Debating on the Clinical Utility of Blood-Based Biomarkers for Alzheimer Diagnosis: Fanny Elahi, MD, PhD

WATCH TIME: 5 minutes

"Ultimately, as we advance in our understanding of what are the blood-based biomarkers that can have the highest predictive value, they also provide cheap, scalable, highly informative—from a biological perspective—biomarkers that allow us to capture multiple different aspects of the aging brain and the vulnerable brain to degeneration."

Blood-based biomarkers are being investigated for their potential to improve diagnosis of Alzheimer disease (AD), particularly in light of recent developments in antiamyloid-β therapies. Plasma assays measuring phosphorylated tau (p-tau) have demonstrated diagnostic accuracy in differentiating AD from other neurodegenerative diseases and may help predict disease progression in patients with mild cognitive symptoms. Their implementation in clinical settings could potentially reduce the need for more invasive and expensive procedures. Additionally, these biomarkers are being used in clinical trials to identify patients in presymptomatic stages of AD and to monitor responses to new treatments over time.¹

Building on this growing research, in September 2024, Mount Sinai Health System announced it will be among the first in the world to implement blood-based biomarkers and confirmatory tests for AD and related dementia across both primary and specialty care settings. The organization noted that this effort is part of the Davos Alzheimer’s Collaborative Healthcare System Preparedness Accurate Diagnosis project. As part of the initiative, co-led by Fanny Elahi, MD, PhD, and Georges Naasan, MD, the Mount Sinai team will utilize the LucentAD p-Tau 217 assay, a noninvasive blood test, and will recruit 900 patients to help determine the most effective ways to integrate these biomarkers into clinical practice over 18 months.²

The project aligns with Elahi’s broader advocacy for blood-based biomarker use in neurodegenerative disease diagnosis. At the 2025 Alzheimer’s Association International Conference, held July 27-30, in Toronto, Canada, Fanny Elahi, MD, PhD, associate professor of neurology at Icahn School of Medicine, participated in a debate session where she defended the utility of blood biomarkers compared with imaging diagnostics. In a follow-up conversation with NeurologyLive^®, she expanded on their clinical promise, emphasizing their ability to detect early molecular disruptions that often precede structural changes in the brain. Elahi also underscored the importance of vascular health in brain aging, calling for biomarker panels that can capture the complexity of vascular pathology, a potentially critical factor in understanding dementia risk.

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REFERENCES
1. Hansson O, Blennow K, Zetterberg H, Dage J. Blood biomarkers for Alzheimer's disease in clinical practice and trials. Nat Aging. 2023;3(5):506-519. doi:10.1038/s43587-023-00403-3
2. Mount Sinai Health System Is First in Northeast to Use Blood Tests as an Early Detection Tool for Alzheimer’s Disease and Related Dementias in Patients. News Release. Mount Sinai Health System. Published September 12, 2024. Accessed July 28, 2025. https://www.mountsinai.org/about/newsroom/2024/mount-sinai-health-system-is-first-in-northeast-to-use-blood-tests-as-an-early-detection-tool-for-alzheimers-disease-and-related-dementias-in-patients