This study reports on 9 patients suffering from Wegener's granulomatosis (WG) with crescentic GN and severe systemic manifestations. On admission the mean serum creatinine was 10.9 +/- 5.1 mg/dl (4-20 mg/dl); 8 patients were oliguric and required dialysis treatment. Renal biopsy showed crescents in all cases, involving 66 to 100% of glomeruli. Patients were treated with a protocol including: a plasma exchange (PE) course; methylprednisolone; cyclophosphamide; and an antithrombotic agent (defibrotide). Clinical picture and renal function progressively improved in all patients within the first 4 weeks of treatment. After 1 month serum creatinine was 2.7 +/- 0.8 mg/dl and dialysis was no longer needed in any patient. Five relapses occurred in 3 patients 12-26 months after the onset of the disease, while they were still receiving immunosuppressive treatment. At follow-up (22 to 112 months: mean 71) all patients were alive with no clinical signs of disease activity. One patient was on regular dialysis while the others had a serum creatinine of 1.2-2.8 mg/dl (mean 1.9). Our results confirm that crescentic GN associated with WG can be successfully treated even when associated with severe clinical picture and suggest that PE can contribute to control the disease without increasing immunosuppression.