Granulocyte‐Macrophage Colony‐Stimulating Factor Induces Activation and Restores Respiratory Burst Activity in Monocytes from Septic Patients

Monocyte activation in response to recombinant human granulocyte-macrophage colony-stimulating factor (GM-CSF) was examined in vitro in septic shock patients. These monocytes exhibited a greater respiratory burst activity than monocytes from healthy subjects; the response to secondary stimulation with bacterial stimuli was attenuated. GM-CSF restored the ability of monocytes to respond appropriately to secondary stimulation. Expression of certain integrin adhesion molecules, L-selectin, and Fcgamma receptors was increased on monocytes of septic shock patients; expression of CD11c was reduced. GM-CSF up-regulated integrin expression and decreased L-selectin, FcgammaRII, and FcgammaRIII expression. Septic patients exhibited greater biologic activity of monocyte tissue factor than did healthy subjects. Priming monocytes with GM-CSF accelerated tissue factor activation following stimulation with lipopolysaccharide and bacterial culture supernatant. Certain parameters of monocyte function may be restored by exposure to GM-CSF. This benefit may be offset by an increase in monocyte procoagulant activity.