中性粒细胞CD64在儿童社区获得性肺炎诊断中的价值

目的：探讨外周血中性粒细胞CD64的表达在儿童社区获得性肺炎（CAP）诊断中的价值。方法：依据病原体不同将98例社区获得性肺炎患儿分为细菌感染组（48例）、病毒感染组（29例）以及支原体感染组（21例）；另设健康对照组（20例）。细菌感染组依据患儿的入院情况分为轻症感染组（36例）和重症感染组（12例）。采用流式细胞术检测外周血中性粒细胞CD64的表达，同时免疫比浊法检测外周血C反应蛋白（CRP）的水平。结果：治疗前细菌感染组CD64指数和CRP水平显著高于其他3组，差异有统计学意义（P<0.05）。重症组CD64指数和CRP水平较轻症组显著增高，差异有统计学意义（P<0.05）。细菌感染组经过有效的抗菌治疗后，CD64表达水平下降，和治疗前相比差异有统计学意义（P<0.05）。相关分析结果显示CD64指数与CRP呈正相关（r=0.545，P＜0.01）。 ROC曲线分析结果显示CD64、CRP最佳临界值分别为2.8和8 mg/L，CD64指数的特异性（90%）远高于CRP（74%）。结论：外周血中性粒细胞CD64测定有助于肺部细菌感染的早期诊断，并可以判断病情的严重程度及疗效。

Value of neutrophil CD64 in the diagnosis of community acquired pneumonia in children

Objective To study the clinical value of the expression of neutrophil surface CD64 in the diagnosis of community acquired pneumonia in children.Methods Ninety-eight children with community acquired pneumonia were recruited into the study and were classified into three groups according to pathogene: bacterial pneumonia(n=48),viral pneumonia(n=29) and Mycoplasmal pneumonia(n=21).Twenty healthy children were enrolled as controls.The bacterial infection group was subdivided into mild infection(n=36) and severe infection groups(n=12).The levels of peripheral blood neutrophil CD64 were measured using flow cytometry.Dynamic changes of C-reactive protein were also detected for each patient.Results The CD64 index and CRP levels in the bacterial pneumonia group were significantly higher than in the other three groups(P<0.05).The CD64 index in the severe bacterial infection group was significantly higher than in the mild group(P<0.05).After antibiotic treatment,expression of CD64 in the severe bacterial infection group decreased significantly(P<0.05).The CD64 index was positively correlated with CRP value(r=0.545,P<0.01).ROC curve analysis showed that the threshold of CD64 and CRP was 2.8 and 8 mg/L respectively.Specificity of CD64 index(90%) was much higher than CRP(74%).Conclusions The determination of peripheral blood neutrophil CD64 contributes to the early diagnosis of pulmonary bacterial infection and the evaluation of anti-infection effect.