Researcher handling test tubes in a laboratory_lab
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An international group of clinicians and researchers have agreed that Alzheimer’s disease blood biomarkers (BBMs) are a significant breakthrough, but are not yet ready for general clinical and primary care use.

Multiple research institutions have successfully pinpointed blood biomarkers that signal the presence of Alzheimer’s disease. Some have developed blood-based Alzheimer’s diagnostic tests as a proposed adjunct or eventual alternative to current diagnostics, which include costly brain scans and cerebrospinal fluid tests. But additional research is needed before these tests can be accepted as stand-alone biomarkers for primary care use, the panel said.

“Blood-based markers show promise for improving, and possibly even redefining, the diagnostic work-up for Alzheimer’s,” said Maria C. Carrillo, PhD, Alzheimer’s Association chief science officer and co-author of appropriate use recommendations published in Alzheimer’s & Dementia. “Remarkable progress has been made, but additional data are needed before BBMs can be used as a stand-alone test for diagnosis, and before considering broad use in primary care settings.”

The authors recommend that Alzheimer’s blood biomarkers are used “cautiously” in specialized memory clinics as part of diagnostic work-ups when confirmed with standard diagnostic scans. Shared data will help confirm their potential in general clinical use, they stated.

FDA pipeline

At least one blood test shown to detect amyloid beta brain plaques is being commercially marketed as an adjunct tool for cognitive health evaluations in primary care. The Food and Drug Administration in 2019 designated that test, PrecivityAD, as a breakthrough device in a program that supports expedited research for promising medical devices or device-led combination products.

Pharmaceutical company Roche in July announced that it has applied for FDA review for a blood biomarker diagnostics test that aims to help distinguish between Alzheimer’s and other causes of cognitive decline.

In May, the FDA cleared an in vitro diagnostic for the disease that uses a sample of cerebrospinal fluid to measure a ratio of beta-amyloid in the brain, producing results that have been shown to align with those of PET brain scans. This has opened the floodgates for requests for review of biomarker-based diagnostic tests, Fierce Biotech has reported.

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