全自动毛细管电泳仪筛查珠蛋白生成障碍性贫血应用研究

Application of automatic capillary electrophoresis in screening of thalassemia in Chengdu region

目的了解成都地区珠蛋白生成障碍性贫血(又称地中海贫血,简称地贫)患者的基因型,探讨全自动毛细管电泳仪在地贫筛查中的应用价值。方法以3 262例接受健康体检的成人为研究对象,以血常规检查进行初筛。对初筛阳性者和150例健康者进行血红蛋白(Hb)毛细管电泳检测。以基因检测结果确定地贫患者基因型。以基因检测结果为参比标准,计算毛细管电泳法检测在HbA2取不同截断值时对地贫的诊断效能。以受试者工作特征曲线(ROC曲线)确定最佳截断值。结果 3 262例体检者中,基因检测确诊地贫患者111例(3.40%),其中α地贫检出率为2.21%,β地贫检出率为1.19%,主要的基因型为--SEA/αα。以基因检测结果为参比标准,以试剂盒提供的HbA2参考区间作为诊断标准,则电泳法诊断β地贫的灵敏度、特异度、准确度、阳性预测值和阴性预测值最高分别为100.00%、98.00%、92.86%、100.00%、98.41%,诊断α地贫分别为29.17%、97.33%、84.00%、74.11%、75.23%。在ROC曲线中,当截断值为HbA2≤2.5%时,诊断α地贫的灵敏度和特异度达到最佳值分别为48.61%、62.00%;当截断值未HbA2≥3.5%时,诊断β地贫的灵敏度和特异度则达到100.00%、99.33%。结论成都地区为地贫低发病率区域。全自动毛细管电泳仪可用于β地贫常规筛查,但对α地贫的筛查诊断效能较低。

Objective To investigate the genotypes of thalassemia in Chengdu and to explore the application value of automatic capillary electrophoresis in the screening of thalassemia .Methods Blood routine examination was performed in 3 262 subjects ,re-ceiving healthy examination ,for preliminary screening .Hemoglobin（Hb） was detected in subjects with positive result of preliminary screening and 150 cases of healthy subjects by using capillary electrophoresis .The sensitivity（Se） ,specificity（Sp） ,accuracy（Ac） , positive predictive value（PPV） and negative predictive value（NPV ） of HbA2 detection in the diagnosis of thalassemia were esti-mated by using receiver operating characteristic（ROC） curve .Results Among the 3 262 subjects ,receiving health examination ,111 （3 .40% ） cases were diagnosed with thalassemia .The detection rates of α-thalassemia and β-thalassemia were 2 .21% and 1 .19% , with the main genotype of --SEA /αα .When taking genetic test results as reference standard and the laboratory reference of HbA2 as cut-off value ,the diagnostic Se ,Sp ,Ac ,PPV and NPV of electrophoresis for β-thalassemia were the highest ,which were 100 .00% ,98 .00% ,92 .86% ,100 .00% and 98 .41% ,and those for α-thalassemia were 29 .17% ,97 .33% ,84 .00% ,74 .11% and 75 .23% .In the ROC curve ,when the cut-off value of HbA2 was less than or equal to 2 .5% ,the diagnostic Se and Sp for α-thalas-semia achieve the best value（48 .61% and 62 .00% ） ,and when the cut-off value was greater than or equal to 3 .5% ,the diagnostic Se and Sp for β-thalassemia reached 100 .00% and 99 .33% .Conclusion Chengdu region could be a low incidence area of thalasse-mia .Automatic capillary electrophoresis could be used for the routine screening of β-thalassemia ,but with low diagnostic valve for the screening of α-thalassemia .