Verityypit

Verityypit, Finnish for "blood types," refer to the classification of human blood based on the presence or absence of specific antigens on the surface of red blood cells. The two primary systems used in transfusion medicine are the ABO system and the Rh(D) antigen, which together determine compatibility for red blood cell transfusions. Beyond these, many other antigen systems such as Kell, Duffy, Kidd, and MNS contribute to transfusion safety by shaping the risk of alloimmunization, especially in patients requiring multiple transfusions or during pregnancy.

The ABO blood group system was described by Karl Landsteiner in 1901, enabling the first safe transfusions by matching donor and recipient types. The Rh system, defined by the presence or absence of the RhD antigen, was identified in 1940 by Landsteiner and Alexander S. Wiener, and remains essential for determining Rh compatibility. Over the subsequent decades, additional antigen systems were described, further refining transfusion matching.

Typing and testing rely on serological assays that detect antigens on red cells; modern practices also use molecular genotyping to predict antigen expression. Crossmatching tests assess compatibility between donor cells and the recipient’s plasma. In pregnancy, Rh incompatibility is monitored and managed to prevent alloimmunization, for example through antibody screening and, when indicated, prophylaxis with Rh immune globulin.

Verityypit have broad clinical relevance for transfusion practices, organ transplantation, and prenatal care. In emergency situations where a patient’s blood type is unknown, O-negative blood is commonly used after appropriate crossmatching. Ongoing research and genetic testing continue to improve the precision and safety of verityypit matching.