Karger Publishers, Transfusion Medicine and Hemotherapy, 1(42), p. 15-21, 2015
DOI: 10.1159/000370217
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<b><i>Background: </i></b>The D antigen is highly immunogenic, requiring only a small quantity of transfused red blood cells (RBCs) to cause alloimmunization in D- immunocompetent recipients. DEL was reported arousing alloimmunization to true Rh- patients. Molecular studies of the <i>RHD </i>gene have revealed that DEL individuals retain a grossly intact <i>RHD </i>gene or have a portion of <i>RHD </i>in their genomes. Avoiding immunization with clinically important antibodies is a primary objective in transfusion medicine. <b><i>Methods:</i></b> In order to determine whether pregnant DEL women carrying an RhD+ fetus are at risk of anti-D alloimmunization, 808 Rh- pregnant women with a history of gestations or parturitions who regularly visited hospitals for their prenatal anti-D screening and postpartum care from January 2011 to December 2012 were investigated. Samples were analyzed for DEL by PCR with specific primers, PCR-sequence-specific primers (PCR-SSP), reverse transcription-PCR (RT-PCR), PCR-restriction fragment length polymorphism (PCR-RFLP), and by gene sequencing to characterize different alleles. <b><i>Results: </i></b>Among the 808 Rh- pregnant women of our sample, 178 (22.0%) were typed as DEL; 168 DEL samples were confirmed to have the <i>RHD </i>(1,227 G>A) allele, 8 DEL samples were characterized by one base mutation of the<i> RHD </i>(3G >A) allele, and the remaining two DEL samples were determined to carry<i> RHD-CE(4-9)-D</i> or RHD-CE(2-5)-D. The observation of allo-anti-D in two prominent D epitope loss cases confirmed the partial nature of these DEL phenotypes. <b><i>Conclusions: </i></b>In conclusion, evidence is provided that different <i>DEL</i> genotypes code either for partial or complete D antigen expression. It is suggested that the use of RhD+ RBCs in complete D antigen DEL patients does not induce adverse reaction.