The RhD antigen, which is a highly immunogenic following ABO antigen, can lead to severe hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. It has been known in the past that DEL antigen, which contains very small amount o...
The RhD antigen, which is a highly immunogenic following ABO antigen, can lead to severe hemolytic transfusion reactions and hemolytic disease of the fetus and newborn. It has been known in the past that DEL antigen, which contains very small amount of D antigen does not create anti-D antibodies when transfused to an RhD negative recipient. However, recent reports show that there have been some cases of anti-D antibodies production in an RhD negative patient after having been transfused with DEL type blood component.
In this study, we studied RhD negative red blood cells supplied to our hospital for analyzing the prevalence, phenotype, allele of DEL antigen. Adsorption-elution test, multiplex-polymerase chain reaction (PCR) including exon 4, exon 7, exon 10 and promoter of RHD gene, multiplex ligation-dependent probe amplification (MLPA) and direct sequencing of exon 9 of RHD gene were performed.
In 100 Rhd negative samples with multiplex PCR and MLPA test, 78 showed RHD gene homozygote deletion, 4 showed the RHD-CE-D hybrid, and 18 showed RHD gene heterozygote deletion. In 18 cases with the RHD gene heterozygote deletion were confirmed by adsorption-elution test to be DEL type and the ‘Asian DEL type’ RHD (K409K, 1227G>A) polymorphism was detected by MLPA and direct sequencing of exon 9 of RHD gene in all of 18 cases. In addition, C antigen were expressed in all 18 DEL type in RhCE phenotype analysis (Ccee 14 (77.8%), CcEe 4 (22.2%)).
It is necessary for a newly developed transfusion exanination system, which distinguishes between purely D negative and DEL type blood through RHD gene examination for safer transfusion of RhD negative blood products.