Granulocyte colony-stimulating factor treatment for cyclophosphamide- induced severe neutropenia in Wegener's granulomatosis

Objective. To examine the efficacy and safety of recombinant human granulocyte colony-stimulating factor (rHuG-CSF) in the treatment of cyclophosphamide (CYC)-induced severe neutropenia (<1,000 neutrophils/μl) in patients with generalized Wegener's granulomatosis (WG). Methods. Six WG patients with severe neutropenia due to CYC treatment (group A) were given short-term dosages of rHuG-CSF. Treatment response in these 6 patients was compared with that in 6 WG patients who were matched for age, sex, disease status, and prior treatment and who received supportive treatment only (group B). Results. The duration of severe neutropenia was significantly shorter in group A patients (4.0 ± 0.8 days) than in group B patients (9.0 ± 1.3 days; P = 0.03). This was accompanied by fewer bacterial infections (2 versus 4) and fewer nonbacterial infections (0 versus 3) in group A compared with group B patients. Treatment with rHuG-CSF was well tolerated and, notably, no disease flare occurred during treatment and up to 4-6 months after rHuG-CSF administration. Conclusion. Short-term, low-dose rHuG-CSF treatment can substantially shorten the duration of CYC-induced neutropenia and appears to confer significant clinical benefit. Such treatment, aimed at raising the neutrophil count above 1,000/μl, does not appear to carry a high risk of inducing a flare of the vasculitis.