A fully automated blood test for Alzheimer’s disease has demonstrated diagnostic accuracy rivalling that of mass spectrometry-based plasma assays and standard cerebrospinal fluid testing, in a large multicentre clinical study across Europe. The assay, which measures plasma phosphorylated tau 217 (p-tau217), achieved over 90 percent accuracy for detecting Alzheimer’s pathology, offering a scalable, cost-effective alternative suitable for both primary and specialist care settings.
The study evaluated the Lumipulse immunoassay in 1,767 participants with cognitive symptoms across Sweden, Spain and Italy. Unlike previous blood biomarker studies based on mass spectrometry, the Lumipulse test uses a fully automated platform already in clinical use for other conditions, potentially allowing wider deployment.
“When the method was tested in patient groups, the accuracy was between 92 and 94 percent,” said Noëlle Warmenhoven, researcher and co-author at Lund University, in a press release. “This is very promising as this method is likely to become one of the more widely used methods in clinical practice worldwide, including Sweden.”
The assay works by detecting elevated levels of phosphorylated tau217 in blood plasma, a protein fragment linked to the accumulation of tau tangles in the brain – one of the hallmarks of Alzheimer’s pathology. The test uses chemiluminescent enzyme immunoassay technology to quantify p-tau217 concentrations via an automated analyser, reducing variation and allowing for high-throughput testing.
Using predefined cutoffs, the test correctly classified Alzheimer’s pathology with accuracies ranging from 89 to 94 percent in secondary care clinics and 85–92 percent in primary care, depending on whether a single or two-cutoff approach was applied. Introducing two cutoffs – one for likely positive, one for likely negative – reduced uncertainty by excluding intermediate results and improved overall diagnostic performance.
“Even with the simpler method of analysis, the blood test gives highly accurate results for Alzheimer’s disease pathology,” said Sebastian Palmqvist, associate professor at Lund University and co-lead of the study. “This makes the improved diagnostics more accessible to substantially more people worldwide.”
While the test's accuracy declined modestly in older adults when using a single cutoff – falling to 83 percent in those aged 80 or above – this limitation was mitigated by the two-cutoff strategy. The performance of the assay was otherwise unaffected by sex, diabetes, chronic kidney disease, APOE genotype, or disease stage.
The study also compared the Lumipulse assay with high-precision mass spectrometry-based measurements. In secondary care, the performance of the two approaches was similar. However, in primary care settings, mass spectrometry measurements of %p-tau217 achieved higher accuracy (90 percent) than Lumipulse (85 percent) when using a single cutoff. Nonetheless, the Lumipulse test remained highly effective when employing the two-cutoff strategy.
Importantly, the authors note that incorporating the blood test into standard diagnostic workflows could reduce reliance on invasive lumbar punctures and expensive amyloid PET imaging. Cost-effectiveness modelling suggests the test could lower diagnostic costs by up to 81 percent, depending on the local setting and the proportion of intermediate results.
“This is of great importance,” said Oskar Hansson, senior consultant at Skåne University Hospital, “as the disease is often misdiagnosed without biomarkers like this, and currently only a very small percentage of sufferers have access to these high-precision diagnostics.”
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