In kidney transplantation, two important factors determine the compatibility between a donor and a recipient. The most important is blood type. If the blood type doesn't match, the body will reject a transplanted kidney immediately.

"Generally speaking, if you're a blood type O, you can donate to anybody," says Miguel Tan, M.D., transplant surgeon at Piedmont Transplant Institute. "If you're a blood type AB, you can receive from anybody. If you're A and B, there are some different issues there, but essentially, your blood type is the most important thing."

The second factor is antibodies. These proteins on your cells allow you to differentiate cells from non-cells. "And so, when a kidney is transplanted, it has its own set of proteins sitting on cells, and the body will recognize it as foreign," Dr. Tan says. "If it has pre-formed antibodies against the kidney, the body will reject it right away."

When people have a potential living donor, only about a third are compatible matches. But those patients still have hope thanks to a program called paired donation. "What we do is put them in a pool of donors," Dr. Tan says. "We have our own internal pool at Piedmont. There are regional pools. And, there is a national paired donation kidney network that involves about a hundred or so centers. The goal  is to identify other incompatible pairs so we can swap donors."

As an example, Dr. Tan uses a pair where the donor is blood type B, and the recipient is blood type A. "They can't donate to each other because of the blood type," he says. "What we do now is we go into our pool and identify another pair where the donor is blood type A and the recipient is blood type B, and we swap. So now, the B donor can  donate to the B recipient, and the A donor can donate to the A recipient." In the example, two people get transplants with living donors. If there are more than two pairs, even more transplants can be performed.

In paired donations, the donor and recipient go into the operating room at the same time. Once the recipient transplant team decides to begin the operation, the donor surgeon will remove the donor kidney. At that point, it's passed off to the recipient team, which will flush the kidney with a physiological solution to preserve it, put it on ice, walk it next door, and then sew it in.

"That's the big advantage," Dr. Tan adds. "There is no cold time. You don't have to put the kidney on ice, stick it in a box and transport it on an airline. All those things can prevent the kidney from working right away. With living donor kidneys, basically, within 20 minutes of removing the kidney, you're sewing it in. And because of that, almost 100% of these kidneys work within 24 hours."

• Two important factors determine compatibility in kidney transplantation – blood type and antibodies.
• Donors with blood type O can donate to anyone, and recipients with blood type AB can receive from anyone.
• In paired donations, incompatible pairs find their matches from a pool of donors and recipients.
• Piedmont's patients have the shortest wait times in Georgia for kidney transplants.
• More than half of all kidneys transplanted at Piedmont come from living donors.

To learn more about living kidney donation, visit the Piedmont Transplant Institute.

Need to make an appointment with a Piedmont physician? Save time, book online.