Granulocyte colony-stimulating factor (G-CSF) is a naturally occurring glycosylated protein that was originally identified as a granulopoietic growth factor. It has been shown that G-CSF stimulates the proliferation and maturation of neutrophil precursor cells as well as increases such neutrophil functions as chemotaxis, phagocytosis, and bactericidal activity. G-CSF has drawn recent attention as a therapeutic drug for sepsis, because studies show that G-CSF not only selectively stimulates the proliferation of neutrophils but also plays an important role as a multipotent modulator of acute inflammation.
We previously reported an increased serum G-CSF concentration concomitant with an elevated absolute neutrophil count showing a left shift toward more immature forms, and that neutrophil phagocytic and bactericidal activity is maintained in patients with trauma or sepsis. We suggested that G-CSF plays an important role in neutrophil maturation and the maintenance of neutrophil function in inflammatory response associated with trauma and sepsis.
We also investigated the clinical effects of recombinant human G-CSF (rhG-CSF) administration in patients with sepsis who lack appropriate neutrophilia. We concluded that rhG-CSF administration attenuates inflammatory responses without inducing tissue injury. In addition, we found the difference in responses after rhG-CSF in each patients with sepsis. In the good response group, rhG-CSF administration markedly improved the severity of illness and produced a good outcome. The endogenous G-CSF level in blood showed lower than that in the poor response patients before rhG-CSF administration. Immature neutrophils was significantly higher in poor response group than those in good response group. Those results suggest that rhG-CSF was effective in septic patients with a low percentage of immature neutrophils and insufficient endogenous G-CSF.
Some recent reports, however, have suggested that rhG-CSF treatment in patients receiving cytotoxins can be associated with pulmonary toxicity. However, we revealed that rhG-CSF causes leukocyte stiffness but attenuates inflammatory response without inducing lung injury in septic patients.
This review will provide an overview of our current understanding of the role of G-CSF as an anti-inflammatory modulator in patients with sepsis.
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