New test can detect Alzheimer’s disease 3.5 years before clinical diagnosis

New research from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King’s College London has established a blood-based test that can be used to predict the risk of Alzheimer’s by up to 3, 5 years before clinical diagnosis.

The study was published in the journal Brainsupports the idea that components in human blood Can adjust the formation of new brain cell, a process called neurogenesis. Neurogenesis occurs in an important part of the brain called the hippocampus that is involved in learning and memory.

While Alzheimer’s disease pandemic affect the formation of new brain cells in the hippocampus during the early stages of the disease, previous studies were only able to study neurogenesis in later stages through autopsies.

To understand the initial changes, the researchers collected blood samples over several years from 56 individuals with Mild Cognitive Impairment (MCI), a condition in which someone will begin to feel their memory or cognitive abilities get worse. Although not everyone who undergoes MCI develops Alzheimer’s disease, people with the condition progress to a diagnosis at a much higher rate than the broader population. Of the 56 study participants, 36 went on to be diagnosed with Alzheimer’s disease.

Dr Aleksandra Maruszak, one of the first authors of the study from King’s IoPPN explains: “In our study, we treated brain cells with blood taken from people with MCI, discovering how those cells change in response to the blood as Alzheimer’s disease progresses.”

In studying how blood affects brain cells, researchers have made a number of important discoveries. Blood samples collected from participants over several years, who subsequently declined and developed Alzheimer’s disease promoted the reduction cell growth and division and an increase in programmed cell death (the process by which cells are programmed to die). However, the researchers note that these samples also increased the conversion of immature brain cells into hippocampal neurons.

Although the underlying reasons for the increase in neurogenesis remain unclear, the researchers hypothesized that it may be an early compensatory mechanism for neurodegeneration (loss of brain cells) experienced by people with Alzheimer’s disease.

Professor Sandrine Thuret, lead author of the study from King’s IoPPN, said: “Previous studies have shown that blood from young mice can have a rejuvenating effect on the cognitive abilities of aged mice. by improving hippocampal neurogenesis, which gave us the idea to model neuron formation in a dish using human brain cells and human blood. In our study, we aimed to use this model to understand neurogenesis and use changes in this process to predict Alzheimer’s disease, and found the first evidence in humans that the system The body’s circulatory system can affect the brain’s ability to form new cells.”

When researchers only used blood sample furthest collected since participants were diagnosed with Alzheimer’s, they found that changes in neurogenesis occurred 3.5 years before the patients developed Alzheimer’s disease. clinical diagnosis.

Dr Edina Silajdžić, co-first author of the study added: “Our findings are extremely important, potentially allowing us to predict early onset of Alzheimer’s disease in a non-invasive way. This could complement other blood-based biomarkers that reflect classical markers of disease, such as the accumulation of amyloid and tau (the ‘leading’ protein of Alzheimer’s disease).”

“It is now essential to validate these findings in a larger and more diverse group of people. We are excited about potential applications,” said Dr. Hyunah Lee, first author of the study. of the blood-based test we’ve used. It could, for example, help stratify individuals with memory problems for clinical trials of disease-modifying drugs for Alzheimer’s disease.”

The researchers say the findings may offer an opportunity to better understand the changes in brain experiencing the earliest stages of Alzheimer’s disease.