People with A, B, AB, or O blood type mixing can have serious consequences, when A blood is mixed with type B blood the antigens on the type A red blood cells react with the plasma proteins of type B blood. This can lead to antibodies antigen reaction causes clumping of the red blood cells and tends to block blood vessels, resulting in the brain and kidney damage resulting death. O blood are called universal donors, O blood type contains plasma proteins against blood types A and B it can be used in emergency transfusion.
