Blood type

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Blood_Type_Compatability

Blood type, also known as blood group, is a classification of blood based on the presence or absence of specific antigens on the surface of red blood cells (RBCs). There are various blood group systems, but the most significant and widely used are the ABO blood group system and the Rh blood group system. These antigens determine compatibility in blood transfusion and are also involved in certain disease risks and immune responses.

ABO_blood_type

ABO blood group system[edit | edit source]

The ABO blood group system classifies blood into four types: A, B, AB, and O. The system is based on the presence or absence of A and B antigens on the surface of red blood cells. Blood type O lacks these antigens, while blood type AB has both. A and B antigens can also be found in other body fluids and tissues.

BloodDonorsAndReceivers

Type A[edit | edit source]

Type A blood contains A antigens on the surface of the red blood cells and anti-B antibodies in the plasma. People with this blood type can receive blood from type A or type O donors, but not from type B or AB donors. They can donate blood to type A and AB recipients.

Type B[edit | edit source]

Type B blood contains B antigens on the surface of the red blood cells and anti-A antibodies in the plasma. Individuals with this blood type can receive blood from type B or type O donors, but not from type A or AB donors. They can donate blood to type B and AB recipients.

Type AB[edit | edit source]

Type AB blood has both A and B antigens on the surface of the red blood cells and no antibodies in the plasma. This blood type can receive blood from any ABO blood group, making them universal recipients. However, they can only donate blood to type AB recipients.

Type O[edit | edit source]

Type O blood lacks A and B antigens on the surface of the red blood cells and has both anti-A and anti-B antibodies in the plasma. This blood type can donate blood to any ABO blood group, making them universal donors. However, they can only receive blood from type O donors.

Rh blood group system[edit | edit source]

The Rh blood group system is another significant blood group system, based on the presence or absence of the RhD antigen. People with the RhD antigen are considered Rh-positive (Rh+), while those without it are Rh-negative (Rh-). Rh-negative individuals can only receive blood from Rh-negative donors, while Rh-positive individuals can receive blood from both Rh-positive and Rh-negative donors.

Blood type compatibility[edit | edit source]

Blood type compatibility is crucial in blood transfusion, organ transplantation, and during pregnancy, as mismatched blood types can lead to serious complications. The following table shows the compatibility between different ABO and Rh blood groups:

Kell_and_extended_Rh_antigen_blood_typing

Blood type distribution[edit | edit source]

The distribution of blood types varies among populations and ethnic groups. Blood type O is the most common globally, while type AB is the least common. Type O is particularly prevalent in Central and South America, while type A is more common in Europe and parts of Asia. Type B is relatively more common in Asia and Africa.

Blood type and disease risk[edit | edit source]

Some blood types are associated with an increased risk of certain diseases. For example, blood type A individuals have a higher risk of developing gastric cancer compared to other blood types. On the other hand, blood type O individuals have a higher risk of developing peptic ulcer disease.

Blood type and pregnancy[edit | edit source]

Blood type compatibility is essential during pregnancy to prevent hemolytic disease of the newborn (HDN). HDN occurs when the mother's Rh-negative blood produces antibodies against the Rh-positive blood of the fetus, causing red blood cell destruction in the fetus. This condition is preventable by administering Rh immunoglobulin (RhIg) to the Rh-negative mother during pregnancy and after delivery.

Determining blood type[edit | edit source]

Blood type can be determined through blood typing, a laboratory test that involves mixing the blood sample with specific antisera to determine the presence or absence of particular antigens. This test is performed before blood transfusion or organ transplantation to ensure compatibility between the donor and the recipient.

See also[edit | edit source]

Summary[edit | edit source]

In summary, blood type is a category used to describe a person's blood according to the kinds of proteins present on the surface of the red blood cells.


Blood type Resources
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Contributors: Prab R. Tumpati, MD