细菌感染患者外周血中性粒细胞表面CD64指数的变化

目的观察不同感染程度患者外周血中性粒细胞表面CD64的表达水平，评价CD64对诊断细菌感染的实用价值。方法将110名研究对象分为4组，即败血症组、局部感染组、病毒感染组和正常对照组。采用流式细胞仪、免疫浊度法和血液分析仪分别检测各组研究对象外周血CD64指数的表达水平、C反应蛋白（CRP）含量、白细胞（WBC）数量及中性粒细胞的百分比（Neu％）。结果败血症组CD64指数（5．12±2．10）明显高于其他3组（P〈0．001），局部感染组（2．51±1．64）与病毒感染组（1．354±0．39）、正常对照组（1．00±0．31）比较，差异有统计学意义（P〈0．001），病毒感染组与正常对照组差异无统计学意义（P〉0．05）。细菌感染组（败血症组＋局部感染组）CD64与CRP、WBC、Neu％呈正相关（r=0．81、0．46、0．43，P均〈0．05）。根据受试者工作特征（ROC）曲线，当CD64指数临界值取1．34时，敏感性为89．7％，特异性为79．8％。结论中性粒细胞表面CD64指数可以作为诊断细菌感染的敏感指标，特别是对败血症的诊断更有价值。

Change of neutrophil CD64 index in the peripheral blood of patients with bacterial infection

Objective To observe the level of neutrophil surface CD64 in the peripheral blood of patients with different degrees of bacterial infection, and evaluate the practical value of CD64 in diagnosis of bacterial infection. Methods 110 subjects were classified into four groups: sepsis, local bacterial infection, viral infection and normal control. For all subjects, the levels of the index of CD64, C reaction protein (CRP), white blood cell (WBC) and the percent of neutrophil (Neu%) in the peripheral blood were measured by automatic flow cytometry, immunoturbidimetry and haematology analyser. Results The index of CD64 in the sepsis group (5.12±2.10) was significantly higher than that in the other three groups(P<0.001), and the index of CD64 in the local bacterial infection group(2.51±1.64) was higher than that in the viral infection group(1.35±0.39) and the normal control group (1.00±0.31, P<0.001). There was no statistical difference in the viral infection group and the normal control group (P>0.05). The index of CD64 in bacterial infection group (including sepsis group and local bacterial infection) had positive correlation with CRP, WBC and Neu% (r=0.81, 0.46, 0.43, P<0.05). According to the receiver operating characteristic (ROC) curve, the best threshold in diagnosis of infection was 1.34 with the sensitivity of 89.7% and the specificity of 79.8%. Conclusions Neutrophil surface CD64 index may be a sensitive index for diagnosing bacterial infection, especially sepsis.