The Elecsys pTau181 blood test correctly identified people without Alzheimer\u2019s in 97.9% of cases<\/p>\n<\/h3>\n
By I. Edwards HealthDay Reporter<\/b>
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WEDNESDAY, Oct. 15, 2025 (HealthDay News) \u2014 The U.S. Food and Drug Administration (FDA) has cleared another blood test that could help doctors identify whether a patient\u2019s memory problems are likely caused by Alzheimer\u2019s disease<\/a>.<\/p>\n The new test, called Elecsys pTau181, was developed by Roche Diagnostics<\/a> in partnership with Eli Lilly<\/a>. It\u2019s designed for adults 55 and older who are showing early signs of cognitive decline.<\/p>\n \u201cBy bringing Alzheimer\u2019s blood-based biomarker testing into primary care, we can help patients and their clinicians get answers sooner to support them earlier in their journeys,\u201d Brad Moore<\/a>, president and CEO of Roche Diagnostics North America, told CNN.<\/em><\/p>\n The Elecsys test measures levels of pTau181, a protein found in blood plasma. Higher levels of this protein are linked to Alzheimer\u2019s and other brain diseases.<\/p>\n In a study involving 312 people, the test correctly ruled out Alzheimer\u2019s disease 97.9% of the time, according to Roche.<\/p>\n \u201cWhen the test result is negative, there\u2019s a very high likelihood the person does not have Alzheimer\u2019s-related pathology,” said Laura Parnas<\/a>, director of medical and scientific affairs at Roche Diagnostics.<\/p>\n \u201cHowever,” she added in a CNN <\/em>report, “it\u2019s important to note that for patients with a positive result, further clinical investigations and confirmatory testing for the amyloid pathology is needed for the final diagnosis of Alzheimer\u2019s.”<\/p>\n The Elecsys pTau181 test is the second blood test cleared by the FDA this year for use in Alzheimer\u2019s evaluation. In May, the agency approved Fujirebio\u2019s Lumipulse test, which detects a different set of proteins associated with the disease.<\/p>\n Experts predict that multiple testing options could improve how doctors assess brain health.<\/p>\n Having access to different blood-based tests that measure different biomarkers can help inform and provide a broader understanding of someone\u2019s brain health when testing for early Alzheimer\u2019s disease, Dr. Richard Isaacson<\/a>, a preventive neurologist and Alzheimer\u2019s researcher, told CNN.<\/em><\/p>\n \u201cTo more accurately stage disease and track progression over time, I never order one single test. I only order a panel of tests. We\u2019re not at the time yet where one marker is the \u2018be all and end all.\u2019 It\u2019s more complicated than that,\u201d he said. \u201cWhile there are now resources available to learn about Alzheimer\u2019s risk factors and what these new blood tests might mean, these are still early days.\u201d<\/p>\n Experts say these new tests are exciting, but doctors still need to be careful about how they use and interpret the results.<\/p>\n \u201cWe have to be very cautious with mass adoption of these blood tests because of the potential false positives,\u201d Isaacson said. \u201cThe medical field is still learning how to use these tests and how to apply these test results in clinical practice.\u201d<\/p>\n Still, Alzheimer\u2019s experts see the approval as a major step forward.<\/p>\n \u201cThis is another important step toward expanding access to Alzheimer\u2019s disease diagnostic tools,\u201d said Joanne Pike<\/a>, president and CEO of the Alzheimer\u2019s Association. <\/em><\/p>\n \u201cBy using a \u2018rule out\u2019 initial tool in the primary care setting, we can help people who are not living with Alzheimer\u2019s get to the root of their cognitive symptoms faster, while ensuring those who may have the disease are referred for appropriate testing, definitive diagnosis and early treatment,\u201d she added.<\/p>\n Roche said the Elecsys test will be available through its existing network of about 4,500 lab instruments across the United States.<\/p>\n More information<\/strong><\/p>\n The Mayo Clinic has more on Alzheimer’s<\/a>.<\/p>\n