Department of Immunohematology and Blood Transfusion, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, Karnataka, India.
Department of Transfusion Medicine, ICMR-National Institute of Immunohaematology, Mumbai, Maharashtra, India.
Transfus Apher Sci. 2021 Aug;60(4):103142. doi: 10.1016/j.transci.2021.103142. Epub 2021 Apr 20.
RhD expression varies with population and ethnicity. Accurate typing of RhD antigen among blood donors is important to prevent development of anti-D among recipients of blood transfusion. We aimed to screen blood donors for variant D phenotypes and accurately characterize them by genotyping.
We have done prospective study on blood donors by performing RhD typing using three different commercial monoclonal anti-D reagents by both column agglutination and conventional tube techniques. Samples that showed ambiguous results were further screened with the Bio-Rad Partial RhD typing kit. Minor phenotyping for C, c, E, e antigens was performed. Multiplex PCR and Sequencing of all RHD exons with Sanger's sequencing was performed for molecular characterization of variant D.
A total of 16,974 blood donors were screened during the study period. Among them, 31 (0.18 %) donors were found to have a RhD variant phenotype. The male to female ratio was 10:1. The presence of 'C' antigen was noted among all RhD variant samples. Serological typing identified two samples as DV phenotype and the rest could not be characterized. Molecular genotyping characterized 90.3 % of the samples as Indian specific weak D type 150 variants. Three samples were subjected to Sangers sequencing and showed wild type pattern.
The present study showed that the most common variant in this population was Weak D type 150. This study highlights that serological methods may serve as a screening tool, however, molecular techniques are essential for characterization of RhD variants.
RhD 表型因人群和种族而异。准确鉴定献血者的 RhD 抗原对于预防输血受者产生抗-D 至关重要。我们旨在通过基因分型筛选献血者中的变异 D 表型，并对其进行准确特征描述。
我们前瞻性地研究了献血者，使用三种不同的商业单克隆抗-D 试剂通过柱凝集和常规试管技术进行 RhD 分型。对显示不确定结果的样本进一步用 Bio-Rad 部分 RhD 分型试剂盒进行筛选。进行 C、c、E、e 抗原的次要表型检测。对所有 RHD 外显子进行多重 PCR 和 Sanger 测序，以对变异 D 进行分子特征描述。
在研究期间，共筛选了 16974 名献血者。其中，31 名（0.18%）献血者存在 RhD 变异表型。男女比例为 10:1。所有 RhD 变异样本均存在“C”抗原。血清学分型将两个样本鉴定为 DV 表型，其余样本无法鉴定。分子基因分型将 90.3%的样本鉴定为印度特有的弱 D 型 150 变异。三个样本进行了 Sanger 测序，显示出野生型模式。
本研究表明，该人群中最常见的变异是弱 D 型 150。本研究表明，血清学方法可作为筛选工具，然而，分子技术对于 RhD 变异的特征描述是必不可少的。
