Kidneys are compared according to blood type. The process of matching blood types of blood donors to their blood type is known as “cross-testing.” The table below shows which blood groups match (are compatible). Kidney donors must have a blood group compatible with the recipient. The Rh (+ or -) factor of the blood does not matter in a transplant.
Except for identical twins and some siblings, it is rare to find a six-antigen match between two people, especially if they are not related. Kidneys are very successfully transplanted between two people without matching antigens. A person can produce antibodies to another person's HLA antigens. Antibodies can result from blood transfusions, pregnancy, infections, or even a viral disease.
Having one of these events doesn't mean a person will produce antibodies, but they might. If a recipient has strong antibodies to a donor's HLA, the risk of rejection is high and a donor would be rejected for that recipient. The recipient's body will always see an organ as a foreign object. If a deceased donor and a transplant recipient do not share the same blood type, a transplant will not be performed.
When a living donor and a transplant recipient do not share the same blood type, the recipient may undergo special treatment to calm the immune system and allow the recipient to accept the kidney that is incompatible with the living donor's blood group. Without this treatment, the recipient's body will reject the new kidney, resulting in failure of the transplant. Once blood type compatibility is determined, the next step is tissue typing, which is also called HLA (human leukocyte antigen) typing or antigen typing. There are more than 100 antigens on body cells, but six have been identified as the most important in organ transplantation.
These are antigens A, B and DR. As shown in Table 1 below, a kidney patient in need of a transplant has two potential living donors. Both Donor 1 and Donor 2 are a mismatch of three out of six antigens, so, according to traditional HLA compatibility, they are equally good matches for the recipient. In addition to being healthy, living donors must have blood types and tissues compatible with the recipient of the kidney.
The transplant team will perform tests to see if the blood and tissues are compatible (compatible with health) with the recipient of the kidney. If they are not, our living donor program can also inform you about the matched giving program. It is obvious that an increase in post-mortem organ donation rates would positively affect patients of all blood groups who were on the waiting list and not just for kidney transplantation. I hadn't met anyone in my life with kidney problems, or who needed an organ transplant, but I knew that only one kidney is needed to live.
When you need a kidney transplant, finding the most compatible living kidney donor can mean a more successful transplant. If you're healthy, donating a kidney won't increase your chances of getting sick or having major health problems.