The prevalence of selected clinically significant red blood cell antigens among Australian blood donors.

ABSTRACT

Red blood cell (RBC) transfusion can cause some patients to form antibodies to RBC antigens when RBC phenotypes do not match that of the blood donor. Transfusion practitioners can order phenotyped RBC units for patients with known RBC antibodies or those who are at risk of forming them. However, with increasing demand for phenotyped RBC units, contemporary data on antigen prevalence is required to manage the changing supply. A total of 490,491 blood donors, including 103,798 (21.2%) first-time blood donors, from 2019 were analysed for the prevalence of selected clinically relevant blood group antigens. Prevalence of the phenotype R1R1 (D+ C+ E- c- e+) increased from the previous estimate of 17.3% to 24.0% in first-time blood donors. The prevalence of R1r (D+ C+ E- c+ e+) decreased from 35.3% to 30.8%. R1R1 was more common in blood donors born in Asia or the Middle East. The prevalence of Fy(a-b-) in donors where Fy antigens were tested was 0.2%. Of these, 71.8% stated their region of birth as Africa. The prevalence of Jk(a-b-) is 0.01% in donors where the Jk antigens were tested with region of birth stated as either Oceania or Asia. The increasing prevalence of the c-negative phenotype in R1R1 individuals is associated with the changing demographics of the Australian community. For R1R1 individuals with childbearing potential, the transfusion of RhD negative blood, which is usually c-positive, may increase the possibility of haemolytic disease of the fetus and newborn during pregnancy. Continued diversification of the Australian blood donor panel will support having the appropriate phenotyped RBC units available.