A new guideline from the Alzheimer’s Association sets strict criteria for blood tests to diagnose Alzheimer’s disease, replacing expensive brain scans and invasive CSF sampling. To be used clinically, blood tests must meet sensitivity and specificity thresholds of at least 90% and 75%, or 90% and 90%. These tests will initially screen patients with a negative result ruling out the condition, while positive results lead to additional testing.
Currently available tests include plasma phosphorylated tau (p-tau) proteins, amyloid-beta species, and various ratios. However, many commercially available tests do not meet these thresholds due to limited regulatory oversight.
The guideline evaluated 31 tests, with only a handful meeting accuracy standards for triage and one test being deemed suitable for replacing PET scans and CSF testing. Panel members noted significant limitations in study data, including missing cognitive unimpaired individuals and failing to consider false positives and negatives.
Despite these concerns, the guideline provides a rigorous framework for clinicians to use blood biomarker tests confidently. Adoption of these recommendations is expected to lead to quicker diagnoses and better outcomes for patients affected by Alzheimer’s disease.
Source: https://www.medpagetoday.com/meetingcoverage/aaic/116722