Effects of granulocyte colony-stimulating factor and granulocyte-macrophage colony-stimulating factor on respiratory burst activity of neutrophiis in patients with myelodysplastic syndromes

Abstract

SUMMARY The superoxide (O2−-releasing capacity in response to N-fomiyl-methionyl-leucyl-phenylalanine (FMLP) and the priming effects of recombinant human granuloeyte colony-stimulating factor (rhG-CSF) and granulocyte-macrophage colony-stimulating faclor (rhGM-CSF) on FMLP-induced O2− release were investigated in neutrophils from 14 patients with myelodysplastic syndromes (MDS). The O2− -releasing capacity in MDS neutrophils varied from patient to patient. As compared with normal neutJ-ophils. the O2−-releasing capacity in MDS neutrophils was increased in 9/14 patients, nonnal in three patients and decreased in two patients. There was no close relationship between the O2−-releasing capacity and the peripheral blood neutrophil count or the plasma concentration of C-reactive protein. The priming of neutrophils by rhG-CSF was not observed in five patients, whereas rhGM-CSF primed neutrophils from all patients. The priming eflect of rhGM-CSF was consistently greater than that of rhG-CSF in each patient. The intravenous administration of rhG-CSF (300 μg/body) to two MDS patients showed an increase in the peripheral blood neutrophil count and enhancement of neutrophil O2 release. These findings demonstrate that the neutrophil O2−-releasing capacity in MDS varies from patient to patient and is not always impaired, and that rhGM-CSF is able to prime neutrophils which never respond to rhG-CSF.