Living versus deceased donor kidneys and graft survival
Graft survival (the time a transplanted kidney keeps working) is generally shorter with a deceased donor (someone who has died) than with a living donor.
Remember
On average a living donor kidney lasts about 20 to 25 years and a deceased donor kidney about 15 to 20 years, so the deceased donor kidney has the shortest average graft survival of the standard donor sources. Even so, a deceased donor kidney is still a worthwhile treatment.
A transplanted kidney comes from one of three main sources: a living related donor (a relative), a living unrelated donor (for example a partner or friend) or a deceased donor (someone who has died, with the kidney removed after death).
Graft survival, meaning how long the transplanted kidney keeps working, differs by donor source. NHS Blood and Transplant gives averages of 20 to 25 years for a living donor kidney and 15 to 20 years for a deceased donor kidney.
Several things explain the gap. A living donation can be planned in advance and the donor can be assessed thoroughly first. A deceased donor kidney is kept cold until it is implanted, so it spends longer in ischaemia, a shortage of blood and oxygen getting to the tissue. The deceased donor's health is also harder to check, and the kidney is slower to start working.
A person's tissue type means the marker proteins on their cells, and the immune system uses these markers to recognise a transplant as coming from a different person. The main markers are the human leukocyte antigens (HLA), which differ from person to person. Because HLA genes come from the parents, a relative is more likely than a stranger to share the HLA types of the recipient (the person getting the kidney), and closer tissue matching improves transplant outcomes. Closer tissue matching is one reason living related donors are taught as giving the best results, along with planned surgery.
Being related is not what makes the difference to graft survival: the key contrast is living versus deceased donation. Large European data found similar graft survival for living related and living unrelated donors, and partners and friends do well, with results nearer to related donors than to deceased donors.
Key facts
- Living donor kidney
- lasts about 20 to 25 years on average.
- Deceased donor kidney
- lasts about 15 to 20 years on average, the shortest of the standard donor sources.
- Why deceased kidneys do worse
- a longer time without a blood supply, a donor whose health is harder to check, and slower early function.
- Deceased donor transplant window
- a kidney tolerates time outside the body poorly, and kidneys stored on ice function best if transplanted within about 18 hours.
- Taught as the best source
- living related donors, helped by closer tissue matching and planned surgery.
- Unrelated living donors
- partners and friends do well, with results nearer to related donors than to deceased donors.
- Averages only
- outcomes vary between individuals, so a single kidney may do better or worse.
Exam traps
- Deceased donors are the commonest source of kidneys in the UK, but that does not make their kidneys last as long as living donor kidneys: on average they last 15 to 20 years, against 20 to 25 years.
- A partner or friend is often a poorer tissue match than a relative, but that does not put their kidney below a deceased donor kidney: in published results it fares clearly better than deceased donor kidneys, and its results come close to those of related donors.
- A living related donor kidney does not have the lowest graft survival: living donor kidneys generally outperform deceased donor kidneys, and large European data found similar graft survival for living related and living unrelated donors.
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