Diagnostic value of CD64 in early detection of neonatal sepsis

Early diagnosis of neonatal sepsis is challenging because clinical picture is not specific and hard to be discriminated from that of noninfectious causes. The gold standard tool for diagnosis of neonatal sepsis is blood culture. Cluster of differentiation 64 (CD64) is a type of integral membrane glycoprotein known as Fc receptor that binds monomeric IgG with high affinity. Stimulation via CD64 leads to elevated neutrophil capacity for phagocytosis and intracellular killing of bacteria. The aim of this study was to evaluate the role of neutrophil CD64 expression for the identification of sepsis in neonates and to state its relationship with C-reactive protein (CRP). This study included 74 neonates divided into three groups: group 1, documented sepsis (26 patients with positive bacterial culture); group 2, clinical sepsis (25 patients without culture-proven sepsis with the presence of two or more clinical symptoms or signs of sepsis); and group 3, control group (twenty-three healthy neonates). CD64 was measured at admission using enzyme-linked immunosorbent assay (ELISA) kits. A cutoff value of ≥ 535.6 pg/dl can predict neonatal sepsis with 96.1% sensitivity and 91.3% specificity. Serum CD64 was significantly higher in documented and clinical sepsis groups than in control group (p = 0.001, 0.009), respectively. Also serum Cd64 was significantly higher in documented than in clinical sepsis group (p = 0.001).A positive correlation was found between CRP and CD64. This study revealed that serum levels of CD64 can be a sensitive marker for early detection of neonatal sepsis.