Autoantibodies to a 140-kd polypeptide, CADM-140, in Japanese patients with clinically amyopathic dermatomyositis

Refractory cutaneous ulcers in anti-MDA5 dermatomyositis were not associated with rapidly progressive interstitial lung disease, and responded to tadalafil

OBJECTIVES

The purpose of this study was to analyze the characteristics of an ulcerative rash in dermatomyositis (DM) patients with anti-melanoma differentiation-associated gene 5 (anti-MDA5) antibody and to assess the efficacy of tadalafil in the management of refractory cutaneous ulcers.

METHODS

Medical records of DM patients with anti-MDA5 antibody were reviewed. Skin rash data, radiologic characteristic and serum markers were collected. Patients with refractory cutaneous ulcers treated with tadalafil were reviewed retrospectively.

RESULTS

Eighty-two consecutive cases with anti-MDA5-antibody positive DM (anti-MDA5 DM) were identified, including 62 (75.6 %) female patients. Approximately 95.0 % of the patients had interstitial lung disease (ILD) and 45.1 % had rapidly progressive ILD (RP-ILD). All patients (100 %) had typical skin rashes, such as Gottron's sign (87.8 %), heliotrope sign (69.5 %), and the holster sign (24.4 %). Twenty-six patients (31.7 %) had cutaneous ulcers. Univariate analysis showed that ulcer patients were prone to Gottron's sign (p = 0.026), perlungual erythematosus (p = 0.007), and arthritis (p = 0.031), while shortness of breath after exercise (p = 0.027) and RP-ILD (p = 0.024) are more likely to appear in patients with non-skin ulcers. Among the anti-MDA5 DM patients with skin ulcers, 10 (38.5 %) were refractory cutaneous ulcers, including five male patients. After tadalafil was added, eight (80 %) patients showed improvement in the physician global assessment (PGA), Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI) score and the patient's pain score using the visual analog score (p-VAS), within one to two months. In addition, the refractory cutaneous ulcers of five patients completely resolved after treatment.

CONCLUSIONS

This study found that ulcerative rash in anti-MDA5 DM may not be associated with RP-ILD. The results also suggest that tadalafil may be a useful therapy for refractory cutaneous ulcers.

External validation of the 2017 EULAR/ACR classification criteria for idiopathic inflammatory myopathies in anti-MDA5 antibody-positive interstitial lung disease patients: A multicenter retrospective cohort study in China

The aim of this study was to assess the 2017 EULAR/ACR classification criteria performance for determining idiopathic inflammatory myopathies (IIMs) in a cohort of patients with anti-MDA5 antibody-positive IIM-related interstitial lung disease (anti-MDA5+IIM-ILD). The outcomes of patients, who did not meet the EULAR/ACR criteria, and who had interstitial pneumonia and exhibited an autoimmune phenotype associated with anti-MDA5 positivity were also investigated.

METHODS

This retrospective study recruited adult patients from four hospitals in China who were diagnosed with anti-MDA5 antibody-positive IIM-related interstitial lung disease. Data on disease manifestations, laboratory findings, and imaging findings were collected through electronic medical records. The performance and consistency of the 2017 EULAR/ACR classification criteria were compared with those of the Bohan/Peter criteria combined with Sontheimer's CADM criteria. Additionally, this study evaluated the performance of incorporating anti-MDA5 antibodies into the EULAR/ACR criteria and explored the criteria proposed by Casal-Domingez based on myositis-specific antibodies (MSAs). Finally, clinical characteristics and prognoses were compared between patients with MDA5+IIM-ILD who met the EULAR/ACR criteria and those who did not meet the EULAR/ACR criteria.

RESULTS

A total of 250 patients with anti-MDA5-related IIM-ILD, including those with dermatomyositis (DM, 23.6 %) and clinically amyopathic dermatomyositis (CADM, 76.4 %), were recruited. Of these, 175 (70 %) and 64 (25.7 %) patients met the EULAR/ACR and Bohan/Peter criteria, respectively. According to Sontheimer's CADM criteria, 60.4 % of patients could be classified according to the Bohan and Peter criteria. Thirty percent of the anti-MDA5 antibody-positive patients did not meet the EULAR/ACR criteria but met the IPAF criteria. The sensitivity of the EULAR/ACR criteria increased to 99.2 % when anti-JO-1 antibodies were replaced with anti-MDA5 antibodies. In this cohort, a sensitivity of 100 % was obtained using the Casal-Domingez criteria. There were no significant differences in clinical characteristics or prognoses between MDA5+IIM-ILD patients who met the EULAR/ACR criteria, those who did not meet the criteria, and those who met the IPAF criteria.

CONCLUSION

Approximately 30 % of clinically diagnosed anti-MDA5 antibody-positive IIM-ILD patients cannot be classified according to the EULAR/ACR criteria, suggesting that such patients should be managed as IIM-ILD patients. Modifying the existing criteria by including other MSAs, such as anti-MDA5 antibodies, as one of the scoring criteria is recommended. Future IIM guidelines should consider incorporating ILD into the diagnostic criteria.

Contrast of muscle magnetic resonance imaging and pathological findings of muscle tissue in patients with anti-aminoacyl transfer RNA synthetase antibodies

OBJECTIVES

To determine whether magnetic resonance imaging (MRI) findings reflect the pathological features of inflammatory myopathies.

METHODS

Patients with idiopathic inflammatory myopathies (IIMs) diagnosed using the 2017 European League Against Rheumatism/American College of Rheumatology classification criteria in our university between 2005 and 2020 were retrospectively reviewed. IIMs were subclassified into the anti-aminoacyl transfer RNA synthetase syndrome [anti-synthetase syndrome (ASSD)], immune-mediated necrotizing myositis, dermatomyositis (DM), and others. Fat-suppressed T2-weighted MRI and muscle biopsy specimens were assessed in IIMs followed by the comparison among the four subgroups.

RESULTS

MRI findings were available for 62 patients and histopathological findings were available for 27 patients. Perifascicular atrophy or necrosis in the muscle tissues from the patients with IIM was more frequently observed in patients with subcutaneous and fascial high signal intensity (HSI) on MRI than those without. Four-group comparison among ASSD, immune-mediated necrotizing myositis, DM, and others revealed that HSI in fasciae on MRI was more frequently observed in patients with ASSD and DM than in others. Perifascicular atrophy or necrosis in muscle tissues was more frequently observed in patients with ASSD than in others.

CONCLUSION

Patients with ASSD had distinct MRI features compared with anti-aminoacyl transfer RNA synthetase negative patients. The fascial HSI on MRI may reflect distinctive pathological features of muscles.

Clinical features and survival analysis of 40 cases of anti-MDA5 antibody-positive dermatomyositis complicated with interstitial lung disease

BACKGROUND

Several studies have shown that patients with anti-MDA5 antibody-positive dermatomyositis (anti-MDA5 antibody + DM) have an increased risk of developing rapid progression of interstitial lung disease (RPILD), which is associated with poor prognosis and high mortality. However, diagnosis and treatment are often delayed due to atypical early clinical features and heterogeneity. Therefore, clinical features should be identified to establish a prognosis model for early identification and intervention, thereby improving the clinical prognosis of patients.

OBJECTIVES

The study aimed to investigate the clinical features, risk factors, treatment strategy, and construct a survival prognosis model for anti-MDA5 antibody + DM patients with ILD.

METHODS

A total of 40 anti-MDA5 antibody + DM-ILD patients admitted to the Department of Pulmonary and Critical Care Medicine and the Department of Rheumatology and Immunology in the Second Affiliated Hospital of Xi 'an Jiaotong University from September 2018 to May 2022 were retrospectively analyzed. Prognostic factors correlated with overall survival (OS) during hospitalization were identified by multivariate Cox regression analysis, and a nomogram was established. The nomogram was internally validated using C-index and time-dependent (at 1-, 2-, and 3- months) calibration curves with 1000 iterations of bootstrap resampling. Moreover, the optimal truncation values for continuous variables and Kaplan-Meier (K-M) curves were determined, which were used to analyze the difference in survival between groups. Finally, time-dependent decision curve analysis (DCA) was employed to validate the clinical value of the nomogram.

RESULTS

Significant differences were found between the survival group and the non-survival group in terms of age, oxygenation index, extent of lung lesions, diffuse alveolar damage (DAD) and nonspecific interstitial pneumonia (NSIP), and LDH, GLU, CEA, ferritin, CRP levels in serum (P < 0.05). Multivariate regression analysis revealed that increased NSIP in high-resolution computed tomography (HRCT) and ALT,LDH,CEA,CRP were risk factors for poor prognosis (P < 0.05). A nomogram diagram was constructed according to the final multiple Cox model to predict the 1-, 2-, and 3-month OS. According to ALT, AST, LDH, CEA, and CRP cutoff values, the KM algorithm was used to estimate the survival curve (P < 0.05). DCA curves were drawn for the model-dependent variables included treatment style, NSIP, ALT, AST, LDH, CEA, and CRP. This indicated that the nomogram yielded a higher net benefit compared to other single prognostic factors, and the cutoff value grouping model showed better practical application value. Combined treatment with glucocorticoids and immunosuppressants was a protective factor for long-term survival. Survival analysis indicated that patients with anti-MDA5 + DM-ILD could benefit from combined treatment for longer survival.

CONCLUSIONS

Anti-MDA5 antibody + DM is prone to interstitial lung disease, poor prognosis, and high mortality. Risk prediction model could help us paying attention to these features which may allow the early identification of high-risk patients and promote timely diagnosis and treatment.

The Pancreatitis Puzzle: Antimelanoma Differentiation-Associated Gene-5 Dermatomyositis Unveiled

Antimelanoma differentiation-associated gene (MDA)-5 dermatomyositis, a subtype of inflammatory myopathy, is associated with interstitial lung disease and distinctive skin findings. We report a 39-year-old woman presenting with pancreatitis as the first presentation of anti-MDA-5 dermatomyositis. The patient had no pancreatitis risk factors, and her muscle enzymes were normal. Months later, she developed characteristic skin lesions, leading to the diagnosis of anti-MDA-5 dermatomyositis. This case emphasizes the need to recognize key skin lesions, such as ulcers, palmar, and kissing papules while maintaining a broad differential to identify atypical presentations such as pancreatitis, which can aid in the timely diagnosis and management of anti-MDA-5 dermatomyositis.

Neutrophil-to-lymphocyte ratio and short-term mortality in patients having anti-MDA5-positive dermatomyositis with interstitial lung disease: a retrospective study

BACKGROUND

In this study, we aimed to explore the association between baseline and early changes in the neutrophil-to-lymphocyte ratio (NLR) and the 30-day mortality rate in patients having anti-melanoma differentiation-associated gene 5 (MDA5)-positive dermatomyositis with interstitial lung disease (DM-ILD).

METHODS

Overall, 263 patients with anti-MDA5 DM-ILD from four centers in China were analyzed. Multivariate logistic regression analysis was used to evaluate the impact of baseline NLR on the 30-day mortality rate in patients with anti-MDA5-positive DM-ILD. Furthermore, a generalized additive mixed model (GAMM) was applied to compare the NLR variations over time between 30-day survival group and non-survival group.

RESULTS

Two hundred sixty-three patients with anti-MDA5-positive DM-ILD were divided into different groups based on their NLR and whether they survived or not within 30 days. The multivariate logistic regression analysis, accounting for confounding factors, identified an elevated baseline NLR as a prognostic indicator for 30-day mortality in patients with anti-MDA5-positive DM-ILD (hazard ratio 2.68, 95% confidence interval [CI] 1.18,6.00, P = 0.019). Furthermore, the GAMM results indicated that the NLR gradually increased more in the non-survival group compared with the survival group within 14 days of admission, with a daily average increase of 1.03 (β = 1.03; 95% CI, 0.75-1.31; P < 0.001).

CONCLUSIONS

We found that an elevated baseline NLR and its progressive increase are associated with 30-day mortality in patients with anti-MDA5-positive DM-ILD.

Subcutaneous Emphysema and Severe Interstitial Lung Disease in the Setting of Anti-MDA 5 Positive Dermatomyositis in a Hispanic Patient

Antimelanoma differentiation-associated gene 5 (MDA5) dermatomyositis (DM) is a subtype of DM associated with characteristic mucocutaneous features. These individuals have an increased risk of developing interstitial lung disease (ILD) that ultimately leads to a complicated clinical course. Certain clinical findings suggest anti-MDA5 positive DM over anti-MDA5 negative DM, including cutaneous ulcers, diffuse nonscarring alopecia, and panniculitis. ILD and pneumomediastinum are known to be two of the most important pulmonary complications of anti-MDA5 DM because of the possibility of a rapidly progressive course and poor survival. This case outlines the unique presentation of pneumomediastinum, subcutaneous emphysema, and ILD in a patient with anti-MDA5 positive DM.

Successful treatment of anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis with rapidly progressive interstitial lung disease complicated by bilateral breast cancer following the additional tofacitinib: A case report

Anti-melanoma differentiation-associated gene 5 (MDA-5) antibody-positive dermatomyositis (MDA5-DM) often causes rapidly progressive interstitial lung disease (RP-ILD). Although cancer complications in MDA5-DM are less frequently reported compared to other forms of DM, they do occur. For MDA5-DM patients with cancer, particularly in paraneoplastic settings, the primary treatment strategy often targets the malignancy first. However, surgery, chemotherapy, and radiotherapy carry significant risks of exacerbating ILD, especially in patients with respiratory failure. Despite improved prognosis with initial immunosuppressive combination therapy, some cases of MDA5-DM with RP-ILD remain refractory to treatment. Recent studies have shown the potential benefit of Janus kinase (JAK) inhibitors for refractory cases, though their impact on cancer progression remains a concern. We report a 48-year-old woman with MDA5-DM, RP-ILD, and bilateral breast cancer. Due to her respiratory condition, radical surgery and chemotherapy were initially not possible. Endocrine therapy and immunosuppressive therapy were administered, but the disease remained refractory. Tofacitinib, combined with plasma exchange, improved her ILD, allowing for bilateral mastectomy. One year later, MDA5 antibody titers became negative, and glucocorticoids were discontinued after two years. Three years later, neither MDA5-DM nor breast cancer has recurred. This is the first report of MDA5-DM complicated by breast cancer, and the first use of JAK inhibitors in such a case. Effective treatment requires close collaboration with oncologists to balance the risks and benefits of therapy in cases of MDA5-DM with RP-ILD and cancer.

Antimelanoma differentiation-associated gene 5 (anti-MDA5) antibody-positive dermatomyositis: clinical features and outcomes in a racially diverse patient cohort

BACKGROUND

The anti-melanoma differentiation-associated gene 5 (anti-MDA5) antibody-positive dermatomyositis is known for its association with rapidly progressive interstitial lung disease (RP-ILD) and ulcerative skin lesions, often presenting with or without muscle involvement. The aim of this study was to identify distinct clinical and laboratory features that could be used to evaluate disease progression in an ethnically diverse cohort of anti-MDA5 dermatomyositis patients at a U.S. academic center.

METHODS

A retrospective chart review was conducted on dermatomyositis patients hospitalized at our institution between January 2014 and June 2023. The data were analyzed via Fischer's exact test and a t test.

RESULTS

Among the 195 dermatomyositis patients reviewed, 22 tested positive for the MDA5 antibody, comprising of thirteen adults and nine pediatric patients. Myositis was significantly more common in pediatric patients than in adult patients (p = 0.002). RP-ILD was more frequently observed in adult patients of African ancestry (including both Black Hispanic and Black non-Hispanic individuals) (p = 0.04). There was a significant association noted between Raynaud's phenomenon and ILD (p = 0.02). The overall mortality rate of 13.6% was more favorable than the previously reported rates of 40-60%.

CONCLUSION

This study enhances our understanding of the disease by emphasizing potential racial and demographic variations, as well as delineating the similarities and differences between adult and pediatric populations.

Low serum S100A6 levels are associated RP-ILD risk in anti-MDA5-positive dermatomyositis

INTRODUCTION

Anti-MDA5-positive dermatomyositis (anti-MDA5-DM) is a rare autoimmune disease that often leads to rapid-progressive interstitial lung disease (RP-ILD). The lack of effective prediction and treatment methods makes RP-ILD a major risk factor for death in patients with this condition. S100A6 is a member of the S100 Ca2 + - binding protein family, which plays important roles in inflammation, tumor, injury, and fibroblast reparation. This study aims to explore the correlation between serum S100A6 and RP-ILD in anti-MDA5-DM, and to determine whether S100A6 can be used as a specific biomarker to predict RP-ILD.

METHODS

The authors enrolled 80 participants, including 20 healthy volunteers, 20 patients with anti-synthase syndrome, and 40 patients with anti-MDA5-positive dermatomyositis. Serum samples were collected and the levels of S100A6 were measured using ELISA. Logistic regression was used to analyze the relationship between serum S100A6 levels and RP-ILD, along with other clinical and laboratory parameters.  RESULTS: Serum S100A6 levels were significantly lower in anti-MDA5-DM patients with RP-ILD than those without RP-ILD (odds ratio:0.393 (95% CI, 0.164-0.943, p = 0.036)). High serum S100A6 level was found to be a protective factor for RP-ILD. This study shows that high serum S100A6 level may be a protective factor for RP-ILD in anti-MDA5-DM patients. Serum S100A6 may be used as a specific biomarker to predict whether RP-ILD occurs in anti-MDA5-DM. Key Points • This research discovers and reports a biomarker (S100A6) for distinguishing potential RP-ILD in Anti-MDA5 positive dermatomyositis.

Successful Treatment with Mycophenolate Mofetil in a Patieint with Anti-MDA 5 Antibody-positive Interstitial Lung Disease and Posterior Reversible Encephalopathy Syndrome

A 59-year-old woman presented with a rash on the top part of her hands and pain in the wrist joint and was diagnosed with dermatomyositis complicated by interstitial pneumonia positive for anti-melanoma differentiation-associated gene 5 (MDA-5) antibody. However, the patient reported a severe headache following treatment with oral prednisolone and tacrolimus. Posterior reversible encephalopathy syndrome (PRES) was diagnosed based on the brain magnetic resonance imaging findings. Tacrolimus was discontinued, and mycophenolate mofetil was instead administered with a favorable outcome. Mycophenolate mofetil should therefore be considered as an alternative treatment for anti-MDA-5-positive interstitial lung disease in cases where calcineurin inhibitors cannot be used.

An update on autoantibodies in the idiopathic inflammatory myopathies

Myositis-specific autoantibodies (MSAs) have become pivotal biomarkers for idiopathic inflammatory myopathies and have revolutionized understanding of the heterogeneous disease spectrum that affects both adults and children. The discovery and characterization of MSAs have substantially enhanced patient stratification based on clinical phenotype, thereby facilitating more precise diagnosis and ultimately improving management strategies. Advances in immunoassay technologies in the past 20 years have further propelled the field forward, enabling the detection of a growing repertoire of autoantibodies with high specificity and sensitivity; however, evolving research over the past decade has revealed that even within antibody-defined subsets, considerable clinical diversity exists, suggesting a broader spectrum of disease manifestations than previously acknowledged. Challenges persist, particularly among patients who are seronegative, where the failure to identify certain rare MSAs stems from the use of diverse detection methodologies and inadequate consensus-guided standardization and validation protocols. Bridging these diagnostic gaps is crucial for optimizing patient care and refining prognostic stratification in idiopathic inflammatory myopathies.

Lung ultrasound in the assessment of interstitial lung disease in patients with connective tissue disease: Performance in comparison with high-resolution computed tomography

OBJECTIVE

To investigate clinical relevance of performing lung ultrasound (LUS) in patients with connective tissue disease (CTD)-associated interstitial lung disease (ILD) in comparison with high-resolution computed tomography (HRCT).

METHODS

This single-centre study enrolled eligible patients with CTD-ILD from the prospective LUS registry. Total B-lines were detected by assessment at 14 sites via LUS. Forced vital capacity, diffusing lung capacity for carbon monoxide (DLCO), DLCO/alveolar volume, 6-minute walking distance, and the ILD-GAP index were used as ILD prognostic parameters. Correlations were examined using single and multiple regression analyses.

RESULTS

Sixty-seven patients were enrolled, including 29 with idiopathic inflammatory myopathy or anti-synthetase syndrome, 25 with systemic sclerosis (SSc), 10 with rheumatoid arthritis, and 3 with mixed CTD. The total number of B-lines correlated with ILD extent on HRCT in patients with CTD-ILD (r = 0.66; P < .001), particularly in patients with SSc-ILD (r = 0.78; P < .001). Total B-lines and ILD extent on HRCT showed comparable correlations with prognostic parameters, while multiple regression analysis revealed the limited benefit of performing LUS in addition to HRCT in predicting correlations with prognostic factors.

CONCLUSIONS

LUS serves as an alternative tool for assessing the severity and prognosis of patients with CTD-ILD.

The clinical relevance of WDFY4 in autoimmune diseases in diverse ancestral populations

WD repeat- and FYVE domain-containing protein 4 (WDFY4), coded by a gene on 10q11.23, is a member of the BEACH (Beige and Chediak-Higashi) domain-containing family. Genome-wide association studies identified WDFY4 variants as a risk factor for SLE in Asian and European populations. WDFY4 variants are also associated with RA and primary biliary cholangitis, in different ancestry populations. The WDFY4 protein plays an essential role in the cross-presentation of classic dendritic cells, reactive oxygen species-induced apoptosis of CD8+ T cells, and non-canonical autophagic activity in B cells. A novel variant rs7919656 was identified in Japanese clinically amyopathic dermatomyositis patients, with a highly expressed truncated isoform augmenting the melanoma differentiation-associated gene 5 (MDA5) signalling pathway. The same variant was later found to be significantly associated with RP-ILD in Chinese MDA5+DM patients. Here, we briefly review the association of WDFY4 with autoimmune diseases and its known function in the immune response.

Recent Updates on the Pathogenesis of Inflammatory Myopathies

PURPOSE OF REVIEW

This review aims to provide a comprehensive and updated overview of autoimmune myopathies, with a special focus on the latest advancements in understanding the role of autoantibodies. We will begin by examining the risk factors and triggers associated with myositis. Next, we will delve into recent research on how autoantibodies contribute to disease pathogenesis. Finally, we will explore the latest innovations in treatment strategies and their implications for our understanding of myositis pathogenesis.

RECENT FINDINGS

Recent research has revealed that myositis-specific autoantibodies can infiltrate muscle cells and disrupt the function of their target autoantigens, playing a crucial role in disease pathogenesis. Significant advances in treatment include CD19 CAR-T cell therapy, JAK-STAT inhibitors, and novel strategies targeting the type 1 interferon pathway in dermatomyositis. Additionally, the ineffectiveness of complement inhibitors in treating immune-mediated necrotizing myositis has challenged established views on disease mechanisms. Autoimmune myopathies are a collection of disorders significantly influenced by specific autoantibodies that drive disease pathogenesis. This review highlights the critical role of autoantibody research in deepening our understanding of these conditions and discusses recent therapeutic advancements targeting key pathogenic pathways.

Pneumocystis jirovecii pneumonia increases the 3-months mortality of anti-MDA5-antibody-positive dermatomyositis patients

Background

Anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis (anti-MDA5+DM) patients are associated with considerable mortality, and opportunistic infections including Pneumocystis jirovecii pneumonia (PJP)is the main cause. This study was to identify clinical characteristics, risk factors, and prognostic factors of PJP diagnosed by bronchoalveolar lavage fluid (BALF) metagenomic next-generation sequencing (mNGS) in anti-MDA5+ DM patients.

Methods

In this retrospective observational study, all patients admitted with suspected pneumonia were detected for mNGS in BALF. The demographics, comorbidities, laboratory parameters, and treatments of the patients were compared and analyzed in both groups to identify the potential risk factors for PJP and death via Logistic regression and Cox proportional hazards regression, respectively.

Results

Overall, 92 patients were included in this study, 46(50.0%) were defined as PJP+ group, and the other 46 (50.0%) as PJP- group, and 31(67.4%) PJP occurred in the first 3 months. Increased neutrophil-lymphocyte ratio (NLR) and CRP were independent risk factors for PJP occurrence, while trimethoprim-sulfamethoxazole (TMP/SMZ) prophylaxis was an independent protective factor (all p<0.05). The three-months mortality rate was higher in the PJP+ group compared to PJP- group (43.5% vs 23.9%, p=0.047). Rapidly progressive interstitial lung disease (RPILD) was a main predictor of mortality in anti-MDA5+DM patients with PJP, whereas glucocorticoid use was a significant protective factor.

Conclusions

PJP has high prevalence and mortality in anti-MDA5+DM, while TMP/SMZ prophylaxis significantly reduces PJP risk. Mortality in PJP+ patients is primarily concentrated within the first 3 months, associated with RPILD. Early intervention with corticosteroids and prophylactic measures are crucial in reducing mortality.

Atypical presentation of anti-small ubiquitin-like modifier 1 and melanoma differentiation-associated gene 5 antibody positive dermatomyositis presenting with significant inflammatory myopathy on biopsy and normal creatine kinase levels: A case report

Idiopathic inflammatory myopathies are characterized by chronic inflammation of skeletal muscle. The main subtypes of idiopathic inflammatory myopathies include dermatomyositis, polymyositis, and necrotizing autoimmune myopathies. Dermatomyositis is characterized by symmetrical proximal muscle weakness, distinctive skin lesions, and systemic manifestations. Dermatomyositis commonly presents with elevated creatinine kinase levels. However, we report a case of a 19-year-old female presenting with dermatomyositis positive for anti-small ubiquitin-like modifier 1 and melanoma differentiation-associated gene 5 antibodies presenting with classic signs and symptoms like progressive proximal muscle weakness, dysphagia, hyperpigmented rash, and Gottron's papules but had severe inflammatory myopathy on muscle biopsy and normal creatinine kinase levels. This case emphasizes an atypical presentation of dermatomyositis where she did not have amyopathic dermatomyositis despite having a positive anti-melanoma differentiation-associated gene 5 antibody and normal creatinine kinase. This underscores the importance of history and physical examination despite contradictory laboratory results.

Anti-MDA5 positivity: describing the frequency and spectrum of clinically evident MDA5 disease

To evaluate experience in a tertiary rheumatology service with melanoma differentiation-association-protein-5 (MDA5) disease and testing, patients with positive autoantibody results were reviewed for the presence of clinical disease. Anti-MDA5 positivity was detected in 2% of myositis-specific antibody tests. Of these, 29% did not have features consistent with anti-MDA5 disease. However, when present, MDA5 disease is severe with a high mortality.

Myositis-specific and myositis-associated autoantibodies: their clinical characteristics and potential pathogenic roles

In recent years, various myositis-specific and myositis-associated autoantibodies have been identified in idiopathic inflammatory myopathies, including dermatomyositis (DM), anti-synthetase syndrome (ASS), immune-mediated necrotizing myopathy (IMNM), and inclusion body myositis (IBM). These autoantibodies exhibit unique characteristics in terms of organ involvement, severity, and treatment response, making their understanding crucial for accurate diagnosis and effective therapy. This review provides a comprehensive overview of the clinical features of recently discovered myositis-specific and associated autoantibodies, while exploring their potential roles in the pathogenesis and exacerbation of myositis. Key findings include the production of anti-TIF1γ antibodies in model mice, the upregulation of Mi2-related genes in anti-Mi2 antibody-positive dermatomyositis muscle tissue, and Jo-1 antigen-induced T cell activation, shedding light on whether disease mechanisms are driven by autoantibodies or autoantigens.

Autoantibodies to nuclear valosin-containing protein-like protein: systemic sclerosis-specific antibodies revealed by in vitro human proteome

OBJECTIVES

To identify and characterize undescribed systemic sclerosis (SSc)-specific autoantibodies targeting nucleolar antigens and to assess their clinical significance.

METHODS

We conducted proteome-wide autoantibody screening (PWAS) against serum samples from SSc patients with nucleolar patterned anti-nuclear antibodies (NUC-ANAs) of specific antibodies (Abs) unknown, utilizing wet protein arrays fabricated from in vitro human proteome. Controls included SSc patients with already-known SSc-specific autoantibodies, patients with other connective tissue diseases and healthy subjects. The selection of nucleolar antigens was performed by database search in the Human Protein Atlas. The presence of autoantibodies was certified by immunoblots and immunoprecipitations. Indirect immunofluorescence assays on HEp-2 cells were also conducted. Clinical assessment was conducted by retrospective review of electronic medical records.

RESULTS

PWAS identified three candidate autoantibodies, including anti-nuclear valosin-containing protein-like (NVL) Ab. Additional measurements in disease controls revealed that only anti-NVL Abs are exclusively detected in SSc. Detection of anti-NVL Abs was reproduced by conventional assays such as immunoblotting and immunoprecipitation. Indirect immunofluorescence assays demonstrated homogeneous nucleolar patterns. Anti-NVL Ab-positive cases were characterized by significantly low prevalence of diffuse skin sclerosis and interstitial lung disease, compared with SSc cases with NUC-ANAs other than anti-NVL Abs, such as anti-U3-RNP and anti-Th/To Abs.

CONCLUSION

Anti-NVL Ab is an SSc-specific autoantibody associated with a unique combination of clinical features, including limited skin sclerosis and lack of lung involvement.

Clinically amyopathic dermatomyositis: Clinical, laboratory, and histopathological features

BACKGROUND

Despite the advancements in the categorization of clinically amyopathic dermatomyositis (CADM), the classification and diagnosis of its subtypes are still challenging. The aim of our study was to describe the clinicopathological features of CADM and assess the differences between amyopathic dermatomyositis (ADM) and hypomyopathic dermatomyositis (HDM).

METHODS

This retrospective study included 43 patients with CADM diagnosed at our institution from 2016 to 2020. Patients were subclassed into ADM (n = 30) and HDM (n = 13) groups to assess their clinicopathological differences.

RESULTS

All included patients had characteristic cutaneous manifestations of dermatomyositis; 67.4% had myositis-associated auto-antibodies, including ANA (32.6%), RNP (14.0%), anti-Ro52 (9.3%), anti-p155/140 (7.0%), rheumatoid factor (7.0%), anti-NXP-2 (4.7%), anti-MDA5 (2.3%), and anti-Jo-1 (2.3%) antibodies. One patient had associated interstitial lung disease, and another patient had oral squamous cell carcinoma. The histopathological findings included mucin deposition (69.8%), telangiectasia (65.1%), lymphocytic infiltrate (48.8%), vacuolar interface dermatitis (46.5%), and epidermal atrophy (14.0%). Compared to patients with HDM, ADM patients were significantly less likely to have epidermal atrophy, 3.3% versus 38.5% (p = 0.006), and more likely to have mucin deposition, 80.0% versus 46.2% (p = 0.028).

CONCLUSION

We described the clinicopathological features of CADM and highlighted the distinctions between ADM and HDM dermatopathologic findings. This information may prove helpful in diagnosing ambiguous lesions.

Comparison of Lineblot and Immunoprecipitation Methods in the Detection of Myositis-Specific and Myositis-Associated Antibodies in Patients with Idiopathic Inflammatory Myopathies: Consistency with Clinical Diagnoses

Background: the reference method for detection of myositis-specific and myositis-associated antibodies (MSAs and MAAs) is considered immunoprecipitation (IP), but it is routinely replaced by semi-automated methods, like lineblot (LB). Few data are available on the consistency with clinical diagnoses; thus, we aim at analysing these aspects. Methods: sixty-nine patients with idiopathic inflammatory myopathies (IIM) were studied via LB (Myositis Antigens Profile 3 EUROLINE, Euroimmun) and IP (RNA and protein antigens). The degree of concordance between methods was calculated using Cohen's coefficient. Results: a substantial concordance was found for anti-Ku and anti-PM/Scl and a moderate concordance was found for anti-Jo1 and anti-Mi-2, while a fair concordance was found for anti-EJ, anti-SRP, and anti-Ro52 antibodies. The concordance could not be calculated for anti-OJ, anti-PL-7, anti-PL-12, anti-NXP2, anti-TIF1ɣ, and anti-MDA5, because they were only detected with one method. Multiple MSAs were found only with LB in 2/69 sera. Anti-MDA5, TIF1ɣ, NXP2 (detected via IP), and anti-Jo1 in anti-synthetase syndrome (both LB and IP) had the best concordance with clinical diagnosis. Conclusions: LB and IP show substantial concordance for PM/Scl and Ku, and moderate concordance for Jo1 and Mi-2, with a good concordance with clinical diagnoses. IP shows a high performance for DM-associated MSAs. LB seems to be more sensitive in detecting anti-Ro52 antibodies, but it identified multiple MSAs, unlike IP.

Profile of patients with Juvenile Dermatomyositis and Anti-MDA5 autoantibodies

BACKGROUND

Anti-MDA5 autoantibody-positive dermatomyositis (MDA5-DM) is associated with clinically amyopathic forms and rapidly progressive interstitial lung disease (ILD); however, data in children are limited. In this study, we described our cohort of anti-MDA5-positive juvenile DM (MDA5-JDM) from a tertiary care center in North India.

METHODS

We performed a retrospective analysis of children with MDA5-JDM who were diagnosed and followed up at our center and compared them with our anti-MDA5-negative cohort. We also compared the published literature on MDA5-DM with the juvenile cohort.

RESULTS

Of 66 children with JDM who underwent testing for MSA, 10(15.5%) had anti-MDA5 positivity. The mean age at onset of clinical manifestations was 8.4 years; male: female ratio was 7:3. Five of nine patients who underwent screening HRCT chest had ILD; one amongst them had a fatal rapidly progressive disease. Children with MDA5-JDM had significantly more arthralgia/arthritis (p = 0.006) and ILD (p = 0.0005) compared to anti-MDA5 negative JDM in our cohort. While MDA5-DM had high rates of Raynaud's phenomenon (p = 0.04) and pulmonary involvement (p = 0.001), juvenile patients had a higher prevalence of constitutional symptoms (p = 0.01), skin manifestations (p = 0.003), arthritis (p = 0.001), and muscle weakness (p = 0.001).

CONCLUSIONS

Arthritis and ILD are commonly seen with MDA5-JDM; however, the frequency of ILD and clinically amyopathic forms are less common compared to adult counterparts.

IMPACT

The frequency of anti-MDA5 antibodies in a North Indian cohort of JDM is much lower (15.5%) compared to adult studies in dermatomyositis from Southeast Asia (~25%). Incidence of interstitial lung disease (ILD) and arthritis is high in anti-MDA5 autoantibody-positive JDM. Rates of a rapidly progressive form of ILD and clinically amyopathic dermatomyositis are much lower in children compared to adults with anti-MDA5-associated dermatomyositis.

Anti MDA-5 associated rapidly progressive interstitial lung disease complicated by viral pneumonia - a fatal outcome

Dermatomyositis is a heterogeneous systemic disease, with 7% to 10% of the individuals presenting the Anti MDA-5 antibody. This subset of patients has clinically amyotropic dermatomyositis, presenting with cutaneous ulcer and rapidly progressive interstitial lung disease. We report the case of a 22-year-old male with a six-month history of low-grade fever associated with myalgia, polyarthralgia, and marked weight loss. He had a history of shortness of breath and high-grade fever 15 days before admission. His clinical features and imaging workup were consistent with acute respiratory distress syndrome. A nasal swab was positive for H1N1 influenza virus infection. During the disease investigation, he succumbed after nine days of admission. The autopsy examination showed diffuse alveolar damage on a background of non-specific interstitial pattern of injury in the lungs. His postmortem muscle biopsy revealed subtle changes of inflammatory myopathy. The brain showed diffuse subarachnoid hemorrhage. Evaluation of postmortem serum sample revealed positivity for Anti MDA-5 and Ro-52 antibodies. This was a case of Anti MDA-5 and Ro-52 associated dermatomyositis with non-specific interstitial pneumonia pattern of lung injury complicated with H1N1 influenza pneumonia, leading to diffuse alveolar damage and subsequent respiratory failure and death. Serum Anti MDA-5 antibodies represent an important biomarker for diagnosing and predicting prognosis for patients with idiopathic inflammatory myopathies, especially clinically amyopathic dermatomyositis. Anti-Ro-52 has been reported in a wide variety of autoimmune diseases, particularly in myositis, scleroderma, and autoimmune liver diseases. Ro-52 autoantibodies are associated with interstitial lung disease (ILD), and their presence should encourage the clinician's curiosity to search for ILD.

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

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

Examination of prognostic factors in anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis

OBJECTIVE

This study investigated the prognostic factors of anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis (MDA5-DM).

METHODS

This study analysed 34 MDA5-DM cases (20 and 14 in the survival and death groups, respectively) encountered at Kurume University between 2008 and 2021. The clinical, physiological, and computed tomography findings, pulmonary function, and serological results were retrospectively evaluated for each MDA5-DM case during the first visit and throughout the next 12 weeks.

RESULTS

In the death group, the mean age of patients was higher (47.6 vs. 61.8 years), while the duration from symptom onset to consultation was shorter (110 vs. 34.9 days). During the first visit, the death group demonstrated a significantly higher serum C-reactive protein level (0.52 vs. 1.99) and a significantly lower albumin level (3.23 vs. 2.63) than the survival group; this persisted throughout the next 12 weeks. Poor prognosis was associated with C-reactive protein and albumin levels >0.19 mg/dl and <2.3 g/dl, respectively, 4 weeks after starting the treatment.

CONCLUSION

Four weeks after starting the treatment, serum C-reactive protein and albumin levels of patients with MDA5-DM can be used to evaluate treatment response and predict prognosis.

Soluble CXCL16 is a prognostic biomarker associated with rapidly progressive interstitial lung disease complicated with dermatomyositis

OBJECTIVES

Rapidly progressive interstitial lung disease (RPILD) in patients with dermatomyositis (DM) significantly impacts prognosis, leading to high mortality rates. Although several indicators have been demonstrated to strongly correlate with the risk of developing RPILD, their clinical utility still needs to be investigated. The objective of this study was to investigate the clinical significance of soluble CXCL16 (sCXCL16) in DM patients complicated with RPILD.

METHODS

Serum sCXCL16 was measured by enzyme-linked immunosorbent assay in 96 patients with DM and 55 matching healthy donors. Correlations between sCXCL16 levels and clinical features, laboratory examinations and the predictive value of baseline sCXCL16 level for RPILD were analysed.

RESULTS

The serum sCXCL16 levels were significantly higher in patients with DM (n = 96, 3.264 ± 1.516 ng/mL) compared with healthy donors (n = 55, 1.781 ± 0.318 ng/mL), especially in DM complicated with RPILD (n = 31, 4.441 ± 1.706 ng/mL). The sCXCL16 levels were positively correlated with levels of serum ferritin, C reactive protein, erythrocyte sedimentation rate, lactate dehydrogenase, hydroxybutyrate dehydrogenase, and negatively correlated with peripheral lymphocytes percentage, but showed no correlation with levels of anti-melanoma differentiation-associated gene 5 antibody, Krebs von den Lungen-6 or creatine kinase. Multivariable analysis showed that elevated sCXCL16 was an independent prognostic factor for poor prognosis of RPILD in patients with DM. The 2-year survival rate was significantly lower in patients with high sCXCL16 level than in those with low sCXCL16 level.

CONCLUSION

A higher serum sCXCL16 level was identified as a predictive biomarker of RPILD in patients with DM, and closely associated with poor prognosis.

Single-cell landscape of peripheral immune response in patients with anti-melanoma differentiation-associated gene 5 dermatomyositis

OBJECTIVE

Anti-melanoma differentiation-associated gene 5 (Anti-MDA5)-positive DM is a rare but life-threatening autoimmune disorder that is associated with a high risk of developing rapidly progressive interstitial lung disease. Current empirical therapies offer limited benefit in terms of patient survival, as little is known about the aetiology of anti-MDA5 DM. To best understand its immune landscape, we applied single-cell RNA sequencing (scRNA-seq) to peripheral blood samples from DM patients and healthy controls.

METHODS

Peripheral blood mononuclear cells (PBMCs) from eight DM patients (including three distinct subtypes of DM) and two healthy donors were sequenced using the 10X Genomics platform. Additional scRNA-seq data for four healthy donors were incorporated for further bioinformatic analysis.

RESULTS

Aberrantly increased proportions of CD14+ monocytes and plasma cells were observed in anti-MDA5 DM PBMC samples. Moreover, we found an overactivated type I IFN response and antiviral immunity in both innate and adaptive immune cells derived from anti-MDA5 DM patients that was positively correlated with disease severity. Importantly, a unique subset of CD14+ monocytes that highly expressed IFN alpha-inducible protein 27 (IFI27), a biomarker for viral infection, and IFN induced with helicase C domain 1 (IFIH1, which encodes MDA5) was specifically identified in anti-MDA5 DM samples for the first time.

CONCLUSION

Our study has illustrated the peripheral immune cell atlas of a number of DM subtypes, has provided compelling evidence for a viral infection-derived origin for anti-MDA5 DM, and has indicated potential targets for innovative therapeutic interventions.

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

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

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.

Anti-melanoma Differentiation-Associated Gene 5 (Anti-MDA5) Dermatomyositis-Associated Interstitial Lung Disease Complicated by Pneumomediastinum: A Case Report and Literature Review

Anti-melanoma differentiation-associated gene 5 (anti-MDA5) dermatomyositis (DM) is a subset of amyopathic myositis and is associated with unique cutaneous manifestations and rapidly progressive interstitial lung disease (RP-ILD). A rare complication associated with high mortality is the occurrence of pneumomediastinum. We present a case of a 58-year-old female with anti-MDA5 DM-associated interstitial lung disease (ILD) complicated by pneumomediastinum. Treatment with pulse dose steroids and intravenous cyclophosphamide led to clinical improvement and resolution of the pneumomediastinum. Our case emphasizes the recognition of ILD-associated pneumomediastinum in patients with anti-MDA5 DM. Swift diagnosis and aggressive treatment are crucial due to the associated high mortality.

Soluble form of the MDA5 protein in human sera

Viral double-stranded RNA (dsRNA) is sensed by toll-like receptor 3 (TLR3) and retinoic acid-inducible gene I (RIG-I)-like receptors (RLRs), including melanoma differentiation-associated gene 5 (MDA5). MDA5 recognizes the genome of dsRNA viruses and replication intermediates of single-stranded RNA viruses. MDA5 also plays an important role in the development of autoimmune diseases, such as Aicardi-Goutieres syndrome and type I diabetes. Patients with dermatomyositis with serum MDA5 autoantibodies (anti-CADM-140) are known to have a high risk of developing rapidly progressive interstitial lung disease and poor prognosis. However, there have been no reports on the soluble form of MDA5 in human serum. In the present study, we generated in-house monoclonal antibodies (mAbs) against human MDA5. We then performed immunohistochemical analysis and sensitive sandwich immunoassays to detect the MDA5 protein using two different mAbs (clones H27 and H46). As per the immunohistochemical analysis, the MDA5 protein was moderately expressed in the alveolar epithelia of normal lungs and was strongly expressed in the cytoplasm of lymphoid cells in the tonsils and acinar cells of the pancreas. Interestingly, soluble MDA5 protein was detectable in the serum, but not in the urine, of healthy donors. Soluble MDA5 protein was also detectable in the serum of patients with dermatomyositis. Immunoblot analysis showed that human cells expressed a 120 kDa MDA5 protein, while the 60 kDa MDA5 protein increased in the supernatant of peripheral mononuclear cells within 15 min after MDA5 agonist/double-strand RNA stimulation. Hydrogen deuterium exchange mass spectrometry revealed that an anti-MDA5 mAb (clone H46) bound to the epitope (415QILENSLLNL424) derived from the helicase domain of MDA5. These results indicate that a soluble MDA5 protein containing the helicase domain of MDA5 could be rapidly released from the cytoplasm of tissues after RNA stimulation.

MDA5-autoimmunity and interstitial pneumonitis contemporaneous with the COVID-19 pandemic (MIP-C)

BACKGROUND

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

METHODS

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

FINDINGS

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

INTERPRETATION

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

FUNDING

This work was supported in part by the National Institute for Health Research (NIHR) Leeds Biomedical Research Centre (BRC), and in part by the National Institutes of Health (NIH) grant R01-AI155696 and pilot awards from the UC Office of the President (UCOP)-RGPO (R00RG2628, R00RG2642 and R01RG3780) to P.G. S.S was supported in part by R01-AI141630 (to P.G) and in part through funds from the American Association of Immunologists (AAI) Intersect Fellowship Program for Computational Scientists and Immunologists.

Two challenging cases of anti-MDA-5 dermatomyositis with rapidly progressive interstitial lung disease

Anti-MDA-5 dermatomyositis (DM) is a subtype of idiopathic inflammatory myopathy, commonly presenting as clinically amyopathic dermatomyositis. It is associated with rapidly progressive interstitial lung disease and a poor prognosis. Here, we present two cases of anti-MDA-5 DM and discuss the challenges associated with timely diagnosis, and the importance of early and aggressive treatment.

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.

Pathogenic role and clinical significance of neutrophils and neutrophil extracellular traps in idiopathic inflammatory myopathies

Idiopathic inflammatory myopathies (IIM) are a heterogeneous group of chronic autoimmune diseases characterized by muscle damage and extramuscular symptoms, including specific skin rash, arthritis, interstitial lung disease, and cardiac involvement. While the etiology and pathogenesis of IIM are not yet fully understood, emerging evidence suggests that neutrophils and neutrophil extracellular traps (NETs) have a role in the pathogenesis. Recent research has identified increased levels of circulating and tissue neutrophils as well as NETs in patients with IIM; these contribute to the activation of the type I and type II interferons pathway. During active IIM disease, myositis-specific antibodies are associated with the formation and incomplete degradation of NETs, leading to damage in the lungs, muscles, and blood vessels of patients. This review focuses on the pathogenic role and clinical significance of neutrophils and NETs in IIM, and it includes a discussion of potential targeted treatment strategies.

Autoantibodies against the melanoma differentiation-associated protein 5 in patients with dermatomyositis target the helicase domains

OBJECTIVES

Clinical observations in patients with dermatomyositis (DM) and autoantibodies against the melanoma differentiation-associated protein 5 (MDA5) suggest that the autoantibodies contribute to the pathogenesis of MDA5(+) DM. To gain insight into the role of the anti-MDA5 autoantibodies, we aimed to identify their binding sites on the different domains of the MDA5 protein.

METHODS

We developed an in-house ELISA to assess the reactivity against the MDA5 domains (conformational epitopes) in plasma (n = 8) and serum (n = 24) samples from MDA5(+) patients with varying clinical manifestations and disease outcomes. The reactivities were also assessed using western blot (linearized epitopes). An ELISA-based depletion assay was developed to assess cross-reactivity among the different MDA5 domains.

RESULTS

All eight plasma samples consistently showed reactivity towards conformational and linearized epitopes on the helicase domains of the MDA5 protein. The ELISA-based depletion assay suggests that anti-MDA5 autoantibodies specifically target each of the three helicase domains. Twenty-two of the 24 serum samples showed reactivity in the in-house ELISA and all 22 displayed reactivity towards the helicase domains of the MDA5 protein.

CONCLUSIONS

Our data revealed that the main immunogenic targets of anti-MDA5 autoantibodies from MDA5(+) patients are the helicase domains. Considering that the helicase domains are responsible for the enzymatic activity and subsequent triggering of an inflammatory response, our findings suggest that binding of anti-MDA5 autoantibodies could alter the canonical activity of the MDA5 protein and potentially affect the downstream induction of a pro-inflammatory cascade.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Elevated serum B-cell activator factor levels predict rapid progressive interstitial lung disease in anti-melanoma differentiation associated protein 5 antibody positive dermatomyositis

BACKGROUND

Rapid progressive interstitial lung disease (RP-ILD) is the leading cause of anti-melanoma differentiation associated protein 5 antibody positive dermatomyositis (anti-MDA5+DM) related death. Elevated serum B-cell activating factor (BAFF) levels have been implicated in connective tissue diseases associated ILD. Here, we evaluate whether BAFF could be a prognostic biomarker for predicting RP-ILD in anti-MDA5+DM patients.

METHODS

Serums were collected from 39 patients with anti-MDA5+DM (20 with RP-ILD and 19 with non-RP-ILD), 20 antisynthase syndrome (ASS) patients and 20 healthy controls (HC). BAFF concentration was measured by an enzyme-linked immunosorbent assay.

RESULTS

Serum BAFF level was higher in anti-MDA5+DM patients than those in ASS patients and HC (3882.32 ± 1880.09 vs. 2540.89 ± 1403.04 and 2486.28 ± 767.97 pg/mL, p = 0.0056 and 0.0038, respectively). Within anti-MDA5+DM groups, RP-ILD patients exhibited higher BAFF concentration than non-RP-ILD group (4549.78 ± 1839.97 vs. 3297.28 ± 1794.69 pg/mL, p = 0.04). The BAFF concentration was positively correlated with levels of C-reactive protein (CRP), dehydrogenase (LDH) and cytokeratin (CK) in anti-MDA5+DM patients (r = 0.350, p = 0.035; r = 0.393, p = 0.016; r = 0.518, p = 0.001; respectively). The best cut-off value of BAFF concentration was 2971.5 pg/mL by ROC curve (AUC area = 0.690, p = 0.045) and BAFF > 2971.5 pg/mL was an independent risk factor for RP-ILD using multivariate analysis (OR = 9.389, 95% CI = 1.609-54.769; p = 0.013).

CONCLUSIONS

Serum BAFF could be a useful prognostic biomarker for early detecting RP-ILD risk in anti-MDA5+DM patients.

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.

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.

Treatment of myopathy and cutaneous ulcers in anti-MDA5-positive dermatomyositis with triple therapy

Antimelanoma differentiation-associated protein 5 positive dermatomyositis (MDA5 DM) is a rare subtype of idiopathic inflammatory myopathy. There are limited data available regarding the cutaneous manifestations of MDA5 DM in the African American population. We presented the case of a male patient in his early 20s who presented with debilitating cutaneous ulceration and myopathy. Workup revealed interstitial lung disease (ILD) and positive MDA5 serology consistent with MDA5 DM. He made a remarkable recovery in terms of myopathy and cutaneous ulcerations with a multipronged regimen of prednisone, intravenous immunoglobulin and mycophenolate mofetil. However, there was a progression of ILD on this regimen which warranted use of rituximab.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

KEY POINTS

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

A bibliometric analysis of the research status and trends in studies on polymyositis and dermatomyositis with interstitial lung disease from 2000 to 2022 using Web of Science

BACKGROUND

The main subtypes of idiopathic inflammatory myopathies (IIMs)-polymyositis (PM) and dermatomyositis (DM)-are often presented as interstitial lung disease (ILD) in clinical practice; therefore, many researchers have combined the three studies into PM/DM with ILD.

METHODS

Using bibliometrics, the research status, progress, and hotspots of PM/DM with ILD between 2000 and 2022 were studied. Literature data on PM/DM with ILD were retrieved from the Web of Science (WoS) database for the research period. Visualization software, including VOSviewer, Pajek, CiteSpace, and Scimago Graphica were used for bibliometric analysis.

RESULTS

A total of 1555 relevant articles were obtained, and the overall research in this field showed an increasing trend. Regarding contributing countries and venues, Japan published the most articles while Rheumatology was the most prolific journal. Regarding authors, the most published article was by Wang Guochun from Changchun University of Technology in China. Keyword analysis and cocited literature cluster analysis showed that diagnosis, classification, autoantibodies, antibodies, prognosis, complications, and treatment of PM/DM with ILD have been hot topics in this field recently. Moreover, our study shows that anti-mda5 antibody, mortality, gene 5 antibody, IIMs, double-blind, and prognostic factors, among others, may be new hot topics.

CONCLUSION

This study found that research on PM/DM with ILD has increased over time, and scholars are paying more attention to this field. The development of new drugs for the management, treatment, and prevention of PM/DM with ILD is the primary task of researchers and a direction for future research in this field.

Rapidly progressive interstitial lung disease risk prediction in anti-MDA5 positive dermatomyositis: the CROSS model

Background

The prognosis of anti-melanoma differentiation-associated gene 5 positive dermatomyositis (anti-MDA5+DM) is poor and heterogeneous. Rapidly progressive interstitial lung disease (RP-ILD) is these patients' leading cause of death. We sought to develop prediction models for RP-ILD risk in anti-MDA5+DM patients.

Methods

Patients with anti-MDA5+DM were enrolled in two cohorts: 170 patients from the southern region of Jiangsu province (discovery cohort) and 85 patients from the northern region of Jiangsu province (validation cohort). Cox proportional hazards models were used to identify risk factors of RP-ILD. RP-ILD risk prediction models were developed and validated by testing every independent prognostic risk factor derived from the Cox model.

Results

There are no significant differences in baseline clinical parameters and prognosis between discovery and validation cohorts. Among all 255 anti-MDA5+DM patients, with a median follow-up of 12 months, the incidence of RP-ILD was 36.86%. Using the discovery cohort, four variables were included in the final risk prediction model for RP-ILD: C-reactive protein (CRP) levels, anti-Ro52 antibody positivity, short disease duration, and male sex. A point scoring system was used to classify anti-MDA5+DM patients into moderate, high, and very high risk of RP-ILD. After one-year follow-up, the incidence of RP-ILD in the very high risk group was 71.3% and 85.71%, significantly higher than those in the high-risk group (35.19%, 41.69%) and moderate-risk group (9.54%, 6.67%) in both cohorts.

Conclusions

The CROSS model is an easy-to-use prediction classification system for RP-ILD risk in anti-MDA5+DM patients. It has great application prospect in disease management.

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.

Case report: Checkpoint inhibitor pneumonitis with positive anti-melanoma differentiation-associated gene 5 antibodies in a patient with lung cancer

With the widespread use of immune checkpoint inhibitors to treat various cancers, pulmonary toxicity has become a topic of increasing concern. Anti-melanoma differentiation-associated gene 5 (anti-MDA5) antibodies are strongly associated with rapidly progressive interstitial lung disease (RP-ILD) in patients with clinically amyopathic dermatomyositis. However, anti-MDA5 antibody expression has not been reported in patients with immune-related adverse events. We present the case of a 74-year-old man with lung adenocarcinoma who developed RP-ILD after treatment with immune checkpoint inhibitors. Further investigation revealed multiple autoantibodies, including anti-MDA5 antibodies. He initially responded to systemic glucocorticoids, immunosuppressants, and tocilizumab but eventually died from worsening pneumomediastinum. This case is the first one to suggest that checkpoint inhibitor pneumonitis can present as RP-ILD with positive anti-MDA5 antibodies, which may be predictive of a poor prognosis.