To help you better understand the Kidney Paired Donation process, we have compiled a list of terms that you will likely hear while participating in KPD.
ABO Incompatible: Another term for blood type incompatibility. Donors can only donate an organ if they are blood type compatible with the recipient, unless the recipient undergoes special treatments to attempt to overcome the incompatibility.
Antibodies: Proteins that the immune system produces in response to foreign cells encountered through blood transfusions, prior transplants, and/or pregnancy. Antibodies can increase the risk of rejection and/or graft loss after transplant.
Compatible Intended Living Donor: A person who wants to serve as a kidney donor for a specific recipient, and is compatible in the traditional sense (blood type and crossmatch compatible), but may want to participate in a Kidney Paired Donation program in order to find a better age or genetic match.
Compatible Intended Recipient: A transplant candidate who has a willing, compatible donor (compatible intended living donor), but who may want to participate in a kidney paired donation program in order to find a better age or genetic match.
Crossmatch: A test where a potential donor's and transplant candidate's blood are mixed together to see if there is a reaction. If there is a reaction—called a positive crossmatch—it means the transplant candidate has antibodies against the donor, which increases the risk of immune system reactivity against a transplanted organ.
HLA Antigens: Proteins present on the surface of our cells that allow our immune system to recognize foreign cells—such as cells of a transplanted organ—that enter the body. When exposed to foreign antigens of other people through blood transfusions, prior transplants, and/or pregnancy, the immune system develops antibodies against HLA antigens.
Incompatible Intended Living Donor: A person who wants to serve as a kidney donor for a specific recipient, but is blood type or crossmatch incompatible.
Incompatible Intended Recipient: A transplant candidate that has a willing but incompatible living kidney donor (an incompatible intended living donor).
Matched Living Donor: A person who entered a kidney paired donation program as a potential donor and has been matched with a compatible recipient.
Matched Recipient: A transplant candidate who entered a kidney paired donation program and has been matched with a compatible donor.
Transplant Candidate: A person who has kidney failure and needs a kidney transplant.
Transplant Chain: A set of transplants generated by software that matches incompatible donor and recipient pairs in a kidney paired donation program (KPD) with other incompatible pairs. Introduction of an altruistic donor (a donor with no intended recipient) into these KPD programs can cause chains to become perpetual, since an extra donor will be "left over" to start another transplant chain in the future.