白细胞介素-6在早期区别新生儿不同细菌血流感染和鉴别血培养污染的意义

Significance of interleukin-6 distinguishing neonatal bloodstream infection caused by different bacteria and identification of blood culture contamination in the early stage

目的研究血清白细胞介素-6(IL-6)浓度在早期初步区分不同细菌引起的新生儿血流感染和鉴别新生儿血培养污染的意义。方法选取2016年1月~2020年6月佛山市三水区人民医院收治的100例血流感染新生儿作为观察组,在首日治疗前检测IL-6、降钙素原(PCT)和C反应蛋白(CRP)的浓度,并同时做血培养。然后依据血培养结果将100例新生儿血流感染分为革兰氏阴性(G^-)菌组(27例)和革兰氏阳性(G^+)菌组(73例);通过进一步培养鉴定把G^+菌血流感染分为链球菌组(26例)和凝固酶阴性葡萄球菌(CNS)组(47例)。比较不同细菌组间血清IL-6、PCT和CRP浓度的差异,采用受试者工作特征(ROC)曲线分析IL-6在早期鉴别G^-菌和G^+菌引起的新生儿血流感染的性能。同期血培养污染的63例病例作为对照组,采用ROC曲线分析IL-6鉴别新生儿血培养污染的价值。结果G^-菌组的血清IL-6、PCT和CRP浓度分别为2033.0(75.0~15600.0)ng/L、4.0(0.58~18.99)ng/mL和2.89(0.51~21.4)μg/mL,G^+菌组的血清IL-6、PCT和CRP浓度分别为61.9(26.1~1066.7)ng/L、0.75(0.26~2.70)ng/mL和5.45(0.82~11.86)μg/mL,G^-菌组和G^+菌组的IL-6、PCT比较,差异有统计学意义(P<0.05),G^-菌组和G^+菌组的CRP比较,差异无统计学意义(P>0.05)。IL-6、PCT和CRP区分G^-与菌G^+菌感染的ROC曲线下面积分别为70.2%、64.9%、52.6%。链球菌组的IL-6浓度高于CNS组,差异有统计学意义(P<0.05);观察组的IL-6浓度高于对照组,差异有统计学意义(P<0.05)。IL-6、PCT和CRP鉴别血流感染和血培养污染的ROC曲线下面积分别为94.2%、91.0%和72.9%。结论IL-6浓度在早期协助鉴别G^-菌和G^+菌引起的新生儿血流感染和鉴别新生儿血培养污染有一定的价值,与PCT相仿,明显优于CRP,并且在G^+菌组中能初步区分链球菌和CNS所致的新生儿早期血流感染,为早期诊断提供依据,有利于早期治疗,挽救危重生命。

Objective To study the significance of serum interleukin-6(IL-6)concentration in distinguishing neonatal bloodstream infection caused by different bacteria and identification of neonatal blood culture contamination in the early stage.Methods A total of 100 neonates with bloodstream infections admitted to Foshan Sanshui District People′s Hospital from January 2016 to June 2020 were selected as the observation group,and IL-6,procalcitonin(PCT)and C-reactive protein were measured before the first day of treatment,and the blood culture was performed at the same time.According to the results of blood culture,100 neonates with bloodstream infections were divided into Gram-negative(G^-)bacterial group(27 cases)and Gram-positive(G^+)bacterial group(73 cases),and according to the bacterial culture identification results,the G^+bacterial group was divided into Streptococcus group(26 cases)and coagulase-negative staphylococcus(CNS)group(47 cases).The concentrations of IL-6,PCT and CRP in serum of different bacterial groups were compared.And the value of IL-6 in identification of neonatal bloodstream infection caused by G^-bacteria and G^+bacteria was analyzed by the receiver operating characteristic(ROC)curve in the early stage.The blood culture contamination cases(63 cases)were selected as the control group at the corresponding period,and the value of IL-6 in identifying neonatal blood culture contamination was analyzed by the ROC curve.Results The serum concentrations of IL-6,PCT and CRP in G^-bacteria group were 2033.0(75.0-15600.0)ng/L,4.0(0.58-18.99)ng/mL and 2.89(0.51-21.40)μg/mL,respectively,and the concentrations of serum IL-6,PCT and CRP in G^+bacteria group were 61.9(26.1-1066.7)ng/L,0.75(0.26-2.70)ng/mL and 5.45(0.82-11.86)μg/mL,respectively.There were statistically significant differences in IL-6 and PCT between the G^-bacteria group and G^+bacteria group(P<0.05),but no statistically significant difference in CRP(P>0.05).The areas under the ROC curve of IL-6,PCT and CRP in distinguishing neonatal bloodstream infection caused by G^-bacteria and G^+bacteria were 70.2%,64.9%and 52.6%,respectively.The concentration of IL-6 in the Streptococcus group was higher than that in the CNS group,with statistically significant difference(P<0.05).The concentration of IL-6 in the observation group was higher than that in the control group,with statistically significant difference(P<0.05).The areas under ROC curve of IL-6,PCT and CRP in identifying neonatal blood culture contamination were 94.2%,91.0%and 72.9%,respectively.Conclusion The concentration of IL-6 is valuable in the early identification of neonatal bloodstream infection caused by G^-bacteria and G^+bacteria and in distinguishing neonatal blood culture contamination.Its effect is similar to PCT,but obviously superior to CRP.It can preliminarily distinguish early bloodstream infection caused by Streptococcus and CNS in G^+bacteria group.It is helpful for providing the basis for early treatment,which can save critical life.