外周血和尿液红细胞平均体积差值在血尿定位诊断中的应用

Application of MCV cut-off value of peripheral blood and urinary erythrocytes to localization diagnosis of hematuria

目的探讨采用血、尿中红细胞平均体积差值(ΔMCV)鉴别肾性和非肾性血尿的诊断价值。方法采用BAY-120血细胞分析仪检测100例肾小球性疾病和非肾小球性疾病患者外周血和尿中ΔMCV,计算二者之间的差值,利用受试者工作曲线(ROC曲线)确定临界值;同时应用相差显微镜观察尿液异常红细胞情况。结果肾性与非肾性血尿患者自身血和尿中ΔMCV差异有统计学意义(P<0.01),ROC曲线下面积为0.978,以ΔMCV≥10fL鉴别肾性、非肾性血尿约登指数为0.82,敏感度为92%,特异性为90%。相差显微镜法的敏感度为94%,特异性为92%,两种方法诊断血尿来源差异无统计学意义(P>0.05)。结论采用血、尿中ΔMCV鉴别肾性和非肾性血尿具有较高的敏感度和特异性,可以作为筛查血尿来源较好的诊断指标。

Objective To investigate the clinical diagnosis value of detecting mean corpuscular volume（MCV） cut-off value（AMCV） for identifying the source of hematuria. Methods MCV in peripheral blood and urine erythro- cyte of 100 patients with glomerular or nongiomerular hematuria were detected by BAY-120 hematoanalyser, using receiver operating characteristic curve（ROC） to find the best cut-off value. At the same time, the urine samples were measured for abnormal RBC by phase contrast microscopy. Results AMCV was significantly different between glomerular and nonglomerular sources with statistical significance（P〈0.01）. The area under ROC curve was 0. 978. With the bounds of 10 fL, Youdent s index was 0.82, and sensitivity and specificity were 92% and 90% respectively. The sensitivity and specificity were 94% and 92% for phase contrast microscopy. There was no significant deviation between the two methods. Conclusion AMCV is a noninvasive,objective and accurate method to locate the sources of hematuria.