缺铁性贫血对不同基因型α地中海贫血筛查的影响

Influences of iron deficiency anemia on different genetypes ofα-thalassemia screening

目的探讨缺铁性贫血对不同基因型α地中海贫血筛查的影响,评估HbA2与红细胞各指标在鉴别缺铁性贫血和各种基因型α地中海贫血中的作用。方法严格筛选正常人群样本、α地中海贫血患者样本、缺铁性贫血患者样本和α地中海贫血合并缺铁性贫血患者样本,进行血红蛋白电泳、血常规、铁蛋白和地中海贫血基因诊断,统计分析不同检测指标在各样本组差异。结果缺铁性贫血的HbA2平均水平低于α地中海贫血,HbH病患者HbA2水平低于缺铁性贫血。鉴别正常人群和单纯α地中海贫血时,MCH比MCV有更高的敏感性。鉴别α地中海贫血和缺铁性贫血时,HbA2和MCV准确度分别只有62.7%和72.4%,RDW-CV准确度为89.8%,RDW-CV在α地中海贫血合并缺铁性贫血组和单纯缺铁性贫血组之间无统计学意义。红细胞各指标在缺铁性贫血和HbH病患者的分布基本相似。结论 HbA2和红细胞指标对于鉴别α地中海贫血和缺铁性贫血的能力欠佳,特别是HbH病和缺铁性贫血很难鉴别。α基因缺失程度对HbA2和红细胞指标影响较大。α地中海贫血筛查时,铁代谢指标的检测非常重要。

Objective To investigate the influences of iron deficiency anemia on different genetypes of screening α- thalassemia and evaluate the usage of HbA2 and red blood cell parameters in differentiating α-thalassemia （including four genetypes） from iron deficiencyanemia（IDA）. Methods Normal samples, α-thalassemia samples, samples with IDA, samples with α-thalassemia combining with IDA were selected. Gene diagnosis, red blood cell analysis, ferritin and hemoglobin electrophoresis were performed for all samples. Results The HbA2 value of samples with IDA is lower than that of α-thalassemia samples. The HbA2 value of samples with HbH is lower than that of IDA samples. The sen- sitivity of MCH is higher than that of MCV when distinguishing α-thalassemia from normal pitients. The accuracy of HbA2,MCV and RDW-CV are only 62.7%, 62.7% and 89.8% respectively for distinguishing IDA from α-thalassemia. There is no statistical difference of RDW-CV between samples with α-thalassemia combining with IDA and samples with IDA. It is difficult to distingwish IDA from HbH patients because the level of red cell parameters of the two groups are similar. Different genotypes of α-thalassemia have different values of HbA2 and red blood cell parameters. Conclusion HbA2 and red blood cell parameters cannot differentiate between α-thalassemia and IDA, especially for HbH patient. The degree of α-thalassemia deletion is associated with the values of HbA2 and red blood cell parameters. Iron metabolism index detection is very important for screening α-thalassemia.