A cerebrospinal fluid synaptic protein biomarker for prediction of cognitive resilience versus decline in Alzheimer's disease.
Level 3 - non-randomized controlled study
Prospective multi-cohort observational prognostic study.
PubMed 40164724 · doi:10.1038/s41591-025-03565-2
What was done
Cerebrospinal fluid (CSF) proteomics was performed on 3,397 individuals across six prospective Alzheimer's disease (AD) cohorts to identify novel markers of cognitive impairment. Using machine learning, investigators derived a synaptic protein ratio (YWHAG:NPTX2) and evaluated its ability to explain cognitive variance and predict progression over up to 15 years of follow-up in amyloid-positive and phosphorylated tau-positive (A+T1+) individuals, adjusting for age, sex, APOE4 status, and established CSF and PET biomarkers. A related plasma proteomic signature was also evaluated in 13,401 samples.
What was found
The CSF YWHAG:NPTX2 ratio explained 27% of the variance in cognitive impairment beyond CSF pTau181:Aβ42, 11% beyond tau PET, and 28% beyond CSF neurofilament light, GAP43, and neurogranin in A+T1+ individuals. Elevated ratios were detected 20 years before estimated symptom onset in autosomal dominant AD mutation carriers. In longitudinal analysis, each standard deviation increase in CSF YWHAG:NPTX2 was associated with progression from cognitively normal to mild cognitive impairment (hazard ratio = 3.0, P = 7.0 × 10⁻⁴) and from mild cognitive impairment to dementia (hazard ratio = 2.2, P = 8.2 × 10⁻¹⁶) in A+T1+ individuals.
Why it matters
Amyloid and tau biomarkers explain only a fraction of the variance in cognitive decline among AD patients. This synaptic ratio provides independent prognostic value for tracking cognitive resilience versus deterioration and reinforces synapse dysfunction as an important driver and potential target in AD.
Limits
The primary findings require invasive lumbar puncture for CSF collection; the less-invasive plasma proteomic signature only partly recapitulated CSF results. As an observational study, it cannot establish direct causality. The abstract does not report the racial or ethnic composition of the cohorts, missing data rates, or analytical validity across different laboratory assay platforms.