毛细管血红蛋白电泳筛查新生儿中重度β地中海贫血截断值探讨

Analysis of cut-off value in screening of moderate and severe β-thalassemia by capillary hemoglobin electrophoresis for neonates

目的分析新生儿毛细管血红蛋白电泳特点,探讨筛查新生儿中重度β地中海贫血的(地贫)截断值。方法回顾性分析1 020例新生儿毛细管血红蛋白电泳结果与β地中海贫血基因检测结果。根据出生胎龄及基因结果分为6组,分析各组HbA和HbF含量。通过受试者工作曲线(ROC)确定筛查新生儿中重度β地中海贫血的截断值。结果除异常血红蛋白组外,中重度β地贫组HbA含量低于其它各组(P<0.05);中重度β地贫组HbF含量高于其它各组(P<0.001)。HbA筛查新生儿中重度β地贫曲线下面积(AUC)为0.993,大于HbF的AUC 0.697。当HbA截断值为2.35%时,灵敏度为100%,特异度为99.0%。结论毛细管血红蛋白电泳筛查新生儿中重度β地中海贫血HbA的截断值为2.35%;结合分析HbF含量及血红蛋白图谱分析可以进一步降低假阳性。

Objective To analyze the characteristics of capillary hemoglobin electrophoresis in neonates,and to determine the cut-off values of hemoglobin for moderate and severe β-thalassemia screening in neonates. Methods Retrospective analysis was performed on the results of capillary hemoglobin electrophoresis and genetic testing for 1 020 neonates.Neonates were assigned to 6 groups according to the gestational age at birth and the genetic testing results,and the HbA and HbF levels in each group were analyzed.The cut-off values for screening for moderate and severe β-thalassemia in neonates were determined using receiver operating characteristics（ROC）curve. Results HbA level was lower in moderate and severe β-thalassemia group than that in any other groups except the abnormal hemoglobin group（P〈0.05）;HbF level was higher in moderate and severe β-thalassemia group than that in any other groups（P〈0.001）.The area under curve（AUC） for HbA screening for moderate and severe β-thalassemia in neonates was 0.993,which was greater than 0.697 of HbF screening.The sensitivity and specificity of HbA cut-off values（2.35%）were 100% and 99.0%,respectively. Conclusions The cut-off value of HbA for capillary hemoglobin electrophoresis screening for moderate and severe β-thalassemia in neonates is 2.35%;Based on the cut-off value of HbA for capillary hemoglobin electrophoresis,HbF level and hemoglobin electrophoretograms could further reduce false positives.