Objective: Macrophage colony-stimulating factor (M-CSF) is a hematopoietic growth factor that mainly stimulates the growth, differentiation, and proliferation of cells of the monocyte-macrophage lineage. There are only limited numbers of studies about M-CSF levels in neonates, but high levels of serum M-CSF have been reported in septic and some thrombocytopenic adult patients. In this study, we investigated the serum M-CSF levels in healthy, septic, and hypoxic term neonates on the first day of life and examined the relationship of serum M-CSF levels and circulating monocyte and thrombocyte counts in these newborn infants.
Study design: Three groups were defined in this prospective study: group 1, healthy neonates with no risk factors (n = 40); group 2, neonates who had severe hypoxia (n = 20); and group 3, neonates who fulfilled the criteria for early-onset sepsis (n = 18). Blood samples were collected for complete blood cell count and serum M-CSF levels by peripheral venipuncture from each infant in the first 24 hours after birth before any medical therapy.
Results: The gestational ages and birth weights did not differ significantly between the groups. Serum M-CSF levels of the septic neonates were significantly higher than of both healthy and hypoxic neonates, but did not differ significantly between the healthy and hypoxic neonates. There was no significant correlation between serum M-CSF levels and circulating monocyte counts, but there was a significant inverse correlation between serum M-CSF levels and thrombocyte counts. When this correlation was analyzed according to groups, we determined that this inverse correlation between M-CSF levels and thrombocyte counts was especially significant in the septic neonate group, but not significant in the healthy and hypoxic neonate groups.
Conclusions: Serum M-CSF levels are significantly higher in neonates with sepsis. High serum M-CSF levels may have a possible role in the pathogenesis of thrombocytopenia in neonates with sepsis.