New Blood Test Shows Promise for Early Alzheimer’s Detection

Recent research indicates that a new blood test for Alzheimer’s disease can effectively identify individuals with early symptoms of the condition.

Experts from the Mayo Clinic have provided supporting evidence that blood tests can indeed diagnose dementia accurately by analyzing two specific proteins found in blood plasma.

These proteins—amyloid beta 42/40 and p-tau217—are linked to the accumulation of amyloid plaques, a defining characteristic of Alzheimer’s disease.

According to the study, the blood test boasts a remarkable 95% sensitivity, meaning it successfully detects memory issues in most cases, with very few missed. Additionally, the test shows 82% specificity, indicating a strong ability to rule out those without dementia.

This research involved over 500 participants at an outpatient memory clinic, which suggests the findings reflect real-world scenarios.

The blood test has received approval from the Food and Drug Administration in the US.

Dr. Gregg Day, who led the study published in the journal Alzheimer’s and Dementia, noted that the blood test performs similarly to more invasive testing methods currently in use.

“Our study found that blood testing affirmed the diagnosis of Alzheimer’s disease with 95% sensitivity and 82% specificity,” he mentioned. “When utilized in an outpatient clinical setting, this is comparable to the accuracy of cerebrospinal fluid biomarkers, offering a more convenient and cost-effective option.”

Overall, researchers observed that levels of p-tau217 were significantly higher in Alzheimer’s patients compared to those who did not have the disease.

Dr. Day added that future research will focus on evaluating blood-based testing in a more diverse patient population, particularly those with early Alzheimer’s who may not yet show cognitive symptoms.

Dr. Richard Oakley, associate director for research at the Alzheimer’s Society in the UK, remarked that the results “suggest this test is very accurate” and could complement other tests and professional observations.

“This study indicates that blood tests are making Alzheimer’s diagnosis quicker, easier, and more accessible than ever in practical settings,” he said.

While the test focuses on Alzheimer’s, it was also assessed in individuals with other types of dementia, hinting that it may assist in distinguishing various causes of cognitive decline. However, further research in diverse groups and community settings is necessary.

“Currently, diagnosis options in the UK can be slow, costly, and invasive, leading many to miss out on potential benefits one would gain from an earlier diagnosis,” he added. “It’s encouraging to see such blood tests approved for clinical use in the US, and we hope to see similar advancements in the NHS, which is why we’re contributing to the Blood Biomarker Challenge.”

The Blood Biomarker Challenge is a significant research initiative supported by the Alzheimer’s Society, Alzheimer’s Research UK, and the National Institute for Health and Care Research. Its aim is to make blood tests for dementia diagnosis available through the National Health Service by 2029.

Oakley stressed that “Blood tests will be essential to speed up diagnoses and provide more individuals with the care and treatments they urgently need.” He emphasized the importance of sustained investment in the necessary tools and workforce to ensure early and accurate diagnoses for all those living with dementia, especially with disease-modifying treatments on the horizon.

Dr. Julia Dudley, head of research at Alzheimer’s Research UK, stated, “We critically need to enhance our dementia diagnostic methods, and it’s reassuring to witness international research pushing towards this aim.”

She emphasized that the blood tests analyzed p-tau217 and amyloid beta 42/40, demonstrating high accuracy in confirming Alzheimer’s disease. “This adds to the growing evidence that blood tests can identify diseases causing dementia in individuals with initial memory and thinking challenges,” she noted.

However, she pointed out that research participants may not always reflect the full diversity of the dementia-affected population, which might include individuals with other conditions. Therefore, it’s crucial to understand how these blood tests perform in practical settings.

In the UK, initiatives like the Blood Biomarker Challenge are helping to build this evidence base. This study aims to test blood tests, including p-tau217, across thousands of individuals in various locations throughout the UK.

“This effort will be vital for making diagnoses quicker and easier, getting us closer to finding a cure,” she concluded.