Blood-based test could detect Alzheimer’s disease early, study suggests 

A test could detect Alzheimer’s disease three and a half years before it is diagnosed, a study suggests.

The research from the Institute of Psychiatry, Psychology & Neuroscience at King’s College London established a blood-based test that could predict the risk of the condition. The study supports the idea that components in blood can influence the formation of brain cells.

Dr Edina Silajdzic, the study’s joint first author, said: ‘Our findings are extremely important, potentially allowing us to predict onset of Alzheimer’s early.’

While Alzheimer’s 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 a number of years researchers collected blood samples from 56 people with mild cognitive impairment (MCI), a condition where someone will begin to experience a worsening of their memory or cognitive ability.

While not everyone with MCI will develop Alzheimer’s disease, those with the condition progress to a diagnosis at a much higher rate than the wider population.

Thirty-six of the 56 people in the study went on to be diagnosed with Alzheimer’s.

When the researchers used only the blood samples collected furthest away from when someone was diagnosed with Alzheimer’s disease, they found that the changes in neurogenesis occurred 3.5 years before a clinical diagnosis.

Professor Sandrine Thuret, the study’s lead author from King’s IoPPN, said: ‘Previous studies have shown that blood from young mice can have a rejuvenating effect on the cognition of older mice by improving hippocampal neurogenesis.

‘This gave us the idea of modelling the process of neurogenesis in a dish using human brain cells and human blood.

‘In our study, we aimed 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.’