group

Blood groups are classified based on the presence or absence of specific antigens on the surface of red blood cells and antibodies in the plasma. The two most important systems used worldwide are the ABO system and the Rh system, but there are many others recognized for clinical and scientific purposes.

🩸 Major Blood Group Systems

1. ABO Blood Group System
– A: Has A antigens on red cells and anti-B antibodies in plasma.
– B: Has B antigens and anti-A antibodies.
– AB: Has both A and B antigens, no antibodies.
– O: Has no antigens, but both anti-A and anti-B antibodies.
– Most critical for transfusions and organ transplants.

2. Rh (Rhesus) Blood Group System
– Rh Positive (Rh⁺): Has the RhD antigen.
– Rh Negative (Rh⁻): Lacks the RhD antigen.
– Important in pregnancy and transfusion compatibility.

🧬 Other Recognized Blood Group Systems

The International Society of Blood Transfusion (ISBT) recognizes 43 blood group systems, including:

1. MNS- M, N, S, s, U (Involved in transfusion reactions)
2. Kell- K, k (Can cause hemolytic disease of the newborn)
3. Duffy- Fya, Fyb (Associated with malaria resistance)
4. Kidd- Jka, Jkb- Important in delayed transfusion reactions)
5. Lutheran- Lua, Lub (Rarely causes transfusion issues)
6. Lewis- Lea, Leb (Found in secretions and plasma)
7. P- P1, Pk (Linked to rare hemolytic reactions)