Usefulness of Procalcitonin in the Diagnosis of Early Neonatal Bacterial Infection

ABSTRACT

BACKGROUND: The use of several biochemical markers has improved the diagnosis of neonatal bacterial infection, which remains an important cause of morbidity and mortality. Recently, serum procalcitonin (PCT) has been investigated as a new marker for the detection of bacterial infection. The aim of this study was to assess the usefulness of PCT in early neonatal bacterial infection and compare the diagnostic utility of PCT with that of C-reactive protein (CRP). METHODS: We retrospectively studied 216 neonates (109 full term, 107 preterm) whose PCT was measured 24 hr after birth. Thirty-five were clinically classified into an infected group, of which 17.4% had positive cultures. Clinical data, PCT, CRP, leukocyte, and neutrophil counts were evaluated. The diagnostic performance of PCT and CRP was studied using receiver operating characteristic analysis. RESULTS: Compared to the non-infected group, the infected group displayed significantly higher median PCT (0.82 vs. 12.29 ng/mL, P<0.0001) and CRP (1.0 vs. 5.0 mg/L, P<0.0001) values, but similar leukocyte and neutrophil counts. The thresholds for PCT and CRP were 2.75 ng/mL (sensitivity, 97.1%; specificity, 76.7%) and 3.1 mg/L (sensitivity, 68.6%; specificity, 83.3%), respectively. The area under the curve for PCT was 0.937 (95% confidence interval [CI], 0.896-0.965) and 0.781 for CRP (95% CI, 0.720-0.834). CONCLUSIONS: During the first 24 hr after birth, PCT is a more sensitive marker than CRP for bacterial infection and has predictive value for early neonatal bacterial infection.