Background: Pulmonary arterial hypertension (PAH) and interstitial pneumonia (IP) are relatively rare complications of systemic lupus erythematosus (SLE) and are associated with a poor prognosis. Overcoming these complications is a challenge for improving the prognosis.
Case report: A 41-year-old woman was diagnosed with SLE complicated by IP at the age of 21 years and with antiphospholipid syndrome at the age of 32 years at another hospital. She had been administered prednisolone (PSL) at a dose ≥15 mg daily, as well as various immunosuppressants and antiplatelet/anticoagulation therapy. On day I of hospitalization, She presented to our emergency outpatient department with fever, marked dyspnea, and skin ulcer on the left lower leg and was admitted the same day. Chest radiography revealed marked cardiomegaly and interstitial shadow, and right heart catheterization showed elevation in the mean pulmonary arterial pressure to 47 mmHg, indicating PAH. While oxygen therapy was started, high-dose steroid therapy and mycophenolate mofetil (MMF) were administered for treatment of SLE complicated by PAH/IP, and prostacyclin (prostaglandin I2), endothelin receptor antagonist, and PDE5 inhibitor were administered for PAH. Both SLE disease activity and PAH/IP improved and were maintained with no exacerbation for 2 years. The PSL dose could eventually be reduced to 5 mg/day.
Conclusion: In SLE complicated by PAH/IP, reports on the efficacy of MMF are scarce, and our findings suggested that MMF may be a treatment option in such cases.
Keywords: Systemic lupus erythematosus; interstitial pneumonia; mycophenolate mofetil; pulmonary arterial hypertension.