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Objective Idiopathic inflammatory myopathies (IIMs) are autoimmune disorders significantly impacting skeletal muscles; however, the precise correlation between muscle magnetic resonance imaging (MRI) findings, muscle pathology, disease subtypes and clinical characteristics remains uncertain. Thus, we investigated the association of muscle MRI findings in IIMs with muscle pathology and clinical features. Methods New-onset IIM patients underwent proximal upper and/or lower limb muscle MRI. Patterns of muscle oedema on MRI were categorised into fascial, honeycomb, peripheral, foggy, dense, or coarse dot patterns and compared with inflammatory cell infiltration sites in corresponding muscle biopsies. The incidence of MRI patterns was examined in patient subgroups using myositis-specific antibodies (MSAs) and 2017 EULAR/ACR classification criteria. Univariate and multivariate analyses were conducted to determine the odds ratios (ORs) of MRI findings for clinical characteristics. Results Fifty-six of 85 patients underwent muscle biopsy. Foggy, honeycomb and fascial patterns at biopsy sites correlated with inflammatory cell infiltration in the endomysium (OR 11.9, P  = 0.005), perimysium (OR 6.0, P  = 0.014) and fascia (OR 16.9, P  < 0.001), respectively. Honeycomb and foggy patterns were characteristic of patients with anti-TIF1γ or anti-Mi2 antibodies and MSA-negative dermatomyositis, and those with anti-SRP or anti-HMGCR antibodies and MSA-negative polymyositis (PM), respectively. The honeycomb pattern positively correlated with malignancy (OR 6.87, P  < 0.001) and Gottron sign (OR 8.05, P  = 0.002); the foggy pattern correlated with muscle weakness (OR 11.24, P  = 0.005). The dense dot pattern was associated with dysphagia (OR 6.27, P  = 0.006) and malignancy (OR 8.49, P  = 0.002). Conclusion Muscle MRI holds promise in predicting muscle pathology, disease subtypes and clinical manifestations of IIMs. [ABSTRACT FROM AUTHOR]

Objectives To assess the ability of dual-energy X-ray absorptiometry (DXA) and hand-grip dynamometer to measure damage in inflammatory myopathies (IM). Methods Forty adult IM patients with a disease duration ≥12 months, low or no disease activity for ≥6 months, were prospectively enrolled. Thirty healthy age and sex-matched volunteers were enrolled as controls. Whole-body DXA and hand-grip dynamometer were used to measure muscle mass, grip strength and diagnose sarcopenia (EWGSOP2 criteria). Relationships between the results of strength in 12 muscles, functional tests, patient-reported disability, IMACS damage score, and history of the disease were assessed. The serum levels of potential molecular actors in the damage were measured. Results DXA and grip strength measurements took ≤20 min. Both muscle mass and grip strength were decreased in IM patients vs volunteers (−10% and −30%, respectively) with a dispersion that varied widely (interquartile range −24.3% to +7.8% and −51.3% to −18.9%, respectively). Muscle mass and grip strength were non-redundantly correlated (r up to 0.6, P  = 0.0001) with strength in 14 muscles (manual muscle test and hand-held dynamometer), functions (of limbs, respiratory and deglutition muscles), patient-reported disability, damage (extension and severity in muscular and extra-muscular domains) and blood levels of several myokines. Seven IM patients (17.5%) were sarcopenic. They had the worst damage, impaired functions, disability and history of severe myopathy. Decreased irisin and osteonectin levels were associated with sarcopenia (area under the curve 0.71 and 0.80, respectively). Conclusion DXA and hand-grip dynamometer are useful tools to assess damage in IM. Irisin and osteonectin may play a role in IM damage pathogenesis. [ABSTRACT FROM AUTHOR]

Objectives Myositis-specific and associated autoantibodies are important biomarkers in routine clinical use. We assessed local testing performance for myositis autoantibodies by comparing line immunoassay (LIA) to protein radio-immunoprecipitation and identifying clinical characteristics associated with each myositis autoantibody in the MyoCite cohort. Methods Serum samples from patients within the MyoCite cohort, a well-characterized retro-prospective dataset of adult and juvenile idiopathic inflammatory myopathy (IIM) patients in Lucknow, India (2017–2020), underwent LIA at Sanjay Gandhi Postgraduate Institute of Medical Science (SGPGIMS), Lucknow. Immunoprecipitation of 147 IIM patients' serum samples (125 adult-onset, 22 juvenile-onset) was conducted at the University of Bath, with researchers blind to LIA results. LIA performance was assessed against immunoprecipitation as the reference standard, measuring sensitivity, specificity and inter-rater agreement. Univariate and multivariate logistic regression determined clinical associations for specific myositis-specific autoantibodies. Results Immunoprecipitation identified myositis autoantibodies in 56.5% (n  = 83) of patient samples, with anti-Jo1 (n  = 16; 10.9%) as the most common, followed by anti-MDA5 (n  = 14, 9.5%). While LIA showed good agreement for anti-Jo1, anti-PL7 and anti-PL12 (Cohen's κ 0.79, 0.83 and 1, respectively), poor agreement was observed in other subgroups, notably anti-TIF1γ (Cohen's κ 0.21). Strongly positive samples, especially in myositis-specific autoantibodies, correlated more with immunoprecipitation results. Overall, 59 (40.1%) samples exhibited non-congruence on LIA and immunoprecipitation, and κ values for LIAs for anti-TIF1γ, anti-Ku, anti-PmScl, anti-Mi2 and anti-SAE ranged between 0.21 and 0.60. Conclusion While LIA reliably detected anti-Jo1, anti-PL7, anti-PL12, anti-MDA5 and anti-NXP-2, it also displayed false positives and negatives. Its effectiveness in detecting other autoantibodies, such as anti-TIF1γ, was poor. [ABSTRACT FROM AUTHOR]

ObjectivesPatients with idiopathic inflammatory myopathies (IIM) have severe vascular involvement, which contributes to disease morbidity and mortality. Paraoxonase-1 (PON1) is a high-density lipoprotein (HDL) associated protein that protects the vascular endothelium from oxidative injury and damage. The current work assessed the functional and genetic determinants of PON1 activity in IIM patients.MethodsA total of 184 IIM patients and 112 healthy controls (HC) were included. PON1 enzyme activity was assessed by paraoxonase, arylesterase and lactonase assays, and the Q192R PON1 single nucleotide polymorphism (SNP) was analysed. Multivariate regression models examined associations of PON1 activity with IIM diagnosis and myositis disease outcomes.ResultsThe arylesterase and lactonase activities of PON1 were significantly lower in IIM patients compared with HC. Higher myositis disease activity, the presence of severe IIM-associated interstitial lung disease (ILD), and the presence of MDA5 or anti-synthetase antibodies were significantly associated with lower PON1 activity. The PON1 Q192R polymorphism was strongly linked to the paraoxonase activity of PON1 in IIM, and patients with the PON1 QQ genotype had better IIM disease outcomes compared with patients with the QR or RR genotypes.ConclusionsThe arylesterase and lactonase activities of PON1 are significantly impaired in IIM patients compared with HC, and inversely associate with IIM disease activity and the presence of severe ILD. The PON1 QQ genotype associates with more favourable disease outcomes in IIM patients. Large prospective studies are needed to further evaluate the role of PON1 and PON1 genetic polymorphisms in the development and propagation of IIM and IIM-ILD.

Polymyositis (PM) and dermatomyositis (DM) are rare idiopathic inflammatory myopathies (IIM). Myocardial involvement in patients with IIM is an unfavorable prognostic factor and one of the most common cause of mortality in this group of patients. The purpose of this review is the presentation of current knowledge on cardiovascular manifestations observed in IIM. Published in English data until December 2021 were selected. Clinical symptoms suggesting cardiac involvement are non-specific and require a differential diagnosis in accordance with cardiological guidelines. Troponin I is specific to cardiac injury and should be preferred to other markers to evaluate the myocardium in IIM. Abnormalities in electrocardiography are common in IIM , especially non-specific changes of ST-T segment. In standard echocardiography left ventricular diastolic dysfunction is reported frequently. New diagnostic technologies can reveal clinically silent myocardial abnormalities. However, prognostic value of subclinical impairment of myocardial function require further studies.

Objective The ACR-EULAR Myositis Response Criteria (MRC) were developed as a composite measure using absolute percentage change in six core set measures (CSMs). We aimed to further validate the MRC by assessing the contribution of each CSM, frequency of strength vs extramuscular activity improvement, representation of patient-reported outcome measures (PROM), and frequency of CSM worsening. Methods Data from adult dermatomyositis/polymyositis patients in the rituximab (n  = 147), etanercept (n  = 14), and abatacept (n  = 19) trials, and consensus patient profiles (n  = 232) were evaluated. The Total Improvement Score (TIS), number of improving vs worsening CSMs, frequency of improvement with and without muscle-related CSMs, and contribution of PROM were evaluated by MRC category. Regression analysis was performed to assess contribution of each CSM to the MRC. Results Of 412 adults with dermatomyositis/polymyositis, there were 37%, 24%, 25%, and 14% with no, minimal, moderate, and major MRC improvement, respectively. The number of improving CSMs and absolute percentage change in all CSMs increased by improvement category. In minimal-moderate improvement, only physician-reported disease activity contributed significantly more than expected by MRC. Of patients with at least minimal improvement, 95% had improvement in muscle-related measures and a majority (84%) had improvement in PROM. Patients with minimal improvement had worsening in a median of 1 CSM, and most patients with moderate-major improvement had no worsening CSMs. Physician assessment of change generally agreed with MRC improvement categories. Conclusion The ACR-EULAR MRC performs consistently across multiple studies, further supporting its use as an efficacy end point in future myositis therapeutic trials. [ABSTRACT FROM AUTHOR]

Objective Diagnostic muscle biopsies are routinely immunostained for major histocompatibility complex class I (MHC-I) protein. In this study we analysed the prevalence and patterns of MHC-I immunostaining in biopsies from patients with different types of myopathies and neurogenic disorders. Methods All 357 diagnostic muscle biopsies processed at the Johns Hopkins Neuromuscular Pathology Laboratory from August 2013 to January 2017 were immunostained for MHC-I. The prevalence and patterns of MHC-I immunostaining were compared between patients with histologically normal muscle biopsies (n  = 31), idiopathic inflammatory myopathies (IIMs; n  = 170), non-inflammatory myopathies (n  = 60) and neurogenic disorders (n  = 96). Results MHC-I immunostaining was abnormal in most patients with DM (98%), sporadic IBM (sIBM; 100%), immune-mediated necrotizing myopathy (IMNM; 100%) and polymyositis (77%). In contrast, MHC-I immunostaining was less frequently present in non-inflammatory myopathies (32%) or neurogenic disorders (30%). Overall, abnormal MHC-I immunostaining had a sensitivity of 0.95 and a specificity of 0.82 for diagnosing IIMs. A focal MHC-I staining pattern was associated with IMNM, whereas a global pattern was more prevalent in sIBM and a perifascicular pattern was significantly more common in dermatomyositis. Among 18 DM biopsies without perifascicular atrophy, 50% had a perifascicular MHC-I staining pattern. Sarcoplasmic upregulation staining was more common than sarcolemmal staining across all groups. Conclusion MHC-I immunostaining was useful to distinguish IIMs from non-inflammatory myopathies or neurogenic disorders. Of note, a perifascicular MHC-I staining pattern was present only in those with DM, including half of those without perifascicular atrophy; many of these biopsies may not otherwise have been diagnostic for DM. [ABSTRACT FROM AUTHOR]

Introduction Muscle enzymes are an indicator of ongoing muscle damage and disease activity in patients with idiopathic inflammatory myopathy. Although platelet-related parameters have been shown to be useful as markers of disease activity in autoimmune diseases, the relationship between platelet distribution width (PDW) and disease activity has not been previously studied in polymyositis. We aimed to determine the relationship between PDW and disease activity in patients with polymyositis. Material and methods Twenty-seven patients with polymyositis and thirty healthy controls were included in the study. Disease activity was evaluated using the myositis disease activity assessment Visual Analogue Scale (MYOACT) and the Myositis Intention to Treat Index (MITAX). The relationship between PDW and disease activity was evaluated using Pearson’s or Spearman’s correlation and reliability was assessed using correlation coefficients. Results The mean platelet volume (MPV) and plateletcrit (PCT) were significantly higher and PDW was significantly lower in patients with polymyositis compared to the control group. The mean PDW levels were lower in patients with constitutional symptoms and arthralgia/arthritis (p < 0.005). Although PDW levels were lower in patients with mechanical hand, lung involvement, or dysphagia compared to patients without, there was no statistically significant difference between them. Platelet distribution width was found to be negatively correlated with disease activity. Conclusions We found that PDW was negatively correlated with MYOACT and MITAX, widely used tools in assessing the disease activity of polymyositis. Based on this, PDW may be utilized as a non-invasive potential index to assess disease activity in patients with polymyositis.

Objectives To document the work situation, the work ability and the expectation of returning to work among adult patients with systemic autoimmune myopathies (SAMs), and to identify the factors associated with each of these outcomes. Methods Cross-sectional study. The work situation (performing paid work vs out of work) was ascertained via a structured questionnaire. For those who were working, we applied the Work Ability Index (WAI; scale 7–49); and for those who were out of work, we applied the Return-to-Work Self-Efficacy questionnaire (RTW-SE; scale 11–66). Results Of the 75 patients with SAMs included, 33 (44%) were doing paid work and 42 (56%) were out of work. The work situation was independently associated with physical function, assessed by the Health Assessment Questionnaire-Disability Index (HAQ-DI). A 1-point increase in the HAQ-DI (scale 0–3) decreased the chance of doing paid work by 66% (95% CI: 0.16, 0.74; P  = 0.007). Patients performing paid work had a mean WAI of 33.5 (6.9). The following variables were associated with a decrease in the WAI score in the regression model: female sex (−5.04), diabetes (−5.94), fibromyalgia (−6.40), fatigue (−4.51) and severe anxiety (−4.59). Among those out of work, the mean RTW-SE was 42.8 (12.4). Cutaneous manifestations and >12 years of education were associated with an average increase of 10.57 and 10.9 points, respectively, in the RTW-SE. A 1-point increase in the HAQ-DI decreased the RTW-SE by 4.69 points. Conclusion Our findings highlight the poor work participation in a well-characterized sample of working-age patients with SAMs. Strategies to improve work-related outcomes in these patients are urgently needed. [ABSTRACT FROM AUTHOR]

Objectives To assess the efficacy and safety of branched chain amino acids (BCAAs) in the treatment of PM/DM prior to official approval of their use in Japan. Methods Treatment naïve adults with PM/DM were enrolled in a randomized, double-blind trial to receive either TK-98 (drug name of BCAAs) or placebo in addition to conventional treatment. After 12 weeks, patients with an average manual muscle test (MMT) score <9.5 were enrolled in an open label extension study for a further 12 weeks. The primary endpoint was the change of the MMT score at 12 weeks. The secondary endpoints were the clinical response and the change of functional index (FI). Results Forty-seven patients were randomized either to the TK-98 (n  = 24) or placebo (n  = 23) group. The changes of MMT scores at 12 weeks were 0.70 (0.19) [mean (s. e. m.)] and 0.69 (0.18), respectively (P  = 0.98). Thirteen patients from the TK-98 group and 12 from the placebo group were enrolled in the extension study. The MMT scores in both groups improved similarly. The increase of the FI scores of the shoulder flexion at 12 weeks was significantly greater in the TK-98 group [27.9 (5.67) vs 12.8 (5.67) for the right shoulder flexion, and 27.0 (5.44) vs 13.4 (5.95) for the left shoulder; P  < 0.05]. Frequencies of adverse events up to 12 weeks were similar. Conclusion BCAAs showed no effect on the improvement of the muscle strength evaluated by MMT and the clinical response. However, they were partly effective for improving dynamic repetitive muscle functions. Trial registration UMIN-CTR Clinical Trial, https://center6.umin.ac.jp/ , UMIN000016233 [ABSTRACT FROM AUTHOR]

Objectives In the present study, we aimed to assess the prevalence and clinical significance of anti-Ro52 antibodies in a cohort of patients with idiopathic inflammatory myopathy-associated interstitial lung disease (IIM-ILD) with different myositis-specific autoantibodies (MSAs). Methods A cohort of 267 IIM-ILD patients, including 62 patients with PM, 126 patients with DM and 79 patients with clinically amyopathic DM (CADM) were retrospectively analysed in this study. Clinical and laboratory findings, pulmonary function tests (PFTs), HRCT patterns and treatment information were compared between patients with and without anti-Ro52 antibodies. The association between prognosis and anti-Ro52 antibodies was also evaluated based on different MSA subgroups. Results Anti-Ro52 antibodies were more frequent in patients with anti-MDA5 (62.1%, P  < 0.01) and anti-Jo1 (64.9%, P  < 0.01) antibodies than in those with other MSAs. The proportion of patients with anti-Jo1 antibodies was higher in the anti-Ro52 antibody-positive group than in the anti-Ro52 antibody-negative group. Patients with anti-Ro52 antibodies were more likely to exhibit the Gottron sign than the anti-Ro52 antibody-negative group (P  < 0.001). Furthermore, it was a predictive factor for rapid progression interstitial lung disease (RP-ILD) (P  = 0.001) and was also associated with a higher mortality rate (log-rank test, P  = 0.001). Furthermore, RP-ILD was more frequently exhibited in anti-MDA5- and anti-Ro52-positive patients. Moreover, anti-Ro52 antibody positivity was closely associated with a higher mortality rate in anti-MDA5-ILD patients (log-rank test, P  < 0.05). Conclusions Anti-Ro52 antibodies were highly prevalent in patients with anti-MDA5 and anti-Jo1 antibodies. Within all patients with IIM-ILD, those with anti-Ro52 autoantibodies had a higher frequency of RP-ILD and a poorer prognosis, especially in the anti-MDA5 antibody subgroup. [ABSTRACT FROM AUTHOR]

Objectives Infections including tuberculosis (TB) are a leading cause of morbidity and mortality in idiopathic inflammatory myopathies (IIM). We systematically reviewed the prevalence of mycobacterial infections in patients with IIM. Methods We screened PUBMED, EMBASE and SCOPUS databases and conference abstracts (2015–20) for original articles using Covidence. Pooled estimates of prevalence were calculated. Results Of 83 studies (28 cohort studies, two case control and 53 case reports), 19 were analysed. Of 14 043 IIM patients, DM (54.41%) was the most common subset among TB. Most studies were from Asia with high prevalence (5.86%, 2.33%–10.60%). Pooled prevalence of mycobacterial infections among IIM was 3.58% (95% CI: 2.17%, 5.85%, P  < 0.01). Disseminated and extrapulmonary forms (46.58%; 95% CI: 39.02%, 54.31%, P  = 1.00) were as common as pulmonary TB (49.07%; 95% CI: 41.43%, 56.75%, P  =0.99) both for I 2=0. Muscle involvement, an otherwise rare site, was frequently seen in case reports (24.14%). M. tuberculosis (28.84%) was the most common pathogen followed by Mycobacterium avium complex (3.25%). Non-tuberculous mycobacteria were less common overall (6.25; 95% CI: 3.49%, 10.93%) I 2=0, P  =0.94. Subgroup analysis and meta-regression based on high vs low TB regions found prevalence 6.61% (2.96%, 11.33%) in high TB regions vs 2.05% (0.90%, 3.56%) in low TB regions. While death due to TB was occasionally reported (P  =0.82), successful anti-tubercular treatment was common (13.95%). Conclusion TB is common in IIM, particularly in endemic regions though current data is largely heterogeneous. Extra-pulmonary forms and atypical sites including the muscle are frequent. Limited data suggests fair outcomes, although larger prospective studies may offer better understanding. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective To evaluate the long-term effects of pulse i.v. methylprednisolone (IVMP) or IVIG administered during the first year of diagnosis in DM and PM patients. Methods This is a retrospective single-centre cohort study of patients with PM/DM followed for up to 4 years from 2001 to 2017. We used Cox regression models to estimate hazard ratios (HRs) and assess the effects of early pulse IVMP or IVIG on three outcomes: complete clinical response, CS discontinuation, and survival. Analysis was adjusted for clinical, laboratory and treatment covariates. Results A total of 204 patients were included and categorized into four initial treatment groups: pulse IVMP (n  = 46), pulse IVMP + IVIG (n  = 55), IVIG (n  = 10), and without IVMP or IVIG (n  = 93). The groups of early pulse IVMP and pulse IVMP + IVIG had a higher HR for complete clinical response in the multivariate models (HR = 1.56, 95% CI: 1.05, 2.33, P   =  0.029; and HR = 1.58, 95% CI: 1.02, 2.45, P   =  0.041, respectively). Only the group of pulse IVMP + IVIG had a significant association with CS discontinuation in the multivariate analysis (HR = 1.65, 95% CI: 1.02, 2.68, P   =  0.043). Early pulse IVMP or IVIG had no impact on mortality. Conclusion Despite having a more severe disease profile, patients with PM/DM submitted to pulse IVMP or pulse IVMP + IVIG during the first year of diagnosis had a higher HR for complete clinical response, whereas the combination of pulse IVMP + IVIG had an association with CS discontinuation. Prospective long-term studies are warranted to confirm these benefits of early pulse IVMP and IVIG on patients with PM/DM. [ABSTRACT FROM AUTHOR]

Objectives We aimed to identify disease-specific surface proteins on extracellular vesicles (EVs) as novel serum biomarkers of PM/DM. Methods We performed liquid chromatography–tandem mass spectrometry (LC/MS) on purified EVs from sera of 10 PM/DM patients, 23 patients with other autoimmune diseases and 10 healthy controls (HCs). We identified membrane proteins preferentially present in EVs of PM/DM patients by bioinformatics and biostatistical analyses. We developed an EV sandwich ELISA for directly detecting serum EVs expressing disease-specific membrane proteins and evaluated their clinical utility using sera from 54 PM/DM, 24 RA, 20 SLE, 13 SSc and 25 Duchenne and Becker types of muscular dystrophy (DMD/BMD) patients and 36 HCs. Results LC/MS analysis identified 1220 proteins in serum EVs. Of these, plexin D1 was enriched in those from PM/DM patients relative to HCs or patients without PM/DM. Using a specific EV sandwich ELISA, we found that levels of plexin D1+ EVs in serum were significantly greater in PM/DM patients than in HCs or RA, SLE or DMD/BMD patients. Serum levels of plexin D1+ EVs were greater in those PM/DM patients with muscle pain or weakness. Serum levels of plexin D1+ EVs were significantly correlated with levels of aldolase (r s = 0.481), white blood cells (r s = 0.381), neutrophils (r s = 0.450) and platelets (r s = 0.408) in PM/DM patients. Finally, serum levels of plexin D1+ EVs decreased significantly in patients with PM/DM in clinical remission after treatment. Conclusion We identified levels of circulating plexin D1+ EVs as a novel serum biomarker for PM/DM. [ABSTRACT FROM AUTHOR]

Objective We recently recorded a high prevalence of inclusion body myositis (IBM) in patients with Sjögren's syndrome (SS). Whether myositis patients with SS differ from myositis patients without SS in terms of the characteristics of the myositis is currently unknown. Anti-cytosolic 5′-nucleotidase 1 A (cN1A) has recently been proposed as a biomarker for IBM but is also frequent in SS. Whether anti-cN1A is independently associated with IBM is still an open question. We aimed to assess the significance of SS and anti-cN1A in myositis patients. Methods Cumulative data on all myositis patients (EULAR/ACR 2017 criteria) screened for SS (ACR/EULAR 2016 criteria) in a single centre were analysed. Ninety-nine patients were included, covering the whole spectrum of EULAR/ACR 2017 myositis subgroups and with a median follow-up of 6 years (range 1.0–37.5). The 34 myositis patients with SS (myositis/SS+) were compared with the 65 myositis patients without SS (myositis/SS-). Results. IBM was present in 24% of the myositis/SS+ patients vs 6% of the myositis/SS- group (P = 0.020). None of the IBM patients responded to treatment, whether they had SS or not. Anti-cN1A was more frequent in myositis/SS+ patients (38% vs 6%, P = 0.0005), independently of the higher prevalence of IBM in this group (multivariate P value: 0.02). Anti-cN1A antibody specificity for IBM was 0.96 (95% CI: 0.87, 0.99) in the myositis/SS- group but dropped to 0.70 (95% CI: 0.48, 0.85) in the myositis/SS+ group. Interpretation In myositis patients, SS is associated with IBM and with anti-cN1A antibodies, independently of the IBM diagnosis. As a consequence, anti-cN1A has limited specificity for IBM in myositis patients with SS. [ABSTRACT FROM AUTHOR]

Objective Myocardial involvement is frequently observed in PM and DM but typically remains subclinical. This study aimed to investigate characteristics of myocardial involvement and compare differences between patients with PM and DM by cardiac MR (CMR) imaging. Methods From March 2017 to December 2019, a total of 17 PM and 27 DM patients were enrolled in this retrospective study. In all patients, clinical assessment and CMR examination were performed. CMR parameters, including left ventricular (LV) morphologic and functional parameters, and CMR tissue characterization imaging parameters, such as native T1, T2, extracellular volume (ECV) and late gadolinium enhancement, were analysed. Results In patients in both PM and DM groups, elevated global native T1 and ECV values were observed. Global ECV values were higher in the PM group when compared with the DM group (33.24 ± 2.97% vs 30.36 ± 4.20%; P   =  0.039). Furthermore, patients in the PM and DM groups showed a different positive segment distribution of late gadolinium enhancement, native T1 and ECV, whereas the number of positive segments in PM patients was greater compared with that in DM patients. No significant differences in LV morphological and functional parameters were observed between patients in PM and DM groups, and most were in normal range. Conclusion CMR tissue characterization imaging could detect early myocardial involvement in PM and DM patients without overt LV dysfunction. Furthermore, characteristics of myocardial involvement were different between PM and DM patients with more serious myocardial involvement seen in PM patients. [ABSTRACT FROM AUTHOR]

Objective To assess the association of severe pulmonary arterial hypertension (PAH) with particulate matter <2.5 μm (p.m.2.5) and clinical data in patients with systemic autoimmune rheumatic diseases (SARDs). Methods We used the 2003–2017 nationwide data in Taiwan to identify patients with SARDs, including systemic lupus erythematosus, rheumatoid arthritis, systemic sclerosis, dermatomyositis/polymyositis and primary Sjögren's syndrome. We identified 479 cases with severe PAH and selected controls matched (1:4) for age, sex, and index year. We used conditional logistic regression analysis to determine factors associated with risks for severe PAH shown as odds ratios (ORs) with 95% confidence intervals (CIs). Results We found that severe PAH was highly associated with interstitial lung disease (OR, 8.57; 95% CI: 5.52, 13.32), congestive heart failure (OR, 7.62; 95% CI: 5.02, 11.55), valvular heart disease (OR, 3.34; 95% CI: 2.03, 5.50) and slightly associated with thyroid diseases (OR, 1.88; 95% CI: 1.18, 3.00), but not the level of exposure to p.m.2.5. Increased risk for PAH was found in patients receiving corticosteroid (prednisolone equivalent dosage, mg/day, OR, 1.03; 95% CI: 1.01, 1.05), biologics (OR, 2.18; 95% CI: 1.15, 4.12) as well as immunosuppressants, including ciclosporin (OR, 2.17; 95% CI: 1.31, 3.59), azathioprine (OR, 1.96; 95% CI: 1.48, 2.61), cyclophosphamide (OR, 2.01; 95% CI: 1.30, 3.11) and mycophenolate mofetil/mycophenolic acid (OR, 2.42; 95% CI: 1.37, 4.27), and those with the highest level of insured amount (reference, lowest level; OR, 0.53; 95% CI: 0.34, 0.83). Conclusion The population-based study identified risks for severe PAH in patients with SARDs, and these findings provide evidence for PAH risk stratification in patients with SARDs. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Objective DM and PM are associated with substantial morbidity and mortality. We aimed to examine recent trends. Methods Using The Health Improvement Network, we identified patients with incident DM/PM (defined by ≥1 Read diagnosis code) aged 18–89 years with ≥1 year of continuous enrolment prior to the cohort entry date and up to 10 comparators matched on age, sex and entry year. The cohort was divided in two based on the year of DM/PM diagnosis: the early cohort (1999–2006) and late cohort (2007–2014). We calculated multivariable hazard ratios (HR) for death using a Cox-proportional hazards model and multivariable rate differences (RD) using an additive hazard model. Results We identified 410 DM cases (mean age: 58 years, 66% female) and 407 PM cases (mean age: 59 years, 61% female). Both DM cohorts had excess mortality compared with the comparison cohorts (71.5 vs 12.9 deaths/1000 person-years [PY] in the early cohort and 49.1 vs 10.4 deaths/1000 PY in the late cohort). The multivariable HRs were 7.51 (95% CI: 4.20, 13.42) in the early cohort and 5.42 (95% CI: 3.11, 9.45) in the late cohort (P -value for interaction = 0.59), and multivariable RDs were 56.2 (95% CI: 31.8, 81.2) in the early cohort and 36.3 (95% CI: 19.6, 53.0) in the late cohort (P -value for interaction = 0.15). A similar trend existed in PM. Conclusion The premature mortality gap in DM/PM has not considerably improved in recent years, highlighting an unmet need for therapeutic improvement. [ABSTRACT FROM AUTHOR]

It is 120 years since 'angiomyositis' was included alongside 'polymyositis' and 'dermatomyositis' in an attempt to propose a taxonomy that reflected the major clinical characteristics of idiopathic inflammatory myopathy (IIM). Endothelial injury, perivascular inflammation and capillary loss are important histological findings in affected tissues in IIM. Overt vascular clinical features including RP and abnormal nailfold capillaroscopy (NC) are also common in IIM. Despite the presence of endothelial injury, perivascular inflammation and capillary loss in affected tissues in IIM, and the presence of clinical features such as RP and NC abnormalities, the pathogenic and therapeutic implications of vasculopathy in IIM have been somewhat overlooked. RP and NC abnormalities are not always present, providing a valuable opportunity to explore aetiopathogenic factors driving vasculopathy within autoimmune rheumatic disease. The present review examines the aetiopathogenic, prognostic and therapeutic significance of vasculopathy in IIM. We describe the prevalence and clinical relevance of vasculopathy in IIM, and consider how vasculopathy may be better utilized to support improved IIM diagnosis and disease classification. Areas of unmet research need are highlighted where relevant. [ABSTRACT FROM AUTHOR]

Objectives Few studies have investigated the prognostic factors for idiopathic inflammatory myopathy-associated interstitial lung disease (IIM-ILD) across different clinical/serological phenotypes. Methods We conducted a retrospective analysis of patients diagnosed with IIM between January 2012 and December 2017. Results Of the 760 IIM cases registered, 679 adult cases were included in this study. ILD was present in 508 cases, and the presence of ILD in the clinically amyopathic DM, DM and PM groups was 92.7, 73.6 and 55.1%, respectively (P  < 0.01). The prevalence of ILD in the anti-synthetase antibody (ASA)+-IIM group was higher than that in ASA–-IIM group (95.2 vs 72.4%, P  < 0.01); no such difference was found between the anti-histidyl-tRNA synthetase (Jo-1)+-IIM and Jo-1–ASA+-IIM groups (93.0 vs 98.5%, P  > 0.05). The prevalence of ILD in the melanoma differentiation-associated protein-5 (MDA-5)+-IIM group was higher than that in MDA-5–-IIM group (97.8 vs 72.1%, P  < 0.01). Among adults with IIM, men with concurrent ILD, who were older than 50 years, were most likely to die. No significant difference was found in the all-cause mortality rates between DM-ILD and clinically amyopathic DM-ILD groups (33.3 vs 23%, P  > 0.05), although both were higher than that in PM group (13.2%, P  = 0.01 and P  < 0.05, respectively). No difference was found in the all-cause mortality rates between MDA5–ASA–-IM-ILD and MDA5–ASA+-IM-ILD groups (17.2 vs 12.8%, P  > 0.05), and both were lower than that in MDA5+ASA–-IM-ILD group (33.7%, P  < 0.05). Conclusion The prevalence of ILD in IIM and the prognosis of IIM-ILD patients may vary depending on the statuses of the ASA and MDA-5 antibodies. [ABSTRACT FROM AUTHOR]

Objective Dysphagia is a life-threating manifestation of idiopathic inflammatory myopathies (IIM). However, we lack a univocal protocol for its treatment. The aim of this retrospective analysis was to evaluate the effectiveness of a step-up strategy by adding a 1-day pulse of IVIGs to immunosuppressants in IIM patients with refractory dysphagia diagnosed by Eating Assessment Tool (EAT)-10 and fibreoptic endoscopic evaluation of swallowing (FEES). Methods Dysphagia was defined as a pharyngo-oesophageal disturbance associated with EAT-10 score ≥3 and at least one FEES abnormality among propulsion failure, solid or liquid stasis. Eighteen out of 154 IIM patients had FEES-confirmed dysphagia and underwent 1 day IVIG 2 g/kg repeated 1 month apart for 3 months, because of dysphagia refractory to high-dose glucocorticoids with methotrexate and/or azathioprine. Clinical characteristics along with myositis-specific antibodies and muscle histopathological findings were studied in FEES-dysphagia IIM and IIM control patients. Results After three monthly doses of IVIG, EAT-10 score dropped with complete recover of defective propulsion and progressive decrease in percentage of both solid and liquid stasis. At 52-weeks' follow-up, reached in 12 patients, all these parameters were stable or further improved. An improvement in manual muscle strength test and a steroid-sparing effect of IVIG were also observed. Anti-PM/Scl 75/100 antibodies were much more frequent in the FEES-dysphagia group, while anti-Jo1 antibody was rarely detected. Conclusion Our treatment schedule with 2 g/kg IVIG was effective for IIM-associated refractory dysphagia assessed by the combination of EAT-10 and FEES. These findings need to be prospectively tested in a larger cohort of IIM patients. [ABSTRACT FROM AUTHOR]

The article describes the case of a 10-year-old boy with fever and stormatitis and developed gradual muscle weakness and myalgia, followed by the complaint of dark spots in front of the eyes. Topics discussed include findings on physical examination and laboratory tests, his diagnosis with enterovirus infection with polymyositis (PM) and necrotizing retinovasculitis, and key points requiring differential diagnosis.

Objectives To refine the prevalence, characteristics and response to treatment of myositis in primary SS (pSS). Methods The multicentre prospective Assessment of Systemic Signs and Evolution in Sjögren's Syndrome (ASSESS) cohort of 395 pSS patients with ≥60 months' follow-up was screened by the 2017 EULAR/ACR criteria for myositis. Extra-muscular complications, disease activity and patient-reported scores were analysed. Results Before enrolment and during the 5-year follow-up, myositis was suspected in 38 pSS patients and confirmed in 4 [1.0% (95% CI: 0.40, 2.6)]. Patients with suspected but not confirmed myositis had higher patient-reported scores and more frequent articular and peripheral nervous involvement than others. By contrast, disease duration in patients with confirmed myositis was 3-fold longer than without myositis. Two of the four myositis patients fulfilled criteria for sporadic IBM. Despite receiving three or more lines of treatment, they showed no muscle improvement, which further supported the sporadic IBM diagnosis. The two other patients did not feature characteristics of a myositis subtype, which suggested 'pure' pSS myositis. Steroids plus MTX was then efficient in achieving remission. Conclusions Myositis, frequently suspected, occurs in 1% of pSS patients. Especially when there is resistance to treatment, sporadic IBM should be considered and might be regarded as a late complication of this disease. [ABSTRACT FROM AUTHOR]

Objectives Galectin-3 is involved in various biological activities, including immune activations and fibrosis. Idiopathic inflammatory myopathies (IIMs) are autoimmune diseases of unknown aetiology, often complicated by interstitial lung disease (ILD). The aim of this study was to evaluate the expression of galectin-3 in sera and tissues of patients with IIM and assess the associations of galectin-3 with patient characteristics and disease activity. Results Serum galectin-3 levels were significantly higher in IIM patients than in healthy controls. The serum galectin-3 levels positively correlated with serum levels of inflammatory markers and proinflammatory cytokines/chemokines and the Myositis Intention-to-Treat Activity Index. Stratification analysis revealed that patients with IIM-associated ILD (IIM-ILD) had significantly higher levels of serum galectin-3 than those without IIM-ILD. In addition, patients with acute/subacute interstitial pneumonia had significantly higher levels of serum galectin-3 than those with chronic interstitial pneumonia. Furthermore, serum galectin-3 levels in IIM-ILD patients correlated with the radiological assessments of parenchymal lung involvement and treatment response. Immunohistochemical analysis revealed that galectin-3 was expressed in inflammatory cells of myositis and dermatitis sections, whereas in ILD sections, galectin-3 was expressed in interstitial fibrosis and inflammatory cells. Conclusion Galectin-3 may be involved in the pathogenesis of inflammatory and fibrotic conditions in IIM and can serve as a potential biomarker of disease activity, especially in patients with IIM-ILD. [ABSTRACT FROM AUTHOR]

Objectives To describe the prevalence and clinical associations of autoantibodies to a novel autoantigen, eukaryotic initiation factor 3 (eIF3), detected in idiopathic inflammatory myositis. Methods Sera or plasma from 678 PM patients were analysed for autoantigen specificity by radio-labelled protein immunoprecipitation (IPP). Samples immunoprecipitating the same novel autoantigens were further analysed by indirect immunofluorescence and IPP using pre-depleted cell extracts. The autoantigen was identified through a combination of IPP and MALDI-TOF mass spectrometry, and confirmed using commercial antibodies and IPP-western blots. Additional samples from patients with DM (668), DM-overlap (80), PM-overlap (191), systemic sclerosis (150), systemic lupus erythematosus (200), Sjogren's syndrome (40), rheumatoid arthritis (50) and healthy controls (150) were serotyped by IPP as disease or healthy controls. Results IPP revealed a novel pattern in three PM patients (0.44%) that was not found in disease-specific or healthy control sera. Indirect immunofluorescence demonstrated a fine cytoplasmic speckled pattern for all positive patients. Mass spectrometry analysis of the protein complex identified the target autoantigen as eIF3, a cytoplasmic complex with a role in the initiation of translation. Findings were confirmed by IPP-Western blotting. The three anti-eIF3-positive patients had no history of malignancy or interstitial lung disease, and had a favourable response to treatment. Conclusion We report a novel autoantibody in 0.44% of PM patients directed against a cytoplasmic complex of proteins identified as eIF3. Although our findings need further confirmation, anti-eIF3 appears to correlate with a good prognosis and a favourable response to treatment. [ABSTRACT FROM AUTHOR]

Objective Interstitial pneumonia is common and has high short-term mortality in patients with PM and DM despite glucocorticoid (GC) treatment. Retrospective studies suggested that the early use of immunosuppressive drugs with GCs might improve its short-term mortality. Methods A multicentre, single-arm, 52-week-long clinical trial was performed to test whether the initial combination treatment with tacrolimus (0.075 mg/kg/day, adjusted for the target whole-blood trough levels between 5 and 10 ng/ml) and GCs (0.6–1.0 mg/kg/day of prednisolone followed by a slow taper) improves short-term mortality of PM/DM-interstitial pneumonia patients. The primary outcome was overall survival. We originally intended to compare, by using propensity-score matching, the outcome data of clinical trial patients with that of historical control patients who were initially treated with GCs alone. Results The 52-week survival rate with the combination treatment (N = 26) was 88.0% (95% CI, 67.3, 96.0). Safety profiles of the combination treatment were consistent with those known for tacrolimus and high-dose GCs individually. Serious adverse events occurred in 11 patients (44.0%), which included four opportunistic infections. Only 16 patients, including only 1 deceased patient, were registered as historical controls, which precluded meaningful comparative analysis against the clinical trial patients. Conclusion Our study provided findings which suggest that initial treatment with tacrolimus and GCs may improve short-term mortality of PM/DM-interstitial pneumonia patients with manageable safety profiles. This was the first prospective clinical investigation conducted according to the Good Clinical Practice Guideline of the International Conference on Harmonization for the treatment of this potentially life-threatening disease. Trial registration ClinicalTrials.gov, http://clinicaltrials.gov , NCT00504348. [ABSTRACT FROM AUTHOR]

Objective The aim of this study was to clarify predictive factors for sustained remission in adult patients with PM/DM, particularly focusing on stratification by myositis-specific autoantibodies (MSAs). Methods A total of 162 adult patients with PM/DM who were followed up for >1 year after diagnosis were retrospectively enrolled. MSAs were evaluated comprehensively in 102 patients whose sera were available. Sustained remission was defined as no evidence of disease activity (active skin rash, active myositis or active interstitial lung disease) for longer than a 6-month continuous period while undergoing myositis therapy or no medication. Clinical data were reviewed in patients' medical charts Results The sustained remission rate for all patients was 58% during the median follow-up period at 4 years. With regard to MSAs, the achievement rate of sustained remission among MSA-negative patients was significantly higher than that for patients with anti-aminoacyl-tRNA synthetase (P = 0.004), anti-melanoma differentiation-associated gene 5 (P = 0.037) or anti-transcriptional intermediary factor 1-γ (P = 0.013) antibodies. MSA-negative status (odds ratio 5.84, P = 0.009) and absence of severe muscle weakness requiring assistance at diagnosis (odds ratio 43.6, P < 0.001) were independent factors associated with sustained remission in multivariate analysis. Cumulative remission rates were significantly higher (P < 0.001) in patients with both the MSA-negative status and absence of severe muscle weakness at diagnosis than the others. Conclusion MSA-negative status and the absence of severe muscle weakness requiring assistance at diagnosis are independent predictive factors for sustained remission in adult PM/DM patients. [ABSTRACT FROM AUTHOR]

Objectives To elucidate the serum cytokine profile and address the pathomechanism of interstitial lung disease (ILD) complicated with PM/DM. Methods Forty patients with PM/DM-ILD were enrolled, and principal components analysis and cluster analysis were performed to classify patients into subgroups. Additionally, we compared cytokine profiles between the survivors and dead patients and between anti-melanoma differentiation-associated gene 5 antibody- and anti-aminoacyl tRNA synthetase antibody-positive ILD patients. We also examined the association of various cytokines with disease activity indicators and prognosis of ILD. Results The principal components analysis data allowed classification of the cytokine profile into three groups: group 1, neutrophilic and M1-macrophage-driven cytokines; group 2, type 1 Th cell-driven and M2-macrophage-induced cytokines; and group 3, M2-macrophage-driven cytokines. Cluster analysis showed the presence of PM/DM-ILD patient groups with high or low levels of total cytokines. Ninety percent of patients who died of ILD were included in clusters with high cytokine levels. Serum cytokine levels of all groups were significantly higher in the anti-melanoma differentiation-associated gene 5 antibody-positive patients than in the anti-aminoacyl tRNA synthetase antibody-positive patients. Groups 1 and 2 significantly correlated with known factors for poor prognosis, such as serum ferritin levels and alveolar-arterial oxygen difference. Serum cytokine levels of patients in group 1 were significantly higher initially and at 2 and 4 weeks in those who died. Conclusion These findings suggested that the activation of monocytes, macrophages and type 1 Th cells, and neutrophils play roles in the pathomechanism of PM/DM-ILD, and group 1 cytokines could be useful biomarkers for predicting prognosis of PM/DM-ILD. [ABSTRACT FROM AUTHOR]

Objective The inflammatory idiopathic myopathies (IIM) are a group of rare autoimmune diseases defined by muscle weakness and characterized by pro-inflammatory infiltrates in muscle. Little is known about the immunological profile in peripheral blood of these patients and how this relates to IIM subtypes. This study aimed to stratify adult and juvenile-onset IIM patients according to immune cell profile. Methods Peripheral blood mononuclear cells from 44 patients with adult myositis (AM), 15 adolescent-onset juvenile dermatomyositis (a-JDM), and 40 age-matched healthy controls were analysed by flow cytometry to quantify 33 immune cell subsets. Adult myositis patients were grouped according to myositis subtype; DM and polymyositis; and also autoantibody specificity. Disease activity was determined by the myositis disease activity assessment tool and clinicians' decision on treatment. Results Unique immune signatures were identified for DM, polymyositis and a-JDM compared with healthy controls. DM patients had a T-cell signature comprising increased CD4+ and TH17 cell frequencies and increased immune cell expression of IL-6. Polymyositis patients had a B-cell signature with reduced memory B cells. A-JDM had decreased naïve B cells and increased CD4+T cells. All patient groups had decreased CD8+central memory T-cell frequencies. The distinct immune signatures were also seen when adult myositis patients were stratified according to auto-antibody expression; patients with anti-synthetase-antibodies had reduced memory B cells and patients with autoimmune rheumatic disease overlap had an elevated Th17 profile. Conclusion Unique immune signatures were associated with adult vs juvenile disease. The Th17 signature in DM patients supports the potential use of IL-17 inhibitors in treatment of IIMs. [ABSTRACT FROM AUTHOR]

Objectives The hallmark histopathology of PM is the presence of CD8+ T cells in the non-necrotic muscle cells. The aim of this study was to clarify the pathological significance of CD8+ T cells in muscle cells. Methods C2C12 cells were transduced retrovirally with the genes encoding MHC class I (H2Kb) and SIINFEKL peptide derived from ovalbumin (OVA), and then differentiated to myotubes (H2KbOVA-myotubes). H2KbOVA-myotubes were co-cultured with OT-I CD8+ T cells derived from OVA-specific class I restricted T cell receptor transgenic mice as an in vitro model of PM to examine whether the CD8+ T cells invade into the myotubes and if the myotubes with the invasion are more prone to die than those without. Muscle biopsy samples from patients with PM were examined for the presence of CD8+ T cells in muscle cells. The clinical profiles were compared between the patients with and without CD8+ T cells in muscle cells. Results Analysis of the in vitro model of PM with confocal microscopy demonstrated the invasion of OT-I CD8+ T cells into H2KbOVA-myotubes. Transmission electron microscopic analysis revealed an electron-lucent area between the invaded CD8+ T cell and the cytoplasm of H2KbOVA-myotubes. The myotubes invaded with OT-I CD8+ T cells died earlier than the uninvaded myotubes. The level of serum creatinine kinase was higher in patients with CD8+ T cells in muscle cells than those without these cells. Conclusion CD8+ T cells invade into muscle cells and contribute to muscle injury in PM. Our in vitro model of PM is useful to examine the mechanisms underlying muscle injury induced by CD8+ T cells. [ABSTRACT FROM AUTHOR]

Objective To clarify the incidence, risk factors, and impact of malignancy in patients with PM/DM-associated interstitial lung disease (ILD). Methods This study used data from 497 patients with PM/DM-associated ILD enrolled in a multicentre, retrospective and prospective cohort of incident cases. Cancer-associated myositis (CAM) was defined as malignancy diagnosed within 3 years before or after PM/DM diagnosis. Demographic and clinical information was recorded at the time of diagnosis, and data about the occurrence of mortality and malignancy was collected. Results CAM was identified in 32 patients with PM/DM-associated ILD (6.4%). Patients with CAM were older (64 vs 55 years, P < 0.001), presented with arthritis less frequently (24% vs 49%, P = 0.01), and showed a lower level of serum Krebs von den Lungen-6 (687 vs 820 IU/l, P = 0.03) than those without CAM. The distribution of myositis-specific autoantibodies, including anti-melanoma differentiation–associated gene 5, anti-aminoacyl tRNA synthetase, and anti-transcriptional intermediary factor 1-γ antibodies, did not differ between the groups. Survival analysis demonstrated that CAM patients had a poorer survival than non-CAM patients (P = 0.006), primarily due to excess deaths by concomitant malignancy, while mortality due to ILD-related respiratory failure was similar between the groups (P = 0.51). Conclusion Concomitant malignancy can occur in patients with PM/DM-associated ILD, and has significant impact on mortality. Older age, lack of arthritis, and a lower level of serum Krebs von den Lungen-6 at diagnosis are predictors of concomitant malignancy. [ABSTRACT FROM AUTHOR]

The article discusses a study which identified a patient with juvenile polymositis (JPM) with recurrent macrophage activation syndrome (MAS) who carried a homozygous missense UNC13D mutation. Topics discussed include findings on physical examination of the patient, assessment of the probability of juvenile idiopathic inflammatory myopathies (IIM) by EULAR/ACR classification criteria, and the need for early genetic analysis in MAS patients.

Objective To evaluate the risk of incident coronary heart disease (CHD) among patients with DM and PM in a general population context. Methods We conducted a retrospective cohort study using the Taiwan National Health Insurance Research Database containing records covering the years from 2000 to 2010. DM and PM were confined for the purposes of this study to those aged ⩾18 years who were eligible for the Taiwan catastrophic illness certificate. The diagnoses, CHD outcomes and cardiovascular risk factors were identified from electronic claims data. We conducted two cohort analyses: CHD and DM, and CHD and PM, excluding for each analysis individuals with CHD already identified at baseline. Data for the comparison group was obtained from the Longitudinal Health Insurance database, comprising 1 million persons randomly sampled from the total beneficiaries during 2000. We estimated hazard ratios comparing myositis with comparison cohorts, adjusting for potential cardiovascular risk factors. Results A total of 1145 patients with idiopathic myositis were identified, along with 732 723 control patients aged ⩾18 years. The incidence rates of CHD were 15.1 in DM and 30.1 in PM per 1000 person-years, vs 8.4 and 10.5 per 1000 person-years in the comparison cohort. The adjusted hazard ratios for CHD in patients with idiopathic myositis were 2.21 (95% CI 1.64, 2.99) for DM and 3.73 (95% CI 2.83, 4.90) for PM. Conclusion Results of this general population-based cohort study suggest that DM and PM are associated with an increased risk of CHD. [ABSTRACT FROM AUTHOR]

Objectives The objective of this study was to compare the results obtained from different assays for the detection of anti-Mi-2 antibodies, which are important markers in the diagnosis of DM. Methods The study included 82 patients (68 females/14 males), most of whom had DM (n = 57), followed by PM (n = 16) and juvenile DM (n = 9). All samples were tested using a novel particle-based multi-analyte technology (PMAT) (Inova Diagnostics, research use only) in parallel with a line immunoassay (LIA: Euroimmun). To assess clinical specificity for the PMAT assay, a total of 775 disease and healthy controls were tested. Results 29 samples were positive by at least one test for anti-Mi-2 antibodies. Of those, 24 were Mi-2β LIA+, five were Mi-2α LIA+ and 23 Mi-2 PMAT+. The comparison shows varying agreement between the different methods (kappa 0.27–0.77). When LIA results were used as reference for receiver operating characteristics analysis, high area under the curve values were found for both PMAT vs LIA Mi-2α and LIA Mi-2β. When analysing the results in the context of the myositis phenotype, PMAT associated closest with the DM phenotype. In the control group, 3/775 controls (all low levels) were anti-Mi-2+ resulting in a sensitivity and specificity of 28.1% and 99.6%, respectively. Conclusion Overall, good agreement was found between LIA and PMAT for anti-Mi-2 antibodies, which is important for the standardization of autoantibodies. Anti-Mi-2β antibodies measured by PMAT tend be more highly associated with the clinical phenotype of DM. [ABSTRACT FROM AUTHOR]

Objective We aimed to clarify the clinical significance of serum levels of MMPs in interstitial lung disease (ILD) complicated with PM/DM (PM/DM-ILD). Methods We retrospectively analysed serum levels of seven subsets of MMPs in 52 PM/DM-ILD patients diagnosed at Kyoto University Hospital or Tenri Hospital from January 2005 to December 2014. The patients were sub-grouped based on the presence of anti-amimoacyl-tRNA synthetase antibody (anti-ARS antibody), anti-melanoma differentiation-associated protein 5 antibody (anti-MDA5 antibody) or lack of the antibodies (ARS-ILD, MDA5-ILD and other-ILD groups, respectively) and independently analysed. Eighteen PM/DM patients without ILD and 55 healthy control were also analysed. Associations between serum levels of MMPs and clinical findings including mortality were analysed. Results Among the MMPs analysed, MMP-7 serum levels in the ARS-ILD group were significantly higher compared with those in any of the other groups of PM/DM patients or in healthy controls. On the other hand, in the MDA5-ILD group, serum MMP-7 levels >5.08 ng/ml were associated with worse overall survival both in univariate (P = 0.017; odds ratio 18.0; 95% CI 1.69, 192.00) and multivariate (P = 0.027; odds ratio 14.60; 95% CI 1.11, 192.00) analyses. Immunohistochemical analysis suggested that MMP-7 was expressed in type II alveolar epithelial cells adjacent to the fibrotic lesions. Conclusion Serum MMP-7 levels were higher in anti-ARS antibody-positive PM/DM-ILD patients, while higher serum MMP-7 levels among anti-MDA5 antibody-positive PM/DM-ILD patients were associated with a worse prognosis. Fibrotic processes may be associated with the elevation of serum MMP-7 levels. [ABSTRACT FROM AUTHOR]

Objectives DM and PM are characterized by myofibre damage with inflammatory cell infiltration due to the strong expressions of MHC class I HLA-A and monocyte chemoattractant protein-1 (MCP-1). Dysferlin (DYSF) is a transmembrane glycoprotein that anchors in the sarcolemma of myofibres. DYSF mutation is closely associated with inherited myopathies. This study aimed to determine the role of DYSF in the development of DM/PM. Methods Mass spectrometry was performed in muscle tissues from DM/PM patients and controls. The DYSF levels in muscle tissue, peripheral blood cells and serum were detected by Western blotting, IF, flow cytometry or ELISA. Double IF and co-immunoprecipitation were used to investigate the relationship between DYSF and HLA-A. Results Mass spectrometry and bioinformatics analysis findings suggested the dysregulated proteins in DM/PM patients participated in common biological processes and pathways, such as the generation of precursor metabolites and energy. DYSF was upregulated in the muscle tissue and serum of DM/PM patients. DYSF was mainly expressed in myofibres and co-localized with HLA-A and MCP-1. DYSF and HLA-A expressions were elevated in myocytes and endothelial cells after being stimulated by patient serum and IFN-β. However, no direct interactions were found between DYSF and HLA-A by co-immunoprecipitation. Conclusion Our study revealed the dysregulated proteins involved in common and specific biological processes in DM/PM patient samples. DYSF is upregulated and exhibits a potential role along with that of HLA-A and MCP-1 in inflammatory cell infiltration and muscle damage during the development of DM/PM. [ABSTRACT FROM AUTHOR]

Objective To devise a simple PET-CT score for measurement of muscle disease activity in patients with inflammatory myopathies (IMs) and to assess its validity. Methods A total of 44 PET-CT examinations in 34 IM patients (performed during cancer screening) and 20 PET-CT examinations in matched controls (investigated for pulmonary nodules with a conclusion of benignity) were analysed. Maximal standardized uptake values (SUVmax) were recorded bilaterally in eight proximal muscles. The muscle SUVmax (mSUVmax) was defined as the average of the 16 muscle SUVmax values, normalized on the liver mean SUV. Reliability, validity and responsiveness were evaluated. Results The mSUVmax was increased in IM patients compared with controls. This index allowed the identification of patients with high vs low muscle disease activity using the myositis intention to treat activity index as the gold standard. In patients with subsequent examinations, our method showed good accuracy to detect changes in muscle disease activity [area under the curve 0.96 (95% CI 0.84, 1)]. Responsiveness was strong. Interrater reliability was excellent. Conclusion PET-CT, a non-invasive tool useful for cancer screening, is also valuable to measure muscle disease activity and its evolution in IM patients. [ABSTRACT FROM AUTHOR]

The article discusses research which investigated safety and effectiveness of rituximab in anti-synthetase antibody positive and negative patients with idiopathic inflammatory myopathy (IIM). Topics explored include the clinical characteristics and prevalence of IIM, the selection and evaluation of patients from the Swedish Rheumatology Quality Register, and brief details about the rituximab dosage administered and patient outcomes observed.

Objective To identify biomarkers for assessing myositis-associated interstitial lung disease (ILD). Methods We reviewed consecutive patients from our institution who had been newly diagnosed with PM, DM, or clinically amyopathic DM during the years 2002–2017. The patients were divided into two groups according to the presence of ILD, and the ILD group was further subdivided into three groups according to the clinical courses of induction failure, relapse and non-relapse. Baseline and time-course changes in the parameters were compared between groups. Results Among 110 patients enrolled, 75 (68%) had ILD. Baseline serum Krebs von den Lungen-6 (KL-6) was significantly higher in the ILD group than in the non-ILD group (1120 vs 236 U/ml; P < 0.001). In the ILD group consisting of the induction failure cases (n = 3), the relapse group (n = 24) and the non-relapse group (n = 48), baseline serum KL-6 was significantly different between the three groups [1971 vs 1870 vs 935 U/ml, respectively; P = 0.003 (relapse group vs non-relapse group)]. The time-course changes in serum KL-6 revealed that KL-6 significantly increased along with relapse, with the increase of 625 U/ml relevant to relapse. Conclusion Serum KL-6 is a useful biomarker for assessing the disease activity of myositis-associated ILD. [ABSTRACT FROM AUTHOR]

Objectives To assess the performance of the EULAR/ACR idiopathic inflammatory myopathies (IIMs) classification criteria in a cohort of incident IIM cases and examine how criteria-assigned IIM subtype correlates with expert opinion. Methods Adults with newly diagnosed IIM attending Salford Royal NHS Foundation Trust were identified over a 10 year period. A retrospective review of all putative cases was performed and those fulfilling a consensus expert opinion diagnosis of IIM were included. Clinical, serological and histological data were collected and each case was assigned a single IIM subtype. The EULAR/ACR classification criteria were then applied and sensitivity, specificity and positive and negative predictive values were calculated, presented with 95% CIs. Results A total of 1637 cases were screened, with 255 consensus expert opinion IIM cases ultimately identified. Applying the EULAR/ACR classification criteria, the sensitivity to diagnose an IIM was 99.6% (95% CI 97.2, 100) and 80.9% (95% CI 76.0, 85.8) for the criteria cut-points of probable and definite diagnoses, respectively. In 94/255 cases the IIM subtype differed between consensus expert opinion and classification criteria, most strikingly in the group subtyped as PM by the EULAR/ACR criteria, where there was discrepancy in the majority (i.e. in 87/161). Conclusion The EULAR/ACR criteria performed with high sensitivity in identifying IIM in this external cohort of incident IIM. However, substantial disagreements arose between consensus expert opinion and the criteria regarding IIM subtype assignments, resulting in a large proportion of criteria-assigned cases of PM having heterogeneous features. These results may have important implications for future use of these criteria in subsequent research. [ABSTRACT FROM AUTHOR]

Objective The aim of this study was to investigate the clinical and immunological significance of nailfold videocapillaroscopy (NVC) abnormalities in patients with idiopathic inflammatory myopathies (IIMs). Methods Seventy consecutive Japanese patients with untreated IIMs, enrolled between April 2014 and August 2017, were prospectively studied. Clinical features, NVC findings, autoantibody profile by immunoprecipitation and ELISA, and histopathological findings of skin biopsies of DM rash were assessed at baseline and after 1-year of immunosuppressive therapy. Results NVC abnormalities were found in 55.7% (39/70) of IIM patients, with significantly higher prevalence in DM (65.4%) compared with PM (27.8%) (P = 0.01). In subsets of patients classified by autoantibody specificities, the prevalence of NVC abnormalities was significantly higher in patients with anti-MDA5 (87.5%) and anti-transcriptional intermediary factor 1γ (88.9%) vs anti-aminoacyl-tRNA synthetase (26.9%, P < 0.001). Perivascular lymphocytic infiltration in the upper dermis of skin rash biopsy of DM was more severe in patients with NVC abnormalities (P < 0.05). Unexpectedly, NVC abnormalities disappeared in 75% of IIM patients after 1-year of immunosuppressive therapy in contrast to stable NVC changes seen in scleroderma patients. Conclusion Nailfold microvascular abnormalities were common in DM patients, associated with anti-MDA5 and transcriptional intermediary factor 1γ antibodies, and perivascular inflammation in skin histology. NVC abnormalities in IIMs may become clinically useful markers for defining subsets of DM and understanding the pathogenesis of the clinical features seen in these patients. [ABSTRACT FROM AUTHOR]

Objectives To investigate the expression of IL-18 in symptomatic and asymptomatic muscle tissues of patients with PM and DM and the effects of conventional immunosuppressive treatment on such expression. Methods Two cohorts of patients were included in this study. The first cohort consisted of 10 new-onset myositis patients. IL-18 expression was compared between symptomatic and asymptomatic muscle biopsies that were taken prior to treatment. The second cohort consisted of another 10 patients with repeated muscle biopsies before and after 8 months with conventional immunosuppressive treatment. Using immunohistochemistry, IL-18 expression in muscle tissues was compared before and after treatment. Biopsies from seven healthy individuals were included as controls. Results IL-18 expression was predominantly localized to inflammatory cells and capillaries in patients and mostly to capillaries in healthy controls. Total IL-18 expression in muscle tissues from the new-onset patients, at both symptomatic and asymptomatic sites, was significantly higher compared with healthy controls (P = 0.007 and P = 0.002) with no statistical difference in appearances between symptomatic and asymptomatic sites. The number of IL-18 positive capillaries was not different among symptomatic, asymptomatic and healthy muscles. Total IL-18 expression appeared lower in biopsies from patients receiving and improving with immunosuppressive treatment, particularly the number of IL-18 positive inflammatory cells but not the number of IL-18 positive capillaries, which was consistent with significantly decreased expression of CD68+macrophages (P = 0.04). Conclusion IL-18 is highly expressed in muscle tissue in the context of inflammatory myopathies and based on its plausible effector functions could provide a novel therapeutic target in future. [ABSTRACT FROM AUTHOR]

In the article, the authors present a case of a 38-year-old female who was presented due to lactic acidosis, profound weakness and cardiorespiratory arrest to discuss the autosomal recessive disorder called late-onset multiple acyl-CoA dehydrogenase deficiency (MADD) presenting as polymyositis. Also cited are the possible causes of MADD and the responsiveness of MADD to riboflavin.

Objectives. Limitations in the methods available for identifying cardiac involvement and accurately quantifying disease activity in the idiopathic inflammatory myopathies (IIMs) may contribute to poor outcomes. We investigated the utility of different serum muscle damage markers [total creatine kinase (CK), cardiac troponin T (cTnT) and cardiac troponin I (cTnI)] to address these issues. Methods. We assessed disease activity and cardiac involvement using the International Myositis Assessment and Clinical Studies Group core set measures in 123 participants with confirmed adultonset IIM from the UK and Denmark. Total CK, cTnT and cTnI were measured. Associations were assessed using logistic regression and Spearman's ranked correlation. Results. Cardiac involvement (n = 18) was associated with higher cTnI levels, independent of overall disease activity [adjusted odds ratio 1.03 (95% CI 1.01, 1.05); P = 0.002]. An abnormal cTnI had the highest specificity and positive predictive value for cardiac involvement (95% and 62%, respectively). In those with a normal CK but elevated cTnT or cTnI, an association with increased disease activity scores was observed. Serum cTnT correlated with the physician (ρ = 0.39) and patient-assessed (ρ = 0.28) global visual analogue scales and HAQ (ρ = 0.41) more strongly than CK or cTnI levels. cTnT was the only marker to correlate with manual muscle testing scores (ρ =-0.24). Conclusion. Serum cTnI testing may have a role in screening for cardiac involvement in IIMs. Abnormal levels of serum cTnT and cTnI are associated with increased disease activity, including in those with a normal CK. [ABSTRACT FROM AUTHOR]