弱D25变异型血型抗原表位分析及输血策略探讨  

Epitope analysis of weak D type 25 and the transfusion strategy discussion

作　　者：王贞[1] 贾双双[1] 陈景旺 张润青[1] 罗广平[1] 姬艳丽[1] WANG Zhen;JIA Shuangshuang;CHEN Jingwang;ZHANG Runqing;LUO Guangping;JI Yanli.(Institute of Clinical Transfusion, Guangzhou Blood Center, Guang- zhou 510095, China.)

机构地区：[1]广州血液中心临床输血研究所

出　　处：《中国输血杂志》2018年第3期234-237,共4页Chinese Journal of Blood Transfusion

基　　金：广州市医药卫生科技项目(20161A011057);广州市医学重点实验室

摘　　要：目的对1例输注阳性血液的D变异型患者进行Rh血型血清学及分子生物学鉴定,并对其进行不规则抗体检测,探讨该D变异型的输血策略。方法采集患者标本,用2种不同的单克隆抗-D试剂鉴定D抗原,并用试剂盒检测D变异体抗原表位,Rh CE抗原分型,红细胞直接抗球蛋白试验,不规则抗体筛查;采用多重链接酶依赖的探针扩增（MLPA）方法检测RHD及RHCE基因型,对于MLPA检测不到的RHD突变型等位基因,对RHD基因全部10个外显子进行PCR扩增及产物直接测序分析。结果该患者初步D抗原鉴定结果显示为D抗原弱表达,且直接抗球蛋白试验阴性;D抗原表位检测结果显示其红细胞与D抗原ep D5.4、ep D2.1和ep D3.1表位特异性单克隆抗体产生弱凝集反应,与其余表位抗体均无凝集反应,大量输注D阳性血液后的168 d及232 d抗体筛查结果均为阴性;Rh CE抗原分型为cc Ee,MLPA结果显示其基因型为RHD/d,RHCE基因MLPA基因分型结果与血清学表型一致;RHD基因外显子直接测序发现其第3外显子携带纯合的c.341G〉A（p.Arg114Gln）错义突变。结论患者为弱D25变异型,对弱D25型的D抗原进行表位分析的显示其部分抗原表位缺失。该患者大量输注阳性血液后未产生抗-D,为制定该血型患者的临床输血策略提供数据。Objective A case of D variant patient with D positive blood transfusion was identified by serological and molecular tests,and unexpected antibodies monitoring was conducted to investigate the transfusion strategy of this weak D type recipient. Methods Sample was collected,two different kinds of monoclonal anti-D were used to type Rh D antigen serologically. Direct anti-globulin testing（ DAT） was conducted in microcolumn gel card. Rh D epitopes were further analyzed by using a commercial epitope detection kit（ D-Screen）. Unexpected antibodies screening was conducted in microcolumn gel card.Rh Cc Ee antigens were typed by using Rh Blood Grouping Card. The multiplex ligation-dependent probe amplification（ MLPA） assay was used to analyze the RHD and RHCE genotypes.When the MLPA was unable to identify a RHD variant,ten exons of the RHD gene were amplified by polymerase chain reaction（ PCR） and then analyzed by direct sequencing.Results The results of the preliminary D antigen identification of this patient showed that the D antigen was weakly expressed.DAT was negative. The epitope analysis of Rh D antigen by using the D-screen kit showed the red blood cells of this patient having a weak positive agglutination reaction with three monoclonal anti-D against ep D5. 4,ep D2. 1,and ep D3. 1 epitopes of D antigen,but a negative agglutination reaction with other six monoclonal anti-D. Unexpected antibodies screening results were negative on days 168 and 232 after massive transfusion of D-positive blood. The Rh CE status was cc Ee. The genotyping results of RHCE by MLPA analysis are consistent with the serological typing result.The normal D/d genotype was shown by MLPA analysis and further sequencing of all exons of the RHD gene identified a missense mutation（ c. 341〉 G A,p. Arg114 Gln） in exon3 of the RHD gene.Conclusion This patient was identified as a weak D type 25 blood type. This article for the first time analyzes the D epitopes of weak D type 25,showing some of its epitopes are missing. At the sa

关 键 词：RH血型 D变异型 弱D25型 抗原表位 

分 类 号：R457.11[医药卫生—治疗学]