流式细胞术检测CD64指数及其在诊断细菌感染中的应用

摘要

Objective To establish a determination of CD64 index by flow cytometry(FCM),and to evaluate its value in the diagnosis of bacterial infection. Methods Polymorphonuclear(PMN)CD64 mean fluorescence intensities(MFI) in 42 healthy controls,41 patients with bacterial infection and 50 patients with non-bacterial infection were determined by FCM,and CD64 indices were calculated. The level of C-reactive protein(CRP),white blood cell(WBC) count and the percentage of neutrophils(Neu%) were analyzed simultaneously. Receiver operating characteristic(ROC) curve was used to evaluate the value of CD64 index in the diagnosis of bacterial infection.Results CD64 index in bacterial infection group [3.69(2.69-5.25)] was higher than those in healthy control group [0.79(0.40-1.31),P<0.01] and non-bacterial infection group [0.52(0.40-0.93), P<0.01]. According to ROC curves,the areas under the curves in turn were CD64 index(0.964)>CRP level (0.931)> Neu%(0.815)>WBC count(0.678),and the optimal cut-off value of CD64 index was 1.84. The diagnostic sensitivity and specificity were 87.8% and 95.7%.Conclusions Compared with traditional parameters, CD64 index by FCM with high sensitivity and specificity could be used in the diagnosis of bacterial infection.%目的 建立适用于临床的流式细胞术(FCM)检测CD64指数的方法,并探讨其在细菌感染中的应用价值.方法 用FCM检测42名健康对照者、41例细菌感染患者及50例非感染患者外周血多型核白细胞(PMN)表面CD64表达的平均荧光强度(MFI)并计算CD64指数,同时对比各组的C反应蛋白(CRP)水平、白细胞(WBC)计数和中性粒细胞百分比(Neu%),绘制各指标的受试者工作特征(ROC)曲线并评价CD64指数用于诊断细菌感染的价值.结果 细菌感染组CD64指数[3.69(2.69~5.25)]明显高于健康对照组[0.79(0.40~1.31),P<0.01]和非感染组[0.52(0.40~0.93),P<0.01];根据ROC曲线分析,各指标曲线下面积CD64指数(0.964)>CRP(0.931)>Neu%(0.815)>WBC计数(0.678),CD64指数选取最佳阈值为1.84时诊断细菌感染的敏感性和特异性分别为87.8%和95.7%.结论 FCM检测的CD64指数可用作细菌感染的诊断指标,与传统指标相比较具有较高的敏感性和特异性.