天然ABO抗体缺失的分子机制研究

Molecular mechanisms of natural ABO antibodies deficiency

目的 从ABO基因水平探讨正常人群血型鉴定中出现天然抗体缺失的机制.方法 部分或全部缺失抗体导致ABO血型正反定型不一致的15个正常健康个体运用检验红细胞表面血型抗原最为敏感的方法-吸收放散试验未能检测出其抗原性.PCR扩增后直接序列分析ABO基因全长编码区及5＇端调控（CBF/NF-Y）增强子区域多态性.结果 在常规的血清学反向定型实验中,这15个标本的血清中部分或全部缺失抗体,吸收放散实验与A或B型红细胞反应均为阴性.12个标本的ABO基因分析定型、增强子区域多态性与血清学结果相符合,1个O表型的标本中存在B101等位基因,2个B表型标本中检测出A102等位基因.结论 天然ABO抗体缺失的分子机制可能部分被揭示：ABO基因编码少量表达抗原,按照天然抗体产生规律,导致不能产生相应的ABO抗体.ABO基因分型在正反定型不符的疑难血液标本鉴定中,是血清学方法 非常有益的补充手段,是正确鉴定血型的有效方法.

Objective To investigate the mechanism of natural ABO antibodies deficiency in ABO blood group of common population. Methods Fifteen common healthy individuals with ABO inconsistency in forward and reverse typing caused by partly or entirely lacking antibodies were accessed by adsorptionelution test. DNA analysis on whole code sequences of ABO gene and the polymorphisms of CBF/NF-Y enhancer region were preformed in these individuals. Results In routine ABO grouping, 15 blood samples were shown to be entirely or partly deficient of natural antibodies. Adsorption-elution tests performed by testing A or B RBC were all negative. Sequences of ABC code gene and polymorphisms of the enhance region from 12 samples were consistent with the ABO forward type. Interesting, one sample typed O phenotype was characterized as heterozygous B101/O02, and A102 allele was demonstrable in two cases with B phenotype. Conclusion The molecular mechanisms in deficiency of natural ABO antibody could be clarified partly. ABH antigens are expressed little on red cell membranes, so that relevant antibodies are not formed.ABO genotyping technique is a good method for blood bank service and a complement method for determination of donor blood status by seroloty.