Relative immunogenicity of blood group antigens: First report in a Korean population.

BACKGROUND: The immunogenicity of a blood group antigen is a measure of its likelihood of inducing alloantibodies. Although the immunogenicity of blood group antigens has been analyzed in Caucasian populations, immunogenicity to date has not been analyzed in Asian subjects. The present study therefore evaluated the relative immunogenicity of blood group antigens in a Korean population. STUDY DESIGN AND METHODS: All available data of unexpected antibody identification tests performed at Asan Medical Center between 1997 and 2021 were analyzed. The relative immunogenicity of a blood group antigen relative to K antigen was calculated based on relative numbers of alloantibodies and the probabilities of antigen-negative recipients receiving antigen-positive RBC units. RESULTS: A total of 3898 antibody identification results were included, with 1632 (41.9 %) from male patients. The ranking of antigen immunogenicity was: E > c > e > C > K > Jk(a) > Lu(a) > S > Fy(a) > Fy(b) > Jk(b) > Di(b) > Di(a) in the total population and E > c > e > C > Jk(a) > Fy(a) > Fy(b) > S > K > Lu(a) > Jk(b) > Di(b) > Di(a) in male patients. DISCUSSION: The rank order of immunogenicity for blood group antigens in this study provides information about relative immunogenecity in Koreans. These findings also provide supporting evidence regarding antigen selection for extended antigen-matched transfusions in recipients of multiple transfusions.