1例部分D表型献血者RhD抗原表位及分子机制研究  

Study on the Rhesus D Antigen Epitopes and Molecular Mechanism of One Blood Donor with Partial D

作　　者：李明浩 杨佳璇 李艾静 朱自严[1] 叶璐夷[1] LI Ming-hao;YANG Jia-xuan;LI Ai-jing(Shanghai Blood Center,Shanghai 200051)

机构地区：[1]上海市血液中心,上海市输血研究所,分子免疫血液学学科课题组,200051

出　　处：《临床输血与检验》2022年第1期16-21,共6页Journal of Clinical Transfusion and Laboratory Medicine

基　　金：上海市卫生健康委员会面上项目(No.201940442);上海市卫生健康委员会课题(No.2021HP40)资助。

摘　　要：目的研究1例RhD抗原表型为部分D的献血者RhD抗原和分子机制。方法利用血清学方法对1例初筛为RhD阴性样本进行RhD阴性确认并进行CE分型;采用D-screen检测该样本RhD抗原表位。利用Sanger测序法对RHD基因的全部外显子测序。建立数字PCR鉴定RHD基因型的方法并分析该例样本RHD基因合子型。采用Robetta同源建模方法比较该例样本与野生型RhD蛋白的构象。结果经血清学鉴定为部分D表型,CE分型为CcEe。基因测序发现,RHD基因4号外显子存在c.492C>G突变。数字PCR鉴定该例样本的RHD基因型为D+/D–。同源建模结果提示天冬氨酸被谷氨酸替换影响RhD蛋白第3个胞外环的构象。结论RHD*492G导致部分抗原表位缺失,表现为部分D表型,属于国内首次报道。数字PCR技术用于RHD基因合子型检测,相比于实时定量PCR技术重复性和准确性均有改进。Objective To study the RhD epitope pattern and molecular mechanism of a volunteer blood donor whose phenotype is partial D.Methods Serological methods were used for weak D test and CE phenotyping for one blood sample which was identified as D-negative initially;and D-screen kit was used to analyze RhD epitopes.All exons of RHD were sequenced by Sanger sequencing method.We developed a method to determine RHD zygosity based on droplet digital PCR and analyzed the sample.Robetta modeling was used to compare the conformations of RhD protein between wild type and the sample.Results It was identified as partial D phenotype serologically,and the CE type was CcEe.The c.492C>G base change of exon 4 of RHD gene was identified by sequencing.The results of ddPCR showed that RHD genotype of the sample was D+/D–.Aspartic acid replaced by glutamic acid may influence the conformation of the third extracellular loop of RhD protein according to Robetta modeling results.Conclusion This is the first domestic report of the variant allele RHD*492G,which results in partial D phenotype with lack of some D epitopes.Compared with RT-PCR,the ddPCR method showed better repeatability and accuracy when used for determining RHD zygosity.

关 键 词：RHD抗原 部分D表型 数字PCR 同源建模 

分 类 号：R457.11[医药卫生—治疗学]