Final answer:
Blood type AB is transfused to AB individuals because they are universal recipients and do not produce antibodies against A or B antigens. If AB blood is unavailable, blood types A or B are preferred, followed by O blood as a last resort, despite being a universal donor, due to the presence of anti-A and anti-B antibodies in O blood plasma.
Step-by-step explanation:
It is recommended to transfuse blood type AB to a person with AB blood because individuals with type AB blood are known as universal recipients. They can theoretically receive blood from any ABO blood type since they have both A and B antigens on their erythrocyte surfaces and do not produce anti-A or anti-B antibodies. When AB blood is unavailable, the next best options are blood types A or B.
If neither AB, A, nor B blood types are available, as a last resort, type O blood, the universal donor, can be used. Type O blood does not have A or B antigens on the erythrocytes, making it less likely to provoke an immune response in the recipient. However, it's important to note that type O blood contains antibodies against both A and B antigens, which could have negative implications for the recipient, although typically limited because the volume of transfused blood is much smaller than the recipient's own blood volume.