Hemetyypit

Hemetyypit, often translated as "hemotypes," refers to a classification system for classifying blood based on the presence or absence of certain antigens, specifically related to the ABO and Rh blood group systems. This system is fundamental in blood transfusion medicine and in determining compatibility between blood donors and recipients. The ABO system categorizes blood into four main types: A, B, AB, and O, determined by the presence of A antigens, B antigens, both, or neither on the surface of red blood cells. The Rh factor, a separate antigen, is usually classified as positive or negative, indicating the presence or absence of the D antigen.

Combining these two systems results in eight common hemetyypes: A+, A-, B+, B-, AB+, AB-, O+, and O-. Understanding these hemetyypes is crucial to prevent transfusion reactions, which occur when a recipient's immune system attacks transfused red blood cells due to incompatible antigens. For example, a person with A+ blood can receive transfusions from A+, A-, O+, and O- donors. Conversely, O- blood is considered the universal donor type as it can be given to recipients of any hemetyype, lacking both A, B, and RhD antigens. Conversely, AB+ blood is the universal recipient type, capable of receiving transfusions from all other hemetyypes. This precise categorization ensures the safety and efficacy of blood transfusions, a vital medical procedure.