蔡　鲜，胡志东，余　倩，李妍淳，李　金，徐海茹（天津医科大学总医院检验科，天津　300052）



降钙素原在区分不同病原体引起血流感染的价值

蔡鲜，胡志东，余倩，李妍淳，李金，徐海茹
（天津医科大学总医院检验科，天津300052）

摘要目的：探讨降钙素原（PCT）定量检测在区分不同病原体引起的血流感染及鉴别诊断凝固酶阴性葡萄球菌（CNS）血流感染中的临床应用价值。方法：选取531例同时送检血培养及PCT患者资料进行回顾性分析。采用ROC曲线确定降钙素原的Cut-off值，采用秩和检验比较PCT在血培养阴性与阳性组间、不同病原体组间结果有无差异。采用t检验比较CNS血流感染组与血培养污染组间结果有无差异。结果：PCT区分血培养阴性与阳性、革兰氏阴性菌与革兰氏阳性菌、CNS血流感染与血培养污染的最佳截断值分别为1.31 ng/mL、16.45ng/mL、1.34 ng/mL。PCT在血培养阴性与阳性组、革兰氏阴性菌与革兰氏阳性菌组、革兰氏阴性菌与真菌组以及CNS血流感染组与血培养污染组之间差异有统计学意义（P<0.05）。结论：PCT定量检测对预判血流感染、区分革兰氏阴性菌与革兰氏阳性菌或真菌血流感染及鉴别诊断CNS引起的血流感染具有较好的应用价值。

关键词降钙素原；血流感染；定量检测；污染

Clinical evaluation on procalcitonin in identifying bloodstream infection caused by different pathogens

CAI Xian,HU Zhi-dong,YU Qian,LI Yan-chun,LI Jin,XU Hai-ru
（Department of Clinical Laboratory,General Hospital,Tianjin Medical University,Tianjin 300052,China）

Abstract Objective:To explore the clinical value of procalcitonin（PCT）levels in identifying bloodstream infection caused by different pathogens and for differentiating coagulase negative staphylococcus（CNS）bloodstream infection and contamination.Methods:Medical records of 531 patients who underwent blood culture test and PCT at the same time were retrospectively analyzed.ROC curve was used to determine the cut-off value of PCT.Nonparametric comparisons between positive and negative blood culture or multigroup comparisons were done by rank sum test.T test was applied to compare CNS bloodstream infection and blood culture contamination group.Results:The optimal cut-off values of PCT for predicting a positive blood culture,distinguishing Gram-positive（G+）bacteria and Gram-negative（G-）bacteria ,differentiating CNS bloodstream infection and contamination were 1.31 ng/mL,16.45 ng/mL ,1.34 ng/mL respectively.PCT were significantly elevated in patients whose blood cultures were positive than the patients who had negative cultures（P<0.05）.In addition,PCT was significantly higher in patients with G-bacteria than in patients with a G+bacteria or fungi（P<0.05）.It also had significant differences between CNS bloodstream infection and contamination（P<0.05）.Conclusion:PCT is highly effective in distinguishing negative and positive bacteria or fungi bloodstream infection.In addition,PCT is also good for differentiating CNS bloodstream infection and contamination.

Key words procalcitonin;bloodstream infection;quantitative detection;contamination

血流感染（blood stream infection，BSI）是指各种病原微生物和毒素侵入到血流中而导致患者出现的一种全身性感染疾病，是目前导致患者死亡的主要原因之一。凝固酶阴性葡萄球菌（coagulase negative staphylococcus aureus，CNS）是引起医院血流感染和血培养污染的重要病原体。及时区分不同病原体引起的血流感染及鉴别诊断CNS血流感染可以为临床使用抗菌药物提供依据，同时避免不必要的抗菌药物的使用和医疗费用支出，减少微生物对抗菌药物的选择压力，减轻病人的经济负担。……