Early Blood Test To Predict Dementia Is Step Closer As Biological Markets Identified

Researchers have made significant progress toward developing a blood test that can predict the risk of dementia up to 15 years before clinical diagnosis. The Guardian reports: Hopes for the test were raised after scientists discovered biological markers for the condition in blood samples collected from more than 50,000 healthy volunteers enrolled in the UK Biobank project. Analysis of the blood identified patterns of four proteins that predicted the onset of dementia in general, and Alzheimer's disease and vascular dementia specifically, in older age. When combined with more conventional risk factors such as age, sex, education and genetic susceptibility, the protein profiles allowed researchers to predict dementia with an estimated 90% accuracy nearly 15 years before people received clinical confirmation of the disease. For the latest study, blood samples from 52,645 UK adults without dementia were collected and frozen between 2006 and 2010 and analyzed 10 to 15 years later. More than 1,400 participants went on to develop dementia. Using artificial intelligence, the researchers looked for connections between nearly 1,500 blood proteins and developing dementia years later. Writing in Nature Aging, they describe how four proteins, Gfap, Nefl, Gdf15 and Ltbp2, were present in unusual levels among those who developed all-cause dementia, Alzheimer's disease or vascular dementia. Higher levels of the proteins were warning signs of disease. Inflammation in the brain can trigger cells called astrocytes to over-produce Gfap, a known biomarker for Alzheimer's. People with raised Gfap were more than twice as likely to develop dementia than those with lower levels. Another blood protein, Nefl, is linked to nerve fibre damage, while higher than normal Gdf15 can occur after damage to the brain's blood vessels. Rising levels of Gfap and Ltbp2 was highly specific for dementia rather than other brain diseases, the scientists found, with changes occurring at least 10 years before people received a dementia diagnosis. The researchers are speaking to companies to develop the test but said the cost, currently at several hundred pounds, would need to come down to make it viable.

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