Why is ABO compatibility important in transfusion?

• A. It prevents contamination
• B. It ensures faster transfusion
• C. It reduces risk of immune reaction by matching donor antigens with recipient antibodies
• D. It improves taste of the blood product

Answer: (C)

The key idea is preventing an immune reaction by matching donor blood antigens with what the recipient’s immune system already recognizes as foreign. People naturally have antibodies against ABO antigens they do not possess. If the transfused red cells carry A or B antigens that the recipient’s antibodies will attack, those antibodies bind to the donor cells, causing agglutination and rapid hemolysis. This immune attack can lead to serious, life‑threatening reactions, including shock, kidney injury, and widespread inflammation. Because ABO antigens are highly immunogenic and located on the surface of red blood cells, ensuring compatibility is essential. That’s why labs perform ABO typing and crossmatching before transfusion. The other options don’t fit because contamination, faster transfusion, or taste are not addressed by ABO matching.