Laboratory Manager, National Molecular Laboratory, American Red Cross Biomedical Services.
Consultant, Technical Trainer, National Molecular Laboratory, American Red Cross Biomedical Services, Philadelphia, PA.
Immunohematology. 2020 Dec;36(4):146-151.
The D antigen is highly immunogenic and may cause alloimmunization to occur after blood transfusion or pregnancy. Some RHD variant alleles express a D antigen that is missing one or more epitopes, thus putting a presumed D+ patient at risk for alloanti-D and hemolytic disease of the fetus and newborn. It is generally accepted that individuals who have a serologic weak D phenotype due to one of three alleles common in Caucasians, RHDweak D types 1, 2, or 3, are not at risk for alloimmunization. In this study, blood samples from 46 obstetrics patients from a local health system were identified based on discrepant results between automated gel and manual tube testing (n = 20) or based on presentation with a serologic weak D phenotype (n = 26). RHD genotyping was performed using commercial and laboratory-developed tests. Of the 26 serologic weak D samples, 18 (69.2%) were found to carry alleles RHDweak D type 1, 2, or 3. The remaining eight samples (30.8%) were found to carry partial D alleles. Of the 20 samples submitted because of D typing discrepancy, 7 (35%) carried alleles RHD*weak D type 1, 2, or 3, while 13 (65%) carried partial RHD alleles. This report summarizes the findings of one hospital system and its approach to integrating RHD genotyping into its assessment of risk of alloimmunization in obstetrics patients. It demonstrates that individuals with partial RHD alleles can present with serologic weak D phenotype, such that, without RHD genotyping, these individuals may not be identified as candidates for Rh immune globulin. The study also demonstrates that use of two methods (automated gel and tube testing) allows for identification of partial D cases that would otherwise be missed. I.
D 抗原具有高度免疫原性，在输血或妊娠后可能会引起同种免疫。一些 RHD 变异等位基因表达的 D 抗原缺失一个或多个表位，从而使假定的 D+患者面临抗 D allo 和胎儿新生儿溶血病的风险。一般认为，由于三种常见的高加索人等位基因 RHDweak D 类型 1、2 或 3 之一导致血清学弱 D 表型的个体不会发生同种免疫。在这项研究中，根据自动化凝胶和手动管检测之间的不一致结果（n = 20）或基于血清学弱 D 表型的表现（n = 26），从当地卫生系统的 46 名产科患者的血液样本中确定了 RHD 基因型。使用商业和实验室开发的测试进行 RHD 基因分型。在 26 例血清学弱 D 样本中，18 例（69.2%）携带 RHDweak D 类型 1、2 或 3 等位基因。其余 8 例样本（30.8%）携带部分 D 等位基因。在因 D 型不一致而提交的 20 个样本中，7 个（35%）携带 RHD*weak D 类型 1、2 或 3 等位基因，而 13 个（65%）携带部分 RHD 等位基因。本报告总结了一个医院系统的发现及其整合 RHD 基因分型方法，以评估产科患者发生同种免疫的风险。它表明，携带部分 RHD 等位基因的个体可能会出现血清学弱 D 表型，如果不进行 RHD 基因分型，这些个体可能不会被确定为 Rh 免疫球蛋白的候选者。该研究还表明，使用两种方法（自动化凝胶和管检测）可以识别否则会错过的部分 D 病例。一。
