Polymyositis is a rare and favourable outcome subtype of idiopathic inflammatory myopathy in Chinese patients.

OBJECTIVES: To investigate the prevalence and characteristics of typical polymyositis (PM) in Chinese patients with idiopathic inflammatory myopathy (IIM). METHODS: Patients diagnosed with IIM according to the 2017 EULAR/ACR criteria were included. Serological aspects including myositis-specific antibodies (MSA) and pathological data were re-evaluated. The diagnosis of typical PM was strictly done using the pathological criteria, while excluding other IIM subtypes such as dermatomyositis (DM), immune-mediated necrotising myopathies (IMNM), anti-synthetase syndrome (ASS), and sporadic inclusion body myositis (sIBM), based on their respective diagnostic criteria. RESULTS: A total of 544 IIM patients with muscle biopsy were involved, and 129 of them were diagnosed with initial PM according to the 2017 EULAR/ACR criteria. Only 6 (1.1%, 6/544) patients met the strict definition of typical PM after re-evaluation. Patients with typical PM were MSA-negative (100% vs. 35.7%, p=0.003) and had CD8+ T cells surrounding or invading non-necrotic muscle fibres in muscle biopsies (100% vs. 7.8%, p<0.001) compared to the initially diagnosed PM patients. All typical PM patients achieved clinical remission at the second-year follow-up. Typical PM patients had a favourable prognosis compared to MSA-negative IMNM and unspecific myositis patients. CONCLUSIONS: Strictly defined typical PM is a rare clinical subtype in Chinese IIM patients. Typical PM patients with classical pathology were MSA-negative and responded well to treatment and had a favourable prognosis. It is crucial for clinicians to combine clinical, serological, and pathological features to properly distinguish PM from other IIM subtypes.

Prevalence of hearing loss, tinnitus, vertigo and sudden deafness among patients with polymyositis and dermatomyositis.

Little is known about a possible association of autoimmune inner ear disease among patients diagnosed with polymyositis (PM)/dermatomyositis (DM). This study aimed to explore differences in the prevalence of inner ear symptoms among patients with and without PM/DM using a nationwide population-based dataset. Data for this study were retrieved from the Taiwan National Health Insurance Research Database. The study sample included 1622 patients diagnosed with PM/DM and 8109 propensity-score matched comparison patients without PM/DM. We performed multivariate logistic regressions to calculate odds ratios (ORs) and 95% confidence interval (CI) for tinnitus, hearing loss, sudden deafness, and vertigo among patients with PM/DM versus comparison patients. Chi-square tests showed statistically significant differences between patients with PM/DM and comparison patients in the prevalence of tinnitus (16.1% vs. 12.7%, p < 0.001), non-conductive hearing loss (9.2% vs. 6.8%, p < 0.001), and vertigo (14.4% vs. 11.1%, p < 0.001). The adjusted ORs for tinnitus, non-conductive hearing loss, and vertigo, respectively, were 1.332 (95% CI = 1.147-1.547), 1.399 (95% CI = 1.154-1.696), and 1.374 (95% CI = 1.173-1.611) for patients with PM/DM when compared to comparison patients. Our study finds that patients with PM/DM have higher prevalence rates of tinnitus, non-conductive hearing loss, and vertigo than comparison patients.

Cancer Risk and Mortality in Hospitalized Patients With Idiopathic Inflammatory Myopathies in Western Australia.

OBJECTIVE: To compare cancer incidence, type, and survival between patients with idiopathic inflammatory myopathies (IIMs) in Western Australia (WA) and the general population. METHODS: Administrative health data for hospitalized patients with incident IIM (n = 803, 56.5% female, median age 62.0 yrs), classified by a validated algorithm as polymyositis (PM; 36.2%), dermatomyositis (DM; 27.4%), inclusion body myositis (IBM; 17.1%), overlap myositis (OM; 10.7%), and other IIM (8.6%), were linked to WA cancer and death registries for the period of 1980 to 2014. Cancer incidence rates (CIRs) before and after IIM diagnosis as well as cancer mortality were compared with age-, sex-, and calendar year-matched controls (n = 3225, 54.9% female, median age 64 yrs) by rate ratios (RRs) and Kaplan-Meier survival estimates. RESULTS: The prediagnosis CIR was similar for patients with IIM and controls (6.57 vs 5.95; RR 1.11, 95% CI 0.88-1.39) and for patients evolving to DM (n = 220) or other IIM subtypes (6.59 vs 6.56; RR 1.01, 95% CI 0.38-3.69). During follow-up, CIR was higher for all DM (4.05, 95% CI 3.04-5.29), with increased CIR for lung cancer vs controls (1.05 vs 0.33; RR 3.18, 95% CI 1.71-5.47). Cancer post diagnosis shortened life span by 59 months for patients with IIM (103 vs 162 months, P < 0.01), but reduced survival rates were observed only in patients with DM and IBM. CONCLUSION: Cancer risk was not increased prior to IIM, but CIR for lung cancer was increased following DM diagnosis. As cancer reduced survival only in patients with DM and IBM, these data support a strategy of limited cancer screening in IIM.

The spectrum of idiopathic inflammatory myopathies in Western Australia: epidemiological characteristics and mortality over time.

To determine long term overall and subgroup specific incidence rates and associated mortality for idiopathic inflammatory myopathies (IIM) in a population wide study. We included patients hospitalised between 1980 and 2015 with incident IIM as defined by relevant diagnostic codes for dermatomyositis (DM) polymyositis (PM), inclusion body myositis (IBM), other IIM and overlap myositis (OM) in the Western Australia Health Hospital Morbidity Data Collection (n = 846). Trends over time for annual incidence rate per million population (AIR) were analysed by least square regression and Kaplan-Meier survival and mortality rates (MR)/100 person years compared with a matched control group (n = 3681). The averaged AIR for all IIM was 19 (CI 10.4-27.5) and stable over time with point prevalence reaching 205.3 (CI 185.6-226.6) per million in 2015. Over time, the AIR for DM 5.0 (CI 0.6-9.4) and IBM 3.3 (CI 0.7-9.6) was stable, while AIR decreased for PM (p < 0.01) and increased for other IIM (p < 0.01) and OM (p < 0.01). IBM patients were eldest at diagnosis (68 years, CI 59-77) with male preponderance in IBM (53.4%) and other IIM (55.8%) groups. Crude mortality (54.5 vs 41.3%), MR ratio (6.65 vs 5.91) and 5 (65.8% vs 71.6%) and 10-year (52.5% vs 58.7%) survival were all worse for IIM patients (all p < 0.05). IBM patients had highest MR (10.1; CI 8.38-12.14) and lowest 10-year survival (39.2%). While cardiovascular disease and cancer were predominant causes of death, they were proportionally lower in IIM patients, where respiratory and rheumatic disease were more frequent causes of death. While the overall incidence of IIM in WA was stable over 35 years, the spectrum of IIM has changed significantly with increases especially in other IIM and OM. The overall prognosis with IIM remains guarded with 10-year survival just over 50%.

Serum uric acid is independently associated with hypertension in patients with polymyositis and dermatomyositis.

Serum uric acid (UA), as an antioxidant, has been associated with hypertension in the general population. Hypertension is highly prevalent in patients with polymyositis and dermatomyositis (PM/DM). Owning elevated levels of reactive oxygen species, patients with PM/DM have lower concentrations of UA in comparison with healthy people. We explored a potential association between UA levels and hypertension in PM/DM and evaluated whether this association is independent of hypertension risk factors, PM/DM characteristics and relevant drugs. A total of 472 PM/DM patients were assessed. UA and related laboratory data were measured. Demographic, hypertension-related factors, PM/DM characteristics and drug use were assessed as potential covariates. Results were analyzed using logistic models to test the independence of the association between UA and hypertension. UA levels were higher in hypertension subjects compared to non-hypertensive PM/DM patients [284.70 (239.93-357.38) vs 264.00(222.50-322.75), p = .017]. When adjusted for hypertension risk factors, PM/DM characteristics and drugs, the odds of being a hypertensive PM/DM patient per 1 µmol/L UA increase were significantly increased: odds ratio = 1.473 (95% confidence interval:1.063-2.042, p = .020). This cross-sectional study suggests that UA levels are independently associated with hypertension in PM/DM patients.

Characteristics and risk of interstitial lung disease in dermatomyositis and polymyositis: a retrospective cohort study in Japan.

Dermatomyositis and polymyositis are rare, idiopathic inflammatory myopathies. Interstitial lung disease is one of the most common and potentially severe extra-muscular manifestations of dermatomyositis and polymyositis and is strongly linked to poor prognosis and early mortality. We aimed to characterise the demographic and clinical characteristics, incidence, and treatment of interstitial lung disease in patients with dermatomyositis or polymyositis. We conducted a retrospective cohort study using the Japan Medical Data Center healthcare claims database. Patients in the database with dermatomyositis (International Classification of Disease version 10 M33.0, M33.1, M33.9) or polymyositis (M33.2) from 01-Jan-2011 until 31-Dec-2019 were identified and followed-up for interstitial lung disease (J84.x) until death, dis-enrolment, or study end (31 December 2020). Cumulative risk curves compared interstitial lung disease risk in dermatomyositis versus polymyositis. Risk factors were evaluated by Cox proportional hazard models. There were 886 patients with dermatomyositis and 745 patients with polymyositis included in the cohort analysis. Mean (standard deviation) age at dermatomyositis/polymyositis diagnosis was 46.0 (16.0)/49.7 (13.3) years and 300 (34%)/104 (14%) developed interstitial lung disease during follow-up. The incidence rate of interstitial lung disease per 100 person-years was 18.42 (95% CI 16.42-20.59) for dermatomyositis and 5.39 (95% CI 4.43-6.50) for polymyositis. In the analysis adjusted for sex, age, and comorbidity score, the risk of interstitial lung disease was significantly higher in patients with dermatomyositis than with polymyositis (hazard ratio 2.72, 95% CI 2.18-3.41). The rate diverged markedly between the groups in the first year after diagnosis. Risk factors for interstitial lung disease were older age in dermatomyositis, female sex and rheumatoid arthritis in polymyositis. Glucocorticoids with/without tacrolimus were the most common newly prescribed drugs after the interstitial lung disease diagnosis. In conclusion, the risk of developing interstitial lung disease was significantly higher in patients with dermatomyositis than with polymyositis, and risk factors were different in the 2 patient groups.

The Prevalence of Dementia among Dermatomyositis and Polymyositis Patients: A Retrospective Cohort Study.

BACKGROUND: Polymyositis (PM) and dermatomyositis (DM) are inflammatory mediated myopathies characterized by progressive symmetric proximal muscle weakness and associated with extra-muscular involvement. Central nervous system complications are rarely reported with these diseases. OBJECTIVES: To investigate the association between dementia and PM/DM. METHODS: A retrospective cohort study was conducted using a database from Clalit Health Care, the largest health maintenance organization in Israel. Patients with a first recorded diagnosis of PM/DM were included and were compared with age- and sex-matched controls by a ratio of 1:5. The prevalence of dementia among PM/DM patients compared to controls was assessed using a univariate and a multivariable model. Binary logistic regression analysis was conducted to assess the association of different factors with dementia within the PM/DM cohort. RESULTS: The study included 2085 PM/DM cases (17.0%) and 10,193 age- and sex-matched controls (83.0%). During the follow-up time, 36 PM/DM patients were diagnosed with dementia compared to 160 controls, with a univariate hazard ratio (HR) of 1.10 (95% confidence interval [95%CI] 0.77-1.58). Within the PM/DM cohort, significant predictors for the development of dementia included increased age at diagnosis (5 years increment; OR 1.86, 95%CI 1.57-2.21, P < 0.001) and treatment with glucocorticoids (OR 5.40, 95%CI 1.67-17.67, P = 0.005). CONCLUSIONS: In our cohort, inflammatory myopathies were not associated with dementia. Age and treatment with glucocorticoids were associated with dementia. If dementia is diagnosed in patients with inflammatory myopathies, other systemic causes should be investigated.

Polymyositis/dermatomyositis readmissions: analysis of the nationwide readmission database.

BACKGROUND: There is a scarcity of national population-based studies on polymyositis (PM)/dermatomyositis (DM) readmissions in the USA. In this study, we aim to describe the rates, reasons for readmissions, and characteristics of readmissions for adults hospitalized for PM/DM in the USA. METHODS: We analyzed the 2018 Nationwide Readmissions Database (NRD). We included index hospitalizations for all adult DM/PM patients with a principal diagnosis of PM/DM using ICD-10 codes. We excluded elective and traumatic readmissions. Using a "rank" command in STATA, the most common specific principal diagnosis of readmissions was outlined. Chi-square tests were used to compare baseline characteristics between readmissions and index hospitalizations. STATA 16 was used for analysis. RESULTS: A total of 1610, 1286, and 842 index hospitalizations with a principal diagnosis of PM/DM, that were discharged alive, were included in the 30-, 90-, and 180-day readmission analysis, respectively. Among these, 193 (12%), 276 (21.5%), and 240 (28.5%) were readmitted within 30, 90, and 180 days, respectively. PM and sepsis were the most common reasons for reasons across the 3 timeframes. 30-day readmissions were responsible for an aggregate of 4.1 million US dollars in total hospital cost and 1518 hospital days in 2018. Compared to index hospitalizations, 30-day readmissions have higher Charlson Comorbidity Index scores, severe-extreme loss of function, obesity, and deep venous thrombosis. CONCLUSION: About a third of PM/DM hospitalized patients are readmitted within 180 days. Readmissions constitute a significant economic burden to the health care system. PM and sepsis are the main reasons for readmissions. Key points • About a third of polymyositis (PM)/dermatomyositis (DM) hospitalized patients are readmitted within 180 days • PM and sepsis are the main reasons for readmissions. • Readmissions of PM/DM Patients constitute a significant economic burden to the health care system. • Compared to index hospitalizations, 30-day readmissions have higher Charlson comorbidity index scores, severe-extreme loss of function, obesity, and deep venous thrombosis.

Clinical Characteristics and Risk Factors of Polymyositis and Dermatomyositis Combined with Interstitial Lung Disease in Patients Residing in the Northeast Sichuan Province of China.

BACKGROUND: Polymyositis (PM) and dermatomyositis (DM) are non-suppurative and autoimmune inflammatory diseases of striated muscle. Interstitial lung disease (ILD) is a group of heterogeneous diseases that mainly involve the pulmonary interstitium, alveoli, and/or bronchioles, also known as diffuse parenchymal lung disease (DPLD). A significant cause of death in persons with polymyositis (PM) and dermatomyositis (DM) is concurrent interstitial lung disease (ILD). However, research on the clinical characteristics and associated influencing factors of PM/DM combined with ILD (PM/DM-ILD) is currently scarce in China. OBJECTIVE: The study aimed to probe the clinical features and risk factors of PM/DM-ILD. METHODS: The data of 130 patients with PM/DM were gathered. General medical status, clinical symptoms, laboratory parameters, high-resolution CT, therapeutic outcomes, and prognoses were retrospectively reviewed in patients with PM/DM with (ILD group) and without (NILD) ILD. RESULTS: The age of the ILD group (n=65) was more than the NILD group (n=65), and the difference was statistically significant; there were no significant between-group variations in the PM/DM ratio, sex, or duration of the disease. The initial symptoms were arthritis and respiratory symptoms in the ILD group, and myasthenia symptoms in the NILD group. Incidences of Raynaud's phenomenon, dry cough, expectoration, dyspnea on exertion, arthritis, fever, total globulin (GLOB), erythrocyte sedimentation rate (ESR), and anti-Jo-1 antibody rate were higher for ILD; however, albumin (ALB), creatine kinase aspartate aminotransferase activity ratio (CK/AST) and CK levels were significantly lower in the ILD group. Bivariate logistic regression analysis showed age, dry cough, arthritis, dyspnea on exertion, anti-Jo-1 antibody, and elevated GLOB to be independent risk factors for ILD among patients with PM/DM. CONCLUSION: Advanced age, dry cough, arthritis, dyspnea on exertion, anti-Jo-1 antibody positivity, and elevated GLOB level are risk factors for PM/DM-ILD. This information could be utilized to carefully monitor changing lung function in these patients.

Inflammatory Bowel Diseases Are Associated with Polymyositis and Dermatomyositis-A Retrospective Cohort Analysis.

Background and Objectives: Polymyositis and dermatomyositis (PM/DM) are classified as polygenic autoimmune diseases, whereas inflammatory bowel disease (IBD) is considered a polygenic autoinflammatory disease. In the literature, several cases exist reporting the co-occurrence of both conditions. At the molecular level, PM/DM and IBD share common genetic determinants including interferon regulatory factor and vitamin D receptor susceptibility loci. Accumulating evidence underline several indicators that confer poor prognosis in IBD, including antinuclear antibody positivity and the presence of other autoimmune diseases, therefore the aim of this study is to assess the association between these entities. Materials and Methods: This is a population-based retrospective study using data retrieved from a large electronic medical record in Israel, the Clalit health registry. The sample included PM/DM patients and age- and sex-frequency matched controls. The prevalence of IBD in PM/DM was compared between the two groups and logistic regression was applied to control for confounding variables. Predictors of IBD in patients with PM/DM were also explored. Results: Our study included 12,278 subjects with 2085 PM/DM patients and 10,193 age- and sex- frequency-matched controls. The incidence of IBD in patients with PM/DM was significantly higher even after controlling for various confounding variables (OR of 1.73, 95% CI 1.05-2.86, p-value = 0.033). Anti-nuclear antibodies (ANA) positivity was found to be an independent predictor for IBD diagnosis in patients with PM/DM (OR 3.67, 95% CI 1.01-13.36, p = 0.048). Conclusion: Our analysis reports an association between IBD and PM/DM. Such association could point towards a common pathophysiological background. Further research is needed to further describe the clinical courses and whether a unique therapeutic approach is warranted.

Tacrolimus in Patients With Interstitial Pneumonia Associated With Polymyositis or Dermatomyositis: Interim Report of Postmarketing Surveillance in Japan.

OBJECTIVE: The calcineurin inhibitor tacrolimus has been approved in Japan for the treatment of interstitial pneumonia (IP) in patients with polymyositis (PM) and dermatomyositis (DM). Postmarketing surveillance was initiated to examine long-term outcomes of immunosuppressive regimens containing tacrolimus in real-world settings. METHODS: Observational, prospective, postmarketing surveillance is ongoing in 179 patients with PM/DM-associated IP initiating treatment with tacrolimus. We report interim findings after 2 years of follow-up. Cumulative overall survival was assessed using Kaplan-Meier analysis. Potential prognostic factors for mortality were assessed by univariate Cox proportional hazards analysis. RESULTS: A total of 170 patients were included in this analysis. At the time of starting treatment with tacrolimus, almost all patients were receiving corticosteroids (98.8%), and cyclophosphamide was additionally used in 42 patients (24.7%). Forty-nine patients (28.8%) discontinued tacrolimus during follow-up, mainly due to loss to follow-up, patient death, and adverse events. Mean (SD) oral corticosteroid dose decreased from 32.4 (21.6) mg/day at baseline to 7.6 (4.2) mg/day at 2 years. Overall survival at 2 years was 90.3%; corresponding progression-free survival was 62.5%. Factors found to be associated with all-cause mortality included diagnosis of clinically amyopathic DM (hazard ratio [HR] 9.04, 95% CI 1.18-69.51 vs PM), ferritin level 500 to < 1500 ng/mL (HR 8.61, 95% CI 2.51-29.45 vs < 500 ng/mL), and presence of antimelanoma differentiation-associated gene 5 antibodies (HR 8.16, 95% CI 1.03-64.47 vs absence). CONCLUSION: Immunosuppressive regimens containing tacrolimus appear useful for the management of IP in patients with PM/DM. [ClinicalTrials.gov: NCT02159651].

Anti-mitochondrial antibodies in Indian patients with idiopathic inflammatory myopathies.

AIMS: Anti-mitochondrial antibodies (AMAs) are associated with distinct clinical phenotypes including cardiac and hepatic manifestations in idiopathic inflammatory myopathies (IIMs). This article studies the prevalence, clinical characteristics and outcomes of AMA in Indian patients with IIM. METHODS: Patients (97: 81 adult, 16 juvenile) clinically diagnosed with polymyositis or antibody-negative IIM were retrieved from the MyoCite bio-archive. They were tested for myositis-specific autoantibodies / myositis autoantibodies (MSAs/MAAs) using line immunoassay and antinuclear antibodies and AMAs using immunofluorescence assay (IFA). Patients were also screened for cardiac biomarkers (cardiac troponin I [c-TnI] and N terminal-pro brain natriuretic peptide [NT-pro-BNP] using immunometric immunoassay technique and enhanced chemiluminescence assay testing respectively) and hepatic manifestations using AMA testing. Results were formulated after carrying out analytical tests. RESULTS: Of the cohort, 5 adults (6.2%) (M:F 0:1) with a median age and disease duration of 37 years and 2 months respectively, tested AMA+ while the children tested negative. Dermatomyositis was the commonest phenotype, with amyopathic forms being common, often with MSA positivity. Cancer-associated myositis and polymyositis were also seen. AMA positivity is associated with Gottron's sign and calcinosis. Comparable levels of C-TnI and NT-pro-BNP and AMA testing in patients help to rule out subclinical cardiac and hepatic involvement respectively. CONCLUSION: Anti-mitochondrial antibodies are rare (6.2%) in different subtypes of IIM in the Indian population, and often coexist with MSAs. Their negative association with cardiac and hepatic involvement and probable association with Gottron's sign and calcinosis merit further investigation and long-term follow-up to understand the entire spectrum of the disease.

Cardiovascular events in adult polymyositis and dermatomyositis: a meta-analysis of observational studies.

OBJECTIVES: We aimed to review whether PM and DM patients have an increased cardiovascular (CV) risk, including ischaemic heart disease (IHD), cerebrovascular accidents (CVA) and venous thromboembolism. METHODS: We searched PubMed, Embase and the Cochrane database for relevant studies from inception to February 2021. RESULTS: Twenty-two studies comprising 25 433 patients were included. With PM/DM vs general populations, the risk was significantly increased for CV events [relative risk (RR) = 2.37, 95% CI: 1.86, 3.02]. The RR of CV events for males with PM/DM was higher than for females (RR = 1.43; 95% CI: 1.17, 1.74). PM/DM patients followed for one to five years had a significantly higher CV risk than those followed for five to ten years (RR = 3.51, 95% CI: 1.95, 6.32). The risk was increased for North Americans (RR = 4.28, 95% CI: 2.57, 7.11), Europeans (RR = 2.29, 95% CI: 1.58, 3.31) and Asians (RR = 2.03, 95% CI: 1.41, 2.90). Our meta-analysis found that the elevated CV event risk was related to PM (RR = 2.35, 95% CI: 1.51, 3.66) and DM (RR = 2.55, 95% CI: 1.66, 3.93). Subgroup analyses showed that the risk was significantly increased for IHD (RR = 1.76, 95% CI: 1.40, 2.21), CVA morbidity (RR = 1.31, 95% CI: 1.03, 1.67) and ischaemic stroke (IS) (RR = 1.47, 95% CI: 1.26, 1.73), with no statistically significant increased risk of haemorrhagic stroke mortality (RR = 1.43, 95% CI: 0.92, 2.21). The CV event risk was increased for venous thromboembolism (RR = 4.60, 95% CI: 3.17, 6.66), deep venous thrombosis (RR = 5.53, 95% CI: 3.25, 9.39) and pulmonary embolism (RR = 5.26, 95% CI: 2.62, 10.55). CONCLUSION: This meta-analysis found that PM/DM patients had a ∼2.37 times increased CV risk, particularly males diagnosed in the previous five years. PM/DM may be an independent risk factor for developing IHD, IS, deep venous thrombosis and pulmonary embolism.

Infection is not rare in patients with idiopathic inflammatory myopathies.

OBJECTIVES: To assess the prevalence and characteristics of infections in patients with idiopathic inflammatory myopathies (IIM) and analyse risk factors for infection using clinical presentation and biochemical findings of IIM. METHODS: Retrospective review of the medical records of patients with IIM followed up in a single medical centre from January 2008 to January 2018. RESULTS: Of the 779 patients with IIM, 215 (27.6%) suffered from infections. The prevalence of infection in dermatomyositis (DM) (29.8%) was more than polymyositis (PM) (18.5%). The lung was the most common infection site (66.5%). Multivariate analyses demonstrated that methylprednisolone pulse (MP) (OR=3.22; 95% CI=1.60 - 6.48; p=0.001), age of onset >50 years (OR=1.02; 95% CI=1.00 - 1.03; p=0.011), anti-melanoma differentiation-associated gene 5 (MDA5) antibody (OR=1.93; 95% CI=1.20 - 3.11; p=0.007), lymphocyte count <1200/mm3 (OR=2.85; 95% CI=1.89 - 4.30; p<0.001), and interstitial lung diseases (ILD) (OR=2.03; 95% CI=1.30 - 3.71; p=0.002) are independent risk factors for infection. Survival analysis demonstrated that the three-year survival rate in the infection group was lower than the no-infection group (75.3% vs. 94.7%, p < 0.001). CONCLUSIONS: Among hospitalised individuals with IIM, infection is frequent and the leading cause of mortality. The anti-MDA5 antibody, lymphopenia, ILD, old age, and treatment with MP are contributing factors in the development of infections in patients with IIM.

Disease burden and treatment sequence of polymyositis and dermatomyositis patients in Japan: a real-world evidence study.

INTRODUCTION/OBJECTIVES: Since new consensus on polymyositis (PM) and dermatomyositis (DM) were released in Japan, an updated evidence on treatment landscape and PM/DM burden was essential. This study evaluates treatment burden and overall treatment cost of PM/DM-related inpatient and outpatient visits, treatments, and procedures/patient/year. METHOD: This retrospective, observational study analyzed insurance claims from Japan Medical Data Center (JMDC) database. Patients with at least one PM/DM diagnosis/one dispensation of treatment between 1 January 2009 and 31 December 2019 were enrolled. Patient characteristics, treatment patterns and sequence, treatment choices, healthcare resource utilization (HCRU), and related costs were assessed. Chi-square test and linear regression model were used to assess impact of patient characteristics on treatment choice. RESULTS: Patients (836/4,961) receiving a relevant treatment were analyzed. Heart disease (35%), interstitial lung disease (27%), and diabetes mellitus (26%) were frequently identified as comorbidities. Concomitant dispensation of immunosuppressants and systemic steroids was largely found in first and second line of treatment (LoT) while systemic steroids remained as single dominant treatment across all LoTs. HCRU was very low for inpatient visits (0.68 [1.43]) or rehabilitation (4.74 [14.57]). The mean (SD) number of inpatient visits decreased from first (1.23 [2.32]) to third year (0.11 [0.54]). Total mean (SD) healthcare cost per patients per year was ¥ 3,815,912 (7,412,241), with overall drug dispensation compounding to 80% of total cost. CONCLUSIONS: High concomitant immunosuppressant and systemic steroid prescriptions in first LoT recommend early optimal treatment to manage PM/DM. Although inpatient costs are low, outpatient dispensation costs increase overall economic burden.

Anti-Polymyositis/Scl Antibodies in Systemic Sclerosis: Clinical Associations in a Multicentric Spanish Cohort and Review of the Literature.

OBJECTIVES: To assess the clinical profile of patients with anti-polymyositis/Scl (PM/Scl) antibodies in a cohort of Spanish patients with systemic sclerosis. METHODS: From the Spanish Scleroderma Study Group database, we selected patients in whom PM/Scl antibodies had been tested. We compared demographic, clinical, laboratory, and survival data between patients with and without PM/Scl antibodies. RESULTS: Seventy-two of 947 patients (7.6%) tested positive for PM/Scl antibodies. Patients with PM/Scl antibodies presented initially with more puffy fingers and arthralgias but less Raynaud phenomenon. Regarding cumulative manifestations, myositis and arthritis were more prevalent in patients with PM/Scl antibodies, as well as pulmonary fibrosis. On the contrary, patients with PM/Scl antibodies had less pulmonary hypertension. No difference in terms of survival at 5 and 10 years was noticed between the 2 groups. CONCLUSIONS: In systemic sclerosis patients from Spain, PM/Scl antibodies are associated with a distinct clinical profile. However, PM/Scl antibodies did not influence survival.

Reasons for Hospitalization and In-Hospital Mortality in Adults With Dermatomyositis and Polymyositis.

OBJECTIVE: Dermatomyositis (DM) and polymyositis (PM) are systemic autoimmune diseases that have been associated with high in-hospital mortality (IHM). The aim of this study was to use the National Inpatient Sample (NIS), a large US population database, to determine the reasons for hospitalization and IHM in patients with DM and PM. METHODS: We conducted a medical records review of adult DM/PM hospitalizations in 2016 and 2017 in acute care hospitals across the United States using the NIS. The reasons for IHM and reasons for hospitalization were divided into 19 broad categories based on their principal International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10) diagnosis. RESULTS: A total of 27,140 hospitalizations carried either a principal or secondary ICD-10 code for DM or PM. The main reasons for hospitalization were rheumatologic (22%, n = 6085), cardiovascular (15%, n = 3945), infectious (13%, n = 3515), respiratory (12%, n = 3170), and gastrointestinal, (8%, n = 2150). A total of 3.5% of all patients experienced IHM. Infectious (34%, n = 325), respiratory (23%, n = 215), and cardiovascular (15%, n = 140) diagnoses were the most common reasons for IHM. Sepsis ICD-10 A41.9 was the most frequent specific principal diagnosis for both hospitalizations and IHM. CONCLUSIONS: Our analysis demonstrated that in the NIS the most common reasons for hospitalization in patients with DM/PM were rheumatologic diagnoses. However, IHM in these patients was most frequently from infectious diagnoses, highlighting the need for increased attention to infectious complications in these patients.

Características clínicas, inmunológicas y daño de órganos en pacientes con miopatías inflamatorias idiopáticas / Organ damage clinical and immunological characteristics in patients with idiopathic inflammatory myopathies

Introducción: Las miopatías inflamatorias idiopáticas constituyen un grupo de enfermedades musculares caracterizadas por debilidad muscular crónica e inflamación muscular de etiología desconocida. Objetivo: Identificar las características clínicas e inmunológicas y su relación con el daño de órganos en los pacientes con miopatías inflamatorias idiopáticas. Métodos: Se realizó estudio observacional, descriptivo, transversal, en 52 pacientes con diagnóstico de miopatía inflamatoria idiopática, seguidos en la consulta protocolizada de Reumatología del Hospital Clínico Quirúrgico Hermanos Ameijeiras entre enero 2016 y enero 2017. Para las variables cualitativas se calcularon los porcentajes de cada grupo. Se utilizó Chi-cuadrado de Pearson (estadístico exacto de Fisher). Nivel de significación del 95 por ciento (α = 0,05) para relacionar la presencia de anticuerpos y el tipo de miopatía así como la presencia de manifestaciones clínicas de MII. Resultados: El 80,8 por ciento fueron mujeres y 86,5 por ciento de procedencia urbana. La edad media al comienzo fue 42,8 ± 13,2 años, tiempo de demora al diagnóstico de 8,8 ± 7,0 meses, tiempo medio de evolución de la enfermedad de 7,5 ± 7,1 años. El 80,8 por ciento estaba en remisión, 50 por ciento tenía anticuerpos específicos. La hipertensión arterial se encontró en 28,8 por ciento de los pacientes y 23,1 por ciento presentó neumonía intersticial. La artritis estuvo presente en 96,2 por ciento. El 26,9 por ciento presentaron anticuerpos específicos Jo-1 y 21,2 por ciento Ro 52. Conclusiones: Predominaron los pacientes del sexo femenino en la cuarta década de la vida de procedencia urbana, los anticuerpos específicos encontrados más frecuentes fue el anti Jo-1, asociado a la presencia de neumopatía intersticial(AU)

Introduction: Idiopathic inflammatory myopathies constitute a group of muscle diseases characterized by chronic muscle weakness and muscle inflammation of unknown etiology. Objective: To identify the clinical and immunological characteristics and their relationship with organ damage in patients with idiopathic inflammatory myopathies. Methods: An observational, descriptive, cross-sectional study was carried out in 52 patients with diagnosis of idiopathic inflammatory myopathy, followed in the protocolized consultation of Rheumatology at Hermanos Ameijeiras Clinical and Surgical Hospital from January 2016 to January 2017. For the qualitative variables, the percentages of each group were calculated. Pearson's Chi-square (Fisher's exact statistic) was used. 95percent significance level (α = 0.05) was used to relate the presence of antibodies and the type of myopathy as well as the presence of clinical manifestations of MII. Results: 80.8percent were women and 86.5percent of urban origin. The mean age at the beginning was 42.8 ± 13.2 years, time delay to diagnosis was 8.8 ± 7.0 months, mean time of evolution of the disease of 7.5 ± 7.1 years. 80.8percent were in remission, 50percent had specific antibodies. Hypertension was found in 28.8percent of the patients and 23.1percent had interstitial pneumonia. Arthritis was present in 96.2percent. 26.9percent had specific Jo1 antibodies and 21.2percent had Ro 52. Conclusions: Urban female patients in the fourth decade of life predominated, the most frequent specific antibodies found was anti-Jo-1, associated with the presence of interstitial lung disease(AU)

Association between clinical phenotypes of dermatomyositis and polymyositis with myositis-specific antibodies and overlap systemic autoimmune diseases.

ABSTRACT: The aim of this study was to evaluate the association between clinical phenotypes of dermatomyositis (DM) and polymyositis (PM) with myositis-specific antibodies (MSAs), and overlap diagnosis of systemic autoimmune diseases.This cross-sectional study was conducted on 67 patients with DM and 27 patients with PM recruited from a regional hospital in southern Taiwan. Clinical phenotypes of DM and PM were assessed and MSAs were measured using a commercial line blot assay. The association of clinical phenotypes of DM and PM with MSAs and overlap diagnosis of systemic autoimmune diseases was performed using univariate and multiple logistic regression analyses.Clinically, patients with DM and PM and overlap diagnosis of systemic sclerosis were associated with a higher risk of interstitial lung diseases (ILDs) (odds ratio [OR] = 6.73; P = .048), Raynaud phenomenon (OR = 7.30; P = .034), and malignancy (OR = 350.77; P = .013). The risk of malignancy was also associated with older age (OR 1.31; P = .012), and male patients were associated with a higher risk of fever. For MSAs, anti-aminoacyl-tRNA synthetase antibodies were associated with ILD, antinuclear antibody were associated with a lower risk of arthritis, anti-transcription intermediary factor 1-gamma antibodies were associated with milder symptoms of muscle weakness, anti-Ku antibodies were associated with overlap diagnosis of systemic lupus erythematosus, and anti-Ro52 antibodies were associated with the development of Raynaud phenomenon and Sjögren syndrome.MSAs and overlap diagnosis of systemic sclerosis were significantly associated with clinical phenotypes of DM and PM. Physicians should be vigilant for malignancy in older DM and PM patients with overlap diagnosis of systeic sclerosis. The possibility of developing ILD in patients with overlap diagnosis of systemic sclerosis or serum positivity of anti-aminoacyl-tRNA synthetase antibodies should be considered.