Blood type Blood Transfusion in addition to the common ABO and Rh systems. Thus, in addition to the ABO antigens and Rh antigens, many other antigens are expressed on the RBC surface membrane. For example, an individual can be AB, D positive, and at the same time M and N positive (MNS system), K positive (Kell system), Le or Le negative (Lewis system), and so on, being positive or negative for each blood group system antigen. Many of the blood group systems were named after the patients in whom the corresponding antibodies were initially encountered. Transfusion medicine is a specialized branch of
Rh blood group system respect, genotyping of blood groups has much simplified this detection of the various variants in the Rh blood group system. It is important to differentiate weak D (due to a "quantitative" difference in the D antigen) from partial D (due to a "qualitative" difference in the D antigen). Simply put, the weak D phenotype is due to a reduced number of D antigens on a red blood cell. In contrast, the partial D phenotype is due to an alteration in D-epitopes. Thus, in partial D, the number of D antigens is not reduced but the protein structure is altered. These