Granulocyte Colony-Stimulating Factor for Neutropenia in Neonatal Sepsis-Reply

We appreciate Nankervis and Seguin's patient report of another neonate who apparently benefited from rhG-CSF administration during bacterial sepsis. They aptly note the main differences in the two cases, namely route and duration of cytokine administration and neutrophil count response. Each patient had a very rapid rise in the neutrophil count, likely due to the release of mature neutrophils from the bone marrow neutrophil storage pool. 1 The differences in the duration of neutrophilia in the two cases may have reflected the subcutaneous vs intravenous routes of administration (prolonged systemic uptake from a subcutaneous drug depot in our case), the total number of doses given, or both. We disagree, however, that the single granulocyte transfusion that our patient received altered the degree of neutrophilia or natural outcome of his rhG-CSF response, since transfused granulocytes have such a short life span. 2,3 While both patients received aggressive supportive care that included