by A new test could detect Alzheimer’s disease three and a half years before it is diagnosed, according to a new study.
New research from the Institute of Psychiatry, Psychology and Neuroscience (IoPPN) at King’s College London has established a blood test that could predict the risk of the disease.
The study supports the idea that components of human blood can influence the formation of new brain cells, a process called neurogenesis.
This process occurs in a part of the brain called the hippocampus which is involved in learning and memory.
While Alzheimer’s disease affects the formation of new brain cells in the hippocampus during the early stages of the disease, previous research has only been able to study neurogenesis in its later stages through post-mortem examinations. .
In order to understand the early changes, over several years, researchers took blood samples from 56 people with mild cognitive impairment (MCI), a condition in which a person will begin to experience worsening of their memory or cognitive abilities. .
Although not everyone with MCI develops Alzheimer’s disease, sufferers progress to diagnosis at a much higher rate than the general population.
Thirty-six of the 56 people in the study were later diagnosed with Alzheimer’s disease.
When researchers used only blood samples taken furthest from when a person was diagnosed with Alzheimer’s disease, they found changes in neurogenesis occur 3.5 years before a clinical diagnosis. .
Professor Sandrine Thuret, lead author of the King’s IoPPN study, said: ‘Previous studies have shown that blood from young mice may have a rejuvenating effect on cognition in older mice by enhancing neurogenesis in the hippocampus. .
“It gave us the idea to model the process of neurogenesis in a box using human brain cells and human blood.
“In our study, we sought to use this model to understand the process of neurogenesis and to use changes in this process to predict Alzheimer’s disease and found the first evidence in humans that the body’s circulatory system can have an effect on the brain’s ability to form. new cells.
According to research, blood samples taken from people who developed Alzheimer’s disease promoted decreased cell growth and division.
They also promoted an increase in apoptotic cell death – the process by which cells are programmed to die, according to the study.
Although the reasons for the increase in neurogenesis remain unclear, the researchers suggest that it may be an early compensation mechanism for the loss of brain cells experienced by people developing Alzheimer’s disease.
Dr Edina Silajdzic, co-lead author of the study, added: “Our findings are extremely important, as they potentially allow us to predict the early onset of Alzheimer’s disease in a non-invasive way.
“This could complement other blood biomarkers that reflect classic signs of the disease, such as amyloid and tau accumulation (the ‘flagship’ proteins of Alzheimer’s disease).”
The researchers say the findings, published in the journal Brain, could provide an opportunity to better understand the changes the brain undergoes in the early stages of Alzheimer’s disease.
