Guardrails for Blood-Based Biomarker Testing in Specialty Care: Rebecca Edelmayer, PhD

WATCH TIME: 3 minutes

"Not all blood tests perform the same, and our guidance reflects that. For now, use BBMs in cognitively impaired patients in specialized settings as triage or confirmatory tools while the evidence base grows."

In recent years, there have been a number of emerging biomarkers for Alzheimer disease (AD), most notably amyloid-ß, followed by phosphorylated tau, neurofilament light, and glial fibrillary acidic protein. Biomarkers remain critical for helping identify at-risk patients earlier, even at mild cognitive impairment stages. Currently, there are several innovative tests being used in specialty care, including single molecule arrays, multi-analyte panels, and commercially available and near-clinical tests, such as PrecivityAD and ALZpath pTau217 ELISA.

While these advancements have been a great resource for the clinical community, there’s still a lot of education and learning that comes with them. During the Alzheimer’s Association International Conference (AAIC), held late July in Toronto, Canada, the organization unveiled its first clinical practice guideline on the use of blood-based biomarker tests. There are a few main takeaways from the recommendations, including that:

• BBM tests with ≥90% sensitivity and ≥75% specificity can be used as triage tools: a negative rules out Alzheimer’s pathology, while a positive should be confirmed with CSF or amyloid PET.
• BBM tests with ≥90% sensitivity and specificity may serve as substitutes for PET amyloid imaging or CSF biomarker testing.

Following the publication of the guidelines, Rebecca Edelmayer, PhD, vice president of scientific engagement at the Alzheimer’s Association, sat down to discuss the guidelines in depth. Edelmayer spoke about how the guideline supports assay-specific use in cognitively impaired clinics, while deferring recommendations for primary care or asymptomatic individuals until stronger evidence emerges. Overall, she spoke on some of the specific considerations, including the need to match blood-based testing to the right patient population and setting, while interpreting results within known assay limits.