Abstract:

Objective To investigate the roles of procalcitonin （PCT） and C-reactive protein （CRP） in the diagnosis of neonatal bloodstream infection,and to provide a reference for the early diagnosis and antibiotic treatment of bloodstream infection. Methods A total of 55 patients with blood culturing positive were enrolled as experimental group,and they were determined for PCT and CRP. Totally,55 cases with blood culturing negative confirmed by clinical diagnosis in the same period were enrolled as control group. The experimental group were sub-classified according to Gram-positive and Gram-negative bacteria,and the difference of PCT and CRP levels among these groups was compared. The efficiencies of PCT and CRP for the diagnosis of neonatal bloodstream infection were analyzed and compared according to receiver operating characteristic （ROC）curve. Results In the experimental group,PCT was 0.65（0.25-7.00） ng/mL,which was higher than that in control group [0.17（0.12-0.24） ng/mL]（P=0.000）. CRP in the experimental group was 10.97（1.04-23.82） mg/L,and that in control group was 2.49（0.62-9.62） mg/L （P=0.002）. The PCT in Gram-negative bacteria was higher than that in Gram-positive bacteria （P<0.05）,and CRP level had no statistical significance between the 2 subgroups （P>0.05）. ROC curve analysis showed that when PCT was 0.245 ng/mL as the cut-off value of neonatal bloodstream infection,the sensitivity,specificity,positive predictive value, negative predictive value and accuracy were 76.4%,78.2%,77.8%,76.8% and 77.3%. The area under curve （AUC） was 0.830. The sensitivity,specificity,positive predictive value,negative predictive value and accuracy were 56.4%,72.7%,67.4%,62.5% and 64.5%,respectively,when CRP was 9.185 mg/L as the cut-off value of neonatal bloodstream infection. The AUC was 0.669. Conclusions The determinations of PCT and CRP play roles in diagnosing neonatal bloodstream infection. The sensitivity and specificity of PCT determination are superior to those of CRP determination. PCT level is high in bloodstream infection patients infected with Gram-negative bacteria than that with Gram-positive bacteria.

Key words: Procalcitonin, C-reactive protein, Gram-negative bacterium, Gram-positive bacterium, Bloodstream infection