Keutgens A, Monfort M, Wagemans D, Van Cauwenberge J-R, Gérard C
Laboratoire d'lmmunologie-Hématologie, Secteur Hématologie, CHU de Liège.
Rev Med Liege. 2012 Jul-Aug;67(7-8):403-6.
A Caucasian woman, with a A+ CCD.ee K neg erythrocyte phenotype and no history of blood transfusion, delivered a first child who developed mild anemia. The direct antiglobulin test performed on the newborn red blood cells belonging to the A+ CCD.ee K neg group, was strongly positive for IgG. During the pregnancy and after the delivery, the woman had a negative irregular antibody screening test, using standard red blood cells. However, at birth, using a collection of thawed red blood cells with rare phenotypes (private antigens), the lab showed an antibody anti-Wr(a) in the maternal serum. The activity of the maternal antibody, with a titer of 16, was completely inhibited by dithiothreitol, indicating the nature IgM of the circulating antibody. The presence of the antigen Wr(a) on the surface of the newborn and its biological father red blood cells was confirmed. The concentration of IgG anti-Wr(a) on baby erythrocytes was demonstrated by the presence of the antibody anti-Wr(a) in the eluate. This case illustrates the difficulties to detect antibodies against private antigens on baby erythrocytes, responsible of hemolytic diseases of newborn. Indeed, standard red blood cell panels used for irregular antibodies screening test do not express generally those private antigens.
一名具有A+ CCD.ee K阴性红细胞表型且无输血史的白种女性，产下了一名患有轻度贫血的头胎婴儿。对属于A+ CCD.ee K阴性组的新生儿红细胞进行的直接抗球蛋白试验，IgG呈强阳性。在孕期和产后，该女性使用标准红细胞进行的不规则抗体筛查试验结果均为阴性。然而，在婴儿出生时，实验室利用一组解冻的具有罕见表型（私有抗原）的红细胞，在母体血清中检测到了抗Wr(a)抗体。母体抗体活性为16，其活性被二硫苏糖醇完全抑制，表明循环抗体的性质为IgM。新生儿及其生物学父亲红细胞表面存在抗原Wr(a)得到了证实。洗脱液中存在抗Wr(a)抗体，证明了婴儿红细胞上存在IgG抗Wr(a)。该病例说明了检测新生儿红细胞上针对私有抗原的抗体（这些抗体是新生儿溶血病的病因）存在困难。实际上，用于不规则抗体筛查试验的标准红细胞谱通常不表达那些私有抗原。
