Transplant Terms, Explained

Allograft

Organ transplanted from one person to another.

Antibody-mediated rejection (AMR)

When a transplant recipient’s immune system attacks their new kidney using specific proteins (called antibodies, or DSAs) that recognize it as coming from someone else.

Antigen

A molecule—often a protein—that can trigger an immune response from the body’s immune system.

Biopsy (kidney biopsy)

A procedure where a small sample of kidney tissue is taken and examined to check for signs of rejection or damage. It’s usually only done if lab results suggest something may be wrong, but can also be part of routine care.

Blood sugar (glucose)

The main type of sugar in our blood, which our bodies use for energy.

Caregiver / care partner

A family member or friend who supports a transplant recipient, for example, by helping with appointments or day-to-day tasks at home.

Complete blood count (CBC)

A blood test that measures different types of blood cells, including red blood cells, white blood cells, and platelets, to give a general picture of overall health.

Creatinine

A waste product that the kidneys filter out of the blood. A small amount in the blood is normal, but higher levels can be a sign that the kidneys are not working as well as they should.

Chronic kidney disease (CKD)

A condition where the kidneys are damaged for more than a few months. CKD has five stages based on GFR results (a test that shows how well the kidneys are filtering blood), with stage 1 being mild kidney disease and stage 5 being the most severe.

Delayed graft function (DGF)

When a transplanted kidney does not start working right away after surgery. It’s sometimes called “sleepy kidney” and may take time to begin working normally.

Dialysis

A treatment that uses a machine to remove extra fluid, electrolytes, and waste from the blood when the kidneys can no longer do this on their own.

Donor (living donor / deceased donor)

A person who provides a kidney for transplant. A living donor gives a kidney while they are alive, while a deceased donor gives a kidney after their death.

Donor-derived cell-free DNA (dd-cfDNA)

A blood test that measures small amounts of DNA from the donor kidney in a recipient’s bloodstream. When there is damage occurring to the transplant, such as during a rejection episode, cells are injured and will release DNA into the recipient’s blood (called donor-derived DNA). Higher levels than expected can be a sign that the kidney may be under stress or starting to experience signs and symptoms of rejection.

Donor-specific antibodies (DSAs)

Proteins the body may make against a transplanted kidney if it recognizes the kidney as coming from someone else. These antibodies can play a role in rejection.

eGFR (estimated glomerular filtration rate)

A measure of how well the kidneys are working. It shows how effectively the kidneys filter waste from the blood. Because directly measuring GFR is complex, doctors usually use an estimated value (eGFR) based on a blood test. Sometimes it may be explained as a percentage of kidney function for easier understanding.

Family Medical Leave Act (FMLA)

A U.S. law that allows eligible employees to take time off work for certain medical or family reasons without losing their job or health insurance. The leave is unpaid, but job and health coverage are protected during this time.

Foley catheter

A soft tube placed into the bladder to help drain urine (pee) after surgery.

Graft

A term for transplanted tissue, such as a donor kidney.

Graft survival

How long a kidney transplant lasts.

Human leukocyte antigens (HLA)

Proteins that the immune system may react to after a kidney transplant, which can cause it to reject the new kidney. HLAs help the body tell the difference between its own cells and something foreign.

Hypertension (high blood pressure)

Blood pressure that is higher than normal.

Hyperglycemia (high blood sugar)

When the level of sugar (glucose) in the blood is higher than the normal range.

Induction medicines

Medicines given during transplant surgery to suppress and/or regulate the immune system and reduce the risk of rejection.

Infection

Infections are common after transplant, especially soon after surgery and in the months or years that follow. Most can be treated with antibiotics. Chest and urinary infections are most common, and serious infections are less common.

Immunosuppressants (anti-rejection medicines)

Medicines that reduce the activity of the immune system to help prevent it from attacking a transplanted kidney. They are an important part of preventing rejection, but they can also increase the risk of infection because the immune system is less active.

Kidney transplant

A surgery where a healthy kidney from a living or recently deceased donor is placed into a person with advanced chronic kidney disease or end-stage kidney disease.

Matching

The process of finding out how closely a donor and recipient’s HLAs (proteins that the immune system recognizes) align. The more similar they are, the more likely the transplant is to be successful.

Maintenance medicines

Long-term medicines taken every day to prevent the immune system from attacking a transplanted kidney.

Organ offer

An offer of a donated organ to transplant candidates, sent through their transplant programs in a specific order based on the UNOS matching system and allocation policies.

Organ Procurement Organization (OPO)

A not-for-profit organization responsible for recovering organs from deceased donors for transplants in the U.S.

Organ Procurement Transplantation Network (OPTN)

A public-private network that connects all the organizations and professionals involved in organ donation and transplantation in the U.S.

Panel Reactive Antibody (PRA)

A measure of how many potential donors a person may have antibodies against. A higher PRA can make it harder to find a matching donor and may increase the risk of rejection.

Post-transplant diabetes mellitus (PTDM)

When a recipient develops diabetes (high blood sugar levels) after their transplant.

Primary non-function (PNF)

When a transplant kidney does not start working at all after surgery. It can happen, but is very rare.

Proteinuria

A higher-than-normal amount of protein in the urine. It can be a sign of kidney disease.

Recipient

A person who receives a donated kidney.

Rejection

When the body recognizes a transplanted kidney as coming from someone else and starts to attack it. Anti-rejection medicines help prevent this, but rejection can still happen in some cases.

Rejection medicines

Medicines used to treat rejection if the body begins to attack a transplanted kidney.

Renal dietitian

A registered dietitian who specializes in nutrition for people with kidney disease.

Support network

A group of people who provide emotional, social, or practical help to someone going through a transplant.

Supportive care

Also called palliative care. A type of medical care that focuses on comfort and support for people with serious illness, including relief from pain, symptoms, and stress. It is not only for people with a terminal illness.

Survivor’s guilt

Stress or guilt a person may feel after surviving something others did not. For transplant recipients, this can happen after receiving a kidney from a donor who has passed away or receiving a transplant while others don’t.

Tissue typing

A test used to identify a person’s antigens (proteins) to help match them with a donor kidney.

Transplant center

A hospital equipped to perform organ transplant surgeries. Transplant centers are part of the Organ Procurement and Transplantation Network (OPTN) and must meet strict requirements.

United Network for Organ Sharing (UNOS)

A nonprofit organization that operates the Organ Procurement and Transplantation Network (OPTN) under contract with the U.S. government.

Ureter

A narrow tube—part of your urinary system—that carries urine from the kidney to the bladder.

Ureteral stent

A thin, flexible tube placed into the ureter to help keep it open and support the flow of urine from the kidney to the bladder.

Urinalysis

A set of tests that examines urine to check for things like blood cells, protein, and other substances. It may be used as a routine test or to look for signs of infection, kidney or liver disease, diabetes, or other health conditions.

Urinary tract infection (UTI)

An infection of the urinary tract, usually through the urethra (the tube that carries urine out of the body).

Urine output

The amount of urine (pee) the body produces. This often increases after a successful kidney transplant. Any noticeable changes should be reported to the transplant team.

Waitlisted

Waitlisted/Listed active: When a person is on the kidney transplant waitlist and eligible to receive an organ offer.

Waitlisted/Listed Inactive/On Hold: When a person is on the waitlist but not currently eligible to receive an organ offer, often due to a temporary medical or logistical issue, such as illness or insurance changes.