Evaluation of CD64 Expression on Peripheral Blood Neutrophils for Early Detection of Neonatal Sepsis

Background: Neonatal sepsis is a life-threatening disease with an incidence of 1 to 10 per 1000 live births and a mortality rate of 15% to 50%. The clinical signs are non-specific and indistinguishable from those caused by a variety of neonatal noninfectious disorders. Objective: The aim of this study was to determine the importance of CD64 expression (FcgRI), a neutrophil surface marker, in early diagnosis of neonatal sepsis. Methods: The studied population comprised of 65 neonates with gestational ages of 27 to 38 weeks, suspected of having sepsis in the first 28 days of life and 12 healthy neonates with physiologic hyperbilirubinemia. One ml of whole blood was obtained to determine CD64 expression on peripheral blood neutrophils by flow cytometry. Results: CD64 expression was significantly higher in the group with sepsis than the control groups (P < 0.001). Sensitivity and specificity of CD64 were 92.3% and 100%, respectively. The negative and positive predictive values of CD64 for identifying sepsis were 100% and 88%, respectively. Conclusion: A change in cell surface expression of CD64 on peripheral blood neutrophils may be considered as a sensitive marker for detection of neonatal sepsis if used in combination with other laboratory parameters.