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You Can Donate a Kidney Even When You’re Not a Perfect Match

National Kidney Registry

It’s one of the most frustrating and discouraging situations in kidney donation: A donor is medically healthy and eager to donate a kidney to someone facing kidney failure, but testing determines that the donor is not a match with the recipient.

When faced with this scenario, kidney patients used to have to keep looking for a matching donor. No more.

To ensure the best possible match between living donor kidneys and kidney transplant recipients, the National Kidney Registry (NKR) uses a system called the Voucher Program. Here’s how it works:

  1. A donor (Donor A) wants to donate a kidney to a specific recipient (Recipient A)—a friend, family member, etc.
  2. Donor A undergoes the required testing and discovers that they are not able to donate a kidney directly to Recipient A because the two are not a match due to incompatibility of blood type, tissue type, crossmatching or some other medical factor.
  3. Donor A still wants to donate their kidney if that means Recipient A will be able to get a transplant, so Donor A enters the Voucher Program through the NKR.
  4. After being activtated in the NKR system, Donor A donates their kidney at an NKR center of their choice, at a time that is convenient to them.
  5. Donor A’s donated kidney goes to a well-matched recipient (Recipient B), and the donation generates a voucher for a future transplant with a living donor kidney, which is given to Recipient A.
  6. When Recipient A is ready for transplant surgery, they activate their voucher to be prioritized for a living donor transplant through the NKR.
  7. The NKR looks at its large pool of donors and identifies a donor (Donor B) that is the best match for Recipient A. After Donor B undergoes donation surgery, the donated kidney is transplanted into Recipient A.

All this is made possible through the latest technology in kidney matching by the National Kidney Registry.

New and Improved Kidney Matching Technology

Traditionally, tissue typing for kidney donor-recipient matching was measured using antigen compatibility, with a match score from zero out of six (the worst match, indicating a high probability that the donated kidney would be rejected by the recipient) to six out of six (a perfect match, usually only occurring with identical twins).

Now there is a better, more accurate matching technology based on eplets, which are components found inside antigens. Matching based on eplets is a more precise measurement of donor-recipient compatibility and makes it possible for the NKR to find the best donor for each recipient.

Because the NKR is able to find the best match for each recipient from among its donor pool, which is the largest in the world, there is no need for a donor to be a match for the person they want to donate a kidney to. In fact, in most cases, even if a donor is a good match for their intended recipient, they can find an even better match by entering the Voucher Program.

It’s important to find the best match possible, because the better the match, the better the chance the transplant will be successful and the longer the transplanted kidney is likely to last. In addition, with a better match, the transplant recipient may be able to take lower dosages of immunosuppression medications.

Donating a kidney to someone is an amazing gift, and one that should not be limited by technical issues like donor-recipient compatibility. With the Voucher Program, anyone who is medically able and willing to donate a kidney may do so and ensure that their intended recipient gets the best possible living donor kidney for their life-saving transplant. For more information, visit https://www.kidneyregistry.org/for-donors/voucher-program/.