Blutgruppensysteme

Blutgruppensysteme are classifications of human blood based on the presence or absence of inherited antigenic substances on the surface of red blood cells. These antigens are typically proteins or carbohydrates. The most well-known and clinically significant blood group system is the ABO system, which categorizes blood into types A, B, AB, and O. This system is determined by the ABO gene, which encodes for enzymes that modify a precursor substance. Individuals with type A blood have A antigens, type B have B antigens, type AB have both A and B antigens, and type O have neither.

Another crucial blood group system is the Rh system, most notably the D antigen. Individuals who have the D antigen are considered Rh-positive, while those who lack it are Rh-negative. The combination of ABO and Rh factors results in the commonly recognized blood types such as A+, O-, B+, etc. Transfusion reactions can occur if incompatible blood types are mixed, as the recipient's immune system can produce antibodies against the foreign antigens.

Beyond ABO and Rh, numerous other blood group systems exist, such as Kell, Duffy, Kidd, and MNS. While generally less critical for routine transfusions than ABO and Rh, these other systems can be important in specific clinical situations, particularly for individuals requiring frequent transfusions or those with rare antibody formations. Understanding blood group systems is fundamental to safe blood transfusions, organ transplantation, and the diagnosis and management of certain medical conditions.