不同炎症因子在血流感染诊断中的应用价值

Value of different inflammatory factors applied to diagnosing bloodstream infection

目的探讨降钙素原(PCT)、C-反应蛋白(CRP)、WBC计数和中性粒细胞百分比(N%)在血流感染诊断中的应用价值。方法选择90例血流感染患者与50例健康志愿者(对照组),根据细菌鉴定结果将血流感染患者分为革兰阳性(G^+)球菌血流感染组40例、G^+杆菌血流感染组16例、革兰阴性(C-)杆菌血流感染组27例及真菌血流感染组7例。比较5组的PCT、CRP、WBC计数和N%,采用受试者工作特征曲线分析各炎症因子对血流感染的诊断效能。分析各血流感染组PCT与CRP、WBC计数、N%的相关性。结果 (1)G^+球菌血流感染组、G^-杆菌血流感染组和真菌血流感染组的PCT水平均高于对照组(P<0.05);G^+球菌血流感染组、G^+杆菌血流感染组、G^-杆菌血流感染组和真菌血流感染组的CRP水平均高于对照组(P<0.05);G^-杆菌血流感染组的N%水平高于对照组(P<0.05);各血流感染组的WBC计数与对照组比较,差异无统计学意义(P>0.05)。(2)PCT诊断G^+球菌血流感染、G^+杆菌血流感染、G^-杆菌血流感染、真菌血流感染的曲线下面积(AUC)均>0.7,CRP及N%诊断G^+杆菌血流感染、G^-杆菌血流感染、真菌血流感染的AUC均>0.7,而WBC计数诊断各类型血流感染的AUC值都较低。(3)G^+杆菌血流感染组、G^-杆菌血流感染组、真菌血流感染组PCT水平与CRP水平呈正相关(P<0.05),G^+球菌血流感染组、G^+杆菌血流感染组PCT水平与N%呈正相关(P<0.05),各血流感染组PCT水平与WBC计数均无相关性(P>0.05)。结论 PCT检测对血流感染具有重要的诊断价值,CRP和N%检测可用于血流感染的辅助诊断,WBC计数则价值不大。

Objective To explore the value of procalcitonin（ PCT）,C-reactive protein（ CRP）,WBC count and percentage of neutrophils（ N%） applied to the diagnosis of bloodstream infection. Methods Ninety patients with bloodstream infection and 50 healthy volunteers（ control group） were enrolled. The patients with bloodstream infection were divided into gram-positive（ G~＋） coccus bloodstream infection group（ n = 40）,G~＋bacillus bloodstream infection group（ n = 16）,gram-negative（ G^-） bacillus bloodstream infection group（ n =27）and fungus bloodstream infection group（ n = 7） according to the results of bacteria identification. PCT,CRP,WBC count and N% were compared among the five groups. Receiver operating characteristic curve was used to analyze the diagnostic efficiency of each inflammatory factor for bloodstream infection. The correlation of PCT with CRP,WBC count or N% was analyzed in each bloodstream infection group.Results（ 1） The PCT levels in the G~＋coccus bloodstream infection group,G^-bacillus bloodstream infection group and fungus bloodstream infection group were statistically higher than the level in the control group（ P 0. 05）; the CRP levels in the G~＋coccus bloodstream infection group,G~＋bacillus bloodstream infection group,G^-bacillus bloodstream infection group and fungus bloodstream infection group were statistically higher than the level in the control group（ P 0. 05）; the level of N% in the G^-bacillus bloodstream infection group was higher than that in the control group（ P 0. 05）; no statistically significant difference was found in the WBC count between each bloodstream infection group and the control group（ P 0. 05）.（ 2） The area under curve（ AUC） of PCT was higher than 0. 7 for diagnosing bloodstream infection caused by G~＋cocci,G~＋bacillus,G^-bacillus or fungus,and the AUC of CRP or N% was higher than 0. 7 for diagnosing bloodstream infection caused by G~＋bacillus,G^-bacillus or fungus,but the AUC of WBC count was quite low for diagnosing all types of bloodstream infection.（ 3） The PCT level positively correlated with the CRP level in the G~＋coccus bloodstream infection group,G^-bacillus bloodstream infection group and fungus bloodstream infection group（ P 0. 05）,the PCT level positively correlated with N% in the G~＋coccus bloodstream infection group and G~＋bacillus bloodstream infection group,（ P 0. 05）,but no correlation was found between PCT level and WBC count in each bloodstream infection group（ P 0. 05）. Conclusion PCT detection obtains an important value in the diagnosis of bloodstream infection. CRP and N% detection can be applied to the auxiliary diagnosis of bloodstream infection,but WBC count is less valuable.