London, Oct 15 (UNI) Scientists have created a blood test that can detect Alzheimer's six years before patients develop the dementia causing disease.
The revolutionary development will help the doctors to detect those who are at highest risk of developing the degenerative disease that has affected 24 million people worldwide.
Quicker detection would now allow earlier prescription of treatments and also give sufferers and their families more time to prepare for the future.
The test will mostly benefit the people with a strong family history of the disease. It could also prove invaluable in determining the difference between simple forgetfulness and the early stages of Alzheimer's.
However, fears have been expressed that insurance companies could cash in on the advance hiking premiums for those at risk, or even refusing to insure them altogether.
Current diagnosis is based on a patient's symptoms and on ruling out the presence of other conditions linked to memory loss, such as stroke and brain tumours.
The only foolproof evidence of the presence of the disease comes from examination of the patient's brain after they have died.
The blood test, which is up to 90 per cent accurate, picks up telltale changes in the blood proteins that cells in the brain and body use to send messages to one another.
The US researchers said the test allowed them to 'listen' for abnormalities linked to Alzheimer's.
''Just as a psychiatrist can conclude a lot of things by listening to the words of a patient, so by 'listening' to different proteins, we are measuring what is going wrong in the cells,'' Stanford University Dr Tony Wyss-Coray was quoted as saying by Daily Mail.
''Our data indicate blood contains a highly-specific biological signature that can characterise Alzheimer's disease years before a clinical diagnosis can be made,'' he said.
The test was also able to differentiate between Alzheimer's and other forms of dementia, the journal Nature Medicine reports.
It is hoped the test will be available for use in research labs next year, however, further large-scale tests are needed before it is given the go-ahead for general use by doctors.
Used in combination with new drugs which are being developed, the test will help people from reaching the devastating final stages of the illness, in which loss of the ability to walk, talk and even swallow leaves sufferers totally dependant on others.
British experts on Alzheimer's welcomed the latest breakthrough, but warned that the test is still several years away from the market.