Serum Interleukin-6 Levels in the Differential Diagnosis of Sepsis and Transient Tachypnea of Newborn

Objective: The aim of this study was to evaluate the role of serum interleukin-6 (IL-6) levels in the differentiation of neonatal bacterial sepsis and TTN. Material and Methods: The hospital records of 58 newborn infants with respiratory distress who were above 35 weeks of gestational age were investigated. Patients were divided into two groups. The infection group consisted of patients with proven sepsis and clinical sepsis and the other was the TTN group. Clinical findings and white blood cell count, serum C-reactive protein (CRP), IL-6 levels and the ratio of immature neutrophils to total neutrophils count (I/T) were recorded and compared between the two groups.Results: Serum CRP and IL-6 levels were found higher than the normal limits in both of the groups. However there was no significant difference between them. Duration of respiratory distress was longer and I/T ratio significantly higher in the infection group than the TTN group. The combination of IL-6 and I/T ratio yielded a sensitivity of 80%, a specificity of 48%, a positive predictive value of 44.7%, and a negative predictive value of 80%Conclusion: The I/T ratio and IL-6 may contribute to the early diagnosis of sepsis with respiratory symptoms in newborn infants but IL-6 alone cannot distinguish between TTN and sepsis.