降钙素原、血小板计数联合检测对血流感染的诊断价值

Diagnostic value of combined detection of procalcitonin and platelet count for bloodstream infection

目的分析降钙素原(PCT)、血小板计数(PLT)在血流感染中的诊断价值。方法收集2016年5月至2019年1月该院收治的219例血流感染血培养阳性患者(研究组)血液,分别在Back/Alert 3D血培养仪中进行需氧和厌氧培养,在Mindray Auto Hematology Analyzer BC-5800血细胞分析仪中检测PLT,运用化学发光法检测PCT,根据双侧双瓶血培养结果将研究组患者进一步分为革兰阳性菌(G^+)组(72例)和革兰阴性菌(G^-)组(147例)。同时期健康体检人员93例纳入对照组,分别检测PCT、PLT。结果G^+组PCT水平明显低于G^-组,差异有统计学意义(P<0.05)。G^+组与G^-组PLT比较,差异无统计学意义(P>0.05)。与对照组比较,G^+组与G^-组PCT明显升高,PLT明显降低,差异均有统计学意义(P<0.05)。G^+组PCT为0.5~10.0 ng/mL的比例明显多于G^-组,G^-组PCT≥10.0 ng/mL的比例明显多于G+组,差异有统计学意义(P<0.05)。PCT水平越高,PLT越低,PCT与PLT呈负相关(r=-0.367)。PCT≥11.38 ng/mL,PLT≤66.5×10^9/L为二者诊断G-感染的cut-off值,二者共同诊断G^-感染的特异度为80.7%,阳性预测值为83.3%。结论联合检测PCT和PLT对诊断G^-的血流感染具有指导意义。

Objective To study the value of procalcitonin(PCT)concentration and platelet count(PLT)in bloodstream infection.Methods A total of 219 blood samples were collected from blood culture-positive patients(study group)from May 2016 to January 2019.The blood samples were subjected to aerobic and anaerobic culture in Back/Alert 3D blood culture apparatus.PLT was measured by Mindray Auto Hematology Analyzer BC-5800.Moreover,the chemiluminescence method was used to detect PCT concentration.According to the results of bilateral double bottle blood culture,the patients in the study group were further divided into the gram positive bacteria(G^+)group(72 cases)and the gram negative bacteria(G^-)group(147 cases).A total of 93 healthy examiners in the same period were collected in control group and tested for PCT and PLT.Results The PCT level of G^+group was significantly lower than that of G-group,and the difference was statistically significant(P<0.05).There was no statistically significant difference on PLT between G^+group and G^-group(P>0.05).Compared with the control group,PCT increased significantly and PLT decreased significantly in G^+group and G^-group,with statistically significant differences(P<0.05).The ratio with PCT of 0.5-10.0 ng/mL in the G^+group was significantly higher than that in the G^-group,and the ratio with PCT≥10.0 ng/mL in the G^-group was significantly higher than that in the G^+group,with statistically significant differences(P<0.05)The higher the PCT level was,the less the PLT was,and the PCT negatively correlated with the PLT,with the correlation coefficient(r)was-0.367.PCT≥11.38 ng/mL and PLT≤66.5×10^9/L were the cut-off values for the diagnosis of G^-infection,and the specificity of the combine detection of PCT and PLT for diagnosis of G^-infection was 80.7%and the positive predictive value was 83.3%.Conclusion Combined detection of PCT and PLT is significance for the diagnosis of bloodstream infection of G^-.