When you need a kidney transplant, finding the best match can mean a more successful transplant. The better the match between the donor and recipient, the longer the transplanted kidney can last. How Does the NKR Find the Best Donor-Recipient Match for Kidney Transplants? Traditionally, kidney transplant matches were measured by an HLA match score from zero to six, with six being the best. HLA scores are generally based on A, B and DR antigens.
Except in cases of identical twins and some siblings, it is rare to get a six-antigen match between two people, especially if they are unrelated. Kidneys are very successfully transplanted between two people with no matching antigens. A person can make antibodies against another person’s HLA antigens.
The six antigens which have been identified as important for transplant are inherited from our parents, half from each. This makes a sibling the best possible chance for a perfect match, not a child, but a child is better than a stranger. A perfect match with an unrelated donor carries odds of one in 100,000, or a probability of .00001.
Living donor programs allow a relative or a compatible unrelated donor (such as a spouse or friend) to donate a kidney. Siblings have a 25% chance of being an "exact match" for a living donor and a 50% chance of being a "half-match." Donor compatibility is established through blood tests that look for matching blood types and antigens.
It is believed that the better the HLA match, the more successful the transplant will be over a longer period of time. Because of the way chromosomes/DNA are inherited or passed down in a family, a parent and child would have at least a 50 percent chance of matching, siblings could have a zero to 100 percent match, and unrelated donors would be less likely to match at all.
The chance of a perfect or six-antigen match between two unrelated people is about one in 100,000. Many times in kidney transplants there are half matches or less and the transplants are still successful.
Then, what are the chances of being a kidney donor match? Siblings have a 25% chance of being an "exact match" for a living donor and a 50% chance of being a "half-match." Donor compatibility is established through blood tests that look for matching blood types and antigens. The overall health of the potential donor is also of critical importance.
The United States is divided into 11 regions and 58 local Organ Procurement Organizations (OPO)s, which are areas used to find matches for transplant. For example, if a kidney becomes available, UNOS will first try to find a match in the OPO where the kidney is being donated. If no match is found there, UNOS will search within the larger region.