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ANAEMIA : PERNICIOUS

What is Pernicious Anaemia ?

Pernicious anaemia received its name when the cause was not known, and there was no effective treatment available. It often caused the death of the affected patient. It can now be diagnosed and treated very easily, so the name « pernicious » is no longer very appropriate. Pernicious anaemia is due to a lack of vitamin B12. This is an essential vitamin, needed by all cells of the body in order to allow them to multiply. When the body is short of vitamin B12 , red blood cells are principally affected, since millions of red cells need be made every minute. The lack of red blood cells leads to anaemia. The common symptoms of anaemia are tiredness, shortness of breath and awareness of the heart beat (palpitations). Some of the other cells of the body which need to be replaced rapidly can also be affected, for example the lining of the mouth. This can cause soreness of mouth and tongue. As well as being needed for dividing cells, vitamin B12 is needed to keep nerves healthy. Shortage of vitamin B12 can therefore lead to nerve problems. These include tingling and numbness in fingers and toes, confusion and poor memory.

How does Pernicious Anaemia occur ?

All foods of animal origin, including milk and dairy produce, contain vitamin B12. But it has to combine with a substance produced by the stomach called intrinsic factor in order for it to be absorbed in the bowel. If a part of the stomach has been removed by operation, then there may be a shortage of intrinsic factor, and B12 cannot be absorbed normally. Another cause for the lack of intrinsic factor is that the body produces a protein called an antibody. Antibodies are substances which are normally produced against foreign proteins, for example in response to infection. However, they can sometimes be made against the body's own tissues. The antibody damages the cells which line the stomach, and cause pernicious anaemia. Shortage of vitamin B12 can also occur if diet is lacking in vitamin B12, for example in strict vegetarians, or if there is a disease affecting the part of the bowel where vitamin B12 is normally absorbed, such as coeliac disease. This has exactly the same effect as when the lack of vitamin B12 results from lack of intrinsic factor. However, the name pernicious anaemia is reserved for those cases where the problem is lack of intrinsic factor.

Why does Pernicious Anaemia occur ?

The tendency to develop pernicious anaemia is often inherited. It usually develops after the age of 40 and is commoner in women. There is also a link between pernicious anaemia and disorders of the thyroid gland. Thyroid problems are often caused by the person producing an antibody to his or her own thyroid tissue. Both types of disorder tend to occur in the same families and may occur in the same individual.

Treatment Involved for Pernicious Anaemia

Pernicious anaemia is treated by giving injections of vitamin B12. The B12 has to be given to you by injection because it cannot be properly absorbed if taken by mouth. Usually about six injections are given over 1 to 2 weeks and then one injection every 2 to 3 months for the rest of your life. It has to be given lifelong because there is no way of getting rid of the antibody that has been made against the stomach cells. This does not matter because the antibody does not have any other harmful effects. Because thyroid problems can occur with pernicious anaemia, the doctor will usually arrange for blood to be tested to see if the thyroid gland is working normally.

During Treatment for Pernicious Anaemia

There are no side-effects from vitamin B12 injections and indeed you may feel much better already after your first injection. Once started on vitamin B12 treatment, the anaemia will improve rapidly. Any symptoms of anaemia will also disappear as the number of red blood cells increases and the haemoglobin level returns to normal. However, symptoms due to nerve problems, like tingling in the fingers, may take much longer to improve. On treatment, there is a full and normal life expectancy.

After Treatment for Pernicious Anaemia

Pernicious anaemia will not recur provided that injections of vitamin B12 are being given regularly. Most doctors will want to check your blood count every year and also do a thyroid test from time to time.

If Pernicious Anaemia is Left Untreated

Anaemia would get steadily worse. You would be more likely to develop nerve problems. This may produce severe weakness and unsteadiness when walking. If these symptoms have been present for a long time, you might not recover completely even when treated with vitamin B12.

Effects on Family of Pernicious Anaemia

Most people notice a striking difference after the condition is treated. The tendency to pernicious anaemia and thyroid disease is often inherited. The doctor may therefore suggest that your brothers, sisters, parents or children are tested from time to time. Vitamin B12 injections must be continued for life.