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)

High-dose intravenous immune globulin (IVIG) is emerging as a promising therapy for patients with inflammatory myopathies who have become unresponsive to, or cannot tolerate, conventional therapies. In a double-blind, placebo-controlled study, using objective criteria for improvement, IVIG demonstrated moderate to dramatic improvement in 75% of the patients with dermatomyositis. Preliminary results from a controlled study in inclusion-body myositis show that IVIG may also exert a mild benefit, but only in a small number of patients and in certain muscle groups. In some patients with polymyositis, IVIG is reported to be of benefit but controlled studies have not yet been completed. Immunocytochemical, immunological and in vitro studies on the patients' repeated muscle biopsies and follow-up sera showed that IVIG exerts its action in inflammatory myopathies by: (i) inhibiting myotoxic cytokines, such as TNF-alpha and IL-1; (ii) blockade of Fc receptors on endomysial macrophages interfering with Fc receptor-mediated phagocytosis; and (iii) inhibiting the uptake of C3 and intercepting the formation and deposition of membranolytic attack complex on the endomysial capillaries.
 ...
PMID:Clinical benefits and immunopathological correlates of intravenous immune globulin in the treatment of inflammatory myopathies. 862 45

Cytokines have been shown to be potent inducers of major histocompatibility complexes (MHC) class I and II as well as of cell adhesion molecules in muscle tissue cultures, indicating that cytokines may play a role in mediating muscle fiber damage in inflammatory myopathies. We found in 21 cases of autoimmune myositis various amounts of inflammatory cells expressing interleukin (IL)-1 alpha and -beta, IL-2, IL-4, tumor necrosis factor (TNF) -alpha and -beta, and interferon (IFN)-gamma and its receptor. Muscle fibers displayed enhanced expression of IL-1 alpha and -beta, IL-2, and TNF-alpha. Upregulation of cytokines was strongest at sites of cellular infiltration typical for the respective myositis subtype. There was no correlation between the cytokine expression and the grade of inflammation. To a lesser extent, cytokines were also present in Duchenne muscular dystrophy expressed by muscle fibers positive for TNF-alpha and by phagocytic mononuclear cells. Expression of cytokines by the muscle fiber may enable the muscle fiber to induce and mediate the process of autoimmunization and antigen-expression by itself without primary presence of inflammatory cells. Cytokine-expressing muscle fibers may enhance the cytolytic potential of cytotoxic cells and the muscle fiber may serve as source and target.
 ...
PMID:Cytokine expression profile in idiopathic inflammatory myopathies. 878 92

We present an additional case of focal myositis which, after surgical excision of the muscular mass, did not evolve to generalized polymyositis. To our knowledge immunological evaluations of this disease have never before been carried out. Immunohistochemical analysis of the muscular mass showed the presence of activated endothelial cells, CD4 and macrophage cells in the perivascular and endomysial areas, suggesting an immune-mediated mechanism of muscular damage. At the same time the normal distribution of the peripheral blood lymphocyte subpopulations and the normal levels of serum IL-1 beta, IL-6, TNF-alpha, soluble IL-2R and soluble CD8 underline the non-systemic nature of the disease.
 ...
PMID:Immunohistochemical analysis of an additional case of focal myositis. 883 51

The age-related acquisition of resistance to fatal Sindbis virus infection was examined using a molecularly cloned laboratory strain of the AR339 isolate designated TRSB. TRSB caused 100% mortality in mice up to 5 days of age. Resistance to fatal infection developed abruptly between 5 and 9 days of age. Lethal Sindbis virus infection of mice inoculated at 4 days of age was characterized by high levels of virus replication, induction of high levels of interferon-alpha/beta and TNF-alpha and severe thymic involution indicative of a systemic stress response. These changes correlated with predominantly noninflammatory lesions. In contrast, TRSB infection of older mice was characterized by survival, more limited virus replication, reduced cytokine induction, and the development of inflammatory responses leading to encephalitis, myositis, and myocarditis. Previous studies utilized infections of neonatal mice with TRSB and an attenuated mutant of TRSB to compare fatal and nonfatal Sindbis infection (Trgovcich et al., 1996. Virology 224, 73-83). The experiments reported here utilize mouse age at the time of infection to create conditions for examination of fatal and nonfatal TRSB infections. Both experiments suggest that fatal infection is associated with a shock-like syndrome and little or no inflammatory pathology, while survival is correlated with greatly reduced cytokine levels and inflammatory lesions.
 ...
PMID:TNFalpha, interferon, and stress response induction as a function of age-related susceptibility to fatal Sindbis virus infection of mice. 1054 7

Pathogenesis of autoimmune diseases like systemic lupus erythematosus (SLE) is unresolved. Dysregulation of programmed cell death is discussed as a pathogenetic factor. We have previously shown that increased in vitro apoptosis of cultured peripheral blood mononuclear cells (PBMC) is nonspecific for SLE. Importantly, however, in recent experiments with SLE PBMC from patients with infections and fever in vitro apoptosis was strongly accelerated. We therefore hypothesized that regulation of apoptosis might be disturbed in activated SLE lymphocytes. Thus, we generated phytohemagglutinine (PHA)/IL-2 stimulated lymphoblasts in vitro. These lymphoblasts readily undergo apoptosis after culture in cytokine-free medium, and can be rescued by addition of gammac-chain cytokines IL-2, -4, -7, or -15. In lymphoblasts from 60 SLE patients tested in comparison to lymphoblasts from normal donors cultured in parallel, we found significant hyporesponsiveness to gammac-chain cytokines in SLE cells. Minor differences were also seen in lymphoblasts from patients with other systemic autoimmunopathies (mixed connective tissue disease, vasculitis, n=49)and in lymphoblasts from patients with other autoimmune diseases (mainly rheumatoid or reactive arthritis, myositis, n=44). In patients with high erythrocyte sedimentation rate (> 25 mm/h), TNF-alpha (> 6.5 pg/ml) or IL-12 (> 4.7 pg/ml) serum levels or detectable IFN-gamma concentrations hyporesponsiveness to gammac-chain cytokines was even more pronounced in SLE lymphoblasts, but not in lymphoblasts from the other groups. Moreover, increased apoptosis was seen in lymphoblasts from SLE patients with decreased complement (C)4 or elevated dsDNA antibody levels. In conclusion, these data suggest that in SLE patients with increased inflammatory activity and/or Th1 dominance signaling through gammac-chain cytokine receptors is deteriorated, leading to facilitated apoptosis of activated lymphocytes and enlarged onflow of apoptotic material.
 ...
PMID:Hyporesponsiveness to gammac-chain cytokines in activated lymphocytes from patients with systemic lupus erythematosus leads to accelerated apoptosis. 1198 12

Juvenile dermatomyositis (JDM) is a multisystem disease characterized by acute and chronic lymphocytic inflammation of the skeletal muscle and skin. The disease is marked early in its course by the presence of a vasculopathy or vasculitis, and later by the development of calcinosis. Research has focused on the epidemiology, etiology, and pathogenesis of the disease with, until more recently, limited therapeutic interventions. This article highlights treatment regimens, both traditional and more recent interventions. Traditional treatment for JDM includes high dose corticosteroid treatment with additional agents used in resistant disease or children with unwarranted adverse effects. Traditional therapy begins with daily oral corticosteroids, with intravenous corticosteroids utilized in severe disease; however, recent data suggests that short-term use of intravenous corticosteroids will allow a short-term improvement in strength, with no long-term change in outcome. More recent investigations suggest that early intervention with additional immunomodulatory agents will allow for a faster recovery, with less medication and disease sequelae. Use of methotrexate as an agent early in the disease course is becoming common place. Methotrexate, in conjunction with oral corticosteroids, allows a rapid improvement in symptoms, and allows for a more rapid reduction in corticosteroid dose. Methotrexate is considered as a steroid sparing agent, whether oral or intravenous corticosteroids are used. Additional immunomodulatory agents include the use of cyclosporine with or without methotrexate. Intravenous immunoglobulin has been reported to have benefit in resistant disease. There are exciting new agents which have great potential in treating JDM. Many of these agents are termed biologics and are being tested in adult myositis and juvenile arthritis. These include tumor necrosis factor (TNF)-alpha inhibitors, such as a chimeric monoclonal antibody to TNF-alpha, and a recombinant soluble human TNF receptor (p75)-Fc fusion protein. Many other new biological agents are also being tested in myositis.
 ...
PMID:Juvenile dermatomyositis: recognition and treatment. 1199 36

Important points regarding DM and C-ADM are as follows: C-ADM is a working functional designation for patients having the skin-only and skin-predominant subsets of DM, amyopathic DM, and hypomyopathic DM. C-ADM seems to have approximately 10% the incidence of classic DM in whites and possibly a higher incidence in Asians. Some patients who present with C-ADM, with or without subclinical laboratory abnormalities, can slowly progress to develop symptomatic muscle weakness over a period of years, whereas others go for 10 to 20 years and longer without the appearance of muscle weakness. C-ADM patients are at risk for potentially life-threatening complications of classic DM, such as interstitial lung disease, which may occur in up to 10% of C-ADM patients. This risk seems to be even greater in some ethnic subgroups (e.g., Japanese). C-ADM patients may also be at increased risk for internal malignancy and until further studies are carried out to confirm the statistical significance of this association, all such patients should have a thorough evaluation for internal malignancy, identical to the approach currently used in classic DM patients. Dermatologists are in the best position initially to diagnose C-ADM patients and can contribute greatly to their overall management and quality of life. Ongoing vigilance is required, however, for complications that can arise in C-ADM patients including potentially fatal interstitial lung disease, internal malignancy, delayed onset of muscle weakness from myositis, and complications of systemic drug therapy. Topical therapy with broad-spectrum sunscreens, anti-inflammatories, and antipruritics should be maximized during the initial management of the cutaneous manifestations of either classic DM or C-ADM. Single-agent or combined aminoquinoline antimalarial therapy represents the safest initial form of systemic therapy for DM-specific skin disease occurring in any clinical setting; however, this approach tends to be less effective in general than for cutaneous LE. There is a theoretical rationale for and limited preliminary successful anecdotal experience with the use of anti-TNF-alpha therapy in refractory cases of classic DM and C-ADM. Cautious systematic clinical trials in this area should be considered.
 ...
PMID:Dermatomyositis: an overview of recent progress with emphasis on dermatologic aspects. 1217 Aug 74

The limitations associated with the different approaches into the pathogenesis of the IIM have resulted in incomplete knowledge of disease mechanisms in myositis. In most research, in which muscle tissue was used to study the different aspects of disease, biopsies with inflammatory infiltrates have been selected. Although inflammatory cell infiltrates are a characteristic feature of myositis, selecting patients with inflammatory cell infiltrates for investigations naturally introduces a selection bias. Only a few studies have been published on patients without inflammatory infiltrates but with muscle weakness, and few studies have included follow-up biopsies after different therapies. The heterogeneity of the population of patients with myositis is another limitation of the studies of pathogenic mechanisms. Although most studies classify patients according to the Bohan and Peter criteria [118, 119], some studies used histopathologic criteria [6], and only a few studies included characterization with myositis-specific autoantibodies. Because myositis-specific autoantibodies are often associated with certain clinical profiles, classification according to autoantibody profiles could be important to define differences in the pathogenesis of different phenotypes [3]. From available data on pathogenic mechanisms it is evident that cellular and humoral immune responses are involved in disease mechanisms of myositis, but whether there is a muscle-specific immune response cannot be answered by current studies. It is likely that other mechanisms are important for development of muscle weakness, including metabolic disturbances, and muscle weakness could be caused by different mechanisms in different IIM subsets or in patients in different phases of the disease. There could be early changes, which reversibly affect the metabolism, and later, irreversible changes, that could be dependent on muscle fiber damage and replacement of muscle tissue by connective tissue and fat. Current findings suggest that cytokines, which are produced in muscle tissue from different cell sources including inflammatory cells, endothelial cells, and muscle fibers, could affect muscle function. Careful follow-up studies, including the effect of therapies targeting different molecules on molecular expression in muscle tissue, are likely to increase our knowledge on disease mechanisms. A better understanding of which molecules and mechanisms affect muscle function is likely to lead to improved, less toxic therapies in patients with myositis. Many possible target molecules for blocking therapies, especially the proinflammatory cytokines IL-1 and TNF-alpha, have been identified and should be studied in appropriate clinical settings given the currently poor outcomes of many patients with IIM.
 ...
PMID:Possible pathogenic mechanisms in inflammatory myopathies. 1250 73

Tumor necrosis factor alpha neutralization seems a rational therapy for myositis because this proinflammatory cytokine has been implicated in the pathogenesis of this disorder. Until now, we have treated 2 patients with a chimeric anti-TNF-alpha monoclonal antibody (infliximab). Both patients demonstrated a marked and sustained subjective and objective improvement without the occurrence of any side effects. These preliminary results suggest that anti-TNF-alpha treatment with infliximab is a safe and rapidly effective therapy for myositis.
 ...
PMID:Successful treatment of dermatomyositis and polymyositis with anti-tumor-necrosis-factor-alpha: preliminary observations. 1282 6

Idiopathic inflammatory myopathy is a chronic inflammatory muscle disease characterized by mononuclear cell infiltration in the skeletal muscle. The infiltrated inflammatory cells express various cytokines and cytotoxic molecules. Chemokines are thought to contribute to the inflammatory cell migration into the muscle. We induced experimental autoimmune myositis (EAM) in SJL/J mice by immunization with rabbit myosin and CFA. In the affected muscles of EAM mice, CX3CL1 (fractalkine) was expressed on the infiltrated mononuclear cells and endothelial cells, and its corresponding receptor, CX3CR1, was expressed on the infiltrated CD4 and CD8 T cells and macrophages. Treatment of EAM mice with anti-CX3CL1 mAb significantly reduced the histopathological myositis score, the number of necrotic muscle fibers, and infiltration of CD4 and CD8 T cells and macrophages. Furthermore, treatment with anti-CX3CL1 mAb down-regulated the mRNA expression of TNF-alpha, IFN-gamma, and perforin in the muscles. Our results suggest that CX3CL1-CX3CR1 interaction plays an important role in inflammatory cell migration into the muscle tissue of EAM mice. The results also point to the potential therapeutic usefulness of CX3CL1 inhibition and/or blockade of CX3CL1-CX3CR1 interaction in idiopathic inflammatory myopathy.
 ...
PMID:Inhibition of CX3CL1 (fractalkine) improves experimental autoimmune myositis in SJL/J mice. 1627 59


1 2 Next >>