Treatment of systemic vasculitis with cyclophosphamide and steroids: daily oral low-dose cyclophosphamide administration after failure of a pulse intravenous high-dose regimen in four patients.

The efficacy of cyclophosphamide (CY) in the treatment of severe systemic vasculitis has been demonstrated, but its optimal administration regimen remains to be defined. The four patients described participated in prospective therapeutic trials of polyarteritis nodosa (PAN) without hepatitis B infection markers, Churg-Strauss syndrome (CSS) and Wegener's granulomatosis (WG) and received daily oral low-dose CY after failure of a monthly pulse regimen. These patients were included in this study because of failure to induce clinical remission (two patients) and relapse during the course of treatment (two patients). The results were good with initial clinical remission in three patients and stabilization in one. One patient with WG relapsed 10 months after changing therapeutics. The advantages of the different administration protocols are discussed.