IL-15 is a biomarker involved in the development of rapidly progressive interstitial lung disease complicated with polymyositis/dermatomyositis

Baricitinib for anti-melanoma differentiation-associated protein 5 antibody-positive dermatomyositis-associated interstitial lung disease: a case series and literature review on Janus kinase inhibitors for the disease

Anti-melanoma differentiation-associated protein 5 antibody-positive dermatomyositis (anti-MDA5-DM) is frequently complicated by progressive interstitial lung disease (ILD), the prognosis of which is poor, and management is a major challenge. We treated three patients with anti-MDA5-DM-associated ILD (anti-MDA5-DM-ILD) using the Janus kinase (JAK) inhibitor, baricitinib, which improved lung opacities and saved two patients. We reviewed 6 patients with anti-MDA5-DM-ILD who had been treated with tofacitinib at our institution. Five of the patients survived, although discontinuation of tofacitinib due to complications was frequently observed. In addition, a literature search of patients with anti-MDA5-DM-ILD who were treated with JAK inhibitors yielded 21 articles involving 79 cases. All patients except one were treated with tofacitinib, and the survival rate was 75.9%. Although not statistically confirmed, the deceased patients tended to be older and had higher ferritin levels. A total of 92 complications were observed, 11 of which resulted in JAK inhibitor discontinuation. Cytomegalovirus reactivation comprised a substantial percentage of all complications and of those patients who required JAK inhibitor discontinuation. Five cases with fatal infective complications were also observed. While tofacitinib has been proposed to be a therapeutic option for anti-MDA5-DM-ILD, other JAK inhibitors, including baricitinib, are a treatment option. Further investigation is warranted to optimize treatment of anti-MDA5-DM-ILD.

Predicting the death of patients with anti-melanoma differentiation-associated protein-5-positive dermatomyositis-associated interstitial lung disease: A systematic review and meta-analysis

OBJECTIVES

To investigate the risk factors for death in anti-melanoma differentiation-associated protein-5-positive dermatomyositis-associated interstitial lung disease (ILD).

METHODS

Studies were identified by searching PubMed, Embase, Web of Science, and Cochrane Library. We calculated pooled risk ratios (RRs) or standardized mean differences (SMDs) and 95% confidence intervals (CIs) using random-effects models.

RESULTS

Twenty studies were selected. Factors that may increase death risk included older age (SMD: 0.62, 95% CI: 0.42-0.81), elevated Krebs von den Lungen-6 (SMD: 0.66, 95% CI: 0.47-0.86), lactate dehydrogenase (SMD: 0.87, 95% CI: 0.72-1.02), C-reactive protein (SMD: 0.62, 95% CI: 0.44-0.80), ferritin (SMD: 0.93, 95% CI: 0.71-1.15), creatine kinase (SMD: 0.28, 95% CI: 0.13-0.44), neutrophil (SMD: 0.34, 95% CI: 0.04-0.64), neutrophil-to-lymphocyte ratio (SMD: 0.52, 95% CI: 0.24-0.79), aspartate aminotransferase (SMD: 0.70, 95% CI: 0.45-0.94), shorter disease duration (SMD: -0.44, 95% CI: -0.67 to -0.21), rapidly progressive ILD (RR: 4.08, 95% CI: 3.01-5.54), fever (RR: 1.98, 95% CI: 1.46-2.69), dyspnoea (RR: 1.63, 95% CI: 1.32-2.02), and anti-Ro52 antibody positive (RR: 1.28, 95% CI: 1.11-1.49). Female (RR: 0.86, 95% CI: 0.78-0.94), increased albumin (SMD: -1.20, 95% CI: -1.76 to -0.64), lymphocyte (SMD: -0.49, 95% CI: -0.67 to -0.30), and arthralgia (RR: 0.53, 95% CI: 0.37-0.78) were protective factors.

CONCLUSION

Older age, shorter disease duration, rapidly progressive ILD, fever, dyspnoea, anti-Ro52 antibody positive, and some inflammatory markers were risk factors for death in patients with anti-melanoma differentiation-associated protein-5-positive dermatomyositis-associated ILD.

Effects of interleukin-15 on autophagy regulation in the skeletal muscle of mice

This study aimed to evaluate the role of skeletal muscle-derived interleukin (IL)-15 in the regulation of skeletal muscle autophagy using IL-15 knockout (KO) and transgenic (TG) mice. Male C57BL/6 wild-type (WT), IL-15 KO, and IL-15 TG mice were used in this study. Changes in muscle mass, forelimb grip strength, succinate dehydrogenase (SDH) activity, gene and protein expression levels of major regulators and indicators of autophagy, comprehensive gene expression, and DNA methylation in the gastrocnemius muscle were analyzed. Enrichment pathway analyses revealed that the pathology of IL-15 gene deficiency was related to the autophagosome pathway. Moreover, although IL-15 KO mice maintained gastrocnemius muscle mass, they exhibited a decrease in autophagy induction. IL-15 TG mice exhibited a decrease in gastrocnemius muscle mass and an increase in forelimb grip strength and SDH activity in skeletal muscle. In the gastrocnemius muscle, the ratio of phosphorylated adenosine monophosphate-activated protein kinase α (AMPKα) to total AMPKα and unc-51-like autophagy activating kinase 1 and Beclin1 protein expression were higher in the IL-15 TG group than in the WT group. IL-15 gene deficiency induces a decrease in autophagy induction. In contrast, IL-15 overexpression could improve muscle quality by activating autophagy induction while decreasing muscle mass. The regulation of IL-15 in autophagy in skeletal muscles may lead to the development of therapies for the autophagy-induced regulation of skeletal muscle mass and cellular quality control.NEW & NOTEWORTHY IL-15 gene deficiency can decrease autophagy induction. However, although IL-15 overexpression induced a decrease in muscle mass, it led to an improvement in muscle quality. Based on these results, understanding the role of IL-15 in regulating autophagy pathways within skeletal muscle may lead to the development of therapies for the autophagy-induced regulation of skeletal muscle mass and cellular quality control.

A nomogram based on clinical factors and CT radiomics for predicting anti-MDA5+ DM complicated by RP-ILD

OBJECTIVES

Anti-melanoma differentiation-associated gene 5 antibody-positive (anti-MDA5+) DM complicated by rapidly progressive interstitial lung disease (RP-ILD) has a high incidence and poor prognosis. The objective of this study was to establish a model for the prediction and early diagnosis of anti-MDA5+ DM-associated RP-ILD based on clinical manifestations and imaging features.

METHODS

A total of 103 patients with anti-MDA5+ DM were included. The patients were randomly split into training and testing sets of 72 and 31 patients, respectively. After image analysis, we collected clinical, imaging and radiomics features from each patient. Feature selection was performed first with the minimum redundancy and maximum relevance algorithm and then with the best subset selection method. The final remaining features comprised the radscore. A clinical model and imaging model were then constructed with the selected independent risk factors for the prediction of non-RP-ILD and RP-ILD. We also combined these models in different ways and compared their predictive abilities. A nomogram was also established. The predictive performances of the models were assessed based on receiver operating characteristics curves, calibration curves, discriminability and clinical utility.

RESULTS

The analyses showed that two clinical factors, dyspnoea (P = 0.000) and duration of illness in months (P = 0.001), and three radiomics features (P = 0.001, 0.044 and 0.008, separately) were independent predictors of non-RP-ILD and RP-ILD. However, no imaging features were significantly different between the two groups. The radiomics model built with the three radiomics features performed worse than the clinical model and showed areas under the curve (AUCs) of 0.805 and 0.754 in the training and test sets, respectively. The clinical model demonstrated a good predictive ability for RP-ILD in MDA5+ DM patients, with an AUC, sensitivity, specificity and accuracy of 0.954, 0.931, 0.837 and 0.847 in the training set and 0.890, 0.875, 0.800 and 0.774 in the testing set, respectively. The combination model built with clinical and radiomics features performed slightly better than the clinical model, with an AUC, sensitivity, specificity and accuracy of 0.994, 0.966, 0.977 and 0.931 in the training set and 0.890, 0.812, 1.000 and 0.839 in the testing set, respectively. The calibration curve and decision curve analyses showed satisfactory consistency and clinical utility of the nomogram.

CONCLUSION

Our results suggest that the combination model built with clinical and radiomics features could reliably predict the occurrence of RP-ILD in MDA5+ DM patients.

Serum ferritin as a significant biomarker for patients with idiopathic inflammatory myopathy-associated interstitial lung disease: A systematic review and meta-analysis

OBJECTIVE

The biomarkers for predicting the occurrence, progression, and death of idiopathic inflammatory myopathy-associated interstitial lung disease (IIM-ILD) remain unclear. Serum ferritin (SF) is a potential candidate and this systematic review and meta-analysis aimed to reveal the clinical significance of SF in IIM-ILD.

METHODS

Eligible English studies were selected from PubMed, Embase, Web of science and Scopus up to 9 June 2023. The SF levels in patients with IIM-ILD were extracted and pooled. Subgroup analysis was performed based on disease types, sensitivity analysis was conducted by excluding one class of literature at a time, and publication bias was assessed by funnel plot and Egger's test.

RESULTS

Pooled analysis of 1,933 patients with IIM from 19 studies showed that SF levels were significantly higher in IIM-ILD group (WMD=263.53ng/mL, 95% CI: 146.44-380.62, p<0.001) than IIM without ILD, subgroup analysis showed that SF levels in DM-ILD (WMD = 397.67ng/mL, 95% CI:142.84-652.50, p = 0.002) and PM/DM-ILD (WMD = 117.68 ng/mL, 95% CI: 86.32-149.04, p < 0.001) were significantly higher compared to those without ILD. SF levels were significantly higher in rapidly progressive interstitial lung disease group (RP-ILD)(WMD = 484.99 ng/mL, 95% CI: 211.12-758.87, p= 0.001) than chronic ILD(C-ILD) group, subgroup analysis showed that SF levels in DM-RP-ILD (WMD= 509.75 ng/mL, 95% CI: 215.34-804.16, p=0.001) were significantly higher than those in DM-C-ILD group. SF levels were significantly higher in death group (WMD= 722.16 ng/mL, 95% CI: 572.32-872.00, p< 0.001) compared to the survival group, subgroup analysis showed that death patients with DM-ILD(WMD= 735.62 ng/mL, 95% CI:574.92-896.32, p<0.001) and PM-ILD (WMD= 632.56 ng/mL, 95% CI:217.92-1047.19, p=0.003) had significantly higher SF levels than survival group respectively.

CONCLUSION

Increased SF levels can serve as a biomarker for predicting the occurrence, progression and death of patients with IIM-ILD, which can provide early warning sign for intervention and prognosis evaluation for IIM-ILD patients.

Autoimmune inflammatory myopathy biomarkers

The autoimmune inflammatory myopathy disease spectrum, commonly known as myositis, is a group of systemic diseases that mainly affect the muscles, skin and lungs. Biomarker assessment helps in understanding disease mechanisms, allowing for the implementation of precise strategies in the classification, diagnosis, and management of these diseases. This review examines the pathogenic mechanisms and highlights current data on blood and tissue biomarkers of autoimmune inflammatory myopathies.

Anti-MDA5 antibody-positive dermatomyositis: pathogenesis and clinical progress

Anti-melanoma differentiation-associated protein 5 (MDA5) antibody-positive dermatomyositis (MDA5-DM) is a subtype of dermatomyositis. Although the aetiology and pathology remain unclear, increasing evidence suggests that viral infection is a potential trigger of MDA5-DM. Multiple factors, including T cells, B cells, neutrophils and macrophages, are implicated in the pathophysiology of MDA5-DM. Distinctive skin rashes, rapidly progressive interstitial lung disease, peripheral lymphopenia and elevated serum ferritin levels are the most prominent clinical and laboratory features of MDA5-DM. Concomitant infection is a common complication of MDA5-DM. The proper evaluation of patients with MDA5-DM requires knowledge of the disease heterogeneity and clinical course variability. Several biomarkers, including serum levels of anti-MDA5 antibodies and biomarkers related to macrophage activation, have been identified as useful tools for monitoring disease activity and prognosis. MDA5-DM shows a poor response to conventional glucocorticoid and immunosuppressant therapy and has a poor overall prognosis. Therefore, there is an urgent need to explore the key pathogenic mechanisms of MDA5-DM and develop novel therapeutic options for patients. This Review discusses recent clinical progress and pathogenic findings of MDA5-DM.

MDA5-autoimmunity and Interstitial Pneumonitis Contemporaneous with the COVID-19 Pandemic (MIP-C)

Background

Anti-MDA5 (Melanoma differentiation-associated protein-5) positive dermatomyositis (MDA5 + -DM) is characterised by rapidly progressive interstitial lung disease (ILD) and high mortality. MDA5 senses single-stranded RNA and is a key pattern recognition receptor for the SARS-CoV-2 virus.

Methods

This is a retrospective observational study of a surge in MDA5 autoimmunity, as determined using a 15 muscle-specific autoantibodies (MSAs) panel, between Janurary 2018-December 2022 in Yorkshire, UK. MDA5-positivity was correlated with clinical features and outcome, and regional SARS-CoV-2 positivity and vaccination rates. Gene expression patterns in COVID-19 were compared with autoimmune lung disease and idiopathic pulmonary fibrosis (IPF) to gain clues into the genesis of the observed MDA5 + -DM outbreak.

Results

Sixty new anti-MDA5+, but not other MSAs surged between 2020-2022, increasing from 0.4% in 2019 to 2.1% (2020), 4.8% (2021) and 1.7% (2022). Few (8/60) had a prior history of confirmed COVID-19, peak rates overlapped with regional SARS-COV-2 community positivity rates in 2021, and 58% (35/60) had received anti-SARS-CoV-2 RNA vaccines. Few (8/60) had a prior history of COVID-19, whereas 58% (35/60) had received anti-SARS-CoV-2 RNA vaccines. 25/60 cases developed ILD which rapidly progression with death in 8 cases. Among the 35/60 non-ILD cases, 14 had myositis, 17 Raynaud phenomena and 10 had dermatomyositis spectrum rashes. Transcriptomic studies showed strong IFIH1 (gene encoding for MDA5) induction in COVID-19 and autoimmune-ILD, but not IPF, and IFIH1 strongly correlated with an IL-15-centric type-1 interferon response and an activated CD8+ T cell signature that is an immunologic hallmark of progressive ILD in the setting of systemic autoimmune rheumatic diseases. The IFIH1 rs1990760TT variant blunted such response.

Conclusions

A distinct pattern of MDA5-autoimmunity cases surged contemporaneously with circulation of the SARS-COV-2 virus during COVID-19. Bioinformatic insights suggest a shared immunopathology with known autoimmune lung disease mechanisms.

Risk factors for mortality in patients with anti-MDA5 antibody-positive dermatomyositis: A meta-analysis and systematic review

OBJECTIVES

To determine the prognostic factors of dermatomyositis with anti-melanoma differentiation-associated gene 5 (MDA5) antibody, a rare disease and often complicated by life-threatening, rapidly progressive interstitial lung disease.

METHODS

Herein, we searched the Medline, Embase, and Cochrane Library databases and extracted studies published before August 23, 2022. Pooled analysis of hazard ratios (HRs) or odds ratios was used to identify prognostic factors for mortality among patients with anti-MDA5 antibody-positive dermatomyositis (MDA5+ DM).

RESULTS

Twenty-nine cohorts with 2,645 patients were included in this meta-analysis. Factors related to poor prognosis included old age (HR 1.54, 95% confidence interval (CI) 1.41-1.69, p < 0.01), male sex (HR 2.07, 95% CI 1.34-3.18, p < 0.01), rapidly progressive interstitial lung disease (RP-ILD) (HR 9.34, 95% CI 6.39-13.6, p < 0.01), high levels of ferritin (HR 1.05, 95% CI 1.01-1.08, p < 0.01), C-reactive protein (CRP) (HR 1.12, 95% CI 1.06-1.19, p < 0.01), creatine kinase (HR 1.05, 95% CI 1.03-1.07, p < 0.01), and lactate dehydrogenase (LDH) (HR 1.27, 95% CI 1.12-1.45, p < 0.01), whereas oxygen index (HR 0.990, 95% CI 0.988-0.992, p < 0.01), partial pressure of oxygen (HR 0.933, 95% CI 0.906-0.961, p < 0.01), forced vital capacity (HR 0.962, 95% CI 0.928-0.998, p = 0.038), and lymphocyte count (HR 0.421, 95% CI 0.282-0.629, p < 0.01) were associated with better outcomes.

CONCLUSIONS

Old age, male sex, hypoxemia, low forced vital capacity, lymphocytopenia, and high levels of ferritin, CRP, creatine kinase, and LDH are risk factors for mortality in patients with MDA5+ DM. However, a cautious interpretation of these results and further quality investigation are warranted.

Polymyositis and dermatomyositis biomarkers

Polymyositis (PM) and dermatomyositis (DM) are the two subtypes of idiopathic inflammatory myositis and are characterized as symmetrical progressive muscle weakness in the proximal extremities. PM/DM affect multiple organs and systems, including the cardiovascular, respiratory and digestive tract systems. An in-depth understanding of PM/DM biomarkers will facilitate development of simple and accurate strategies for diagnosis, treatment, and prognosis prediction. This review summarized the classic biomarkers of PM/DM, including anti-aminoacyl tRNA synthetases (ARS) antibody, anti-Mi-2 antibody, anti-melanoma differentiation-associated gene 5 (MDA5) antibody, anti-transcription intermediary factor 1-γ (TIF1-γ) antibody, anti-nuclear matrix protein 2 (NXP2) antibody, among others. Among them, anti-aminoacyl tRNA synthetases antibody is the most classic. In addition, many potential novel biomarkers were also discussed in this review, including anti-HSC70 antibody, YKL-40, interferons, myxovirus resistance protein 2, regenerating islet-derived protein 3-α, interleukin (IL)-17, IL-35, microRNA (miR)-1 and so on. Among the biomarkers of PM/DM described in this review, classic biomarkers have become the mainstream biomarkers to assist clinicians in diagnosis due to their early discovery, in-depth research, and widespread application. The novel biomarkers also have potential and broad research prospects, which will make immeasurable contributions to exploring biomarker-based classification standards and expanding their application value.

Serum IgA levels for predicting the development of rapidly progressive interstitial lung disease in dermatomyositis

BACKGROUND

Some patients with dermatomyositis (DM) can develop rapidly progressive interstitial lung disease (RPILD) that is resistant to treatment and life-threatening. Convenient and practical predictive factors for the development of RPILD are currently lacking. We aimed to identify independent risk factors for RPILD in patients with DM.

METHODS

A total of 71 patients with DM admitted to our hospital between July 2018 and July 2022 were retrospectively reviewed. Risk factors to predict RPILD were identified by univariate and multivariate regression analyses, and significant variates for RPILD were included to establish a risk model.

RESULTS

Multivariate regression analysis revealed that the risk of RPILD was significantly associated with serum IgA levels. The area under the risk model curve, established by IgA levels combined with other independent predictors including the anti-melanoma differentiation-associated gene 5 (MDA5) antibody, fever, and C-reactive protein, was 0.935 (P < 0.001).

CONCLUSION

A higher serum IgA level was identified as an independent risk factor for RPILD in patients with DM.

Clinically Relevant Biomarkers in Connective Tissue Disease-Associated Interstitial Lung Disease

Interstitial lung disease (ILD) complicates connective tissue disease (CTD) with variable incidence and is a leading cause of death in these patients. To improve CTD-ILD outcomes, early recognition and management of ILD is critical. Blood-based and radiologic biomarkers that assist in the diagnosis CTD-ILD have long been studied. Recent studies, including -omic investigations, have also begun to identify biomarkers that may help prognosticate such patients. This review provides an overview of clinically relevant biomarkers in patients with CTD-ILD, highlighting recent advances to assist in the diagnosis and prognostication of CTD-ILD.

Successful treatment with tofacitinib for relapse of rapidly progressive interstitial lung disease in anti-melanoma differentiation-associated gene 5 antibody-positive clinically amyopathic dermatomyositis

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody is associated with clinically amyopathic dermatomyositis (CADM) with rapidly progressive interstitial lung disease (RP-ILD). Recently, several studies have reported that tofacitinib (TOF), a Janus kinase inhibitor, might be effective for cases of new or refractory RP-ILD in anti-MDA5 antibody-positive CADM; however, it is unknown whether TOF can also be effective for relapsed cases. We herein report a relapsed case of RP-ILD in anti-MDA5 antibody-positive CADM, which was successfully treated by combination therapy with TOF (5 mg twice daily). Our case suggests that TOF may also be a potential treatment option for relapsed cases of this disease.

MDA5 expression is associated with TGF-β-induced fibrosis: potential mechanism of interstitial lung disease in anti-MDA5 dermatomyositis

OBJECTIVES

This study aimed to investigate the high-resolution CT (HRCT) characteristics of anti-melanoma differentiation-associated gene 5 (MDA5) antibody positive dermatomyositis-associated interstitial lung disease (anti-MDA5 DM-ILD), and to clarify the underlying mechanisms of the clinical phenomenon.

METHODS

Clinical data and HRCT patterns were compared between anti-MDA5 DM-ILD (n = 32) and antisynthetase syndrome-associated ILD (ASS-ILD) (n = 29). RNA sequencing of whole-blood samples from the two groups, and in vitro experiments using human embryonic lung fibroblasts (HELFs) were conducted to explore the potential mechanisms of the clinical findings.

RESULTS

The anti-MDA5 DM-ILD subset had a significantly higher incidence of rapidly progressive ILD (RPILD) than ASS-ILD (65.6% vs 37.9%; P = 0.031). The relative percentage of the lung fibrosis HRCT pattern was significantly lower in the anti-MDA5 DM-ILD group, especially the RPILD subgroup (P = 0.013 and 0.003, respectively). RNA sequencing detected the upregulated genes including interferon-induced helicase C domain 1 (encoding MDA5), and a trend towards downregulated expression of TGF-β signalling components in anti-MDA5 DM-ILD. In vitro culture of HELFs revealed that upregulated expression of MDA5 in HELFs was correlated with the downregulated expression of alpha smooth muscle actin, connective tissue growth factor, collagen I and collagen III by suppressing the TGF-β signalling pathway.

CONCLUSIONS

Anti-MDA5 DM-ILD patients have significantly less lung fibrosis and elevated MDA5 expression. The upregulated expression of MDA5 has relations with the suppression of the pro-fibrotic function of fibroblasts via the TGF-β signalling pathway, which may partially explain the mechanism of the clinical phenomenon.

Roles of biomarkers in anti-MDA5-positive dermatomyositis, associated interstitial lung disease, and rapidly progressive interstitial lung disease

BACKGROUND

Anti-melanoma differentiation-associated gene 5 (MDA5)-positive dermatomyositis (MDA5⁺ DM) is significantly associated with interstitial lung disease (ILD), especially rapidly progressive ILD (RPILD) due to poor prognosis, resulting in high mortality rates. However, the pathogenic mechanism of MDA5⁺ DM-RPILD is unclear. Although some MDA5⁺ DM patients have a chronic course of ILD, many do not develop RPILD. Therefore, the related biomarkers for the early diagnosis, disease activity monitoring, and prediction of the outcome of RPILD in MDA5⁺ DM patients should be identified. Blood-based biomarkers are minimally invasive and can be easily detected.

METHODS

Recent relative studies related to blood biomarkers in PubMed were reviewed.

RESULTS

An increasing number of studies have demonstrated that dysregulated expression of blood biomarkers related to ILD such as ferritin, Krebs von den Lungen-6 (KL-6), surfactant protein-D (SP-D), and cytokines, and some tumor markers in MDA5⁺ DM may provide information in disease presence, activity, treatment response, and prognosis. These studies have highlighted the great potentials of blood biomarker values for MDA5⁺ DM-ILD and MDA5⁺ DM-RPILD. This review provides an overview of recent studies related to blood biomarkers, besides highlighted protein biomarkers, including antibody (anti-MDA5 IgG subclasses and anti-Ro52 antibody), genetic (exosomal microRNAs and neutrophil extracellular traps related to cell-free DNA), and immune cellular biomarkers in MDA5⁺ DM, MDA5⁺ DM-ILD, and MDA5⁺ DM-RPILD patients, hopefully elucidating the pathogenesis of MDA5⁺ DM-ILD and providing information on the early diagnosis, disease activity monitoring, and prediction of the outcome of the ILD, especially RPILD.

CONCLUSIONS

Therefore, this review may provide insight to guide treatment decisions for MDA5⁺ DM-RPILD patients and improve outcomes.

Bibliometric and altmetric analyses of publication activity in the field of idiopathic inflammatory myopathy in 2011-2021 based on web of science core collection databases

Idiopathic inflammatory myopathy is a multisystem autoimmune condition characterized by muscle inflammation (myositis) and interstitial lung disease (ILD). Bibliometric analysis and altmetric analysis are effective methods of evaluating academic productivity and measuring the influence of publications. The purpose of this study is to analyze the research productivity and influence of idiopathic inflammatory myopathy articles using bibliometric analysis and altmetric analysis. Data from articles published between 2011 and 2021 were obtained from the Web of Science. Altmetric attention scores and Mendeley reader counts of the articles were obtained from altmetric evaluations. In the study, 2060 articles related to idiopathic inflammatory myopathy were screened out showing an increasing trend in general. In terms of the origin countries of articles, the United States (n = 467, 22.67%) ranked first. Johns Hopkins University has the largest number of institutions (n = 113). The journals regarding idiopathic inflammatory myopathy and Rheumatology (n = 87) published the most articles. The most cited article was published by Mammen et al. and was related to autoantibodies. Dermatomyositis, polymyositis and other research hotspots were represented by keywords. The results of the altmetric analysis showed that citations, impact factors and h-index were significantly correlated with Altmetric Attention Scores and Mendeley Readers Count (P < 0.05). In summary, bibliometric analysis summarizes the current status of idiopathic inflammatory myopathy research and helps to understand the development of idiopathic inflammatory myopathy in the field between 2011 and 2021. Altmetric analysis was used to evaluate the academic and social influence of articles from the novel perspective of internet attention.

Risk Factors and Predictive Model for Dermatomyositis Associated with Rapidly Progressive Interstitial Lung Disease

Background

Rapidly progressive interstitial lung disease (RP-ILD) is a significant complication that determines the prognosis of dermatomyositis (DM). Early RP-ILD diagnosis can improve screening and diagnostic efficiency and provide meaningful guidance to carry out early and aggressive treatment.

Methods

A retrospective screening of 284 patients with DM was performed. Clinical and laboratory characteristics of the patients were recorded. The risk factors of RP-ILD in DM patients were screened by logistic regression (LR) and machine learning methods, and the prediction models of RP-ILD were developed by machine learning methods, namely least absolute shrinkage and selection operator (LASSO), random forest (RF), and extreme gradient boosting (XGBoost).

Results

According to the result of univariate LR, disease duration is a protective factor for RP-ILD, and ESR, CRP, anti-Ro-52 antibody and anti-MDA5 antibody are risk factors for RP-ILD. The top 10 important variables of the 3 machine learning models were intersected to obtain common important variables, and there were 5 common important variables, namely disease duration, LDH, CRP, anti-Ro-52 antibody and anti-MDA5 antibody. The AUC of LASSO, RF and XGBoost test set were 0.661, 0.667 and 0.867, respectively. We further validated the performance of these three models on validation set, and the results showed that, the AUC of LASSO, RF and XGBoost were 0.764, 0.727 and 0.909, respectively. Based on the results of the models, XGBoost is the optimal model in this study.

Conclusion

Disease duration, LDH, CRP, anti-Ro-52 antibody and anti-MDA5 antibody are vital risk factors for RP-ILD in DM. The prediction model constructed using XGBoost can be used for risk identification and early intervention in DM patients with RP-ILD and practical application.

Nailfold capillaries and myositis specific antibodies in anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis

OBJECTIVES

This study aimed to quantify nailfold capillary (NFC) abnormalities in anti-melanoma differentiation-associated gene 5 (MDA5)-positive dermatomyositis (DM) patients and to evaluate the association with clinical parameters, including serum biomarkers. In addition, we aimed to clarify the period leading to remission of NFC abnormalities during immunosuppressive treatment in patients with DM.

METHODS

A prospective observational study was conducted including patients (n = 10) who first visited Hiroshima University Hospital and were diagnosed with DM or clinically amyopathic dermatomyositis (CADM) with anti-MDA5 antibodies. We compared the NFC abnormalities detected by nailfold-video capillaroscopy (NVC), physical findings, blood tests, respiratory function tests, and vascular-related growth factors measured using a LEGENDplexTM Multi-Analyte Flow Assay Kit.

RESULTS

NFC abnormalities improved in all patients from 2-17 weeks after the initiation of immunosuppressive treatment. The NVC scores were inversely correlated with anti-MDA5 antibody titres at baseline. NVC scores and forced vital capacity (FVC) were positively correlated. Baseline with macrophage colony-stimulating factor (M-CSF) and stem cell factor (SCF) was correlated with anti-MDA-5 titres.

CONCLUSION

Our study suggests that NVC scores and disease activity are inversely correlated before treatment. Vascular-related growth factors, such as M-CSF and SCF, may be associated with the disease mechanism in patients with anti-MDA5 antibody-positive DM.

Biomarkers in Progressive Fibrosing Interstitial Lung Disease: Optimizing Diagnosis, Prognosis, and Treatment Response

Interstitial lung disease (ILD) comprises a heterogenous group of diffuse lung disorders that commonly result in irreversible pulmonary fibrosis. While idiopathic pulmonary fibrosis (IPF) is the prototypical progressive fibrosing ILD (PF-ILD), a high proportion of patients with other ILD subtypes develop a PF-ILD phenotype. Evidence exists for shared pathobiology leading to progressive fibrosis, suggesting that biomarkers of disease activity may prove informative across the wide spectrum of ILDs. Biomarker investigation to date has identified a number of molecular markers that predict relevant ILD endpoints, including disease presence, prognosis, and/or treatment response. In this review, we provide an overview of potentially informative biomarkers in patients with ILD, including those suggestive of a PF-ILD phenotype. We highlight the recent genomic, transcriptomic, and proteomic investigations that identified these biomarkers and discuss the body compartments in which they are found, including the peripheral blood, airway, and lung parenchyma. Finally, we identify critical gaps in knowledge within the field of ILD biomarker research and propose steps to advance the field toward biomarker implementation.

Antiviral proinflammatory phenotype of monocytes in anti-MDA5 antibody-associated interstitial lung disease

OBJECTIVE

To evaluate upstream and downstream regulators leading to macrophage activation and subsequent cytokine storm in patients with anti-melanoma differentiation-associated gene 5 (MDA5) antibody-associated interstitial lung disease (ILD).

METHODS

We conducted an integrated miRNA-mRNA association analysis using circulating monocytes from 3 patients with anti-MDA5-associated ILD and 3 healthy controls and identified disease pathways and a regulator effect network by Ingenuity Pathway Analysis (IPA). The expression of relevant genes and proteins was verified using an independent validation cohort, including 6 patients with anti-MDA5-associated ILD, 5 with anti-aminoacyl tRNA synthetase antibody-associated ILD, and 6 healthy controls.

RESULTS

IPA identified 26 matched pairs of downregulated miRNA and upregulated mRNAs and revealed that canonical pathways mediated by type I IFN signaling and C-C motif ligand 2 (CCL2) were responsible for the pathogenic process (P < 0.05 for all pathways). The regulatory network model identified IFN-β; Toll-like receptors 3, 7, and 9; and PU.1 as upstream regulators, while the downstream effect of this network converged at the inhibition of viral infection. mRNA and protein expression analysis using validation cohort showed a trend towards the increased expression of relevant molecules identified by IPA in patients with anti-MDA5-associated ILD compared with those with anti-aminoacyl tRNA synthetase antibody-associated ILD or healthy controls. The expression of all relevant genes in monocytes and serum levels of CCL2 and IFN-β declined after treatment in survivors with anti-MDA5-associated ILD.

CONCLUSION

An antiviral proinflammatory network orchestrated primarily by activated monocytes/macrophages might be responsible for cytokine storm in anti-MDA5-associated ILD.

Clinical impact of myositis-specific autoantibodies on long-term prognosis of juvenile idiopathic inflammatory myopathies: multicenter study

OBJECTIVES

This study aimed to investigate the clinical characteristics, treatment, and prognosis of juvenile idiopathic inflammatory myopathies (JIIM) in Japan for each myositis-specific autoantibody (MSA) profile.

METHODS

A multicenter, retrospective study was conducted using data of patients with JIIM at nine pediatric rheumatology centers in Japan. Patients with MSA profiles, determined by immunoprecipitation using stored serum from the active stage, were included.

RESULTS

MSA were detected in 85 of 96 cases eligible for the analyses. Over 90% of the patients in this study had one of the following three MSA types: anti-MDA5 (n = 31), anti-TIF1γ (n = 25), and anti-NXP2 (n = 25) antibodies. Gottron papules and periungual capillary abnormalities were the most common signs of every MSA group in the initial phase. The presence of interstitial lung disease (ILD) was the highest risk factor for patients with anti-MDA5 antibodies. Most patients were administered multiple drug therapies: glucocorticoids and methotrexate were administered to patients with anti-TIF1γ or anti-NXP2 antibodies. Half of the patients with anti-MDA5 antibodies received more than three medications including intravenous cyclophosphamide, especially patients with ILD. Patients with anti-MDA5 antibodies were more likely to achieve drug-free remission (29% vs 21%) and less likely to relapse (26% vs 44%) than others.

CONCLUSION

Anti-MDA5 antibodies are the most common MSA type in Japan, and patients with this antibody are characterized by ILD at onset, multiple medications including intravenous cyclophosphamide, drug-free remission, and a lower frequency of relapse. New therapeutic strategies are required for other MSA types.

Interstitial Lung Disease in Anti-MDA5 Positive Dermatomyositis

Anti-melanoma differentiation-associated gene 5-positive dermatomyositis (MDA5⁺ DM) is a rare autoimmune disease predominantly reported in East Asia. MDA5⁺ DM is an intractable disease with impressively high mortality due to rapid-progressive interstitial lung disease (RPILD). Other typical clinical manifestations comprise DM-specific rash (Gottron's papules, heliotrope rash) and amyopathic/hypomyopathic muscle involvement. Multiple prognostic factors have been identified. Baseline forced vital capacity (FVC) %-based staging could serve as a simplified risk stratification system. Serum biomarkers including MDA5 Ab titers, ferritin, KL-6 levels, and CD4⁺CXCR4⁺ T cell percentage could provide additional surrogate value of ILD severity and treatment response, as well as potential predictive value for survival. Spontaneous pneumomediastinum (PNM), ground-glass opacity (GGO), and consolidation were demonstrated to be the most significant features in pulmonary high-resolution computed tomography (HRCT) findings of MDA5⁺ DM-ILD. The semi-quantitative assessment of lesions in HRCT has also been demonstrated relevant to the outcome. The current treatment of this disease is still largely empirical. Immunosuppressive treatments, i.e., "triple therapy" (combination of high-dose glucocorticoids, tacrolimus, and intravenous cyclophosphamide) and JAK inhibitor-based therapy, are the mainstream regimens for MDA5⁺ DM-ILD, supported by the recently published trials. However, more efficacious regimen with favorable safety profile and high-level evidence is still urgently demanded for patients with MDA5⁺ DM-ILD, especially those at advanced-stage. We will summarize the terminology, etiology and pathogenesis, clinical features and outcome, prognostic factors, and treatment of MDA5⁺ DM-ILD in this review.

Predictive Features and Clinical Presentation of Interstitial Lung Disease in Inflammatory Myositis

Interstitial lung disease (ILD) represents one of the most severe extra-muscular features of idiopathic inflammatory myositis (IIM). We aimed to identify any clinical and serological predictors of ILD in a monocentric cohort of 165 IIM patients.

ILD+ patients were defined as having restrictive impairment in lung function tests and signs of ILD at chest high-resolution computed tomography (HRCT). Available HRCT images were centralized and classified in different ILD patterns: non-specific interstitial pneumonia (NSIP), organizing pneumonia (OP), usual interstitial pneumonia-like (UIP), indeterminate for UIP, and interstitial lung abnormalities (ILA). Lung function test data were recorded at onset, at 1 and 5 years after ILD diagnosis.

ILD was found in 52 IIM patients (31.5%): 46.2% was affected by anti-synthetase syndrome (ARS), 21% by polymyositis (PM), 19% by dermatomyositis (DM), and 13.5% by overlap myositis. Most of ILD+ showed NSIP (31.9%), OP (19%), indeterminate for UIP (19%), and UIP (12.8%) patterns. At multivariate analysis, ILD was predicted by anti-Ro52 (p: 0.0026) and dyspnea (p: 0.015) at IIM onset. Most of ILD onset within is 12 months after IIM. In five cases, ILD occurs after 12 months since IIM diagnosis: these patients more frequently show dry cough and anti-Ku antibodies. Anti-Ro52 + ILD patients showed a significant increase of DLCO at 1 and 5 years of follow-up, compared with anti-Ro52 negative cases.

ILD occurs in about one third of IIM and was predicted by dyspnea at onset and anti-Ro52 antibodies. Anti-Ro52 defines a subgroup of ILD showing a significant improvement of DLCO during follow-up.

This retrospective study has been approved by local ethic committee (ASST-Spedali Civili of Brescia, Italy); protocol number: NP3511