Production of granulocyte colony-stimulating factor in vitro by monocytes from preterm and term neonates

We postulated that defective generation of granulocyte col-ony-stimulating factor (G-CSF) by cells of newborn infants might underlie their deficiencies in upregulating neutrophil production and function during bacterial infection. To test this, we isolated monocytes from the blood of preterm neo-nates, term neonates, and adults and, after stimulation with various concentrations of interleukin-I a (IL-1 a) or lipo-polysaccharide (LPS), quantified G-CSF concentrations in cell supernatants and G-CSF mRNA in cell lysates. When stimulated with plateau concentrations of IL- la for 24 hours, G-CSF concentrations were higher in supernatants of adult cells (8,699 f 5,529 pg / l O6 monocytes) than in those from term infants (2,557 f 442 pg, P <.05) or from preterm infants (879 f 348 pg, P <.05 Y adults). When stimulated with plateau concentrations of LPS, su