Grueger Daniela, Zeretzke Anja, Habicht Cora P, Skaik Younis, Wagner Franz F, Scharberg Erwin A, Costelloe Aisling, Martens Jörg, Verboom Murielle, Bugert Peter, Schneeweiss Clemens
Imusyn GmbH & Co. KG, Hanover, Germany.
Institute of Transfusion Medicine and Transplant Engineering, Hannover Medical School, Hanover, Germany.
Transfusion. 2020 Oct;60(10):2408-2418. doi: 10.1111/trf.16039. Epub 2020 Sep 1.
All antigens described in the KN blood group system are located in the long homologous repeat D (LHR-D) of complement receptor 1 (CR1). While there have been reports that some sera react only with the long homologous repeat C (LHR-C), the antigens in LHR-C are unknown.
Recombinant LHR-C and LHR-D were used to identify antibodies directed against LHR-C of CR1, into which a point mutation was introduced to characterize the underlying blood group antigens. In addition, database studies to define haplotypes of CR1 were performed.
Several antisera were identified that were specific against CR1 p.1208His and against CR1 p.1208Arg, located in LHR-C. Fifteen KN haplotypes were found in the Ensembl genome browser. It was shown that due to a linkage disequilibrium anti-CR1 p.1208His may be mistaken for anti-KCAM.
A novel antithetical KN blood group antigen pair was found at position p.1208 of CR1, for which the names DACY and YCAD are proposed. Antibodies against these two novel antigens seem to contribute to more than a quarter of all KN sera in Europe.
KN血型系统中描述的所有抗原都位于补体受体1（CR1）的长同源重复序列D（LHR-D）中。虽然有报道称一些血清仅与长同源重复序列C（LHR-C）发生反应，但LHR-C中的抗原尚不清楚。
使用重组LHR-C和LHR-D来鉴定针对CR1的LHR-C的抗体，并引入点突变以表征潜在的血型抗原。此外，还进行了数据库研究以定义CR1的单倍型。
鉴定出几种针对位于LHR-C中的CR1 p.1208His和CR1 p.1208Arg的特异性抗血清。在Ensembl基因组浏览器中发现了15种KN单倍型。结果表明，由于连锁不平衡，抗CR1 p.1208His可能被误认为是抗KCAM。
在CR1的p.1208位置发现了一对新的KN血型抗原对偶，建议将其命名为DACY和YCAD。针对这两种新抗原的抗体似乎占欧洲所有KN血清的四分之一以上。
