FIGURE 1.

Kinetics of serum levels of S100A8/A9, CRP, and IL‐6 during neonatal sepsis in preterm infants. Serum levels of (A) S100A8/A9, (B) C‐reactive protein (CRP), and (C) interleukin 6 (IL‐6) were measured in preterm neonates during the course of neonatal sepsis (n = 41) with day 0 representing the day of first clinical suspicion of sepsis before start of antibiotic treatment and preterm infants matched for gestational and postnatal age, mode of delivery (MOD), sex, and birth weight (BW) (controls, Ctrl; n = 50). S100A8/A9 serum levels only slightly but not significantly increased at initial presentation of sepsis compared to control children due to the already high normal levels of S100A8/A9 in preterm control infants during the first 2 weeks of life (A). Levels did not change significantly in the 10 days after sepsis onset (A). In contrast, CRP and IL‐6 levels in preterm control neonates were low and within the range of normal adult values, but significantly increased in the initial days of sepsis (B and C). Bars represent medians and interquartile ranges. Significant differences were determined by Kruskal–Wallis test across all age groups and by post hoc Dunn's multiple comparison tests between subgroups (*p < 0.01, ***p < 0.0001). Dashed lines indicate mean values ± 2SD in healthy adults. (D) Receiver operating characteristic (ROC) curves for S100A8/A9, CRP, and IL‐6 demonstrate the superiority of CRP and IL‐6 over S100A8/A9 in sepsis detection at the onset of sepsis in neonates