Myeloid colony-stimulating factors: use in the newborn

Bacterial and fungal sepsis are major causes of morbidity and mortality in the newborn. Multiple factors contribute to this increased susceptibility to infection, including quantitative and qualitative neutrophil defects, with a reduction in neutrophil number and function. Neutropenia in the newborn may occur in association with sepsis and has a poor prognosis. In addition to antibiotic therapy and supportive care, granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF) have been used to reduce morbidity and mortality. Granulocyte CSF is the physiological regulator of neutrophil production and function. Administration of G-CSF results in increased neutrophil production and counts and improved neutrophil function. Several studies of animal and human newborns having neutropenia or suspected sepsis investigated the use of G-CSF and GM-CSF to elevate neutrophil counts and reduce morbidity and mortality in this population. Results of small clinical trials using G-CSF and GM-CSF in very low-birth-weight infants having neutropenia show increased neutrophil counts and a reduced incidence of sepsis during the neonatal period. Despite these promising early results, further studies of the safety and efficacy of G-CSF and GM-CSF administration in neonates are required before their routine use can be recommended as either prophylaxis or treatment for neonatal sepsis.