Blood-based test holds potential to 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 could be used to predict the risk of Alzheimer's disease up to 3.5 years before clinical diagnosis.

The study, published in the journal Brain, supports the idea that components in the human blood can modulate the formation of new brain cells, a process termed neurogenesis. Neurogenesis occurs in an important part of the brain called the hippocampus that is involved in learning and memory.

To understand the early changes, researchers collected blood samples over several years from 56 individuals with Mild Cognitive Impairment (MCI).Of the 56 participants in the study, 36 went on to receive a diagnosis of Alzheimer’s disease.

The blood samples collected from participants over the years who subsequently deteriorated and developed Alzheimer’s disease promoted a decrease in cell growth and division and an increase in apoptotic cell death. However, the researchers noted that these samples also increased the conversion of immature brain cells to hippocampal neurons.

While the underlying reasons for the increased neurogenesis remain unclear, the researchers theorise that it may be an early compensating mechanism for the neurodegeneration (loss of brain cells) experienced by those developing Alzheimer’s disease. When the researchers used only the blood samples collected furthest away from when the participants were diagnosed with Alzheimer’s disease, they found that the changes in neurogenesis occurred 3.5 years prior to a clinical diagnosis.

Reference:

Predicting progression to Alzheimer’s disease with human hippocampal progenitors exposed to serum,Brain,10.1093/brain/awac472