When an organ is replaced with someone else’s, the body needs immunosuppressants because of the foreign object now in the body. Why is the same not true for a blood transfusion?

Question

Basically title! I was wondering about this. Thanks!

In: 144

Answer 1

You don’t need immuno-suppressants because we understand how the immune system deals with blood: blood types. On the surface of your red blood cells, there are several different kinds of proteins, which proteins you have and which you don’t determine which blood type you are. Your white blood cells know which proteins you should have and will attack red blood cells with the wrong ones the same way it would attack any other foreign object.