Implication of serum copper level, serum zinc level, and copper to zinc ratio in neonatal sepsis.

Background: Zinc and copper are trace elements that have important roles in the function of the immune system. We aimed to compare serum zinc and copper levels in neonates with and without neonatal sepsis.

Methods: This case-control study examined 54 newborns with sepsis and 54 matched healthy controls admitted to the neonatal intensive care unit of Children's Hospital, Bandar Abbas, Iran. Neonates with the diagnosis of sepsis were regarded as cases and those admitted for other reasons were regarded as controls. Maternal and neonatal serum zinc and copper were measured on admission. Copper, zinc, and copper/zinc ratio differences between case and control groups were analyzed.

Results: Neonatal zinc levels were significantly lower in the sepsis group versus controls (88.65 ± 40.64 vs 143.48 ± 69.57μg/dL, p < 0.001). Sepsis group mothers had lower zinc (66.04 vs 83.37μg/dL, p = 0.008) and copper (124.09 vs 157.74μg/dL, p < 0.001). Neonatal copper levels were slightly lower in the sepsis group. Copper/zinc ratio was significantly higher in the sepsis group (p < 0.001). In the sepsis group, the interval to the resolution of sepsis symptoms was significantly shorter in neonates with excess compared to sufficient copper levels (P = 0.023).

Conclusions: Serum copper and zinc levels have an important role in the immune system's response to the infection. Neonatal serum copper at levels higher than normal can lead to significantly shorter hospital stay. Also, higher Cu/Zn ratios can be found in neonatal sepsis, suggesting the potential utility of this index in the diagnosis of sepsis.