外周血中性粒细胞CD64检测在肾移植受者肺部感染诊断中的应用价值

Applied value of peripheral neutrophile granulocyte CD64 test in the diagnosis of pulmonary infection in patients after renal transplantation

目的探讨肾移植受者外周血中性粒细胞CD64指数在移植后细菌和巨细胞病毒（CMV）感染中的应用价值。方法2007年1月至2010年7月间79例受者纳入研究，术后受者均采用以他克莫司为基础的免疫抑制方案。依据病原学诊断结果分为细菌感染组（42例）、CMV感染组（17例）以及无感染的功能稳定组（20例）。CMV感染的诊断采用间接免疫荧光方法。采用流式细胞术检测移植前后受者外周血CD64指数和T淋巴细胞绝对值，用全自动血细胞分析仪检测白细胞数量和中性粒细胞的数量。结果功能稳定组、细菌感染组和CMV感染组术前外周血白细胞、CD3’细胞和中性粒细胞绝对值的差异无统计学意义（P〉0．05）。功能稳定组术后3个月、细菌感染组和CMV感染组感染时受者外周血的白细胞、CD3’细胞和中性粒细胞绝对值的变化趋势一致，即CMV感染组绝对值均低于功能稳定组和细菌感染组，而细菌感染组高于功能稳定组，差异均有统计学意义（P〈0．01或P〈0．05）。术前以及术后1、3、7和14d时3组受者外周血中性粒细胞CD64指数的差异无统计学意义（P〉0．05）。细菌感染组感染时中性粒细胞CD64指数为4．087±1．485，与功能稳定组术后3个月时的1．031±0．412相比较，差异有统计学意义（P〈0．05）；细菌感染组与CMV感染组感染时的1．694±0．801相比较，差异也有统计学意义（P〈0．01）；CMV感染组感染时与功能稳定组术后3个月相比较，差异无统计学意义（P〉0．05）。CD64指数预测细菌感染的最适cutoff值为1．51，其敏感性为95．3％，特异性为86．5％，曲线下面积（AUC）为0．91。CD64指数预测CMV感染的最适cutoff值为1．48，其敏感性为52．9％，特异性为90．0％，AUC为0．76。结论CD64指数可以作为诊断肾移植受者细菌感染的参考指标，具有较高的敏感性、特异性及准确性。

Objective To evaluate the early diagnostic value of CD64 index for bacterial infection and cytomegalovirus （CMV） infection in patients following renal transplantation. Method Seventy-nine recipients who underwent renal allograft transplantation between March 2010 and February 2011 were enrolled in the study. All patients received maintenance irnmunosuppressive therapy protocol based on tacrolimus. All patients were classified into three groups according to etiology： simple bacterial infection group （n = 42）, simple active CMV infection group （n = 17）, and stable function group （n = 20）. CD64 index and absolute T cells count were analyzed by using flow cytometry. White blood cells （WBC） and neutrophils were measured by using automated hematology analyzer. CMV infection was diagnosed by indirect irrmaunofluoreseenee method. Results The absolute counts of WBC, CD3and PMN showed no significant difference among stable function group, bacterial infection group and CMV infection group （P = 0. 32,0. 77 and 0. 98, respectively） before transplantation. The WBC counts in bacterial infection group and active CMV infection groupwere significantly different from those in stable function group （P〈0. 001）. The WBC counts in active CMV infection group was significantly less than those in bacterial infection group and stable function group, and those in bacterial infection group were significantly more than those in stable function group. The CD3＋ counts in bacterial infection group and active CMV infection group were significantly different from stable function group （P = 0.019）. The CD3＋ counts in active CMV infection group were significantly less than those in bacterial infection group and stable function group, and those in bacterial infection group were significantly more than those in stable function group. The PMN counts in bacterial infection group and active CMV infection group were significantly different from control group （P〈0. 00l）. The PMN counts in active CMV infection group were significantly less than those in bacterial infection group and stable function group, and those in bacterial infection group were significantly more than those in stable function group. The levels of neutrophil surface CD64 had no significant difference among active CMV infection group, bacterial infection group and stable function group （P〈0. 05） before transplantation. However, the levels of neutrophil surface CD64 in bacterial infection group （4. 087 ± l. 485 ） were significantly higher than those in stable function group （ 1. 031 ± 0. 412） after transplantation, there was statistically significant difference between bacterial infection group and active CMV infection group （1. 694 ±0. 801） （P〈0. 001 ）, and there was no statistically significant difference between acute CMV infection group and stable function group （P〈0. 05）. The best cutoff value of CD64 index to predict bacterial infection was 1.51, and the sensitivity, specificity and AUC were 95.3%,86. 5% and 0. 91 respectively. The best cutoff value of CD64 index to predict active CMV infection was 1.48, and the sensitivity, specificity and AUC were 52.94%,90.0% and 0.76 respectively. Conehtsion CD64 index is of great value for the early diagnosis of bacterial infection and CMV infection in patients after transplantation, and has higher sensitivity, specificity and accuracy.