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Kidney transplants

Kidney transplantation is an alternative method for treating kidney failure and can save a patient's life. This procedure involves implanting a kidney from an organ donor into the patient’s body to replace the damaged kidney. This is better than using a restrictive dialysis machine, as the recipient can lead a normal life afterwards.

As with all cells, the donor kidney cells will have protein antigens on their surface. Antigens are unique to each of us (with the exception of identical twins), and allow our body to identify our own cells from those of potential pathogens.

Differences in the antigens of the donor kidney cells and those of the patient receiving the transplant would mean that the patient's immune system would quickly form antibodies against the kidney cell antigens, and would ultimately destroy the kidney. This is known as organ rejection. This is potentially very harmful for the patient.

Precautions against rejection

Two precautions can be taken to reduce organ rejection:

1. Tissue typing - a kidney is given to patients who have antigens that are very similar to the antigens of the donor kidney. This can lead to long waits for transplants while compatible donors become available - during which time patients must undergo dialysis, and in some cases they will die before a match is found.
2. Immuno-suppressant drugs – these drugs must be taken by transplant patients for the rest of their lives. They suppress the immune system, greatly reducing the immune response against the donor kidney. The negative effect of this is that it also suppresses the immune response against pathogens which enter the body, increasing the risk of infections.

Even with these two precautions, most donor kidneys will only survive for an average period of 8-9 years before the patient will require a further transplant or a return to dialysis.

Transplants versus dialysis

The table below shows some of the pros and cons for both kidney dialysis and kidney transplants