Department of Clinical and Experimental Oncology, Escola Paulista de Medicina/Universidade Federal de São Paulo (EPM/UNIFESP), São Paulo, Brazil.
Department of Pediatrics, Escola Paulista de Medicina/Universidade Federal de São Paulo (EPM/UNIFESP), São Paulo, Brazil.
Vox Sang. 2019 Aug;114(6):605-615. doi: 10.1111/vox.12789. Epub 2019 May 14.
The high homology and the inverted orientation of RHD and RHCE may give rise to non-functional and aberrant RH alleles. RH genotyping is used to screen RH matched donors to African descent patients. This study aimed to define a strategy for testing RHD and RHCE variants in blood donors to provide compatible units for transfusion of patients with haematological diseases.
Samples from 132 patients [101 Sickle cell disease (SCD), 14 myelodysplastic syndrome (MDS), 17 acute myelogenous leukaemia (AML)] and 198 Brazilian donors were studied. Major blood group alleles, RHD, RHCE alleles and RHD zygosity were determined by the blood-MLPA assay. Sequencing was performed to determine RHD and RHCE variant subtypes. A match was an RH genotype that did not encode Rh antigens absent in the patient, along with matching for ABO, MNS, KEL, FY, JK and DI antigens.
Overall, 7·6% of blood donors and 17.4% of patients presented RH genotypes that predict expression of partial Rh antigens or lack of high prevalence Rh antigens. From 23 patients with clinically relevant RH genotypes, 15 had available matched donors.
We report the presence of clinically relevant RH genotypes in SCD and in non-SCD patients. In our admixed population, many patients carry variant RHCE alleles in heterozygosity with normal RHCE alleles. Thus, our results suggest that donors could be selected based on the normal RH allele.
RHD 和 RHCE 的高度同源性和反向排列可能导致非功能性和异常 RH 等位基因。RH 基因分型用于筛选非裔患者的 RH 匹配供体。本研究旨在定义一种检测献血者中 RHD 和 RHCE 变体的策略，以为患有血液系统疾病的患者提供相容的单位用于输血。
研究了 132 名患者（101 名镰状细胞病[SCD]、14 名骨髓增生异常综合征[MDS]、17 名急性髓细胞性白血病[AML]）和 198 名巴西献血者的样本。通过血液-MLPA 分析确定主要血型等位基因、RHD、RHCE 等位基因和 RHD 基因型。进行测序以确定 RHD 和 RHCE 变体亚型。配型是指不编码患者中不存在的 Rh 抗原的 RH 基因型，同时还需要与 ABO、MNS、KEL、FY、JK 和 DI 抗原相匹配。
总体而言，7.6%的献血者和 17.4%的患者出现了预测部分 Rh 抗原表达或缺乏高流行 Rh 抗原的 RH 基因型。在 23 名具有临床相关 RH 基因型的患者中，有 15 名患者有可用的匹配供体。
我们报告了 SCD 和非 SCD 患者中存在临床相关 RH 基因型。在我们的混合人群中，许多患者携带有正常 RHCE 等位基因的杂合变体 RHCE 等位基因。因此，我们的结果表明，可以根据正常 RH 等位基因选择供体。
