Blood transfusion

In case of a blood transfusion, it is highly important to match the donated blood with the blood type of the patient. For this reason, ABO type and Rhesus (Rh) status must be taken into consideration when transferring blood to a patient. Receiving the wrong blood type leads to agglutination of the red blood cells and other immunological complications. This can be lethal for the patient.

Agglutination

Agglutination is the clumping of particles. The process of red blood cells agglutination is called hemagglutination.

Clots is a technical term but a different process to agglutination (clotting includes a clotting cascade fibrin and platelets whereas agglutination is usually an Antibody and antigen sticking together(e.g. agglutination).

Blood agglutination occurs when an antibody reacts with the specific antigen on the cell surface of red blood cells. For example, if blood from a donor with blood group A is given to a patient with blood group B, existing anti-A antibodies in the patient would bind to the A antigen on the donor's red blood cells. This causes agglutination or blood clotting in the patient's veins, which can be life-threatening. It is therefore absolutely essential to test every donor's and patient's blood group with a blood typing test before transfusion is carried out.

Compatibility

In the table below you have a summary of what types of blood can be received or donated among different blood types. According to the table, AB+ is the “universal receptor”, since they can receive any type of blood and O- is the “universal donor”, as they can donate their blood to any person without the risk for agglutination.