indicate that HMGB1 might be an important mediator and biomarker in rheumatic diseases as well as a target of new therapy.
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PMID:HMGB1: a multifunctional alarmin driving autoimmune and inflammatory disease. 2229 56