ABO变异型B305亚型的血清学特点及基因序列分析

Serological characteristics and gene sequence analysis of ABO variant B305 subtype

目的:探讨分析ABO血型变异型B305亚型的血清学特点及基因序列,为后续输血奠定策略。方法:采用盐水试管凝集法进行ABO血型正反定型,采用聚合酶链反应直接测序技术(PCR-SBT)进行B抗原基因分型,采用Sanger测序法进行B抗原基因测序,采用盐水法和凝聚胺法进行交叉配血。结果:3例先证者红细胞上含有弱B抗原,血清中存在抗-A抗体;等位基因结果为ABO*B3.05,与标准序列比较其c.425 T>C发生突变,引起其多肽链P.Met142Thr的氨基酸替换。与B型、O型红细胞交叉配血无凝集无溶血反应。结论:ABO血型第7外显子c.425 T>C突变是导致B305亚型抗原弱表达的分子机制,基因测序结合亚型血清学特点对其后续输血策略具有重要意义。

Objective: To explore and analyze the serological characteristics and gene sequence of the ABO variant B305 subtype and propose strategies for subsequent blood transfusions. Methods: ABO blood group typing was performed using the saline test tube agglutination method. B antigen genotyping was conducted using the PCR-SBT method, and B antigen gene sequencing was carried out using the Sanger sequencing method. Cross-matching was performed using the polybrene method. Results: Three probands exhibited weak B antigens on their red blood cells and had anti-A antibodies in their serum. The allele result was identified as ABO*B3.05, and a c.425 T>C mutation was detected compared to the standard sequence. This mutation resulted in the substitution of amino acid P.Met142Thr in the polypeptide chain. Cross-matching experiments with type A red blood cells displayed agglutination reactions, while no agglutination or hemolysis reactions were observed with type B and type O red blood cells. Conclusion: The weak expression of the B305 subtype antigen may be attributed to the ABO blood group exon 7 c.425 T>C mutation. These findings hold significant implications for the study of subsequent blood transfusion strategies.