ROC曲线分析血红蛋白A2筛查地中海贫血的价值

Value of Analyzing Hemoglobin A_2 by ROC Curve for Screening Thalassemia

目的:探讨血红蛋白A2(HbA_2)指标在地中海贫血筛查中的诊断价值。方法:收集2013年6月到2014年1月来本院就诊的成人外周血2 000例。应用全自动毛细管血红蛋白电泳分析HbA_2含量,同时检测地中海贫血基因。通过受试者工作曲线(ROC曲线)确定HbA_2在不同类型的地中海贫血中的最佳截断值。结果:HbA_2指标在诊断静止型,轻型,中间型α-地中海贫血和轻型β-地中海贫血的最佳截断值分别为2.85%、2.65%、2.25%和3.45%;ROC曲线下面积分别为0.709、0.839、0.979和0.997;敏感度分别为0.481、0.721、0.953和0.994;特异性分别为0.846、0.837、0.929和0.969。结论:利用ROC曲线建立了本实验室诊断不同类型地中海贫血HbA_2的最佳截断值。ROC曲线下面积可以表明HbA_2指标对诊断中间型α-地中海贫血和轻型β-地中海贫血具有较高准确性。

Objective：To investigate the value of hemoglobin A2（HbA2） for screening thalassemia.Methods：A total of 2 000 adults＇ peripheral blood samples from Guangdong Women and Children Hospital from June 2013 to January2014 were collected.The hemoglobin A2（HbA2） level was analyzed by the full automatic capillary electrophoresis technique,and the genotypes of thalassemia were detected.Results：The optimal cutoff values of HbA2 for screening silent a-thalassemia,a-thalassemia trait,intermedia a-thalassemia and β-thalassemia trait were 2.85%,2.65%,2.25%and 3.45%,respectively;the areas under receiver operator characteristic（ROC） curve were 0.709,0.839,0.979 and 0.997 respectively;the sensitivities were 0.481,0.721,0.953 and 0.994,and the specificities were 0.846,0.837,0.929 and 0.969 respectively.Conclusion：The optimal cutoff values of HbA2 for screening different type of thalassemia based on our laboratory data are established by using ROC curve.According to the area under ROC curve,a satisfactory accuracy for screening intermedia a-thalassemia and β-thalassemia trait can be achieved by detecting hemoglobin A2 level.