Extended-Release Tofacitinib Therapy for a MDA5 Antibody-Positive Amyopathic Dermatomyositis Patient with Early-Stage Interstitial Lung Disease

Introduction: In East Asia, more than half of patients with amyopathic dermatomyositis (ADM) have interstitial lung disease (ILD). There is up to 50% 6-month mortality in MDA5-positive ILD refractory to corticosteroid (CS) combined with immunosuppressant therapy. Patient Details: A 39-year-old local woman had a 1-month history of reddish-purple discoloration around the eyelids (heliotrope rash), and erythematous areas on the upper back and posterior neck (shawl sign) as well as on the front of her chest (V sign), followed by dry cough and mild dyspnea for 1 week. She had normal muscle strength, muscle-enzyme concentrations, and muscular magnetic resonance images. Laboratory tests showed hypoxemia, increased ferritin and CRP levels, and positive MDA5 antibodies. High-resolution chest computed tomography revealed bilateral ground-glass opacity. She received a diagnosis of anti-MDA5-positive ADM with early-stage ILD. Intervention: Pulse methylprednisolone and cyclophosphamide therapies were initiated, followed by high-dose CS treatment. Immediate-release twice-daily 5 mg tofacitinib (Tof) has been demonstrated to be effective induction therapy for early-stage ILD in anti-MDA5-positive ADM. Owing to the patient’s preference for once-daily therapy, 11 mg extended-release Tof was prescribed 4 weeks after starting the initial pulse CS treatment for ILD. Outcomes: Respiratory symptoms and cutaneous manifestations were absent and the use of CS spared 5 months after initiating Tof therapy. Laboratory examinations exhibited normalized ferritin/oxygen levels, and chest images displayed completely resolved pulmonary infiltration. ILD remains under adequate control with Tof monotherapy without recurrence at 5 months. Lessons: Owing to a rapid decline in higher mortality in anti-MDA5-positive ADM patients with ILD, early detection with prompt initiation of extended-release Tof induction therapy might achieve a beneficial outcome.