In a blood transfusion context, which antigen typing is critical for preventing incompatibility reactions?

In the context of blood transfusions, the ABO antigen typing is critical for preventing incompatibility reactions. The ABO blood group system consists of antigens A and B, and individuals can have type A, type B, type AB, or type O blood based on the presence or absence of these antigens. When a person receives blood that contains antigens foreign to their own, the immune system may recognize these antigens as harmful, leading to a potentially life-threatening hemolytic transfusion reaction.

Ensuring that the donor's and recipient's blood types are compatible is essential, which is why ABO typing precedes any transfusion. For example, a person with type A blood should not receive type B or AB blood, as their immune system would attack the foreign B antigens, resulting in serious complications.

While other antigen typings, such as Rh factor, are also important in the context of blood transfusions (particularly in avoiding Rh incompatibility during pregnancy or subsequent transfusions), the initial compatibility primarily hinges on the ABO blood group system. Therefore, ABO typing directly addresses the most immediate compatibility issues encountered in blood transfusions, making it a critical focus for preventing adverse reactions.