不同病原体血流感染血清降钙素原水平研究

Serum procalcitonin levels in bloodstream infections caused by different pathogens

目的分析血流感染早期血清降钙素原(PCT)水平与血流感染病原体的相关性,为临床预测病原体种类提供依据。方法收集北京同仁医院2018年1月至2020年10月526份血培养阳性样本为研究对象,其中革兰阳性球菌238株、革兰阴性杆菌245株、真菌28株和厌氧菌15株,统计患者第一次血培养阳性采血时间之前24 h内血清PCT水平。通过绘制不同病原体血流感染患者PCT水平的受试者工作特征(ROC)曲线,确定预测不同病原体血流感染的PCT水平最佳截断值。结果革兰阳性球菌血流感染患者PCT水平为0.76(0.26,3.93)ng/mL,革兰阴性杆菌血流感染患者PCT水平为4.86(0.97,24.94)ng/mL,真菌血流感染患者PCT水平为0.80(0.30,1.44)ng/mL,厌氧菌血流感染患者PCT水平为2.96(2.25,5.07)ng/mL。预测革兰阳性球菌、革兰阴性杆菌、真菌、厌氧菌血流感染的PCT水平最佳截断值分别为1.38、7.83、1.22、3.76 ng/mL。结论PCT水平与不同种类病原体存在一定关系,根据PCT水平可以预测病原体的种类。

Objective To analyze the relationship between serum procalcitonin(PCT)and pathogens of bloodstream infection and to provide basis for clinical prediction of pathogen types.Methods From January 2018 to October 2020,a total of 526 blood culture positive samples in Beijing Tongren Hospital were collected as research objects,including 238 strains of Gram positive cocci,245 strains of Gram negative bacilli,28 strains of fungi and 15 strains of anaerobic bacteria.The serum PCT levels within 24 hours before the blood collection time of first blood culture positive were counted.The cut off value of PCT level for predicting bloodstream infection of different pathogens was determined by drawing the receiver operating characteristic(ROC)curve of PCT level in patients with bloodstream infection of different pathogens.Results The PCT levels were 0.76(0.26,3.93)ng/mL in patients with bloodstream infection of Gram positive cocci,4.86(0.97,24.94)ng/mL in patients with bloodstream infection of Gram negative bacilli,0.80(0.30,1.44)ng/mL in patients with bloodstream infection of fungi and 2.96(2.25,5.07)ng/mL in patients with bloodstream infection of anaerobic bacteria.The cut off values of PCT level for predicting bloodstream infection of Gram positive cocci,Gram negative bacilli,fungi and anaerobic bacteria were 1.38,7.83,1.22 and 3.76 ng/mL,respectively.Conclusion The level of PCT is related with bloodstream infection of different types of pathogens.The types of pathogens could be predicted according to the level of PCT.