However, in the present study, we encountered a case of rapidly progressive interstitial lung disease (RP-ILD) complicated by anti-MDA5 antibody-positive dermatomyositis, which developed into respiratory failure due to the re-aggravation of diffuse ground-glass opacity (GGO) during treatment, leading to the diagnosis of APAP. The gene discussed is IFIH1; the disease is interstitial lung disease.