Interleukin-6 (IL-6) and soluble receptors for interleukin-2 [sIL-2R) in the diagnosis of early severe infection in the critically ill newborns

The aim of our study was to evaluate the diagnostic accuracy of serial dete rmination of interleukin-6 (IL-6) and soluble receptors of interleukin-2 (s IL-2R) in the diagnosis of early infection in the critically ill newborns a nd compare it with the routinely used C-reactive protein (CRP). Fourty-six critically ill newborns (median age 8 h, range 1 - 96 h), treated at the mu ltidisciplinary intensive care unit, Division for Paediatric Surgery and In tensive Care, University Medical Centre Ljubljana, were included in the stu dy. Newborns were divided into three groups: group I microbiologically conf irmed severe infection (n = 14), group II suspected but not confirmed infec tion (n = 12) and group III respiratory distress syndrome without laborator y signs of infection. Serum concentrations of IL-6, sIL-2R and CRP were det ermined on admission and at 12 and 24 h after admission. On admission the c oncentrations of IL-6 and sIL-2R were significantly higher in group I than in group III, but there was no difference between groups I and II. On admis sion area under receiver operating characteristic (ROC) curve for IL-6 was 0.756, for IL-2R 0.821 and for CRP 0.799. Repeated determination at 12 h im proved diagnostic accuracy for sIL-R and CRP but not for IL-6.