A new blood test may be key to diagnosing Alzheimer’s disease before the condition becomes debilitating.
Neuroscientists at New York University collected and analyzed the blood samples of 125 subjects for acetyl-L-carnitine (ALC) and free-carnitine, two markers essential for brain function.
These substances help to power cells, as well as regulate glutamate, which is involved in most brain activities.
When levels of ALC and free-carnitine drop, brain function follows. Additionally, reduced levels can lead to an excess amount of glutamate in the brain, which has been linked to mental health disorders closely tied to Alzheimer’s disease.
Levels of these markers were found to decline gradually, especially in women, from people with no signs of memory problems or slowed thinking to those with early signs of mild cognitive impairment (MCI).
Scientists involved in the research said the blood test could allow doctors to more easily detect, track and treat the disease.
Currently there is no one way to diagnose Alzheimer’s or track the efficacy of treatments. Patients must undergo rigorous clinical and laboratory testing, but because blood tests are noninvasive, this could be a more accessible way to detect the disease and monitor the efficacy of new drug therapies.
Study lead Dr Betty Bigio said the findings ‘offer the strongest evidence’ that levels of these substances could help in identifying people who have or are at greater risk of developing Alzheimer’s.
However, researchers stress more research is needed to reveal the sources of ALC and free carnitine and the processes that go into producing them, as well as how exactly they are related to cognitive decline.
Blood tests are noninvasive and could be a more accessible way to track the potential efficacy of new treatments (stock image)
Approximately four percent of all adults 65 and older have ever received a dementia diagnosis in the US – with Alzheimer’s disease the most common form of dementia, diagnosed in nearly 7million Americans.
And as the aging population of the US continues to grow, so will diagnoses. By 2050, the number of Alzheimer’s patients is projected to rise to nearly 13 million.
The study, published this week in the journal Molecular Psychiatry, involved 125 people from two separate studies conducted in Brazil and California.
Ninety-three people had been diagnosed with varying degrees of cognitive impairment and 32 study participants were cognitively healthy.
While the main cause of the dementia is still debated, scientists believe the disease is likely to be the result of an abnormal build-up of proteins – amyloid and tau – in and around brain cells.
In Alzheimer’s patients, amyloid proteins are not effectively cleared from the body and eventually form plaques in the brain.
Additionally, tau proteins detach from neurons and form tangles, causing neurons to die.
When neurons die, messages can’t be delivered as effectively throughout the brain, which scientists believe is what causes the thinking difficulties in dementia.
The above graph shows the estimated projection of Alzheimer’s disease patients in the US through 2060.
Using a combination of the measurements of ALC and free-carnitine together with amyloid and tau protein levels, researchers were able to diagnose Alzheimer’s patients with a 93 percent accuracy.
This is an increase from 80 percent accuracy when using the blood markers or proteins alone.
Senior study investigator Dr Carla Nasca said because declines ALC and and free carnitine closely corresponded with the severity of Alzheimer’s disease, the processes involved in their production could offer possible therapeutics ‘for getting at the root cause of the disease and potentially intervening before permanent brain damage occurs.’
While the current study found levels of the two markers could indicate the presence and degree of Alzheimer’s, Dr Nasca said more research is needed to discover the sources of ALC and free carnitine, as well as how they could be related to dementia.