Influence of recombinant human erythropoietin on neutrophil function in premature neonates.

The in vivo influence of recombinant human erythropoietin (rhEpo) and iron on human neutrophil (PMN) antimicrobial function was assessed. A total of 21 preterm infants were randomized to receive either 200 U/kg/other day of rHuEPO+12 mg/kg/day of iron (EPO+high Fe, seven infants) or 200 U/kg/other day of rhEPO+4 mg/kg/day of iron (EPO+standard Fe, 9 infants) or 4 mg/kg/day of iron only (standard Fe, five infants). PMNs were isolated from blood of these infants 60+/-5 days after birth and from eight healthy adults. No differences between infants and adults were found in PMN random migration and chemotactic activity to N-formylmethionyl leucyl phenylalanine (FMLP), superoxide anion production in response to FMLP and phagocytosis of Staphylococcus aureus. In contrast, percentage phagocytosis was significantly lower in EPO+standard Fe as compared to both EPO+high Fe and standard Fe groups (P<0.01). This modest impairment of phagocytic activity of neonatal PMNs found in association with administration of rhEPO and standard iron may be related to consumption of iron during rhEPO-enhanced erythropoiesis.