The human body possesses a powerful natural defence system that can identify and take action against any foreign body that is introduced into it. This reaction could be in response to a germ, a blood transfusion or to an organ, in the case of transplantation. Although a donor organ is carefully matched to the transplant patient by tissue typing and cross matching, the body will still recognise it as foreign and attempt to reject it. For this reason, transplant patients are given immunosuppressive medicines to reduce the response of the immune system and prevent rejection. Even so, most transplant patients experience mild episodes of rejection at some stage.
There are three types of rejection that may result from the body’s response to donor organs: acute, chronic and hyperacute.
Acute rejection episodes occur mostly in the early months after a transplant. They are periodic. They are most commonly seen in the first 7 - 14 days after transplantation and less frequently after the first three months. For this reason outpatient monitoring is very important after discharge from hospital following a transplant. Patients are routinely admitted to hospital during rejection episodes for monitoring and treatment. If you experience any of the symptoms below, you should inform your transplant unit as soon as possible.
Blood tests may reveal that the creatinine and urea levels are raised, as the kidney is not working as well. It may also be the case that blood pressure will be increased. A biopsy of the transplanted kidney may be taken to confirm the diagnosis of acute rejection, and to establish how severe this rejection is.
Normally, the first line of treatment for acute rejection is a short three-day course of steroids. This may be repeated if necessary, or other more powerful immunosuppressive drugs may be used.
Chronic rejection is the term used to describe slow, progressive loss of function in a transplanted kidney. Transplant research shows that transplanted kidneys steadily lose function over the long term, and this factor has not changed significantly over the last 10 years. How quickly a particular organ deteriorates is affected by factors such as how well an organ is matched to the recipient and how much function a kidney has when it is transplanted.
Chronic rejection will normally be detected by a steady decline in renal function, with changes seen in the creatinine levels and an increase in protein loss into the urine. Sometimes a biopsy may be taken of the transplanted kidney. It may take several years for the kidney function to decline to a level where it would be necessary to return to dialysis or plan for another transplant.
Chronic rejection may be accelerated by events that are likely to cause damage to the kidney for example:
The effect of immunosuppressive drugs
The immunosuppressive medications prescribed after transplantation are essential to prevent acute rejection occurring, but they can also damage the kidney. To maximise the function of the transplanted kidney it might be necessary to adjust the amounts of the drugs prescribed, or to change to a different immunosuppressive drug.
Treating chronic rejection
If chronic rejection is occurring, the treatment is aimed at maintaining the kidney for as long as. Medication may be altered to control blood pressure and slow kidney deterioration such as changes to the immunosuppressive drug treatment.
A patient with chronic rejection needs to be prepared for an eventual return to dialysis and another possible transplant with the implications that has for the way they live.
Due to improvements in matching organs to recipients, hyperacute rejection is now very, very rare. Hyperacute rejection occurs immediately when the recipient’s blood comes into contact with the donated organ and after the transplant and would probably be seen by the surgeons whilst still in theatre. The transplanted kidney becomes swollen and the area tender. The patient develops a temperature. The kidney’s function deteriorates very rapidly failing within 24 hours or it does not function at all and may require removal.