Effects of high-dose granulocyte colony-stimulating factor on neutrophil functions

We evaluated the effects of high-dose recombinant human granulocyte colony-stimulating factor (rhG-CSF) therapy on N-formyl-methionyl-leucyl-phenylalanine (FMLP)-induced chemotaxis and superoxide (O2-) production in neutrophils from four patients with aplastic anaemia. The FMLP-induced chemotaxis and O2- production in the neutrophils of all four patients were normal before the rhG-CSF treatment. After the administration of high-dose rhG-CSF, chemotaxis in agarose was decreased, adherence and O2- production were enhanced in all the patients. An excessive increase of neutrophils with augmented adhesiveness and oxygen radical production may be harmful. Care should be taken in regard to neutrophil toxicity when high-dose G-CSF is used clinically.