Neonatal sepsis is an important cause of morbidity and mortality in newborns. The clinical signs are non-specific and indistinguishable from those caused by a variety of neonatal non-infective disorders. Specific leucocyte surface antigens are known to be expressed after inflammatory cells are activated by bacteria or their cellular products. The aim of this study was to evaluate the diagnostic value of neutrophil adherence molecules CD11b, CD64, and CD62L (l-selectin) for the early diagnosis of neonatal sepsis.
Peripheral blood samples were taken from neonates, who were classified into three groups: neonatal sepsis; non-infective disorder and healthy newborn with physiological hyperbilirubinemia. Serum C-reactive protein was quantified at the initial evaluation. Neutrophil and monocyte expressions of CD11b, CD64 and CD62L were determined by flow cytometry and presented as mean fluorescence intensity and percentage of cells showing expression of the assessed adhesion molecules. The diagnostic utilities including sensitivity, specificity, and positive and negative predictive values of each marker for predicting systemic infection were determined.
Expression of CD64 and CD11b was significantly enhanced in the group with sepsis compared with newborns with non-infective disorder and the control group.
Our data indicate that the determination of CD64 expression on neutrophils and monocytes is a useful diagnostic marker for the early diagnosis of neonatal infection and the combination of CD64, CD11b and C-reactive protein further enhances the sensitivity and negative predictive value to 100%.