Why Most Blood Tests for Alzheimer’s Are Inconclusive and What to Use Instead
Blood tests have advanced the search for Alzheimer’s answers, but most fail to deliver a clear diagnosis. While they measure biomarkers like beta-amyloid and pTau, they often fall short in real-world clinical settings, where the challenge is distinguishing Alzheimer’s from other types of dementia.
The Core Problem: False Confidence
Most blood tests are validated by comparing people with Alzheimer’s to healthy individuals. But this doesn’t reflect the true diagnostic challenge in practice - differentiating Alzheimer’s from conditions like frontotemporal dementia, Lewy body dementia, or vascular cognitive impairment.
In studies where blood tests were challenged with real patients suffering from non-Alzheimer’s dementias, accuracy dropped dramatically. For example, plasma pTau181 showed only 62–67% specificity when compared against frontotemporal dementia.
Why This Matters
An Alzheimer’s misdiagnosis can lead to:
- Unnecessary or dangerous treatments, including anti-amyloid therapies with high risk of ARIA (brain swelling or bleeding)
- Missed treatment opportunities for reversible causes like thyroid issues, depression, or medication side effects
- Emotional and financial harm for patients and families who may make irreversible decisions based on unclear test results
The Better Approach: DISCERN™
DISCERN™ is different. It’s a morphometric imaging test based on skin biopsy and is validated against autopsy-confirmed cases - the gold standard in diagnosis.
Unlike blood tests that only measure indirect risk markers, DISCERN™ detects actual Alzheimer’s pathology in the patient’s cells and delivers binary (yes or no) diagnostic clarity with over 95% sensitivity and specificity.
Final Thoughts
Alzheimer’s diagnosis isn’t just about detecting brain changes - it’s about doing it accurately. Blood-based tests provide clues. DISCERN™ offers answers.