Study paves way to predict Alzheimer's

Researcher sees early testing as apossible key to effective intervention

British scientists have identified a set of 10 proteins in the blood that can predict the onset of Alzheimer's, calling it an important step toward developing a test for the incurable brain-wasting disease.

Such a test could initially be used to select patients for clinical trials of experimental treatments being developed to try to halt the progression of Alzheimer's, the researchers said, and may one day move into routine use in doctors' clinics.

"Alzheimer's begins to affect the brain many years before patients are diagnosed. Many of our drug trials fail because by the time patients are given the drugs the brain has already been too severely affected," said Simon Lovestone of Oxford University, who led the work from King's College London.

"A simple blood test could help us identify patients at a much earlier stage to take part in new trials and hopefully develop treatments," he said.

Shares in the biotech company Proteome Sciences, which co-authored the study with scientists from King's College, jumped 12 percent on the news on Tuesday morning.

Alzheimer's is the most common form of dementia, which in 2010 was estimated in 2010 to be costing the world $604 billion a year. The disease affects 44 million people worldwide, with the number set to triple by 2050, the campaign group Alzheimer's Disease International said.

Several big pharmaceutical companies including Roche, Eli Lilly, Merck & Co and Johnson & Johnson, are pursuing various approaches to get to the root cause of Alzheimer's and try to find treatments to halt its progression.

Yet, over the past 15 years, more than 100 experimental Alzheimer's drugs have failed in trials. Lovestone and other experts believe this may be because drug trials are conducted too late, in patients whose condition has already gone too far. Alternative test.

Alternative test

A predictive test for use before people develop symptoms would help researchers select the right people for drug trials, and help show whether the experimental drugs are working.

Previous studies have found that PET brain scans and tests of lumbar fluid can be used to predict the onset of dementia from people with a less severe condition known as mild cognitive impairment, but these tests are expensive and invasive, so scientists are keen to develop a cheaper, simpler blood test.

MCI includes problems with day-to-day memory, language and attention. It can be an early sign of dementia, or a symptom of stress or anxiety.

Around 10 percent of people diagnosed with MCI develop dementia within a year. Apart from regular assessments to measure memory decline, there is currently no accurate way of predicting who will or won't develop dementia.

Experts in the field welcomed the results but said they must be replicated in larger studies before an Alzheimer's blood test can be rolled out for use in doctors' clinics.

James Pickett, head of research at the Alzheimer's Society, said the research "does not mean that a blood test for dementia is just around the corner".

"These 10 proteins can predict conversion to dementia with less than 90 percent accuracy, meaning one in 10 people would get an incorrect result," he said. "Accuracy would need to be improved before it could be a useful diagnostic test."

(China Daily 07/09/2014 page10)