Successful bosentan therapy in a case of pulmonary arterial hypertention developed during immunosuppressive therapy for lupus nephritis.

We report a 43-year-old female who developed pulmonary arterial hypertension (PAH) during intensive immunosuppressive therapy for systematic lupus erythematosus (SLE). She was diagnosed as SLE at the age of 32 years based on serological and hematological abnormalities, oral ulcers, and facial erythema. She experienced frequent flare-ups of disseminated discoid lupus between the ages of 33 and 36 years and developed immune thrombocytopenia at the age of 39 years. In 2007 when she was 43 years old, she developed lupus nephritis (LN) with elevated serum anti-double stranded DNA antibodies and urine protein of less than 1 g/day. Combination therapy for the LN with 35 mg/day prednisolone and intravenous cyclophosphamide (IVCY) led to renal remission. After the seventh monthly session of IVCY, she developed dyspnea on exertion. PAH was diagnosed based on enlarged main pulmonary arteries on the chest x-ray, right ventricular outflow and a peak tricuspid regurgitant pressure gradient exceeding 45 mmHg on echocardiography, an elevated plasma brain natriuretic peptide (BNP) level of 260 pg/ml, the exclusion of pulmonary thromboembolism, and no lung fibrosis. The PAH was treated successfully with bosentan. At present the tricuspid regurgitation has disappeared, and the plasma BNP level has normalized.