Clinical characteristics of anti‐MDA5 antibody‐positive interstitial lung disease

Clinically amyopathic dermatomyositis (CADM) with anti‐melanoma differentiation‐associated gene 5 antibody is associated with rapidly progressive interstitial lung disease (RP‐ILD) which results in up to 50% mortality, especially within six months of diagnosis. However, limited data are available on this disease. This is the first case series of six patients in Thailand diagnosed with CADM with ILD. All patients presented with respiratory symptoms, such as progressive dyspnoea, dyspnoea on exertion, or cough. High‐resolution computed tomography of the chest showed predominantly subpleural and peripheral consolidation in both lower lungs. Four patients had RP‐ILD and three of the RP‐ILD patients died within seven weeks of diagnosis. These cases illustrate the clinical characteristics, chest imaging, treatments, and clinical outcomes of the patients diagnosed with CADM and ILD.