Here are some of the terms you might encounter in discussions of living donor transplants.

Allograft. Organ or tissue transplant between individuals of the same species.

Antibody. A protein substance developed by the body's immune system in response to a foreign substance.

Antigen. A molecule or foreign substance, such as a transplanted organ, that triggers an immune response. This response may be the production of antibodies, which try to destroy the antigen.

Anti-Rejection Drugs (immunosuppressive drugs). Drugs that are taken to artifically suppress of the immune response of the body so it will not reject a transplanted organ or tissue.

Arteriogram. An X-ray of an artery after a dye has been injected.

Cadaveric Donor. A person who has been declared "brain dead," or whose heart has stopped beating and will not restart on its own, whose family has offered one or more organs to be used for transplantation.

Chronic Rejection. Slow failure of the transplanted organ.

Crossmatch. A blood test done before the transplant to see if the donor organ is compatible with the potential recipient. If the crossmatch is ‘positive,' then the donor and patient are incompatible. If the crossmatch is ‘negative,' then the transplant may proceed. Crossmatching is performed for kidney and pancreas transplants.

Delayed Graft Function. A condition in which the transplanted organ does not start functioning right after the transplant. Many cadaveric kidneys have a delay before they "wake up," and can take as long as three weeks to function well. A kidney recipient sometimes needs dialysis until the transplanted kidney starts to work.

Graft. A transplanted organ.

Graft Survival. The functioning of a transplanted organs (graft). A common measure of the success of transplants is the graft survival rate. The other measure is the patient survival rate.

Hepatic. Having to do with, or referring to, the liver.

Human Leukocyte Antigens (HLA). Molecule found on cells in the body that characterize each person as unique. These antigens are inherited from your parents. In donor-recipient matching, three major HLA tissue types of the donor and recipient are important in determining whether the transplant will be accepted or rejected. This testing is performed for kidney and pancreas transplants.

Match. The compatibility between the donor and the recipient. The more closely they match, the greater the chance that the transplant will be successful.

Nephrectomy. Surgical removal of the kidney.

Organ. A part of the body made up of tissues and cells that enable it to perform a particular function. Transplantable organs are the heart, liver, lungs, kidneys, pancreas, and intestines.

Organ Donation. To give an organ, such as your kidney, to someone in need of that organ; or to decide that in the event of your death, you want to donate your organs to people in need of them.

Organ Procurement and Transplantation Network (OPTN). A national network operated by the United Network on Organ Sharing (UNOS) under contract to the U.S. Department of Health and Human Services. The OPTN maintains the computerized lists of patients waiting for different types of organs and a 24 hour-a-day computerized organ placement center to match cadaveric donor organs to recipients in a fair and efficient manner.

Organ Procurement Organization (OPO). OPOs are responsible for the identification of potential cadaveric organ donors, and the retrieval, preservation and transportation of cadaveric organs for transplantation. Currently, there are 69 OPOs around the country.

Rejection. Rejection occurs when the body attacks and tries to destroy a transplanted organ because it sees the organ as a foreign object and produces antibodies to destroy it.

Renal. Having to do with, or referring to, the kidneys.

Retransplantation. Some patients, as a result of rejection or failure of a transplanted organ, need to receive another transplant.

Scientific Registry of Transplant Recipients (SRTR). The SRTR compiles and makes available nformation on all recipients of kidney, heart, liver, heart-lung, lung, pancreas, kidney-pancreas and intestine transplants since October 1, 1987. The SRTR is operated by University Renal Research and Educational Association under contract to the U.S. Department of Health and Human Services. Follow-up data on every transplant are used to track transplant center performance, transplant success rates and medical issues impacting transplant recipients.

Sensitized. When potential transplant recipients have antibodies in their blood, usually because of pregnancy, blood transfusions or previous rejection of an organ transplant, they are said to be sensitized. Sensitization is measured by panel reactive antibody (PRA). Highly sensitized patients are less likely to match with a suitable donor and more likely to reject an organ.

Survival Rates. Survival rates indicate the percentage of patients that are alive, or grafts (organs) that are still functioning, at certain benchmarks (ie, one-year, three-years, five-years) after a transplant.

Tissue Typing. A blood test that enables identification of antigens individual to each person, allowing doctors to determine how in advance how closely the tissues of the donor match those of the recipient. This test is performed on all potential kidney donors and recipients.

Transplant. To transfer a healthy organ from one person's body to the body of a person in need of that organ.

If you encounter any words or phrases that you think should be added to this list, please send them to us at editor@transplantweek.org.

All information provided in this site is offered for educational purposes only, and it is not intended nor implied to be a substitute for professional medical advice. Always consult your own physician or healthcare provider with any questions you may have regarding a medical condition.