Prospects for the provision of genotyped blood for transfusion.

Blood group genotyping is gaining widespread adoption in blood centres and transfusion services. The current interest for a blood centre is its use as a screening tool to accurately predict donor phenotypes. However, not only is blood group genotyping used to screen for uncommon and rare types on a mass-scale, it can be used to optimize the inventory of multiple antigen-negative screened units. In addition, blood group genotyping provides blood types when antisera are not available, it can predict weak and variant antigens, and can aid in the resolution of ABO discrepancies. There are quality improvement benefits in blood group genotyping because it can screen for RHD alleles in Rh-negative blood donors and can be used to confirm that donors are suitable for reagent red cell production. It is possible that blood group genotyping information may be used as a donor recruitment tool. Given that genotyping can convey much more information about the expression of some complex antigens, e.g. hrB, Uvar, and Duffy, clinical trials are probably needed to show that genotyped or 'dry matched' transfusions are superior to phenotyped blood.