Renal crisis due to intimal hyperplasia in a patient with mixed connective tissue disease (MCTD) accompanied by pulmonary hypertension.

We report the case of a young female patient with mixed connective tissue disease (MCTD). She had marked pulmonary hypertension (PH) without lung fibrosis. She developed renal crisis after delivery by caesarean section. Renal biopsy revealed severe renal intimal hyperplasia with mild glomerular changes. The combination of intravenous pulse high-dose corticosteroid and cyclophosphamide (CPA) infusion and subsequent corticosteroid oral administration rescued her from renal crisis. This suggests that the possibility of co-incident renal intimal hyperplasia should be considered in patients with MCTD accompanied by PH. In addition, there might be some clinical benefit in combining high-dose corticosteroid with CPA infusion in the treatment of renal crisis due to intimal hyperplasia in MCTD.