Transplant Glossary
Simple explanations of the words and scores you'll hear from your transplant team.
- Acute rejectionSurgery & Recovery
- When the immune system attacks a new organ, usually in the first months after transplant. It is common and often treatable with medicine if caught early.
- BilirubinLab Tests
- A liver blood test and part of the MELD score. High levels can cause yellow skin or eyes (jaundice).
- BiopsyLab Tests
- A small tissue sample taken from the transplanted organ to check for rejection or other problems.
- Chronic rejectionSurgery & Recovery
- Slow, long-term damage to a transplanted organ by the immune system over months or years. Taking medicines exactly as prescribed helps prevent it.
- CMV (Cytomegalovirus)Lab Tests
- A common virus that can cause illness in transplant patients. Your team may test for it and give preventive medicine.
- Cold ischemia timeSurgery & Recovery
- How long a donor organ is kept cold without blood flow between removal from the donor and placement in the recipient. Shorter times usually mean better results.
- ConditioningSurgery & Recovery
- Chemotherapy and/or radiation given before a bone marrow transplant to make room for new cells and suppress the immune system.
- cPRA (Calculated Panel Reactive Antibody)Matching & Immunology
- A percentage estimating how many donors you would likely reject because of antibodies in your blood. A higher cPRA can mean a longer wait, but may also give extra priority.
- CreatinineLab Tests
- A blood test showing how well the kidneys filter waste. A rising number after kidney transplant can be an early warning sign.
- CrossmatchMatching & Immunology
- A lab test that mixes your blood with donor cells to check whether your body already has antibodies that would attack that donor's organ. A negative crossmatch is good.
- CyclosporineMedications
- An older anti-rejection medicine still used for some patients. Blood levels are monitored closely.
- Donor-specific antibodies (DSA)Matching & Immunology
- Antibodies in your blood that target a specific donor's tissue type. Doctors watch for these before and after transplant.
- eGFRLab Tests
- Estimated glomerular filtration rate: a number calculated from creatinine that shows kidney function. Kidney waitlist time can start counting when eGFR is 20 or less.
- EngraftmentSurgery & Recovery
- In bone marrow transplant, the point when donor stem cells start making new blood cells, usually 2–4 weeks after transplant.
- EPTS (Estimated Post-Transplant Survival)Scoring & Allocation
- A kidney score from 0–100% based on age, diabetes, dialysis time, and prior transplant. Patients with low scores may get priority for longer-lasting kidneys.
- GraftSurgery & Recovery
- The transplanted organ or tissue. 'Graft function' means how well the new organ is working.
- Graft-versus-host disease (GVHD)Surgery & Recovery
- A complication of bone marrow or stem cell transplant where donor immune cells attack the patient's body, such as skin, gut, or liver. It can be mild or serious and is treated with medicines.
- Heart Status (1–6)Scoring & Allocation
- The US heart allocation system ranks patients from Status 1 (most urgent, such as on certain heart pumps) to Status 6 (stable). Higher urgency gets offers first.
- HLA (Human Leukocyte Antigen) typingMatching & Immunology
- A blood or cheek-swab test that identifies your tissue type. Closer HLA matches between donor and recipient usually lower the risk of rejection, especially for bone marrow.
- ImmunosuppressantsMedications
- Anti-rejection medicines that calm the immune system so it does not attack the new organ. Most organ recipients take them for life.
- Inactive status (Status 7)Scoring & Allocation
- You stay on the list and may keep building wait time, but will not get organ offers until you are made active again — for example during an infection.
- Induction therapyMedications
- Strong anti-rejection medicine given around the time of surgery to lower early rejection risk.
- INRLab Tests
- A blood clotting test. In liver disease it shows how well the liver makes clotting proteins and is part of the MELD score.
- KDPI (Kidney Donor Profile Index)Scoring & Allocation
- A score from 0–100% describing how long a donor kidney is expected to last compared with others. Lower KDPI kidneys are expected to last longer.
- LAS / CAS (Lung Allocation / Composite Allocation Score)Scoring & Allocation
- Scores used to prioritize lung transplant candidates based on medical urgency, expected benefit, and other factors. The US moved from LAS to the Composite Allocation Score in 2023.
- Living donorSurgery & Recovery
- A healthy person who donates a kidney or part of a liver while alive. Living donation can shorten the wait and often leads to excellent results.
- Maintenance immunosuppressionMedications
- The daily anti-rejection medicines taken long-term after transplant, often a combination such as tacrolimus, mycophenolate, and a steroid.
- MELD / MELD 3.0Scoring & Allocation
- Model for End-Stage Liver Disease: a score from about 6 to 40 calculated from blood tests. Higher scores mean more urgent need for a liver. MELD 3.0 is the current US version.
- Mycophenolate (CellCept, Myfortic)Medications
- A common anti-rejection medicine. It can upset the stomach and lower blood counts, so labs are checked regularly.
- OPO (Organ Procurement Organization)Scoring & Allocation
- A nonprofit that coordinates organ donation in a region, working with hospitals and donor families.
- Opportunistic infectionSurgery & Recovery
- An infection that takes advantage of a weakened immune system, such as CMV. Preventive medicines are often given after transplant.
- OPTN / UNOSScoring & Allocation
- The Organ Procurement and Transplantation Network runs the national US waitlist and matching system. UNOS has operated it under federal contract.
- PELDScoring & Allocation
- Pediatric End-Stage Liver Disease score, the version of MELD used for children under 12.
- Prednisone (steroids)Medications
- A steroid often used with other anti-rejection medicines. Side effects can include higher blood sugar, mood changes, and weight gain.
- Tacrolimus (Prograf, Envarsus)Medications
- A widely used anti-rejection medicine. Blood levels are checked often, and it should be taken at the same times each day. Avoid grapefruit unless your team says otherwise.
- Tacrolimus trough levelLab Tests
- A blood test taken right before your next dose to measure how much tacrolimus is in your body. Your team adjusts your dose based on it.
This website provides general educational information only and is not a substitute for professional medical advice. Always consult a qualified healthcare provider for decisions about your care.