血红蛋白双重杂合子对不同糖化血红蛋白检测系统结果的影响

目的观察Hb Q-H和Hb J-Bangkok合并β地中海贫血(简称"地贫")双重杂合子患者糖化血红蛋白A1c(HbA1c)对不同糖化血红蛋白检测系统结果的影响。方法收集20例表观健康成年人和20例2型糖尿病(T2DM)患者标本,用于5个糖化血红蛋白检测系统间的结果比对。收集1例Hb Q-H患者标本和1例Hb J-Bangkok合并β地贫双重杂合子患者标本,用Capillarys2行血红蛋白毛细管电泳,用gap-PCR、PCR-RDB和基因测序方法鉴定2例异常标本的珠蛋白基因。同时用BioRad VARIANTⅡ(VⅡ)、BioRad VARIANTⅡTurbo2.0(VⅡ-T2.0)、Capillarys 2 Flex Piercing(C2FP)、Primus Ultra2(Ultra2)、Roche PPI 800(PPI 800)5个糖化血红蛋白检测系统检测所有标本的HbA1c结果,其中对于双重杂合子标本,每个检测系统检测3次,保存图谱和检测结果并对比分析。结果 Hb Q-H标本的基因型为--α^QT/--SEA;β~N/β~N,珠蛋白α1链发生HbA1 CD74G>C突变,形成Hb Q-Thailand血红蛋白变异体,无正常的α珠蛋白肽链。Hb J-Bangkok合并β地贫的基因型为:αα/αα;β^CD56/β^CD41-42,珠蛋白β链第56位密码子发生GGC>GAC点突变,形成Hb J-Bangkok血红蛋白变异体,无正常的β珠蛋白肽链。对于Hb Q-H标本,5个HbA1c检测系统中有3个检测系统报告了HbA1c结果;VⅡ和VⅡ-T2.0系统图谱与正常图谱存在明显区别,未报告HbA1c结果;C2FP系统图谱与正常图谱相似,HbA1c结果为3.7%;Ultra2系统和PPI系统报告了HbA1c结果,分别为5.3%和5.7%,不存在异常提示。对于Hb J-Bangkok合并β地贫标本,5个HbA1c检测系统中有3个检测系统报告了HbA1c结果;VⅡ系统图谱与正常图谱存在明显区别,未报告HbA1c结果;VⅡ-T2.0系统图谱与正常图谱存在区别,存在84.9%的P4峰,报告了HbA1c结果为4.7%;C2FP系统图谱与正常图谱存在明显区别,未报告HbA1c结果。Ultra2系统和PPI系统均报告了HbA1c结果,分别为4.7%和3.8%,不存在异常提示。结论 Hb Q-H患者与Hb J-Bangkok合并β地贫患者标本均不含正常的HbA,应无HbA1c结果。对于二者,VⅡ系统及VⅡ-T2.0系统的结果图谱存在明显异常,提示结果不可报告;Hb Q-H对C2FP系统存在明显干扰,报告了HbA1c结果,而Hb J-Bangkok合并β地贫标本C2FP系统未报告HbA1c结果;二者对PPI及Ultra2系统存在明显干扰。

Effect of double heterozygous hemoglobin on the results of different glycosylated hemoglobin detection systems

Objective To investigate the effects of glycosylated hemoglobin A1c (HbA1c) from the patients with double heterozygotes Hb Q-H and Hb J-Bangkok combined with β-thalassemia on the results of different HbA1c detection systems. Methods Blood samples from 20 healthy adults and 20 patients with type 2 diabetes mellitus (T2DM) were collected to assess the results of five glycosylated hemoglobin detection systems. Blood samples from one Hb Q-H patient and one Hb J-Bangkok patient with β-thalassemia were also collected, and they were performed hemoglobin capillary electrophoresis with Capillarys2 and globin gene analysis by gap-PCR, PCR-RDB and DNA sequencing. The levels of HbA1c in all samples were detected by BioRad VARIANT Ⅱ(VⅡ), BioRad VARIANT ⅡTurbo2.0 (V Ⅱ-T2.0), Capillarys 2 Flex Piercing (C2FP), Primus Ultra2 (Ultra2) and Roche PPI 800 (PPI 800) glycosy lated hemoglobin detection instruments, respectively. For the samples with double heterozygotes, the levels of HbA1c were detected for 3 times each sample, and the results were preserved and analyzed. Results The genotype of the Hb Q-H sample was --α^QT /--SEA;β^N/β^N, and HbA1 CD74 G>C mutation occurred in globin α1 chain, forming Hb Q-Thailand hemoglobin variant without normal α-globin peptide chain. The genotype of Hb J-Bangkok combined with β-thalassemia was αα/αα;β^CD56 /β^CD41-42 , and the point mutation of GGC>GAC occurred at codon 56 of globin β-chain, forming Hb J-Bangkok hemoglobin variant without normal β-globin peptide chain. For the Hb Q-H sample, HbA1c results were reported by 3 of 5 HbA1c detection systems. The chromatograms of VⅡ and VⅡ-T2.0 detection systems were obviously different from normal chromatograms, and HbA1c results were not reported. However, the chromatograms of the C2FP system were similar to normal chromatograms, and the result of HbA1c was 3.7%. The Ultra2 system and PPI system reported the HbA1c results, 5.3% and 5.7%, respectively, without abnormal alarm. For the Hb J-Bangkok with β-thalassemia sample, HbA1c results were also reported by 3 of 5 HbA1c detection systems. The chromatograms of VⅡ and Sebia detection systems were obviously different from normal chromatograms, and HbA1c results were not reported. However, the chromatograms of VⅡ-T2.0 system were different from normal chromatograms, and a P4 peak (84.9%) was found. The HbA1c result was reported as 4.7%. The Ultra2 system and PPI system reported the HbA1c results, 4.7% and 3.8%, respectively, without abnormal alarm. Conclusion The samples from the Hb Q-H patient and the Hb J-Bangkok patient with β-thalassemia do not contain normal HbA, and there should be no HbA1c results. The chromatograms of VⅡ and VⅡ-T systems are obviously abnormal, indicating that the results can not be reported. The C2FP system is interfered obviously by Hb Q-H, but reports the HbA1c results, while it does not report the HbA1c results of Hb J-Bangkok combined with β-thalassemia. Both of Hb Q-H and Hb J-Bangkok have obvious interference to PPI and Ultra2 detection systems.