PCT,IL-6及PLT对于鉴定血流感染病原菌的价值研究

Study on the Value of PCT,IL-6 and PLT in Identifying Pathogens of Bloodstream Infection

目的:探讨降钙素原(PCT)、白细胞介素-6(IL-6)及血小板(PLT)在鉴别血流感染致病菌类型中的临床应用价值。方法:回顾性分析2019-2020年我院住院治疗的血流感染病例,根据血培养结果将其分为革兰氏阳性菌(G+)组和革兰氏阴性菌(G-)组,比较两组血清PCT、PLT、IL-6水平的差异,同时绘制ROC曲线并计算出各指标的诊断效能。结果:革兰氏阴性菌组的血清PCT、IL-6水平均明显高于革兰氏阳性菌组(P<0.05);两组PLT水平比较差异无统计学意义(P>0.05);根据ROC曲线,将PCT界值设定为3.63 ng/mL时,血清PCT水平区分G-菌与G+菌所致血流感染的灵敏度为88%,特异度为50%, ROC曲线下面积为0.674,95%可信区间为0.527~0.821 (P<0.01)。将IL-6界值设定为261.74 ng/mL时,血清IL-6水平区分G-菌与G+菌所致血流感染的灵敏度为84%,特异度为75%,ROC曲线下面积为0.838,95%可信区间为0.723~0.953 (P<0.01)。结论:血清PCT和IL-6水平检测对鉴别革兰氏阴性菌和革兰氏阳性菌所致血流感染有一定的临床价值,但PLT不能反映血流感染细菌类型的差异。

Objective To investigate the clinical application value of procalcitonin(PCT),interleukin-6(IL-6)and platelet(PLT)in the identification of pathogenic bacteria in bloodstream infection.Methods Retrospective analysis was performed on hospitalized cases of bloodstream infection in our hospital from 2019 to 2020.According to the results of blood culture,they were divided into the Gram-positive bacteria(G+)group and the Gram-negative bacteria(G-)group.The differences of serum PCT,PLT and IL-6 levels between the two groups were compared.Meanwhile,the ROC curve was drawn and the diagnostic efficiency of each index was calculated.Results The serum PCT and IL-6 levels in gram-nega⁃tive bacteria group were significantly higher than those in gram-negative positive bacteria group(P<0.05).,and the com⁃parison of the two groups'PLT levels was not statistically significant(P>0.05).According to the ROC curve,when the PCT cut-off value was set to 3.63 ng/mL,the sensitivity of the serum PCT level to distinguish bloodstream infections caused by G-bacteria and G+bacteria was 88%,the specificity was 50%,the area under ROC curve was 0.674 and 95%confidence interval was 0.527~0.821(P<0.01).When the IL-6 cut-off value was set to 261.74 ng/mL,the sensitivity of serum IL-6 levels to distinguish bloodstream infections caused by G-bacteria and G+bacteria was 84%,the specificity was 75%,and the area under the ROC curve was 0.838,and the 95%confidence interval was 0.723~0.953(P<0.01).Con⁃clusion The detection of serum PCT and IL-6 levels has certain clinical value in differentiating bloodstream infection caused by Gram negative bacteria and Gram positive bacteria,but PLT can not reflect the difference of bacterial types in bloodstream infection.