Sección Hematología e Inmunohematología, Departamento Laboratorio Biomédico Nacional y de Referencia, Instituto de Salud Pública de Chile, Santiago, Chile.
Subdepartamento de Genética Molecular, Departamento Laboratorio Biomédico Nacional y de Referencia, Instituto de Salud Pública de Chile, Santiago, Chile.
Front Immunol. 2023 Dec 5;14:1299639. doi: 10.3389/fimmu.2023.1299639. eCollection 2023.
The D antigen variants are classified as weak, partial, and extremely weak (DEL) and can be differentiated using molecular tests. In Chile, the laboratories of local blood centers do not identify variants of the D antigen, referring them for study to the Reference Laboratory of the Public Health Institute of Chile. So, our aim was to talk about the results of the molecular analysis of variants of the D antigen in samples that had different results in the serological classification.
In the D antigen classification of the Rh system, 479 samples with serological discrepant results were sent for molecular analysis. The Rh phenotype was performed with monoclonal anti-C, anti-c, anti-E, and anti-e antisera by direct agglutination. To find the D antigen, researchers used direct agglutination with monoclonal antisera and indirect antiglobulin testing with the column (gel) agglutination method. Molecular analysis was performed with a polymerase chain reaction with sequence-specific primers (SSP-PCR) and sequencing.
The presence of D antigen variants was confirmed in 332 samples (69.3%), with an initial discrepancy in serological classification. In this group of discrepant samples, the frequency of weak RhD variants was 66% (219/332), that of extremely weak RhD was 28% (93/332), and that of partial RhD was 6% (20/332). The weak variants type 2 (27.4%), type 3 (8.4%), type 48 (8.4%), and type 1 (8.1%) were the next most prevalent variants after RHDDEL43 (28%). The ccEe (R2r) phenotype was the most frequently detected (38.4%) and is present in 87% of the RHDDEL43 samples. The E antigen is associated with the presence of this variant. Our analyses give the first description of D antigen variants in Chile. The most common variants are DEL type (RHD*DEL43) and weak (weak type 2), which are linked to the ccDEe (R2r) phenotype. These findings allow us to characterize the variants of the D antigen in Chile and, according to the obtained data, to design strategies for the management of donors, patients, and pregnant women.
D 抗原变体分为弱型、部分型和极弱型（DEL），可通过分子检测进行区分。在智利，当地血液中心的实验室不识别 D 抗原变体，而是将其转介给智利公共卫生研究所的参考实验室进行研究。因此，我们的目的是讨论在血清学分型中出现不同结果的样本中 D 抗原变体的分子分析结果。
在 Rh 系统的 D 抗原分类中，将 479 份血清学结果不一致的样本送检进行分子分析。Rh 表型采用直接凝集法与单克隆抗-C、抗-c、抗-E 和抗-e 抗血清进行检测。为了发现 D 抗原，研究人员采用单克隆抗血清进行直接凝集和柱（凝胶）凝集间接抗球蛋白试验。分子分析采用聚合酶链反应序列特异性引物（SSP-PCR）和测序。
在 332 份（69.3%）有初始血清学分型差异的样本中，确认存在 D 抗原变体。在这组不一致的样本中，弱 RhD 变体的频率为 66%（219/332），极弱 RhD 变体的频率为 28%（93/332），部分 RhD 变体的频率为 6%（20/332）。其次是常见的变体是 RHDDEL43（28%），其次是弱变体 2 型（27.4%）、3 型（8.4%）、48 型（8.4%）和 1 型（8.1%）。ccEe（R2r）表型是最常见的（38.4%），87%的 RHDDEL43 样本存在该表型。E 抗原与该变体的存在有关。我们的分析首次描述了智利的 D 抗原变体。最常见的变体是 DEL 型（RHD*DEL43）和弱型（弱型 2），它们与 ccDEe（R2r）表型有关。这些发现使我们能够描述智利的 D 抗原变体，并根据获得的数据设计供体、患者和孕妇管理策略。
