Systemic lupus erythematosus and pulmonary vascular hypertension.

Although pulmonary involvement commonly occurs in systemic lupus erythematosus (SLE), pulmonary vascular hypertension has rarely been reported. Two patients with SLE had pulmonary hypertension without underlying pulmonary parenchymal or cardiac disease. The first patient's condition was initially diagnosed as primary pulmonary hypertension (PPH), and full-blown SLE subsequently developed. The second patient had well-established SLE when respiratory symptoms secondary to underlying pulmonary hypertension developed. There is a possible relationship between connective tissue diseases and PPH.