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Homeostasis: 8. Kidney problems, transplants and dialysis - their advantages and disadvantages

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There are various sections to work through.

Sub-index of biology notes on homeostasis: Kidney structure and function - osmoregulation

(8) Kidney transplants and problems - dialysis or transplant? - advantages and disadvantages

Why can you have kidney problems?

Medical problems with your kidney function can arise from several causes e.g. genetic factor, high blood pressure (hypertension damages organs), obesity and lack of exercise, diabetes, excessive alcohol consumption (not just liver damage), smoking (not just lung damage), stress or, though very rarely, from an infection that spreads to the kidneys.


Kidney transplants

In kidney transplants a diseased kidney is replaced with a healthy one from a donor.

You can function well, with care, with only one kidney.

This the case if e.g. a living family member donates one of their kidneys to another family member.

This situation gives the best chance of tissue matching and minimises the danger of rejection by the kidney recipient.


Source of kidney organs

Kidney transplants are one of the most common organ transplant operations done in our modern health service (eg the NHS of the UK).

The only cure for serious kidney disease is to have a kidney transplant, hopefully from a suitable matching donor.

The donor can be a relative donating one of their kidney's or a fatal accident victim e.g. somebody who has died suddenly.

The person who has died must be on the donor organ register or carrying a donor card (providing relatives agree to the organ donation) - this is the current situation in UK Law - but it may change.

Any donated organs must be stored in cold conditions, for as shorter time as possible, to minimise tissue deterioration.

Since we have two kidneys, one can be transplanted from a living person to the kidney failure recipient, but with some residual risk to the donor.

In the surgical operation the recipient's abdomen is opened below the navel and the new kidney connected to an artery and vein so it can function with full blood supply.

The kidney is further connected to the bladder for urine collection.

The kidney should, at least partially, work immediately, but it may take several weeks to be fully working.

It is a complex operation taking 2-3 hours.


Problems with kidney transplants

However, the donor kidney may be rejected by the immune system unless precautions are taken.

The immune system treats the transplanted tissue as 'foreign' and its cells are attacked by antibodies.

Transplant rejection

1. The white blood cells of the organ recipient sense the antigens of the cells of the transplanted kidney are foreign and not part of the body of the transplant patient.

2. The recipient's white blood cells respond to the perceived 'foreign' antigens by producing matching antibodies

3. The antibodies attack the 'donated' kidney cells and destroy them and so the kidney transplant is rejected.

Therefore, precautions must therefore be taken to minimise the risk of kidney rejection.

(i) You can test how well the donor's kidney tissue type closely matches the recipient's kidney tissue.

The tissue-type is based on the cell's antigens.

The more similar the antigens of the donor and recipient's kidney cells, the greater the chance of organ acceptance i.e. the less chance patient's white blood cells identify the donor's antigens as 'foreign' and produce antibodies to attack the donated organ.

(ii) The patient needs to be treating with immunosuppressant drugs to prevent organ rejection, but it may still happen.

These drugs are designed to suppress the patient's immune system to stop it attacking the cells of the transplanted kidney tissue.

Unfortunately, these drugs reduce the body's white cells ability to produce antibodies, so they won't attack the kidney cells of the donated organ.

So, these drugs make the patient more susceptible disease that would normally be counteracted by their immune system - there is a risk of both infection and cancer.

There are also problems with availability of kidney organs, e.g. a long waiting list and the cheaper dialysis is often used as an interim treatment.

Antigens are proteins on the surface of cells., and a recipient’s antibodies (from white blood cells of the immune system) may attack the antigens on the donor organ as they do not recognise them as part of the recipient’s body and so the transplanted kidney is rejected.

So, summarising - in order to minimise rejection of the transplanted kidney:

A donor kidney with a ‘tissue-type’ similar to that of the recipient is used - which is where a generous relative can mean the difference between life and death.

The recipient is treated with drugs that suppress their immune system response to reject the kidney transplant.

Tests for blood grouping and compatibility tables are part of the procedure to give the transplant the best chance of not being rejected.


Dialysis or transplant? Advantages and Disadvantages - the 'Pros and Cons'

In the long run, transplants are cheaper than dialysis, but there is a shortage of donated kidney organs for transplant operations.

Organ donation involves ethical issues for us and other animals.

Some people may think it is wrong to use parts of other peoples bodies.

Relatives may override the wishes of the deceased even though they may have carried a donor card.

Some poor people are prepared to sell one of their kidneys for money - should this be allowed to increase the availability of organs?

Should we transplant organs from animals? but there are concerns over cross-species infections.

What animal rights involving breeding animals specifically for a particular organ like the kidney?

Will biotechnology enable us to grow complex organs like the kidney in the future?

There is a long waiting list for surgery, but at least dialysis keeps patients with kidney failure alive, and increases the chance of undergoing kidney transplant surgery!

For elderly patients, dialysis can reduce life expectancy due to complications - maybe due to other underlying health problems.

Dialysis patients can suffer from sudden falls in blood pressure, and they must always be on the lookout for signs of infection.

Without a kidney transplant, dialysis patients must continue with the treatment for the rest of heir lives.

A kidney transplant gives the patient a much better freedom of lifestyle - greater independence and general quality of life - no need to go to a medical centre for dialysis or receive dialysis in the home.

Patients with other underlying health issues like heart disease may not be able to withstand the stress of transplant surgery, so dialysis is the only option to stay alive.

Dialysis patients must take great care in lifestyle e.g. no smoking, minimum alcohol and avoid excess weight.

Many of the points raised here apply to the advantages and disadvantages of other transplant procedures.

Keywords, phrases and learning objectives for this part on kidney transplants and dialysis

Kidney problems can arise from several causes e.g. genetic, high blood pressure, diabetes or from an infection.

After kidney failure transplants versus convenient dialysis must be considered and lack of kidney donors is a constant problem - the donated kidney must be matched with the recipient patient, otherwise rejection is highly likely.

Know there are problems with having a kidney transplant e.g. rejection of donated kidney by the recipient's immune system and why patients must adjust their lifestyle e.g. preferably no alcohol, no smoking and possibly restrictions on diet - avoid being overweight..

Be able to evaluate the advantages and disadvantages of treating kidney failure by dialysis or kidney transplant.



INDEX of biology notes on homeostasis: Kidney structure and function - osmoregulation


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