ABO Blood Group System
Going back in history, it was not until the year 1900, when Austrian scientist Karl Landsteiner discovered why some blood transfusions were successful while others deadly. Ever since these discoveries have led to safer transfusion practices. The principle is based on division into four main groups (A, B, O, and AB) due to the agglutination patterns of the red blood cells. Type O blood is the most prevalent worldwide and considered a “universal donor”. Type AB individuals are “universal recipients”, and type AB plasma is compatible with all other ABO blood types. The most common cause of death during a transfusion is a clerical error, where an incompatible unit of blood was transfused. Acute hemolytic transfusion reactions can occur within 24h and most commonly happen with transfusion of red blood cells, although they can develop with transfusions of other blood products.