Pathology & Laboratory Medicine, O'Connor Hospital/A Community Hospital of County of Santa Clara Heath System, San Jose, California.
Pediatrix Medical Group of San Jose, California.
Transfusion. 2020 Apr;60(4):870-874. doi: 10.1111/trf.15709. Epub 2020 Feb 14.
The clinical and laboratory features of hemolytic disease of the newborn can be challenging to diagnose during pregnancy in the apparent absence of a blood group antibody. Low-frequency antibodies go undetected due to the lack of appropriate antigen-positive reagent red blood cells (RBCs).
A pregnant woman of Southeast Asian descent was referred to a maternal-fetal medicine outpatient clinic due to a complicated obstetric history and a negative antibody screen. This initial visit at 29 weeks and 0 days' gestational age (GA) was unremarkable. A hydropic infant, born at 29 weeks and 5 days' GA, succumbed on the seventh day of life. Comprehensive laboratory testing was performed after birth. The hospital blood bank performed a maternal antibody identification. Direct antiglobulin test was performed on the cord blood. A reference laboratory confirmed an anti-Mi , performed paternal Mi phenotyping, and identified a hybrid glycophorin B-A-B GP*Mur allele.
Maternal alloimmunization to low-frequency antigens remains a challenge. Southeast Asians make up a significant percentage in some US locations. Worldwide reports on the frequency of maternal alloimmunization of the MNS system can be used to guide the use of specific reagent RBCs for testing. Such strategies rely on the identification of blood donor units for reagent manufacture and use in perinatal antibody screens.
The incidence of Mi and related antibodies is significant among Southeast Asians. In North America, prenatal antibody screening cells are not routinely chosen to match this population. The clinical and societal implications are discussed.
在妊娠期间，在明显缺乏血型抗体的情况下，新生儿溶血病的临床和实验室特征可能难以诊断。由于缺乏适当的抗原阳性试剂红细胞（RBC），低频抗体未被检测到。
一名东南亚裔孕妇因复杂的产科病史和抗体筛查阴性而被转至母体胎儿医学门诊。初次就诊时孕周为 29 周零 0 天，无明显异常。一名水肿婴儿于 29 周零 5 天胎龄（GA）出生，出生后第 7 天死亡。出生后进行了全面的实验室检查。医院血库进行了母亲抗体鉴定。对脐血进行直接抗球蛋白试验。参考实验室确认了抗-Mi，并进行了父亲 Mi 表型分析，鉴定出混合糖蛋白 B-A-B GP*Mur 等位基因。
低频抗原的母体同种免疫仍然是一个挑战。在一些美国地区，东南亚人占很大比例。全球关于 MNS 系统母体同种免疫频率的报告可用于指导用于检测的特定试剂 RBC 的使用。这些策略依赖于为试剂制造和用于围产期抗体筛查选择供者单位。
在东南亚人群中，Mi 和相关抗体的发生率很高。在北美，产前抗体筛查细胞通常不选择与该人群匹配。讨论了临床和社会影响。
