Monday, 30 November, 1998, 11:01 GMT
Multiple sclerosis is a degenerative disease of the central nervous system. According to the World Health Organisation, multiple sclerosis affects about 2.5m individuals worldwide, of which about 1% die each year. [My note: Of course, a little over 1% of the general population die each year as well - no one lives forever]
What is multiple sclerosis?
Mutiple sclerosis attacks the nervous system. Initially it causes loss of balance, reduced vision and bouts of localised paralysis.
Eventually, patients may become totally paralysed and wheelchair-bound.
There are several kinds of mutiple sclerosis.
Relapsing-remitting MS patients initially experience one or more bouts of illness, followed by complete or partial recovery. Patients are clinically stable between relapses.
Progressive MS patients become gradually more disabled.
Secondary-progressive MS patients start out with the relapsing-remitting form of the disease, but then experience gradual progression of disability.
What causes multiple sclerosis?
Multiple sclerosis appears to be caused by a chemical found naturally in the body called interferon gamma. Under normal circumstances this chemical helps to activate the immune system to attack foreign invaders, such as viruses and bacteria.
In multiple sclerosis patients interferon gamma causes the immune system wrongly to identify body cells are foreign invaders.
As a result, the myelin sheath coating nerves in the brain and spinal cord is destroyed by mistake.
As a consequence, tranmission between nerve cells slows down and becomes irregular.
What treatment is available?
The drug beta interferon is used to treat people suffering from auto-immune diseases such as multiple sclerosis.
All the interferons - alpha, beta and gamma - are found naturally in the body, and all play a crucial role in the proper functioning of the immune system.
Beta interferon inhibits the action of gamma interferon and also stimulates agents that suppress immune activity.
Beta interferon can be manufactured using genetic engineering. Manufactured beta interferon was first marketed by Schering as Betaferon (beta-1b). Subsequently a new type (beta-1a) has been produced by Serono as Rebif and Biogen as Avonex.
Why is beta interferon controversial?
Trials of Beta Interferon do not indicate that it is a cure for MS, but do suggest that it can help people with the relapsing/remitting form of the disease by reducing the frequency and severity of relapses and slowing the progression of disability. Trials on patients with progressive MS are ongoing.
However the full impact of the drug has yet to be established, and because it is very costly - approximately £10,000 per patient per year - some health authorities are reluctant to allow it to be prescribed.
For whom will beta interferon be considered?
At present, patients with relapsing/remitting MS will be considered for beta interferon. However, because no impact has yet been discovered on the progression of disability among people with progressive MS, it is unlikely that the drug will be prescribed for people who are severely disabled.
What are the side effects?
Short term side effects vary depending on the type of beta interferon used, but may include inflammation at the site of the injection and flu-like symptoms. Some people have reported depression. It is too early to tell what the long tem side effects will be. The patient's health - and response to treatment - will be monitored by a doctor.
Are there special considerations?
The impact upon a developing baby is as yet unknown, and beta inteferon should not be given to women who are pregnant, planning pregnancy or who are breast feeding. The drug may not be prescribed if the patient suffers from other medical problems.
This page contains basic information. If you are concerned about your
health, you should consult a doctor.