Frequencies of ABO and RhD blood groups among blood donors in Hong Kong

Blood transfusion, a life-saving treatment, always requires swift availability of safe blood supply and stringent blood group matching between donor and recipient. Therefore, a better and updated understanding of blood group distribution in the society is necessary for such provision. This study is to determine the latest distribution of ABO, Rhesus D (RhD) blood group among Hong Kong blood donors. A retrospective study of a total of 167,091 new blood donors [including 164,095 Chinese donors and 2,996 non-Chinese donors (NCDs), namely Whites, Indians, Indonesians and Filipinos] from 2011 to 2020. Their ABO and RhD blood groups were determined by automated microplate technique and conventional tube method if needed. Among Chinese donors, blood group of O is the most common ABO blood group at 42.8%, followed by 25.8% being A, 25.5% being B and the remaining 5.9% as AB. For NCDs, though group O remains the most common, group A and B vary with their ethnicities. The RhD positivity is seen in 98.7% Chinese whereas it ranges from 60.6-96.8% in non-Chinese populations. As high as 39.4% RhD negative was observed in the White donors in Hong Kong, which is at least double the prevalence as compared in Western countries. In conclusion, the distribution of ABO and RhD phenotype varies in Chinese and nonChinese residents. With a highly-modernized city with multi-ethnicities, understanding their blood group distribution could enhance the provision of better transfusion service in having sufficient blood of right blood groups to meet clinical transfusion demand.