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

Anti- Melanoma Differentiation-Associated Gene 5 Antibody Positive Dermatomyositis: Recent Progress in Pathophysiology and Treatment

PURPOSE OF REVIEW

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis (MDA5-DM) is a rare systemic autoimmune disease characterized by a clinically amyopathic presentation and a high-risk association with rapidly progressive interstitial lung disease. Although frequently fatal, the underlying mechanisms remain incompletely understood. This review provides a comprehensive summary of recent advances in research on MDA5-DM, aiming to deepen our understanding of its pathogenic mechanisms and to accelerate future basic research that will contribute to the development of novel therapeutic strategies.

RECENT FINDINGS

Recent advancements have shed light on various aspects of this disease, including genetic and environmental factors contributing to disease susceptibility and the immunopathological processes and cytokine networks. Furthermore, significant progress has been made in understanding the pathogenicity, epitope recognition, and production mechanisms of anti-MDA5 antibodies, which have long been subjects of debate. On the therapeutic front, in addition to the conventional triple-combination regimen, emerging efficacy of JAK inhibitors and rituximab has been recognized. The development of biologics targeting lymphocytes offers additional hope for advancing therapeutic options. Advancing our understanding of the latest pathophysiological mechanisms of MDA5-DM is expected to pave the way for the development of safer and more effective therapeutic strategies.

The role of monocytes and macrophages in idiopathic inflammatory myopathies: insights into pathogenesis and potential targets

Idiopathic inflammatory myopathies (IIMs) are heterogeneous autoimmune disorders characterized by muscle inflammation, weakness, and extramuscular manifestations such as interstitial lung disease, skin rash, arthritis, dysphagia, myocarditis and other systemic organ involvement. Although T and B cells have historically been central to the understanding of IIM immunopathology, monocytes and their differentiated progenitor cells, macrophages, are increasingly being recognized as critical mediators of both tissue damage and repair. In subtypes such as dermatomyositis, immune-mediated necrotizing myopathy and antisynthetase syndrome, macrophages infiltrate skeletal muscle and other affected tissues, contributing to inflammation via production of pro-inflammatory cytokines, chemokines, and reactive oxygen species. Dysregulated interferon signaling, mitochondrial stress, and aberrant metabolic states in these cells further perpetuate tissue injury in IIMs. Conversely, certain macrophage subsets can support muscle fiber regeneration and dampen inflammation, underscoring the dual roles these cells can play. Future research into the heterogeneity of monocytes and macrophages, including single-cell transcriptomic and metabolomic approaches, will help clarify disease mechanisms, identify biomarkers of disease activity and prognosis, and guide novel therapeutic strategies targeting these innate immune cells in IIM.

Case report: Exploring efficacy of tofacitinib in modulating interferon response in five case of anti-MDA5+ dermatomyositis with interstitial lung disease

A case report highlights the challenges faced in managing a 66-year-old Chinese woman diagnosed with anti-MDA5 antibody-positive dermatomyositis (MDA5-DM) complicated by rapidly progressive interstitial lung disease (RP-ILD). Despite aggressive therapeutic interventions, her condition rapidly deteriorated, emphasizing the severity and devastating nature of this subtype of DM. A salient feature of her clinical presentation was the marked elevation of interferon (IFN)-γ and IFN-α levels, underscoring the pivotal role that IFNs play in driving the pathogenesis and progression of MDA5-DM-related RP-ILD. In an attempt to stem the relentless progression, tofacitinib, a Janus kinase (JAK) inhibitor, was applied into her treatment regimen. This therapeutic intervention led to a transient decrease in IFN-related cytokines, offering a glimpse of hope that JAK inhibition could modulate the exaggerated IFN response implicated in the disease. Other four similar cases underscore the critical importance of early and aggressive intervention in MDA5-DM patients, as well as the potential therapeutic avenues involving IFN blockers by JAK inhibitors. Urgent and well-designed clinical trials are imperative to unravel the intricate interplay between RP-ILD and the IFN signature in MDA5-DM, and to evaluate novel therapeutic targets that promise long-term efficacy and safety.

Pulmonary and serum cytokine profiles of patients with anti-ARS and anti-MDA5 antibodies

The present study aimed to determine the pulmonary cytokine profiles of patients with anti-RNA synthetase (ARS) and anti-melanoma differentiation-associated protein 5 (MDA5) antibodies. The study included patients with ARS and MDA5 whose serum or bronchoalveolar fluid (BALF) was available. Sandwich enzyme-linked immunoassay microarray multiplex assay was used to measure 18 cytokine levels in serum and BALF. The cytokine patterns were investigated using factor and cluster analyses. Pulmonary cytokine production was examined using the BALF/Seum cytokine ratio. Forty participants were enrolled in the study: 19 with ARS and 21 with MDA5. All patients had interstitial lung disease (ILD). BALF was collected from 10 patients with ARS and 6 with MDA5. Serum type 1 IFN, IP-10, MCP-1, and TNF-α were elevated in both ARS and MDA5. IL-6, IL-10, and IL-15 were elevated in MDA5. Serum cytokine patterns differed between ARS and MDA5. In BALF, IFN-α, IP-10, MCP-1, and ferritin were increased in both ARS and MDA5. Higher levels of IFN-α, IL-6, and ferritin were observed in MDA5. One patient with severe MDA5-ILD showed higher levels of multiple cytokines, including IL-6 and IFN-α. BALF cytokine patterns were similar in ARS and MDA5 cases except the one with severe MDA5-ILD. IL-6, IP-10, IL-15, MCP-1, and ferritin were produced in the lungs in ARS and MDA5 and IFN-α in MDA5. In conclusion, IFN-α and pulmonary macrophage activation play important roles in ILD development in both ARS and MDA5-ILD. MDA5-ILD could be characterized by higher production of multiple cytokines and macrophage activation, particularly in severe cases.

Monocyte-macrophage dynamics as key in disparate lung and peripheral immune responses in severe anti-melanoma differentiation-associated gene 5-positive dermatomyositis-related interstitial lung disease

BACKGROUND

Anti-melanoma differentiation-associated gene 5-positive dermatomyositis (anti-MDA5+ DM) is a rare inflammatory autoimmune disorder often complicated by life-threatening rapidly progressive interstitial lung disease (RP-ILD). The underlying mechanisms driving immune dysfunction and lung injury, however, remain poorly understood. The study aims to gain insights into the disrupted immune landscape in peripheral and pulmonary compartments of severe anti-MDA5+ DM and explore potential therapeutic targets.

METHODS

We employed single-cell RNA sequencing to examine cellular constituents within five patients' bronchoalveolar lavage fluid and paired peripheral blood mononuclear cells. Luminex assay and flow cytometry were further applied to validate the results.

RESULTS

Our analysis revealed starkly contrasting immune landscapes between the periphery and lungs, with peripheral immune suppression juxtaposed against pulmonary immune hyperactivation. Central to this dysregulation was the monocyte-macrophage lineage. Circulating monocytes exhibited an immunosuppressive phenotype, characterised by diminished cytokine production, reduced MHC II expression, and features resembling myeloid-derived suppressor cells. These monocytes were recruited to the lungs, where they differentiated into monocyte-derived alveolar macrophages (Mo-AMs) with robust proinflammatory and profibrotic activities. Mo-AMs drove cytokine storms and produced chemokines that amplified inflammatory cell recruitment and lung tissue remodelling. Additionally, peripheral T and NK cells exhibited increased cell death and active migration into the lungs, which may be the cause of lymphopenia.

CONCLUSIONS

Our study underscores the pivotal role of monocyte-macrophage dynamics in the immunopathogenesis of anti-MDA5+-associated RP-ILD, offering critical insights into compartment-specific immune dysregulation. These findings suggest potential therapeutic strategies targeting monocyte recruitment and macrophage activation to mitigate disease progression.

KEY POINTS

Peripheral immune suppression and pulmonary immune hyperactivation characterise the distinct immune landscapes in anti-MDA5+DM with RP-ILD. Circulating monocytes transition from an immunosuppressive phenotype in the periphery to proinflammatory and profibrotic Mo-AMs in the lungs. Chemokines produced by Mo-AMs drive monocyte and other immune cell recruitment to the lungs, amplifying pulmonary inflammation.

Increased serum level of IL-6 predicts poor prognosis in anti-MDA5-positive dermatomyositis with rapidly progressive interstitial lung disease

BACKGROUD

Anti-melanoma differentiation-associated protein 5 antibody-positive dermatomyositis (anti-MDA5-positvie DM) is a subtype of dermatomyositis with a poor prognosis, characterized by rapidly progressive interstitial lung disease (RP-ILD). The study aims to investigate the significance of serum cytokines profiles and peripheral lymphocytes in predicting prognoses of anti-MDA5-positvie DM with RP-ILD. Furthermore, it seeks to analyze longitudinal data of lymphocytes during hospitalization to identify distinct trajectories and cluster patients accordingly.

METHODS

A total of 168 patients with anti-MDA5-positive DM were enrolled in this retrospective study from two cohorts. Univariate and multivariate Cox regression analyses were conducted to determine the predictors of 6-month all-cause mortality and RP-ILD. Group-based trajectory modeling (GBTM) was employed to model the trajectories of longitudinal peripheral lymphocytes.

RESULTS

In the multivariate Cox regression analysis, IL-6 ≥ 13.41pg/mL, lymphocytes < 0.5 × 109 /L, lymphocytes from 0.5 to 1.0 × 109 /L, older age, and elevated LDH were identified as independent predictors of 6-month all-cause mortality. Furthermore, IL-6 ≥ 13.41pg/mL, lymphocytes < 0.5 × 109 /L, and lymphocytes from 0.5 to 1.0 × 109 /L were found to be independent predictors of RP-ILD. Additionally, three trajectory groups of lymphocytes within the first week after admission were established based on GBTM. These groups included: Group 1, with low-level of lymphocytes that declined; Group 2, with medium-level of lymphocytes that slightly rose; and Group 3, with high-level of lymphocytes that rose. Notably, group 1 showed the highest mortality (90.7%) and all experiencing RP-ILD. Increased expression of IL-6 in lung tissues was observed in two cases with RP-ILD compared to two cases without RP-ILD. We also found the increased infiltration of CD4 + and CD8 + T cells, particularly CD8 + T cells, in lung tissues from patients with RP-ILD.

CONCLUSIONS

Our study demonstrated that increased level of serum IL-6 (≥ 13.41pg/mL) and severe lymphopenia were promising predictors of 6-month all-cause mortality and the occurrence of RP-ILD in anti-MDA5-positive DM patients. Furthermore, tracking distinct trajectories of lymphocytes during hospitalization can be utilized to cluster patients.

Immunological characteristics of bronchoalveolar lavage fluid and blood across connective tissue disease-associated interstitial lung diseases

Interstitial lung disease (ILD) is a serious complication of connective tissue diseases (CTDs). The heterogeneity of ILDs reflects differences in pathogenesis among diseases. This study aimed to clarify the characteristics of CTD-ILDs via a detailed analysis of the bronchoalveolar lavage fluid (BALF) and blood immune cells. BALF and blood samples were collected from 39 Japanese patients with newly diagnosed ILD: five patients with Sjögren's syndrome (SS), eight patients with dermatomyositis (DM), six patients with rheumatoid arthritis (RA), six patients with systemic sclerosis, four patients with anti-neutrophil cytoplasmic antibody-associated vasculitis, and 10 patients with idiopathic interstitial pneumonia. We performed single-cell RNA sequencing to analyze the gene expression profiles in these patients' immune cells. In patients with SS, B cells in the BALF were increased and genes associated with the innate and acquired immunity were enriched in both the BALF and blood. In contrast, patients with DM showed an upregulation of genes associated with viral infection in both the BALF and blood. In patients with RA, neutrophils in the BALF tended to increase, and their gene expression patterns changed towards inflammation. These disease-specific characteristics may help us understand the pathogenesis for each disease and discover potential biomarkers.

A 72-year-old man with acute lung injury and anti-melanoma differentiation-associated gene 5 antibody: A case report

Anti-melanoma differentiation-associated gene 5 antibody (anti-MDA-5 Ab) is associated with amyopathic dermatomyositis (DM). These patients are particularly at high-risk for developing acute and rapidly progressive interstitial lung disease (ILD). Given the lack of muscle-related symptoms, along with its sudden onset and rapid clinical progression, the diagnosis of anti-MDA-5 Ab + ILD represents a challenge for clinicians. Even after the diagnosis is established, prognosis remains dismal owing to a hyperinflammatory state, mimicking cytokine storm, commonly refractory to potent immunosuppressive therapy. Hence, we present an elderly African American man who developed acute and rapidly progressive ILD in the setting of positive anti-MDA5 Ab, in whom lung histopathology was consistent with organizing phase of diffuse alveolar damage. Despite receiving combined immunosuppression with corticosteroids, cyclosporine, and cyclophosphamide, he developed irreversible lung injury within a month and was eventually referred for lung transplant evaluation.

Authentication and validation of key genes in the treatment of atopic dermatitis with Runfuzhiyang powder: combined RNA-seq, bioinformatics analysis, and experimental research

Background

Atopic dermatitis (AD) is inflammatory disease. So far, therapeutic mechanism of Runfuzhiyang powder on AD remains to be studied. This study aimed to mine key biomarkers to explore potential molecular mechanism for AD incidence and Runfuzhiyang powder treatment.

Methods

The control group, AD group, treat group (AD mice treated with Runfuzhiyang powder were utilized for studying. Differentially expressed AD-related genes were acquired by intersecting of key module genes related to control group, AD group and treatment group which were screened by WGCNA and AD-related differentially expressed genes (DEGs). KEGG and GO analyses were further carried out. Next, LASSO regression analysis was utilized to screen feature genes. The ROC curves were applied to validate the diagnostic ability of feature genes to obtain AD-related biomarkers. Then protein-protein interaction (PPI) network, immune infiltration analysis and single-gene gene set enrichment analysis (GSEA) were presented. Finally, TF-mRNA-lncRNA and drug-gene networks of biomarkers were constructed.

Results

4 AD-related biomarkers (Ddit4, Sbf2, Senp8 and Zfp777) were identified in AD groups compared with control group and treat group by LASSO regression analysis. The ROC curves revealed that four biomarkers had good distinguishing ability between AD group and control group, as well as AD group and treatment group. Next, GSEA revealed that pathways of E2F targets, KRAS signaling up and inflammatory response were associated with 4 biomarkers. Then, we found that Ddit4, Sbf2 and Zfp777 were significantly positively correlated with M0 Macrophage, and were significantly negatively relevant to Resting NK. Senp8 was the opposite. Finally, a TF-mRNA-lncRNA network including 200 nodes and 592 edges was generated, and 20 drugs targeting SENP8 were predicted.

Conclusion

4 AD-related and Runfuzhiyang powder treatment-related biomarkers (Ddit4, Sbf2, Senp8 and Zfp777) were identified, which could provide a new idea for targeted treatment and diagnosis of AD.

Exposome: Epigenetics and autoimmune diseases

Systemic autoimmune diseases are complex conditions characterized by an immune system dysregulation and an aberrant activation against self-antigens, leading to tissue and organ damage. Even though genetic predisposition plays a role, it cannot fully explain the onset of these diseases, highlighting the significant impact of non-heritable influences such as environment, hormones and infections. The exposome represents all those factors, ranging from chemical pollutants and dietary components to psychological stressors and infectious agents. Epigenetics, which studies changes in gene expression without altering the DNA sequence, is a crucial link between exposome and the development of autoimmune diseases. Key epigenetic mechanisms include DNA methylation, histone modifications, and non-coding RNAs. These epigenetic modifications could provide a potential piece of the puzzle in understanding systemic autoimmune diseases and their connection with the exposome. In this work we have collected the most important and recent evidence in epigenetic changes linked to systemic autoimmune diseases (systemic lupus erythematosus, idiopathic inflammatory myopathies, ANCA-associated vasculitis, and rheumatoid arthritis), emphasizing the roles these changes may play in disease pathogenesis, their potential as diagnostic biomarkers and their prospective in the development of targeted therapies.

Liver Involvement is Associated with Higher Risk of Rapidly Progressive Interstitial Lung Disease and Mortality in Anti-Melanoma Differentiation-Associated Gene 5 Antibody- Positive Dermatomyositis

Purpose

This study aimed to assess liver involvement and investigate its correlation with rapidly progressive interstitial lung disease (RP-ILD) and mortality in anti-melanoma differentiation-associated gene 5 antibody-positive (anti-MDA5 positive) DM patients.

Patients and Methods

This retrospective study included 159 patients diagnosed with anti-MDA5 positive DM or anti-synthetase syndrome (ASyS). Clinical features and laboratory findings were compared between patients with anti-MDA5 positive DM and patients with ASyS. In the anti-MDA5 positive DM cohort, clinical features and laboratory findings between patients with liver involvement and without liver involvement were further compared. The effects of liver involvement on the overall survival (OS) and development of RP-ILD were also analyzed using Kaplan-Meier method and Cox regression analysis.

Results

Levels of serum aspartate aminotransferase (AST), alanine transaminase (ALT), γ-glutamyl transferase (γGT) and alkaline phosphatase (ALP) were all significantly higher in patients with anti-MDA5 positive DM than those in patients with ASyS. In our cohort of anti-MDA5 positive DM patents, 31 patients (34.4%) were complicated with liver involvement. Survival analysis revealed that serum ferritin >1030.0 ng/mL (p<0.001), ALT >103.0 U/l (p<0.001), AST >49.0 U/l (p<0.001), γGT >82.0 U/l (p<0.001), ALP >133.0 U/l (p<0.001), lactate dehydrogenase (LDH)>474.0 U/l (p<0.001), plasma albumin (ALB) <35.7 g/l (p<0.001) and direct bilirubin (DBIL) >2.80 μmol/l (p=0.002) predicted poor prognosis. The incidence of RP-ILD increased remarkably in patients with liver involvement compared to patients without liver involvement (58.1% vs 22.0%, p=0.001). Multivariate analysis revealed that elevated serum ALT level was an independent risk factor for mortality (HR 6.0, 95% CI 2.3, 16.2, p<0.001) and RP-ILD (HR 5.9, 95% CI 2.2, 15.9, p<0.001) in anti-MDA5 positive DM patents.

Conclusion

Liver involvement is common in patients with anti-MDA5 positive DM. Elevated serum ALT level was an independent risk factor for RP-ILD and mortality in patients with anti-MDA5 positive DM.

Prognostic Role of Interferon-λ3 in Anti-Melanoma Differentiation-Associated Gene 5-Positive Dermatomyositis-Associated Interstitial Lung Disease

OBJECTIVE

Interferon-λ3 (IFNλ3) is a cytokine with antiviral functions on barrier surfaces, and it is associated with disease activity in autoimmune diseases. This study assessed the clinical significance of serum IFNλ3 levels in polymyositis/dermatomyositis (PM/DM)-associated interstitial lung disease (ILD).

METHODS

We measured serum IFNλ3 levels in 221 patients with PM/DM-ILD (155 in the derivation cohort, 66 in the validation cohort) and 38 controls. We evaluated factors associated with mortality risk among 79 patients with anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive DM-ILD.

RESULTS

Serum IFNλ3 levels at diagnosis were significantly higher in patients with PM/DM-ILD than in healthy controls. Remarkably, serum IFNλ3 levels were specifically increased in patients with anti-MDA5 antibody-positive DM-ILD in both the derivation and validation cohorts. In anti-MDA5 antibody-positive DM-ILD, patients with high IFNλ3 levels (>120 pg/mL) had significantly lower survival rates than those with low IFNλ3 levels (≤120 pg/mL). A multivariate analysis revealed that high IFNλ3 levels, as well as old age and low Pao2, were significantly associated with poor prognoses in patients with anti-MDA5 antibody-positive DM-ILD. In a classification analysis of patients with anti-MDA5 antibody-positive DM-ILD based on age, IFNλ3 level, and Pao2, patients with old age (>53 years), high IFNλ3 levels (>120 pg/mL), and low Pao2 (<75 mm Hg) had the worst survival. In lung pathologic analyses, IFNλ3-positive staining was observed in macrophages, airway epithelial cells, the pleural region, and intrapulmonary veins in patients with anti-MDA5 antibody-positive DM-ILD.

CONCLUSION

Serum IFNλ3 is a promising biomarker for identifying patients at high risk of poor outcomes in anti-MDA5 antibody-positive DM-ILD.

Autoimmunity against melanoma differentiation-associated gene 5 induces interstitial lung disease mimicking dermatomyositis in mice

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis (DM) is characterized by amyopathic DM with interstitial lung disease (ILD). Patients with anti-MDA5 antibody-associated ILD frequently develop rapidly progression and present high mortality rate in the acute phase. Here, we established a murine model of ILD mediated by autoimmunity against MDA5. Mice immunized with recombinant murine MDA5 whole protein, accompanied with complete Freund's adjuvant once a week for four times, developed MDA5-reactive T cells and anti-MDA5 antibodies. After acute lung injury induced by intranasal administration of polyinosinic-polycytidylic acid [poly (I:C)] mimicking viral infection, the MDA5-immunized mice developed fibrotic ILD representing prolonged respiratory inflammation accompanied by fibrotic changes 2 wk after poly (I:C)-administration, while the control mice had quickly and completely recovered from the respiratory inflammation. Treatment with anti-CD4 depleting antibody, but not anti-CD8 depleting antibody, suppressed the severity of MDA5-induced fibrotic ILD. Upregulation of interleukin (IL)-6 mRNA, which was temporarily observed in poly (I:C)-treated mice, was prolonged in MDA5-immunized mice. Treatment with anti-IL-6 receptor antibody ameliorated the MDA5-induced fibrotic ILD. These results suggested that autoimmunity against MDA5 exacerbates toll-like receptor 3-mediated acute lung injury, and prolongs inflammation resulting in the development of fibrotic ILD. IL-6 may play a key role initiating ILD in this model.

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

BACKGROUND

Melanoma differentiation-associated gene 5 (MDA5), as a cytoplasmic sensor for viral double-stranded RNAs, has received increasing attention in recent years. Although considerable headway has been made on the functional role of MDA5 in antiviral immunity and autoimmune disease, the available literature is insufficient to assess the vast field.

METHODS

This study performed a bibliometric analysis to investigate current hotspots in the global scientific output of MDA5 over the past two decades. Related publications and recorded information from 2002 to 2022 in the Web of Science Core Collection (WoSCC) database were retrieved. VOSviewer and CiteSpace were used for quantitative evaluation and visualization.

RESULTS

A total of 2267 original articles and reviews were obtained, and the annual number of publications related to MDA5 was increasing rapidly. China has published the most papers, while the USA was the most influential country with the most citations and the highest H-index. The Chinese Academy of Sciences, the United States Department of Health and Human Services, and the Journal of Virology were the most prolific research affiliation, funding source, and journal, respectively. Fujita T (Kyoto University) was the most productive author with the highest H-index and had close cooperation with Kato H and Yoneyama M. The keywords "RIG-I," "MDA5," "innate immunity," "double-stranded-RNA," and "recognition" had the highest frequency, while "dermatomyositis" as well as "autoantibody" seemed to be the emerging hotspots.

CONCLUSION

This study comprehensively demonstrated the research frontiers of MDA5 and will provide a useful resource for scholars to conduct future decisions.

KEY POINTS

We conducted the first in-depth survey of the research frontiers on melanoma differentiation-associated gene 5 (MDA5) over the past two decades via bibliometric analysis. We found that many early breakthroughs have been made in the mechanism of MDA5-mediated antiviral immune responses, and the role of MDA5 in autoimmune and autoinflammatory diseases has raised the recent concern. We identified that the virus infection-associated pathogenesis and effective therapeutic strategy of anti-MDA5 antibody-positive dermatomyositis will remain the hotspots in the future.

The efficacy and safety of tofacitinib in anti-melanoma differentiation-associated gene 5 antibody positive dermatomyositis associated interstitial lung disease: a systematic review and meta-analysis

BACKGROUND

The presence of anti-melanoma differentiation-associated gene 5 (MDA5) antibodies in dermatomyositis (DM) is associated with an increased risk of developing rapidly progressive interstitial lung disease (RP-ILD) and a poor prognosis.

OBJECTIVES

We aimed to explore whether tofacitinib could improve the prognosis of Anti-MDA5 antibody positive DM-interstitial lung disease (ILD).

DESIGN

Systematic review and meta-analysis.

DATA SOURCES AND METHODS

Studies were included if they compared mortality rate and infection events in patients with anti-MDA5 antibody positive DM-associated ILD who were treated with or without tofacitinib.

RESULTS

The systematic review and meta-analysis included a total of 148 patients from four cohort studies. Fifty-eight patients with anti-MDA5 antibody positive DM-ILD who received combined treatment-containing tofacitinib were enrolled in the experimental group. Additionally, 90 DM-ILD patients who did not receive tofacitinib-based therapy were included in the control group. The pooled risk ratio (RR) for all-cause mortality was 0.61 (95% CI, 0.41-0.91, p = 0.02) with I2 = 0 indicating no heterogeneity among the included studies. For virus infection risk, the pooled RR was 1.92 (95% CI, 0.90-4.10, p = 0.09), while bacterial and fungal infection-associated RRs were found to be 1.29 (95% CI, 0.65-2.55, p = 0.47) and 1.15 (95% CI, 0.46-2.89, p = 0.77), respectively. There was no statistically significant difference in infection risk between the two groups, and no heterogeneity was observed.

CONCLUSION

Our findings suggest that tofacitinib may reduce the risk of all-cause mortality in patients with anti-MDA5 antibody-positive DM-ILD without an increased risk of additional infections.

TRIAL REGISTRATION

PROSPERO: CRD42023445427; https://www.crd.york.ac.uk/prospero/.

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.

Dissociating Autoantibody Responses against Ro52 Antigen in Patients with Anti-Synthetase or Anti-MDA5 Antibodies

We aimed to dissociate the autoantibody response against the Ro52 protein in patients with anti-synthetase or anti-melanoma differentiation-associated gene 5 (MDA5) antibodies to explore the potential roles of different anti-Ro52 autoantibody responses in disease subclassification. This study used a single-center, prospective myositis cohort involving 122 consecutive patients with anti-synthetase antibodies identified by RNA immunoprecipitation (RNA-IP) and 34 patients with anti-MDA5 antibodies detected using enzyme immunoassay (EIA). Anti-Ro52 antibodies were measured using commercial EIA kits, while anti-Ro/SSA antibodies were identified using RNA-IP. Clinical features and outcomes were stratified according to two different patterns of autoantibody responses against Ro52, including "isolated anti-Ro52", defined by positive anti-Ro52 and negative anti-Ro/SSA antibodies, and "anti-SSA-Ro52", defined by positive anti-Ro52 and anti-Ro/SSA antibodies. Isolated anti-Ro52 positivity was the most prevalent autoantibody response in patients with both anti-synthetase (40/122; 32.8%) and anti-MDA5 antibodies (8/34; 23.5%). Isolated anti-Ro52 or anti-SSA-Ro52 positivity was associated with Gottron's sign in patients with anti-synthetase antibodies, while in patients with anti-MDA5 antibodies, isolated anti-Ro52 positivity was associated with respiratory insufficiency at initial presentation and poor overall survival. Isolated anti-Ro52 positivity could be a potential biomarker for patient stratification; however, the clinical significance of dissociating isolated anti-Ro52 positivity from overall anti-Ro52 positivity was not evident.

IFN-beta and EIF2AK2 are potential biomarkers for interstitial lung disease in anti-MDA5 positive dermatomyositis

OBJECTIVE

DM with positive anti-melanoma differentiation-related gene 5 (MDA5) antibody is an autoimmune disease with multiple complications. Interstitial lung diseases (ILDs) are significantly associated with DM and are particularly related to MDA5+ DM. This article aims to explore potential molecular mechanisms and develop new diagnostic biomarkers for MDA5+ DM-ILD.

METHODS

The series matrix files of DM and non-specific interstitial pneumonia (NSIP) were downloaded from the Gene Expression Omnibus (GEO) database to identify the differentially expressed genes (DEGs). Gene set enrichment analysis (GSEA) was used to screen the common enriched pathways related to DM and NSIP. Next, the co-expressed differential expressed genes (co-DEGs) between MDA5+, MDA5- and NSIP groups were identified by Venn plots, and then selected for different enrichment analyses and protein-protein interaction (PPI) network construction. The mRNA expression levels of IFN-beta and EIF2AK2 were measured by RT-qPCR. The protein expression levels of IFN-beta were measured by ELISA.

RESULTS

Using GSEA, the enriched pathway 'herpes simplex virus 1 infection' was both up-regulated in DM and NSIP. Enrichment analysis in MDA5+ DM, MDA5- DM and NSIP reported that the IFN-beta signalling pathway was an important influencing factor in the MDA5+ DM-ILD. We also identified that eukaryotic translation initiation factor 2 alpha kinase 2 (EIF2AK2) was an important gene signature in the MDA5+ DM-ILD by PPI analysis. The expression levels of IFN-beta and EIF2AK2 were significantly increased in MDA5+ DM-ILD patients.

CONCLUSIONS

IFN-beta and EIF2AK2 contributed to the pathogenesis of MDA5+ DM-ILD, which could be used as potential therapeutic targets.

Idiopathic inflammatory myopathy and non-coding RNA

Idiopathic inflammatory myopathies (IIMs) are common autoimmune diseases that affect skeletal muscle quality and function. The lack of an early diagnosis and treatment can lead to irreversible muscle damage. Non-coding RNAs (ncRNAs) play an important role in inflammatory transfer, muscle regeneration, differentiation, and regulation of specific antibody levels and pain in IIMs. ncRNAs can be detected in blood and hair; therefore, ncRNAs detection has great potential for diagnosing, preventing, and treating IIMs in conjunction with other methods. However, the specific roles and mechanisms underlying the regulation of IIMs and their subtypes remain unclear. Here, we review the mechanisms by which micro RNAs and long non-coding RNA-messenger RNA networks regulate IIMs to provide a basis for ncRNAs use as diagnostic tools and therapeutic targets for IIMs.

Identification of Unique microRNA Profiles in Different Types of Idiopathic Inflammatory Myopathy

Dermatomyositis (DM), antisynthetase syndrome (AS), immune-mediated necrotizing myopathy (IMNM), and inclusion body myositis (IBM) are four major types of idiopathic inflammatory myopathy (IIM). Muscle biopsies from each type of IIM have unique transcriptomic profiles. MicroRNAs (miRNAs) target messenger RNAs (mRNAs), thereby regulating their expression and modulating transcriptomic profiles. In this study, 18 DM, 12 IMNM, 6 AS, 6 IBM, and 6 histologically normal muscle biopsies underwent miRNA profiling using the NanoString nCounter system. Eleven miRNAs were exclusively differentially expressed in DM compared to controls, seven miRNAs were only differentially expressed in AS, and nine miRNAs were specifically upregulated in IBM. No differentially expressed miRNAs were identified in IMNM. We also analyzed miRNA-mRNA associations to identify putative targets of differentially expressed miRNAs. In DM and AS, these were predominantly related to inflammation and cell cycle progression. Moreover, our analysis showed an association between miR-30a-3p, miR-30e-3p, and miR-199b-5p downregulation in DM and the upregulation of target genes induced by type I interferon. In conclusion, we show that muscle biopsies from DM, AS, and IBM patients have unique miRNA signatures and that these miRNAs might play a role in regulating the expression of genes known to be involved in IIM pathogenesis.

Efficacy and Safety of Tofacitinib in Anti-Melanoma Differentiation-Associated 5 Gene Antibody-Positive Dermatomyositis

OBJECTIVES

This study aimed to evaluate the efficacy and safety of tofacitinib for the treatment of anti-melanoma differentiation-associated 5 gene (anti-MDA5) antibody-positive dermatomyositis (DM).

METHODS

This study included 52 patients with anti-MDA5 antibody-positive DM (MDA5 + DM) who were treated with tofacitinib and followed up. Clinical and laboratory data of these patients were recorded between January 2019 and June 2022. SPSS was used for all statistical analyses.

RESULTS

The mean age of patients with MDA5 + DM was 45 ± 12.4 years, and the median disease duration was 6.5 months (range, 3-13 months). The mean dosage of glucocorticoids was 34.7 ± 20.9 mg/d at the initiation of tofacitinib therapy. Overall, 47 patients were followed up for a mean duration of 7.8 ± 6.2 months. We found that the clinical symptoms of 28 patients (59.6%) were improved, but 1 patient (2.1%) died because of severe infection. Moreover, complications occurred in 25 patients (53.2%), among whom 19 patients had infections. Older age and C-reactive protein levels close to the upper value in reference range at the initial treatment were found to be the potential risk factors of infection. Furthermore, patients with cutaneous ulcers were found to have a lower risk of infection.

CONCLUSION

Tofacitinib can be used as a potential therapeutic option for MDA5 + DM. The occurrence of infection requires special attention during treatment, particularly in patients with older age and C-reactive protein levels close to the upper value in reference range.

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.

Type 1 interferon signature in peripheral blood mononuclear cells and monocytes of idiopathic inflammatory myopathy patients with different myositis-specific autoantibodies

Background

Myositis-specific autoantibodies (MSAs) are clinically used to diagnose and define idiopathic inflammatory myopathy (IIM) subsets. However, the underlying pathogenic mechanisms of patients with different MSAs remain unclear.

Methods

A total of 158 Chinese patients with IIM and 167 gender- and age-matched healthy controls (HCs) were enrolled. Transcriptome sequencing (RNA-Seq) was performed with peripheral blood mononuclear cells (PBMCs), followed by the identification of differentially expressed genes (DEGs) and analysis of gene set enrichment analysis, immune cell infiltration, and WGCNA. Monocyte subsets and related cytokines/chemokines were quantified. The expressions of interferon (IFN)-related genes were validated using qRT-PCR and Western blot in both PBMCs and monocytes. We also performed correlation analysis and ROC analysis to explore the potential clinical significance of the IFN-related genes.

Results

There were 1,364 genes altered in patients with IIM, including 952 upregulated and 412 downregulated genes. The type I interferon (IFN-I) pathway was remarkably activated in patients with IIM. Compared with patients with other MSAs, IFN-I signatures were significantly activated in patients with anti-melanoma differentiation-associated gene 5 (MDA5) antibodies. In total, 1,288 hub genes associated with IIM onset were identified using WGCNA, including 29 key DEGs associated with IFN signaling. The patients had more CD14brightCD16- classical, CD14brightCD16+ intermediate, and fewer CD14dimCD16+ non-classical monocyte subsets. Plasma cytokines like IL-6 and TNF and chemokines including CCL3 and MCPs increased. The validation of IFN-I-related gene expressions was consistent with the findings from RNA-Seq. The IFN-related genes were correlated with laboratory parameters and helpful for IIM diagnosis.

Conclusion

Gene expressions were remarkably altered in the PBMCs of IIM patients. Anti-MDA5+ IIM patients had a more pronounced activated IFN signature than others. Monocytes exhibited a proinflammatory feature and contributed to the IFN signature of IIM patients.

Plasma proteomic profiling reveals KRT19 could be a potential biomarker in patients with anti-MDA5+ dermatomyositis

OBJECTIVE

To investigate the immune response-related protein profiling in plasma of patients with idiopathic inflammatory myopathies (IIMs), especially in anti-MDA5+ dermatomyositis (DM).

METHODS

A total of 166 IIM patients and 107 healthy controls (HCs) were enrolled in our study. Ninety-two plasma immune response-related proteins were detected by Olink proteomics in 36 IIM patients and 25 HCs. The expression of plasma KRT19 was validated in another 130 IIM patients, 82 HCs, and 55 other rheumatic diseases.

RESULTS

A total of 46 differentially expressed proteins were detected, including 12 upregulated proteins and 34 downregulated proteins in IIM patients compared with HCs. Pathway analysis revealed lactoferrin danger signal response pathway, TLR4 signaling and tolerance, infection, and IL-10 signaling pathway were activated. The immune response-related protein profiling significantly altered in anti-MDA5+ DM patients, with LAMP3, HSD11B1, and KRT19 significantly increased, while SH2D1A, ITGA11, TRIM21, CD28, ITGB6, and HEXIM1 tremendously decreased. In addition, KRT19 was significantly increased in IIM patients, especially in anti-MDA5+ DM patients with the diagnostic value of a significant area under the ROC curve of 0.881.

CONCLUSION

Immune response-related proteins are significantly altered in patients with anti-MDA5+ DM patients. KRT19 could be a potential biomarker for anti-MDA5+ DM patients. Key Points • What is already known on this topic? Anti-MDA5+ DM is a distinctive subtype of IIM. Plasma immune response-related proteins panel needs to be investigated. • What this study adds? Plasma protein profiling of immune response-related proteins significantly altered in patients with idiopathic inflammatory myopathies (IIM), especially in anti-MDA5+ DM patients. • How this study might affect research, practice, or policy? KRT19 could be a potential biomarker in patients with anti-MDA5+ dermatomyositis.

Comparison of cytokine/chemokine profiles between dermatomyositis and anti-synthetase syndrome

Objectives

Dermatomyositis (DM) and anti-synthetase syndrome (ASS) are autoimmune diseases with multisystem involvement. Despite sharing some clinical and myopathological features, these are two diseases with different pathogeneses and prognoses. We aimed to clarify and compare cytokine/chemokine profiles in both disorders, which may help in the differential diagnosis.

Materials and methods

We collected clinical data and serum samples of consecutive patients with DM and ASS. Quantibody^® Human Inflammation Array 3 for cytokines/chemokines was performed in the serum of all participants. Receiver operating characteristic analysis with the area under the curve and Youden's index were performed.

Results

Eight newly diagnosed and treatment-naïve patients with DM, nine newly diagnosed and treatment-naïve patients with ASS, and 14 healthy controls were enrolled. Serum C-C motif chemokine ligand (CCL) 2, CCL4, C-X-C motif chemokine ligand (CXCL) 13, and tumor necrosis factor receptor 2 (TNFR2) were increased in patients with both DM and ASS. Serum interleukin (IL)-1 receptor type 1 (IL-1ra), IL-1b, CCL1, CXCL11, and CCL3 were modulated in patients with DM only, and IL-8, CXCL9, and tissue inhibitors of metalloproteinases-1 (TIMP-1) in patients with ASS only. Serum CCL2, CXCL13, and TNFR2 accurately distinguished patients with DM and ASS from healthy controls, as shown by the area under the curve >0.80. Moreover, receiver operating characteristic analysis showed that, as biomarkers for discrimination between DM and ASS, the combination of IL-1ra and TIMP-1, had an area under the curve of 0.944, a sensitivity of 87.5%, and a specificity of 88.9%.

Conclusion

Our study demonstrated that serum levels of cytokines/chemokines showed a different pattern in newly diagnosed patients with DM and ASS, in which serum IL-1ra and TIMP-1 could be used to distinguish between the two diseases.

Pathological Roles of Pulmonary Cells in Acute Lung Injury: Lessons from Clinical Practice

Interstitial lung diseases (ILD) are relatively rare and sometimes become life threatening. In particular, rapidly progressive ILD, which frequently presents as acute lung injury (ALI) on lung histopathology, shows poor prognosis if proper and immediate treatments are not initiated. These devastating conditions include acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF), clinically amyopathic dermatomyositis (CADM), epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI)-induced lung injury, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) infection named coronavirus disease 2019 (COVID-19). In this review, clinical information, physical findings, laboratory examinations, and findings on lung high-resolution computed tomography and lung histopathology are presented, focusing on majorly damaged cells in each disease. Furthermore, treatments that should be immediately initiated in clinical practice for each disease are illustrated to save patients with these diseases.

Predictors of progression in idiopathic inflammatory myopathies with interstitial lung disease

The idiopathic inflammatory myopathies (IIMs) are a group of connective tissue diseases that afect multiple organ systems, including the lungs. Interstitial lung disease (ILD) is the most common and heterogeneous complication of IIMs, with its degree ranging from mild to fatal. Thus, it is critical to identify clinical features and validated biomarkers for predicting disease progression and prognosis, which could be beneficial for therapy adjustment. In this review, we discuss predictors for rapid progression of IIM-ILD and propose guidance for disease monitoring and implications of therapy. Systematic screening of myositis-specific antibodies, measuring serum biomarker levels, pulmonary function tests, and chest high-resolution computer tomography will be beneficial for the evaluation of disease progression and prognosis.

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.

Tumor markers are associated with rapidly progressive interstitial lung disease in adult-dermatomyositis

OBJECTIVES

DM-associated rapidly progressive interstitial lung disease (DM-RP-ILD) has been the clinical conundrum. We assess the serum levels of tumor markers (TMs) in different types of ILD, and explore the diagnostic utility of TMs for DM/ADM-RP-ILD.

METHODS

This was a retrospective cohort study, data including clinical and laboratory records were collected from the first affiliated hospital of Zhengzhou University from December 2015, to June 2020. Tumor markers (TMs) include CEA, CA153, CA724, CA125, and CA199. Spearman analysis, ROC, and Kaplan-Meier curve were used for data analysis.

RESULTS

Total 272 patients (149 DM and 123 ADM) were enrolled, 152 (55.88%) with ILD (116 with chronic ILD, 36 with RP-ILD) and 120 (44.12%) without ILD among them. The serum levels of CEA and ferritin were significantly higher in patients with RP-ILD than in the other two groups. Serum CA125, CA199, and CA153 levels in patients with RP-ILD were higher than those without ILD. CEA levels were associated with the ferritin, KL-6 and anti-MDA5 levels, and CEA concentration was significantly negatively correlated with DLco (P = 0.016, R² =  - 0.281). CEA [AUC = 0.7, 95% CI = (0.594, 0.806)] and ferritin [AUC = 0.737, 95% CI = (0.614, 0.860)] had diagnosed value for patients developing RP-ILD. Patients with high serum CEA levels had higher mortality rate within the DM-ILD population.

CONCLUSIONS

TMs and ferritin were increased in DM/ADM-RP-ILD, and serum CEA and CA153 levels can evaluate disease severity of DM. And CEA and ferritin can be used as noninvasive diagnostic biomarkers for patients with DM-RP-ILD. Key Points • Interstitial lung disease (ILD) is a serious complication of DM, and is a leading cause of mortality, especially rapidly progressive ILD. • Tumor markers as a kind of noninvasive detection can reflect the disease severity of DM, and CEA and ferritin can be used to identify patients with RP-ILD.

Pathogenesis of Anti-melanoma Differentiation-Associated Gene 5 Antibody-Positive Dermatomyositis: A Concise Review With an Emphasis on Type I Interferon System

Anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis (MDA5+ DM) is typically characterized by cutaneous manifestations, amyopathic or hypomyopathic muscle involvement, and a high incidence of rapid progressive interstitial lung disease (RP-ILD). However, the exact etiology and pathogenesis of this condition has yet to be fully elucidated. Melanoma differentiation-associated gene 5 (MDA5), as the autoantigen target, is a member of the retinoic acid-inducible gene-I (RIG-I) family. The MDA5 protein can function as a cytosolic sensor that recognizes viral double-strand RNA and then triggers the transcription of genes encoding type I interferon (IFN). Therefore, it was presumed that viruses might trigger the overproduction of type I IFN, thus contributing to the development of MDA5+ DM. Emerging evidence provides further support to this hypothesis: the increased serum IFNα level was detected in the patients with MDA5+ DM, and the type I IFN gene signature was upregulated in both the peripheral blood mononuclear cells (PBMCs) and the skin tissues from these patients. In particular, RNA sequencing revealed the over-expression of the type I IFN genes in blood vessels from MDA5+ DM patients. In addition, Janus kinase (JAK) inhibitors achieved the promising therapeutic effects in cases with interstitial lung disease (ILD) associated with MDA5+ DM. In this review, we discuss the role of the type I IFN system in the pathogenesis of MDA5+ DM.

Low Circulating Monocytes Is in Parallel With Lymphopenia Which Predicts Poor Outcome in Anti-melanoma Differentiation-Associated Gene 5 Antibody-Positive Dermatomyositis-Associated Interstitial Lung Disease

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis (DM)-associated interstitial lung disease (ILD) may progress rapidly and lead to high mortality within 6 or 12 months. Except for reported prognostic factors, simple but powerful prognostic biomarkers are still in need in practice. In this study, we focused on circulating monocyte and lymphocyte counts and their variation tendency in the early stage of ILD. A total of 351 patients from two inception anti-MDA5 antibody-positive cohorts were included in this study, with various treatment choices. Lymphocyte count remained lower in the first month after admission in the non-survivor patients. Although baseline monocyte count showed no significant differences, average monocyte count in the following 4 weeks was also lower in the non-survivor group. Based on the C-index and analysis by the “survminer” R package in the discovery cohort, we chose 0.24 × 109/L as the cutoff value for Mono W0-2, 0.61 × 109/L as the cutoff value for lymph W0-2, and 0.78 × 109/L as the cutoff value for peripheral blood mononuclear cell (PBMC) W0-2, to predict the 6-month all-cause mortality. The Kaplan–Meier survival curves and adjusted hazard ratio with age, gender, and the number of immunosuppressants used all validated that patients with lower average monocyte count, lower average lymphocyte count, or lower average PBMC count in the first 2 weeks after admission had higher 6-month death risk, no matter in the validation cohort or in the pooled data. Furthermore, flow cytometry figured out that non-classical monocytes in patients with anti-MDA5 antibody-positive DM were significantly lower than healthy controls and patients with DM without anti-MDA5 antibodies. In conclusion, this study elucidated the predictive value of monocyte and lymphocyte counts in the early stage and may help rheumatologists to understand the possible pathogenesis of this challenging disease.

Clinical Value of 18F-FDG PET/CT Scan and Cytokine Profiles in Secondary Hemophagocytic Lymphohistiocytosis in Idiopathic Inflammatory Myopathy Patients: A Pilot Study

Background

Secondary hemophagocytic lymphohistiocytosis (sHLH) is a rare but fatal complication in idiopathic inflammatory myopathy (IIM) patients. The clinical value of radiological manifestations and serum cytokines remain unknown in this systemic crisis. This study aims to investigate the clinical value of PET/CT scan and cytokine profiles in predicting and understanding sHLH in IIM patients.

Methods

Adult IIM patients who were admitted to the four divisions of the First Affiliated Hospital, Zhejiang University School of Medicine (FAHZJU) from January 1, 2017 to December 31, 2020 were reviewed. PET/CT scan, cytokine profiles, and other factors of patients who met the inclusion and exclusion criteria were collected and analyzed.

Results

Sixty-nine out of 352 IIM patients were finally enrolled into the study. Ten patients developed sHLH and 70.0% of them died within 6 months. After false discovery rate (FDR) correction and multivariate logistic regression analysis, increased serum interferon (IFN)-γ level (p = 0.017), higher spleen mean standard uptake value (SUVmean, p = 0.035), and positivity of anti-MDA5 antibody (p = 0.049) were found to be significantly correlated with development of sHLH in IIM patients. The combination of serum IFN-γ, spleen SUVmean, and anti-MDA5 antibody found a balanced and satisfying predictor with a cutoff value of 0.047 and AUC of 0.946. A moderate correlation was identified between ferritin and spleen SUVmean (p = 0.001, r = 0.380) as well as serum IFN-γ(p = 0.001, r = 0.398). Before FDR correction, higher bilateral lung SUVmean (p = 0.034) and higher colon/rectum SUVmean (p = 0.013) were also observed in IIM patients who developed sHLH. By narrowing down to IIM patients with sHLH, anti-MDA5-antibody-positive DM patients tended to suffer from unfavorable outcome (p = 0.004) in Kaplan–Meier survival analysis.

Conclusion

Increased serum level of IFN-γ, elevated splenic FDG uptake, and positivity of anti-MDA5 antibody were significantly correlated with development of sHLH in IIM patients. Lung and lower digestive tract might also be affected due to systemic immune activation in IIM patients with sHLH. In addition, splenic FDG uptake, in combination with serum IFN-γand anti-MDA5 antibody, was found valuable in predicting development of sHLH in IIM patients. Among IIM patients with sHLH, anti-MDA5-antibody-positive DM patients showed higher tendency for unfavorable outcome.