Patient-reported quality of life and working status outcomes in ambulatory patients with idiopathic inflammatory myopathy.

OBJECTIVE: To investigate the health-related quality of life (HR-QoL), work productivity and activity impairment and associated factors among patients with idiopathic inflammatory myopathy (IIM). METHODS: This was an observational, cross-sectional study. The 189 ambulatory patients with IIM were recruited from May 2019 to May 2022. HR-QoL was measured by the European Quality of Life 5-Dimension (EQ-5D) questionnaire. The Work Productivity and Activity Impairment (WPAI) questionnaire was used to evaluate work productivity and activity impairment. The IIM-related parameters were assessed by the 8-item Manual Muscle Test (MMT-8), Myositis Disease Activity Assessment visual analogue scale (MYOACT), Myositis Damage Index (MDI), Disease Activity Score (DAS) and Physician/Patient Global Assessment (PhGA/PtGA). Quantile regression and ordinal logistic regression were performed to identify the factors, considering EQ-5D or WPAI scores as dependent variables, respectively. RESULTS: Of the 189 IIM patients enrolled, 60% had DM, 13% had PM and 27% had clinical amyopathic DM. The median EQ-5D score was 1.00 (95% CI 0.73, 1.00), 28% were employed and 45% of overall work was impaired due to health problems. EQ-5D values were positively associated with MMT-8 and negatively with MYOACT, DAS, MDI-global and PhGA/PtGA. For the WPAI, activity impairment was associated with a lower MMT-8 score, older onset age and higher PhGA only in 25th-75th percentile. Increased PtGA was associated with increased activity and overall working productivity impairment in most quantiles (P<0.05). CONCLUSION: Multiple disease characteristics were associated with reduced HR-QoL or working productivity impairment in patients with IIM, especially for PtGA.

The additional role of anti-nucleosome antibodies in the prediction of renal damage in systemic lupus erythematosus based on CSTAR (XXV).

OBJECTIVES: The predominant determinant of an unfavorable prognosis among Systemic Lupus Erythematosus (SLE) patients resides in the irreversible organ damage. This prospective cohort study aimed to identify the additional value of anti-nucleosome antibodies on organ damage accumulation in SLE patients. METHODS: Based on the Chinese SLE Treatment and Research group (CSTAR) registry, demographic characteristics, autoantibodies profiles, and clinical manifestations were collected at baseline. Follow-up data were collected by reviewing clinical records. RESULTS: Of 2481 SLE patients with full follow-up data, 663 (26.7%) were anti-nucleosome antibodies positive and 1668 (68.0%) were anti-dsDNA antibodies positive. 764 (30.8%) patients developed new organ damage during a mean follow-up of 4.31 ± 2.60 years. At baseline, patients with positive anti-nucleosome antibodies have a higher rate of lupus nephritis (50.7% vs 36.2%, p < .001). According to the multivariable Cox regression analysis, both anti-nucleosome (HR = 1.30, 95% CI, 1.09-1.54, p < .001) and anti-dsDNA antibodies (HR=1.68, 95% CI, 1.38-2.05, p < .001) were associated with organ damage accumulation. Anti-nucleosome (HR = 2.51, 95% CI, 1.81-3.46, p < .001) and anti-dsDNA antibodies (HR = 1.69, 95% CI, 1.39-2.06, p < .001) were independent predictors for renal damage. Furthermore, the combination of the two antibodies can provide more accurate information about renal damage in overall SLE patients (HR = 3.19, 95% CI, 2.49-4.10, p < .001) and patients with lupus nephritis at baseline (HR = 2.86, 95% CI, 2.29-3.57, p < .001). CONCLUSION: Besides anti-dsDNA antibodies, anti-nucleosome antibodies can also provide information about organ damage accrual during follow-up. The ability of co-positivity of anti-nucleosome and anti-dsDNA antibodies in predicting renal damage may lead to additional benefits in the follow-up of these patients.

Early recognition of catastrophic antiphospholipid syndrome in patients with antiphospholipid syndrome based on a Chinese cohort study.

OBJECTIVES: Catastrophic antiphospholipid syndrome (CAPS) is a life-threatening form of antiphospholipid syndrome (APS) with high mortality. We try to develop a predictive model to achieve early recognition of CAPS. METHODS: Data of APS patients referred into Peking Union Medical College Hospital from May 2013 to October 2021 was collected. A binary logistic regression method was used to identify predictors of CAPS, coefficient B was assigned with score value in the development of prediction model, and risk-stratification was based on the calculated scores using the model. RESULTS: Twenty-seven CAPS (11.9%) occurred in 226 APS patients. CAPS was more likely to occur in male secondary APS patients with a history of hypertension, hyperlipidaemia, and arterial thrombosis, presented with haematological, nephrological and immunological abnormalities simultaneously. Hypertension history (OR 5.091, 95% CI 1.119-23.147), anaemia (OR 116.231, 95% CI 10.512-1285.142), elevated LDH (OR 59.743, 95% CI 7.439-479.815) and proteinuria (OR 11.265, 95% CI 2.118-59.930) were independent predictors for CAPS, and the scores were 1, 3, 3 and 2 points, respectively. The risk scores were divided into high-risk (6-9) and low risk (0-5), the risk for CAPS were 54.1% and 0.6%, with sensitivity of 0.963 and specificity of 0.886. The Nagelkerke's R2 (0.739) and the Omnibus test (χ2 =109.231, df=4, p=0.000) indicated the model has a good fit. The AUC of 0.971 indicated good discrimination. The calibration curve in internal validation showed good calibration of this predictive model. CONCLUSIONS: A predictive model of CAPS was developed with hypertension, anaemia, elevated LDH and proteinuria. This model could help identify CAPS in high-risk patients, achieve early recognition and intervention to improve prognosis.

Characteristics and risk factors of retinal vasculopathy in antiphospholipid syndrome.

BACKGROUND: Retinal vasculopathy including retinal artery occlusion (RAO) or retinal vein occlusion (RVO) was recently found to occur more frequently in antiphospholipid syndrome (APS) patients than non-APS patients. This study aims to investigate the clinical manifestation and risk factors of retinal vasculopathy among APS patients. METHODS: In this single-center prospective cohort study, we evaluated APS patients with or without retinal vasculopathy during 2018-2020 at Peking Union Medical College Hospital. Clinical variables were compared, and a logistical regression model was built to explore risk factors. Hierarchical cluster analysis using Euclidean distances was applied to identify clusters of variables. RESULTS: A total of 310 APS patients (67.4% female, mean age 38.1 years) were included, of whom 18 (5.8%) were diagnosed with retinal vasculopathy (9 with RVO and 9 with RAO). No significant differences were found among most demographic characteristics, clinical manifestations, or antibody profiles. APS-related heart valve disease (odds ratio OR 13.66, 95% confidence interval CI 4.55-40.98), APS nephropathy (OR 12.77, 95% CI 4.04-40.35), and thrombocytopenia (OR 2.63, 95% CI 1.01-6.89) were predictive of retinal vasculopathy. APS-related heart valve disease and nephropathy were also found to be statistically significant predictors in multivariate logistical regression analysis. Non-criteria manifestations were aggregated with retinal vasculopathy from a cluster analysis of variables. CONCLUSION: Patients with APS-related heart valve disease and nephropathy suffered a higher risk of retinal vasculopathy. The underlying mechanisms of aPL-associated retinal vasculopathy may involve thrombotic microangiopathy, leading to poor prognosis and therapeutic changes.

Experiment and simulation of flexible CNT/SA/PDMS electromagnetic shielding composite.

Flexible electromagnetic shielding composites have a great potential for wide range applications. In this study, two flexible composites were produced by plating Ni nanoparticles on carbon nanotubes (CNTs) or infiltrating carbon nanofibers/polydimethylsiloxane (CNF/PDMS) polymer into CNT/sodium alginate (CNT/SA) sponge skeleton (CNT/SA/CNF/PDMS composites). The composites are tested under the X band in the frequency range of 8.2 - 12.4 GHz, the electromagnetic interference shielding effectiveness (EMI-SE) values of the above two composites are almost as twice as that of CNT/SA/PDMS composite at a same CNT loading. Introducing nano-sized Ni particles on CNT improved the microwave absorption capacity of the composite, while adding CNF on the PDMS matrix enhanced the conductivity of these composites. Under 10% strain, both flexible composites show stable conductivity. Simulation and calculation results shown that increasing the cladding rate of Ni nanoparticles on the surface of CNT, reducing the average size of Ni particles, and increasing the loading of CNF in PDMS matrix can significantly improve conductivity and then EMI performance of the materials. All of these could benefit for the design of flexible electromagnetic shielding composites.

Sirolimus for patients with connective tissue disease-related refractory thrombocytopenia: a single-arm, open-label clinical trial.

OBJECTIVES: Connective tissue disease-related thrombocytopenia (CTD-TP) is a problematic disorder in clinical practice. Because the first-line therapy of glucocorticoid and/or immunosuppressants is not effective for refractory cases, alternative treatment approaches are urgently needed. The present study investigated the efficacy and safety of sirolimus in refractory CTD-TP patients. METHODS: This single-centre, single-arm, phase II study enrolled 20 refractory CTD-TP patients between September 2017 and September 2018 (registered on ClinicalTrials.gov: NCT03688191). Oral sirolimus administration was dose-adjusted to maintain a therapeutic range of 6-15 ng/ml for 6 months. The primary endpoints were partial and complete remission rates at 6 months. RESULTS: Twelve (60%) patients achieved the primary end point with a 50% complete remission rate after 6 months. Among the 14 SLE patients, the overall response rate was 71.4%, with a complete remission rate of 64.3%. None of the primary Sjögren's syndrome cases responded to sirolimus. There was no significant difference in baseline clinical characteristics or lymphocyte subpopulations between responders and non-responders. No severe side effect was detected during the study. CONCLUSION: Sirolimus is an effective and safe treatment option for refractory CTD-TP patients. TRIAL REGISTRATION: https://clinicaltrials.gov, NCT03688191.

Ventricular arrhythmia predicts poor outcome in polymyositis/dermatomyositis with myocardial involvement.

OBJECTIVE: Myocardial involvement (MCI) is known to increase morbidity and mortality in polymyositis (PM) and dermatomyositis (DM). This study aims to investigate whether complicating with ventricular arrhythmia (VA) predicts poor outcomes in patients with PM/DM-related myocardial involvement (PM/DM-MCI). METHODS: We reviewed all PM/DM-MCI patients admitted to Peking Union Medical College Hospital from October 1997 to April 2019. VA and the other possible risk factors for the composite endpoint, including death from any cause and rehospitalization for cardiac causes, were analyzed. RESULTS: A total of 75 PM/DM-MCI patients (44 PM and 31 DM) were enrolled, of which 27 (36%) met the composite endpoint during a median follow-up of 24 months. Independent prognostic factors for the composite endpoint include VA [HR 4.215, 95% CI (1.737, 10.230)], NT-proBNP > 3415 pg/ml [HR 2.606, 95% CI (1.203, 5.646)], interstitial lung disease [HR 2.688, 95% CI (1.209, 5.978)], and anti-cardiac remodelling therapy [HR 0.302, 95% CI (0.115, 0.792)]. The 3-year event-free survival rate of patients without VA was significantly higher than that of patients with VA (63.3% vs 40.7%, P = 0.034). Skin lesions [OR 0.163, 95% CI (0.051, 0.523)] and positive antimitochondrial antibody [OR 3.484, 95% CI (1.192, 10.183)] were independent predictors of VA. CONCLUSION: VA provides prognostic insights for PM/DM-MCI patients and predicts poor outcome. Polymyositis and positive antimitochondrial antibody are closely associated with the presence of VA in PM/DM-MCI.

The long-term prognosis of pneumomediastinum associated with dermatomyositis: a two-centre retrospective cohort study.

OBJECTIVES: Pneumomediastinum (PnM) is a rare but life-threatening complication of DM. The present study aims to characterize the long-term prognosis and prognostic factors of DM-associated PnM. METHODS: Inpatients with DM-associated PnM were retrospectively enrolled from two tertiary referral centres for rheumatic disease. The enrolled patients were divided into survivors or non-survivors. Information about the demographics, clinical manifestations, CT scan features, laboratory findings and outcomes were collected from their medical records. A least absolute shrinkage and selection operator regularized Cox regression model was used to select the most relevant factors. Prognosis was analysed using a Kaplan-Meier curve. A Cox proportional hazards model was used to identify independent predictive factors for long-term survival. RESULTS: A total of 62 patients (26 women) with DM-associated PnM were enrolled. The mean age was 44.3 years (s.d. 11.7). The median follow-up duration was 17 days (quartiles 7, 266.5). Thirty-five patients died during follow-up. The survival rates were 75.4% at 1 week, 46.2% at 3 months and 41.9% at 1 year. The Cox proportional hazards model identified the development of fever [hazard ratio (HR) 3.23 (95% CI 1.25, 8.35), P = 0.02] and a decrease in the number of lymphocytes [HR 2.19 (95% CI 1.10, 4.39), P = 0.03] as independent risk factors for death. CONCLUSION: The results suggest poor overall survival among patients with DM-associated PnM. Survival during the first 3 months is crucial for long-term survival. Meanwhile, the development of fever and a decrease in the number of lymphocytes were associated with long-term mortality. Early recognition and prompt treatment of this high-risk group of DM patients is therefore important.

Aberrant expression of cell-free nucleosomes in dermatomyositis/polymyositis.

Nucleosomes are typically located intracellularly, and extracellular levels of nucleosomes indicated the degree of cell death. We postulated aberrant nucleosomes expression in dermatomyositis (DM) and polymyositis (PM). To assess the aberrant expression of circulating nucleosomes in DM and polymyositis. 76 consecutive DM and PM patients from 1 September 2017 to 31 October 2018 were enrolled in this study, in addition to 20 healthy controls. The levels of circulating nucleosomes, with 16 kinds of detectable myositis-specific antibodies (MSAs) were detected in IIMs patients using enzyme-linked immunosorbent assay kit (ELISA). Receiver operating characteristic (ROC) curve analysis was performed for evaluating the ability of this candidate marker for detecting DM/PM. The results showed that the levels of circulating nucleosomes in DM/PM patients were significantly higher than that in normal individuals. Specifically, elevated levels of nucleosomes were associated with MDA5 Ab, ARS, and TIF1γAb. In addition, elevated levels of circulating nucleosomes correlated with skin eruption. This study has evidenced nucleosomes as a potential new biomarker of DM/PM. Aberrant nucleosomes expression occurs in myositis patients and the difference in nucleosomes expression between patients with and without skin eruption is statistically significant. A unique expression profile of elevated serum nucleosomes was detected in DM/PM-MDA5 Ab(+), ASS, and TIF1γAb(+).

Analysis of myositis autoantibodies in Chinese patients with cancer-associated myositis.

BACKGROUND: Cancer-associated myositis (CAM) has poor prognosis and causes higher mortality. In general, myositis-specific autoantibodies (MSAs) and myositis-associated autoantibodies (MAAs) have been shown to be useful biomarkers for its diagnosis. METHODS: In the present study, focus was given in assessing the presence, prevalence, and diagnostic values of myositis autoantibodies in Chinese patients diagnosed with CAM. The sera collected from 49 CAM patients, 108 dermatomyositis/polymyositis (DM/PM) patients without cancer, 105 disease controls, and 60 healthy controls were detected for the presence of 16 autoantigens (Jo-1, OJ, EJ, PL-7, PL-12, MDA5, TIF1γ, Mi-2α, Mi-2ß, SAE1, NXP2, SRP, Ku, PM-Scl75, PM-Scl100, and Ro-52) using a commercial Euroline assay. RESULTS: The frequency of anti-TIF1γ was significantly higher in CAM patients than in DM/PM patients without cancer (46.9% vs 14.8%, P < .001). Importantly, the sensitivity and specificity for this MSA were 46.9% and 85.2%, respectively. These helped to differentiate CAM patients from DM/PM patients without cancer. However, there was no difference in other MSAs and MAAs between CAM and DM/PM patients without cancer. CONCLUSION: The present study indicates that anti-TIF1γ levels can serve as important biomarkers for CAM diagnosis and help in distinguishing between CAM and DM/PM patients without cancer.

Simultaneous Multislice Accelerated Diffusion Tensor Imaging of Thigh Muscles in Myositis.

OBJECTIVE: Diffusion tensor imaging (DTI) has long been proposed as a potential tool for quantitatively evaluating muscle lesions of dermatomyositis (DM) and polymyositis (PM), but adapting DTI to thigh muscles requires minimizing acquisition time. We investigated the clinical feasibility of using SMS-EPI-DTI (simultaneous multislice [SMS] accelerated echo planar imaging [EPI] DTI) to image and analyze the anisotropic diffusion characteristics of thigh muscles in patients with DM or PM. SUBJECTS AND METHODS: Both thighs of 20 patients (seven patients with DM and 13 patients with PM) and 10 healthy control subjects were prospectively scanned using SMSEPI-DTI. Tractographic images and DTI-derived parameters, including fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values and three eigenvalues (λ1, λ2, and λ3), were obtained from four selected muscles (vastus medialis, vastus intermedius, adductor magnus, and semimembranosus) and were analyzed. After Bonferroni correction, p < 0.017 (0.05/3) was considered to denote statistical significance. RESULTS: SMS-EPI-DTI allowed imaging of both thighs of patients with DM or PM and healthy control subjects within approximately 5 minutes. For each of the four measured muscles, FA values for patients with edematous muscles were lower than those for patients with unaffected muscles and healthy control subjects with normal muscles (p < 0.017 for all). The ADC and λ1, λ2, and λ3 values of edematous muscles were significantly higher than those for patients with unaffected muscles and healthy control subjects (p < 0.017 for all). Unaffected muscles of patients and healthy control subjects were similar in terms of all parameters (p > 0.017 for all). CONCLUSION: SMS-EPI-DTI is clinically feasible for imaging thigh muscles and quantitatively evaluating edematous muscles of patients with DM or PM.

Clinical characteristics of immunoglobulin G4-related disease: a prospective study of 118 Chinese patients.

OBJECTIVE: To characterize the clinical features of IgG4-related disease (IgG4-RD) in China. METHODS: A prospective cohort study of IgG4-RD was carried out in Peking Union Medical College Hospital between 2011 and 2013. Patients with newly diagnosed IgG4-RD were enrolled. RESULTS: A total of 118 patients with IgG4-RD were enrolled, including 82 males and 36 females, aged 53.1 (s.d. 13.6) years. The most common symptom at onset was lacrimal gland swelling (38/32.2%). A range of organs were involved: 77 patients (65.3%) had lymphadenopathy, 76 (64.4%) had sialadenitis, 60 (50.8%) had dacryoadenitis, 45 (38.1%) had autoimmune pancreatitis, 32 (27.1%) had pulmonary involvement, 31 (26.3%) had periaortitis/retroperitoneal fibrosis, 29 (35.4% of male patients) had prostatitis and 29 (24.6%) had renal involvement. In addition, there were 21 (17.8%) cases of sclerosing cholangitis, 15 (12.7%) of sinusitis and 10 (8.5%) of inflammatory pseudotumour. Uncommon manifestations included mediastinal fibrosis, skin involvement, sclerosing thyroiditis, hypophysitis, orchitis and colitis. Multiple organ involvement was observed in 93 patients, whereas only 4.2% had only a single organ involved. A history of allergy was reported in 73 (61.9%) patients. The serum IgG4 level was elevated in 97.5% and was correlated with the number of organs involved. Most patients were treated with glucocorticoids alone or in combination with immunosuppressive drugs, and the majority usually improved within 3 months. CONCLUSION: IgG4-RD is a systemic inflammatory and sclerosing disease. Parotid and lacrimal involvement (formerly called Mikulicz's disease), lymphadenopathy and pancreatitis are the most common manifestations. Patients with IgG4-RD showed favourable responses to treatment with glucocorticoids and immunosuppressive agents.

[Clinical characteristics of patients with relapsing polychodritis].

OBJECTIVE: To analyze the clinical characteristics of relapsing polychodritis (RP). METHODS: Clinical features and laboratory data of 131 patients with RP were analyzed retrospectively. RESULTS: The average age at onset was (44 ± 14) years (ranging from 9 to 76). Male to female ratio was 1.22:1. The most common onset symptom was respiratory system symptom (61.8%), followed by auricle lesions (16.0%), articular cartilage (15.3%), ocular region (7.6%), internal ear system (5.3%), nasal cartilages (4.6%), skin (2.3%) and nervous system (0.8%). During the whole course of the disease, 81.7% of the patients endured a respiratory system involvement; 77.9% and 56.5% of the patients suffered joint symptoms and nasal cartilages lesions, respectively; the involvement of auricle lesions, ocular region and internal ear system were 54.2%, 35.1% and 33.6%. Comparatively, the occurrence rates of skin lesion (10.7%), neurologic disorder (9.2%) and kidney system lesions (1.5%) were low. Analyzing of the laboratory examination data showed that 38.2% and 43.5% of the patients had an increase in white blood count (WBC) and platelet, 86.3% and 82.4% patients showed raised erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) values. CONCLUSIONS: RP is a multi-system involvement disease, which has complicated clinical manifestations. Respiratory tract is the most common site involved, and respiratory system involvement is a prediction of unfavourable prognosis.

[The prevalence and clinical significance of arthritis in patients with systemic sclerosis].

OBJECTIVE: To explore the prevalence and independent influencing factors of arthritis in Chinese patients with systemic sclerosis (SSc). METHODS: A total of 248 SSc patients were enrolled in this prospective cross-sectional study in Peking Union Medical College Hospital. Demographic, clinical and laboratory data were compared in arthritis group and non-arthritis group. RESULTS: Of 248 Chinese SSc patients, mean age of onset was (37.1 ± 13.7) years old and disease duration was (7.4 ± 5.2) years. Overall prevalence of arthritis was 41.1% (102/248). The presence of arthralgia(95.1% vs 15.1%), muscle weakness (38.2% vs 24.7%), short of breath (60.8% vs 45.2%), and intestinal lung disease (64.7% vs 49.3%) occurred more frequently in patients with arthritis than those without arthritis (P < 0.05). The elevation of C reactive protein, anti-Sm and anti-cyclic citrullinated peptide were more common in arthritis group than in non-arthritis group (61.4% vs 43.9%, 11.4% vs 2.5% and 28.1% vs 2/16, respectively). There were no obvious differences in the Rodnan score, digital ulcers, pulmonary arterial hypertension, and six-minute walk test between two groups (P > 0.05). CONCLUSION: This study reveals the significant prevalence of arthritis in a large cohort of SSc patients in China. Compared to non-arthritis patients, the SSc patients with arthritis have a more severe inflammation reaction and a higher rate of intestinal lung disease.

Global trends in research of melanoma differentiation-associated gene 5: a bibliometric analysis from 2002 to 2022.

BACKGROUND: Melanoma differentiation-associated gene 5 (MDA5), as a cytoplasmic sensor for viral double-stranded RNAs, has received increasing attention in recent years. Although considerable headway has been made on the functional role of MDA5 in antiviral immunity and autoimmune disease, the available literature is insufficient to assess the vast field. METHODS: This study performed a bibliometric analysis to investigate current hotspots in the global scientific output of MDA5 over the past two decades. Related publications and recorded information from 2002 to 2022 in the Web of Science Core Collection (WoSCC) database were retrieved. VOSviewer and CiteSpace were used for quantitative evaluation and visualization. RESULTS: A total of 2267 original articles and reviews were obtained, and the annual number of publications related to MDA5 was increasing rapidly. China has published the most papers, while the USA was the most influential country with the most citations and the highest H-index. The Chinese Academy of Sciences, the United States Department of Health and Human Services, and the Journal of Virology were the most prolific research affiliation, funding source, and journal, respectively. Fujita T (Kyoto University) was the most productive author with the highest H-index and had close cooperation with Kato H and Yoneyama M. The keywords "RIG-I," "MDA5," "innate immunity," "double-stranded-RNA," and "recognition" had the highest frequency, while "dermatomyositis" as well as "autoantibody" seemed to be the emerging hotspots. CONCLUSION: This study comprehensively demonstrated the research frontiers of MDA5 and will provide a useful resource for scholars to conduct future decisions. KEY POINTS: We conducted the first in-depth survey of the research frontiers on melanoma differentiation-associated gene 5 (MDA5) over the past two decades via bibliometric analysis. We found that many early breakthroughs have been made in the mechanism of MDA5-mediated antiviral immune responses, and the role of MDA5 in autoimmune and autoinflammatory diseases has raised the recent concern. We identified that the virus infection-associated pathogenesis and effective therapeutic strategy of anti-MDA5 antibody-positive dermatomyositis will remain the hotspots in the future.

Microarray analysis of microrna expression in peripheral blood mononuclear cells of patients with polymyositis and dermatomyositis.

Background and Objectives: MicroRNAs (miRNAs) represent a new class of biomarkers in the context of connective tissue disorders. The miRNA expression profiles in peripheral blood mononuclear cells (PBMCs) of patients with polymyositis (PM) and dermatomyositis (DM) have not been fully elucidated. The objective is to investigate miRNAs expression profile in PBMCs of patients with PM/DM. Methods: Microarray technology was used to identify differentially expressed miRNAs in PBMCs obtained from 6 untreated PM/DM patients and 3 healthy controls (HCs). TaqMan-based stem-loop real-time PCR detection was used for validation in a cohort of 34 PM/DM patients and 20 HCs. Results: Microarray analysis revealed 38 differentially expressed miRNAs (24 up-regulated and 14 down-regulated) in PM/DM patients compared to HCs. Four miRNAs (miR-320a, miR-335-3p, miR-34a-5p and miR-454-3p) were chosen for real-time PCR validation. The expression of miR-34a-5p was significantly upregulated in PM/DM group (P < 0.05). In subgroup analysis, miR-34a-5p was significantly upregulated in interstitial lung disease (ILD) group and DM group (P < 0.001). The level of SIRT1, a validated target of miR-34a, was significantly lower in PBMCs of PM/DM patients compared with HCs. Conclusions: MiR-34a-5p may potentially participate in the pathogenesis of PM/DM through SIRT1, and may serve as a potential new biomarker for PM/DM-ILD.