Abstract: Abstract: Objective To summarize the experience of diagnosis and treatment of clinical data of 2 dead cases with clinically amyopathic dermatomyositis (CADM) and rapidly-progressive interstitial lung disease (RP-ILD). Methods The clinical manifestations, laboratory and imaging examination results, diagnosis and treatment of 2 dead cases with CADM of RP-ILD treated in our hospital from February, 2015 to January, 2018 were analyzed retrospectively. The clinical characteristics, treatment plan and cause of death were summarized. Results The 2 dead cases with CADM of RP-ILD were tested positive for the anti-melanoma differentiation-associated gene 5 (MDA5) antibody. The SF level was significantly increased in the 2 patients at admission, but the CT scan-chest only indicated the mild inflammation. With the progressively exacerbation of the patient respiration, the SF level was increased progressively, and the chest imaging progressed. The combination of hormone, tacrolimus and cyclophosphamide were given for treatment in the two patients. The 2 patients died of respiratory failure at 66 days and 61 days respectively. Conclusion The high SF level reflects the deterioration in patients with DM of ILD associated with anti-MDA5 antibody. In determining the progression of the disease, the SF level has earlier diagnostic value than chest CT scan.

Key words: dermatomyositis, lung diseases, interstitial, clinically amyopathic, melanoma diferentiation-associated gene 5, serum ferritin