Type AB blood can donate to which recipients?

• A. Everyone
• B. Type O
• C. AB only
• D. A and AB only

Answer: (C)

Blood compatibility in transfusions depends on which A and B antigens are on donor red blood cells and which antibodies are present in the recipient’s plasma. Type AB red blood cells have both A and B antigens on their surface and, importantly, contain no anti-A or anti-B antibodies in their plasma. The key is that a recipient’s plasma antibodies would attack donor cells that have antigens they recognize. Since AB individuals lack antibodies against A or B, AB red cells are only safely given to AB recipients. Donating AB blood to everyone would trigger reactions in recipients with anti-A or anti-B antibodies, such as those with type O, A, or B blood. Therefore, AB blood can be donated only to AB recipients.