Circulating concentrations of α- and β-chemokines in neonatal sepsis

Despite advances in neonatal care, sepsis remains a threat, in particular for premature neonates, due to immature immunologic defense. Deficient chemotaxis, an essential process in the host response to pathogens, may contribute to this vulnerability. In this study we investigated chemokine expression in septic premature and term neonates.

Seventy-one neonates with signs and symptoms suggestive of systemic infection, requiring full sepsis evaluation and treatment, formed the study group; 58 neonates without sepsis served as the control group. Serum concentrations of two α-chemokines (GRO-α and ENA-78) and two β-chemokines (RANTES and MIP-1α) were measured at day 0 and day 3-5 of infection in the study group, and on the day of inclusion in the study in the control group.

During infection, serum levels of GRO-α in the study group were higher and serum levels of RANTES were lower as compared to those of the control group (p<0.001 and p<0.001, respectively). Furthermore, levels of GRO-α were higher and levels of RANTES were lower on day 0 as compared to levels on day 3-5 (p<0.001 and p<0.001, respectively). Chemokine serum concentrations on day 3-5 in the study group did not differ significantly as compared to those of the control group. Term and preterm infants seemed to respond similarly regarding chemokine expression. No significant differences were found in serum levels of MIP-1α and ENA-78.

Our findings suggest up-regulation of GRO-α and down-regulation of RANTES at the onset of a septic episode, similar to the response pattern observed in septic adults. Both term and preterm neonates appear to have the potential to elicit a chemotactic response to infection.