30-Second Takeaway
- Plasma p-tau217 and GFAP in SCD track amyloid status, cognitive decline, and progression toward MCI or dementia.
- Meta-analysis supports plasma p-tau217 as a robust classifier of amyloid positivity in cognitively normal older adults.
- CSF α-syn seed amplification assays and NfL outperform other CSF markers for differentiating PD from atypical parkinsonian syndromes.
- Cerebral microbleeds attenuate the association between tau burden and subsequent cognitive decline and atrophy, highlighting parallel CSVD-driven pathways.
- Physical and cognitive activity show modestly favorable AD biomarker trajectories and lower incident AD risk across genetic strata.
Week ending December 6, 2025
Preclinical AD biomarkers, CSF markers in parkinsonism, and vascular–neurodegenerative interactions
Plasma p-tau217 and GFAP track amyloid-positive SCD and predict progression
In this memory-clinic SCD cohort (n=298, mean age ~62), 80 individuals were amyloid-positive by PET or CSF. Baseline plasma pTau217, GFAP, and NfL were higher, and their slopes steeper, in amyloid-positive vs amyloid-negative SCD participants. Longitudinal increases in pTau217 and GFAP were associated with worse trajectories across all cognitive domains. Decreasing Aβ42/40 and increasing NfL were linked to decline in global cognition, language, and executive function. Steeper pTau217 slope raised the risk of progression from SCD to MCI or dementia, supporting its use for preclinical AD monitoring.
Meta-analysis: plasma p-tau217 robustly identifies amyloid-positive, cognitively normal adults
This meta-analysis pooled 18 studies including 7,834 cognitively unimpaired older adults with amyloid PET or CSF classification. Plasma p-tau217 showed a large standardized mean difference between amyloid-positive and amyloid-negative groups (Hedges g 1.50). Classification accuracy for amyloid positivity was high, with pooled AUC 0.87 (95% CI 0.85-0.90). Between-study heterogeneity and publication bias were explored but did not negate the overall strong association. Findings support plasma p-tau217 as a clinically useful blood test to detect preclinical AD pathology in research and potentially memory-clinic settings.
CSF α-syn SAA and NfL lead for PD vs atypical parkinsonism diagnosis
This network meta-analysis synthesized 70 studies including 4,925 PD patients, 698 MSA, 177 PSP, 78 DLB, and 3,072 controls. CSF α-syn seed amplification assays showed pooled sensitivity 0.91 and specificity 0.95 for distinguishing PD from healthy or non-neurologic controls. CSF NfL achieved AUC 0.91 for separating PD from MSA and showed similarly high accuracy for differentiating PD from PSP. Only CSF Aβ1-42 was evaluated for PD vs DLB and demonstrated limited diagnostic performance with modest sensitivity and specificity. Ranking analyses identified α-syn SAA as the top CSF biomarker overall, supporting its consideration as a first-line diagnostic tool in parkinsonism workups.
References
Numbered in order of appearance. Click any reference to view details.
Additional Reads
Optional additional studies from this edition.