Tofacitinib for recurrence of antimelanoma differentiation-associated gene 5 antibody-positive clinically amyopathic dermatomyositis after remission: A case report.

RATIONALE: Antimelanoma differentiation-associated gene 5 antibody (anti-MDA5 Ab)-positive clinically amyopathic dermatomyositis (cADM) is frequently complicated with interstitial lung disease (ILD) and has a poor prognosis. Although the short-term prognosis of anti-MDA5 Ab-positive cADM is poor, it has been suggested that the recurrence rate is not higher than that of anti-MDA5 Ab-negative dermatomyositis. Combination therapy with corticosteroids, calcineurin inhibitors, and cyclophosphamide is the gold standard for the remission induction therapy at the onset. Recently, it has been reported that tofacitinib (TOF) could be effective for refractory anti-MDA5 Ab-positive cADM with ILD. Although initial remission induction therapy has been established, therapeutic strategies for relapse cases have not yet been established. PATIENT CONCERNS: A 57-year-old woman who was diagnosed with anti-MDA5 Ab-positive cADM complicated with ILD. In October 2016, she was treated with prednisolone (PSL), tacrolimus (TAC), and cyclophosphamide (CY). These treatments were successful, and PSL could be tapered. However, she developed strong nausea and general fatigue as adverse events of CY. In April 2018, PSL was discontinued, and maintenance therapy was given with TAC. In July 2018, Gottron's sign and ILD recurred. Skin lesions on the finger were partially ulcerated and ILD was also worsening. We proposed a remission reinduction therapy including CY. However, she was rejected CY from experience with past adverse event of CY. DIAGNOSIS: Based on skin lesions and chest computed tomography (CT) findings, the diagnosis was a recurrence of anti-MDA5 Ab-positive cADM with ILD. INTERVENTIONS: Treatment by TOF 10 mg and PSL 22.5 mg (0.5 mg/kg equivalent) was introduced in November 2018. OUTCOMES: After introducing TOF and PSL, her skin lesions and chest CT findings of ILD gradually improved. Six months after the induction of TOF, the skin ulcer was epithelialized. One year after the introduction of TOF, PSL was decreased to 9 mg, and the disease activity did not re-exacerbate. LESSONS: This case report is the first report suggesting the effectiveness of TOF for recurrent case of anti-MDA5 Ab-positive cADM with ILD. TOF might be an effective therapeutic option for treating recurrent case of anti-MDA5 Ab-positive cADM.