Which blood group is known as universal donor?

Appeared in: NORCET 5 Prelims - Sept 2023 (Shift-2)

Explanation

Blood group O is called the 'universal donor' because its red blood cells (RBCs) have no antigens (neither A nor B) on their surface.
The absence of these antigens means the recipient's immune system will not produce antibodies to attack the transfused blood.
This allows O group blood to be given to people with any other ABO blood type (A, B, AB, or O) without causing an adverse transfusion reaction.

Option A: Blood group A has A antigens on its RBCs and anti-B antibodies in the plasma. It cannot be given to a person with blood group B or O, as their anti-A antibodies would cause a reaction.
Option B: Blood group B has B antigens on its RBCs and anti-A antibodies in the plasma. It cannot be given to a person with blood group A or O, as their anti-B antibodies would cause a reaction.
Option C: Blood group AB has both A and B antigens on its RBCs. It can only be donated to another person with blood group AB. It is known as the 'universal recipient', not the universal donor.

Visual 1: Diagram: ABO Blood Group System. An infographic showing the four blood types (A, B, AB, O) with their corresponding antigens on red blood cells and antibodies in the plasma. Arrows should indicate donation and reception pathways, highlighting O as the universal donor and AB as the universal recipient.

Clinical Relevance

Nursing practice connection: Knowing ABO blood grouping and transfusion compatibility helps nurses interpret findings accurately and avoid errors in routine assessment, medication administration, and patient teaching.
In emergency situations where the patient's blood type is unknown, O-negative blood is the first choice for transfusion because it is the most compatible with all other blood types.
The concept of universal donor and recipient is fundamental to safe blood transfusion practices, preventing potentially fatal hemolytic transfusion reactions.
What if? If a patient with blood type B receives blood from a type A donor, the recipient's anti-A antibodies will attack the donor's A-antigen-carrying red blood cells, leading to agglutination, hemolysis, and potentially kidney failure or death.

How to Approach the Question

Identify the key term in the question: 'universal donor'.
Recall the definition of a universal donor in the context of blood transfusions: a blood type that can be given to anyone, regardless of their own blood type.
Analyze the ABO blood group system. Remember that antigens on the surface of red blood cells trigger immune reactions.
The universal donor must lack the antigens that would cause a reaction in recipients. Blood group O has no A or B antigens.
Therefore, select the option corresponding to the blood group that lacks A and B antigens.

Concept Tested & Keywords

QK0VPhO35PDopDuVxRPer0

Practise the full NORCET 5 Prelims - Sept 2023 (Shift-2)

Attempt every question from this paper in a timed mock, then review the full solution for each one.