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/microl) 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/microl, does not appear to carry a high risk of inducing a flare of the vasculitis.