Interleukin-8 as a diagnostic marker of neonatal sepsis

ABSTRACT

Early diagnosis of sepsis in the neonate is often difficult as symptoms and signs are usually non-specific and there are cases that are clinically suggestive of sepsis with negative blood culture. So we should try to find out diagnostic markers to diagnose neonatal sepsis very early. The aim of this study was to evaluate plasma IL-8 as a predictor of neonatal sepsis to facilitate early diagnosis and initiation of appropriate therapy. This study comprised 54 full-term neonates divided into 2 groups; group I included 24 neonates with proven sepsis diagnosed clinically and by positive blood culture. Group II included 30 neonates with suspected or possible infection [they had 2 or fewer clinical signs of sepsis +/- positive CRP with a high risk factor of infection and negative blood culture]. Thirty healthy age and sex matched full-term newborns were studied as controls. After history taking and clinical examination, the following laboratory investigations were performed complete blood count, CRP [latex agglutination], blood culture and sensitivity and estimation of IL-8 by ELISA technique The 30 patients with suspected infection were followed up clinically and CRP as well as blood culture were repeated after 48 hours. Patients who developed sepsis later on as evidenced clinically and by laboratory investigations including positive blood culture were considered as patients with early sepsis at the time of admission. Plasma IL-8 of neonates with proven sepsis [1794.38 +/- 1816 9 pg/ml] or early sepsis [229.16 +/- 221.02 pg/ml] was significantly higher than of the control group [35.53 +/- 17.8 pg/ml]. IL-8 had a sensitivity of 100% for sepsis [either at its early or late stages] as it was elevated in all patients with proven and early sepsis. The sensitivity of CRP for diagnosing neonatal sepsis before the evolution of overt clinical manifestations was 50% only. In addition, IL-8 had an excellent negative predictive value [100%] for early sepsis. IL-8 was significantly elevated in non-survivor neonates with sepsis when compared to the survivors indicating that high IL-8 values are associated with poor prognosis. In conclusion, IL-8 is a highly sensitive marker for diagnosing neonatal sepsis at its early stage. Also, it had an excellent negative predictive value [100%] thus it facilitates the exclusion of the infection in high-risk neonates to avoid the unnecessary antibiotic use. In addition, IL-8 is a useful prognostic marker of neonatal sepsis This highlights the importance of our recommendation of adding IL-8 to the laboratory investigations performed in neonatal sepsis especially in suspected cases