Which recipients can be transfused with whole blood type AB?

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

Answer: (A)

When evaluating whole blood compatibility, you must consider both the antigens on donor red cells and the antibodies in the recipient’s plasma. An AB-type donor has red cells with both A and B antigens, but their plasma contains no anti-A or anti-B antibodies. That means the donor’s plasma won’t attack any recipient, but the donor red cells will present A and B antigens. A recipient who has antibodies against those antigens will react to the transfused cells (type A has anti-B, type B has anti-A, type O has both anti-A and anti-B). Only a recipient with no anti-A or anti-B antibodies—the AB type—would tolerate AB donor red cells without an antibody-mediated reaction. So the only recipients who can safely receive whole blood from an AB donor are those with AB blood type. For reference, AB plasma can be given to any recipient, but the red-cell antigens in AB whole blood limit the recipient to AB individuals.