Ricci Hagman Jennifer, Westman Julia S, Hellberg Åsa, Olsson Martin L
University and Regional Laboratories, and Division of Hematology and Transfusion Medicine, Department of Laboratory Medicine, Lund University, Lund, Sweden.
Sanford Burnham Prebys Medical Discovery Institute, Center for Nanomedicine, UCSB, Santa Barbara, CA.
Immunohematology. 2018 Dec;34(4):161-163.
The main change that has occurred in the GLOB blood group system since the GLOB review published in this journal in 2013 is the addition of an antigen. The high-prevalence PX2 antigen, originally recognized as the x2 glycosphingolipid, is expressed on red blood cells of most individuals and is elevated in the rare PP1Pk-negative p blood group phenotype. P synthase, encoded by B3GALNT1, was found to elongate paragloboside to PX2 by adding the terminal β3GalNAc moiety. Hence, PX2 was moved from the GLOB collection to the GLOB system. The presence of naturally-occurring anti-PX2 was noted in P1k and P2k individuals exhibiting nonfunctional P synthase. Although the clinical significance of this specificity remains unclear, a recommendation to avoid transfusing Pk patients with p phenotype blood has been made. Currently, 13 mutations at the highly conserved B3GALNT1 locus have been found to abolish P synthase function and are recognized as null alleles by the International Society of Blood Transfusion. A new allele with a missense mutation but resulting in normal expression of P has been assigned GLOB*02. Finally, the GLOB collection was made obsolete after the move of LKE antigen to the 901 series.
自2013年本期刊发表关于GLOB血型系统的综述以来，该系统发生的主要变化是增加了一种抗原。高频率的PX2抗原最初被识别为x2糖鞘脂，在大多数个体的红细胞上表达，在罕见的PP1Pk阴性p血型表型中水平升高。由B3GALNT1编码的P合酶被发现通过添加末端β3GalNAc部分将副球蛋白延长为PX2。因此，PX2从GLOB集合转移到了GLOB系统。在表现出无功能P合酶的P1k和P2k个体中发现了天然存在的抗PX2。尽管这种特异性的临床意义仍不清楚，但已建议避免给具有p表型血液的Pk患者输血。目前，已发现高度保守的B3GALNT1基因座上的13个突变会消除P合酶功能，并被国际输血协会认定为无效等位基因。一个具有错义突变但导致P正常表达的新等位基因已被指定为GLOB*02。最后，在LKE抗原转移到901系列后，GLOB集合被淘汰。
