A study has shown that blood type distribution varies by race and region. In East Asia, including Korea, Japan, China, and Taiwan, the proportion of type AB is relatively high compared to Europe, the Middle East, and Africa; however, the percentage of RhD negative (-) is extremely low. Considering these characteristics, patient treatment should be adjusted to reduce side effects, but there is an opinion that Korea's blood transfusion system is oriented towards Westerners and needs improvement.
Samsung Medical Center noted on the 29th that "a research team led by Professor Cho Deok of the Department of Laboratory Medicine at Samsung Medical Center, resident Yoon Se-hyo from Harvard Medical School's Pathology Department, and Professor Lim Ha-jin from Chonnam National University Hospital analyzed the ABO and RhD blood type characteristics worldwide, yielding these results." The research paper was published last month in the international journal "Transfusion."
ABO blood type is determined based on the A and B antigens present on the surface of red blood cells. If the A antigen is present, it is type A; if the B antigen is present, it is type B; if both antigens are present, it is type AB. If neither antigen is present, it is type O. RhD blood type is separate and is classified as Rh+ if the RhD antigen (D antigen) is present on the surface of the red blood cells, and Rh- if the D antigen is absent. When combining the two blood types, type A is marked as A+ if RhD is positive and A- if RhD is negative.
The study found that in the East Asia region, type AB accounts for 5 to 12%, while RhD- accounts for 0.1 to 1%. Conversely, in Europe, type AB is 3 to 8%, and RhD- ranges from 11 to 19%. The researchers stated that because blood type distribution varies by race and region, different transfusion systems are needed.
It is essential to check blood types when performing a transfusion. If type A blood is given to a person with type B blood, an immune rejection occurs due to an antigen-antibody reaction. This is because type A has A antigens, and type B has anti-A antibodies. The anti-A antibodies perceive the A antigens as intruders and attack.
There are blood types that are free from this problem. Type O, and specifically RhD-, has no antigens, allowing it to be used immediately in emergency patients with severe bleeding without blood type testing. The issue is that while such O- blood is easy to obtain in Europe, it is scarce in Korea. Researchers explained that in Korea, O+ blood is sometimes used, which carries significant risk.
Additionally, the variant blood type cis-AB is common in Korea and Japan but not in Europe, the Middle East, or Africa. The researchers pointed out that some domestic equipment may incorrectly diagnose cis-AB as type AB. Since the equipment was developed in the West, recognizing cis-AB is not easy. If type AB blood is transfused to a patient with cis-AB, an antigen-antibody reaction may occur, leading to the destruction of red blood cells and dissolution in the blood.
The researchers said, "This study demonstrates that existing Western-centered transfusion standards are not universal, and Korea needs blood type genetic testing methods that suit East Asian characteristics."
References
Transfusion (2025), DOI: https://doi.org/10.1111/trf.18253