Clinical Importance and the Prevalence of Kell Group Antigen in Korea according to Ethnicity

The anti-K antibody has a role in transfusion reactions or hemolytic disease of the fetus and newborns. The K antigen is rarely expressed in Koreans. On the other hand, the distribution of blood group antigens has changed in recent years owing to the increased number of immigrants. This study examined the prevalence of the Kell group antigens according to their parents’ birth region. In this study, 4% of participants whose parents were born in America, Europe, South Asia, and other countries expressed the K antigen. No participants whose parents were born in Korea or East Asia expressed the K antigen. The frequency of the anti-K is expected to increase because of blood donors with the K antigen. Therefore, it is necessary to consider the K antigen frequency and anti-K in transfusions and pregnancy cases in Korea. (Korean J Blood Transfus 2021;32:132-134)