A major medical group is recommending that specialists use certain blood tests to diagnose patients with cognitive impairment, potentially leading to more people receiving treatment for Alzheimer’s disease. The Alzheimer’s Association has released its first clinical guidelines on blood biomarker testing, which suggest that tests with over 90% sensitivity and specificity can be used instead of invasive methods like PET scans.
The guidelines recommend using blood tests to triage patients, meaning that negative results can rule out Alzheimer’s, but positive results should be confirmed with standard diagnostic methods. However, the authors stress that these tests should not replace a full clinical evaluation and are only suitable for patients already diagnosed with cognitive impairment under specialist care.
Several blood tests have been reviewed, including those measuring biomarkers such as pTau217 and the ratio of Aβ42 to Aβ40. The Alzheimer’s Association will post a chart of the various tests and their accuracy on its online portal, which will be updated regularly.
While the guidelines may not address monitoring patients receiving treatment, they are expected to lead to more people getting tested and diagnosed, particularly in rural areas where access to scans is limited. Experts say that these blood tests offer a convenient and cheaper alternative for diagnosis, but caution that they have limitations, including false positives.
The approval of new Alzheimer’s drugs has sparked a push for blood tests, with the FDA having already approved one test. The guidelines aim to provide clear guidance on when to use these tests, which will be updated over time.
Source: https://www.statnews.com/2025/07/29/alzheimers-blood-tests-new-diagnosis-guidelines