How the Transplant System Works: Matching Donors and Recipients

Under the Organ Procurement and Transplantation Network (OPTN) contract with the U.S. Department of Health and Human Services' Health Services and Resources Administration, UNOS maintains a centralized computer network linking all organ procurement organizations and transplant centers. This computer network is accessible 24 hours a day, seven days a week, with organ placement specialists in the UNOS Organ Center always available to answer questions.

A person who may benefit from a transplant is referred by his or her doctor to a transplant center, which evaluates the patient. The transplant center runs a number of tests and considers the patient's mental and physical health, as well as his or her social support system. If the center decides to accept this person as a transplant candidate, they will add his or her medical profile to the national patient waiting list for organ transplant. The candidate is not placed on a ranked list at that time. Rather, his or her information is kept in a constantly updated, computerized database. When a deceased organ donor is identified, a transplant coordinator from an organ procurement organization accesses the UNOS computer. Each patient in the database is matched by the computer against the donor characteristics. The computer then generates a ranked list of candidates for each available organ in ranked order according to OPTN organ allocation policies.

The match for each donor organ will be different and unique to the circumstances of the donor and the patients waiting. Factors affecting ranking may include tissue match, blood type, length of time on the waiting list, immune status and the distance between the potential recipient and the donor. For heart, liver, lung and intestines, the potential recipient's degree of medical urgency is also considered. The organ is offered to the transplant team for the first person on the match list. Often, the top patient will not get the organ for one of several reasons. When a patient is selected, he or she must be available, healthy enough to undergo major surgery, and willing to be transplanted immediately. Also, a laboratory test to measure compatibility between the donor and recipient may be necessary. For example, patients with high antibody levels often prove incompatible to the donor organ and cannot receive the organ because the patient's immune system would reject it.

Once a patient is selected and contacted and all testing is complete, surgery is scheduled and the transplant takes place.

Related Internet Sites

Transplant Living

U.S. Department of Health and Human Services Web site for Organ Donation

The Organ Procurement and Transplantation Network
Operated by UNOS under contract with HRSA.