Genotyping for RhD and RhCEce Antigens Using Free Circulating Nucleic Acids in Plasma and Serum / 대한수혈학회지

ABSTRACT

BACKGROUND: The Rh blood group includes several antigens, of which D, C, E, c, and e are clinically important. Although nucleic acids from whole blood can be used for Rh blood group genotyping, it is also possible to genotype free circulating fetal nucleic acids from plasma and serum. We performed Rh blood group phenotyping and genotyping using nucleic acids from whole blood and free circulating nucleic acids from plasma and serum, respectively. The results were compared. METHODS: Forty-four blood samples were phenotyped and genotyped for RhD and RhCE blood groups. Phenotyping was performed by hemagglutination assay. Further tests were performed on RhD-negative samples. Nucleic acids were extracted from whole blood, plasma, and serum. Plasma and serum were prepared after filtration and genotyped by real-time polymerase chain reaction. RESULTS: RhD blood group results showed one (2.3%) discrepant case in which the DEL phenotype appeared wild RHD genotype. Among nucleic acids, there were seven discrepant results: two from plasma and five from serum based on whole blood nucleic acids. RhCE blood group results showed three (6.8%) phenotype-genotype discordances. Among nucleic acids, seven (15.9%mpared to phenotypes. Kappa coefficients of serum were lower than those of plasma. CONCLUSION: RHD and RHCE genotype could be identified by assaying free circulating nucleic acids in plasma or serum. This study suggests that plasma is more reliable than serum as a specimen for RHD and RHCE genotyping of free circulating nucleic acids.