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

We studied the immunologic correlates of disease activity and differences among subgroups of patients with idiopathic inflammatory myopathy by analysing phenotypic and activation marker expression on peripheral blood mononuclear cells (PBMC). Compared with controls, myositis patients with clinically active disease (n = 51) had significantly lower proportions of CD8+ cells and higher proportions of PBMC that expressed DR, CD3- DR, CD14- DR, interleukin-2 receptors, and the late T cell activation markers CD26 and TLiSA1. TLiSA1 expression, a marker for cytotoxic differentiation, correlated significantly with both clinical activity indices and serum levels of muscle-associated enzymes. In serial studies of seven patients, the proportion of PBMC expressing MHC class II antigen and late T cell activation markers decreased as myositis disease activity decreased, independent of type of therapy. Among the clinical subgroups, polymyositis (n = 21) and inclusion body myositis (n = 11) were virtually indistinguishable; dermatomyositis patients (n = 19) showed decreased proportions of CD3+DR+ and TLiSA1+ cells, and increased proportions of CD20+ and CD20+DR+ cells compared with the other two groups. Patients with autoantibodies to histidyl-tRNA synthetase (Jo-1 antigen, n = 11) had significantly lower proportions of CD3+ and CD4+ cells, lower CD4/CD8 ratios, and higher proportions of CD+ cells expressing CD20, compared with patients without anti-Jo-1 antibodies. These findings support the concept that activated lymphocytes, especially cells undergoing anamnestic responses and cytotoxic differentiation, are important in the pathogenesis of idiopathic myositis. Moreover, taken together with other studies, these data suggest that groups of patients segregated by clinical or autoantibody status have different mechanisms of systemic immune activation and immunopathology.
 ...
PMID:Lymphocyte activation markers in idiopathic myositis: changes with disease activity and differences among clinical and autoantibody subgroups. 216 21

The immunopathology of Chagas' disease was studied in the experimental model of chronic infection in C57BL/10JT or mice. Sublethal infection with Trypanosoma cruzi, Y strain, induced specific antibodies and a delayed hypersensitivity response to parasite antigens. Mice developed chronic chagasic myocarditis but not skeletal muscle myositis. Binding of T cells to infected heart tissue was investigated during short-term cocultivation of lymphocytes with heart cryostat sections. T cells from infected mice and from normal controls bound equally to myocardium and liver sections from both infected and normal mice. A search in depth was attempted with cells heavily tagged with 99mTc. Labeled T cells from chagasic mice bound to both normal and infected myocardium slices. 99mTc-labeled T cells from controls gave the same binding values. Glass-adherent spleen cells behaved identically to T cells. Prior treatment of the tissue with serum from chronically infected mice did not increase the number of binding cells. Peritoneal macrophages tagged with 99mTc-sulfur colloid also bound to infected myocardium slices. The binding of macrophages was not changed by pretreatment of infected tissue with anti-T, cruzi antibodies. In short, this work did not detect any population of T cells or macrophages which could bind specifically to infected heart tissue to initiate an autoreactive process.
 ...
PMID:Immunopathology of experimental Chagas' disease: binding of T cells to Trypanosoma cruzi-infected heart tissue. 222 30

The clinical features, laboratory tests, EMG and muscle biopsy findings are notably similar in many patients with primary and overlap polymyositis. Studies of the immunological abnormalities and immunopathology in both types of inflammatory skeletal muscle conditions are closely related. Thus, there can be little doubt that both primary and overlap myositis are part of the spectrum of autoimmune rheumatic disease. With the recent introduction of monoclonal antibodies that are capable of defining more precisely the cells in a myositis infiltrate, and the development of more refined in vitro tests to study effector cell populations, the precise mechanisms that cause muscle damage are much closer to being identified.
 ...
PMID:Myositis in other connective tissue disorders. 661 May 27

Among the main concerns regarding the current therapy for the inflammatory myopathies are a lack of adequate controlled trials, a lack of objective means to reliably measure muscle strength, lack of natural history data, consideration of polymyositis, dermatomyositis, and inclusion-body myositis as a homogeneous group of inflammatory myopathies, and reliance on nonspecific markers for determining prognosis and assessing response to therapies. Prednisone remains the drug of choice in treating these disorders, although a controlled trial has never been undertaken to study its efficacy. Among the steroid-sparing agents, azathioprine, methotrexate, cyclosporine, and chlorambucil are used with invariably low to moderate success. There are no results of controlled trials to indicate whether one of these drugs is superior to another. Intravenous immunoglobulin, which is very expensive, was shown in a controlled trial to be effective in steroid-resistant dermatomyositis not only in dramatically improving muscle strength and skin rash but also in resolving the underlying immunopathology. Controlled trials of intravenous immunoglobulin in patients with polymyositis and inclusion-body myositis are under way. Inclusion-body myositis has emerged as a common inflammatory myopathy that is predictably disabling and resistant to most therapies.
 ...
PMID:Current treatment of the inflammatory myopathies. 786 79

Asthma is a condition characterized by variable airflow obstruction, airway hyper-responsiveness (AHR) and airway inflammation which is usually, but not invariably, eosinophilic. Current thoughts on the pathogenesis of asthma are focused on the idea that it is caused by an inappropriate response of the specific immune system to harmless antigens, particularly allergens such as cat dander and house dust mite, that result in Th2-mediated chronic inflammation. However, the relationship between inflammation and asthma is complex, with no good correlation between the severity of inflammation, at least as measured by the number of eosinophils, and the severity of asthma. In addition, there are a number of conditions, such as eosinophilic bronchitis and allergic rhinitis, in which there is a Th2-mediated inflammatory response, but no asthma, as measured by variable airflow obstruction or AHR. Bronchoconstriction can also occur without obvious airway inflammation, and neutrophilic inflammation can in some cases be associated with asthma. When we compared the immunopathology of eosinophilic bronchitis and asthma, the only difference we observed was that, in asthma, the airway smooth muscle (ASM) was infiltrated by mast cells, suggesting that airway obstruction and AHR are due to an ASM mast cell myositis. This observation emphasizes that the features that characterize asthma, as opposed to bronchitis, are due to abnormalities in smooth muscle responsiveness, which could be intrinsic or acquired, and that inflammation is only relevant in that it leads to these abnormalities. It also emphasizes the importance of micro-localization as an organizing principle in physiological responses to airway inflammation. Thus, if inflammation is localized to the epithelium and lamina propria, then the symptoms of bronchitis (cough and mucus hypersecretion) result, and it is only if the ASM is involved -- for reasons that remain to be established -- that asthma occurs.
 ...
PMID:New insights into the relationship between airway inflammation and asthma. 1214 12

The inflammatory myopathies include dermatomyositis (DM), polymyositis (PM), and sporadic inclusion-body myositis (s-IBM). In DM, the main immune effector response appears to be humoral and directed against the microvasculature, whereas in both PM and s-IBM, cytotoxic CD8+ T cells and macrophages invade and eventually destroy nonnecrotic muscle fibers expressing major histocompatibility complex class I. The need for more specific and safer therapies in inflammatory myopathies has prompted researchers to better decipher the molecular events associated with inflammation and muscle fiber loss in these diseases. The complex specific migration of leukocyte subsets to target tissues requires a coordinated series of events, namely activation of leukocytes, adhesion to the vascular endothelium, and migration. Cell adhesion molecules (CAM) and chemokines play a major role in this multistep process. In addition, cytokines by stimulating CAM expression and orchestrating T-cell differentiation also influence the immune response. This review focuses on recent advances in defining the molecular events involved in leukocyte trafficking in inflammatory myopathies. Specific topics include a concise summary of clinical features, pathological findings and immunopathology observed in inflammatory myopathies, background information about cytokines, chemokines and cell adhesion molecules, and the expression of these molecules in inflammatory myopathies.
 ...
PMID:Cytokines, chemokines, and cell adhesion molecules in inflammatory myopathies. 1463 80

The idiopathic inflammatory myopathies (IIM) are systemic connective tissue diseases in which autoimmune pathology is suspected to promote chronic muscle inflammation and weakness. We have performed low to high resolution genotyping to characterize the allelic profiles of HLA-A, -B, -Cw, -DRB1, and -DQA1 loci in a large population of North American Caucasian patients with IIM representing the major clinicopathologic groups (n = 571). We confirmed that alleles of the 8.1 ancestral haplotype were important risk markers for the development of IIM, and a random forests classification analysis suggested that within this haplotype, HLA-B*0801, DRB1*0301 and/ or closely linked genes are the principal HLA risk factors. In addition, we identified several novel HLA factors associated distinctly with 1 or more clinicopathologic groups of IIM. The DQA1*0201 allele and associated peptide-binding motif (KLPLFHRL) were exclusive protective factors for the CD8+ T cell-mediated IIM forms of polymyositis (PM) and inclusion body myositis (IBM) (pc < 0.005). In contrast, HLA-A*68 alleles were significant risk factors for dermatomyositis (DM) (pc = 0.0021), a distinct clinical group thought to involve a humorally mediated immunopathology. While the DQA1*0301 allele was detected as a possible risk factor for IIM, PM, and DM patients (p < 0.05), DQA1*03 alleles were protective factors for IBM (pc = 0.0002). Myositis associated with malignancies was the most distinctive group of IIM wherein HLA Class I alleles were the only identifiable susceptibility factors and a shared HLA-Cw peptide-binding motif (AGSHTLQWM) conferred significant risk (pc = 0.019). Together, these data suggest that HLA susceptibility markers distinguish different myositis phenotypes with divergent pathogenetic mechanisms. These variations in associated HLA polymorphisms may reflect responses to unique environmental triggers resulting in the tissue pathospecificity and distinct clinicopathologic syndromes of the IIM.
 ...
PMID:Immunogenetic risk and protective factors for the idiopathic inflammatory myopathies: distinct HLA-A, -B, -Cw, -DRB1 and -DQA1 allelic profiles and motifs define clinicopathologic groups in caucasians. 1626 9

The entities encompassing the syndromes collectively known as myopathies and myositis are composed of numerous separate and distinct disorders with a vast spectrum of clinical signs, symptoms, immunopathology, genetic and environmental influences, as well as overall clinical outcome. Classification of the myositides (diseases of skeletal muscle) remains a rather controversial subject due to our lack of complete understanding of this divergent group of disorders. The mainstay of achieving diagnosis of a myopathy has until relatively recently been with a combination of clinical acumen, laboratory assessment, electromyography, and muscle biopsy. The use of modern high-resolution cross-sectional imaging studies is of particular value in confirming the physical findings and identifying suitable sites for biopsy. Imaging is fast becoming an established part of the overall evaluation of myopathies and myositis, helping to delineate the location and extent of the disease process, and it is being recognized as central to a prompt and accurate diagnosis in some cases. Although radiology has mainly been seen to have a subsidiary role in the diagnosis of myositides, newer imaging techniques following recent determined research interests have began to spark a renewed interest in the complex field of skeletal muscle imaging.
 ...
PMID:The myositides: the role of imaging in diagnosis and treatment. 2048 29

Dermatomyositis (DM) is an idiopathic inflammatory myopathy (IIM) characterized by an inflammatory infiltrate primarily affecting the skeletal muscle and skin. Most common and peculiar cutaneous lesions include Gottron's papules, Gottron's sign and heliotrope rash. Different DM subsets have been identified until now encompassing classic DM, amyopathic DM, hypomyopathic DM, post-myopathic DM, and DM sine dermatitis. Patients with DM have a higher incidence rate of malignancy than the normal population. In these patients cancer occurs in about 30% of cases with higher occurrence in men and in elderly people. Bohan and Peter's diagnostic criteria, proposed in 1975, have been widely accepted and used until now. In the last ten years muscle immunopathology, myositis specific autoantibodies testing, and the use of new techniques of muscle imaging such as contrast-enhanced ultrasound or Magnetic Resonance Imaging have been introduced in the diagnostic work-up of patients with DM leading to the development of new diagnostic criteria.
...
PMID:The clinical features, diagnosis and classification of dermatomyositis. 2446 10

The former classification of myositis based on the clinical phenotype and muscle histology is now changing. We started from the concept of "dermatopolymyositis" to the recognition of inclusion body myositis and more recently of immune mediated necrotizing myopathies. Furthermore, during the last 10 years, the routine access to myositis associated or specific auto-antibodies permitted to fine tune homogenous subgroups of myositis patients with common phenotype, immunopathology and prognosis. Using this approach, the polymyositis group has completely disappeared, the former patients now being reclassified as having and inclusion body myositis or an overlap syndrome such as the anti-synthetase syndrome. The different subgroups of myositis associated with their specific auto-antibodies are described here.
 ...
PMID:[Acquired inflammatory myopathies: interest of specific autoantibodies for their classification]. 2616 90


1 2 Next >>