Physical exercise for dermatomyositis and polymyositis: a systematic review and meta-analysis.

Trials regarding physical exercise in dermatomyositis (DM) and polymyositis (PM) are heterogeneous. We aimed to summarize and critically analyze the available evidence to support the hypothesis that exercise is safe and improves strength and aerobic capacity. We performed a systematic review of clinical trials regarding physical exercise in dermatomyositis and polymyositis, without time restriction. We included studies from MEDLINE, EMBASE, SciELO, and Web of Science, published in English, Portuguese, or Spanish, and reporting outcomes related to safety, muscle performance, or aerobic capacity. The certainty of evidence was evaluated in accordance with the GRADE methodology. Meta-analysis was carried using pooled standardized mean differences (SMD) with 95% confidence interval as effect measure. We included 19 studies and 298 patients. The certainty of evidence was downgraded due to unbalanced confounding variables. The meta-analysis demonstrated improvements in strength (SMD [95% CI] = 0.61 [0.37-0.85], P < .00001) and aerobic capacity (SMD [95% CI] = 0.82 [0.29-1.34], P = .002), with no difference in creatine phosphokinase levels (SMD [95% CI] = - 0.23 [- 0.5-0.03], P = .08) after the interventions. No exacerbation was reported, and results were favorable in all stages of disease and ages, but might be different in the future with new classification criteria for PM and the inclusion of other idiopathic inflammatory myopathies. Novel approaches such as blood flow restriction training and aquatic plyometric exercises were promising. Physical exercise in DM/PM patients of all ages is probably safe and moderately improves muscle strength and aerobic capacity.

Antibody Therapies in Autoimmune Inflammatory Myopathies: Promising Treatment Options.

Inflammatory myopathies, including polymyositis (PM), dermatomyositis (DM), inclusion body myositis (IBM), necrotizing myopathy (NM), antisynthetase syndrome (ASS) and overlap myositis (OM), in short myositis, are rare diseases. All forms of myositis have progressive muscle weakness in common, with each subtype characterized by different autoantibody profiles, histological findings and extramuscular manifestations. Due to better understanding of the pathogenesis of the muscle inflammation in myositis, new molecular pathways for targeted therapy have been discovered. Current therapies aim at different components of the innate or the adaptive immune response. Additionally, non-inflammatory mechanisms in myositis have come into focus as possible treatment targets. The use of therapeutical antibodies in myositis has been examined in various clinical studies, several of them randomized controlled ones: Depletion of B-cells by rituximab has been established as treatment of refractory myositis. IVIG, an antibody therapy in the wider sense, has now been licensed for DM following a recent positive clinical trial. Negative study results were reported in randomized trials with infliximab, sifalimumab and bimagrumab. Studies on basiliximab and eculizumab are currently underway, and are expected to yield results in a couple of years. Despite some promising results of clinical studies with antibody therapy in myositis, further research is crucial to optimize the treatment for this debilitating disease and to find treatment alternatives for treatment-refractory patients.

Chronic graft-versus-host disease presenting as acute polymyositis: A case series and systematic review.

Chronic graft-versus-host disease (cGvHD) remains a significant complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Commonly targeted organs are skin, eyes, mouth, gastrointestinal tract, and liver. Muscular involvement and presentation as acute polymyositis (APM) remain a rare manifestation of cGvHD. We present a case series of three patients who presented with APM as a sole presentation of cGvHD and were treated successfully with corticosteroids and ruxolitinib. We also conducted a systematic review including 72 patients to summarize current literature regarding APM associated with cGvHD after allo-HSCT. The estimated incidence of cGvHD-associated APM is up to 3.4%, with a median time to onset of 1.6 years post-allo-HSCT. Most cases (85%) presented with myalgia and progressive bilateral proximal muscle weakness with elevated creatine kinase and/or aldolase. Over half of the patients had a prior history of acute GvHD. Isolated APM presenting without other clinical manifestations of cGvHD was rare. Biopsy of affected muscles usually shows characteristic myonecrosis, which remains the gold standard for diagnosis. Most cases respond to systemic steroids and immunosuppressive therapy. However, refractory cases remain challenging to treat and can cause significant morbidity and mortality. Ruxolitinib appears to be an effective therapy in this setting.

Replacement and Immunomodulatory Activities of 20% Subcutaneous Immunoglobulin Treatment: A Single-Center Retrospective Study in Autoimmune Myositis and CVID Patients.

Background: Immunoglobulin (Ig) replacement therapy represents a life-saving treatment in primary antibody deficiencies. The introduction of subcutaneous Ig (SCIg) administration brings a major improvement in quality of life for patients, compared to the traditional intravenous administration. In recent years, an additional role has been proposed for Ig therapy for various inflammatory and immune-mediated diseases. Consequently, the use of SCIg has expanded from immunodeficiencies to immune-mediated diseases, such as polymyositis (PM) and dermatomyositis (DM). Given the rarity of these conditions, it is still difficult to evaluate the real impact of SCIg treatment on PM and DM, and additional data are constantly required on this topic, particularly for long-term treatments in real-life settings. Aim: This study aimed to increase the knowledge about the anti-inflammatory and immunomodulatory effects of SCIg treatment for myositis. To this aim, a long-term evaluation of the effectiveness of 20% human SCIg treatment (20% SCIg, Hizentra®, CSL Behring) was carried out in patients with PM/DM in care at our Center. In addition, an evaluation of the 20% SCIg therapy in CVID patients was provided. This analysis, beside adding knowledge about the use of SCIg therapy in this real-life setting, was intended as a term of comparison, regarding the safety profile. Results: Results support the beneficial effect and tolerability of long-term 20% SCIg therapy in PM/DM patients, reporting a significant improvement in creatine kinase levels, muscle strength, skin conditions, dysphagia, disease activity (MITAX score) and disability (HAQ-DI score). None of the patients reported systemic reactions. The duration of the reported local reactions was a few hours in 80% of the patients, and all resolved spontaneously. CVID patients reported an improvement in all the considered effectiveness parameters at the end of 20% SCIg therapy. The frequency of the adverse events reported by PM/DM patients was not different from what reported in CVID patients, where the use of SCIg therapy is more consolidated. Conclusions: This study suggests that 20% SCIg treatment represents a viable and safe treatment for PM/DM patients and a valid therapeutic alternative to IVIg, with important advantages for patients' quality of life.

COVID-19 and myositis - unique challenges for patients.

OBJECTIVE: The COVID-19 pandemic and the subsequent effects on healthcare systems is having a significant effect on the management of long-term autoimmune conditions. The aim of this study was to assess the problems faced by patients with idiopathic inflammatory myopathies (IIM). METHODS: An anonymized eSurvey was carried out with a focus on effects on disease control, continuity of medical care, drug procurance and prevalent fears in the patient population. RESULTS: Of the 608 participants (81.1% female, median (s.d.) age 57 (13.9) years), dermatomyositis was the most frequent subtype (247, 40.6%). Patients reported health-related problems attributable to the COVID-19 pandemic (n = 195, 32.1%); specifically 102 (52.3%) required increase in medicines, and 35 (18%) required hospitalization for disease-related complications. Over half (52.7%) of the surveyed patients were receiving glucocorticoids and/or had underlying cardiovascular risk factors (53.8%), placing them at higher risk for severe COVID-19. Almost one in four patients faced hurdles in procuring medicines. Physiotherapy, critical in the management of IIM, was disrupted in 214 (35.2%). One quarter (159, 26.1%) experienced difficulty in contacting their specialist, and 30 (4.9%) were unable to do so. Most (69.6%) were supportive of the increased use of remote consultations to maintain continuity of medical care during the pandemic. CONCLUSION: This large descriptive study suggests that the COVID-19 pandemic has incurred a detrimental effect on continuity of medical care for many patients with IIM. There is concern that delays and omissions in clinical care may potentially translate to poorer outcomes in the future.

Mortality in Patients with Polymyositis and Dermatomyositis in an Israeli Population.

BACKGROUND: The reported mortality rates of patients with polymyositis and dermatomyositis are highly variable worldwide. The excess mortality of patients with polymyositis/dermatomyositis has not been evaluated in an Israeli population. OBJECTIVES: To investigate the overall mortality in a large and well-established cohort of patients with polymyositis/dermatomyositis as compared to the mortality expected in the matched general population in a tertiary medical center. METHODS: In this retrospective cohort study, the mortality of 166 patients with polymyositis/dermatomyositis was compared to age- and sex-matched control subjects in the general population. All-cause standardized mortality ratios (SMRs) were estimated. RESULTS: Overall, 47 (28.3%) deaths were observed among patients with polymyositis/dermatomyositis during a mean follow-up period of 5.8 ± 4.8 years, which was 7 times higher than in the control group (SMR 7.4, 95% confidence interval [95%CI] 5.5-9.8). The SMRs were comparable in patents with polymyositis (7.7, 95%CI 4.8-12.3) and dermatomyositis (7.2, 95%CI 5.0-10.3). The 1-, 5-, 10-, and 15-year overall survival rates were 90.0%, 82.8%, 51.5%, and 26.1%, respectively, in patients with polymyositis, and 80.3%, 59.6%, 40.0%, and 17.1%, respectively, in patients with dermatomyositis. CONCLUSIONS: The overall mortality among Israeli patients with polymyositis/dermatomyositis is 7.4 times greater than for the general population. Although long-term mortality was comparable between patients with dermatomyositis and polymyositis, patients in the former group died at a notably earlier stage.

Patient-reported dermatomyositis and polymyositis flare symptoms are associated with disability, productivity loss, and health care resource use.

BACKGROUND: Flare activity or worsening symptoms are not well defined for myositis. OBJECTIVES: To (a) characterize dermatomyositis (DM) and polymyositis (PM) flares from the patient perspective and (b) report the corresponding disability and rate of unplanned medical encounters. METHODS: Online survey data were collected from volunteer patients from The Myositis Association and Johns Hopkins Myositis Center. Flare frequency; Health Assessment Questionnaire Disability Index (HAQ-DI), HAQ-Pain Index, Work Productivity and Activity Impairment (WPAI) scales; emergency department/urgent care (ED/UC) visits; and hospital admissions during the past year were examined. RESULTS: 564 individuals with selfreported diagnoses of DM/PM were surveyed between December 2017 and May 2018. Recall of symptom flares was reported by 524 respondents (78.1% were female, mean age of 55 years). Among the respondents, 378 (72.1%) reported ≥ 1 flare in the past year. The pattern of flare frequency was similar for DM and PM respondents. The most common symptoms were muscle weakness (83%), extreme fatigue (78%), and muscle pain/discomfort (64%). Increasing flare frequency was associated with significantly (P < 0.01) greater mean HAQ-DI and HAQ-Pain scores, myositis-related ED/UC visits, hospital admissions, WPAI work productivity loss (among those employed), and WPAI nonwork activity impairment. CONCLUSIONS: DM/PM-related flares are common with exacerbations of muscle weakness and fatigue being the most common flare symptoms. Flare frequency was associated with greater disability, pain, work productivity loss, nonwork activity impairment, and increased ED/UC utilization. Higher frequency of patient-reported flares may serve as a marker of worsening physical functioning and intensifying health care needs and, therefore, suggests their importance in the clinical assessment of patients with DM/PM. DISCLOSURES: This study was supported by Mallinckrodt Pharmaceuticals (Bedminster, NJ) via grants to Vedanta Research and The Myositis Association. Christopher-Stine has received compensation from previous Mallinckrodt Advisory Board meetings, unrelated to this subject matter. Wan is an employee of Mallinckrodt Pharmaceuticals and is a stockholder of the company. Reed and Bostic received grant support from Mallinckrodt Pharmaceuticals for data collection and analysis. McGowan is an employee of The Myositis Foundation, which received grant funding to support study data collection. Kelly has no conflicts to disclose. This study was presented, in part or full, at the 2019 Annual American College of Rheumatology and Association of Rheumatology Professional Meeting (November 8-13, 2018; Atlanta, GA) and at the Third Global Conference on Myositis (March 27, 2019; Berlin, Germany).

A systematic review of internet-based information on dermatomyositis and polymyositis.

AIM: Patients with rheumatic diseases are increasingly using internet-based information to inform healthcare utilization and make treatment decisions. Our aim was to assess the readability and quality of internet-based information on dermatomyositis (DM) and polymyositis (PM). METHOD: Key words "Dermatomyositis" and "Polymyositis" were searched on 3 commonly used search engines (Google, Yahoo and Bing). The first 3 pages (~30) of search results were examined from each search engine. Readability of information was assessed using 4 readability formulae (Flesch Reading Ease Score, Flesch-Kincaid Grade Level, the Simplified Measure of Gobbledygook index, the Coleman-Liau index). Quality of information was assessed using the DISCERN tool, Journal of The American Medical Association (JAMA) benchmark criteria and Health on The Net Code (HoN code). We also examined Google Trends® data to determine if there were obvious temporal search patterns. RESULTS: Thirty-two websites were included in the study after duplicates were removed and exclusion criteria were applied. The overall quality was low including DISCERN with a median overall score of 38/80 (interquartile range 12.25), only 4/32 (13%) websites fulfilled all 4 JAMA benchmark criteria, and 9/32 (28%) had HoN code. Readability of information was assessed using 4 readability formulae (Flesch Reading Ease Score, Flesch-Kincaid Grade Level, the Simplified Measure of Gobbledygook index, the Coleman-Liau index. There was no obvious temporal trend in searches on analysis of Google Trends® data. CONCLUSION: The overall quality and readability of internet-based information relating to DM and PM is poor. Patients require appropriate information of high quality and readability throughout the course of their disease in order to make informed decisions on their condition including treatment.

[Idiopathic Inflammatory Myopathies]. / Idiopathische inflammatorische Myopathien.

Myositis is a rare and an extremely heterogeneous autoimmune disease, that causes muscle weakness. Currently, "idiopathic inflammatory myopathies (IIM)" is the preferred umbrella-term used to describe the disease complexity within individuals. IIM include dermatomyositis, polymyositis, inclusion body myositis, autoimmune necrotizing myopathy, overlap myositis and antisynthetase syndrome. Research activity concerning myositis was very intense over the past ten years and led to new diagnostic approach as well as to novel therapeutic strategies. Correct classification is the key for successful management. One single treatment regime for every possible organ involvement in all different forms of IIM is still not existing.

Risk of thrombotic events after inpatient intravenous immunoglobulin or plasma exchange for neurologic disease: A case-crossover study.

INTRODUCTION: Our aim in this study was to determine whether intravenous immunoglobulin (IVIg) or plasma exchange (PLEx) for treatment of neurologic disease is a trigger for thrombotic events. METHODS: Using administrative data from 2005 to 2014, we identified index admissions for thrombotic events. We performed case-crossover analyses for these admissions with previous admissions for neurologic disease with IVIg or PLEx using exposure periods of between 7 and 120 days. RESULTS: We identified 1.9 million admissions for venous thrombosis embolism, myocardial infarction, or acute ischemic stroke. The odds ratio for venous thrombosis embolism within a 30-day window after exposure to IVIg was 3.33 (1.34-8.30, P = .0097) and for PLEx was 4.29 (1.88-9.76, P = .0005). Myocardial infarction and acute ischemic stroke admissions were not associated with exposure to either therapy. DISCUSSION: Patients admitted for venous thrombosis embolism (but not acute ischemic stroke or myocardial infarction) were more likely exposed to either IVIg or PLEx during previous admission for neurologic disease.

Inpatient burden and resource utilization of polymyositis and dermatomyositis: A 10-year Study of National Inpatient Sample.

OBJECTIVES: To characterize inpatient prevalence and resource utilization of patients with polymyositis (PM) and dermatomyositis (DM). METHODS: Patients with PM/DM were identified from the Nationwide Inpatient Sample (NIS) database from the year 2005 to 2014 using ICD-9 diagnostic codes. The primary outcome of this study was inpatient prevalence of PM/DM in the United States across the span of 10 years. Secondary outcomes included reason for hospitalization, inpatient mortality, morbidity, hospital length of stay (LOS), utilization of specialized procedures/tests and expenditures. A cohort of patients without PM/DM was also identified from the same database to serve as comparators. Multivariate regression analysis was used to adjust for age, sex, ethnicity, comorbidities and hospital characteristics. RESULTS: A total of 160,528 admissions of patients with a diagnosis of PM/DM occurred in the study period, corresponding to the inpatient prevalence of 41.9 cases per 100,000 discharges. During admission, patients with PM/DM died more frequently than patients without PM/DM with an adjusted odds ratio (aOR) of 2.22 (P<0.01). A significantly higher inpatient morbidity among patients with PM/DM was also observed as indicated by a significantly higher risk of shock (aOR 2.33; P<0.01), acute kidney injury (aOR 1.12; P<0.01), multi-organ failure (aOR 1.83; P<0.01) and need for admission to intensive care unit (aOR 1.94; P<0.01). Patients in the PM/DM had an average of 1.7 more days of LOS (P<0.01). The mean hospital costs and total hospitalization charges for patients with PM/DM were significantly higher than patients without PM/DM with additional adjusted mean of $4,217 and $13,531, respectively, in the multivariate model. Patients with PM/DM underwent computerized tomography scan (aOR 1.90; P<0.01), magnetic resonance imaging (aOR 1.68; P<0.01) and angiography (aOR 1.15; P<0.01) more often than comparators. CONCLUSIONS: Inpatient prevalence of PM/DM was higher than what would be expected from the overall incidence. Hospitalizations of patients with PM/DM were associated with significantly higher rate of mortality, morbidity and resource utilization.

Guidelines of the Brazilian Society of Rheumatology for the treatment of systemic autoimmune myopathies.

BACKGROUND: Recommendations of the Myopathy Committee of the Brazilian Society of Rheumatology for the management and therapy of systemic autoimmune myopathies (SAM). MAIN BODY: The review of the literature was done in the search for the Medline (PubMed), Embase and Cochrane databases including studies published until June 2018. The Prisma was used for the systematic review and the articles were evaluated according to the levels of Oxford evidence. Ten recommendations were developed addressing the management and therapy of systemic autoimmune myopathies. CONCLUSIONS: Robust data to guide the therapeutic process are scarce. Although not proven effective in controlled clinical trials, glucocorticoid represents first-line drugs in the treatment of SAM. Intravenous immunoglobulin is considered in induction for refractory cases of SAM or when immunosuppressive drugs are contra-indicated. Consideration should be given to the early introduction of immunosuppressive drugs. There is no specific period determined for the suspension of glucocorticoid and immunosuppressive drugs when individually evaluating patients with SAM. A key component for treatment in an early rehabilitation program is the inclusion of strength-building and aerobic exercises, in addition to a rigorous evaluation of these activities for remission of disease and the education of the patient and his/her caregivers.

Treatment consensus for management of polymyositis and dermatomyositis among rheumatologists, neurologists and dermatologists.

Although rheumatologists, neurologists and dermatologists see patients with polymyositis (PM) and dermatomyositis (DM), their management appears to vary depending on the physician's specialty. The aim of the present study was to establish the treatment consensus among specialists of the three fields to standardize the patient care. We formed a research team supported by a grant from the Ministry of Health, Labor and Welfare, Japan. Clinical questions (CQ) on the management of PM and DM were raised. A published work search on CQ was performed primarily using PubMed. Using the nominal group technique, qualified studies and results in the published work were evaluated and discussed to reach consensus recommendations. They were sent out to the Japan College of Rheumatology, Japanese Society of Neurology and Japanese Dermatological Association for their approval. We reached a consensus in 23 CQ and made recommendations and a decision tree for management was proposed. They were officially approved by the three scientific societies. In conclusion, a multidisciplinary treatment consensus for the management of PM and DM was established for the first time.

Treatment consensus for management of polymyositis and dermatomyositis among rheumatologists, neurologists and dermatologists.

Although rheumatologists, neurologists and dermatologists see patients with polymyositis (PM) and dermatomyositis (DM), their management appears to vary depending on the physician's specialty. The aim of the present study was to establish the treatment consensus among specialists of the three fields to standardize the patient care. We formed a research team supported by a grant from the Ministry of Health, Labor and Welfare, Japan. Clinical questions (CQ) on the management of PM and DM were raised. A published work search on CQ was performed primarily using PubMed. Using the nominal group technique, qualified studies and results in the published work were evaluated and discussed to reach consensus recommendations. They were sent out to the Japan College of Rheumatology, Japanese Society of Neurology and Japanese Dermatological Association for their approval. We reached a consensus in 23 CQ and made recommendations and a decision tree for management was proposed. They were officially approved by the three scientific societies. In conclusion, a multidisciplinary treatment consensus for the management of PM and DM was established for the first time.

Guidelines of the Brazilian Society of Rheumatology for the treatment of systemic autoimmune myopathies

Abstract Background: Recommendations of the Myopathy Committee of the Brazilian Society of Rheumatology for the management and therapy of systemic autoimmune myopathies (SAM). Main body: The review of the literature was done in the search for the Medline (PubMed), Embase and Cochrane databases including studies published until June 2018. The Prisma was used for the systematic review and the articles were evaluated according to the levels of Oxford evidence. Ten recommendations were developed addressing the management and therapy of systemic autoimmune myopathies. Conclusions: Robust data to guide the therapeutic process are scarce. Although not proven effective in controlled clinical trials, glucocorticoid represents first-line drugs in the treatment of SAM. Intravenous immunoglobulin is considered in induction for refractory cases of SAM or when immunosuppressive drugs are contra-indicated. Consideration should be given to the early introduction of immunosuppressive drugs. There is no specific period determined for the suspension of glucocorticoid and immunosuppressive drugs when individually evaluating patients with SAM. A key component for treatment in an early rehabilitation program is the inclusion of strengthbuilding and aerobic exercises, in addition to a rigorous evaluation of these activities for remission of disease and the education of the patient and his/her caregivers.

Long-term follow-up of 76 Iranian patients with idiopathic inflammatory myopathies.

AIM: This study aimed to follow up patients with polymyositis (PM) and/or dermatomyositis (DM) to determine survival rate, pattern of disease, response to treatment, malignancy incidence and poor prognostic factors (PPFs). METHOD: A total of 76 patients with PM (n = 47) and/or DM (n = 29) based on Bohan and Peter diagnostic criteria referred to the Imam-Reza Hospital were followed up from 2004 to 2016. The follow-up period was considered from diagnosis to patient's death or last visit. All patients underwent physical examinations and data including age, sex, disease duration, disease subtype, pattern of disease, PPFs and malignancy incidence were collected. RESULTS: Mean age at diagnosis was 45.49 ± 10.88 years and women were predominant (84.2%). Course of disease in the majority of patients (52.6%) was polyphasic, followed by monophasic (31.6%) and chronic-progressive (5.3%). The 1-, 5- and 10-year survival rates were 96%, 93% and 92%, respectively. Delay in treatment and dysphagia were common PPFs in the present study. The majority of patients responded to treatment (88.2%) and there were significant differences in cancer and dysphagia between responders and non-responders to treatment (P < 0.05). The most common cause of death was cancer in four of eight deaths. There was significant difference in survival rates between patients with and without pulmonary involvement (P = 0.001). Moreover, the survival rates were significantly lower in patients with malignancy (P = 0.001). CONCLUSION: Presence of dysphagia and cancer were associated with poor response to treatment. Pulmonary involvement and cancer incidence significantly affect survival rate. Furthermore, since cancer is the most common cause of death, so this study emphasizes the importance of careful cancer screening in these patients.

Treatment of inflammatory myopathies.

INTRODUCTION: The idiopathic inflammatory myopathies (IIM) dermatomyositis (DM) and polymyositis (PM) are chronic diseases affecting the striated muscles with variable involvement of other organs. Glucocorticoids are considered the cornerstone of treatment, but some patients require adjunctive immunosuppressive agents because of insufficient response to glucocorticoids, flares upon glucocorticoid tapering, or glucocorticoid-related adverse events. Areas covered: The aim of this article was to review (PubMed search until February 2018) the evidence on established and new therapies derived from randomized controlled trials (RCTs) on adult DM and PM. In addition, key data from open-label trials, case reports, and abstracts were included where data from RCT were lacking. Expert commentary: Numerous synthetic and biological immunosuppressive agents are currently available to treat the IIM, sometimes in combination. The choice of the specific medication in the individual patient depends upon the disease phenotype and patient's characteristics. Exercise improves muscle performance without causing disease flares and should be an integral part of the treatment of the IIM. Prompt diagnosis and treatment can lead to better outcome.

Current Classification and Management of Inflammatory Myopathies.

Inflammatory disorders of the skeletal muscle include polymyositis (PM), dermatomyositis (DM), (immune mediated) necrotizing myopathy (NM), overlap syndrome with myositis (overlap myositis, OM) including anti-synthetase syndrome (ASS), and inclusion body myositis (IBM). Whereas DM occurs in children and adults, all other forms of myositis mostly develop in middle aged individuals. Apart from a slowly progressive, chronic disease course in IBM, patients with myositis typically present with a subacute onset of weakness of arms and legs, often associated with pain and clearly elevated creatine kinase in the serum. PM, DM and most patients with NM and OM usually respond to immunosuppressive therapy, whereas IBM is largely refractory to treatment. The diagnosis of myositis requires careful and combinatorial assessment of (1) clinical symptoms including pattern of weakness and paraclinical tests such as MRI of the muscle and electromyography (EMG), (2) broad analysis of auto-antibodies associated with myositis, and (3) detailed histopathological work-up of a skeletal muscle biopsy. This review provides a comprehensive overview of the current classification, diagnostic pathway, treatment regimen and pathomechanistic understanding of myositis.

Hospitalization mortality and associated risk factors in patients with polymyositis and dermatomyositis: A retrospective case-control study.

BACKGROUND: Polymyositis and dermatomyositis (PM/DM) are systemic autoimmune diseases with multiple organ involvements that manifest as muscular and cutaneous disorders, interstitial lung disease (ILD) and malignancies. However, information concerning the outcomes and associated factors for PM/DM patients who are hospitalized is limited. METHODS: We retrospectively reviewed the medical charts of PM/DM patients admitted to a Chinese tertiary referral hospital (Peking Union Medical College Hospital, PUMCH) from 2008 to 2014. The deceased group included 63 patients who had "deceased discharge" status or were confirmed to have died within two weeks of hospital discharge. The demographic data, clinical manifestations, and direct causes of death were analyzed retrospectively. Medical records for 126 age- and sex-matched PM/DM patients were selected as controls from 982 inpatients successively admitted to the same center during the same period. In addition to the comparison of clinical manifestations between the two groups, binary logistic regression was conducted to explore the risk factors related to PM/DM mortality. RESULTS: Over the past 6 years at PUMCH, the in-hospital mortality rate of PM/DM patients was 4.58%. The male gender and the elder patients had a high risk of death (P = 0.031 and P = 0.001 respectively). The three most frequent causes of death for PM/DM patients were pulmonary infection (35%), ILD exacerbation (21%) or both conditions (25%). Pulmonary infection (P<0.001, OR = 5.63, 95% CI, 2.37-13.36), pneumomediastinum (P = 0.041, OR = 11.02, 95%CI, 1.10-110.54), Gottron's papules (P = 0.010, OR = 3.24, 95%CI, 1.32-7.97), and elevated erythrocyte sedimentation rate (ESR) (P = 0.005, OR = 9.9, 95%CI 2.0-49.0) were independent risk factors for in-hospital mortality of PM/DM patients. CONCLUSION: PM/DM patients continue to display high in-hospital mortality. Pulmonary infection is the strongest predictor of poor prognosis in PM/DM patients, followed by pneumomediastinum, Gottron's papules, and elevated ESR.