BACKGROUND: Since RhD antigens are highly immunogenic, RhD negative patients should receive RhD negative blood to prevent adverse reaction. Among the RhD variants, the DEL type expresses extremely low D antigens on red blood cells due to mutation of the RHD gene that shows RhD negative results in serologic testing while D antigen is identified in RHD genotyping. Recently, some cases have been reported where anti-D has been induced after being transfused with serological RhD negative blood later identified as DEL type during further investigation (including genotyping). Therefore, we need to prepare an alternative strategy for these cases and in this study, we propose a new safe transfusion strategy for Korean RhD negative patients.
METHODOLOGY: We reviewed cases that induced anti-D by transfusion of DEL type blood and performed RhD typing, weak D testing, Rh C,c,E,e phenotyping and RHD genotyping in 110 samples collected from members of the Gwangju-Jeonnam RhD negative blood donor club. We also conducted a survey among experts about safe transfusion plans for RhD negative patients.
RESULTS/CONCLUSION: In Korea, three cases have been reported in which anti-D was induced in RhD negative recipients due to transfusion of RBCs from Asian DEL type donors. Of the 110 samples, 16 samples were classified as DEL type, and most of them (n=14) were categorized as Asian DEL type. Particularly, 58 samples with ccee phenotype were identified as true RhD negative that has total deletion of RHD gene. In the hospitals, they should diagnose DEL type patients and prepare alternatives in the event of RhD negative blood shortage, such as selective transfusion plans considering high-risk group. In the future, we will continue to establish policies regarding donors and recipients of the DEL type.
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