高效液相色谱技术联合红细胞参数在血红蛋白病筛查中的应用

Application of high performance liquid chromatography(HPLC) and erythrocyte parameters in the screening of hemoglobinopathy

目的:探讨高效液相色谱(high performance liquid chromatography, HPLC)技术和红细胞参数在血红蛋白(hemoglobin, Hb)病筛查中的实际应用价值。方法:应用HPLC技术对1 029例临床疑似Hb病患者及进行溶血性贫血筛查者的血样本进行Hb分析,同时采用缺口聚合酶链反应、反向斑点杂交和珠蛋白基因DNA测序对样本进行基因分析;记录并分析患者的血常规红细胞参数。结果:1 029例血样本中,有591例(57.43%)确诊为珠蛋白生成障碍性贫血,14例(1.36%)确诊为异常Hb病。以基因分析结果为诊断金标准,应用HPLC检测β-珠蛋白生成障碍性贫血,以血红蛋白A_(2)(hemoglobin A_(2), HbA_(2))3.9%为临界值,HbA_(2)>3.9%诊断β-珠蛋白生成障碍性贫血的灵敏度为95.84%,特异度为96.87%,阳性预测值为95.40%,阴性预测值为97.20%,受试者操作特征曲线下面积(area under curve, AUC)为0.962;以HbA_(2)2.1%为临界值,HbA_(2)≤2.1%结合出现快速区带来诊断中间型α-珠蛋白生成障碍性贫血[又称血红蛋白H(hemoglobin H, HbH)病]的灵敏度为100.00%,特异度为96.32%,阳性预测值为52.60%,阴性预测值为100.00%,AUC为0.990;以HbA_(2)3.2%为临界值,HbA_(2)≤3.2%诊断静止型和标准型α-珠蛋白生成障碍性贫血的灵敏度为97.76%,特异度为53.11%,阳性预测值为24.0%,阴性预测值为99.4%,AUC为0.753。分别以平均红细胞体积(mean corpuscular volume, MCV)≤73.3 fl,平均红细胞血红蛋白量(mean corpuscular hemoglobin, MCH)≤23.5 pg,平均红细胞血红蛋白浓度(mean corpuscular hemoglobin contentration, MCHC)≤324 g/L诊断珠蛋白生成障碍性贫血,其灵敏度和特异度分别为87.98%和77.51%,93.73%和69.86%,89.20%和47.61%。结论:在红细胞参数测定的基础上,应用HPLC检测筛查β-珠蛋白生成障碍性贫血、HbH病和异常Hb病的灵敏度、特异度高,与基因分析结果间有较高的一致性,且操作简便、快速,适用于临床快速筛查;但对于静止型和标准型α-珠蛋白生成障碍性贫血,HPLC检测的筛查特异度和阳性预测值均较低,易造成漏诊。

Objective: To explore the application value of high performance liquid chromatography(HPLC) and erythrocyte parameters for screening of thalassemia in Shanghai. Methods: The hemoglobin of 1 029 samples from patients with suspected thalassemia and with suspected hemolytic anemia were analyzed using HPLC. Genetic analysis of the globin were performed simultaneously with GAP-PCR,reverse dot blot(RDB) and DNA sequencing. Results: Among 1029 samples, 591(57.43%) were diagnosed as having thalassemia and 14(1.36%) having structural hemoglobin variants.Compared with results of genetic analysis,the sensitivity,specificity,positive predictive value and negative predictive value of HbA_(2) >3.9% by HPLC as cut-off value for diagnosing β-thalassemia were 95.84%, 96.87%, 95.40%, 97.20%,with AUC of0.962. When HbA_(2)≤2.1% by HPLC as the cutoff value combined with presence of rapid band were taken for diagnosingα-thalassemia moderate(HbH disease), sensitivity, specificity, positive predictive value, negative predictive value were96.32%, 52.60%, 100.00 %, with AUC of 0.990. If f HbA_(2) ≤3.2% by HPLC was taken as the cutoff value for diagnosing minor α-thalassemia or α-thalassemia trait, the corresponding indice were 97.76%, 53.11%, 24.0%, 99.4%,and AUC was 0.753. If MCV ≤73.3 fl,MCH ≤23.5 pg,MCHC ≤324 g/L were taken as the cutoff value alone for diagnosing thalassemia, sensitivity and specificity were 87.98%,77.51%, 93.73% and 69.86%, 89.20%,47.61%,respectively. Conclusions: Based on RBC parameters analysis,results of HPLC technology have a good consistence with the resluts of gene de-tection in the diagnosis of β-thalassemia, HbH disease and structural hemoglobin variant, while a low specificity and positive predictive value may occur in the diagnosis of minor α-thalassemia orα-thalassemia trait.