Childhood onset cyclic neutropenia: G-CSF therapy restores neutrophil count but does not influence superoxide anion and cytokine release by neutrophils.

In this paper we describe the case of a 16-year-old boy with childhood onset cyclic neutropenia (CN) with a 21 d cycle who was successfully treated with recombinant granulocyte-colony stimulating factor (G-CSF). Cyclic therapy with G-CSF (5 micrograms/kg/d s.c. for 1 week every 21 d) maintained peripheral neutrophil count above the normal range, reduced the incidence of severe infections and significantly improved the patient's performance status throughout an 18-month follow-up. Phenotypic analysis of circulating lymphocytes demonstrated that G-CSF treatment does not modify the phenotypic profile of circulating B, T and NK cell populations. Circulating neutrophils released normal amounts of cytokines (including IL-1 beta, IL-8, TNF alpha) and superoxide anion during G-CSF therapy.