降钙素原定量检测在儿童血流感染病原菌鉴别诊断中的应用

Quantitative Detection of Procalcitonin in Differential Diagnosis of Pathogenic Bacteria in Children with Bloodstream Infection

目的:探讨降钙素原(PCT)定量检测在儿童血流感染病原菌鉴别诊断中的应用价值。方法:回顾性分析2013年3月至2018年3月我院收治的血培养阳性血流感染患儿250例及血培养阴性患儿76例的临床资料,比较PCT浓度在不同类型病原菌血流感染之间的差异,运用ROC评价PCT的诊断效能。结果:250例血培养阳性患儿共分离出G^-菌110株、G^+菌119株、真菌21株。G^-菌以大肠埃希菌(35株)最为多见; G^+菌以金黄色葡萄球菌(37株)最为多见;真菌以白色念珠菌(14株)最为多见。不同感染类型患儿PCT血清浓度比较差异有统计学意义(Hc=13. 568,P均<0. 01)。G^-菌组、G^+菌组、真菌组PCT浓度高于血培养阴性组(P<0. 01),G^-菌组的PCT浓度高于G^+菌组和真菌组(P<0. 01)。不同PCT浓度G^-菌组和G^+菌组阳性率比较差异有统计学意义(χ~2=27. 307及19. 649,P均<0. 01),且两组患儿血清PCT浓度在<0. 5 ng/mL、0. 5～10. 0 ng/mL、> 10～50 ng/mL分布人数方面比较差异有统计学意义(P<0. 05)。ROC分析显示,PCT鉴别G^-菌血流感染的AUC为0. 792。以1. 09 ng/mL为截断点,敏感度为61. 9%,特异度为82. 7%,约登指数为44. 6%。结论:PCT鉴别G^-菌血流感染的价值较高,以1. 09 ng/mL为截断点,诊断性能较好。

Objective:To investigate the clinical application value of quantitative detection of procalcitonin(PCT)in differential diagnosis of pathogenic bacteria in children with bloodstream infection.Methods:The clinical data of 250 children with positive blood culture bloodstream infection and 76 children with negative blood culture admitted into our hospital from Mar.2013 to Mar.2018 were retrospectively analyzed.Differences of PCT concentration between different types of pathogen bloodstream infection were compared,and the ROC curve was used to evaluate the diagnostic efficiency of PCT.Results:In 250 children with bloodstream infection,110 cases were infected with G^-bacteria,119 cases with G^+bacteria,21 cases with fungi.Escherichia coli(35 strains)was the most common in G^+bacteria,Staphylococcus aureus(37 strains)was the most common in G^+bacteria and Candida albicans(14 strains)was the most common in fungi.The median difference in PCT serum concentrations in children with different infection types was statistically significant(Hc=13.568,P<0.01).The PCT serum concentrations in G^-bacteria group,G^+bacteria group,fungi group was higher than that in blood culture negative group(P<0.01),the PCT serum concentrations in G^-bacteria group was higher than that in G^+bacteria group and fungi group(P<0.01).The positive rates of G^-bacteria group and G^+bacteria group were significantly different among different PCT serum concentrations(χ^2=27.307,19.649,P<0.01).There were significant differences in the distribution of number of cases in<0.5 ng/mL,from 0.5 to 10.0 ng/mL,and>10 to 50 ng/mL between two groups(P<0.05).ROC curve analysis showed that the AUC was0.792,with 1.09 ng/mL as the cut-off point,the sensitivity was 61.9%,the specificity was 82.7%,and the yoden index was 44.6%.Conclusion:The value of detection of PCT for G^-bacteria bloodstream infection is higher,with 1.09 ng/mL as the cut-off point,and the diagnostic performance is better.