Utility of anti-melanoma differentiation-associated gene 5 antibody measurement in identifying patients with dermatomyositis and a high risk for developing rapidly progressive interstitial lung disease: a review of the literature and a meta-analysis

Autoantibodies Associated With Connective Tissue Diseases: What Meaning for Clinicians?

Connective tissue diseases (CTDs) such as systemic lupus erythematosus, systemic sclerosis, myositis, Sjögren's syndrome, and rheumatoid arthritis are systemic diseases which are often associated with a challenge in diagnosis. Autoantibodies (AAbs) can be detected in these diseases and help clinicians in their diagnosis. Actually, pathophysiology of these diseases is associated with the presence of antinuclear antibodies. In the last decades, many new antibodies were discovered, but their implication in pathogenesis of CTDs remains unclear. Furthermore, the classification of these AAbs is nowadays misused, as their targets can be localized outside of the nuclear compartment. Interestingly, in most cases, each antibody is associated with a specific phenotype in CTDs and therefore help in better defining either the disease subtypes or diseases activity and outcome. Because of recent progresses in their detection and in the comprehension of their pathogenesis implication in CTD-associated antibodies, clinicians should pay attention to the presence of these different AAbs to improve patient's management. In this review, we propose to focus on the different phenotypes and features associated with each autoantibody used in clinical practice in those CTDs.

Rapidly progressive interstitial lung disease due to anti-MDA5 antibodies without skin involvement: a case report and literature review

Anti-MDA5 antibodies have been strongly associated with rapidly progressive interstitial lung disease (RP-ILD) in dermatomyositis (DM) patients, especially in the clinically amyopathic subset (CADM). We present a case of anti-MDA5 antibody-associated RP-ILD in a patient with arthritis but with no other clinical signs suggestive of DM or CADM successfully treated with a combination of cyclophosphamide, cyclosporine and corticoids. A review of the literature was also done. Despite its rarity, anti-MDA5 antibody-associated ILD should be suspected in cases of RP-ILD even without other signs of DM or CADM as prompt and aggressive treatment could improve prognosis.

Distinctive cutaneous and systemic features associated with specific antimyositis antibodies in adults with dermatomyositis: a prospective multicentric study of 117 patients

BACKGROUND

Identification of myositis-specific autoantibodies (MSAs) for dermatomyositis (DM) could allow the characterization of an antibody-associated clinical phenotype.

OBJECTIVE

We sought to define the clinical phenotype of DM and the risk of cancer, interstitial lung disease (ILD) and calcinosis based on MSA.

METHODS

A 3.5-year multicentre prospective study of adult DM patients was conducted to determine the clinical phenotype associated with MSAs and the presence of cancer, ILD and calcinosis.

RESULTS

MSAs were detected in 47.1% of 117 included patients. Patients with antimelanoma differentiation-associated protein-5 antibodies (13.7%) had significantly more palmar violaceous macules/papules [odds ratio (OR) 9.9], mechanic's hands (OR 8), cutaneous necrosis (OR 3.2), articular involvement (OR 15.2) and a higher risk of ILD (OR 25.3). Patients with antitranscriptional intermediary factor-1 antibodies (11.1%), antinuclear matrix protein-2 antibodies (6.8%) and antiaminoacyl-transfer RNA synthetase (5.1%) had, respectively, significantly more poikiloderma (OR 5.9), calcinosis (OR 9.8) and articular involvement (OR 15.2). Cutaneous necrosis was the only clinical manifestation significantly associated with cancer (OR 3.1).

CONCLUSION

Recognition of the adult DM phenotype associated with MSAs would allow more accurate appraisal of the risk of cancer, ILD and calcinosis.

Anti-melanoma differentiation-associated gene 5 (MDA5) dermatomyositis: A concise review with an emphasis on distinctive clinical features

Melanoma differentiation-associated gene 5 (MDA5) is a recently described autoantigen target in a subset of patients with dermatomyositis. Anti-MDA5 dermatomyositis is characterized by a unique mucocutaneous and systemic phenotype that includes cutaneous and oral ulceration, painful palmar papules, alopecia, panniculitis, arthritis, a lower incidence of myositis, and, importantly, an elevated risk of interstitial lung disease with a potentially fatal course. Because the clinical features can differ substantially from those typically observed in cutaneous dermatomyositis, the diagnosis is often overlooked, which might negatively affect patient outcomes. This review aims to familiarize the clinician with the distinctive clinical features of anti-MDA5 dermatomyositis in order to enhance its recognition and to facilitate an appropriate screening and management strategy.

Intravenous immunoglobulin contributes to the control of antimelanoma differentiation-associated protein 5 antibody-associated dermatomyositis with palmar violaceous macules/papules

Autoantibodies to melanoma differentiation-associated protein 5 (MDA5) are associated with a subset of patients with dermatomyositis (DM) who have rapidly progressive interstitial lung disease (RP-ILD) with poor prognosis. Intensive immunosuppressive therapy is initiated before irreversible lung damage can occur; however, there are few lines of evidence for the treatment of RP-ILD. Here, we report three cases of anti-MDA5 antibody-associated DM with RP-ILD in which the patients were treated with combined-modality therapy, including high-dose prednisolone, tacrolimus, intravenous cyclophosphamide and intravenous immunoglobulin (IVIG). In all three cases, serum ferritin levels, which are known to represent the disease activity of RP-ILD, were decreased after IVIG administration. IVIG might contribute to the control of the disease activity of anti-MDA5 antibody-positive DM. Moreover, palmar violaceous macules/papules around the interphalangeal joints, which was observed in all three cases in the incipient stage, might be a useful sign in suggesting a diagnosis of anti-MDA5 antibody-associated DM.

Neutrophil extracellular traps may contribute to interstitial lung disease associated with anti-MDA5 autoantibody positive dermatomyositis

In dermatomyositis (DM), anti-melanoma differentiation-associated gene 5 (MDA5) autoantibody (autoAb) marks a subtype with low grade or absent muscle inflammation but frequent and rapidly progressive interstitial lung disease (ILD). The pathogenesis of ILD remains poorly unknown. The aim of the study is to explore whether neutrophil extracellular traps (NETs) are involved in the development of ILD in DM patients with anti-MDA5 autoAb. Patients with clinically amyopathic dermatomyositis (CADM, n = 20), classic dermatomyositis (cDM, n = 30), polymyositis (PM, n = 20), and healthy controls (HC, n = 20) were enrolled. Anti-MDA5 autoantibody and Krebs von den Lungen-6 (KL-6) were detected by ELISA. Circulating levels of NETs were assessed by the quantification of both serum cell-free DNA (cfDNA) and LL-37 (cathelicidin LL-37). Immunofluorescent staining was used to visualize NETs ex vivo. The elevated circulating NETs level was detected in DM patients with ILD complication. Compared to anti-MDA5 Ab^- DM patients, anti-MDA5 Ab⁺ DM patients had the higher concentrations of serum cfDNA (293 ± 69 vs 252 ± 63 ng/ml; P = 0.035) and serum LL-37 (0.6 ± 1.0 vs 0.2 ± 0.2 ng/ml; P = 0.026). Positive correlations were established between serum levels of cfDNA and KL-6 in DM patients (r _s = 0.4422, P = 0.0003). anti-MDA5 Ab⁺ sera, other than anti-MDA5 Ab^- sera, could induce greater numbers of normal neutrophils to form NETs in vitro. These data suggest that aberrant NETs formation may be involved in the pathogenesis of ILD in DM patients with anti-MDA5 autoAb.

Anti-Melanoma Differentiation-Associated Gene 5 Is Associated With Rapidly Progressive Lung Disease and Poor Survival in US Patients With Amyopathic and Myopathic Dermatomyositis

OBJECTIVE

Clinically amyopathic dermatomyositis (CADM) is a subset of dermatomyositis (DM) presenting with the characteristic rash of DM without objective muscle weakness. Asian studies report that anti-melanoma differentiation-associated gene 5 (anti-MDA-5) autoantibody in CADM is associated with interstitial lung disease (ILD), particularly rapidly progressive ILD (RPILD). These associations have not been established in US myositis patients. The goal of our study was to determine the association of anti-MDA-5 autoantibody with ILD, RPILD, and survival in US patients with CADM and classic DM.

METHODS

CADM patients were identified in the University of Pittsburgh Myositis Center Database and matched 1:1 (sex and age) to classic DM controls. Anti-MDA-5 was measured by serum enzyme-linked immunosorbent assay. Kaplan-Meier, log rank, and chi-square tests were used for analysis.

RESULTS

We identified 61 CADM patients (62% women, mean age 48.2 years) and 61 classic DM controls (64% women, mean age 44.8 years). The frequencies of anti-MDA-5 positivity, ILD, and RPILD were similar in the 2 cohorts (MDA-5 positive: CADM 13.1% [8 of 61] and DM 13.1% [8 of 61], ILD positive: CADM 31.1% [19 of 61] and DM 26.2% [16 of 61], and RPILD positive: CADM 8.2% [5 of 61] and DM 5% [3 of 61]; P = 1, 0.55, and 0.46, respectively). Anti-MDA-5 positivity was significantly associated with ILD, since 50% of MDA-5-positive subjects (8 of 16) had ILD versus 25.5% of MDA-5-negative subjects (27 of 106; P = 0.04). Anti-MDA-5 was strongly associated with RPILD (P < 0.001). Anti-MDA-5-positive patients with ILD had worse baseline pulmonary function testing variables compared to anti-MDA-5-negative patients. Anti-MDA-5 positivity was significantly associated with poor survival (P = 0.007).

CONCLUSION

Anti-MDA-5 antibody is significantly associated with ILD, RPILD, worse pulmonary outcome, and survival in US classic DM and CADM patients.

HLA-DRB1 Alleles as Genetic Risk Factors for the Development of Anti-MDA5 Antibodies in Patients with Dermatomyositis

Objective.

Patients with polymyositis/dermatomyositis (PM/DM) who express anti-melanoma differentiation associated protein 5 (anti-MDA5) antibodies frequently present with interstitial lung disease (ILD). The aim of this study was to investigate the association of HLA-DRB1 with anti-MDA5 expression in PM/DM.

Methods.

The frequency of DRB1 alleles was compared among 70 patients with PM, 104 patients with DM, and 400 healthy controls in a Han Chinese population.

Results.

Frequencies of DRB1*04:01 [17.0% vs 1.3%, corrected p value (pc) = 3.8 × 10−8, OR 16.2, 95% CI 6.6–39.7] and *12:02 (42.6% vs 19.3%, pc = 0.008, OR 3.1, 95% CI 1.7–5.7) were significantly higher in anti-MDA5–positive patients with PM/DM compared with the controls. The frequencies of DRB1*04:01 (p = 5.2 × 10−6, OR 17.1, 95% CI 5.3–54.9) and *12:02 (p = 3.8 × 10−4, OR 3.1, 95% CI 1.7–5.7) in anti-MDA5–positive patients with DM-ILD were higher than in the controls, whereas the frequencies of DRB1*04:01 and *12:02 did not differ between the anti-MDA5–negative patients with DM-ILD and controls. No difference in the frequency of DRB1 alleles, other than *04:01, carrying the “shared epitope” (SE), i.e., *01:01, *01:02, *04:05, and *10:01, was observed between the controls and patients with DM stratified by the presence of anti-MDA5 and ILD.

Conclusion.

DRB1*04:01 and *12:02 confer susceptibility to anti-MDA5 antibody production in DM, which cannot be explained by the SE hypothesis.

Assessment of anti-MDA5 antibody as a diagnostic biomarker in patients with dermatomyositis-associated interstitial lung disease or rapidly progressive interstitial lung disease

Anti-melanoma differentiation-associated protein 5 (MDA5) antibody have been found in dermatomyositis (DM)-associated interstitial lung disease (DM-ILD) and DM-associated rapidly progressive ILD (DM-RPILD). Due to the conflicting results regarding the association between anti-MDA5 antibody and DM-ILD or DM-RPILD and the diagnostic value of this antibody for DM-ILD and DM-RPILD, we performed this meta-analysis. A systematic search was performed to identify studies published to January 14, 2017. Sixteen publications with 491 DM with ILD versus 605 DM without ILD, as well as eighteen publications with 186 DM with RPILD and 790 DM without RPILD were included. The pooled sensitivity, specificity, and area under the curve (AUC) values of anti-MDA5 antibody for DM-ILD were 0.47 (95% CI: 0.37-0.57), 0.96 (95% CI, 0.92-0.97), and 0.90 (95% CI: 0.88-0.93), respectively, with a low sensitivity value. The pooled sensitivity, specificity, and AUC values were 0.83 (95% CI: 0.77-0.88), 0.86 (95% CI: 0.80-0.91), and 0.87 (95% CI: 0.84-0.90) for DM with RPILD versus without RPILD with good sensitivity and specificity values. Trial sequential analysis showed sufficient evidence to support that anti-MDA5 antibody was associated with DM-ILD and DM-RPILD. The statistical power of this study calculated using G*Power version 3.1.9.2 was more than 99% (α = 0.05). Taken together, these findings suggest that anti-MDA5 antibody has a potential useful ability as a noninvasive biomarker in the diagnosis of RPILD in patients with DM.

Recent advances in connective tissue disease related interstitial lung disease

INTRODUCTION

Interstitial lung disease (ILD) is a common manifestation of connective tissue disease (CTD). Although the majority of patients with CTD-ILD are stable or slowly progressive, a significant group exhibits a more severe and progressive decline. Interstitial pneumonia with autoimmune features (IPAF) describes the subset of patients with interstitial pneumonia who have features suggesting underlying autoimmunity, but whose features fall short of a clear diagnosis of CTD. Areas covered: In this focused review, we discuss recent advances in early detection, prognostic evaluation, and management of autoimmune forms of ILD. Expert commentary: Early detection of ILD and a better understanding of factors that impact prognostication may be helpful when making decisions regarding therapeutic interventions. The treatment of CTD-ILD should be comprehensive, is often fraught with challenges and can be complicated by comorbid conditions and extra-thoracic disease activities. Several large randomized studies have examined the impact of immunosuppressive therapy for CTD-ILD, however, additional studies are needed to determine the optimal treatment strategies. Future studies may provide additional information about the best treatments in patients with IPAF.

Lung Manifestations in the Rheumatic Diseases

Lung ailments in rheumatic diseases present unique challenges for diagnosis and management and are a source of significant morbidity and mortality for patients. Unlike the idiopathic interstitial pneumonias, patients with rheumatic diseases experience lung disease in the context of a systemic disease that may make it more difficult to recognize and that may present greater risks with treatment. Despite recent advances in our awareness of these diseases, there is still a significant lack of understanding of natural history to elucidate which patients will have disease that is progressive and thus warrants treatment. What we do know is that a subset of patients with rheumatic disease experience parenchymal lung disease that can prognostically resemble idiopathic pulmonary fibrosis, such as in rheumatoid arthritis, and that others can have aggressive inflammatory lung disease in the context of autoimmune myositis, systemic sclerosis, or an undifferentiated autoimmune process. As we enter into a paradigm shift where we view lung health as a cornerstone of our care of patients with rheumatic diseases, we hopefully will improve our ability to identify those patients at highest risk for pulmonary disease and progression, and offer emerging treatments which will result in better outcomes and a better quality of life.

Cytokine profiles of amyopathic dermatomyositis with interstitial lung diseases treated with mycophenolate

A 59‐year‐old Japanese man diagnosed with interstitial lung disease associated with amyopathic dermatomyositis with anti‐melanoma differentiation‐associated gene 5 (MDA‐5) antibodies was treated with intravenous methyl prednisolone (PSL) 1000 mg, oral PSL 1 mg/kg, and oral cyclosporin 200 mg daily. His respiratory condition worsened after treatment with two times of intravenous cyclophosphamide and another steroid pulse therapy as well as PSL and cyclosporin. Addition of mycophenolate mofetil (MMF), 1.5 g daily improved PaO₂/FiO₂ (PF) ratio of the patient from 294 to 360 at 4 weeks and 416 at 15 weeks after addition of MMF. We measured cytokine concentration in preserved serum taken at 11 and 7 weeks before addition of MMF and at 4, 11, and 15 weeks after MMF administration. Of the 28 cytokines evaluated, the concentrations of fibroblast growth factors‐2 (FGF‐2), chemokine (C‐X3‐C motif) ligand 1 (CX3CL1), interleukin (IL)‐1ra, IL‐17A, inducible protein 10 (IP‐10), and monocyte chemotactic protein‐1 (MCP‐1) decreased after addition of MMF. These results suggest that MMF may be beneficial to patients with interstitial lung disease by modification of the cytokine/growth factor protein expression.

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

BACKGROUND

Antimelanoma differentiation-associated protein (anti-MDA)5 antibodies are associated with rapidly progressive interstitial lung disease (RP-ILD) in patients with clinically amyopathic dermatomyositis (CADM) or dermatomyositis (DM).

OBJECTIVES

We aimed to evaluate the relevance of monitoring anti-MDA5 antibody levels for the management of RP-ILD in patients with CADM or DM.

METHODS

Twelve patients with CADM (n = 10) or DM (n = 2) accompanied by RP-ILD were included. Baseline characteristics and outcomes were recorded. Serial measurements of anti-MDA5 antibody levels were measured. All patients were treated with corticosteroids, tacrolimus and intravenous cyclophosphamide.

RESULTS

All patients achieved RP-ILD remission after combined immunosuppressive therapy for a mean of 6·8 months, with significant decreases noted in the mean anti-MDA5 antibody levels at remission. Six (50%) patients became anti-MDA5 antibody negative after therapy. After a mean follow-up of 31 months, RP-ILD relapse was observed in four (33%) patients in both the anti-MDA5 antibody sustained positive group and the negative conversion group. However, relapsed patients in the sustained positive group relapsed earlier than those in the negative conversion group. Thus, a decrease in anti-MDA5 antibody levels during remission was associated with longer remission. Relapses were associated with a reincrease of anti-MDA5 antibody levels in four of four (100%) patients. In contrast, none of the patients without reincrease in anti-MDA5 antibody exhibited symptoms of relapse during follow-up. Therefore, reincrease in anti-MDA5 antibody levels was associated with relapse.

CONCLUSIONS

The anti-MDA5 antibody level is a novel parameter for monitoring and a good predictor of RP-ILD relapse in patients with CADM or DM.

Antimelanoma Differentiation-associated Gene 5 Antibody: Expanding the Clinical Spectrum in North American Patients with Dermatomyositis

Objective.

To determine the clinical features associated with the antimelanoma differentiation-associated gene 5 antibody (anti-MDA5) in US patients with clinically amyopathic dermatomyositis (CADM) and classic DM.

Methods.

Patients with CADM were consecutively selected from the University of Pittsburgh Myositis Database from 1985 to 2013. CADM was defined by a typical DM rash without objective muscle weakness and no or minimal abnormalities of muscle enzymes, electromyography, or muscle biopsy. DM was defined by Bohan and Peter criteria and was 1:1 matched (sex and age ± 5 yrs) to patients with CADM. Anti-MDA5 autoAb levels were determined using ELISA. Clinical features were compared between CADM and DM and between MDA5-positive and MDA5-negative subjects, using chi-squared and/or Mann-Whitney U tests as appropriate.

Results.

We identified 61 patients with CADM who were matched to 61 DM controls (female 62% vs 64%; mean age 44.8 yrs vs 48.2, p < 0.5). Anti-MDA5 frequency was the same in both cohorts (13.1%), and anti-MDA5 was significantly associated with a higher likelihood of cutaneous ulcers, digital tip ulcerations, and puffy fingers as well as interstitial lung disease (ILD). Most patients with ILD had rapidly progressive ILD (RPILD) leading to early death. Patients with CADM were more likely to have dysphagia, but there were no other clinical differences seen associated with CADM as compared to classic DM.

Conclusion.

Anti-MDA5 positivity had a similar frequency in US patients with CADM and DM and is associated with ILD, RPILD, cutaneous ulcers, digital tip ulceration, and poor survival.

Rapidly progressive interstitial lung disease due to anti-MDA-5 antibody-positive clinically amyopathic dermatomyositis complicated with cervical cancer: Successful treatment with direct hemoperfusion using polymyxin B-immobilized fiber column therapy

The anti-melanoma differentiation-associated gene 5 (MDA-5) antibody is a marker of clinically amyopathic dermatomyositis (CADM) and rapidly progressive interstitial lung disease (ILD) with acute respiratory failure. A 35-year-old woman with cervical cancer showed Gottron's papules, severe hypoxemia, and diffuse ground-glass opacities on chest computed tomography. She was diagnosed with rapidly progressive ILD associated with CADM. Her serum was positive for the anti-MDA-5 antibody. Combination therapy with corticosteroids, immunosuppressants, and direct hemoperfusion using polymyxin B-immobilized fiber column (PMX-DHP) improved her respiratory dysfunction. Eventually, surgery for the cancer was performed successfully. This is the first case to demonstrate the efficacy of PMX-DHP for rapidly progressive ILD with anti-MDA-5 antibody-positive CADM and a malignancy.

Anti-MDA5-Positive Dermatomyositis Presenting as Fever of Unknown Origin

Dermatomyositis is a chronic systemic autoimmune disease characterized by inflammatory infiltrates in the skin and muscle. The wide variability in clinical and serologic presentation poses a diagnostic challenge for the internist. Appreciation of the clinical variants of dermatomyositis allows for expedient diagnosis and avoidance of diagnostic error. We illustrate these challenges with the case of a 51-year-old Vietnamese-American man who initially presented with fever of unknown origin in the absence of overt skin and muscle manifestations. The diagnosis of dermatomyositis was not evident on several clinical encounters due to the absence of these hallmark symptoms. We review the variable clinical manifestations of a subtype of dermatomyositis associated with an autoantibody against melanoma differentiation-associated protein 5 (anti-MDA5) and suggest consideration of dermatomyositis as a diagnosis in patients presenting with systemic illness and markedly elevated ferritin, even in the absence of elevated muscle enzymes and classic autoantibodies.

The Diagnosis and Treatment of Antisynthetase Syndrome

Anti-synthetase syndrome is an autoimmune condition, characterized by antibodies directed against an aminoacycl transfer RNA synthetase along with clinical features that can include interstitial lung disease, myositis, Raynaud's phenomenon, and arthritis. There is a higher prevalence and increased severity of interstitial lung disease in patients with anti-synthetase syndrome, as compared to dermatomyositis and polymyositis, inflammatory myopathies with which it may overlap phenotypically. Diagnosis is made by a multidisciplinary approach, synthesizing rheumatology and pulmonary evaluations, along with serologic, radiographic, and occasionally muscle and/or lung biopsy results. Patients with anti-synthetase syndrome often require multi-modality immunosuppressive therapy in order to control the muscle and/or pulmonary manifestations of their disease. The long-term care of these patients mandates careful attention to the adverse effects and complications of chronic immunosuppressive therapy, as well as disease-related sequelae that can include progressive interstitial lung disease necessitating lung transplantation, pulmonary hypertension, malignancy and decreased survival. It is hoped that greater awareness of the clinical features of this syndrome will allow for earlier diagnosis and appropriate treatment to improve outcomes in patients with anti-synthetase syndrome.

Myositis-specific autoantibodies: an important tool to support diagnosis of myositis

The idiopathic inflammatory myopathies are characterized by muscle weakness, skin disease and internal organ involvement. Autoimmunity is known to have a role in myositis pathogenesis, and myositis-specific autoantibodies, targeting important intracellular proteins, are regarded as key biomarkers aiding in the diagnosis of patients. In recent years, a number of novel myositis autoantibodies including anti-TIF1, anti-NXP2, anti-MDA5, anti-SAE, anti-HMGCR and anti-cN1A have been identified in both adult and juvenile patients. These autoantibodies correlate with distinct clinical manifestations and importantly are found in inclusion body, statin-induced, clinically amyopathic and juvenile groups of myositis patients, previously believed to be mainly autoantibody negative. In this review, we will describe the main myositis-specific and myositis-associated autoantibodies and their frequencies and clinical associations across different ages and ethnic groups. We will also discuss preliminary studies investigating correlations between specific myositis autoantibody titres and clinical markers of disease course, collectively demonstrating the utility of myositis autoantibodies as both diagnostic and prognostic markers of disease.

Gottron Papules and Gottron Sign with Ulceration: A Distinctive Cutaneous Feature in a Subset of Patients with Classic Dermatomyositis and Clinically Amyopathic Dermatomyositis

OBJECTIVE

Gottron papules and Gottron sign are characteristic and possibly pathognomonic cutaneous features of classic dermatomyositis and clinically amyopathic dermatomyositis (DM/CADM). However, the Gottron papules/Gottron sign with cutaneous ulceration (ulcerative Gottron papules/Gottron sign) are less common. We aimed to clarify the clinical characteristics of patients with DM/CADM who have ulcerative Gottron papules/Gottron sign.

METHODS

Clinical features, laboratory findings, and prognosis of patients with DM/CADM who had Gottron papules/Gottron sign with or without ulceration were analyzed and compared.

RESULTS

Occurrences of acute interstitial pneumonia/subacute interstitial pneumonia (AIP/SIP) were significantly higher in patients with ulcerative Gottron papules/Gottron sign (19/26) versus patients with Gottron papules/Gottron sign without ulceration (2/66, p < 0.001). We also observed that the white blood cell counts (mean ± SD 4.2 ± 1.6 vs 6.9 ± 2.9; p < 0.001) and creatine kinase (CK) levels (198.0 ± 377.7 vs 1364.0 ± 2477.0; p = 0.019) were significantly lower, whereas the positive rate of antimelanoma differentiation-associated gene 5 antibody (anti-MDA5; 88.5% vs 6.1%, p < 0.001) and serum ferritin levels (665.2 ± 433.5 vs 256.2 ± 279.0, p < 0.001) were significantly higher in the patients with ulcerative Gottron papules/Gottron sign. Moreover, the cumulative survival rate of the group with ulcerative Gottron papules/Gottron sign was significantly lower (p < 0.001).

CONCLUSION

Patients with DM/CADM who have ulcerative Gottron papules/Gottron sign, positive anti-MDA5 antibody, and significantly lower baseline CK level are at increased risk of interstitial lung disease, especially AIP/SIP. A new designation for this subgroup of patients should be established to draw more attention to this clinical entity.

Factors Associated with Interstitial Lung Disease in Patients with Polymyositis and Dermatomyositis: A Systematic Review and Meta-Analysis

OBJECTIVES

Interstitial lung disease (ILD) is an extramuscular manifestation that results in increased morbidity and mortality from polymyositis (PM) and dermatomyositis (DM). The aim of this study was to systematically evaluate risk factors associated with the development of ILD in PM/DM.

METHODS

Observational studies were identified from searching PubMed, Medline, Embase, and the Cochrane Library. Pooled odds ratios (ORs) or standardized mean differences (SMDs) and corresponding 95% confidence intervals (CIs) were obtained for the relationships between risk factors and ILD in PM/DM using either fixed- or random-effects models, whichever were appropriate. Heterogeneity tests, sensitivity analyses, and publication bias assessments were also performed.

RESULTS

Twenty-three studies were selected for a meta-analysis that included 834 patients and 1245 control subjects. Risk factors that may have increased the risk of developing ILD in PM/DM patients included older age at diagnosis (SMD, 0.35; 95% CI, 0.18-0.52; P < 0.0001), arthritis/arthralgia (OR, 3.17; 95% CI, 1.99-5.04; P < 0.00001), fever (OR, 2.31; 95% CI, 1.42-3.76; P = 0.0007), presence of anti-Jo-1 antibodies (OR, 3.34; 95% CI, 2.16-5.16; P < 0.00001), elevated erythrocyte sedimentation rate (ESR; SMD, 0.48; 95% CI, 0.32-0.64; P < 0.00001), presence of anti-MDA5 antibodies (OR, 18.26; 95% CI, 9.66-34.51; P < 0.00001), and elevated C-reactive protein level (CRP; OR, 3.50; 95% CI, 1.48-8.28; P = 0.004). Meanwhile, malignancy (OR, 0.36; 95% CI, 0.18-0.72; P = 0.004) reduced the risk of developing ILD in PM/DM patients.

CONCLUSION

Our meta-analysis results suggest that the association between PM/DM and ILD may be due to such risk factors as older age at diagnosis, arthritis/arthralgia, fever, presence of anti-Jo-1 antibodies, elevated ESR, presence of anti-MDA5 antibodies, and elevated CRP level, while malignancy was associated with a reduced risk of developing ILD. Thus, these variables may be used to guide screening processes for ILD in patients with PM/DM.

Clinical Utility of an Enzyme-Linked Immunosorbent Assay for Detecting Anti-Melanoma Differentiation-Associated Gene 5 Autoantibodies

Objective

Autoantibodies to melanoma differentiation-associated gene 5 (MDA5) are specifically expressed in patients with dermatomyositis (DM) and are associated with a subset of DM patients with rapidly progressive interstitial lung disease (RP-ILD). Here, we examined the clinical utility of a newly developed enzyme-linked immunosorbent assay (ELISA) system for detecting these antibodies.

Methods

Here we developed an improved ELISA for detecting anti-MDA5 antibodies. We then performed a multicenter clinical study involving 8 medical centers and enrolled 242 adult patients with polymyositis (PM)/DM, 190 with non-PM/DM connective tissue disease (CTD), 154 with idiopathic interstitial pneumonia (IIP), and 123 healthy controls. Anti-MDA5 antibodies in the patients’ serum samples were quantified using our newly developed ELISA, and the results were compared to those obtained using the gold-standard immunoprecipitation (IP) assay. In addition, correlations between the ELISA-quantified anti-MDA5 antibodies and clinical characteristics were evaluated.

Results

In patients with PM/DM, the anti-MDA5 antibody measurements obtained from the ELISA and IP assay were highly concordant; the ELISA exhibited an analytical sensitivity of 98.2%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 99.5% (compared to the IP assay). Anti-MDA5 antibodies were detected in 22.7% of the DM patients, but not in any of the patients with PM, non-PM/DM CTD, or IIP. Clinically amyopathic DM, RP-ILD, arthritis, and fever were more prevalent in DM patients who were anti-MDA5 antibody-positive than in those who were antibody-negative (P ≤ 0.0002 for all comparisons). In addition, anti-MDA5 antibody-positive patients with RP-ILD exhibited higher antibody levels than those without RP-ILD (P = 0.006).

Conclusion

Our newly developed ELISA can detect anti-MDA5 antibodies as efficiently as the gold standard IP assay and has the potential to facilitate the routine clinical measurement of anti-MDA5 antibodies in patients who suspected to have DM.

Idiopathic inflammatory myopathies and the lung

Idiopathic inflammatory myositis (IIM) is a group of rare connective tissue diseases (CTDs) characterised by muscular and extramuscular signs, in which lung involvement is a challenging issue. Interstitial lung disease (ILD) is the hallmark of pulmonary involvement in IIM, and causes morbidity and mortality, resulting in an estimated excess mortality of 50% in some series. Except for inclusion body myositis, these extrapulmonary disorders are associated with the general and visceral involvement frequently found in other CTDs including fever, Raynaud's phenomenon, arthralgia, nonspecific cutaneous modifications and ILD, for which the prevalence is estimated to be up to 65%. Substantial heterogeneity exists within the spectrum of IIMs, and each condition is associated with various frequencies and subtypes of pulmonary involvement. This heterogeneity is partly related to the presence of various autoantibodies encompassing anti-synthetase, anti-MDA5 and anti-PM/Scl. ILD is present in all subsets of IIM including juvenile myositis, but is more frequent in dermatomyositis and overlap myositis. IIM can also be associated with other presentations of respiratory involvement, namely pulmonary arterial hypertension, pleural disease, infections, drug-induced toxicity, malignancy and respiratory muscle weakness. Here, we critically review the current knowledge about adult and juvenile myositis-associated lung disease with a detailed description of therapeutics for chronic and rapidly progressive ILD.

Severe respiratory failure as a presenting feature of an interstitial lung disease associated with anti-synthetase syndrome (ASS)

Anti-synthetase syndrome (ASS) is defined as a heterogeneous connective tissue disorder characterized by the association of an interstitial lung disease (ILD) with or without inflammatory myositis with the presence of anti-aminoacyl-tRNA-synthetase antibodies. ILD is one of the major extra-muscular manifestations of polymyositis and dermatomyositis. We report a case of a patient with dyspnea, cough, and intermittent fever as well as ILD associated ASS in the absence of muscular involvement. This patient was admitted to the emergency department with severe respiratory failure requiring non-invasive ventilation. Our patient's case demonstrates that the diagnosis of ASS may not be obvious. However, its diagnosis leads to appropriate and potentially life-saving treatment.

Interstitial lung disease in clinically amyopathic dermatomyositis with and without anti-MDA-5 antibody: to lump or split?

Background

Interstitial lung disease (ILD) associated with clinically amyopathic dermatomyositis (CADM-ILD) is often refractory and rapidly progressive. Although the anti-melanoma differentiation-associated gene 5 (anti-MDA-5) antibody is associated with rapidly progressive ILD (RP-ILD), differences in clinical features and prognosis of anti-MDA-5 antibody-positive and -negative CADM-ILD remain unclear.

Methods

To clarify the differences in the clinical features and prognosis between anti-MDA-5 antibody-positive and -negative cases, we retrospectively reviewed the medical records of patients diagnosed with CADM-ILD with and without anti-MDA-5 antibody at Kurashiki Central Hospital from January 2005 to September 2014.

Results

Anti-MDA-5 antibody was found in 10 of 16 patients (63 %). The levels of Krebs von den Lungen-6 (KL-6) and surfactant protein D (SP-D) at the first visit were significantly lower in positive patients than in negative patients, whereas the levels of aspartate aminotransferase (AST), γ-glutamyl transpeptidase (γ-GTP), and the CD4⁺/CD8⁺ ratio in the bronchoalveolar lavage (BAL) fluid were significantly higher in positive patients than negative patients. Subpleural ground-glass opacity (GGO) or irregular linear opacity was predominant in positive patients. Peribronchovascular consolidation was predominant in negative patients. Positive patients had significantly lower survival rates than negative patients, with all six fatal cases occurring in positive patients who died of refractory ILD within 92 days from the first visit despite intensive treatment.

Conclusions

There are clear differences in the clinical features and prognosis of anti-MDA-5 antibody-positive and -negative CADM-ILD. Low serum KL-6 and SP-D levels, high serum AST and γ-GTP levels, high CD4⁺/CD8⁺ ratio in BAL fluid, and predominance of subpleural GGO or irregular linear opacity in HRCT may help to discriminate anti-MDA-5 antibody-positive CADM-ILD with poor prognosis.

MDA5-positive dermatomyositis: an uncommon entity in Europe with variable clinical presentations

Clinically amyopathic dermatomyositis (CADM), described almost 50 years ago, is defined on the basis of still not validated criteria and characterized by skin findings almost without muscle weakness. Autoantibodies directed against the cytosolic pathogen sensor MDA5 (CADM 140) can mark this subtype of dermatomyositis which has been reported to associate, in particular ethnic groups, with severe progressive interstitial lung disease, poor prognosis and an hyperferritinemic status resembling hemophagocytic-like syndromes. MDA5 may be relevant in that Interferon-signature claimed to characterize inflammatory myopathies and dermatomyosits itself, but its role is not clear. However, the titre of anti-MDA5 autoantibodies seems to correlate with the outcome. In Caucasian populations the association between anti-MDA5 positive CADM and rapidly progressive interstitial lung disease seems to be weaker, but the limited numbers of patients described so far could explain the lack of statistical significance. As a fact, European patients with circulating anti-MDA5 autoantibodies may be clinically inhomogeneous and exhibit different rates of severity. The two patients affected by anti-MDA5 positive dermatomyositis described hereafter provide a clear example of the extreme variability of the disease in terms of laboratory findings and clinical features.

Interstitial lung disease associated with the idiopathic inflammatory myopathies and the antisynthetase syndrome: recent advances

PURPOSE OF REVIEW

To highlight recent advances in understanding the clinical spectrum, pathogenesis, and treatment of interstitial lung disease associated with inflammatory myositis and the antisynthetase syndrome.

RECENT FINDINGS

In recent years, serologic tests to identify the less common antisynthetase antibodies and the anti-MDA-5 antibody have become commercially available. As a result, several large, retrospective analyses have illustrated both the pulmonary and non-pulmonary features associated with the antisynthetase syndrome and myositis-related interstitial lung disease. Notably, there is now a better appreciation for the heterogeneity of these syndromes and the prognostic value in accurately identifying the associated autoantibodies. Human cytokine profiling and murine models of muscle inflammation suggest that tRNA synthetases themselves may act to trigger an initial innate immune response, thus offering new insights into the pathophysiology of these diseases. Finally, although randomized clinical trials in patients with myositis-associated interstitial lung disease have not occurred, new observational studies suggest that cyclosporine, tacrolimus, and rituximab may be effective treatment options.

SUMMARY

Recent research has provided a better understanding of the phenotype and prognosis that define interstitial lung disease in the setting of myositis and the antisynthetase syndrome. Although several therapeutic agents demonstrate promise, randomized trials are needed in order to establish the best clinical approach in these patients. Furthermore, additional research into the pathophysiology of this disease will be necessary to develop newer, more targeted therapeutics.

Distinct profiles of myositis-specific autoantibodies in Chinese and Japanese patients with polymyositis/dermatomyositis

The study aims to comprehensively assess the profiles of myositis-specific autoantibodies (MSAs) in Chinese patients with polymyositis (PM)/dermatomyositis (DM) and compare them with a Japanese cohort. One hundred forty-five Chinese patients (68 classic DM, 25 clinically amyopathic DM [CADM], and 52 PM) and 165 Japanese patients (56 classic DM, 52 CADM, and 57 PM) were recruited. MSAs were measured with immunoprecipitation, enzyme-linked immunosorbent assay, or immunoprecipitation-immunoblotting. MSA frequencies were compared. The overall frequency of anti-melanoma differentiation-associated gene 5 (MDA5) antibodies was significantly higher in the Chinese patients than in the Japanese cohort (36.6 % [53/145] versus 15.8 % [26/165], respectively, P < 0.001), whereas the frequencies of anti-signal recognition particle (SRP) antibodies (1.4 % [2/145] versus 7.9 % [13/165], respectively, P = 0.008) and anti-aminoacyl-transfer RNA synthetase (anti-ARS) antibodies (27.6 % [40/145] versus 40 % [66/165], respectively, P = 0.02,) were significantly lower. The significantly lower frequency of anti-ARS antibodies and significantly higher frequency of anti-MDA5 antibodies in the Chinese patients were observed in the classic DM subset (14.7 % [10/68] versus 46.4 % [26/56], respectively, P < 0.001, and 45.6 % [31/68] versus 5.4 % [3/56], respectively, P < 0.001) and CADM subset (8.0 % [2/25] versus 28.8 % [15/52], respectively, P = 0.04, and 88.0 % [22/25] versus 44.2 % [23/52], respectively, P = 0.0002), but not in the PM subset. The first detailed profile of MSAs in Chinese patients with PM/DM was established. The differences in MSA frequencies in the Chinese cohort and Japanese cohort suggest underlying genetic and/or environmental differences between these two populations. Key Messages • A significantly higher frequency of anti-melanoma differentiation-associated gene 5 (MDA5) antibodies was observed in Chinese patients with polymyositis/dermatomyositis (PM/DM) than in Japanese patients. • Our findings suggest that distinct genetic and/or local environmental factors affect Chinese and Japanese patients with PM/DM, who have been considered a "homogeneous" population in previous studies.

Refractory Dermatomyositis Complicated with Myelodysplastic Syndrome

We herein describe a case of refractory dermatomyositis (DM) complicated with myelodysplastic syndrome (MDS). Despite intensive immunosuppressive therapies, the activity of myositis, skin ulcers, and interstitial pneumonia did not improve. The patient ultimately died following the progression of interstitial pneumonia. There are few reports of DM accompanying MDS to date, and any association in the pathogenesis between the two is still unclear. However, underlying MDS may have the potential to influence the therapeutic response of DM.

[What's new in internal medicine?]

This article focuses on current trends in various autoimmune diseases of interest for the dermatologist. In the antiphospholipid syndrome, many news: better characterization of the severe disease, involvement of the mTOR pathway in the vasculopathy-induced renal disease, and diversification of the therapeutic approaches: use of mTOR inhibitors and several biologics, new various antiplatelet and anticoagulants. In dermatomyositis, new autoantibodies are better characterized with a good correlation with clinical disease; the results of a large study on genetic predisposition to the disease are available. There are also some therapeutic innovations in systemic sclerosis: benefit of rituximab that seems well tolerated, the results of a large controlled European study about aggressive immunoablative chemotherapy followed by autologous stem cells have just been published, intralesional stem cells injections in the fingers of sclerodactylic patients. Finally, news in celiac disease that is constantly increasing and whose mild forms often have cutaneous manifestations, leading to diagnosis.

A case of sarcoidosis with interstitial lung disease mimicking clinically amyopathic dermatomyositis and rapidly progressive interstitial lung disease

Here, we report a patient with sarcoidosis who developed edematous erythema and interstitial lung disease. At the initial visit, clinically amyopathic dermatomyositis (CADM) with rapidly progressive interstitial lung disease (RP-ILD) was suspected because he had progressive dyspnea but no muscle weakness. The presence of anti-CADM-140/MDA5 autoantibodies was immediately assessed to facilitate a precise diagnosis, with negative results. Thereafter, skin and transbronchial lung biopsies revealed noncaseating granuloma with Langhans giant cells in both specimens, leading to a diagnosis of sarcoidosis. In this case, clinical features of skin and lung were unable to distinguish DM (including CADM) from sarcoidosis, but the lack of anti-CADM-140/MDA5 antibody was useful for differentiating CADM with RP-ILD mimicking sarcoidosis from bona fide sarcoidosis.

Redefining dermatomyositis: a description of new diagnostic criteria that differentiate pure dermatomyositis from overlap myositis with dermatomyositis features

Dermatomyositis (DM) is a major clinical subset of autoimmune myositis (AIM). The characteristic DM rash (Gottron papules, heliotrope rash) and perifascicular atrophy at skeletal muscle biopsy are regarded as specific features for this diagnosis. However, new concepts are challenging the current definition of DM. A modified Bohan and Peter classification of AIM was proposed in which the core concept was the inclusion of the diagnostic significance of overlap connective tissue disease features. In this clinical classification, a DM rash in association with myositis in the absence of overlap features indicates a diagnosis of pure DM. However, overlap features in association with myositis allow a diagnosis of overlap myositis (OM), irrespective of the presence or absence of the DM rash. Perifascicular atrophy may be present in both pure DM and OM. Recently, the presence of perifascicular atrophy in myositis without a DM rash was proposed as diagnostic of a novel entity, adermatopathic DM. We conducted the present study to evaluate these new concepts to further differentiate pure DM from OM.Using the modified Bohan and Peter classification, we performed a follow-up study of a longitudinal cohort of 100 consecutive adult French Canadian patients with AIM, including 44 patients with a DM phenotype, defined as a DM rash, and/or DM-type calcinosis, and/or the presence of perifascicular atrophy on muscle biopsy. A detailed evaluation was performed for overlap features, the extent and natural history of the DM rash, adermatopathic DM, DM-specific and overlap autoantibodies by protein A immunoprecipitation on coded serum samples, and associations with cancer and survival.Two distinct subsets were identified in patients with a DM phenotype: pure DM (n = 24) and OM with DM features, or OMDM (n = 20). In pure DM, the DM rash was a dominant finding. It was the first disease manifestation, was always present at the time of myositis diagnosis, and was associated with a high cutaneous score and chronicity. Concurrent heliotrope rash and Gottron papules (positive predictive value [PPV] 91%), as well as the V-sign and/or shawl sign (PPV 100%), were diagnostic of pure DM. Anti-Mi-2, anti-MJ, and anti-p155 autoantibodies were present in 50% of pure DM patients and were restricted to this subset (PPV 100%). Cancer was present in 21% of pure DM patients. The 15-year survival was excellent (92%).In contrast, in patients with OMDM, the first manifestation was proximal muscle weakness or other skeletal muscle-related complaints. The DM rash appeared at diagnosis or at follow-up, was associated with a low cutaneous extent score and was transient. Adermatopathic DM, which was absent in pure DM, was highly predictive (PPV 100%) of OMDM. Overlap autoantibodies (including anti-Jo-1, anti-PL-7, anti-PM-Scl, anti-U1RNP, and/or anti-U5-RNP) were found in 70% of OMDM patients. OMDM was not associated with cancer, but the 15-year survival was significantly decreased (65%).Perifascicular atrophy occurred as commonly in OMDM (n = 6/20, 30%) as in pure DM (n = 4/24, 17%) patients. These 6 OMDM patients had adermatopathic DM at myositis diagnosis, and only 1 of them developed a DM rash at follow-up, emphasizing the lack of specificity of perifascicular atrophy for pure DM.In conclusion, using the modified Bohan and Peter classification of AIM allowed identification of OMDM, a new clinical subset of OM. Furthermore, identification of OMDM allowed recognition of pure DM as a new entity that was distinct from OMDM or from OM without DM features. However, the absolute specificity of a DM rash and perifascicular muscle atrophy for the diagnosis of pure DM was lost. The distinctive clinical manifestations and autoantibody profiles presented are proposed as diagnostic criteria to differentiate pure DM from OMDM.