Immunological features of polymyositis/dermatomyositis

We prepared RNA probes from cloned segments of human and murine enteroviruses (EVs) for in situ hybridization of skeletal muscle biopsies from patients with dermatomyositis (DM), polymyositis, other inflammatory myopathies, and noninflammatory muscle diseases, and from normal control subjects. A probe derived from Theiler's murine encephalomyelitis virus (TMEV) detected viral RNA within mononuclear cells of the interstitial connective tissue in 3 of 5 patients with adult-onset DM. None of these patients showed positive hybridization to probes derived from human EVs (poliovirus type 1 and Coxsackie virus B3) applied to subjacent sections of the same biopsies. The remaining 2 adult DM patients, 4 patients with childhood-onset DM, and 24 non-DM patients did not react with either TMEV or human enterovirus probes. Histochemical stains for esterase and immunoperoxidase stains for Mac-1 antigen in the 3 DM patients who reacted positively revealed positive cells in the same distribution as, but in far greater number than, those positive by in situ hybridization. Immunoperoxidase staining for HLA-DR antigens revealed positive cells in the same distribution and number as were seen with the TMEV probe. We conclude that an EV-like agent, more closely related to TMEV than to human EVs, may be associated with DM and that this agent is probably localized within muscle macrophages that express class II major histocompatibility complex antigens.

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“…Numerous studies suggest that muscle injury in these disorders is mediated by cellular immune mechanisms [2]. Pathological [8].…”

mentioning

confidence: 99%

“…The cause of dermatomyositis (DM) and polymyositis (PM), inflammatory myopathies that occur in both children and adults, is not known El}. Numerous studies suggest that muscle injury in these disorders is mediated by cellular immune mechanisms [2]. Pathological [8].…”

mentioning

confidence: 99%

Evidence for a novel picornavirus in human dermatomyositis

Rosenberg

Rotbart

Abzug

et al. 1989

Annals of Neurology

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“…Polymyositis (PM) and dermatomyositis (DM) are the two most common types of IIM in developed countries, presenting muscle weakness and inflammation [2,3]. PM and DM are usually categorized together since the disease progression and muscle lesions are the same, irrespective of whether skin lesions are presented [4]. Serological features and clinical manifestations such as myositis-specific auto-antibodies were also reported for both PM and DM in clinical studies [5,6].…”

Section: Introductionmentioning

confidence: 99%

Meta-Analysis of Polymyositis and Dermatomyositis Microarray Data Reveals Novel Genetic Biomarkers

Song

Kim

Hong

et al. 2019

Genes

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Polymyositis (PM) and dermatomyositis (DM) are both classified as idiopathic inflammatory myopathies. They share a few common characteristics such as inflammation and muscle weakness. Previous studies have indicated that these diseases present aspects of an auto-immune disorder; however, their exact pathogenesis is still unclear. In this study, three gene expression datasets (PM: 7, DM: 50, Control: 13) available in public databases were used to conduct meta-analysis. We then conducted expression quantitative trait loci analysis to detect the variant sites that may contribute to the pathogenesis of PM and DM. Six-hundred differentially expressed genes were identified in the meta-analysis (false discovery rate (FDR) < 0.01), among which 317 genes were up-regulated and 283 were down-regulated in the disease group compared with those in the healthy control group. The up-regulated genes were significantly enriched in interferon-signaling pathways in protein secretion, and/or in unfolded-protein response. We detected 10 single nucleotide polymorphisms (SNPs) which could potentially play key roles in driving the PM and DM. Along with previously reported genes, we identified 4 novel genes and 10 SNP-variant regions which could be used as candidates for potential drug targets or biomarkers for PM and DM.

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“…DM is distinguished from PM by a typical rash, usually red, scaly and plaque-like, over the knuckles, wrists, elbows, knees and ankle malleoli and violaceous lesions in the periorbital and trunk area.2 Most authors, however, consider DM and PM together since the disease course and muscle lesions are the same, whether skin lesions are present or not. 3 These diseases are of unknown aetiology and reltively rare but have been associated with a host of inciting agents, from infections4 to vaccines5 to malignancies' and involve a multitude of immunological abnormalities.7 The classification scheme popularized by Bohan et al 8'9 and modified by Whitaker4 appears in Table I. This review concentrates on types I, II, III and V.…”

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confidence: 99%