Amyloid deposits and inflammatory infiltrates in sporadic inclusion body myositis: the inflammatory egg comes before the degenerative chicken

Abstract Sporadic inclusion body myositis (sIBM) is the most frequently acquired myopathy in patients over 50 years of age. It is imperative that neurologists and rheumatologists recognize this disorder which may, through clinical and pathological similarities, mimic other myopathies, especially polymyositis. Whereas polymyositis responds to immunosuppressant drug therapy, sIBM responds poorly, if at all. Controversy reigns as to whether sIBM is primarily an inflammatory or a degenerative myopathy, the distinction being vitally important in terms of directing research for effective specific therapies. We review here the pros and the cons for the respective hypotheses. A possible scenario, which our experience leads us to favour, is that sIBM may start with inflammation within muscle. The rush of leukocytes attracted by chemokines and cytokines may induce fibre injury and HLA-I overexpression. If the protein degradation systems are overloaded (possibly due to genetic predisposition, particular HLA-I subtypes or ageing), amyloid and other protein deposits may appear within muscle fibres, reinforcing the myopathic process in a vicious circle.
Source: Acta Neuropathologica - Category: Neurology Source Type: research

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In this study we aimed to further evaluate the ability of US to differentiate between IBM and Polymyositis/Dermatomyositis (PM/DM) and neuromuscular disorders using two separate cohorts.
Source: Neuromuscular Disorders - Category: Neurology Authors: Source Type: research
Purpose of review The present review describes the interferon (IFN)-signature currently emerging as a tool for the diagnosis of idiopathic inflammatory myopathies (IIMs), and aims at presenting the interests and limitations of this recent tool for the clinics and the research. Recent findings Recent in-vivo and in-vitro transcriptomic studies have evidenced the involvement of IFNs in the pathogenesis of IIMs. A correlation between the IFN-signature and the clinical severity of IIMs has been established. Moreover, studies pointed out differences in the IFN-signature regarding the IIM subgroup (dermatomyositis, polymyos...
Source: Current Opinion in Rheumatology - Category: Rheumatology Tags: MYOSITIS AND MYOPATHIES: Edited by Andrea Doria, Anna Ghirardello, and Mariele Gatto Source Type: research
Purpose of review Idiopathic inflammatory myopathies (IIM) are rare diseases with heterogenous clinicopathological features. In recent years, new classification systems considering various combinations of clinical, serological, and pathological information have been proposed. This review summarizes recent clinicoseropathological development in major subgroups of IIM. Recent findings Considering clinicoseropathological features, IIM are suggestively classified into four major subgroups: dermatomyositis, immune-mediated necrotizing myopathy (IMNM), antisynthetase syndrome (ASS), and inclusion body myositis (IBM). Many h...
Source: Current Opinion in Neurology - Category: Neurology Tags: NEUROMUSCULAR DISEASE: Edited by Michio Hirano Source Type: research
CONCLUSIONS: Probably p62 immunostaining could help to distinguish PM patients that are going to become sIBM, but to date there has been no systematic study to clarify p62 utility in myositis. PMID: 31253480 [PubMed - as supplied by publisher]
Source: Medicina Clinica - Category: General Medicine Tags: Med Clin (Barc) Source Type: research
AbstractPolymyositis with mitochondrial pathology (PM-Mito) is a rare form of idiopathic inflammatory myopathy with no definite diagnostic criteria and similarities to both PM and sporadic inclusion body myositis (s-IBM). The aim of this study is to address the dilemma of whether PM-Mito is a subtype of inflammatory myopathy or represents a disease falling into the spectrum of s-IBM. Herein, we report four female patients diagnosed with PM-Mito, highlighting their rather atypical clinical and histopathological characteristics that seem to indicate a diagnosis away from s-IBM. Muscle weakness was rather proximal and symmetr...
Source: Rheumatology International - Category: Rheumatology Source Type: research
Osman K. Yilmaz1, Stefanie Haeberle1, Meifeng Zhang1, Marvin J. Fritzler2, Alexander H. Enk1 and Eva N. Hadaschik1,3* 1Department of Dermatology, University of Heidelberg, Heidelberg, Germany 2Mitogen Advanced Diagnostics Laboratory, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada 3Department of Dermatology, University Hospital of Essen, Essen, Germany Due to a missense mutation in the Foxp3 gene, scurfy mice are deficient in functional regulatory T cells (Treg). The consequent loss of peripheral tolerance manifests itself by fatal autoimmune mediated multi-organ disease. Previous studies...
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research
The objectives of our study were to determine the sensitivity and specificity of anti-NT5c1A for sIBM, demonstrate demographic, clinical and serological predictors for anti-NT5c1A positivity and determine if anti-nuclear antibody (ANA) indirect immunofluorescence (IIF) staining on HEp-2 cells is a reliable screening method for anti-NT5c1A. Methods: Sera from sIBM patients and controls were stored at −80°C until required for analysis. IgG antibodies to NT5c1A were detected by an addressable laser bead immunoassay (ALBIA) using a full-length human recombinant protein. Autoantibodies to other autoimmune myopathy an...
Source: Frontiers in Immunology - Category: Allergy & Immunology Source Type: research
Idiopathic inflammatory myopathies are a group of autoimmune diseases that are characterized by muscle inflammation resulting in elevated muscle enzyme release and distinctive biopsy findings. This group of conditions includes polymyositis, dermatomyositis, inclusion body myositis, and necrotizing autoimmune myopathy. Although they have many similarities, the inflammatory myopathies differ in their clinical, pathological, and treatment realms. Extramuscular manifestations may involve many organs that include the skin, joints, heart, lungs, and gastrointestinal tract. Cardiovascular involvement is one of the leading causes ...
Source: Cardiology in Review - Category: Cardiology Tags: Review Articles Source Type: research
Conclusion 18F-FDG PET/CT does not appear to be useful in cancer screening for AIM patients compared with conventional screening and carries potential harms associated with follow-up investigations. The risk of cancer in AIM differs by myositis-specific antibodies-defined subsets and cancer screening is likely to be indicated only in high-risk patients, particularly DM. These results, replicated in larger, multicentered studies, may carry significant consequences for optimal management of AIM and health resource utilization.
Source: Nuclear Medicine Communications - Category: Nuclear Medicine Tags: ORIGINAL ARTICLES Source Type: research
Conclusions Normal muscle contains a considerable number of macrophages and T-lymphocytes. Muscle biopsy is likely to detect inflammatory changes in patients with myalgia or hyperCKemia only if pathologic EMG findings are present.
Source: Neurology Neuroimmunology and Neuroinflammation - Category: Neurology Authors: Tags: Autoimmune diseases, Muscle disease, EMG Article Source Type: research
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