The Alzheimer’s Association has published guidance regarding blood-based biomarker tests. The association announced the guidelines at their International Conference and in a release.
The Alzheimer’s Association recognized a need for “clear evidence-based, brand-agnostic recommendations to support more accurate and accessible diagnosis of Alzheimer’s using blood-based biomarker tests.” The standards, written by 11 clinicians and aided by public comments, will be revised as needed. The current draft covers the following tests: “plasma phosphorylated-tau (p-tau) and amyloid-beta (Aβ) tests measuring the following analytes: p-tau217, ratio of p-tau217 to non-p-tau217 ×100 (%p-tau217), p-tau181, p-tau231, and ratio of Aβ42 to Aβ40.”
Key points:
For patients experiencing cognitive impairment who are being observed in specialized care for memory disorders: 1) blood-based biomarker tests with ≥90% sensitivity and ≥75% specificity can serve as a tool for diagnosing Alzheimer’s, but should be followed up with another methodology if a positive result is shown. 2) blood-based biomarker tests with ≥90% and specificity can replace PET amyloid imaging or CSF Alzheimer’s biomarker testing.
Alzheimer’s Association warns that “there is significant variability in diagnostic test accuracy and many commercially available BBM tests do not meet these thresholds.”
Blood-based biomarker tests should not replace clinical assessment.
