Case report: Successful treatment of anti‐MDA5‐positive to negative dermatomyositis‐associated interstitial lung disease with the JAK inhibitor tofacitinib

OBJECTIVE: Anti‐MDA5 antibody‐positive dermatomyositis (DM) is a rare clinical autoimmune disease, and anti‐MDA5‐positive DM with interstitial lung disease (ILD) is the most important cause of death in DM patients. We reported the efficacy of the JAK1/3 inhibitor tofacitinib as an anti‐MDA5‐negative treatment option for patients with anti‐MDA5‐positive DM‐ILD. METHOD AND PROCESS: Here we report a 51‐year‐old female patient with cough, sputum, shortness of breath for 5 months, rash for 3 months, and muscle pain in the extremities for 1 month. After conventional immunosuppressive therapy plus hormone therapy, the remission was slow. Methylprednisolone was successfully reduced after we administered tofacitinib and tacrolimus. After 132 weeks of follow‐up, anti‐MDA5 antibody turned negative, clinical symptoms were relieved, and lung Imaging tests were successfully reversed. RESULTS AND CONCLUSION: There is currently no report of tofacitinib supplement therapy for anti‐MDA5 positive to negative DM. With this case report, tofacitinib is an option for the treatment of anti‐MDA5‐positive DM‐ILD, which deserves attention.