What Is the Universal Recipient Blood Type?

Understanding Universal Donors and Recipients

Human blood for transfusion in Boston
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You are probably aware that giving a person a blood transfusion with the wrong type of blood can be lethal, leading to rejection and often death, but you may not be aware that some individuals can safely receive blood from a donor with any blood type.  A person who can accept a blood transfusion from any blood type is called a universal recipient.

Universal recipients can receive a blood transfusion from a person with any blood type. To put it another way, the immune system of a person with AB blood will accept blood from all possible donors, whether they have O, A, B, or AB blood.  

So how is it that the rarest blood type is also the one that is a universal recipient? The answer lies in the antigens that are present in most blood types. O blood types are unique in that they have no antigens. A blood types have an antigen that is specific and unique to A blood, as do B blood types. The AB blood type means that both of the antigens for A and B blood are both present.

Since both A and B antigens are present in a person with AB blood, the recipient won't reject the blood. The body identifies that blood as "self" rather than "foreign." O blood has no antigens and is referred to as universal donor blood, so that will not cause a reaction. So, a person with AB blood has all of the antigens that are possible, and an O negative person has no antigens that would cause a reaction.  

Reaction to a Blood Transfusion

Keep in mind that there is a difference between a reaction caused by transfusing the wrong type of blood, which can be and often is fatal, and an allergic reaction to the blood transfusion, which is possible regardless of blood type. 

An allergic reaction to a blood transfusion is not caused by a blood type mismatch; it is caused by the recipient's body identifying the blood as "foreign." The immune system then attempts to destroy the foreign cells. Also known as an acute hemolytic transfusion reaction, this type of reaction typically results in itching, fever, chills, itching, and a rash. It typically passes in 24-48 hours and is usually treated by stopping the transfusion and administering a dose of Benadryl or another histamine reducing agent to reduce the reaction.  

Unlike the reaction that happens when the wrong blood type is given, the reaction the body has to blood that is identified as "foreign" can typically be treated effectively if identified and treated.  An individual who has this type of reaction may require more thoroughly screened blood in the future to prevent a similar reaction with subsequent transfusions, if there is a need for additional blood.

Organ Donation and Universal Recipients

Receiving a blood transfusion is not the only time that being a universal recipient matters. An individual who needs an organ transplant could also potentially benefit from being a universal recipient.

If a patient has the AB blood type and needs an organ, they could accept an organ from donors of all blood types, just as they an accept blood of any type. The process of matching a donor and recipient is more complicated than that and requires matching beyond just compatible blood types. For this reason,  a donor and recipient may not be compatible, but, generally speaking, a person with the AB blood type can receive an organ from a donor of any blood type.

The organ allocation system is also set up so that the allocation of organs is fair, and AB recipients don't receive an unfair percentage of organs while recipients with other blood types receive less.  UNOS, the organization that allocates organs, works very hard to make sure that organs go to recipients in a way that is fair for individuals of all blood types, races, ages and conditions. 

A Word From Verywell

Individuals with AB blood are fortunate enough to be able to accept blood from donors of all blood types.  While this is an interesting fact, there is typically an adequate blood supply for anyone with a need--regardless of their blood type--on any given day.  Blood donations from a generous community makes it possible for a patient of any blood type, rare or otherwise, to benefit from a transfusion of blood when needed.