Blood Test for Alzheimer’s in Reach
nytimes.com
nytimes.com
> Question What is the discriminative accuracy of plasma phospho-tau217 (P-tau217) for differentiating Alzheimer disease from other neurodegenerative disorders?
> Findings In this cross-sectional study that included 1402 participants from 3 selected cohorts, plasma P-tau217 discriminated Alzheimer disease from other neurodegenerative diseases (area under the receiver operating characteristic curve of 0.89 in a neuropathologically defined cohort and 0.96 in a clinically defined cohort), with performance that was significantly better than established Alzheimer disease plasma- and MRI-based biomarkers but not significantly different from key CSF- or PET-based biomarkers.
> Meaning Although plasma P-tau217 was able to discriminate Alzheimer disease from other neurodegenerative diseases, further research is needed to validate the findings in unselected and diverse populations, optimize the assay, and determine its potential role in clinical care.
But the theory is that b/c we can't properly differentiate between patients with Alzheimer's Dementia and those with other forms of dementia (such as Vascular Dementia), that any clinical trial could be pointless if a statistically significant number of patients have some other dementia instead of Alzheimer's Dementia. The coolest thing about a real quantitative test is the ability to vet patients in a clinical trial. In the last 20 years, literally HUNDREDS of interventions have gone to trial for Alzheimer's, but none have passed. Imagine if one of those interventions already was the cure, but we didn't know b/c the data was skewed by other forms of dementia patients!!!
So the first step in getting a treatment for Alzheimer's is to know if the patients has Alzheimer's :)