Open AccessRHD alleles among pregnant women with serologic discrepant weak D phenotypes from a multiethnic population and risk of alloimmunization
Author(s) -
Bub Carolina Bonet,
Aravechia Maria Giselda,
Costa Thiago Henrique,
Kutner José Mauro,
Castilho Lilian
Publication year - 2018
Publication title -
journal of clinical laboratory analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.536
H-Index - 50
eISSN - 1098-2825
pISSN - 0887-8013
DOI - 10.1002/jcla.22221
Subject(s) - serology , genotyping , allele , population , phenotype , medicine , typing , genotype , immunology , genetics , gene , biology , antibody , environmental health
Background A considerable number of RHD alleles responsible for weak and partial D phenotypes have been identified. Serologic determination of these phenotypes is often doubtful and makes genetic analysis of RHD gene highly desirable in transfusion recipients and pregnant women. We analyzed the RHD gene in a cohort of pregnant women with doubtful D phenotypes. Methods RHD genotyping was performed on 104 cases with D typing discrepancies or with history of serologic weak D phenotype. Laboratory‐developed DNA tests, RHD BeadChip (Bioarray Solutions, Immucor), and sequencing were used to identify the RHD alleles. Results Molecular analyses showed 23 of 104 (22%) pregnant women were RHD *weak D types 1 , 2 , or 3 and not at risk for anti‐D. Fifty‐one (49%) were RHD *weak partial 4.0, 6 RHD *weak D type 38 (6%), 1 RHD *weak D type 45 (1%), 1 RHD *weak D type 67 (1%), and potentially at risk for being alloimmunized and making anti‐D. Partial D was identified in 22 of 104 (21%) patients and definitively at risk for anti‐D. Discussion Appropriate classification of RhD phenotypes is recommended for correct indication of Rh IG in pregnant women. However, the serologic distinction between RhD‐negative and RhD‐positive phenotypes is a difficult task in the case of D variants due to the variations in serologic testing. Our results show a great variability in RHD variant alleles in pregnant women from this population of high admixture. According to these results, 78% of these obstetric patients are at risk for anti‐D and candidates for Rh IG .