Idiopathic inflammatory myopathy (IIM) is a rare group of autoimmune diseases, characterized by chronic muscle weakness, muscle fatigue and infiltration of single nuclear cells in skeletal muscle. Its subtypes include dermatomyositis (DM), polymyositis (PM), inclusion body myositis (IBM) and immune-mediated necrotizing myositis (IMNM), and the most common subtypes are DM and PM. PM is an autoimmune disease mainly manifested by muscle damage. When the skin is involved, it is called DM. The incidence of IIM was relatively low, which was 1.16-19 per million people/year, but the mortality was high and the prognosis was poor. The pathogenesis of IIM is still unclear. Previous studies suggest that both immune and non-immune mechanisms are involved in its pathogenesis, especially cellular and humoral immunity. In recent years, researchers have conducted a number of studies on the pathogenesis of IIM, especially in the study of DM/PM with the application of high-throughput biometrics. Epigenetics is a discipline that refers to the genetic phenomena of DNA methylation spectrum, chromatin structure state and gene expression spectrum transferred between cells without any changes in DNA sequence, including DNA methylation, chromatin modification and non-coding RNA changes. A large number of studies have shown that epigenetic modification plays an important role in many diseases, especially in cancer. Recent studies have also found a series of epigenetic markers related to the occurrence and development of DM/PM, mainly in the aspect of non-coding RNA changes, such as miR-10a, miR-206, etc. And there has also been some research on DNA methylation. However, no studies have been reported on whether chromatin modification is involved in the pathogenesis of DM/PM. The pathogenesis of DM/PM is complex and diverse. With the development of research, certain microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) may become biological markers for the early diagnosis of DM/PM. Therefore, this paper mainly expounds the research progress of the biomarkers of DM/PM from the aspect of epigenetics.
Biomarkers ; Dermatomyositis ; Humans ; MicroRNAs ; Muscle, Skeletal ; Polymyositis

Dermatomyositis ; classification ; Humans ; Myositis ; classification ; Polymyositis ; classification

Dematomyositis is an inflammatory cutaneo-muscular disease of unknown etiology, characterized by symmetrical proximal muscle weakness and typical dermatologic manifestation. Association with systemic maligmancy has been reported in many literatures, but the relationship of dermatomyositis to internal malignancy remains controversial. In Korea, several cases of dermatomyositis or polymyositis associated with malignant neoplasm were reported. Dermatomyositis or polymyositis associated with primary hepatoma has not been reported, Recently authors experienced a patient with dermatomyositis associated with primary hepatoma, and present the case with review of literatures. This may be the first report in Korea.
Carcinoma, Hepatocellular* ; Dermatomyositis ; Humans ; Korea ; Muscle Weakness ; Polymyositis

Objective: To investigate the expression of toll-like receptor (TLR)-2, 4 and 9 in idiopathic inflammatory myopathies (IIMs). Methods: The expression of TLR-2, 4 and 9 was measured by real-time RT-PCR and immunohistochemical stain (IHS) from muscle tissues in patients with IIMs and controls. Results: The expression levels of TLR-2, 4 and 9 in IIMs were significantly higher than controls. TLR-2, 4 and 9 were mainly expressed on sarcolemma of muscle fibers, perimysial vascular endothelium and infiltrating inflammatory cells in dermatomyositis, whereas, they were mainly expressed on sarcolemma of muscle fibers, destructed muscle fibers, and enodmysial infiltrating inflammatory cells in polymyositis. Conclusion: TLR-2, 4 and 9 were highly expressed in muscle tissue of IIMs. These results suggest that TLR-2, 4 and 9 play a role in pathogenesis of IIMs.
Dermatomyositis ; Endothelium, Vascular ; Humans ; Myositis* ; Polymyositis ; Sarcolemma ; Toll-Like Receptors*

No abstract available.
Hepatitis* ; Polymyositis*

Extrapulmonary manifestations of Mycoplasma pneumoniae infection are not uncommon and involvement of every organ system has been reported. However, association of inflammatory myositis with M. pneumoniae infection is rare. Here, we describe a patient who developed polymyositis associated with mycoplasma infection, who was treated successfully with glucocorticoid, intravenous immunoglobulin, and methotrexate.
Adolescent* ; Dermatomyositis* ; Female* ; Humans ; Immunoglobulins ; Methotrexate ; Mycoplasma Infections ; Mycoplasma pneumoniae* ; Mycoplasma* ; Myositis ; Pneumonia ; Pneumonia, Mycoplasma* ; Polymyositis

OBJECTIVE: The purpose of the study is to describe the magnetic resonance imaging (MRI) findings and to investigate useful sequences of MRI in inflammatory myopathies. A third goal is to correlate MRI findings with the grade of histopathologic severity. METHODS: Sixteen patients (13 women, 3 men), aged 21-74 years (median age of 49) with inflammatory myositis (examined with both MRI and muscle biopsy) were studied. Ten patients were diagnosed with polymyositis and 6 with dermatomyositis. Conventional T1-weighted (SE 366/12) and T2-weighted (SE 4766/90) fast spin-echo and fat-suppressed T1-weighted MR images with contrast enhancement (FSAT T1 CE) were obtained. Ratios between the signal intensities of a muscle and the signal intensities of subcutaneous fat in the same tomographic sections were calculated to objectively represent the degree of signal intensities. Semi-quantitative grading of severities in muscle biopsy specimen was examined based on invasion of inflammatory cells and necrosis, degeneration and regeneration of muscle fiber by a neuromuscular pathologist. RESULTS: FSAT T1 CE could objectively describe the severity of involvement in inflammatory myopathies. The quadriceps muscle group, especially the vastus muscle tended to be most severely and frequently involved in inflammatory myositis with FSAT T1 CE (statistically insignificant). The vastus intermedius muscle was more severely involved in dermatomyositis than polymyositis. The signal intensity of abnormal muscle sampled by biopsy correlated positively with the grade of muscle biopsy. CONCLUSION: MRI shows promise in identifying pathologic muscle in patients suspected of having one of the inflammatory myopathies. The degree of signal intensity on MRI may reflect the severity of grade in muscle biopsy.
Biopsy ; Dermatomyositis ; Female ; Humans ; Magnetic Resonance Imaging* ; Myositis* ; Necrosis ; Polymyositis ; Quadriceps Muscle ; Regeneration ; Subcutaneous Fat

OBJECTIVE: To assess the 10-year cumulative survival outcome of polymyositis (PM) and dermatomyositis (DM) as well as the factors associated with the the outcome. METHODS: Eighty five patients with PM and twenty one patients with DM were diagnosed at our university medical center between 1997 and 2007. Thirty six patients with PM and 13 patients with DM were followed up until death or until the end of January, 2008. Gender, age, AST, ALT, CPK, LDH, ESR, CRP, aldolase, drugs of therapy, combined ILD, and cancer, and duration of remission after therapy were assessed as prognostic factors of death by the Kaplan-Meier curve and Cox regression model. RESULTS: The respective 10-year survival rate for PM and DM was 80.8% (95% confidence interval (CI): 73.3~87.2) and 55.9% (95% CI: 40.7~71.1), respectively. The median survival for PM and DM was 11.3 years (95% CI: 9.8~12.9) and 7.0 years (95% CI: 3.6~10.5), respectively. Compared to DM patients, the subjects with PM had a 167.26 fold (95% CI: 7.59~3683.19) combined ILD adjusted risk of mortality (p<0.05) and no other individual factor reached significance as a predictor of death. However, cancer had a hazard ratio (HR) of 17.00 (95% CI: 1.06~281.79) and 2.45 (95% CI: 0.78~12.45) for death in the PM and DM group, respectively. CONCLUSION: According to an analysis of the survival and its prognostic factors in patients with PM and DM, ILD is a risk factor for mortality in PM and cancer was risk factor for mortality in both PM and DM.
Academic Medical Centers ; Dermatomyositis ; Fructose-Bisphosphate Aldolase ; Humans ; Myositis ; Polymyositis ; Risk Factors ; Survival Rate

Poikilodermatomyositis is a variant of dermatomyositis which is characterized by polymyositis associated with mottled dark brownish pigmentation, seattered atrophic patch and telangiectasia of the skin. Poikiloderma usually occurs in patient with long standing dermatomyositis. The authors observed a case of typical poikilodermatomyositis in a 40-year-old male. Skin examination revealed dark brownish pigmentation, telangiectasia and whitish atrophic patches on entire body. Muscles of shoulder girdle were markedly wasted. Muscle weakness was so severe that he could not elevate his arm above shoulder level. He also had difficulty in going up stairs. Histopathologic findings of the skin were similar to those of poikiloderma vasculare atrophicans. Light microscopic and eIectronmicroscopic examination of muscle reveaIed myositis.
Adult ; Arm ; Dermatomyositis ; Humans ; Male ; Muscle Weakness ; Muscles ; Myositis ; Pigmentation ; Polymyositis ; Shoulder ; Skin ; Telangiectasis

Many rheumatic diseases may involve any organ system of the body including the skin. Proper understanding of rheumatic skin disease is necessary for making a diagnosis. In addition, there are important relationships existing between the cutaneous and systemic manifestations of rheumatic diseases. In management of these diseases, the interdisciplinary approach could generate better results. Among rheumatic diseases, the cutaneous manifestations of three major rheumatic diseases such as lupus erythematosus (LE), dermatomyositis (DM)/polymyositis and scleroderma/systemic sclerosis (SSc) will all be reviewed.
Dermatomyositis ; Lupus Erythematosus, Systemic ; Rheumatic Diseases ; Polymyositis ; Scleroderma, Systemic ; Skin ; Skin Diseases