RESUMO
BACKGROUND: The aim of this study was to determine whether neutrophil CD64 (nCD64) combined with procalcitonin (PCT), C-reactive protein (CRP) and white blood cell count (WBC) can increase the sensitivity and accuracy of neonatal sepsis diagnosis. METHODS: The serum levels of nCD64, CRP, PCT and WBC were detected in 60 patients with neonatal sepsis and 60 patients with non-sepsis. Sensitivity, specificity, positive and negative predictive values, receiver operating characteristic (ROC) area under the curve (AUC), and logistic regression analysis were performed to evaluate the diagnostic value of these markers on neonatal sepsis. RESULTS: Serum levels of nCD64, PCT, CRP and WBC were higher in the sepsis group than non-sepsis group (p<0.001). The sensitivities of nCD64, PCT, CRP and WBC at the recommended cut-off level for all infants were 79.5%, 68.2%, 38.6% and 52.3%, respectively. The best combination was nCD64 and PCT, which obtained sensitivity of 90.9%, largest AUC of 0.922, and a negative predictive value of 89.2%. However by using an optimal cut-off value, the sensitivities of all four biomarkers for the diagnosis of neonatal sepsis were increased to 95.5%. Except for WBC, the birth weight and gestational age had no effects on the diagnostic value of these serum biomarkers. CONCLUSIONS: nCD64 and PCT are better diagnostic biomarkers for early diagnosis of neonatal sepsis as compared to CRP. With the help of optimal cut-off value based on ROC curve and logistic regression analysis, the combination of these biomarkers could improve the sensitivity for the diagnosis of suspected late-onset neonatal sepsis based on common serum biomarkers.