Matching Donors and Candidates
Carefully matching donors with transplant candidates is the key to a successful kidney transplant. There are four possibilities:
Paired donation or paired exchange
A paired exchange donation consists of two kidney donor/recipient pairs who are not compatible. The two recipients trade donors so that each recipient can receive a compatible kidney. Once the evaluations of all donors and recipients are completed, the two kidney transplant operations are scheduled to occur simultaneously. In some cases, this type of exchange has involved multiple living kidney donor/transplant candidate pairs.
Kidney donor waiting list exchange
If a paired exchange cannot be found, living donors in certain areas of the country may be eligible for living kidney donor list exchange. In this type of exchange, a kidney donor who is not compatible with their intended recipient offers to donate to a stranger on the waiting list. In return, the intended recipient advances on the waiting list for a deceased donor kidney. This type of living donation is also referred to as list-paired exchange and living donor/deceased exchange.
Blood type incompatible donation
This type of donation allows candidates to receive a kidney from a living donor who has an incompatible blood type. To prevent immediate rejection of the kidney, recipients undergo plasmapheresis and IVIG treatments before and after the transplant to remove harmful antibodies from the blood, as well as the possible removal of the spleen at the time of transplant.
Positive crossmatch donation
Positive crossmatch donation involves a living donor and a transplant candidate who are incompatible because antibodies (a protein substance) in the candidate will immediately react against the donor’s cells, causing loss of the transplant. Specialized medical treatment is provided to the candidate to prevent rejection. In a process similar to the process used for blood type incompatible living-donor kidney transplants, treating patients with plasmapheresis also greatly reduces the chance of organ rejection in patients with elevated antibody levels. Previously, these elevated antibody levels made tissue rejection almost certain. Positive crossmatch live donor kidney transplants are usually only performed if no other live donors (with a negative crossmatch) exist.