Paradoxical drop in circulating neutrophil count following granulocyte-colony stimulating factor and stem cell factor administration in rhesus macaques.

Objective: Granulocyte colony-stimulating factor (G-CSF) is frequently used therapeutically to treat chronic or transient neutropenia and to mobilize hematopoietic stem cells. Shortly following G-CSF administration, we observed a dramatic transient drop in circulating neutrophil number. This article characterizes this effect in a rhesus macaque animal model.