降钙素原区分血流感染病原体的效果研究

Effect of procalcitonin on distinguishing different pathogens of bloodstream infection

目的研究血清降钙素原检测在鉴别血流感染病原体类型中的作用,为临床治疗提供参考依据。方法选取2015年11月1日-2016年10月31日血培养阳性的血流感染患者685例,分为革兰阳性菌、革兰阴性菌和真菌组,观察不同病原体之间降钙素原检测的差异性。结果入组118例血培养阳性的单一血流感染患者共检出病原菌118株,其中革兰阳性菌48株占40.68%、革兰阴性菌64株占54.24%和真菌6株占5.08%,三组降钙素原检测均值分别为2.46ng/ml、7.08ng/ml、1.94ng/ml,差异无统计学意义;大肠埃希菌与其他革兰阴性菌、革兰阳性菌比较,降钙素原检测值均较高,差异有统计学意义(P<0.05);经ROC曲线分析,PCT的阈值在大肠埃希菌区别其他革兰阴性菌、革兰阳性菌敏感度约为85.00%,但特异度<60.00%。结论血清降钙素原检测不能成为鉴别单纯血流感染病原体类型的指标,临床工作中应结合患者的临床表现等进行综合分析。

OBJECTIVE To analyze the function of procalcitonin（PCT）in distinguishing different types of pathogens of bloodstream infections,so as to provide references for clinical treatment.METHODS From Nov.1st 2015 to Oct.31 th 2016,685 patients with bloodstream infections proved by positive blood culture were chosen.The different levels of PCT from different pathogens and three groups including gram-positive bacteria,gram-negative bacteria and fungi groups were analyzed.RESULTS Totally 118 patients were enrolled.There were 118 strains of pathogens were detected,including 48strains（40.68%）of gram-positive bacteria,64strains（54.24%）of gramnegative bacteria and 6strains（5.08%）of fungi,and the average levels of PCT were 2.46ng/ml,7.08ng/ml,and 1.94ng/ml,respectively.However,there was no significant difference among the PCT level from the three groups.The level of PCT fromEscherichia coli was significently higher compared to other gram-negative bacteria and all gram-positive bacteria（P〈0.05）.ROC curve analysis showed that.the sensitivity was about 85.00% but the specificity was less than 60.00% when E.coli distinguished other gram-negative bacteria and gram-positive bacteria by using PCT threshold.CONCLUSIONThe PCT level cannot be an ideal marker in distinguishing different pathogens from bloodstream infections.The value of PCT should be comprehensively analyzed in conjunction with manifestation of patient in clinic.