Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen, Thailand.
Centre for Research and Development of Medical Diagnostic Laboratories, Faculty of Associated Medical Sciences, Khon Kaen University, Khon Kaen 40002, Thailand, Phone/Fax: +66-43-202-083.
Clin Chem Lab Med. 2018 Aug 28;56(9):1507-1513. doi: 10.1515/cclm-2018-0089.
The objective of the study was to describe a formula based on hemoglobin (Hb)A2 and HbF levels for differentiation of homozygous HbE and HbE-β-thalassemia.
A total of 1256 subjects suspected for homozygous HbE or HbE-β0-thalassemia were recruited at the ongoing thalassemia screening program at Khon Kaen University, Thailand. Hb analysis was done using capillary electrophoresis. Genotyping was based on DNA analysis. An arbitrary formula based on HbA2 and HbF was developed statistically for differentiation of the two conditions. Validation was carried out prospectively on another 139 subjects encountered at routine laboratory.
Among 1256 subjects, Hb and DNA analyses identified cases with homozygous HbE (n=1076, 85.7%), HbE-β0-thalassemia (n=140, 11.1%), HbE-δβ0-thalassemia (n=30, 2.4%) and unknown HbE-related disorder (n=10, 0.8%). An inverse correlation between the amounts of HbA2 and HbF in HbE-β0-thalassemia was observed. With differences in the amounts of HbA2 and HbF between the groups, an arbitrary score (7.3 HbA2+HbF) was developed where score above 60 indicated HbE-β0-thalassemia. Application of this score on another 139 subjects showed accurate prediction of HbE-β0-thalassemia with 100% sensitivity, 96.5% specificity, 85.7% positive predictive value and 100% negative predictive value. Successful application onto couples at risk was demonstrated.
An established score should prove useful in the differentiation of homozygous HbE and HbE-β0-thalassemia in routine setting and lead to a significant reduction in number of referring cases for molecular testing.
本研究的目的是描述一种基于血红蛋白（Hb）A2 和 HbF 水平的公式，用于区分纯合 HbE 和 HbE-β 地贫。
在泰国孔敬大学正在进行的地贫筛查项目中，共招募了 1256 名疑似纯合 HbE 或 HbE-β0 地贫的受试者。使用毛细管电泳法进行 Hb 分析。基于 DNA 分析进行基因分型。基于统计学方法开发了一种基于 HbA2 和 HbF 的任意公式，用于区分两种情况。在常规实验室遇到的另外 139 名受试者中进行了前瞻性验证。
在 1256 名受试者中，Hb 和 DNA 分析鉴定出纯合 HbE（n=1076，85.7%）、HbE-β0 地贫（n=140，11.1%）、HbE-δβ0 地贫（n=30，2.4%）和未知的 HbE 相关疾病（n=10，0.8%）。在 HbE-β0 地贫中观察到 HbA2 和 HbF 量之间的反比关系。由于各组 HbA2 和 HbF 量的差异，开发了一个任意评分（7.3 HbA2+HbF），其中评分高于 60 表示 HbE-β0 地贫。将该评分应用于另外 139 名受试者，显示出对 HbE-β0 地贫的准确预测，敏感性为 100%，特异性为 96.5%，阳性预测值为 85.7%，阴性预测值为 100%。成功应用于高危夫妇。
该既定评分应有助于在常规环境中区分纯合 HbE 和 HbE-β0 地贫，并显著减少需要进行分子检测的转诊病例数量。
