A significant announcement was made at the Alzheimer’s Association International Conference (AAIC) 2025, which was held in Toronto, regarding the future of dementia diagnosis. The Alzheimer’s Association has issued the first clinical practice guidelines (CPG) for the use of blood-based biomarker (BBM) tests to diagnose Alzheimer’s disease. The CPG provides clear, brand-neutral, and evidence-based guidelines to support more accessible and accurate diagnosis of Alzheimer’s disease by using BBM tests. These suggestions are associated with a systematic review using transparent and robust methods.
These new guidelines support clinicians in using BBM tests consistently and confidently, enabling faster, more accurate, and accessible diagnoses. It applies only to patients who have cognitive impairments to improve results for patients and families affected by Alzheimer’s disease.
The BBM test is used as a triaging test. It has ≥75% specificity and ≥90% sensitivity; they are effective in ruling out Alzheimer’s pathology when results are negative. A positive test result must be confirmed by another method, such as amyloid positron emission tomography (PET) or a cerebrospinal fluid (CSF) test. BBM test with ≥90% specificity and sensitivity can be used instead of the PET amyloid imaging test or the CSF Alzheimer’s biomarker test.
This guideline emphasizes the variability in the accuracy of diagnostic tests, with many commercially marketed BBM tests that cannot meet certain standards. It highlights the necessity for clinicians to use these tools appropriately to avoid misuse and ensure that patients benefit from validated, evidence-based diagnostics.
BBM tests are more accessible, acceptable, and less costly to patients than CSF tests and PET imaging. This is the first evidence-based recommendation in Alzheimer’s disease by using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) method. The usage of GRADE ensures a structured, transparent, and evidence-based procedure to evaluate the degree of certainty and develop recommendations. The main audience involved specialists who diagnose and evaluate cognitive impairments. Amyloid-beta (Aβ) and plasma phosphorylated-tau (p-tau) tests measure the ratio of Aβ42 to Aβ40, the ratio of p-tau217 to non-p-tau217 ×100 (%p-tau217), p-tau231, p-tau181, and p-tau217. The two biomarkers linked to Alzheimer’s disease, tau or amyloid beta protein, are evaluated by different BBM tests.
The CPG is a component of ALZPro™. It is the Alzheimer’s Association’s comprehensive center of tools to provide best practices, improve care, expand equitable access, advance early detection, and empower healthcare providers in all disciplines to decrease the risk.
BBMs have significantly altered the diagnostic approach of Alzheimer’s disease with several new clinical implementations. Accurate early diagnosis and accessibility of anti-Aβ treatment for early symptomatic Alzheimer’s disease are significantly important. The Alzheimer’s Association assembled a multidisciplinary panel of clinicians, guidelines methodologists, and subject matter experts to perform a systematic review and establish evidence-based guidelines to use BBM in the diagnosis of Alzheimer’s disease. The guidelines are focused on patients who have cognitive impairment, whether dementia or MCI, who are having diagnostic evaluation in secondary or tertiary care.
The panel used the GRADE method to evaluate the certainty of evidence and the GRADE evidence to disease framework to establish the guidelines. From 49 observational studies, approximately 31 different BBM tests were evaluated to determine their diagnostic accuracy. The test accuracy can be used as a triaging test, a confirmatory test, instead of a CSF or PET test, or not sufficient to suggest for current use in clinical settings.
BBMs can enhance the early diagnosis of Alzheimer’s disease and increase access to disease-modifying therapies. Evidence-based recommendations are key to standardizing the usage. It can be updated with new evidence and application.
References: Alzheimer’s Association. From the Alzheimer’s Association International Conference 2025: Alzheimer’s Association releases its first clinical practice guideline for blood-based biomarker tests. PR Newswire. Published July 29, 2025.
