If a trauma patient is Group AB and transfused with A RBCs, what is the likely explanation for their reactions?

In this scenario, the trauma patient is blood group AB, which means they have both A and B antigens on the surface of their red blood cells and do not produce antibodies against either A or B antigens. Therefore, when a Group AB patient is transfused with A red blood cells, there will be no immunological reaction.

This is because the AB patient does not possess anti-A or anti-B antibodies, allowing them to safely receive red blood cells from Group A, Group B, or Group O donors without experiencing a transfusion reaction. The absence of antibodies means that the transfused A RBCs will not be attacked by the patient’s immune system, resulting in a compatible and typically safe transfusion.

In contrast, scenarios involving other blood groups or incompatible transfusions would likely lead to a hemolytic reaction, as incompatible antibodies would attack the transfused cells. However, since the patient is Group AB and receiving A RBCs, this situation is entirely compatible.