多次输血尿毒症患者免疫抗-Jk3引起输血无效及家系分子生物学研究

Molecular pedigree analysis for Allo-immunization induce anti-Jk3 in a uremic patient with multiple transfusion

目的:对罕见Jknull血型患者产生抗-Jk3引起的输血无效进行表型分子机理分析及家系调查与输血史调查。方法:对先证者血样进行直接抗人球蛋白实验、血清游离抗体和红细胞放散试验;对其家系进行Kidd标清定型与分子生物学分析。Kidd血型系统Jka与Jkb抗原决定位采用荧光染料结合PCR-SSP技术进行分析,并对调控Kidd血型系统的SLC14A1基因进行全基因片段扩增与Sanger直接测序分析碱基变异。结果:先证者抗体鉴定结果为抗-Jk3,标清定型为Jk(a-b-),基因分型为Jk(a-b+);先证者子代与丈夫的标清定型与基因分型皆为Jk(a-b+)。SLC14A1基因测序与家系调查结果,先证者两等位基因分别是(341+12C>T,342-1G>A,588A>G,838G>A)和(222C>A,499A>G,588A>G,838G>A)。先证者子代携带等位基因(341+12C>T,342-1G>A,588A>G,838G>A)但表型正常。先证者为尿毒症患者,输血前检测从抗筛试验阴性与直抗试验阳性,转为抗筛与直抗试验皆为阳性,直抗阳性样本进行放散试验结果为抗-Jk3。结论:先证者两条等位基因中出现342-1G>A与222C>A导致SLC14A1基因产物抗原性消失而出现Jknull血型,对长期需要多次输血患者应进行直抗试验追踪或于疾病初期应进行稀有血型抗原检测,避免高频抗原抗体免疫。

Objective:To analyze the molecular pedigree of a patient with Jknull phenotype and to review the blood transfusion records of the proband.Methods:The direct anti-human-globulin test,serum free anti body and erythrocyte dispersion tests were determined with a conventional method.Kidd serotyping and molecular biology analysis were carried out in the family.The antigenic localization of Jka and Jkb was analyzed by fluorescent dye combined with PCR-SSP,and SLA14A1 gene was amplified and sequenced by Sanger.Results:The phenotype was Jknull in the proband with recent multiple allogenic transfusion record,in contrast to the genotype was Jk(a-b+)and antibody identification demonstrated anti-Jk3.The phenotype of proband's husband and son was Jk(a-b+)same as genotype.The molecular pedigree analysis demonstrated the alleles of proband were 341+12C>T,342-1G>A,588 A>G,838 G>A,and another were 222C>A,499A>G,588A>G,838G>A.The proband′s off spring carried alleles(341+12C>T,342-1G>A,588A>G,838G>A),but the phenotype was normal.The test results of the proband before blood transfusion changed from negative anti screening test and positive direct antibody test to positive anti screening test and positive direct antibody test.The elution suspension identified as anti-Jk3.Conclusion:The SNPs of 341+12C>T and 222C>A cause frame variant of SLC14A1 gene and induce to Jknull phenotype.To avoid allo-immunization to produce antibodies react to high frequency antigen,patients who expectedly need to receive multiple transfusion in a long term may follow up the direct coombs test or rare blood group antigen should be detected at the early stage.