Describing and expanding the clinical phenotype of anti-MDA5-associated rapidly progressive interstitial lung disease: case series of nine Canadian patients and literature review

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) positive dermatomyositis: early detection is crucial

Anti-melanoma differentiation-associated gene 5-positive (Anti-MDA5) dermatomyositis (DM) is an aggressive phenotype of DM associated with rapidly progressive interstitial lung disease (RP-ILD). It is a rare condition that carries high mortality. Diagnosis and management of patients with anti-MDA5 DM RP-ILD presents several challenges, including uncertainty around treatment algorithms and a lack of evidence to inform practice. This case report of a patient with anti-MDA5 DM RP-ILD highlights these challenges, emphasising the fulminant course of this disease despite aggressive immunosuppression. Further research is required to guide management and to minimise morbidity and mortality, and greater awareness of the condition is required to minimise delays in diagnosis.

An Adolescent Case of Anti-MDA5 Antibody-Positive Juvenile Dermatomyositis With Interstitial Lung Disease Successfully Treated by Multitarget Therapy Avoiding Cyclophosphamide: A Case Report and Literature Review

Juvenile dermatomyositis (JDM) patients who test positive for the antimelanoma differentiation-associated gene 5 (MDA5) antibody have a poor prognosis because of rapidly progressing interstitial lung disease (ILD). However, agreement on the best treatment for this condition remains elusive. We encountered a 13-year-old girl with anti-MDA5 antibody-positive JDM who presented with arthritis and was already showing signs of ILD when she was admitted to the hospital. While cyclophosphamide (CY) is commonly used, it can cause gonadal disorders and other complications when administered to adolescent females. Consequently, we chose multitarget therapy, which includes tacrolimus and mycophenolate mofetil. Her ILD and skin symptoms gradually improved, and she was able to maintain remission and avoid CY administration for three years. We conducted a thorough literature review to determine the efficacy and safety of multitarget therapy for anti-MDA5 antibody-positive DM and JDM. Multitarget therapy shows promise as a potentially effective and relatively safe treatment. The ability to avoid CY, which is especially important for adolescent patients concerned about fertility preservation, highlights a significant benefit of this multitarget therapy for anti-MDA5 antibody-positive DM and JDM patients.

Differences in sex- and age-associated mortality in patients with anti-MDA5-positive dermatomyositis

OBJECTIVES

The effect of sex and age on the outcomes of patients with anti-melanoma differentiation-associated gene 5 (MDA5)-positive dermatomyositis (MDA5+ DM) remains unclear. This study aimed to investigate the impact of sex and age on the prognosis of patients with MDA5+ DM.

METHODS

We included 251 patients (women, 156; men, 95), who were newly diagnosed with MDA5+ DM between 2014 and 2021. The outcome was 6-month all-cause mortality after the diagnosis of interstitial lung disease. Cox regression analysis was used to assess the mortality. Adjusted restricted cubic spline analysis was performed to explore the non-linear relationship between age and outcomes.

RESULTS

The 6-month mortality rates of women and men were 36.5% and 46.3%, respectively. Multivariate Cox regression revealed that ≥60 years of age was significantly associated with the risk of death (hazard ratio, 2.43; 95% confidence interval, 1.02-5.78). The trend of the risk of 6-month mortality in men was relatively flat until 54 years and increased rapidly afterwards (hazard ratio, 1.14; 95% confidence interval, 1.01-1.29). In contrast, the 6-month mortality rate showed a low linear increasing trend with age among females.

CONCLUSIONS

Patients with MDA5+ DM, who received contemporary treatment, had unfavourable outcomes. The 6-month mortality risk increased with age, particularly in male patients aged >54 years.

Different Multivariable Risk Factors for Rapid Progressive Interstitial Lung Disease in Anti-MDA5 Positive Dermatomyositis and Anti-Synthetase Syndrome

Background

Interstitial lung disease (ILD) is frequently observed in anti-melanoma differentiation-associated protein 5 (MDA5) antibody positive dermatomyositis (DM) and anti-synthetase syndrome (ASS), where they often develop a rapidly progressive ILD (RP-ILD) leading to poor prognosis.

Objective

The aim of this study was to construct multivariable prediction risk factors for rapid progressive ILD (RP-ILD) in anti-MDA5 positive DM (MDA5+DM) and ASS.

Methods

333 idiopathic inflammatory myopathy (IIM) associated ILD patients were studied retrospectively. Risk factors for RP-ILD in MDA5+DM and ASS patients were identified by univariate and multivariable logistic regression analysis. The mortality was assessed using Kaplan-Meier analysis.

Results

RP-ILD was more prevalent in MDA5+DM patients than ASS patients. MDA5+DM patients with RP-ILD had significantly lower survival rates than those in ASS patients. The independent risk factors for RP-ILD in MDA5+DM patients were fever (OR 3.67, 95% CI:1.79-7.52), lymphopenia (OR 2.14, 95% CI:1.01-4.53), especially decreased levels of CD3+T cells (OR 2.56, 95% CI:1.17-5.61), decreased levels of CD3+CD4+ T cells (OR 2.80, 95% CI:1.37-5.73), CD3+CD8+T cells (OR 2.18, 95% CI:1.05-4.50), elevated CD5-CD19+ B cells (OR 3.17, 95% CI:1.41-7.13), elevated ALT (OR 2.36, 95% CI:1.15-4.81), high lactate dehydrogenase (LDH) (OR 3.08, 95% CI:1.52-6.27), hyper-ferritin (OR 4.97, 95% CI:1.97-12.50), elevated CEA (OR 2.28, 95% CI:1.13-4.59), and elevated CA153 (OR 3.31, 95% CI:1.50-7.27). While the independent risk factors for RP-ILD in ASS patients were elevated CEA (OR 5.25, 95% CI: 1.73-15.93), CA125 (OR 2.79, 95% CI: 1.10-7.11) and NSE (OR 4.86, 95% CI: 1.44-16.37). Importantly, serum ferritin>2200ng/ml predicted patient’s death within half a year in MDA5+DM patients with RP-ILD, but not in ASS patients.

Conclusions

There were significant different mortality and multivariable risk factors for RP-ILD in MDA5+DM patients and ASS patients. Potential clinical benefits of using these different risk factors deserve assessment of severity and prognosis in IIM patients.

Predictors of rapidly progressive- interstitial lung disease and mortality in patients with autoantibodies against melanoma differentiation-associated protein 5 dermatomyositis

Objective

Anti-melanoma differentiation-associated protein 5 (MDA5) positive dermatomyositis (DM) is associated with rapidly progressive interstitial lung disease (RP-ILD) and high mortality. This multicentre retrospective study aimed to identify predictors for mortality and RP-ILD.

Methods

Anti-MDA5 positive DM patients were identified from the Hong Kong Myositis Registry and the Clinical Data Analysis and Reporting System. Clinical characteristics were reviewed. Risk factors for mortality and RP-ILD were identified.

Results

Among the 116 recruited patients, 100 (86.2%) had ILD, 47 (40.5%) had RP-ILD and 44 (37.9%) patients died. Cox regression analysis revealed that RP-ILD (HR 9.735, 95%CI 3.905–24.272), age >52 (HR 4.750, 95%CI 1.692–13.333), ferritin level >2800pmol/l (HR 3.042, 95%CI 1.323–6.997) and lactate dehydrogenase (LDH) >400 IU/l (HR 2.290, 95% CI 1.009–5.198) were independent predictors of mortality. With regard to RP-ILD, analyses showed that potential predictors at baseline included age >50 years old (HR 2.640, 95%CI 1.277–5.455), LDH >300IU/l (HR3.189, 95%CI 1.469–6.918), fever (HR 1.903, 95% CI: 0.956–3.790) and neutrophil to lymphocyte ratio (NLR) >7.0 (HR 1.967, 95%CI 0.942–4.107). We proposed a prediction model, based on Fever, LDH, Age and White cell count (“FLAW”), to stratify risk of development of RP-ILD. The probability of RP-ILD in a patient with a score of 4 was 100%. A small internal validation cohort showed the odds of RP-ILD with FLAW scores of 0, 1, 2 and 3 were 0%, 0%, 42.9% and 75% respectively.

Conclusions

Anti-MDA5-associated RP-ILD is significantly associated with poor survival rates. The “FLAW” model maybe useful to predict the development of RP-ILD.

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

Objective

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

Methods

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

Results

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

Conclusion

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

Systematic Review Registration

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

Role of antifibrotics in the management of idiopathic inflammatory myopathy associated interstitial lung disease

The antifibrotic therapies nintedanib and pirfenidone were first approved by the United States for the treatment of idiopathic pulmonary fibrosis in 2014. In 2020, nintedanib received U.S. Food and Drug Administration (FDA) approval for the treatment of all progressive fibrosing interstitial lung disease (ILD). Given that a major cause of mortality and morbidity in the idiopathic inflammatory myopathies (IIM) is progressive interstitial lung disease and respiratory failure, antifibrotic therapies may be useful as adjuvant to traditional immunosuppression. However, randomized controlled trials of antifibrotic therapies in IIM are lacking. The purpose of this review is to (1) summarize the mechanism of action of nintedanib and pirfenidone in ILD with possible role in IIM-ILD, (2) review the clinical data supporting their use in interstitial lung disease in general, and more specifically in connective tissue disease associated ILD, and (3) discuss the evidence and remaining challenges for using antifibrotic therapies in IIM-ILD.

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

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

Role of autoantibodies in the diagnosis and prognosis of interstitial lung disease in autoimmune rheumatic disorders

Interstitial lung disease (ILD) has been recognized as a frequent manifestation associated with a substantial morbidity and mortality burden in patients with autoimmune rheumatic disorders. Serum autoantibodies are considered good biomarkers for identifying several subsets or specific phenotypes of ILD involvement in these patients. This review features the role of several autoantibodies as a diagnostic and prognostic biomarker linked to the presence ILD and specific ILD phenotypes in autoimmune rheumatic disorders. The case of the diverse antisynthetase antibodies in the antisynthease syndrome or the anti-melanoma differentiation-associated 5 protein (MDA5) antibodies as a marker of a severe condition such as rapidly progressive ILD in patients with clinically amyopathic dermatomyositis are some of the associations herein reported in the group of myositis spectrum disorders. Specific autoantibodies such as the well-known anti-topoisomerase I (anti-Scl70) or the anti-Th/To, anti-U11/U12 ribonucleoprotein, and anti-eukaryotic initiation factor 2B (eIF2B) antibodies seems to be specifically linked to ILD in patients with systemic sclerosis. Overlap syndromes between systemic sclerosis and myositis, also have good ILD biomarkers, which are the anti-PM/Scl and anti-Ku autoantibodies. Lastly, other not so often reported disorders as being associated with ILD but recently most recognized as is the case of rheumatoid arthritis associated ILD or entities herein included in the miscellaneous disorders section, which include anti-neutrophil cytoplasmic antibody-associated interstitial lung disease, Sjögren's syndrome or the mixed connective tissue disease, are also discussed.

Anti-MDA5 autoantibodies associated with juvenile dermatomyositis constitute a distinct phenotype in North America

OBJECTIVE

Myositis-specific autoantibodies have defined distinct phenotypes of patients with juvenile myositis (JIIM). We assessed the frequency and clinical significance of anti-melanoma differentiation-associated gene 5 (MDA5) autoantibody-associated JIIM in a North American registry.

METHODS

Retrospective examination of the characteristics of 35 JIIM patients with anti-MDA5 autoantibodies was performed, and differences from other myositis-specific autoantibody groups were evaluated.

RESULTS

Anti-MDA5 autoantibodies were present in 35/453 (7.7%) of JIIM patients and associated with older age at diagnosis, and lower serum creatine kinase and aldolase levels. Patients with anti-MDA5 autoantibodies had more frequent weight loss, adenopathy, arthritis, interstitial lung disease (ILD), and less frequent falling compared with anti-transcriptional intermediary factor 1 (TIF1), anti-nuclear matrix protein 2 (NXP2) and myositis-specific autoantibody/myositis-associated autoantibody-negative patients. They had a different season of diagnosis and less frequent mechanic's hands and ILD compared with those with anti-synthetase autoantibodies. Anti-MDA5 patients received fewer medications compared with anti-TIF1, and corticosteroid treatment was shorter compared with anti-TIF1 and anti-nuclear matrix protein 2 autoantibody groups. The frequency of remission was higher in anti-MDA5 than anti-synthetase autoantibody-positive JIIM. In multivariable analyses, weight loss, arthritis and arthralgia were most strongly associated with anti-MDA5 autoantibody-positive JIIM.

CONCLUSION

Anti-MDA5 JIIM is a distinct subset, with frequent arthritis, weight loss, adenopathy and less severe myositis, and is also associated with ILD. Anti-MDA5 is distinguished from anti-synthetase autoantibody-positive JIIM by less frequent ILD, lower creatine kinase levels and differing seasons of diagnosis. Anti-MDA5 has comparable outcomes, but with the ability to discontinue steroids more rapidly and less frequent flares compared with anti-TIF1 autoantibodies, and more frequent remission compared with anti-synthetase JIIM patients.

Disease characteristics and clinical outcomes of adults and children with anti-MDA-5 antibody-associated myositis: a prospective observational bicentric study

To study the demographic, clinical and serologic characteristics of anti-MDA5-positive DM from two geographically and ethnically disparate inception cohorts in India. To identify the clinical and serological parameters at inception that could predict mortality among these individuals. Individuals with anti-MDA5 antibody-positive DM diagnosed between 2017 and 2020 from two centres in India were prospectively followed up. The clinical and serological characteristics at baseline and the treatment outcome at follow-up were assessed for this study. Anti-MDA5 antibody was positive in 25 (7.5%) out of the 330 individuals with myositis. These 25 (21 adults, 4 juvenile) patients were followed up for a median duration of 14 months. Among adults, a majority had cutaneous manifestations 21 (84%) followed by, arthritis 17 (80%), and interstitial lung disease 12 (ILD, 57.1%). Four (19%) had rapidly progressive ILD (RP-ILD). Eight (38%) presented as clinically amyopathic DM. Among cutaneous manifestations, majority (62%) had classic features (gottron's papules/sign, heliotrope rash) while 8 (38%) had cutaneous ulceration and 2 each had periorbital edema and tendon rupture. Eight (38%) were positive for anti-Ro-52 antibody. Out of 21 adults, 8 (38%) succumbed to the diseases. RP-ILD (n = 4; 19%), ulcerative gottron's (n = 5) and anti-Ro-52 (n = 8) were significantly associated with mortality (p < 0.05). Upon binary logistic regression, positive anti-Ro-52 antibody predicted mortality [HR 17.3 (95%CI 1.4-210, p = 0.025)]. All juvenile anti-MDA5-positive DMs had classic cutaneous features with 2 of them having ulcerative gottron's. None of the juvenile patients had ILD and everyone survived till the last follow-up. Indian adults with anti-MDA5 DM have high mortality. Rarer atypical features like tendon rupture or periorbital edema could assist in diagnosis. Ulcerative gottron's, positive anti-Ro 52 antibodies, and RP-ILD are valuable clinical-serological markers that portend poor prognosis.

Case Report: Rapidly Progressive Interstitial Lung Disease in A Pregnant Patient With Anti-Melanoma Differentiation-Associated Gene 5 Antibody-Positive Dermatomyositis

Dermatomyositis occurs extremely rarely during pregnancy. A number of studies in the published literature have documented how the outcome of pregnancy is poor for both mother and fetus. The present case study reports on a patient who was diagnosed with clinically amyopathic dermatomyositis complicated by interstitial lung disease during pregnancy, and was successfully treated with a combined immunosuppressant regimen. To the best of the authors' knowledge, this is the first case study detailing how a pregnant woman with clinically amyopathic dermatomyositis with positive anti-melanoma differentiation-associated gene 5 antibody achieved complete remission after early intervention of combined immunosuppressive therapy without residual pulmonary interstitial changes.

A case of anti-MDA5 antibody-positive dermatomyositis developing reversible cerebral vasospasm syndrome successfully treated by multi-immunosuppressant combination including mycophenolate mofetil

A 39-year-old woman admitted with multiple joint pain, hand rashes, and shortness of breath was diagnosed with anti-melanoma differentiation-associated gene 5 (MDA5) antibody-positive dermatomyositis (DM) with interstitial pneumonia (IP). Because of progressive dyspnoea and hypoxaemia, her IP was considered rapidly progressive interstitial lung disease. Initially, prednisolone 60 mg/day, cyclosporine A (CyA), and intravenous cyclophosphamide (IVCY) were initiated. A few days following the initiation of treatment, she experienced massive thunderclap headache, which was diagnosed as reversible cerebral vasospasm syndrome based on the findings of contraction in cerebral arteries with brain magnetic resonance imaging. Treatment with CyA and IVCY was discontinued, and diltiazem and mycophenolate mofetil (MMF) were initiated as an alternative immunosuppressant. Considering IVCY as the cause of Reversible cerebral vasospasm syndrome based on her clinical course, tacrolimus was commenced, which improved both DM and IP. DM patients who are anti-MDA5 antibody-positive are considered to have poor prognosis and require aggressive immunosuppressive treatments. In patients experiencing adverse events with standard IVCY, MMF with high-dose steroids and alternative calcineurin inhibitor should be considered.

Coronavirus disease 2019-associated rapidly progressive organizing pneumonia with fibrotic feature: Two case reports

INTRODUCTION

Pneumonia is one of the most important characteristics of coronavirus disease 2019 (COVID-19) and imaging findings of COVID-19 pneumonia are diverse and change over disease course. However, the detailed clinical course of organizing pneumonia (OP) caused by COVID-19 has not been clarified.

PATIENT CONCERNS

A 60-year-old man and a 61-year-old woman diagnosed with mild COVID-19 were admitted to our hospital. Their respiratory symptoms were deteriorating even after initiating treatment with antiviral drugs.

DIAGNOSIS

Chest X-rays and computed tomography scan showed a rapid progression of linear consolidation with reversed halo sign, distributed in subpleural and peri-bronchial regions. They also presented with pulmonary fibrosis findings, including traction bronchiectasis and marked lung volume reduction. They were diagnosed with rapidly progressing OP.

INTERVENTIONS

They were treated with systemic corticosteroids.

OUTCOMES

The patients' imaging findings and respiratory conditions improved rapidly without any adverse effects.

CONCLUSION

Physicians should carefully monitor patients with COVID-19, as they can develop rapidly progressive and fibrotic OP, which respond to corticosteroids.

Interstitial Lung Disease-Complicated Anti-MDA5 Antibody in Clinically Amyopathic Dermatomyositis Patients: Report of Two Cases With Distinct Clinical Features

Two patients presented simultaneously to our hospital with distinct clinical features associated with the presence of anti-MDA5 antibodies: the first one was admitted for a skin rash resembling to a toxic epidermal necrosis (Lyell syndrome) and the second one presented with pulmonary manifestations attributed to a diffuse fibrosing interstitial pneumonitis on chest CT-scan. In addition to the skin lesions involving 40% of the body surface area, the first patient developed a rapid diffuse interstitial pneumonitis with respiratory distress justifying the initiation of a systemic immunosuppressive treatment. However, she died 3 weeks after her admission from mesenteric thrombosis associated with septic shock. The second patient respiratory condition worsened despite an intensive immunosuppressive treatment with high doses of intravenous methylprednisolone and cyclophosphamide and plasmapheresis, and required lung transplantation. Anti-MDA5 antibody titer declined and disappeared on anti-rejection treatment. These two cases underline the diagnostic conundrum and the therapeutic difficulties in patients with anti-MDA5 antibodies and clinically amyopathic dermatomyositis (CADM) or interstitial lung disease (ILD), who may undergo rapidly-progressive and fatal outcome. Presence of anti-MDA5 antibodies should always be suspected when confronted to CADM patients with cutaneous ulcerations or ILD to allow a rapid and adapted treatment initiation.

Rheumatoid Arthritis Complicated with Anti-melanoma Differentiation-associated Gene 5 Antibody-positive Interstitial Pneumonia

Anti-melanoma differentiation-associated gene 5 (MDA5) antibodies are frequently detected in amyopathic dermatomyositis with rapidly progressive interstitial lung disease (RP-ILD). However, the presence of anti-MDA5 antibodies in other connective tissue diseases is not well known. We herein report a case of rheumatoid arthritis complicated with refractory anti-MDA5 antibody-positive ILD. A 75-year-old Japanese woman was referred to our hospital for refractory ILD. Serological testing was positive for anti-MDA5 antibody without any muscle or skin lesions. Immunosuppressive therapy (prednisolone and tacrolimus) ameliorated her symptoms as well as ILD. Anti-MDA5 antibody-positive ILD, as well as dermatomyositis with RP-ILD, can occur in patients with rheumatoid arthritis.

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.