Scientists at CSIRO, Australia”s national science agency, have discovered more straightforward and less invasive approaches to improve the diagnosis of Alzheimer”s disease. This advancement has the potential to facilitate easier access for patients to new treatments, such as Donanemab, which was recently approved by the Therapeutic Goods Administration (TGA) for adults experiencing early symptoms of Alzheimer”s.
The confirmation of amyloid plaque in the brain is crucial for these treatments. Currently, the standard method for detecting amyloid plaque involves expensive PET scans or invasive lumbar punctures to analyze cerebrospinal fluid. In a recent study published in the journal Alzheimer”s and Dementia, researchers found that a combination of two blood tests—the Lumipulse plasma pTau217 test and the Aβ42/40 ratio test—could achieve accuracy comparable to the current gold standard methods.
Lead author Dr. James Doecke, a Research Scientist at CSIRO”s Australian e-Health Research Centre (AEHRC), emphasized the importance of blood tests in the triage process for developing suitable treatment strategies and understanding a patient”s position on the disease trajectory. “With treatments for Alzheimer”s disease biology becoming available, it”s critical we have accurate, scalable, and less invasive tests to identify eligible patients,” stated Dr. Doecke. “Our findings show this blood test combination performs at the level needed to confirm Alzheimer”s pathology.”
In collaboration with Edith Cowan University, The Florey Institute, Labcorp, and others, the AEHRC analyzed blood samples from nearly 400 participants sourced from the Australian Imaging, Biomarker and Lifestyle (AIBL) Study of Ageing. The results demonstrated that the combined pTau217/Aβ42 ratio achieved over 93 percent accuracy, similar to existing cerebrospinal fluid tests.
In the Intention-to-Treat cohort, sensitivity levels reached 99 percent, indicating that the tests correctly identified nearly all cases. Utilizing this combination of tests provided clinicians with highly reliable results, significantly reducing the number of uncertain cases by almost half. Co-author Colin Masters, a Professor of Dementia Research at The Florey Institute, remarked, “This is an important advance towards widespread adoption of blood tests in both clinical trials and everyday practice.”
The study underscores the potential of blood-based biomarkers to lessen the dependency on costly and invasive PET scans and lumbar punctures, thereby making the diagnosis of Alzheimer”s disease more accessible to patients and healthcare systems around the globe.
