Clinical manifestation and prognostic factor in anti-melanoma differentiation-associated gene 5 antibody-associated interstitial lung disease as a complication of dermatomyositis

Clinical and genetic analysis of macrophage activation syndrome complicating juvenile idiopathic inflammatory myopathies

BACKGROUND

Macrophage activation syndrome (MAS) is a serve complication of juvenile idiopathic inflammatory myopathies (JIIMs). This study delineates the clinical manifestations and genetic underpinnings of JIIM-MAS patients.

METHODS

We retrospectively analysed clinical and UNC13D gene from JIIM patients admitted to our centre between 2011 and 2021 to identify cases of MAS. Additionally, a literature review summarising reported cases of JIIMs and MAS was performed.

RESULTS

Of 773 JIIM patients, 10 (1.3%) were diagnosed with MAS. All patients presented with persistent fever and hyperferritinaemia. Seventy percent of patients met the HLH-2004 criteria, while 90% met the 2016 sJIA-MAS criteria. Most patients received combined treatment of corticosteroids and immunosuppressants. UNC13D gene analysis was performed in six patients. A homozygous pathogenic mutation (c.2588G>A) was detected in one patient with recurrent MAS, and twenty-eight single-nucleotide polymorphisms (SNPs) were detected. Eighty percent of patients exhibiting a consistent combination of ten SNPs compared to JIIM patients without MAS (35%).

CONCLUSION

MAS is an early and often overlooked complication of JIIMs. The 2016 sJIA-MAS criteria may facilitate early diagnosis. Combined corticosteroid and immunosuppressant therapy prove effective. An increased prevalence of UNC13D gene polymorphisms was observed in JIIM-MAS patients, highlighting the necessity for further investigations.

IMPACT

This study aimed to delineate the clinical manifestations and genetic underpinnings of macrophage activation syndrome (MAS) in ten patients with juvenile idiopathic inflammatory myopathies (JIIMs). MAS has been recognised as a complication of JIIMs. However, only a few case reports provide comprehensive descriptions of MAS in JIIM patients, and there are few reports related to UNC13D mutations in these patients. This article offers single-centre clinical insights to enhance the identification and management of MAS in JIIM patients, while also highlighting the potential association between MAS occurrence and UNC13D gene polymorphisms.

Characteristics of anti-melanoma differentiation associated gene 5 antibody-positive dermatomyositis with thrombotic microangiopathy

OBJECTIVES

Anti-melanoma differentiation associated gene 5 antibody (anti-MDA5 Ab)-positive dermatomyositis (DM) is a representative of rapidly progressive interstitial pneumonia. However, its association with thrombotic microangiopathy (TMA), characterized by thrombocytopenia, haemolytic anaemia, and organ dysfunction, has not been defined. This study aimed to elucidate the characteristics of anti-MDA5 Ab-positive DM accompanied by TMA.

METHODS

We reviewed our hospital records from November 2009 to September 2022. We included patients in accordance with the 2017 European League Against Rheumatism/American College of Rheumatology classification criteria and the criteria of Bohan and Peter. TMA was diagnosed according to the criteria for transplantation-associated TMA proposed by the International Working Group.

RESULTS

This study enrolled a total of 26 anti-MDA5 Ab-positive DM patients, four of whom developed TMA. The patients with TMA had an increased urine protein/creatinine ratio. In addition, these four of them showed significantly elevated levels of ferritin and anti-MDA5 Ab titers and were considered to have high disease activity; yet, all of them survived.

CONCLUSIONS

Our study indicated that anti-MDA5 Ab-positive DM patients with hyperferritinemia, a high anti-MDA5 Ab titer, and an increased urine protein/creatinine ratio should be carefully managed, bearing in mind a complication of TMA.

Clinical characteristics of idiopathic inflammatory myopathies patients with anti-PM/Scl antibodies

OBJECTIVES

To analyze the clinical features of idiopathic inflammatory myopathies (IIMs) patients with anti-PM/Scl antibodies.

METHODS

In this retrospective cohort study, we compared the clinical manifestations between patients who were solely positive for anti-PM/Scl antibodies (isolated anti-PM/Scl group) and those with a coexistence of anti-PM/Scl antibodies and myositis-specific antibodies (MSAs) (double-positive group).

RESULTS

Sixty-five IIMs patients positive for anti-PM/Scl antibodies were included, among whom 51 (78.5 %) were females, with a mean age of 49.1 years. Thirty-four (52.3 %) patients coexisted with MSAs. Compared to the double-positive group, the isolated anti-PM/Scl group demonstrated a higher proportion of women (90.3 % vs 67.6 %, p = 0.026) and a higher incidence of sclerodactyly (16.1 % vs 0, p = 0.021). Although there were no differences in the incidence of muscular weakness, dysphagia, or creatine kinase levels, thigh magnetic resonance imaging (MRI) revealed less muscle edema, atrophy, and fatty replacement in the isolated anti-PM/Scl group (p < 0.05). Interstitial lung disease (ILD) occurred in 80 % of patients, more frequently in the double-positive group (90.6 % vs 67.9 %, p = 0.028). According to HRCT, non-specific interstitial pneumonia (NSIP) was the most common pattern among anti-PM/Scl antibodies positive IIMs patients. The double-positive group exhibited higher ferritin levels, and a lower peripheral lymphocyte count (p < 0.05). The mortality rate in the double-positive group was higher than that in the isolated anti-PM/Scl group (20.6 % vs 0, p = 0.034).

CONCLUSION

Among IIMs patients who tested positive for anti-PM/Scl antibodies, ILD emerged as the predominant clinical feature, particularly when combined with MSA. Notably, patients with isolated anti-PM/Scl antibodies exhibited a favorable prognosis following immunotherapy.

[Diagnosis of anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis led by sarcoplasmic myxovirus resistance protein A expression on muscle pathology]

A 44-year-old woman with autism spectrum disorder developed bulbar symptoms and generalized muscle weakness 7 months before referral. Six months before, she was administered glucocorticoid for liver involvement. During the course, while she presented alopecia, skin ulcers, and poikiloderma, hyperCKemia was observed only twice. Due to complications including cardiac involvement and hearing loss as well, we suspected mitochondrial disease and performed a muscle biopsy. The muscle pathology showed sarcoplasmic myxovirus resistance A (MxA) expression with scattered pattern. Since anti-melanoma differentiation-associated gene 5 (MDA5) antibody was detected, we diagnosed the patient with anti-MDA5 antibody-positive dermatomyositis (DM). We reinforced immunosuppressive therapy, and her clinical symptoms and liver involvement were improved. When we diagnose a case of anti-MDA5 antibody-positive DM who is difficult to make clinical diagnosis, it may be valuable to evaluate sarcoplasmic MxA expression on muscle pathology.

Clinical utility of anti-Ro52 antibody confirmation in anti-MDA5 antibody-positive dermatomyositis: A case report

This case report highlights dermatomyositis (DM) characterised by the concurrent presence of anti-melanoma differentiation-associated protein 5 (anti-MDA5) and anti-Ro52 antibodies. A 64-year-old woman initially presented with erythema on the palms, which later spread to the dorsum of the hands, followed by involvement of the face, forehead, and upper eyelids. The patient reported joint pain, fatigue, and dyspnea. Physical examination revealed characteristic cutaneous manifestations, including heliotrope rash and Gottron's sign, accompanied by skin ulceration and muscle weakness. Blood tests showed elevated levels of creatine phosphokinase and C-reactive protein. A high-resolution computed tomography (HRCT) scan revealed interstitial lung disease (ILD) with an organising pneumonia (OP) pattern. Magnetic resonance imaging (MRI) confirmed the presence of myositis. Autoantibody analysis revealed concurrent positivity for both anti-MDA5 and anti-Ro52 antibodies. At the time of diagnosis, she had no respiratory impairment, but had an elevated C-reactive protein and high levels of anti-MDA5 antibody. She was started on triple combination therapy with glucocorticoids, cyclophosphamide, and tacrolimus. She had worsening oxygenation and elevated ferritin during the first weeks of treatment, but then her symptoms improved. Early detection of a co-positive anti-Ro52 antibody led to early initiation of triple combination therapy and a good prognosis.

Development of anti-MDA5 autoantibody-positive dermatomyositis following the use of etanercept biosimilar in rheumatoid arthritis

The induction of autoimmune diseases during tumour necrosis factor-alpha inhibitor (TNFi) usage has been described. Herein, we report a rare case of a 49-year-old woman with antimelanoma differentiation-associated gene 5 (MDA5) antibody (Ab)-positive dermatomyositis (DM), which developed 5 weeks after the introduction of an etanercept biosimilar to rheumatoid arthritis (RA). Four of the five known cases, including ours, of anti-MDA5Ab-positive DM complicated with RA revealed anti-MDA5Ab-positive DM following TNFi usage. When patients with RA are diagnosed with interstitial lung disease during TNFi usage, anti-MDA5 Ab-positive DM could be a differential diagnosis.

Unveiling the Connections Between Melanoma Differentiation-Associated Gene 5 (MDA5)-Positive Dermatomyositis and Its Potential Association With COVID-19: A Report of Two Cases

Dermatomyositis is a rare inflammatory condition affecting the skin, muscles, and joints. This series of anti-melanoma differentiation-associated gene 5 (anti-MDA5) autoantibody-positive cases highlights a possible link between anti-MDA5-positive dermatomyositis and COVID-19 exposure. A retrospective analysis was performed on anti-MDA5-positive dermatomyositis patients at a district general hospital between January 2021 and July 2023. Information was gathered on the clinical profiles, diagnostics, management, and disease course. The two cases are as follows: (1) A 44-year-old Asian female presented with back pain, tender proximal muscles, symmetrical synovitis, and Gottron's papules, which gradually began after a COVID vaccine and worsened after COVID-19 infection. Despite prompt management, she required finger amputation and a switch to immunomodulators to achieve arthritic disease control. (2) A 49-year-old Caucasian female presented with progressive dyspnea, polyarthralgia, dusky maculopapular rash, and oral ulcers, which began after a COVID vaccine and worsened after COVID-19 infection. Steroids and immunomodulators improved mobility and respiratory symptoms, while biologics subdued her skin symptoms. This case study provides growing evidence for an intriguing association between COVID-19 exposure and anti-MDA5 antibody-positive dermatomyositis. Further research is required to elucidate the underlying pathogenic mechanism. Early involvement of a multidisciplinary team, consideration of symptom variety, infection vigilance, and impact on quality of life are important factors for clinicians to consider when tailoring the management of these patients for optimized outcomes.

Effectiveness and safety of plasma exchange for anti-MDA5 antibody-positive clinically amyopathic dermatomyositis with rapidly progressive interstitial lung disease refractory to intensive immune suppression therapy: A case series

INTRODUCTION

Clinically amyopathic dermatomyositis (CADM) with anti-melanoma differentiation-associated gene 5 (MDA5) antibody (Ab) with rapidly progressive interstitial lung disease (RP-ILD) is often refractory for intensive immunosuppression. In this study, we verified the effectiveness and safety of plasma exchange (PEx) for this lethal disease.

METHODS

We retrospectively examined the clinical course and adverse effect (AE) of 12 patients with anti-MDA5 Ab-positive CADM between January 2017 and December 2021 in our hospital.

RESULTS

Five out of six patients treated with simple PEx using fresh frozen plasma or 5% albumin survived with or without home oxygen therapy. Multiple PEx (15-20 times) were required to achieve satisfactory improvement as well as remission of CADM. The AEs caused by PEx were resolved using conventional methods.

CONCLUSION

PEx might be a promising option for controlling the disease activity of anti-MDA5 Ab-positive CADM with severe RP-ILD and may contribute to better survival.

Unique characteristics of anti-MDA-5 associated dermatomyositis in Southern California with a large Hispanic population

OBJECTIVES

There is little to no data about the presentation and clinical course of anti-melanoma differentiation-associated gene-5 antibody (anti-MDA-5) dermatomyositis in a primarily U.S. Hispanic population. We describe the clinical course of anti-MDA-5 dermatomyositis in our majority Hispanic population.

METHODS

This is a multicenter, retrospective case series of anti-MDA-5 dermatomyositis. Patients diagnosed with anti-MDA-5 dermatomyositis from June 2015 to March 2023 at four medical centers in Los Angeles, California, were included. Demographics and clinical characteristics were obtained. Descriptive statistics, Pearson's chi-squared, Fisher's exact, Wilcoxon rank sum, and Kruskal-Wallis tests were performed as applicable.

RESULTS

Thirty anti-MDA-5 dermatomyositis patients were included. Twenty-two (73 %) were Hispanic. Twenty-one patients (70 %) were female, with a median age of 40.5 years. Hispanic patients were diagnosed with anti-MDA-5 dermatomyositis at a younger age than non-Hispanic patients (p = 0.025). Inflammatory arthritis was prominent; more males were affected than females (p = 0.027). Thirteen patients (43 %) were amyopathic. Twenty-five patients (83.3 %) had evidence of interstitial lung disease (ILD), and a higher ferritin level was associated with ILD (p = 0.049). There were six deaths (20 %); five (17 %) were ascribed to rapidly progressive ILD.

CONCLUSION

ILD was the most common presentation of anti-MDA-5 dermatomyositis in our cohort and was associated with higher ferritin levels. Hispanic patients had a younger age of diagnosis than non-Hispanic patients. Necrotic skin lesions and inflammatory arthritis were frequently seen. This is the first study looking at clinical phenotypes and outcomes of anti-MDA-5 dermatomyositis in a primarily Hispanic U.S.

POPULATION

Future studies are needed to better understand the clinical manifestations (to promptly recognize and treat) of this population of anti-MDA-5 dermatomyositis.

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.

Novel endotypes of antisynthetase syndrome identified independent of anti-aminoacyl transfer RNA synthetase antibody specificity that improve prognostic stratification

OBJECTIVES

To systemically analyse the heterogeneity in the clinical manifestations and prognoses of patients with antisynthetase syndrome (ASS) and evaluate the transcriptional signatures related to different clinical phenotypes.

METHODS

A total of 701 patients with ASS were retrospectively enrolled. The clinical presentation and prognosis were assessed in association with four anti-aminoacyl transfer RNA synthetase (ARS) antibodies: anti-Jo1, anti-PL7, anti-PL12 and anti-EJ. Unsupervised machine learning was performed for patient clustering independent of anti-ARS antibodies. Transcriptome sequencing was conducted in clustered ASS patients and healthy controls.

RESULTS

Patients with four different anti-ARS antibody subtypes demonstrated no significant differences in the incidence of rapidly progressive interstitial lung disease (RP-ILD) or prognoses. Unsupervised machine learning, independent of anti-ARS specificity, identified three endotypes with distinct clinical features and outcomes. Endotype 1 (RP-ILD cluster, 23.7%) was characterised by a high incidence of RP-ILD and a high mortality rate. Endotype 2 (dermatomyositis (DM)-like cluster, 14.5%) corresponded to patients with DM-like skin and muscle symptoms with an intermediate prognosis. Endotype 3 (arthritis cluster, 61.8%) was characterised by arthritis and mechanic's hands, with a good prognosis. Transcriptome sequencing revealed that the different endotypes had distinct gene signatures and biological processes.

CONCLUSIONS

Anti-ARS antibodies were not significant in stratifying ASS patients into subgroups with greater homogeneity in RP-ILD and prognoses. Novel ASS endotypes were identified independent of anti-ARS specificity and differed in clinical outcomes and transcriptional signatures, providing new insights into the pathogenesis of ASS.

Relationship between idiopathic interstitial pneumonias (IIPs) and connective tissue disease-related interstitial lung disease (CTD-ILD): A narrative review

While idiopathic interstitial pneumonia (IIP) centering on idiopathic pulmonary fibrosis (IPF) is the most prevalent interstitial lung disease (ILD), especially in the older adult population, connective tissue disease (CTD)-related ILD is the second most prevalent ILD. The pathogenesis of IPF is primarily fibrosis, whereas that of other ILDs, particularly CTD-ILD, is mainly inflammation. Therefore, a precise diagnosis is crucial for selecting appropriate treatments, such as antifibrotic or immunosuppressive agents. In addition, some patients with IIP have CTD-related features, such as arthritis and skin eruption, but do not meet the criteria for any CTD, this is referred to as interstitial pneumonia with autoimmune features (IPAF). IPAF is closely associated with idiopathic nonspecific interstitial pneumonia (iNSIP) and cryptogenic organizing pneumonia (COP). Furthermore, patients with iNSIP or those with NSIP with OP overlap frequently develop polymyositis/dermatomyositis after the diagnosis of IIP. Acute exacerbation of ILD, the most common cause of death, occurs more frequently in patients with IPF than in those with other ILDs. Although acute exacerbation of CTD-ILD occurs at a low rate of incidence, patients with rheumatoid arthritis, microscopic polyangiitis, or systemic sclerosis experience more acute exacerbation of CTD-ILD than those with other CTD. In this review, the features of each IIP, focusing on CTD-related signatures, are summarized, and the pathogenesis and appropriate treatments to improve the prognoses of patients with various ILDs are discussed.

Prognostic significance of natural killer cell depletion in predicting progressive fibrosing interstitial lung disease in idiopathic inflammatory myopathies

Objectives

Interstitial lung disease (ILD) is one of the common extramuscular involvement in idiopathic inflammatory myopathies (IIMs) (1). Several patients develop a progressive fibrosing ILD (PF-ILD) despite conventional treatment, resulting in a progressive deterioration in their quality of life (2). Here, we investigated the clinical and immune characteristics of IIM-ILD and risk factors for PF-ILD in IIM, mainly in anti-melanoma differentiation-associated protein 5 (anti-MDA5+) dermatomyositis (DM) and anti-synthetase syndrome (ASS).

Methods

Here, a prospective cohort of 156 patients with IIM-ILD were included in the longitudinal analysis and divided into the PF-ILD (n=65) and non-PF-ILD (n=91) groups, and their baseline clinical characteristics were compared. Univariate and multivariate Cox analyses were performed to identify the variables significantly associated with pulmonary fibrosis progression in the total cohort, then anti-MDA5+ DM and ASS groups separately.

Results

Peripheral blood lymphocyte counts, including T, B, and NK cell counts, were significantly lower in the PF-ILD group than in the non-PF-ILD group. This characteristic is also present in the comparison between patients with anti-MDA5+ DM and ASS. The multivariate Cox regression analysis revealed that age > 43.5 years [HR: 7.653 (95% CI: 2.005-29.204), p = 0.003], absolute NK cell count < 148 cells/μL [HR: 6.277 (95% CI: 1.572-25.067), p = 0.009] and absolute Th cell count < 533.2 cells/μL [HR: 4.703 (95% CI: 1.014-21.821), p = 0.048] were independent predictors of progressive fibrosing during 1-year follow-up for patients with anti-MDA5+ DM, while absolute count of NK cells < 303.3 cells/µL [HR: 19.962 (95% CI: 3.108-128.223), p = 0.002], absolute count of lymphocytes < 1.545×109/L [HR: 9.684 (95% CI: 1.063-88.186), p = 0.044], and ferritin > 259.45 ng/mL [HR: 6 (95% CI: 1.116-32.256), p = 0.037] were independent predictors of PF-ILD for patients with ASS.

Conclusions

Patients with anti-MDA5+ DM and ASS have independent risk factors for PF-ILD. Lymphocyte depletion (particularly NK cells) was significantly associated with PF-ILD within 1-year of follow-up for IIM-ILD.

Pretreatment mortality risk prediction model in patients with polymyositis/dermatomyositis-associated interstitial lung disease

OBJECTIVES

Risk prediction for patients with polymyositis/dermatomyositis-associated interstitial lung disease (PM/DM-ILD) is challenging due to heterogeneity in the disease course. We aimed to develop a mortality risk prediction model for PM/DM-ILD.

METHODS

This prognostic study analysed patients with PM/DM-ILD admitted to Nanjing Drum Hospital from 2016 to 2021. The primary outcome was mortality within 1 year. We used a least absolute shrinkage and selection operator (LASSO) logistic regression model to identify predictive laboratory indicators. These indicators were used to create a laboratory risk score, and we developed a mortality risk prediction model by incorporating clinical factors. The evaluation of model performance encompassed discrimination, calibration, clinical utility and practical application for risk prediction and prognosis.

RESULTS

Overall, 418 patients with PM/DM-ILD were enrolled and randomly divided into development (n=282) and validation (n=136) cohorts. LASSO logistic regression identified four optimal features in the development cohort, forming a laboratory risk score: C reactive protein, lactate dehydrogenase, CD3+CD4+ T cell counts and PO2/FiO2. The final prediction model integrated age, arthralgia, anti-melanoma differentiation-associated gene 5 antibody status, high-resolution CT pattern and the laboratory risk score. The prediction model exhibited robust discrimination (area under the receiver operating characteristic: 0.869, 95% CI 0.811 to 0.910), excellent calibration and valuable clinical utility. Patients were categorised into three risk groups with distinct mortality rates. The internal validation, sensitivity analyses and comparative assessments against previous models further confirmed the robustness of the prediction model.

CONCLUSIONS

We developed and validated an evidence-based mortality risk prediction model with simple, readily accessible clinical variables in patients with PM/DM-ILD, which may inform clinical decision-making.

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.

Spontaneous pneumomediastinum in anti-MDA5-positive dermatomyositis: Prevalence, risk factors, and prognosis

OBJECTIVE

To depict the clinical panorama of spontaneous pneumomediastinum (SPM) in anti-MDA5 antibody-positive dermatomyositis (anti-MDA5+ DM).

METHODS

A total of 1352 patients with idiopathic inflammatory myopathy (IIM), including 384 anti-MDA5+ DM patients were retrospectively enrolled. The clinical profiles of anti-MDA5+ DM-associated SPM were analyzed.

RESULTS

We identified that 9.4 % (36/384) of anti-MDA5+ DM patients were complicated with SPM, which was significantly higher than that of non-anti-MDA5+ DM and other IIM subtypes (P all <0.001). SPM developed at a median of 5.5 (3.0, 12.0) months after anti-MDA5+ DM onset. Anti-MDA5+ DM patients complicated with SPM showed a significantly higher frequency of fever, dyspnea, and pulmonary infection including viral and fungal infections compared to those without SPM (P all < 0.05). Cytomegalovirus (CMV) and fungal infections were identified to be independent risk factors for SPM development in the anti-MDA5+ DM. SPM and non-SPM patients in our anti-MDA5+ DM cohort showed comparable short-term and long-term survival (P = 0.236). Furthermore, in the SPM group, we found that the non-survivors had a lower peripheral lymphocyte count, higher LDH level, and higher frequency of intensification of immunosuppressive treatment (IST) than survivors. The elevated LDH level and intensification of IST were independent risk factors for increased mortality in anti-MDA5+ DM-associated SPM patients.

CONCLUSIONS

Nearly one-tenth of patients with anti-MDA5+ DM develop SPM. Both CMV and fungal infections are risk factors for SPM occurrence. The development of SPM does not worsen the prognosis of anti-MDA5+ DM patients, and the intensification of IST does harm to the SPM prognosis.

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.

Disease-associated immune cell endotypes in anti-MDA5-positive dermatomyositis using unbiased hierarchical clustering

Objective

Clinical and prognostic features of Anti-MDA5-Positive Dermatomyositis (MDA5+ DM) are diverse. This study aimed to examine the peripheral immune cell profiles of patients with MDA5+ DM, identify disease endotypes related to the heterogeneous manifestations and prognosis, and guide individualized therapy regimen.

Methods

This inpatient cohort included 123 patients with MDA5+ DM. Unsupervised hierarchical clustering analysis was used to derive disease endotypes from the circulating immune cell profiles on admission. Clinical symptoms, laboratory test results, inpatient treatments, and disease outcomes were then analyzed among the identified endotypes.

Results

Three disease endotypes in MDA5+ DM were identified from peripheral immune cell profiles. Endotype1 had the highest percentages of CD4+ T cells and monocytes, and the lowest percentage of neutrophils; Endotype2 had the highest percentage of B cells; Endotype3 had the highest percentage of CD8+ T cells and NK cells. Clinical and prognostic heterogeneity of the endotypes were revealed. Endotype1 had the lowest 3-month mortality with the high incidence of periungual capillary changes. Endotype2 and Endotype3 had higher prevalence of rapidly progressive interstitial lung disease (RPILD) and mortality at 3 months than Endotype1. Meanwhile, Endotype3 had higher pneumocystis jiroveci and CMV viremia cases with significantly elevated of activated CD8+ T cells and multiple cytokines than Endotype1.

Conclusion

Clustering analysis of peripheral immune cell profiles identified three different endotypes in MDA5+ dermatomyositis. Endotpye2 and 3 showed higher RPILD, 3-month mortality, pneumocystis jiroveci and CMV viremia.

Successful Treatment of Rapidly Progressive Interstitial Lung Disease in Juvenile Dermatomyositis

Juvenile dermatomyositis (JDM) is a rare systemic autoimmune disease characterized by cutaneous findings, muscle inflammation, and vasculopathy. Patients with antimelanoma differentiation associated gene 5 (anti-MDA5) JDM may have subtle muscle weakness, absence of pathognomonic rashes, and more polyarthritis and ulcerative skin lesions when compared with other JDM subtypes. Although there is a known association of rapidly progressive interstitial lung disease (RP-ILD) in patients with anti-MDA5 dermatomyositis, few case reports describe this association in the pediatric literature. Even fewer reports describe successful treatment. We report an unusual case of RP-ILD in a pediatric patient with a hypomyopathic presentation complicated by prolonged intubation and pulmonary hemorrhage. A 4-year-old underweight female presented in respiratory distress and quickly progressed to severe hypoxic and hypercarbic respiratory failure requiring intubation. She experienced fatigue, intermittent fever, and transaminitis. The diagnosis was delayed because of recent travel history and a lack of typical cutaneous features of JDM, except a small erythematous papule on her antihelix. Her pulmonary hemorrhage and ear lesion prompted additional rheumatic workup. The myositis-specific antibody panel revealed high positive anti-MDA5 antibodies that prompted aggressive combination therapy with plasmapheresis, systemic steroids, inhibitors of Janus kinase, agents to deplete B-cells, and intravenous immunoglobulin. The patient responded well to treatment and was ultimately extubated and discharged. To our knowledge, this is the first thoroughly documented case of anti-MDA5 JDM with RP-ILD presenting with pulmonary hemorrhage and lacking typical cutaneous features. Early recognition of this highly fatal condition is important for improved prognosis.

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.

[Current update on dermatomyositis]

Dermatomyositis (DM) is a rare autoimmune disease with involvement of skin and muscle that is classified as an idiopathic inflammatory myopathy. In addition to cutaneous lesions as well as weakness and atrophy of muscles, the heart and lungs are the major affected organs. DM occurs in association with malignant tumors in 20% of affected adults. The pathogenesis of the disease is not completely understood. DM is a multifactorial disease influenced by genetic, environmental and immunological factors. The immune response is characterized by activation of innate and adaptive immune mechanisms and a strong activation of the type I interferon pathway. Myositis-specific antibodies are characteristic of DM and allow differential diagnosis. Therapies include corticosteroids, antimalarials, immunoglobulins, biologics such as rituximab or JAK inhibitors. Early diagnosis and treatment are essential for the prognosis.

Disease patterns and specific trajectories of anti-MDA5-related disease: a multicentre retrospective study of 70 adult patients

Introduction

This study aimed to provide an updated analysis of the different prognostic trajectories of patients with anti-melanoma differentiation-associated gene 5 (MDA5) antibodies.

Methods

Among a cohort of 70 patients, baseline characteristics and phenotypes, treatments and outcomes were analyzed. A Cox proportional hazards model was used to identify factors associated with poor outcomes, i.e., death or progressive disease at the last follow-up.

Results

Among the 70 patients, 45 were women, and 54 were Caucasian. A dermatologic involvement was observed in 58 (83%) patients, including 40 with MDA5 vasculopathy-related skin lesions. Muscular involvement was observed in 39 (56%) patients. Interstitial lung disease (ILD) was observed at baseline in 52 (74%) patients, including 23 (44%) who developed rapidly progressive (RP) ILD. Seven (10%) patients showed thromboembolic complications within the first weeks of diagnosis, and eight (11%) other patients developed a malignancy (4 before the diagnosis of anti-MDA5 disease). Poor outcomes were observed in 28 (40%) patients, including 13 (19%) deaths. Among the 23 patients with RP-ILD, 19 (79%) showed poor outcomes, including 12 (63%) who died. In multivariate analyses, RP-ILD (hazard ratio (HR), 95% CI: 8.24 [3.21-22], p<0.0001), the occurrence of thromboembolic events (HR: 5.22 [1.61-14.77], p=0.008) and the presence of any malignancy (HR: 19.73 [6.67-60], p<0.0001) were the three factors independently associated with poor outcomes.

Discussion

This new independent cohort confirms the presence of different clinical phenotypes of anti-MDA5 diseases at baseline and the poor prognosis associated with RP-ILD. Thromboembolic events and malignancies were also identified as prognostic factors.

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.

Aggressive multi-combination therapy for anti-MDA5 antibody-positive dermatomyositis-rapidly progressive interstitial lung disease

OBJECTIVES

To elucidate the efficacy and safety of aggressive multi-combination therapy with mycophenolate mofetil, rituximab, and plasma exchange or polymyxin B immobilized fiber column direct hemoperfusion followed by conventional therapy with corticosteroids, calcineurin inhibitors, and intravenous pulse cyclophosphamide in patients with rapidly progressive interstitial lung disease (RPILD) with anti-melanoma differentiation-associated gene 5 (MDA5)-antibody-positive dermatomyositis (DM).

METHODS

A total of 23 patients with anti-MDA5 antibody-positive DM-RPILD were enrolled, with nine patients in Group A (treated conventionally before March 2015) and 14 patients in Group B (received aggressive treatment after April 2015).

RESULTS

Pretreatment severity of interstitial lung disease (ILD) did not differ between the two groups. However, Group B exhibited a higher cumulative survival rate at 48 weeks than Group A (64.3% vs. 33.3%). The corticosteroid dose, divided by the initial dose at 3 months and 12 months, was significantly lower in Group B than in Group A (p = .046 and .026, respectively). Among the ILD-related deaths in Group B, there was a tendency toward a higher proportion of males and more severe ILD. The incidence of infection did not differ between the groups, but leukopenia was more common in Group B.

CONCLUSION

This aggressive multi-combination therapy may improve the survival outcome of patients with anti-MDA5 antibody-positive DM-RPILD. However, careful management of complications, such as opportunistic infections and leukopenia, is essential. Future refinement through longitudinal investigations tracking the long-term efficacy, safety, and cost-effectiveness of this treatment strategy is needed.

Comparison of characteristics and anti-MDA5 antibody distribution and effect between clinically amyopathic dermatomyositis and classic dermatomyositis: a retrospective case-control study

Background

Clinically amyopathic dermatomyositis (CADM) is a distinct subtype of dermatomyositis (DM) characterized by typical DM cutaneous findings but with minimal or no evidence of myositis. It possesses unique features different from classic DM (CDM). Anti-melanoma differentiation-associated gene 5 (MDA5) antibodies were found in CADM and are thought to increase the risk of rapidly progressive interstitial lung disease (RP-ILD) and are present in both CADM and CDM patients, affecting their condition and prognosis. Nevertheless, no large-sample studies have compared all aspects concerning patients with CADM and those with CDM. This study aimed to investigate differences in clinical characteristics and risk factors for mortality between CADM and CDM and to clarify the distribution and impact of anti-MDA5 antibodies in patients with these conditions.

Methods

A retrospective case-control study included 330 patients and collected and analyzed their clinical data from The First Affiliated Hospital of Shandong First Medical University and Shandong Provincial Hospital of Traditional Chinese Medicine between January 2015 and July 2022; all patients were followed up to evaluate changes in their condition and prognosis. Several new cohorts were designed around anti-MDA5 antibodies to explore their distribution and impact in CADM and CDM.

Results

We found CADM to be associated with higher rates of mortality, 1-year mortality, interstitial lung disease (ILD), and RP-ILD than CDM. In CADM, RP-ILD, anti-MDA5 antibodies, and high ferritin and lactate dehydrogenase (LDH) levels were identified as independent risk factors for death. In CDM, the neutrophil-to-lymphocyte ratio, anti-MDA5 antibodies, and high ferritin levels were shown to be independent risk factors for death, whereas mechanic's hand was considered a protective factor against it. Anti-MDA5 antibody-positive patients did not exhibit any significant difference based on whether they belonged to the CADM or CDM groups. When no anti-MDA5 antibody-positive patients participated, the ferritin levels and rates of RP-ILD and ILD were still higher in CADM than in CDM; however, such differences decreased, whereas the LDH levels, rates of mortality, and 1-year mortality did not differ. Anti-MDA5 antibody-positive patients consistently showed higher LDH and ferritin levels, lower lymphocyte levels, higher probability of RP-ILD and ILD, and worse prognosis than anti-MDA5 antibody-negative patients, irrespective of whether the patients had DM, CADM, or CDM.

Conclusion

Patients with CADM exhibit relatively worse symptoms, serological findings, and prognosis than those with CDM. Furthermore, patients with CADM and those with CDM have commonalities and differences in risk factors for death. Moreover, CADM may necessitate earlier and more aggressive treatment strategies than CDM. Anti-MDA5 antibodies occur at a high level in patients with CADM, not only affecting the symptoms and prognosis of DM but also having a non-negligible impact on the differences between CADM and CDM. Hence, screening for anti-MDA5 antibodies in patients with CADM and CDM is extremely essential.

Long-Term Prognosis of Antimelanoma Differentiation-Associated Gene 5-Positive Dermatomyositis With Interstitial Lung Disease

OBJECTIVE

Antimelanoma differentiation-associated gene 5 (anti-MDA5)-positive dermatomyositis with interstitial lung disease (DM-ILD) progresses rapidly and has a poor prognosis. Previously, we reported the efficacy of a combination therapy comprising high-dose glucocorticoids (GCs), calcineurin inhibitors (CNIs), and intravenous cyclophosphamide (IV CYC) in a multicenter clinical trial (UMIN000014344). In the present study, we evaluated the long-term outcomes and effects of induction therapy on the maintenance of remission.

METHODS

All participants from our previous trial were followed up for > 5 years. Seventy-three other patients with anti-MDA5-positive DM-ILD from our institute were retrospectively integrated into the previous trial for further analysis. Sixty-eight patients achieved remission and survived for > 6 months. Based on the induction treatment, we classified the patients into 2 groups: (1) group T (n = 56), with triple combination therapy (GCs, CNIs, and IV CYC), and (2) group C (n = 12), with monotherapy/dual therapy. The recurrence-free and drug-withdrawal rates of immunosuppressive agents were compared.

RESULTS

The overall survival and recurrence-free survival rates at 5 years were 100% for the participants in the previous trial. The 5-year cumulative withdrawal rates for CNIs and GCs were 70% and 53%, respectively. In a comprehensive analysis, the recurrence-free rates in group T were higher than those in group C (90% vs 56%; P < 0.05). The drug-withdrawal rates of CNIs and GCs at 10 years in group T were also higher than those in group C (79% vs 0% and 43% vs 0%, respectively; P < 0.05).

CONCLUSION

Triple combination therapy in the induction phase can reduce the risk of recurrence and facilitate drug withdrawal in anti-MDA5-positive DM-ILD.

The molecular mechanism underlying dermatomyositis related interstitial lung disease: evidence from bioinformatic analysis and in vivo validation

Background

Dermatomyositis (DM) is an autoimmune and inflammatory disease that can affect the lungs, causing interstitial lung diseases (ILD). However, the exact pathophysiological mechanisms underlying DM-ILD are unknown. Idiopathic pulmonary fibrosis (IPF) belongs to the broader spectrum of ILD and evidence shows that common pathologic pathways might lie between IPF and DM-ILD.

Methods

We retrieved gene expression profiles of DM and IPF from the Gene Expression Omnibus (GEO) and utilized weighted gene co-expression network analysis (WGCNA) to reveal their co-expression modules. We then performed a differentially expressed gene (DEG) analysis to identify common DEGs. Enrichment analyses were employed to uncover the hidden biological pathways. Additionally, we conducted protein-protein interaction (PPI) networks analysis, cluster analysis, and successfully found the hub genes, whose levels were further validated in DM-ILD patients. We also examined the relationship between hub genes and immune cell abundance in DM and IPF. Finally, we conducted a common transcription factors (TFs)-genes network by NetworkAnalyst.

Results

WGCNA revealed 258 intersecting genes, while DEG analysis identified 66 shared genes in DM and IPF. All of these genes were closely related to extracellular matrix and structure, cell-substrate adhesion, and collagen metabolism. Four hub genes (POSTN, THBS2, COL6A1, and LOXL1) were derived through intersecting the top 30 genes of the WGCNA and DEG sets. They were validated as active transcripts and showed diagnostic values for DM and IPF. However, ssGSEA revealed distinct infiltration patterns in DM and IPF. These four genes all showed a positive correlation with immune cells abundance in DM, but not in IPF. Finally, we identified one possible key transcription factor, MYC, that interact with all four hub genes.

Conclusion

Through bioinformatics analysis, we identified common hub genes and shared molecular pathways underlying DM and IPF, which provides valuable insights into the intricate mechanisms of these diseases and offers potential targets for diagnostic and therapeutic interventions.

IFN-γ: An overlooked cytokine in dermatomyositis with anti-MDA5 antibodies

Dermatomyositis with anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5 DM) is a rare autoimmune disease, often complicated by life-threatening, rapidly progressive interstitial lung disease. Additional manifestations of the disease include skin lesions, vascular abnormalities, joints and muscles pain. Despite its clinical significance, the pathogenesis of anti-MDA5 DM remains largely unknown. Currently, the disease is perceived as driven by type I interferon (IFN) whose expression is increased in most of the patients. Importantly, the regulation of IFN-γ is also altered in anti-MDA5 DM as evidenced by the presence of IFN-γ positive histiocytes in the lungs of patients, and the identification of autoantibodies that directly stimulate the production of IFN-γ by mononuclear cells. This review critically examines the pathogenesis of the disease, shedding light on recent findings that emphasize a potential role of IFN-γ. A novel conceptual framework is proposed, which integrates the molecular mechanisms altering IFN-γ regulation in anti-MDA5 DM with the known functional effects of IFN-γ on key tissues affected during the disease, such as the lungs, skin, and vessels. Understanding the precise role and relevance of IFN-γ in the pathogenesis of the disease will not only enhance the selection of available therapies for anti-MDA5 DM patients but also pave the way for the development of new therapeutic approaches targeting the altered molecular pathways.

Metagenome-wide association study of gut microbiome features for myositis

PURPOSE

The clinical relevance and pathogenic role of gut microbiome in both myositis and its associated interstitial lung disease (ILD) are still unclear. The purpose of this study was to investigate the role of gut microbiome in myositis through comprehensive metagenomic-wide association studies (MWAS).

METHODS

We conducted MWAS of the myositis gut microbiome in a Chinese cohort by using whole-genome shotgun sequencing of high depth, including 30 myositis patients and 31 healthy controls (HC). Among the myositis patients, 11 developed rapidly progressive interstitial lung disease (RP-ILD) and 10 had chronic ILD (C-ILD).

RESULTS

Analysis for overall distribution level of the bacteria showed Alistipes onderdonkii, Parabacteroides distasonis and Escherichia coli were upregulated, Lachnospiraceae bacterium GAM79, Roseburia intestinalis, and Akkermansia muciniphila were downregulated in patients with myositis compared to HC. Bacteroides thetaiotaomicron, Parabacteroides distasonis and Escherichia coli were upregulated, Bacteroides A1C1 and Bacteroides xylanisolvens were downregulated in RP-ILD cases compared with C-ILD cases. A variety of biological pathways related to metabolism were enriched in the myositis and HC, RP-ILD and C-ILD comparison. And in the analyses for microbial contribution in metagenomic biological pathways, we have found that E. coli played an important role in the pathway expression in both myositis group and myositis-associated RP-ILD group. Anti-PL-12 antibody, anti-Ro-52 antibody, and anti-EJ antibody were found to have positive correlation with bacterial diversity (Shannon-wiener diversity index and Chao1, richness estimator) between myositis group and control groups. The combination of E. coli and R. intestinalis could distinguish myositis group from HC effectively. R. intestinalis can also be applied in the distinguishment of RP-ILD group vs. C-ILD group in myositis patients.

CONCLUSION

Our MWAS study first revealed the link between gut microbiome and pathgenesis of myositis, which may help us understand the role of gut microbiome in the etiology of myositis and myositis-associated RP-ILD.

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.

Cyclophosphamide-induced liver injury during treatment of interstitial lung disease in juvenile dermatomyositis

A middle-childhood aged girl with recently diagnosed MDA5+ juvenile dermatomyositis complicated by interstitial lung disease presented with diffuse abdominal pain and scleral icterus following the initiation of cyclophosphamide therapy. A laboratory workup revealed elevated liver enzymes and hyperbilirubinaemia. She was admitted for worsening liver function, and all medications were held with concern for drug-induced liver injury. A workup for infectious and autoimmune causes of transaminitis was negative. A liver biopsy revealed diffuse apoptotic cells without evidence of portal obstruction. A diagnosis of cyclophosphamide-induced liver injury was made. She was initiated on intravenous methylprednisolone with a steroid taper, leading to recovery. Cyclophosphamide was replaced by tofacitinib and abatacept for control of interstitial lung disease, which was well tolerated. Although cyclophosphamide in high doses may cause sinusoidal obstruction syndrome, hepatocellular liver injury is rare. Here to our knowledge, we present the first case report of hepatocellular injury caused by intravenous cyclophosphamide in a paediatric patient with a rheumatic condition.

Changes in anti-MDA5 antibody titres and serum cytokine levels before and after diagnosis of anti-MDA5 antibody-positive dermatomyositis

OBJECTIVES

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive DM is characterized by rapidly progressive interstitial lung disease and has a poor prognosis. We aimed to investigate whether anti-MDA5 antibody titres and cytokine levels predict clinical course, and evaluate changes in both parameters before and after diagnosis.

METHODS

This was a retrospective, single-centre study in 38 patients with anti-MDA5 antibody-positive DM. We compared clinical characteristics and laboratory data at diagnosis between patients in the treatment response (n = 23) and non-response (n = 15) groups, and between those in the relapse (n = 5) and non-relapse (n = 24) groups. We also measured serum anti-MDA5 antibody titres and cytokine levels before and after diagnosis.

RESULTS

The non-response group was older, had a higher ground-glass opacity score, lower PaO2/FiO2, higher CRP level, and higher anti-MDA5 antibody titre than the response group. No cytokines significantly differed between groups at diagnosis. The relapse group had a significantly higher anti-MDA5 antibody titre than the non-relapse group. In the survivor group, the anti-MDA5 antibody titre and levels of IFN-α, IFN-γ, monocyte chemotactic protein-1 (MCP-1), IL-6, IL-33, CRP, and ferritin were significantly lower 6 months post-treatment than at diagnosis. Macrophage-associated cytokines such as IL-6, IL-8, IL-18 and MCP-1 increased after anti-MDA5 antibody positivity in three patients who were anti-MDA5 antibody-positive before diagnosis.

CONCLUSION

The anti-MDA5 antibody titre at diagnosis may predict the clinical course. Levels of macrophage-associated cytokines significantly declined at 6 months post-treatment, and they may have increased after anti-MDA5 antibody titre positivity.

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.

Clinical features and prognostic factors of anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis with rapidly progressive interstitial lung disease in Chinese patients

OBJECTIVE

The objective of this study is to investigate clinical features and prognostic factors of antimelanoma differentiation-associated gene 5 (anti-MDA5)-positive dermatomyositis with rapidly progressive interstitial lung disease (RP-ILD) in Chinese patients.

METHODS

Clinical features and prognostic factors of patients with newly diagnosed or recurrent dermatomyositis patients were retrospectively analyzed. All patients were divided into the anti-MDA5-positive or negative dermatomyositis, and with or without RP-ILD groups. Clinical features and prognostic factors were statistically compared among different groups.

RESULTS

The serum ferritin (SF) levels (1500.0 [658.80, 1844.0]) and γ-glutamyl transpeptidase (γ-GT) (125.5 [61.0, 232.0] vs. 28 [16.0, 41.0], Z = 5.528; p < .001) were markedly higher, and phosphocreatine myoenzyme (CK) (73.0 [42.0, 201.0] vs. 1333.0 [79.0, 8000.0], Z = -2.739, p = .006), serum albumin level (32.51 ± 5.23 vs. 35.81 ± 5.88, t = -2.542, p = .013), and lymphocyte count (0.80 ± 0.36 vs. 1.45 ± 0.77, t = -4.717, p < .001) were lower than those in anti-MDA5-negative counterparts. Among patients with anti-MDA5 antibody (Ab) with RP-ILD, the SF level (1531.0 [1163.8, 2016.5] vs. 584.9 [564.8, 1042.5], Z = 2.664, p = .008), γ-GT (134.0 [81.0, 204.5] vs. 123.0 [76.0, 189.0], Z = 3.136, p = .002) and positive rate of anti-RO-52 Ab (90.9% vs. 50.0%, χ²  = 7.222, p = .013) were higher and lymphocyte count (0.79 ± 0.38 vs. 1.32 ± 0.74, t = -3.025, p = .029) was lower than those in their counterparts without RP-ILD. The SF level of anti-MDA5 nonsurvivors (1544 [1447.32, 2089.0] vs. 584.9 [515.7, 1500.0], Z = 2.096, p = .030), anti-RO-52 Ab-positive rate ([16/18, 88.9%] vs. [9/16, 56.2%], χ²  = 4.636, p = .031) were higher than those in survivors. Lymphocytopenia was a risk factor for RP-ILD and death of patients with anti-MDA5-positive dermatomyositis. The area under receiver operating characteristic curve was 0.888 (95% confidence interval: 0.756, 1.000; p < .001), the sensitivity was 85.7%, the specificity was 93.8%, and Youden's index was 0.795.

CONCLUSIONS

Anti-MDA5-positive dermatomyositis patients are prone to developing RP-ILD. Declined lymphocyte count is a critical risk factor for RP-ILD, probably acting as a simple and effective predictor for Chinese patients with anti-MDA5-positive dermatomyositis.

Vitamin A Promotes the Fusion of Autophagolysosomes and Prevents Excessive Inflammasome Activation in Dextran Sulfate Sodium-Induced Colitis

Vitamin A ensures intestinal homeostasis, impacting acquired immunity and epithelial barrier function; however, its role in innate immunity is mostly unknown. Here, we studied the impact of vitamin A in different dextran sulfate sodium (DSS)-induced colitis animal models. Interestingly, more severe DSS-induced colitis was observed in vitamin A-deficient (VAD) mice than in vitamin A-sufficient (VAS) mice; the same was observed in VAD severe combined immunodeficient mice lacking T/B cells. Remarkably, IL-1β production, LC3B-II expression, and inflammasome activity in the lamina propria were significantly elevated in VAD mice. Electron microscopy revealed numerous swollen mitochondria with severely disrupted cristae. In vitro, non-canonical inflammasome signaling-induced pyroptosis, LC3B-II and p62 expression, and mitochondrial superoxide levels were increased in murine macrophages (RAW 264.7) pretreated with retinoic acid receptor antagonist (Ro41-5253). These findings suggest that vitamin A plays a crucial role in the efficient fusion of autophagosomes with lysosomes in colitis.

Anti-MDA-5 Antibody-positive Dermatomyositis after Allogeneic Bone Marrow Transplantation for Acute Transformation of Chronic Myelogenous Leukemia

Anti-melanoma differentiation-associated gene 5 (MDA-5) antibody-positive dermatomyositis is a disease with a poor prognosis associated with rapid progressive interstitial pneumonia. Autoimmune diseases have occasionally been reported to occur after hematopoietic stem cell transplantation (HSCT). We experienced a case of anti-MDA-5 antibody-positive dermatomyositis after HSCT. In this case, a sufficient dose of cyclophosphamide could not be administered due to an impaired bone marrow function. We discuss the complications of autoimmune diseases after HSCT.

Decrease in cell counts and alteration of phenotype characterize peripheral NK cells of patients with anti-MDA5-positive dermatomyositis

OBJECTIVE

To investigate the levels and phenotypes of peripheral natural killer (NK) cells in anti-MDA5+ dermatomyositis (DM) patients, and their association with clinical features.

METHODS

Peripheral NK cell counts (NKCCs) were retrospectively collected from 497 patients with idiopathic inflammatory myopathies and 60 healthy controls. Multi-color flow cytometry was used to determine the NK cell phenotype in additional 48 DM patients and 26 healthy controls. The association of NKCC and NK cell phenotypes with the clinical features and prognosis were analyzed in anti-MDA5+ DM patients.

RESULTS

NKCC was significantly lower in anti-MDA5+ DM patients than in those with other IIM subtypes and healthy controls. A significant decrease in NKCC was associated with disease activity. Furthermore, NKCC < 27 cells/μL was an independent risk factor for 6-month mortality in anti-MDA5+ DM patients. In addition, identification of the functional phenotype of NK cells revealed significantly increased expression of the inhibitory marker CD39 in CD56^brightCD16^dimNK cells of anti-MDA5+ DM patients. CD39⁺NK cells of anti-MDA5+ DM patients showed increased expression of NKG2A, NKG2D, Ki-67, decreased expression of Tim-3, LAG-3, CD25, CD107a, and reduced TNF-α production.

CONCLUSION

Decreased cell counts and inhibitory phenotype are significant characteristics of peripheral NK cells in anti-MDA5+ DM patients.

Peripheral lymphocyte count defines the clinical phenotypes and prognosis in patients with anti-MDA5-positive dermatomyositis

OBJECTIVE

To explore the role of peripheral lymphocyte count in phenotyping and prognosis prediction in dermatomyositis (DM) patients with anti-MDA5 antibodies.

METHODS

In total, 1669 patients with idiopathic inflammatory myopathy (IIM) were retrospectively enrolled. Clinical characteristics and prognosis of patients with anti-MDA5+ DM were analyzed in association with peripheral lymphocyte counts and clusters determined by unsupervised machine learning.

RESULTS

The peripheral lymphocyte count was significantly lower in the anti-MDA5+ DM group (N = 421) than in the other IIM serotype groups. The anti-MDA5+ DM patients were divided into three groups; the severe lymphopenia group had skin ulcers and rapidly progressive interstitial lung disease (RP-ILD); patients with a normal lymphocyte count had a younger age of onset, more frequent arthritis, and normal serum ferritin levels, whereas mild lymphopenia group showed a moderate increase of serum ferritin and intermediate incidence of RP-ILD. Survival analysis revealed that the 3- and 6-month mortality rates were significantly higher in the severe lymphopenia group (29.0% and 42.1%, respectively) than in the mild lymphopenia group and normal lymphocyte count group (p value <0.001). Consistently, unsupervised machine learning identified three similar groups; the arthritis cluster shows the highest lymphocyte counts and best prognosis; the RP-ILD cluster presents the lowest peripheral lymphocyte, high incidence of RP-ILD, and poor prognosis; the typical DM rash cluster had a moderate peripheral lymphocyte count and an intermediate prognosis.

CONCLUSIONS

Lymphopenia is a unique manifestation of anti-MDA5+ DM. Peripheral lymphocyte count can define clinical phenotypes and predict prognosis in anti-MDA5+ DM.

Type I interferon score is associated with the severity and poor prognosis in anti-MDA5 antibody-positive dermatomyositis patients

Objectives

To investigate the clinical significance of the interferon (IFN) score, especially the IFN-I score, in patients with anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis (anti-MDA5+ DM).

Methods

We enrolled 262 patients with different autoimmune diseases, including idiopathic inflammatory myopathy, systemic lupus erythematosus, rheumatoid arthritis, adult-onset Still’s disease, and Sjögren’s syndrome, as well as 58 healthy controls. Multiplex quantitative real-time polymerase chain reaction (RT-qPCR) using four TaqMan probes was used to evaluate type I IFN-stimulated genes (IFI44 and MX1), one type II IFN-stimulated gene (IRF1), and one internal control gene (HRPT1), which were used to determine the IFN-I score. The clinical features and disease activity index were compared between the high and low IFN-I score groups in 61 patients with anti-MDA5+ DM. The associations between laboratory findings and the predictive value of the baseline IFN-I score for mortality were analyzed.

Results

The IFN score was significantly higher in patients with anti-MDA5+ DM than in healthy controls. The IFN-I score was positively correlated with the serum IFN-α concentration, ferritin concentration, and Myositis Disease Activity Assessment Visual Analogue Scale (MYOACT) score. Compared with patients with a low IFN-I score, patients with a high IFN-I score showed a higher MYOACT score, C-reactive protein concentration, aspartate transaminase concentration, ferritin concentration, plasma cell percentage, and CD3+ T-cell percentage, as well as lower lymphocyte, natural killer cell, and monocyte counts. The 3-month survival rate was significantly lower in patients with an IFN-I score of &gt;4.9 than in those with an IFN-I score of ≤4.9 (72.9% vs. 100%, respectively; P = 0.044).

Conclusion

The IFN score, especially the IFN-I score, measured by multiplex RT-qPCR is a valuable tool to monitor disease activity and predict mortality in patients with anti-MDA5+ DM.

Analysis of the clinical features of antisynthetase syndrome: a retrospective cohort study in China

OBJECTIVE

To summarize the clinical, serological, and radiological characteristics of anti-synthetase syndrome (ASS) patients with different anti-aminoacyl-tRNA synthase antibody.

METHODS

Retrospective analysis was performed based on the clinical data of 88 patients diagnosed with ASS in Tianjin Medical University General Hospital from January 2015 to December 2020. The clinical data included general conditions, serological indexes, high-resolution CT (HRCT) characteristics, and pulmonary function manifestations.

RESULTS

Among the 88 patients, there were 17 males and 71 females. The anti-synthetase antibodies included anti-Jo-1 (n = 42), anti-PL-7 (n = 14), anti-PL-12 (n = 9), anti-EJ (n = 20), and anti-OJ (n = 3) antibodies. The most common clinical manifestations of ASS patients were interstitial lung disease (ILD) (90%, 79/88), followed by myositis (79.5%, 70/88), arthritis (50%, 44/88), and rash (50%, 44/88). The frequency of arthritis in the anti-Jo-1 antibody-positive group was higher than that of the anti-PL-7 and anti-EJ antibody groups (P = 0.004, P = 0.002, respectively). The frequency of Gottron's sign in the anti-PL-7 antibody positive group was higher than that of the anti-Jo-1 and anti-PL-12 antibody-positive groups (P = 0.006, P = 0.04). Isolated arthritis was the most frequent initial symptoms in anti-Jo-1 antibody-positive group (47.6%, 20/42), while isolated ILD was most frequent in patients with anti-EJ antibody (50%, 10/20), and isolated myositis in patients carrying anti-OJ (66.7%, 2/3). There were only 32 cases (36.4%) with the typical clinical triad (myositis, arthritis, ILD). In our cohort, 79 patients (90%) were complicated with ILD. Meanwhile, 7 out of 79 cases were classified into rapid progressive group with 6 cases (85.7%) carrying anti-Ro-52 antibody. The probability of reticular and honeycombing shadow in HRCT of patients with anti-EJ antibody positive was higher than that of other groups (P < 0.05).

CONCLUSION

ILD, myositis, and arthritis were the most common clinical manifestations in patients with ASS. Different antibody-positive patients have different initial symptoms. Patients with isolated arthritis, myositis, and ILD should be vigilant of ASS. The complication of anti-Ro-52 antibody in ASS patients was associated with rapidly progressive pulmonary interstitial disease. Patients with positive anti-EJ antibodies tend to have ILD as the first symptom, and with high occurrence of ILD, the HRCT showed more serious patterns, suggesting the correlation between anti-EJ antibodies and ILD. Key Points • Analyzing specific clinical manifestations in ASS patients with different ARS antibodies can raise awareness of the disease and reduce misdiagnosis. • Anti-EJ antibodies were correlated with ILD. • Anti-Ro-52 antibodies may correlate with RP-ILD in ASS patients.

Time-dependent changes in RPILD and mortality risk in anti-MDA5+ DM patients: a cohort study of 272 cases in China

OBJECTIVES

Anti-melanoma differentiation-associated gene 5 positive (anti-MDA5+) DM has a close relationship with rapidly progressive interstitial lung disease (RPILD) and is associated with high mortality. However, data regarding the time-dependent risk of RPILD and deaths during disease progression are limited. We conducted this study to investigate whether the risk of RPILD and death were time-dependent or not in anti-MDA5+ DM.

METHODS

We assessed a cohort of 272 patients with anti-MDA5+ DM. The clinical characteristics of patients with anti-MDA5+ were collected, and COX regression was used to analyse independent risk factors for RPILD and death. We also described changes in risk of RPILD and death over time and their potential clinical implications.

RESULTS

There were 272 anti-MDA5+ DM patients enrolled in this study. According to the multivariate cox regression analysis, short disease course, high CRP level, anti-Ro52 positive and anti-MDA5 titre (++∼+++) were independent risk factors of RPILD. High creatine kinase level, high CRP level and RPILD were independent risk factors for death, and >90% RPILD and 84% mortality occurred in the first 6 months after disease onset. Notably, the first 3 months is a particularly high-risk period, with 50% of RPILD and 46% of deaths occurring. Hazards regarding RPILD and mortality diminished over time during a median follow-up of 12 months.

CONCLUSION

These results suggest significant, time-dependent changes in RPILD and mortality risk in anti-MDA5+ DM patients, providing a cut-off time window to estimate disease progression and poor prognosis.

Elevated platelet-to-lymphocyte ratio and neutrophil-to-lymphocyte ratio in patients with polymyositis/dermatomyositis: a retrospective study

OBJECTIVES

This study aimed to examine the diagnostic and prognostic value of the platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) in patients with polymyositis/dermatomyositis (PM/DM).

METHOD

Clinical data of 200 patients with PM/DM and 204 healthy controls were retrospectively reviewed. We examined whether the PLR and NLR were associated with PM/DM.

RESULTS

The PLR and NLR were higher in patients with PM/DM than in controls (both P < 0.001). The PLR and NLR were higher in patients with DM than in those with PM (both P < 0.01). The PLR was higher in the anti-melanoma differentiation-associated protein-5 (anti-MDA5) ⁺ PM/DM group than in the anti-MDA5^- PM/DM group (P = 0.002). The NLR in non-survivors was higher than that in survivors (P = 0.01). The NLR was positively correlated with the occurrence of interstitial lung disease (ILD). The PLR and NLR were independent predictors of PM/DM, as well as risk factors (both P < 0.001). Moreover, the NLR had a predictive value for PM/DM-ILD and was closely related to mortality (P = 0.033, P = 0.003, respectively).

CONCLUSIONS

Patients with PM/DM have a higher NLR and PLR than healthy controls, especially in those with anti-MDA5⁺. The PLR and NLR are independent risk factors for PM/DM and have some predictive value. The NLR is correlated with ILD and associated with an increased risk of mortality in patients with PM/DM. The NLR and PLR may be simple, economical, and accurate diagnostic and prognostic markers for patients with PM/DM. Key points • The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) have been studied in numerous inflammatory diseases as potential markers, but their clinical significance in polymyositis/dermatomyositis (PM/DM) remains unclear. • We examined the changes in the NLR and PLR between patients with PM/DM and healthy controls, as well as their association with mortality, interstitial lung disease, and anti-melanoma differentiation-associated protein-5. • Patients with PM/DM may benefit from using the NLR and PLR as simple, economical, and accurate diagnostic and prognostic markers.

Prognosis of spontaneous pneumomediastinum occurring in dermatomyositis or polymyositis patients with interstitial lung disease according to antimelanoma differentiation-associated gene 5 antibody status: a retrospective cohort study

OBJECTIVES

Spontaneous pneumomediastinum (SPNM) historically has been considered a poor prognostic factor in dermatomyositis/polymyositis patients complicated with interstitial lung disease (ILD). However, there is a lack of actual data regarding the association between SPNM occurrence and mortality in dermatomyositis/polymyositis patients. This study aimed to assess the association between SPNM occurrence and mortality in myositis patients with ILD according to antimelanoma differentiation-associated gene 5 (MDA5) antibody status.

METHODS

Dermatomyositis/polymyositis patients with ILD who were hospitalised at five Japanese hospitals from 2016 to 2020 were included in this retrospective observational study. We collected data about baseline characteristics including myositis-specific autoantibodies, treatments, SPNM and death within 1 year from therapy initiation or strengthening. Baseline characteristics and outcomes were compared between patients with and without SPNM (the SPNM group and the non-SPNM group, respectively).

RESULTS

A total of 119 patients were analysed. SPNM occurred in 23 patients, and 15 patients died. Fifteen patients with SPNM were anti-MDA5 antibody positive. The mortality rate was significantly higher in the SPNM group (34.8%) than in the non-SPNM group (7.3%) (p=0.001). All deaths in the SPNM group occurred in anti-MDA5 antibody-positive patients (8/15), whereas none of the anti-MDA5 antibody-negative patients in the SPNM group died (0/8). In anti-MDA5 antibody-positive patients, the mortality rate was significantly higher in patients with SPNM occurrence (53.3%) than in those without SPNM occurrence (4.0%) (p=0.001).

CONCLUSION

SPNM occurred more frequently in anti-MDA5 antibody-positive than in anti-MDA5 antibody-negative myositis patients. SPNM occurrence was associated with higher mortality risk, especially in anti-MDA5 antibody-positive patients.

Clinical parameters of therapeutic apheresis induction in clinically amyopathic dermatomyositis patients with rapid progressive interstitial lung disease

INTRODUCTION

The purpose of this study is to clarify the clinical parameters of therapeutic apheresis (TA) induction in clinically amyopathic dermatomyositis patients with rapid progressive interstitial lung disease.

METHODS

Literature publications prior to November 2021 from PubMed and Ichushi-Web were used. We collected details of TA and clinical features. The data were divided into two groups determined by the outcome, survived and deceased. Then, we estimated clinical parameters between them.

RESULTS

There were 151 cases, 134 of which had reported outcomes and 64 of which were positive for the anti-MDA5 antibody. Eighty patients survived. Forty-eight patients were treated with plasma exchange and 34 with polymyxin-B immobilized fibers direct hemoperfusion. Regarding clinical parameters, only the PaO2 to FiO2 (P/F) ratio was useful. The cut-off point of the P/F ratio was 174 on the ROC curve.

CONCLUSION

The parameter for induction is considered when the P/F ratio is lower than 200.

Anti-MDA5 antibody dermatomyositis-associated rapidly progressive interstitial lung disease patient complicated with mixed connective tissue disease: A case report

Anti-MDA5 antibody dermatomyositis (DM) is a special type of myositis, which can potentially cause rapidly progressive interstitial lung disease (RP-ILD). Mixed connective tissue disease (MCTD) is a complex disease with different characteristics of autoimmune connective tissue disease, associated with ILD. Both are rare diseases, and few patients with both diseases have been reported. A 71-year-old woman complained of palpitations, with a 2 months history of rash around her hands, extensor surface of right elbow, and the nape of her neck. Subsequently, the patient had acute exacerbation of dyspnea and tachypnea. Anti-Ro52, U1 RNP and MDA5 antibodies were positive; the presenting evidence was suggestive of anti-MDA5⁺ DM-RP-ILD complicated with MCTD. Our patient deteriorated rapidly and had a fatal outcome, despite "triple therapy" for RP-ILD. This case illustrates that patients with coexisting anti-MDA5⁺ DM and MCTD have the former's typical clinical manifestations, and may develop ILD quickly rather than slowly as in MCTD, especially with the coexistence of anti-Ro52 antibodies.

Machine learning for screening and predicting the risk of anti-MDA5 antibody in juvenile dermatomyositis children

Objective

The anti-MDA5 (anti-melanoma differentiation associated gene 5) antibody is often associated with a poor prognosis in juvenile dermatomyositis (JDM) patients. In many developing countries, there is limited ability to access myositis- specific antibodies due to financial and technological issues, especially in remote regions. This study was performed to develop a prediction model for screening anti-MDA5 antibodies in JDM patients with commonly available clinical findings.

Methods

A cross-sectional study was undertaken with 152 patients enrolled from the inpatient wards of Beijing Children's Hospital between June 2018 and September 2021. Stepwise logistic regression, least absolute shrinkage and selection operator (LASSO) regression, and the random forest (RF) method were used to fit the model. Model discrimination, calibration, and decision curve analysis were performed for validation.

Results

The final prediction model included eight clinical variables (gender, fever, alopecia, periungual telangiectasia, digital ulcer, interstitial lung disease, arthritis/arthralgia, and Gottron sign) and four auxiliary results (WBC, CK, CKMB, and ALB). An anti-MDA5 antibody risk probability-predictive nomogram was established with an AUC of 0.975 predicted by the random forest algorithm. The model was internally validated by Harrell's concordance index (0.904), the Brier score (0.052), and a 500 bootstrapped satisfactory calibration curve. According to the net benefit and predicted probability thresholds of decision curve analysis, the established model showed a significantly higher net benefit than the traditional logistic regression model.

Conclusion

We developed a prediction model using routine clinical assessments to screen for JDM patients likely to be anti-MDA5 positive. This new tool may effectively predict the detection of anti-MDA5 in these patients using a non-invasive and efficient way.

Differences in the Clinical Characteristics and 1-Year Mortality Rates of Patients with Dermatomyositis with anti-Jo-1 and anti-MDA5 Antibodies

Objective

Patients with anti-Jo-1 antibodies (Abs) and anti-melanoma differentiation-associated protein 5 (MDA5) Abs are at a higher risk of interstitial lung disease (ILD) and have a mortality rate higher than that of patients with anti-Jo-1 Abs. This study investigated differences in the clinical characteristics and prognosis of patients with anti-Jo-1 Abs and anti-MDA5 Abs with dermatomyositis (DM).

Methods

We retrospectively reviewed the medical records of 38 patients with DM from January 2000 to December 2021. The patients were divided into anti-Jo-1 Abs and anti-MDA5 Abs groups. The basic demographic data, clinical manifestations, and 1-year mortality rates of the groups were compared.

Results

Among the 38 patients, 30 were anti-Jo-1-Abs positive and 8 patients were anti-MDA5 Aba positive. The patients with anti-MDA5 Abs presented with more apparent cutaneous symptoms and aggressive pulmonary manifestations than did those with anti-Jo-1 Abs. The mortality rate in the anti-MDA5 Abs group (1.95/person-year (PY)) was much higher than that in anti-Jo-1 Abs group (0.094/PY), and most of the mortalities occurred within the first 1-3 months of follow-up.

Conclusion

Distinct cutaneous and pulmonary manifestations were observed in the anti-Jo-1 Abs and anti-MDA5 Abs groups. The mortality rate in the anti-MDA5 Abs group was significantly higher than that in the anti-Jo-1 Abs group. Early recognition is crucial to ensuring higher chances of survival for patients with anti-MDA5 Abs.

Four cases of dermatomyositis with abnormally high anti-MDA-5 antibody titres and not high levels of serum ferritin

Anti-melanoma differentiation-associated gene 5 (MDA-5) antibody-positive dermatomyositis is a fatal disease presenting with rapidly progressive interstitial lung disease. High ferritin levels are a well-known poor prognostic factor. A high anti-MDA-5 antibody titre was also recently identified as a poor prognostic factor. We encountered four cases that had extremely high anti-MDA-5 antibody titres without high levels of ferritin in the initial examination. All cases were female with ages ranging between 29 and 54 years (mean age, 44 years). In the initial examination, anti-MDA-5 antibody titres were 2060-3040 (normal range, <32 index), ferritin levels were 87-480 ng/ml (normal range, 2.6-129.4 ng/ml), KL-6 level was 186-1806 U/ml (normal range, <500 U/ml), and creatine kinase level was normal in all patients. One patient had respiratory distress on exertion. Computed Tomography (CT) images showed mild ground-glass attenuation/reticular shadows near the pleura in all patients. Three patients were treated with a combination of high-dose glucocorticoids, intermittent intravenous cyclophosphamide, and calcineurin inhibitors, and two required plasma exchange due to the worsening of lung lesion. In these patients, ferritin and KL-6 levels tended to elevate after the beginning of treatment. Very mild pulmonary lesions disappeared in one patient treated with moderate doses of a glucocorticoid and calcineurin inhibitor. All patients survived, and one required oxygen on exertion at discharge. The condition of patients with abnormally high anti-MDA-5 antibody titres may deteriorate even though ferritin levels were not high and lung shadows are minimal at presentation. Therefore, intensive treatment needs to be considered early in the course of the disease regardless of the serum ferritin level.

Successful Rescue Therapy With Daratumumab in Rapidly Progressive Interstitial Lung Disease Caused by MDA5-Positive Dermatomyositis

Melanoma differentiation-associated gene 5 (MDA5) positive dermatomyositis is a rare systemic autoimmune disease that is associated with life-threatening rapidly progressive interstitial lung disease. We report the case of a 19-year-old male patient with a life-threatening disease course caused by rapidly progressive interstitial lung disease that caused respiratory failure despite intensive immunosuppression with multiple agents (steroids, IV immunoglobulins, tofacitinib, cyclophosphamide, mycophenolate mofetil, ciclosporin and rituximab). Rescue therapy with daratumumab, an anti-CD38-antibody, was initiated. Significant pulmonary improvement was noticed after 4 weekly injections of 1,800 mg. After 6 months of follow up, stable disease remission with significant pulmonary improvement and persistent depletion of CD38+ plasma cells and MDA5-antibody titers were seen. This is the first report of the successful use of daratumumab in dermatomyositis. It highlights the potential of CD38 targeted therapies for severe antibody-mediated autoimmune diseases such as dermatomyositis.

Evaluation and validation of the prognostic value of anti-MDA5 IgG subclasses in dermatomyositis-associated interstitial lung disease

OBJECTIVE

To investigate the association between the anti-melanoma differentiation associated gene 5 (MDA5) IgG subclasses and prognosis of patients with dermatomyositis (DM)-associated interstitial lung disease (ILD).

METHODS

This retrospective study included 122 anti-MDA5 positive DM-ILD patients admitted from October 2017 to October 2020 as training cohort, and additional 68 patients from August 2014 to September 2017 as validation cohort. The levels of anti-MDA5 total IgG and IgG subclasses were measured using in-house enzyme-linked immunosorbent assays, and analysed in association with the patient prognosis.

RESULTS

In the training cohort, the concentrations of anti-MDA5 IgG1 and IgG3 in non-survivors were significantly higher than in survivors (P < 0.05), whereas there were no significant differences in the IgG2 and IgG4 levels. Kaplan-Meier survival analysis revealed that the levels of anti-MDA5 total IgG, IgG1 and IgG3 were associated with mortality (P < 0.05). Multivariate analysis revealed anti-MDA5 IgG1 >13 U/ml and anti-MDA5 IgG3 >11 U/ml were independent risk factors for death of DM-ILD patients (P < 0.05). Anti-MDA5 IgG1 was confirmed as an independent risk factor in the validation cohort, while anti-MDA5 IgG3 was not. Anti-MDA5 IgG1 showed greater discriminable power for patient prognosis (Youden index 0.494) than anti-MDA5 total IgG, IgG3, or the combination of IgG1 and IgG3 (Youden index 0.356, 0.32 and 0.447, respectively).

CONCLUSION

Anti-MDA5 IgG1 and IgG3 are significantly associated with poor prognosis in DM-ILD patients, and anti-MDA5 IgG1 is more efficient as a prognostic biomarker in DM-ILD patients.