22.28: Blood Transfusion
Blood transfusion is a critical medical procedure that saves lives and treats various medical conditions. It involves transferring blood from a donor to a recipient. This process requires a thorough understanding of the ABO blood group system and its associated antigens and antibodies.
Blood Transfusion Overview
A blood transfusion is a medical procedure used to replace blood lost due to injury, surgery, or to treat conditions such as anemia or cancer. During a transfusion, donor blood is carefully introduced into the recipient's bloodstream. Compatibility between the donor's and recipient's blood is crucial to avoid adverse reactions.
ABO Blood Group System
The ABO system classifies blood types based on the presence or absence of antigens on the surface of red blood cells (RBCs). There are four blood types in this system: A, B, AB, and O.
Agglutination and the Role of Antibodies
Agglutination, or the clumping of RBCs, occurs if a recipient receives blood from a donor with a different blood type. This happens when the recipient's antibodies react with the donor's antigens. For example, if a person with blood type A receives blood from someone with blood type B, the recipient's anti-B antibodies will react with the donor's B antigens, causing agglutination.
O and AB: Universal Donor and Recipient
The O blood group is known as the universal donor because individuals with type O blood lack A and B antigens, so their blood does not react with antibodies in any recipient's blood. Conversely, individuals with the AB blood type are universal recipients because they can receive blood from any donor type without worrying about antibody-mediated agglutination.
Importance of Screening
Although the concepts of universal donor and recipient exist, relying solely on these can be risky. To ensure ideal compatibility, medical professionals conduct screenings using soluble ABO antigens found in bodily fluids like saliva, semen, and sweat or from pinprick peripheral blood samples. This screening helps identify potential incompatibilities, reducing the risk of serious adverse reactions such as hemolysis or anaphylaxis.
In conclusion, understanding the ABO blood group system and careful screening are essential for safe blood transfusions, which are vital in saving lives and treating medical conditions.
