Breakthrough blood test diagnoses Alzheimer's early with 95% accuracy

New research shows that a blood test for Alzheimer's can accurately spot early symptoms. Experts from the Mayo Clinic in the US presented new evidence endorsing the idea that blood tests can reliably spot dementia by examining two proteins in the plasma.

The markers called amyloid beta 42/40 and p-tau217 are associated with the formation of amyloid plaques, a major sign of Alzheimer's disease. The researchers were excited to find that the blood test showcased a remarkable 95% sensitivity rate - it was highly effective at detecting those with cognitive impairments and missed very few cases.

The test also posted an 82% specificity rate, successfully ruling out people without dementia. The investigation involved over 500 subjects from an outpatient memory clinic, thus providing data reflective of real-world scenarios. This groundbreaking test has been endorsed by the Food and Drug Administration (FDA) in the US, reports Surrey Live.

At present, it is estimated that 982,000 individuals in the UK are living with dementia, and this number is expected to increase to 1.4 million by 2040. The magnitude of the situation and the necessity to prevent, diagnose, support, and ensure a good quality of life for those living with dementia will only intensify.

Dr Gregg Day, the lead researcher behind the findings published in the Alzheimer's and Dementia journal, acclaimed the blood test as being on par with more intrusive diagnostic methods used today. "Our study found that blood testing affirmed the diagnosis of Alzheimer's disease with 95% sensitivity and 82% specificity," he confirmed.

Researchers discovered that p-tau217 levels were significantly higher in patients with Alzheimer's disease compared to those without the condition. "When performed in the outpatient clinical setting, this is similar to the accuracy of cerebrospinal fluid biomarkers of the disease and is much more convenient and cost-effective."

According to Dr Day, the next stages of the research will involve evaluating blood-based tests in a broader range of patient groups, including those with early Alzheimer's who do not display any cognitive symptoms.

Dr Richard Oakley, Associate Director for Research and Innovation at the Alzheimer's Society in the UK, noted that the findings suggest this test is highly accurate and may be used in conjunction with other assessments and clinical observations.

He added: "This study shows how blood tests are making diagnosis of Alzheimer's disease quicker, easier and more accessible than ever before in a real-world setting. While focused on Alzheimer's disease, the test was evaluated in people with other types of dementias, too, showing that it may help with differentiating causes of cognitive decline, though more research in diverse groups of individuals and in community-based settings is still needed."

He explained: "Currently diagnosis options in the UK are often slow, expensive and can be invasive, meaning thousands miss out on the benefits one can bring. It's great to see blood tests like this approved for clinical use in the US – we hope to see the same in the NHS, which is why we're part of the Blood Biomarker Challenge."

The Blood Biomarker Challenge is a multi-million pound research endeavour supported by the Alzheimer's Society, Alzheimer's Research UK, and the National Institute for Health and Care Research. The project's goal is to roll out blood tests for dementia diagnosis within the NHS by the year 2029.

Dr Oakley said: "Blood tests will be critical to accelerate diagnosis and give more people access to the care, support and treatments they desperately need faster than ever before. We must see long-term investment in the tools and workforce needed to ensure everyone living with dementia can get an early and accurate diagnosis, which is even more important with disease-modifying treatments on the horizon."

Dr Julia Dudley, head of research at Alzheimer's Research UK, weighed in on the breakthrough. She said: "We urgently need to improve how we diagnose dementia, and it's great to see international research working towards this goal. Blood tests in this study looked at p-tau217 and amyloid beta 42/40 and showed that the tests offered high accuracy in confirming Alzheimer's disease.

"This study adds to the growing evidence that blood tests can detect the diseases that cause dementia in people with early memory and thinking problems. An important point to consider is that people taking part in research don't always reflect the full diversity of those affected by dementia, who might have additional conditions or other characteristics."

However, there is a need for further investigation into the efficacy of these blood tests under real-world circumstances. As stated by the expert: "That is why work is needed to understand whether these blood tests work in a real-world setting. In the UK, studies like the Blood Biomarker Challenge are helping to build this evidence. The study is testing blood tests, including p-tau217, in thousands of people from sites across the UK. This work will be a crucial part of making diagnosis easier and faster, which will bring us closer to a cure."

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Alzheimer's disease is at the forefront of dementia causes within the UK, associated with a steady degeneration of brain capabilities, disturbing memory, thought processes, and other mental faculties. Despite intense scientific efforts, the precise origins of Alzheimer's continue to elude understanding, but it is recognised that several risk factors may contribute to the likelihood of developing the disease.

The NHS has highlighted: "The first sign of Alzheimer's disease is usually minor memory problems. For example, this could be forgetting about recent conversations or events, and forgetting the names of places and objects. As the condition develops, memory problems become more severe and further symptoms can develop."

• confusion, disorientation and getting lost in familiar places
• difficulty planning or making decisions
• problems with speech and language
• problems moving around without assistance or performing self-care tasks
• personality changes, such as becoming aggressive, demanding and suspicious of others
• hallucinations (seeing or hearing things that are not there) and delusions (believing things that are untrue)
• low mood or anxiety

Such issues may signal the onset of Alzheimer's disease, a condition attributed to abnormal protein build-ups in the brain. It is thought that Alzheimer's disease arises due to an unusual accumulation of proteins near and within brain cells. The protein amyloid is associated with the formation of plaques around brain cells, playing a key role in this condition.

Another protein called tau causes tangles to form inside brain cells. Although scientists have yet to pinpoint the exact cause of this process, it is known to begin years before any symptoms are observed.