RBCAntigene

RBCAntigene is a term used in transfusion medicine to refer to the set of antigenic determinants expressed on the surface of human red blood cells. These determinants define the blood group status of an individual and influence compatibility for transfusion and transplantation. The best known RBCAntigene systems are ABO and Rh, but many others exist, including Kell, Duffy, Kidd, and MNS. The aggregate of RBC antigens varies among individuals, driving alloimmunization risk when antigen-positive recipients are exposed to antigen-negative donor cells.

Most RBCAntigene are carried by glycoproteins or glycolipids embedded in the RBC membrane; some are protein-based, others are carbohydrate structures. The ABO antigens, for example, are carbohydrate determinants formed by specific glycosyltransferase activities that modify the H antigen. Rh antigens largely reflect membrane proteins encoded by the RHD and RHCE genes. Minor antigen systems arise from a variety of gene loci, each contributing to antigenic variation.

Clinical relevance centers on transfusion safety and obstetric risk. Matching for ABO and Rh(D) reduces hemolytic transfusion reactions and severe HDFN. In patients requiring chronic transfusion, extended antigen typing or genotyping can minimize alloimmunization by selecting antigen-negative units.

Typing and testing employ serologic methods and molecular genotyping to determine an individual's RBCAntigene profile and to confirm donor-recipient compatibility. The concept dates to the discovery of the ABO system by Karl Landsteiner in 1901, with later recognition of the Rh system in the mid-20th century.