基因分型技术对1例PNH患者抗-C同种抗体合并抗-f类同种自身抗体的辅助鉴定

Genotyping for Auxiliary Identification of Anti-C Alloantibody with Anti-f Autoantibody Mimicking Alloantibody

目的:通过基因分型对1例有输血史的PNH患者疑难抗体进行鉴定。方法:采用卡式凝胶法检测患者RH分型,谱细胞鉴定PNH患者抗体特异性。在血清学鉴定困难的情况下,利用基因分型的方法排除RH无关表型,利用不同的RH表型细胞分别吸收放散后进行抗体鉴定,不同的RH表型细胞组合排除其它无关抗体。结果:卡式凝胶法鉴定显示RH分型C抗原存在双群,其它抗原阳性,分别进行RHD合子型鉴定、RHD和RHCE基因测序分析。结果显示,RHD基因型为纯合子RHD/RHD,RHCE基因未发现c.122A>G突变,排除携带有Cw抗原;RHCE第1外显子48G,第5外显子存在676碱基G/C杂合,第2-4、6-10外显子没有发生突变,第4内含子发现一个新的突变IVS4+29A>C。因此可以判断出RH血型基因型为Dce/DcE,其表型应该为ccDEe。结合不同的RH表型细胞吸收放散实验最终确定患者血清中含有抗-C同种抗体合并罕见的抗-f类同种自身抗体,最后选择配血相合的AB型ccDEE的红细胞输注给患者,未出现输血不良反应。结论:基因分型可以辅助用于患者血清中疑难抗体的鉴定,从而减少患者输血风险。

Objective:To identify the difficult antibody specificity of 1 PNH patient with blood transfusion history by genotyping.Methods:RH typing of this patient was performed using gel card method,the antibody specificity was identified by panel cells,the RH-unrelated phenotype were excluded by genotyping method in difficult condition of serologic identification,furthmore different RH phenotype cells were used for adsorption-elution so as to re-examine the reactivity of antibodies in this patient′s serum,and finally different RH phenotype cells were combined to exclude other unrelated antibodies.Results:The RH phenotype presented as double population for C antigen,and positive agglutination for the other antigens.The results of RHD zygote,together with RHD and RHCE sequencing showed that the RHD genotype was homozygous RHD/RHD,and the c.122 A>G mutation did not found in RHCE gene,thus Cw antigen was excluded;48 G lies in the 1 st exon,the 5 th exon showed nt676 G/C heterozygosity,the 2 nd-4 th,6 th-10 th exons did not show mutations,however a new mutation was found in the 4 th intron IVS4+29 A>C.It can be judged that the RH genotype was Dce/DcE,and its phenotype should be ccDEe.The anti-C alloantibody and rare anti-f autoantibody mimicking alloantibody in serum was determined by different RH phenotypic cell absorption-elution.Finally,crossmatched AB ccDEE blood units were selected for the patient and there was no adverse reactions of blood transfusion occurred.Conclusion:Genotyping can be auxiliarily applied to the identification of difficult antibodies in serum of a patient,thereby reducing the risk of blood transfusion.