Successful treatment of chronic severe neutropenia with weekly recombinant granulocyte-colony stimulating factor

Daily treatment for symptomatic chronic neutropenia with recombinant granulocyte-colony stimulating factor (rhG-CSF) filgrastim is costly and sometimes causes neutrophillia. We report the use of weekly filgrastim in a 40-year-old man with life-long symptomatic neutropenia. Baseline neutrophil counts were <1 x 10(9)/l 60% of the time, and fell below 0.5 x 10(9)/l for 7 d periods every 22 d. Following 1 year of weekly filgrastim treatment, the absolute neutrophil count was maintained > 1 x 10(9)/l (averaging 2 x 10(9)/l) and the frequency and severity of symptoms were reduced by 85%. Therefore the benefits of filgrastim for the treatment of at least one form of chronic severe neutropenia can be derived from weekly rather than daily doses.