Objective: To explore the significance of interleukin-6 (IL-6) and IL-8 in the diagnosis of neonatal sepsis.
Methods: This was a prospective study conducted between August 2014 and February 2015. A total of 140 neonates who were suspected infectious were enrolled and classified into a sepsis group (n=49) and a local infection group (n=91). Sixty-one neonates who were non-infectious served as the control group. Serum levels of IL-6 and IL-8 were measured before treatment and 3 days after treatment. The value of serum IL-6 and IL-8 for the diagnosis of neonatal sepsis was assessed by receiver operating characteristic (ROC) curve analysis.
Results: Before treatment, serum levels of IL-6 and IL-8 in the sepsis group were higher than those in the local infection and control groups (P<0.05), and the local infection group had higher serum levels of IL-6 and IL-8 than the control group (P<0.05). After three days of treatment, the serum IL-6 level in the sepsis group remained higher than that in the local infection and control groups (P<0.05), and the local infection group had higher serum level of IL-6 than the control group (P<0.05). There was no significant difference in the serum IL-8 level among the three groups. According to the ROC curve, when the cut-off value of serum IL-6 was 32 pg/mL, the sensitivity, specificity and accuracy of serum IL-6 for the diagnosis of neonatal sepsis were 87.8%, 79.6% and 81.6% respectively; when the cut-off value of serum IL-8 was 54 pg/mL, the sensitivity, specificity and accuracy of serum IL-6 for the diagnosis of neonatal sepsis were 77.6%, 63.8% and 67.2% respectively. With the combination of serum IL-6 and IL-8 levels, the sensitivity, specificity and accuracy for the diagnosis of neonatal sepsis were 71.4%, 86.2% and 82.6% respectively.
Conclusions: IL-6 and IL-8 participate in the inflammatory response and the serum levels of both vary with the severity of infection. The diagnostic value of IL-6 for neonatal sepsis is higher than IL-8. The combined detection of serum levels IL-6 and IL-8 may increase the accuracy of diagnosis of neonatal sepsis.