Antimelanoma differentiation-associated protein 5 antibody level is a novel tool for monitoring disease activity in rapidly progressive interstitial lung disease with dermatomyositis

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.

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.

A case of autoimmune pulmonary alveolar proteinosis during the course of treatment of rapidly progressive interstitial pneumonia associated with anti-MDA5 antibody-positive dermatomyositis

BACKGROUND

Autoimmune pulmonary alveolar proteinosis (APAP) is a diffuse lung disease that causes abnormal accumulation of lipoproteins in the alveoli; however, its pathogenesis remains unclear. Recently, APAP cases have been reported during the course of dermatomyositis. The combination of these two diseases may be coincidental; however, it may have been overlooked because differentiating APAP from a flare-up of interstitial pneumonia associated with dermatomyositis is challenging. This didactic case demonstrates the need for early APAP scrutiny.

CASE PRESENTATION

A 50-year-old woman was diagnosed with anti-melanoma differentiation-associated gene 5 (anti-MDA5) antibody-positive dermatitis and interstitial pneumonia in April 2021. The patient was treated with corticosteroids, tacrolimus, and cyclophosphamide pulse therapy for interstitial pneumonia complicated by MDA5 antibody-positive dermatitis, which improved the symptoms and interstitial pneumonia. Eight months after the start of treatment, a new interstitial shadow appeared that worsened. Therefore, three additional courses of cyclophosphamide pulse therapy were administered; however, the respiratory symptoms and interstitial shadows did not improve. Respiratory failure progressed, and 14 months after treatment initiation, bronchoscopy revealed turbid alveolar lavage fluid, numerous foamy macrophages, and numerous periodic acid-Schiff-positive unstructured materials. Blood test results revealed high anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) antibody levels, leading to a diagnosis of APAP. The patient underwent whole-lung lavage, and the respiratory disturbance promptly improved. Anti-GM-CSF antibodies were measured from the cryopreserved serum samples collected at the time of diagnosis of anti-MDA5 antibody-positive dermatitis, and 10 months later, both values were significantly higher than normal.

CONCLUSIONS

This is the first report of anti-MDA5 antibody-positive dermatomyositis complicated by interstitial pneumonia with APAP, which may develop during immunosuppressive therapy and be misdiagnosed as a re-exacerbation of interstitial pneumonia. In anti-MDA5 antibody-positive dermatomyositis, APAP comorbidity may have been overlooked, and early evaluation with bronchoalveolar lavage fluid and anti-GM-CSF antibody measurements should be considered, keeping the development of APAP in mind.

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.

Early Initiation of Plasma Exchange Therapy for Anti-MDA5+Dermatomyositis with Refractory Rapidly Progressive Interstitial Lung Disease

Objectives Dermatomyositis (DM) is often associated with fatal anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive rapidly progressive interstitial lung disease (RP-ILD). RP-ILD often fails to respond to intensive treatment and has a poor prognosis. We examined the effectiveness of early plasma exchange therapy plus intensive treatment with high-dose corticosteroids and multiple immunosuppressants. Methods Autoantibodies were identified by an immunoprecipitation assay and enzyme-linked immunosorbent assay. All clinical and immunological data were collected retrospectively from medical charts. We divided patients into two groups based on treatment regimen: intensive immunosuppressive therapy alone as initial treatment (IS group) and early initiation of plasma exchange (PE) plus intensive immunosuppressive therapy (ePE group). Early PE therapy was designated if PE therapy was initiated within two weeks of starting treatment. Comparisons of the treatment response and prognosis between groups were performed. Patients Anti-MDA5-positive DM with RP-ILD was screened. Results Forty-four RP-ILD and DM patients had anti-MDA5 antibodies. Four patients were excluded because they died before receiving sufficient combined immunosuppressive therapy or before the evaluation of the immunosuppressive treatment effectiveness (IS, n=31; ePE, n=9). All 9 patients in the ePE group had improved respiratory symptoms and were alive, whereas 12 of 31 patients in the IS group died (100 vs. 61%, p=0.037). Of the 8 patients who had 2 values for a poor prognosis, indicating the highest risk for death using the MCK model, 3 of 3 patients in the ePE group and 2 of 5 in the IS group were alive (100 vs. 40%, p=0.20). Conclusion The early initiation of ePE therapy plus intensive immunosuppressive therapy was effective for patients with DM and refractory RP-ILD.

A Case of Dermatomyositis with Coexistence of Positive Anti-MDA5 Antibodies and Anti-SSA/RO52 Antibodies, Combined with Necrotic Skin Ulcers

Background

Dermatomyositis (DM) is an idiopathic inflammatory myopathy that is clinically challenging to diagnose and has a poor prognosis. It is characterized by symmetric proximal muscle weakness, muscle tenderness, dysphagia, characteristic skin rash (heliotrope rash, Gottron's sign), elevated muscle enzyme levels, abnormal electromyography, and muscle biopsy findings. DM with positive anti-MDA5 antibodies is mainly characterized by Gottron's sign, skin ulcers, facial erythema, mechanic's hands, and V-sign. In this case, the patient presented with the rare manifestation of severe necrotic skin ulcers in association with Gottron's sign, prompting us to report this case.

Case Presentation

A 45-year-old female was admitted to the hospital with systemic joint pain, fatigue, multiple ulcers, and purulent discharge on both hands. Her myositis-specific antibody profile revealed positive anti-MDA5 and anti-SSA/RO52 antibodies. Treatment included a combination of glucocorticoids, immunosuppressants, gastric and liver protection, infection control, and wound care. After two weeks of treatment, the patient showed improvement in symptoms. However, on the 24th day of hospitalization, the wound at the right elbow joint ruptured and became infected, requiring debridement and skin grafting in the appropriate department.

Conclusion

There has been limited research and reported cases of dermatomyositis with coexistence of positive anti-MDA5 and anti-SSA/RO52 antibodies combined with severe skin ulcers. Therefore, we present this rare case and emphasize the need for close follow-up on pulmonary involvement and skin ulcer progression, as well as timely implementation of new treatment strategies to actively improve the prognosis.

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.

Transcriptomic profiling and longitudinal study reveal the relationship of anti-MDA5 titer and type I IFN signature in MDA5+ dermatomyositis

Objective

This study aimed to investigate the relationship between anti-MDA5 titer and type I IFN signature in patients with MDA5+ DM.

Methods

We explored the transcriptome profiling of PBMCs in MDA5+ DM patients with high-titer of antibody at disease onset or relapse and normal low-titer after treatment and healthy donors. Subsequently, we revealed the dynamic relationship between serum type I IFN scores and antibody titers.

Result

Differentially expressed genes in MDA5+ DM patients were enriched for related pathways and biological functions linked to viruses and cytokines compared to healthy donors. Similar differences remained pooled between the high-titer and low-titer group, and type I-specific interferon response genes showed upregulation in high-titer group. Significant correlations were found between anti-MDA5 titers and type I IFN scores (r = 0.50, P< 0.001). Contemporaneous anti-MDA5 titers revealed to be significantly higher in the group with ultra-high type I IFN scores (vs. high group, P = 0.027; vs. low group, P< 0.001). Longitudinal assessment of type I IFN scores and anti-MDA5 titers, including pre- and post-treatment changes at initial diagnosis and dynamic changes during treatment, presented an asynchrony between the two parameters in response to treatment.

Conclusion

Anti-MDA5 antibody titers correlated with type I IFN signature in patients with MDA5+ DM and they both changed dynamically but not synchronously over the course of treatment.

Age distribution and prevalence in different age groups of four myositis-specific autoantibodies, including anti-ARS, anti-MDA5, anti-Mi-2, and anti-TIF1γ antibodies

We accumulated the demographic information and analyzed the prevalence of myositis-specific antibodies (MSAs) in a large cohort across Japan as standard testing for MSAs becomes more widely available. This retrospective, observational, cohort study analyzed the records of individuals aged 0-99 years who are tested for serum MSAs at SRL Incorporation from January 2014 to April 2020 across Japan. An enzyme-linked immunosorbent assay testing was applied to determine the presence of anti-aminoacyl tRNA synthetase (anti-ARS), anti-Mi-2, anti-melanoma differentiation-associated gene 5 (anti-MDA5), or anti-transcriptional intermediary factor 1-γ (anti-TIF1γ) (Medical and Biological Laboratories). Anti-TIF1γ antibody was detected more in male patients than female patients. In contrast, women were predominant in patients with other MSAs. More than half of the anti-ARS or anti-TIF1γ antibody-positive patients were over 60 years old, although anti-MDA5 or anti-Mi-2-positive patients were mostly under <60 years old. Anti-MDA5 antibody-positive patients were mostly aged 40-59 years, while other MSA groups were mostly 60-79 years. Anti-MDA5 antibody was detected most frequently in the age range of 0-29 years. Anti-TIF1γ antibody was the second most commonly detected autoantibody in the age range of 0-19 years. Anti-ARS antibody was the most frequently detected autoantibody after the age of 30 years, and the frequency of anti-ARS gradually increased at more advanced ages. The second and third most detected autoantibodies were anti-MDA5 and anti-TIF1γ, respectively, in ages 30-79 years. We performed a nationwide >3-year evaluation of MSA detection in a routine diagnostic setting. This paper provides clinical images concerning the relationship between four MSA types and the distribution of sex and age in a large population.

The prevalence and effects of treatments of rapidly progressive interstitial lung disease of dermatomyositis/polymyositis adults: A systematic review and meta-analysis

Rapidly progressive interstitial lung disease (RP-ILD) clearly harms the prognoses of dermatomyositis/polymyositis (DM/PM) patients, however there is a dearth of numerical prevalence and therapy comparison in this field. Therefore, the purpose of this study was to determine the prevalence of RP-ILD in DM/PM patients and compare prognoses, including remission rate and survival data, between treatments. Studies with reports of RP-ILD in DM/PM patients and studies with definite remission and/or survival data of DM/PM-RP-ILD were included in the study. Data sources were Pubmed, Embase, and Cochrane Library without language restrictions. Two authors (WHL and WWQ) extracted independently the data. Estimates of the pooled effects were calculated using the Mantel-Haenszel technique (random effects). The prevalence meta-analysis included 18 papers with 6058 DM/PM patients, and 31 papers were analyzed for treatment effects, including remission rate, 6-month survival rate, 1-year survival rate, and 5-year survival rate. Database search yielded 1816 articles. In the DM/PM population, the combined prevalence of RP-ILD was 8.9% (95% CI, 5.8% to 12.1%). Patients with RP-ILD have a remission rate of 58.4% (95% CI, 47.3% to 69.4%), with biologic treatment with the highest remission rate, followed by triple therapy (defined as adding a third intravenous medication, including cyclophosphamide and immunoglobulin). Biologics therapy had the highest overall survival rate at six months (95% CI, 49.8% to 73.9%), followed by cDMARDs, plasma exchange, and triple therapy. The 1-year survival rate was 77.4% (95% CI, 66.7% to 88.1%), and triple therapy and cDMARDs had the best survival rates. The 5-year survival rate was 40.0% (95% CI, 10.0% to 69.9%). The prevalence of RP-ILD in DM/PM was approximately 8.9%, with a poor long-term prognosis. The use of biological agents appears to provide the best therapeutic outcomes, providing RP-ILD management with a novel evidence-based therapy. The use of strong immunosuppressive treatments may result in life-threatening side effects, thus clinicians must closely monitor the condition.

Mortality risk in patients with anti-MDA5 dermatomyositis is related to rapidly progressive interstitial lung disease and anti-Ro52 antibody

BACKGROUND

This study aimed to describe the clinical characteristics and analyze the poor prognostic factors in patients with anti-MDA5 dermatomyositis.

METHODS

A total of 126 adults with anti-MDA5 dermatomyositis were enrolled in this retrospective study. Information on survival time, cause of death, and baseline characteristics was collected. Patients were divided into two groups: a survival group and a non-survival group. Items with clinical significance that showed significant differences between the two groups were screened by Kaplan-Meier and Cox regression analyses to identify the predictors of poor survival.

RESULTS

Thirty-two patients were included in the non-survival group, most of whom died from respiratory failure, with pulmonary infection accounting for half. Epstein-Barr virus infection was relatively common in both groups. Aspartate transaminase, lactate dehydrogenase, and ferritin levels; erythrocyte sedimentation rate; and anti-Ro52 antibody levels were significantly higher, while the lymphocyte count was lower in the non-survival group compared with the survival group. Notably, patients in the non-survival group were more likely to present with rapidly progressive interstitial lung disease than those in the survival group. Kaplan-Meier and Cox multivariate regression analyses revealed that the prevalence of rapidly progressive interstitial lung disease, levels of anti-Ro52 antibody, and age > 57 years were important prognostic factors independent of multiple clinical parameters.

CONCLUSIONS

Rapidly progressive interstitial lung disease, anti-Ro52 antibody levels, and age > 57 years are possible predictors of mortality risk in patients with anti-MDA5 dermatomyositis.

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.

Longitudinal study of patients with antimelanoma differentiation-associated gene 5 antibody-positive dermatomyositis-associated interstitial lung disease

OBJECTIVES

To describe the 8-year longitudinal study and long-term prognosis of a large inception cohort of anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive (MDA5+) DM-interstitial lung disease (ILD) patients.

METHODS

In total, 216 patients diagnosed with MDA5+ DM-ILD were enrolled and followed up to analyse long-term survival rate. Demographic and clinical variables were collected at baseline and each temporal end point. Seventy patients who survived the first year were analysed for the long-term serological and respiratory outcomes.

RESULTS

A total of 85 patients (39.3%) died during the follow-up period up to 96 months, with 89% of the deaths occurring in the first year after diagnosis. Long-term outcome was reported in 70 patients. Serological markers including anti-MDA5 antibody showed significant improvement with time. Radiographic findings and pulmonary function also improved notably in the follow-up period, especially in rapidly progressive ILD group, as measured by high-resolution computed tomography imaging scores, the estimated forced vital capacity, estimated diffusing capacity of lung carbon monoxide and dyspnoea scores. Early application of anti-fibrosis therapy helped to improve long-term pulmonary function.

CONCLUSIONS

MDA5+ DM-ILD patients had a high mortality rate despite aggressive treatment. Patients who survived the first year usually showed a significant improvement in serological markers and pulmonary function during the long-term follow-up.

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.

Longitudinal changes in nailfold videocapillaroscopy findings differ by myositis-specific autoantibody in idiopathic inflammatory myopathy

OBJECTIVE

To assess the longitudinal changes in nailfold videocapillaroscopy (NVC) in patients expressing myositis-specific autoantibodies [anti-aminoacyl-tRNA synthetase (ARS), anti-transcriptional intermediary factor 1 (TIF1), and anti-melanoma differentiation-associated gene 5 (MDA5)].

METHODS

This study was performed retrospectively, at a single site, on an observational cohort. Seventy-one idiopathic inflammatory myopathy patients were included (25 patients expressed anti-MDA5 Abs, 24 patients expressed anti-TIF1 Abs, and 22 patients expressed anti-ARS Abs). NVC findings included giant, enlarged, and reduced capillaries, haemorrhages, capillary ramification, disorganization of the vascular array, and capillary loss. NVC findings were compared from baseline to after disease activity stabilization.

RESULTS

The frequency of enlarged capillaries at baseline was different among the three groups, and was significantly higher in patients with anti-TIF1 Abs compared with those with anti-ARS Abs (88% vs 55%, P < 0.05). Reduced capillaries were significantly increased in patients with anti-TIF1 Abs compared with those with anti-MDA5 (96% vs 44%, P < 0.0001) or anti-ARS Abs (96% vs 50%, P < 0.0005). Both enlarged and reduced capillaries improved after stabilization in patients with anti-MDA5 Abs (P < 0.0001 and P < 0.05, respectively). These improvements were not observed in patients expressing anti-TIF1 and anti-ARS Abs. However, a significant reduction in haemorrhages was observed in all three groups (P < 0.0001 for each group).

CONCLUSIONS

The results of this study demonstrate that longitudinal changes in NVC findings may vary depending on myositis-specific Ab expression. Therefore, it is crucial to assess individual NVC findings separately, as each finding may impact disease activity in a different manner.

Lung transplantation for anti-MDA5-positive dermatomyositis-associated rapid progressive interstitial lung disease: report of two cases and review of the literature

Lung transplantation is an ultimate lifesaving treatment for many patients with end-stage lung disease, whereas whether it is an optional intervention for the anti-melanoma differentiation-associated gene 5 (anti-MDA5)-positive dermatomyositis (DM)-associated rapid progressive interstitial lung disease (RP-ILD) remain controversial. We report two patients diagnosed with anti-MDA5-positive DM-associated RP-ILD, who were both bridging to lung transplant with extracorporeal membrane oxygenation (ECMO) after failing to respond to extensive immunosuppressants. The first patient received full rehabilitation, but the second patient died of DM flare at the early-stage post-lung transplantation. Most of the clinical information was parallel in these two patients except the anti-MDA5 antibody level, which gradually decreased and became negative in the first patient but always hovering in high titers in the second patient, although both of the two patients received standard immunosuppressive regimen for prevention of rejection after lung transplantation. A total of 11 patients with anti-MDA5-positive DM-associated RP-ILD who underwent lung transplantation from the literature were identified. Most patients (10/11, 90.1%) were successfully discharged and without DM flare during the follow-up period post-lung transplantation. Nine of them were followed up more than 1 year, and anti-MDA-5 antibody was reported to be negative in four patients, whereas the others were unavailable. Combined with the case series in the literature, our limited experience suggests that lung transplantation is a promising therapeutic option for end-stage patients with anti-MDA5-positive DM-associated RP-ILD, with ECMO as a bridge to lung transplantation, if necessary. However, clearance or a downtrend of anti-MDA5 antibody may be required pre-transplant to avoid DM flare and recurrent RP-ILD post-transplantation.

Coexistence of Anti-Ro52 Antibodies in Anti-MDA5 Antibody-Positive Dermatomyositis Is Highly Associated With Rapidly Progressive Interstitial Lung Disease and Mortality Risk

OBJECTIVE

Interstitial lung disease (ILD) is a common extramuscular complication contributing to significant morbidity and mortality in patients with dermatomyositis (DM) who are positive for antimelanoma differentiation-associated gene 5 antibody (anti-MDA5+). We conducted this study to investigate the association of anti-Ro52 antibodies with clinical characteristics and prognosis in patients with anti-MDA5+ DM.

METHODS

We assessed a cohort of 246 patients with anti-MDA5+ DM. To calculate hazard ratios and 95% CIs for rapidly progressive ILD (RP-ILD) and death while controlling for potential confounders, variables selected by univariate Cox regression analysis were included in a multivariate Cox regression model with the stepwise forward-selection method. A 2-tailed analysis with P < 0.05 was considered to be statistically significant.

RESULTS

A total of 246 patients with anti-MDA5+ DM were enrolled; 70 patients were male, and the patient group had an average age of 53.1 (12.4) years. Anti-Ro52 was present in 64.2% (158/246) patients. Patients with anti-MDA5+ DM who were positive for anti-Ro52 had a higher rate of RP-ILD (log-rank P < 0.001) and a higher mortality rate (log-rank P = 0.01). For patients with anti-MDA5+ DM who were positive for anti-Ro52, those with a short disease course and high inflammation were at increased risk of RP-ILD and death. The appearance of active rash was an independent protective factor of death.

CONCLUSION

Anti-Ro52 antibodies were highly prevalent in patients with anti-MDA5+ DM, and their coexistence correlated with a higher rate of RP-ILD and mortality. Patients with a short disease course, with increased inflammation, and without rash were more likely to have a poor prognosis.

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.

Cardiac involvement in anti-MDA5 dermatomyositis: a case-based review

Among myositis-specific antibodies, anti-melanoma differentiation-associated gene 5 (anti-MDA5) is one of the antibodies with a unique spectrum that is expressed principally in clinically amyopathic dermatomyositis (CADM) and, to a lesser extent, in dermatomyositis (DM). In addition to muscle and classical skin involvement, patients with anti-MDA5 DM/CADM are characterized by the expression of rapidly progressive interstitial lung diseases, vasculopathic lesions, and non-erosive arthritis. Although cardiac involvement has been described in other inflammatory myopathies, such as myocarditis, pericarditis, and conduction disorders, in anti-MDA5 DM/CADM patients, heart disease is infrequent. We report a case of a young male presenting with constitutional symptoms, polyarthritis, skin ulcers, and mild muscle weakness who developed an episode of high ventricular rate atrial fibrillation during his hospitalization. The anti-MDA5 DM diagnosis was supported by increased muscular enzymes, positive anti-MDA5 and anti-Ro52 antibodies, and the presence of organizing pneumonia. He was treated with high-dose glucocorticoids, rituximab, and beta-blocker drugs and received pharmacological cardioversion, which improved his myopathy symptoms and stabilized his heart rhythm. Here, we describe eight similar cases of anti-MDA5 DM/CADM with cardiac involvement. The case presented and the literature reviewed reveal that although rare, physicians must be aware of cardiac disease in patients with suggestive symptoms to guarantee early assessment and treatment, thereby reducing life-treating consequences.

Efficacy of plasma exchange in patients with anti-MDA5 rapidly progressive interstitial lung disease

BACKGROUND

Rapidly progressive interstitial lung disease (RP-ILD) is a frequent and severe manifestation of anti-MDA5 dermatomyositis (MDA5-DM) associated with poor outcome. The optimal treatment regimen for MDA5-DM RP-ILD is yet to be determined. Specifically, the value of adding plasma exchange (PLEX) to corticosteroids and immunosuppressants remains unclear. We aimed to evaluate the effect of PLEX on the outcome of patients with MDA5-DM RP-ILD.

METHODS

This French nationwide multicentre retrospective study included all MDA5-DM RP-ILD patients from 2012 to 2021 admitted to 18 centres. The primary endpoint was one-year transplant-free survival.

RESULTS

51 patients with MDA5-DM RP-ILD (female 67%; mean age at disease onset: 51 ± 11.6 years) were included. Thirty-two (63%) patients required mechanical ventilation and twenty-five (49%) received PLEX. One-year mortality or lung transplant occurred in 63% cases after a median follow-up of 77 [38-264] days. The Cox proportional hazards multivariable model only retained mechanical ventilation but not PLEX (p = 0.7) as independent predictor of the primary endpoint. One-year transplant-free survival rates in PLEX + vs. PLEX-were 20% vs. 54% (p = 0.01), respectively. The Kaplan-Meier estimated probabilities of one-year transplant-free survival was statistically higher in PLEX-compared to PLEX + patients (p = 0.05). PLEX + compared to PLEX-patients more frequently received mechanical ventilation and immunosuppressants suggesting PLEX + patients had a more severe disease.

CONCLUSION

MDA5-DM RP-ILD is associated with poor rate of one-year transplant-free survival. The use of PLEX was not associated with a better outcome albeit they were mainly given to more severe patients. While our study reports the largest series of MDA5-DM RP-ILD given PLEX, these results needs to be interpreted with caution owing the numerous selection, indication and interpretation bias. Further studies are needed to evaluate their efficacy in this setting.

Evaluation of the Performance of an Indirect Immunofluorescence Assay for the Detection of Anti-MDA5 Antibodies

Anti-melanoma differentiation-associated protein 5 (MDA5) antibody (Ab) positive dermatomyositis (anti-MDA5 DM) is a rare systemic autoimmune disease; further, its prognosis can be rapidly fatal due to pulmonary involvement. The identification and quantification of anti-MDA5 Abs, which serve as a highly specific biomarker of the disease, is a critical step for the establishing of both the diagnosis and monitoring of the disease's activity. The development of a simple, fast, low-cost, and specific detection system of anti-MDA5 Ab is therefore highly desirable for the purposes of routine laboratory diagnosis. Here, we developed a human cell line that stably expresses MDA5 and evaluated its analytical performance in order to detect anti-MDA5 Abs by the utilization of indirect immunofluorescence (IIF). Serum samples from 23 anti-MDA5 DM patients and 22 anti-MDA5 Abs negative myositis readings, which were obtained at time of diagnosis, were analyzed by IIF on MDA5-transfected cells. The results were compared with those obtained with specific semi-quantitative (immunodot) and quantitative (ELISA) assays. A specific cytoplasmic pattern was found solely with the sera of anti-MDA5 DM patients. The sensitivity and specificity of IIF on MDA5-transfected cells were 96% and 100%, respectively, compared with ELISA. The anti-MDA5 Abs titers that were determined by this approach were consistent with the quantitative results obtained by ELISA. Baseline concentrations of anti-MDA5 Abs, either by ELISA or IIF, were not significantly different between surviving and deceased patients; further, they did not differ significantly according to clinical phenotypes. Overall, an IIF cell-based assay constitutes a simple, fast, and low-cost approach to identify and quantify anti-MDA5 Abs; moreover, it is as efficient as ELISA.

Anti-MDA5 dermatomyositis: an update from bench to bedside

PURPOSE OF REVIEW

This review summarizes the recent developments about anti-MDA5 antibody positive dermatomyositis with a focus on its pathogenesis, clinical features and treatment options of rapidly progressive interstitial lung disease, its most ominous complication.

RECENT FINDINGS

Anti-MDA5+ dermatomyositis has a heterogeneous clinical spectrum with different patient subsets exhibiting widely different outcomes; severe acute interstitial lung disease is the main factor impacting prognosis. The pathogenetic role of anti-MDA5 antibodies is an active area of investigation.

SUMMARY

Anti-MDA5+ dermatomyositis has a wider spectrum of manifestations than previously thought. A high index of suspicion is needed not to miss atypical presentations. In the setting of acute interstitial lung involvement, once a confident diagnosis is made, an aggressive approach with early combined immunosuppression affords the best chances of survival.

Single-cell profiling reveals distinct adaptive immune hallmarks in MDA5+ dermatomyositis with therapeutic implications

Anti-melanoma differentiation-associated gene 5-positive dermatomyositis (MDA5⁺ DM) is an autoimmune condition associated with rapidly progressive interstitial lung disease and high mortality. The aetiology and pathogenesis of MDA5⁺ DM are still largely unknown. Here we describe the immune signatures of MDA5⁺ DM via single-cell RNA sequencing, flow cytometry and multiplex immunohistochemistry in peripheral B and T cells and in affected lung tissue samples from one patient. We find strong peripheral antibody-secreting cell and CD8⁺ T cell responses as cellular immune hallmarks, and over-stimulated type I interferon signaling and associated metabolic reprogramming as molecular immune signature in MDA5⁺ DM. High frequency of circulating ISG15⁺ CD8⁺ T cells at baseline predicts poor one-year survival in MDA5⁺ DM patients. In affected lungs, we find profuse immune cells infiltration, which likely contributes to the pro-fibrotic response via type I interferon production. The importance of type I interferons in MDA5⁺ DM pathology is further emphasized by our observation in a retrospective cohort of MDA5⁺ DM patients that combined calcineurin and Janus kinase inhibitor therapy show superior efficacy to calcineurin inhibitor monotherapy. In summary, this study reveals key immune-pathogenic features of MDA5⁺ DM and provides a potential basis for future tailored therapies.

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.

Rare complications of anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis: Time to nip them in the bud

Anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis (MDA5+ DM) is an infrequent autoimmune disease, which mainly distributes in Asians and females. MDA5+ DM usually presents various skin lesions and positive anti-MDA5 antibody (a myositis-specific autoantibody for itself) with amyopathic or hypomyopathic features. For MDA5+ DM patients, rapidly progressive interstitial lung disease is a common complication with a high-speed deterioration and a poor prognosis. Besides, there are other complications of MDA5+ DM patients, including pneumomediastinum, macrophage activation syndrome and spontaneous intramuscular hemorrhage. These complications were rare but lethal, so it is necessary to explore their diagnosis methods, therapies and potential mechanisms, which are helpful for early diagnoses and timely treatment. To date, several cases and studies have shown distinctive features, diagnoses and treatments of these three rare complications, and there are also some differences among them. In this review, we outlined the characteristics, administration and potential pathogenesis of these rare complications of MDA5+ DM.

The use of ELISA is comparable to immunoprecipitation in the detection of selected myositis-specific autoantibodies in a European population

Background

The reliable detection of myositis-specific autoantibodies (MSA) provides valuable clinical information regarding prognosis, clinical progression and diagnostic confirmation.

Objectives

To evaluate the reliability of a commercial ELISA immunoassay in detecting myositis-specific autoantibodies in comparison to immunoprecipitation as the reference standard.

Methods

Serum samples were chosen from a biobank of more than 3000 samples. Samples with a confirmed MSA on Immunoprecipitation (n=116) were evaluated in duplicate by ELISA to detect Mi2, MDA5, Jo1, EJ, KS, PL-7 and PL-12 (Medical &amp; Biological Laboratories Co. Ltd, Nagoya, Aichi, Japan). Healthy control samples (n=246) confirmed autoantibody negative by immunoprecipitation were similarly assessed.

Results

There was a very good agreement between ELISA and immunoprecipitation for serum samples containing anti-Mi2, MDA5, Jo1, EJ, KS and PL-7 and PL-12 auto-antibodies. Cohen’s κ values ranged from 0.86-1 for the measured autoantibodies on ELISA.

Conclusion

ELISA was an accurate method for detecting anti-synthetase, anti-Mi2 and anti-MDA5 autoantibodies.

Anti-MDA5 and anti-SSA/Ro52 antibodies double-positive dermatomyositis overlapping with rheumatoid arthritis-associated interstitial lung disease: A case report

Dermatomyositis (DM) is a poorly prognostic autoimmune disease the pathogenesis of which is multifactorial and not clearly defined. DM may be influenced by genes, environment, and immunity. The typical manifestations of DM are Gottron rash, heliotrope rash, rash on the shoulders and buttocks, erythema around fingernails, excessive keratosis of the epidermis, mechanic's hands, and interstitial lung disease (ILD), among others. Anti-melanoma differentiation-associated 5 gene (MDA5) antibody has been strongly associated with DM. Furthermore, anti-SSA/Ro52 antibody has been reportedly associated with DM. A 49-year-old woman presented with cough, expectoration, and dyspnea. Relevant examinations revealed elevated levels of muscle enzyme, double-positive anti-MDA5 and anti-SSA/Ro52 antibodies, positive rheumatoid factor, and a high titer of anti-citrullinated protein antibody. DM overlapping rheumatoid arthritis with ILD was confirmed. We suggest the use of glucocorticoids combined with immunosuppressant therapy, supplemented with gastric and liver protection, and recommend the use of intravenous immunoglobulins and rituximab.

Successful rituximab treatment for severe rapidly progressive interstitial lung disease with anti-MDA5 antibody-positive juvenile dermatomyositis: a case report and literature review

BACKGROUND

Rapidly progressive (RP) interstitial lung disease (ILD) is a life-threatening complication of juvenile dermatomyositis (JDM); however, it is generally refractory to treatment; to the best of our knowledge, no evidence-based treatment has been established for RP-ILD yet. We present the case of a 2-year-old girl with RP-ILD who showed resistance to treatment with methylprednisolone, cyclosporine A, cyclophosphamide, immunoglobulin, and plasma exchange (PE) and was finally treated with extracorporeal membrane oxygenation. We further present a literature review of 18 cases of JDM with RP-ILD.

CASE PRESENTATION

A 2-year-old girl presented with malar rash, mild muscle weakness, and weight loss for a few months before admission. She had a history of dry cough and dyspnea for a few days, followed by rapid respiratory failure. The patient was diagnosed with JDM with RP-ILD through physical examination (malar rashes and Gottron's sign) and based on the finding of myositis on femoral magnetic resonance imaging, elevated levels of serum muscle enzymes, positive anti-melanoma differentiation-association gene 5 (MDA5) antibody (> 7,500 index), elevated level of Krebs von den Lungen-6 glycoprotein (KL-6; 3,420 U/mL), and extensive ground-glass opacities with consolidation in the bilateral lungs on chest high-resolution computed tomography. She received combination therapy, including methylprednisolone pulse therapy, followed by oral prednisolone and intravenous cyclosporine A, cyclophosphamide, and immunoglobulin. On day 11 of hospitalization, she was placed on ventilation support and PE was initiated. However, her respiratory condition continued to deteriorate and veno-venous extracorporeal membrane oxygenation was started on day 24 of hospitalization. Rituximab was administered on day 28. After 2 weeks of rituximab therapy initiation, her respiratory condition showed gradual improvements. Eventually, on day 52 of hospitalization, the patient could be weaned off extracorporeal membrane oxygenation. Finally, she was discharged with minimal ventilation support and no neurological complications 11 months after admission.

CONCLUSIONS

Our literature review suggest that JDM with RP-ILD has a high mortality rate. In JDM, rituximab may be a promising treatment option for RP-ILD. In the future, the efficacy of rituximab in the early phases of ILD should be investigated.

Anti-MDA5 Amyopathic Dermatomyositis-A Diagnostic and Therapeutic Challenge

Clinically amyopathic Dermatomyositis (CADM) is a rare subtype of idiopathic inflammatory myositis, associated with no muscular manifestations, which is more frequent in Asian women. Anti-melanoma differentiation-associated gene 5 (MDA5) antibodies are a recently discovered type of specific autoantibodies associated with myositis. The anti-MDA5 DM was initially described in Japan and later it was discovered that the target antigen was a protein implicated in the innate immune response against viruses, that is encoded by the melanoma differentiation-associated gene 5. Anti-MDA5 DM is characteristically associated with distinguished mucocutaneus and systemic manifestations, including skin ulcerations, palmar papules, arthritis, and interstitial-lung disease. Patients with anti-MDA5 positivity have a high risk of developing rapid progressive interstitial-lung disease (RP-ILD), with a poor outcome. As a result, despite high mortality, diagnosis is often delayed, necessitating increased awareness of this possible condition. Despite a severe course of lung disease and an increased mortality rate, there is currently no standard treatment. Recent insights based on observational studies and case reports support combined therapy with immunosuppressive drugs and corticotherapy, as soon as the symptoms appear. The aim of this paper is to describe anti-MDA5 DM, focusing on the recent literature about the unique clinical manifestations and therapeutic options, starting from a severe clinical case diagnosed in our Rheumatology Department.

Autoantibodies: Pathogenic or epiphenomenon

Idiopathic inflammatory myopathies (IIM) are heterogeneous autoimmune diseases. There are distinct subgroups, including antisynthetase syndrome, dermatomyositis, polymyositis, immune-mediated necrotizing myopathy, and sporadic inclusion body myositis. In patients with IIM, autoantibodies are present in up to 80% of the patients. These autoantibodies are often characterized as myositis-specific autoantibodies (MSA) or myositis-associated autoantibodies (MAA). The recognition of the importance of autoantibodies, especially MSA, is increasing in recent years. In this chapter, we provide an overview of the MSAs, including some new autoantibodies of interest as they target mainly muscle-specific autoantigen, in clinical classification, the measurement of the disease activity, and a possible role in the pathogenesis in the patients with IIM.

A New Predictive Model for the Prognosis of MDA5+ DM-ILD

Purpose

The purpose of this study is to analyze clinical information and combine significant parameters to generate a predictive model and achieve a better prognosis prediction of dermatomyositis-associated interstitial lung disease with positive melanoma differentiation-associated gene 5 antibody (MDA5⁺ DM-ILD) and stratify patients according to prognostic risk factors appropriately.

Methods

We retrospectively reviewed 63 patients MDA5⁺ DM-ILD who were treated in our hospital from January 2018 to January 2021. Our study incorporated most clinical characteristics in clinical practice to explore the associations and predictive functions of clinical characteristics and prognosis. Student's t-test, Mann-Whitney U-test, chi-squared test, Pearson correlation analysis, Cox regression analysis, R, receiver operating characteristic curves (ROC curves), and Kaplan-Meier survival curves were performed to identify independent predictors for the prognosis of MDA5⁺DM-ILD.

Results

In all the 63 patients with MDA5⁺DM-ILD, 44 improved but 19 did not. Poor prognosis was found more frequently in patients who were older, clinically amyopathic variant of dermatomyositis (CADM), and/or with short duration, short interval of DM and ILD, long length of stay, fever, dyspnea, non-arthralgia, pulmonary infection, pleural effusion (PE), high total computed tomography scores (TCTs), ground-glass opacity (GGO), consolidation score, reticular score and fibrosis score, decreased forced vital capacity (FVC), forced expiratory volume in 1s (FEV1), albumin, A/G, glomerular filtration rate (GFR) and tumor necrosis factor α (TNFα), high titer of anti-MDA5, proteinuria, high levels of monocyte, lactate dehydrogenase (LDH), ferritin (FER), neuron specific enolase (NSE) and glucocorticoid, antibiotic, antiviral, and non-invasive positive pressure ventilation (NPPV). The multivariate Cox regression analysis demonstrated that duration, fever, PE, TCTs and aspartate transaminase (AST) were independent predictors of poor prognosis in patients with MDA5⁺DM-ILD. The nomogram model quantified the risk of 400-day death as: duration ≤ 4 months (5 points), fever (88 points), PE (21 points), TCTs ≥10 points (22 points), and AST ≥200 U/L (100 points) with high predictive accuracy and convenience. The ROC curves possessed good discriminative ability for combination of fever, PE, TCTs, and AST, as reflected by the area under curve (AUC) being.954, 95% CI 0.902–1.000, and sensitivity and specificity being 84.2 and 94.6%, respectively.

Conclusion

We demonstrated that duration, fever, PE, TCTs, and AST could be integrated together to be independent predictors of poor prognosis in MDA5⁺ DM-ILD with highly predictive accuracy.

Interstitial lung disease with anti-melanoma differentiation-associated gene 5 antibody after allogeneic hematopoietic stem cell transplantation

Anti-melanoma differentiation-associated gene 5 (MDA5) antibody is one of auto-immune antibodies which is associated with a rare subtype of dermatomyositis (DM), and MDA5-DM is well-characterized by rapid progressive interstitial lung disease (ILD) which in part resembles pulmonary complications after allogeneic hematopoietic cell transplantation (allo-HCT). However, previous studies about anti-MDA5 antibody after allo-HCT were extremely limited. Here, we present 4 cases of ILD with anti-MDA5 antibody after allo-HCT. All of the cases showed rapidly progressive clinical course and 3 of 4 cases died despite intensive immunosuppressive therapies which included prednisolone, cyclophosphamide and calcineurin inhibitor. Additionally, 3 of 4 cases had tested positive for anti-MDA5 antibody by using cryopreserved plasma which were collected about 2–3 months before the diagnosis of MDA5-DM-ILD. It suggests that an inflammatory condition due to MDA5-DM-ILD might have sub-clinically occurred before the development of respiratory failure. The current cases suggest that the clinical feature was relatively similar to classical MDA5-DM-ILD, although it is difficult to distinguish MDA5-DM-ILD from chronic GVHD and other pulmonary complications after allo-HCT. Since clinical courses of MDA5-DM-ILD is considerably aggressive, it is important to discriminate MDA5-DM-ILD from other complications after allo-HCT.

Treatment approach to connective tissue disease-associated interstitial lung disease

Interstitial lung disease (ILD) is a common manifestation in connective tissue diseases (CTD), such as rheumatoid arthritis (RA), systemic sclerosis (SSc), and inflammatory myositis (IM). ILD is associated with significant morbidity and mortality in nearly all CTD highlighting the critical need for effective treatment strategies in this patient population. In this review, we will summarize the approach to treatment when there is concern for CTD-ILD and highlight recent advancements in therapeutics within various forms of CTD-ILD.

Pathophysiological Mechanisms and Treatment of Dermatomyositis and Immune Mediated Necrotizing Myopathies: A Focused Review

Idiopathic inflammatory myopathies (IIM), collectively known as myositis, are a composite group of rare autoimmune diseases affecting mostly skeletal muscle, although other organs or tissues may also be involved. The main clinical feature of myositis is subacute, progressive, symmetrical muscle weakness in the proximal arms and legs, whereas subtypes of myositis may also present with extramuscular features, such as skin involvement, arthritis or interstitial lung disease (ILD). Established subgroups of IIM include dermatomyositis (DM), immune-mediated necrotizing myopathy (IMNM), anti-synthetase syndrome (ASyS), overlap myositis (OM) and inclusion body myositis (IBM). Although these subgroups have overlapping clinical features, the widespread variation in the clinical manifestations of IIM suggests different pathophysiological mechanisms. Various components of the immune system are known to be important immunopathogenic pathways in IIM, although the exact pathophysiological mechanisms causing the muscle damage remain unknown. Current treatment, which consists of glucocorticoids and other immunosuppressive or immunomodulating agents, often fails to achieve a sustained beneficial response and is associated with various adverse effects. New therapeutic targets have been identified that may improve outcomes in patients with IIM. A better understanding of the overlapping and diverging pathophysiological mechanisms of the major subgroups of myositis is needed to optimize treatment. The aim of this review is to report on recent advancements regarding DM and IMNM.

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.

Clinical features and immune-related protein patterns of anti-MDA5 positive clinically amyopathic dermatomyositis Dutch patients

OBJECTIVES

The presence of melanoma differentiation-associated protein 5 (MDA5) antibodies in patients with dermatomyositis (DM) is associated with the development of a rapidly progressive interstitial lung disease (RPILD), unresponsive to conventional treatment. We characterize patients and provide more insight into potential biomarkers to identify patients with RPILD.

METHODS

Patients diagnosed with anti-MDA5 positive DM between December 2015 and November 2017 were included in this study. Clinical data were retrospectively retrieved from medical records. 180 immune-related markers were measured in sera of 16 patients and 15 healthy controls using proximity extension assay based technology.

RESULTS

Twenty patients were included, with a median time from symptoms till diagnosis of 4 months. All patients had clinically amyopathic DM. Interstitial lung disease (ILD) was present at diagnosis in 94% of the patients, 45% presented with RPILD. The mortality rate was 35% within 4 months after diagnosis and respiratory failure was the main cause of death in these patients. Furthermore, unsupervised analysis revealed that patients with RPILD show clearly different inflammatory serum profiles than healthy controls. In addition, in comparison to healthy controls, the interferon, Interleukin (IL)1, IL10 and IL18 signalling pathways are different regulated in anti-MDA5 positive patients.

CONCLUSION

In this Dutch anti-MDA5 positive CADM cohort, one third of the patients died due to RPILD soon after diagnosis, which underlines the severity of this disease. In addition, we have found several possible pathways that are differentially regulated in RPILD vs no RPILD DM and healthy controls. These markers await further validation before clinical use.

Rituximab in the Treatment of Interstitial Lung Diseases Related to Anti-Melanoma Differentiation-Associated Gene 5 Dermatomyositis: A Systematic Review

Objective

The effectiveness of rituximab in anti-melanoma differentiation-associated gene 5 (MDA5) dermatomyositis (DM) with interstitial lung disease (ILD) has been explored only in isolated case reports and small series. This paper aims to review the current evidence regarding rituximab (RTX) use in the treatment of ILD related to anti-MDA5 DM (anti-MDA5 DM-ILD).

Methods

We conducted a review by searching PubMed, Web of Science, Embase, and Cochrane for articles with information on patients with anti-MDA5 DM and RTX treatment, published until August 2021, in English language. The selected studies listed variation in chest high-resolution computed tomography (HRCT) and/or pulmonary function test (PFT) as a primary outcome, in patients with anti-MDA5 DM-related ILD after using RTX.

Results

Of the 145 potentially eligible articles, 17 were selected. The information gathered from a total of 35 patients with anti-MDA5 DM-ILD was reviewed, including 13 men and 22 women. Patient age at onset was 47.60 ± 13.72 years old. A total of 11.43% (4/35) of the patients were found to have chronic ILD (C-ILD) and 88.57% (31/30) exhibited rapidly progressive ILD (RP-ILD). Most patients (29/30) had typical DM rashes. Prior to RTX administration, the majority of patients (27/35) were treated with medium- or high-dose glucocorticoids and at least one additional immunotherapeutic agent. With regard to RTX efficacy for ILD in anti-MDA5 DM, 71.43% (25/35) of the patients responded to treatment. Skin rash also improved in more than half of the patients after RTX treatment. The most common side effects were infections, reported by 37.14% (13/35) of the patients after using RTX.

Conclusion

As a CD20 targeting drug, RTX is a promising therapeutic tool for anti-MDA5 DM-ILD, although the risk of infections should be considered before treatment. Further prospective controlled studies are required to evaluate the optimal RTX treatment regimen.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021289714, identifier CRD42021289714.

Quantitative CT analysis of interstitial pneumonia in anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis: a single center, retrospective study

INTRODUCTION

This study aimed to assess the utility of quantitative high-resolution computed tomography (HRCT) for determining the clinical course of anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis-associated interstitial lung disease (MDA5⁺ ILD).

METHOD

This study retrospectively analyzed the data of 34 patients with MDA5⁺ ILD to determine the association between the clinical findings and extent of ILD via quantitative CT analysis at baseline and short-term follow-up. Quantified HRCT scores were evaluated as the lung severity score (LSS), percentage of opacity, and percentage of high opacity.

RESULTS

Thirty-four patients underwent follow-up CT scans 35 (range: 14-78) days after diagnosis. Patients who died of rapidly progressive ILD had higher LSS (p < 0.01), percentage of opacity (p < 0.01), percentage of high opacity (p = 0.01), total ground-glass opacity score (p = 0.01), serum C-reactive protein (CRP) (p = 0.03), and alveolar-arterial oxygen difference (Aa-DO2) (p = 0.01) at follow-up than those who survived. Quantified HRCT scores correlated with serum CRP and Aa-DO2 levels at follow-up. LSS at follow-up (AUC = 0.844, p < 0.01) was the best predictor of death in MDA5⁺ ILD patients. Patients with an LSS of > 6.5 at follow-up had higher mortality than those with an LSS of ≤ 6.5, especially when receiving triple therapy. In multivariate analysis, an LSS of > 6.5 at follow-up was significantly associated with a poor outcome.

CONCLUSIONS

Quantitative CT analysis of MDA5⁺ ILD is useful for the objective assessment of respiratory status and disease activity. Short-term HRCT evaluation, particularly LSS, is most important in predicting its clinical course during triple therapy. Key Points • Quantitative CT analysis plays an important role in evaluating the clinical course of anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis-associated interstitial lung disease (MDA5⁺ ILD). • Quantified HRCT scores, particularly lung severity score, at short-term intervals from diagnosis can help to predict prognosis after triple therapy in MDA5⁺ ILD.

Myositis Antibodies and Interstitial Lung Disease

BACKGROUND

Interstitial lung disease (ILD) comprises a heterogeneous group of inflammatory and fibrotic conditions, often resulting in progressive lung function decline and increased mortality. Connective tissue disease (CTD) should be considered in all patients with ILD, as distinguishing between CTD-ILD and other forms of fibrotic lung disease has important therapeutic and prognostic implications. The idiopathic inflammatory myopathies (IIM) represent a CTD subtype of growing interest to ILD experts. The expansion and availability of myositis-specific and myositis-associated antibody testing has allowed for improved disease detection and characterization.

CONTENT

In this review, we highlight the relationship between myositis antibodies and ILD. Select forms of IIM, such as the antisynthetase syndrome and clinically amyopathic dermatomyositis can present with rapidly progressive ILD, warranting timely disease diagnosis and management. Disease phenotypes, prevalence, laboratory testing, prognosis, and management strategies are described according to select myositis antibodies.

SUMMARY

Myositis antibodies provide valuable information for clinicians managing patients with ILD. This review aims to increase awareness of their role in disease detection, pathophysiology, and possibly therapeutics.

A Case of Clinically Amyopathic Dermatomyositis that was Refractory to Intensive Immunosuppressive Therapy including Tofacitinib, but Successfully Treated with Plasma Exchange Therapy

Clinically amyopathic dermatomyositis (CADM) patients often develop rapidly progressive interstitial lung disease (RP-ILD). A high level of anti-melanoma differentiation-associated gene 5 antibodies (anti-MDA5 Ab) before treatment is associated with RP-ILD development, a poor treatment response, and poor survival. The prognosis of CADM patients remains poor due to ILD even with combined intensive immunosuppressive therapy. Recently, several additional therapies, including tofacitinib (TOF) and plasma exchange (PE) therapy, have been reported to be effective. We herein report a case of CADM-ILD with a high level of anti-MDA5 Ab that was refractory to combined intensive immunosuppressive therapy including TOF, but successfully treated with PE. The following are possible reasons why TOF was ineffective: 1) cytokines that were not suppressed by TOF played an important role in RP-ILD; 2) TOF was administered later than previously reported; and 3) TOF did not suppress pathological substances such as antibodies. On the other hand, PE removes cytokines and various pathological substances. Therefore, PE may be a more reasonable additional therapy for intractable CADM-ILD.

Dermatomyositis Which Was Double Positive for Anti-MDA5 and Anti-ARS Antibodies That Was Successfully Treated by Intensive Immunosuppressive Therapy

Myositis-specific autoantibody is associated with the clinical phenotype and prognosis of dermatomyositis. Anti-melanoma differentiation-associated gene 5 (MDA5) and anti-aminoacyl-tRNA synthetase (ARS) antibodies are generally mutually exclusive. We herein present an extremely rare case of dermatomyositis which showed double positivity for anti-MDA5 and anti-ARS antibodies. There have been very few reported cases of double positive anti-MDA5, anti-ARS antibodies. In such cases, the clinical characteristics of each autoantibody can coexist. Thus, we should pay attention to the rapidly progressing features of anti-MDA5 as well as the chronic relapsing features of anti-ARS for the better management of this rare condition.

Intravenous immunoglobulin for interstitial lung diseases of anti-melanoma differentiation-associated gene 5-positive dermatomyositis

OBJECTIVE

Rapidly progressive interstitial lung disease (RP-ILD) in dermatomyositis (DM) patients positive for anti-melanoma differentiation-associated gene 5 (anti-MDA5) autoantibody (MDA5-DM) often have poor prognosis, frequently fatal. As there is a scarcity of data regarding the effect of intravenous immunoglobulin (IVIG) on RP-ILD in MDA5-DM patients (MDA5-RPILD), we conducted this study to determine the efficacy of a IVIG add-on initial treatment.

METHODS

Patients with newly-onset MDA5-RPILD from September 2018 to June 2020 were retrospectively reviewed for 6 months in the First Affiliated Hospital of Zhengzhou University. They were divided into two groups: IVIG and non-IVIG groups. The major measurement of treatment outcome was the difference in the mortality in 3-month and 6-month between two group patients. Other relevant indicators were also recorded, including the incidence of infection, the dosages of GCs, the remission rate and the variables in laboratory data.

RESULTS

The IVIG group (n = 31) showed significantly lower 6-month mortality rate than the non-IVIG group (n = 17) (22.6% vs 52.9%; p= 0.033). The IVIG group patients had a higher remission rate at 3 months (71.0% vs 41.2%; p= 0.044). Gradual reduction was observed in the first 3 months with regards to the titer of anti-MDA5 autoantibody, the serum level of ferritin, and the GGO scores.

CONCLUSION

IVIG adjunct therapy is a very effective first-line treatment for patients with MDA5-RPILD. IVIG may increase the survival and remission rate by lowering ferritin concentration, anti-MDA5 titer and GGO score.

Dermatomyositis With Anti-MDA5 Antibodies: Bioclinical Features, Pathogenesis and Emerging Therapies

Anti-MDA5 dermatomyositis is a rare systemic autoimmune disease, historically described in Japanese patients with clinically amyopathic dermatomyositis and life-threatening rapidly progressive interstitial lung disease. Subsequently, the complete clinical spectrum of the disease was enriched by skin, articular and vascular manifestations. Depending on the predominance of these symptoms, three distinct clinical phenotypes with different prognosis are now defined. To date, the only known molecular component shared by the three entities are specific antibodies targeting MDA5, a cytosolic protein essential for antiviral host immune responses. Several biological tools have emerged to detect these antibodies, with drawbacks and limitations for each of them. However, the identification of this highly specific serological marker of the disease raises the question of its role in the pathogenesis. Although current knowledge on the pathogenic mechanisms that take place in the disease are still in their enfancy, several lines of evidence support a central role of interferon-mediated vasculopathy in the development of skin and lung lesions, as well as a possible pathogenic involvement of anti-MDA5 antibodies. Here, we review the clinical and biological evidences in favor of these hypothesis, and we discuss the contribution of emerging therapies that shed some light on the pathogenesis of the disease.