A blood test that could spot early signs of Alzheimer’s is being perfected by scientists.
The particular group of peptides, called beta amyloid (A), are found naturally in the body, and a build-up in the brain over a period of years causes memory complaints and other symptoms associated with the disease.
Professor Manuel Sarasa, the chief scientific officer and founder of Araclon Biotech, and his team have been perfecting blood tests “ABtest40” and “ABtest42” to measure tiny amounts of the peptides.
He said: “The study has shown that our tests for A in blood find a high level of association between the peptide levels and the disease when comparing healthy people and people with mild cognitive impairment.”
“By measuring three different levels in blood, free in plasma, bound to plasma components and bound to blood cells, for two of the most significant peptides, A40 and A42, then comparing the ratios of those levels to established diagnoses methods, we have been able to consistently show a relationship between A levels and the disease.”
“This means that we, and by ‘we’ I mean Alzheimer’s’ researchers in general, are that much closer to having a reliable, minimally invasive biomarker for Alzheimer’s disease.”
He added: “The importance of this is that studies could recruit earlier and at much less expense.
“Interventional therapies can be tested in earlier stages of the disease and once an effective therapy is found, this type of test will be well suited to population screening in the public health sector.”
The results of the research are being published in the Journal of Alzheimer’s Disease in July.
Researchers from the University of Nottingham in the U.K. say their test looks for a combination of markers in the blood that wave red flags for the neurodegenerative illness. These flags include amyloids, the misfolded proteins that can accumulate in plaques in the brain; apolipoprotein E, or ApoE, a variant of which is linked to Alzheimer’s; and other proteins linked to inflammation.
“Our findings are exciting because they show that it is technically possible to distinguish between healthy people and those with Alzheimer’s using a blood test,” University of Nottingham professor Kevin Morgan told the BBC. “As blood tests are a fast and easy way of aiding diagnosis, we are really encouraged by these findings and the potential they hold for the future.”
But don’t hold your breath: it could be 10 years or more before the test is available to patients.
When the test does become available, it could be used to screen people for the disease long before symptoms appear.
“The way we see it working is you can test people and it will tell them if they have the all-clear, or if they are medium- or high-risk,” Morgan told the BBC. “If they are medium-risk, they can be monitored closely and high-risk patients can be referred to a specialist for more in-depth testing.”
Meanwhile, a cure for Alzheimer’s is still a long way off.
“We’ve had a lot of failures in Alzheimer’s drugs. But you learn from them,” Guy Eakin, vice president of scientific affairs at the American Health Assistance Foundation, said last May.
In May 2012, federal officials announced the start of the first clinical trial of a drug aimed at actually preventing – not just treating or curing — Alzheimer’s disease.
The trial – a $100 million collaboration between the U.S. National Institutes of Health, the Arizona-based Banner Alzheimer’s Institute, drug giant Genentech and the University of Antioquia in Colombia between — approaches the disease from an unusual angle. Instead of testing drugs on patients with full-blown dementia, the trial focuses on around 300 people in the U.S. and Colombia that carry a genetic mutation that usually triggers Alzheimer’s symptoms around age 45. Most of the study subjects are from a single large extended family.
Prevention efforts for Alzheimer’s focus on a mutation that affects the gene PSEN1, which is involved in the production amyloid protein. Clumps of beta amyloid proteins, known as plaques, and smaller aggregations of amyloid known as ‘ligomers’ are thought to play a key role in Alzheimer’s disease when they build up in the brain.
Crenezumab, the drug being tested, is an antibody that binds to beta amyloid and helps clear out those excessive deposits.