Why does our body reject other people’s donated organs and require immunosuppressants to be taken but getting someone else’s blood is ok?

Question

Why does our body reject other people’s donated organs and require immunosuppressants to be taken but getting someone else’s blood is ok?

In: 157

Answer 1

Unlike other cells in your body, red blood cells do not have a nucleus, and do not have DNA. They do not synthesize RNA and do not engage in synthesis of proteins. They have no ribosomes and no mitochondria (and so no mitochondrial DNA) either.

In other words, a red blood cell from one person is pretty much functionally identical to a red blood cell from another person, provided they are the same blood type. They don’t keep pumping out a lot of the mismatched stuff that an organ would over time, and that your immune system would identify and attack as foreign.

Other blood cells like white blood cells (leukocytes) do have their DNA and do get rejected, but these generally don’t live very long already, and are not the “point” of a blood transfusion to begin with. So their loss is not particularly noticed.