Comment by pkaye

I'm a kidney transplant patient myself. Your cells have HLA markers to distinguish your own cells from foreign cells. That is to prevent your immune cells from attacking your own body. This also makes it harder to find a organ match.

The reason I needed a kidney transplant is because of an auto disease called IgA Nephropathy where the IgA antibody has a small defect that causes the rest of the immune system to attack it and the whole mess clogs up the kidney filters over time.