AB blood can be transfused to which recipients?

• A. AB only
• B. A only
• C. AB and O
• D. All blood types

Answer: (A)

AB blood has both A and B antigens on the surface of red blood cells, and there are no anti-A or anti-B antibodies in the plasma of an AB donor. When you transfuse blood, the recipient’s antibodies can attack donor cells that carry the corresponding antigens. So only a recipient who has no antibodies against A or B will tolerate AB blood without a reaction. That means AB recipients are the only ones who can receive AB blood. Recipients with type A, B, or O blood all have antibodies against at least one of the A or B antigens, which would lead to a transfusion reaction with AB donor cells.