Plasma concentration of granulocyte-colony-stimulating factor in neonates

We determined the plasma concentration of granulocyte-colony-stimulating factor (GCSF) and the neutrophil count in 108 infants (gestational age 23-41 weeks; birthweight 478-4935 g). The GCSF levels in the very low birthweight infants without infection were comparable to those in the full-term infants. Infants as premature as 23 weeks of gestation showed similar GCSF levels to mature neonates. GCSF levels decreased significantly by day 7 after birth. The levels were not significantly correlated with the neutrophil count. The mean plasma level of GCSF increased significantly when infection developed and was significantly higher in the infants with sepsis than in those with non-septic infections (p < 0.01). The results suggest that GCSF may be the major determinant of neutrophil kinetics both during fetal life and after birth.