The three main advantages for both donor and recipient are: faster access to a transplant, shorter dialysis time and a kidney that, in principle, functions better and longer.
It is often several years before a kidney from a deceased donor can be transplanted. For some patients, because of the rarity of their blood group or the presence of antibodies (due to transfusions, pregnancies or previous transplants), a transplant from a living donor may be the only possibility within a reasonable timeframe.
Dialysis is a cumbersome treatment. Patients are weakened and often have to reduce or cease all professional activity. Recourse to a living donor can shorten this period of dialysis, or even eliminate it altogether. When a patient suffering from end-stage renal failure receives a transplant before starting dialysis, this is known as a pre-emptive transplant.
When the donor is a perfectly matched sibling (one chance in four), this excellent compatibility means that anti-rejection treatment can be reduced, and even better results can be expected in the very long term. As a result, the transplanted kidney very quickly regains its purification capacity, and it is rare for dialysis sessions to be necessary immediately after the transplant, just long enough for the graft to function properly again. Around 3/4 of living kidney transplants are still functional 10 years after transplantation.