How Can Alzheimer's Disease Be Detected With Blood-based Biomarkers?

How Can Alzheimer’s Disease Be Detected With Blood-based Biomarkers?

In this video, PA Jordan Mast introduces blood-based biomarkers (BBMs) as an emerging tool to support earlier Alzheimer’s disease evaluation and timely patient education, referral, and support. He reviews which patients may benefit from BBM testing—those with objective cognitive impairment or verifiable symptoms—and explains how cognitive screening results and a comprehensive medical evaluation help determine when testing is appropriate.

PA Mast also breaks down common BBMs, including amyloid beta ratios and phosphorylated tau (p-tau) assays, and how accuracy varies across available tests. He discusses using BBMs to triage versus confirm suspected AD pathology, the role of two-cutoff approaches and “intermediate” results, and when additional confirmation with amyloid PET or CSF may be needed to guide next steps in care.

Key Takeaways:

Blood-based biomarker (BBM) testing should be ordered for patients who have objective cognitive impairment or verifiable symptoms of cognitive decline.
There are two markers that are generally used in BBM tests: amyloid beta and p-tau. Ratios of various analytes are used for testing.
Diagnostic accuracy varies across BBM tests.

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Speaker

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Jordan Mast, MMS, PA-C

References and Additional Resources:

Jacobson M, Thunell J, Zissimopoulos J. Cognitive assessment at Medicare’s annual wellness visit in fee-for-service and Medicare advantage plans. Health Aff. 2020;39:1935-1942. https://pubmed.ncbi.nlm.nih.gov/33136503/

Palmqvist S, Whitson HE, Allen LA, et al. Alzheimer’s Association clinical practice guideline on the use of blood-based biomarkers in the diagnostic workup of suspected Alzheimer’s disease within specialized care settings. Alzheimers Dement. 2025;21:e70535. https://pubmed.ncbi.nlm.nih.gov/40729527/

Atri A, Dickerson BC, Clevenger C, et al. Alzheimer’s Association clinical practice guideline for the Diagnostic Evaluation, Testing, Counseling, and Disclosure of Suspected Alzheimer’s Disease and Related Disorders (DETeCD‐ADRD): executive summary of recommendations for primary care. Alzheimers Dement. 2025;21:e14333. https://pubmed.ncbi.nlm.nih.gov/39713942/

Palmqvist S, Tideman P, Mattsson-Carlgren N, et al. Blood biomarkers to detect Alzheimer disease in primary care and secondary care. JAMA. 2024;332:1245-1257. https://pubmed.ncbi.nlm.nih.gov/39068545/

Bolton CJ, Rostamzadeh A, Chin N, et al. Disclosure of Alzheimer’s disease blood-based biomarker results in a primary care setting: opportunities and challenges. J Prev Alzheimers Dis. 2025;12:100310. https://pubmed.ncbi.nlm.nih.gov/40713244/

Grande G, Valletta M, Rizzuto D, et al. Blood-based biomarkers of Alzheimer’s disease and incident dementia in the community. Nat Med. 2025;31:2027-2035. https://pubmed.ncbi.nlm.nih.gov/40140622/

Ashton NJ, Brum WS, Di Molfetta G, et al. Diagnostic accuracy of a plasma phosphorylated tau 217 immunoassay for Alzheimer disease pathology. JAMA Neurol. 2024;81(3):255-263. https://pubmed.ncbi.nlm.nih.gov/38252443/

Schindler SE, Galasko D, Pereira AC, et al. Acceptable performance of blood biomarker tests of amyloid pathology — recommendations from the Global CEO Initiative on Alzheimer’s Disease. Nat Rev Neurol. 2024;20(7):426-439. https://pubmed.ncbi.nlm.nih.gov/38866966/

Hansson, O., Blennow, K., Zetterberg, H. et al. Blood biomarkers for Alzheimer’s disease in clinical practice and trials. Nat Aging 2023;3:506–519. https://pubmed.ncbi.nlm.nih.gov/37202517/

Supported by

Jordan Mast, MMS, PA-C

Jordan Mast is a board-certified physician associate (PA) with a focus on general neurology at the Colorado Neurological Clinic in Denver, CO. He attended Midwestern University and has over 13 years of experience practicing as a PA in neurology. Jordan Mast has a special interest in providing education to other healthcare providers, patients, and industry professionals regarding best practices in management of neurological conditions and often serves as a speaker and consultant for medical education. Throughout his career, he has participated in several phase 2-4 clinical trials across a range of neurological conditions including Alzheimer’s disease, multiple sclerosis, Parkinson’s disease, and stroke. With his involvement in clinical research, he has developed a strong passion for recognizing and treating Alzheimer’s disease. His family history of Alzheimer’s disease has helped develop this passion in treating patients and providing much needed care to the family members who are also affected.