罕见AB型类孟买血型的鉴定

Identification of Rare AB Para-Bombay Phenotype

目的:通过对3例罕见AB型类孟买血型的鉴定,研究类孟买血型的血清学特征以及分子机制。方法:用单克隆抗-A、抗-B、抗-H试剂以及A、B、O标准红细胞对样本进行血型鉴定,吸收放散试验检测红细胞上弱表达的ABO抗原,检测唾液中ABH物质,测定血浆A、B糖基转移酶活性,筛查血浆中不规则抗体。应用序列特异性引物聚合酶链反应(PCR-SSP)技术进行ABO基因分型,并扩增FUT1编码区序列后对PCR产物进行直接测序分析。结果:3例患者血清学鉴定均为ABm h,血浆中存在37℃无活性的抗-H(I)。ABO基因分型结果为AB型,FUT1基因测序结果显示患者1和患者3存在551~552位AG两碱基的纯合缺失(h1h1型),患者2存在551~552位AG两碱基和881~882位TT两碱基的杂合缺失(h1h2型)。结论:联合运用血清学和分子生物学方法可准确鉴定类孟买血型。

Objective:The serological characteristics and molecular mechanism of para-Bombay phenotype were studied through the identification of 3 rare cases of ABm h phenotype.Methods:Blood group identification was carried out using monoclonal antibody-A,antibody-B,antibody-H and A,B,O standard erythrocytes.ABO antigens weakly expressed on red blood cells were detected by adsorption-elution tests.ABH substance in saliva was detected.The activities of A and B glycosyltransferase in plasma were measured.The irregular antibodies in plasma were screened.ABO genotyping was performed by polymerase chain reaction with sequence specific primers(PCR-SSP),and the coding region of FUT1 gene was amplified for direct sequencing analysis of PCR products.Results:3 patients were identified as ABm h by blood group serological method,and there was inactive anti-H(I)at 37℃in the plasma.The ABO genotype of them were AB.FUT1 gene sequencing results showed that patients 1 and 3 had two bases deletions at 551~552(AGAGAG→AGAG)(h1h1),and patient 2 had one was two bases deletions at 551~552(AGAGAG→AGAG)and another one was two bases deletions at 881~882(TTT→T)(h1h2).Conclusion:Combined serological and molecular biological methods can accurately identify Para-Bombay phenotypes.