CSF levels of the synaptic marker Cyclase‐associated protein CAP2 in Alzheimer disease across clinical stages
Alessandro Padovani, Monica DiLuca, Elena Marcello, Andrea Pilotto, Barbara Borroni- Psychiatry and Mental health
- Cellular and Molecular Neuroscience
- Geriatrics and Gerontology
- Neurology (clinical)
- Developmental Neuroscience
- Health Policy
- Epidemiology
Abstract
Background
Synaptic dysfunction represent a key event in cognitive decline in Alzheimer disease. There is evidence that Cyclase‐associated protein 2 (CAP2) is involved in synaptic plasticity in AD models but its role in clinical setting has never extensively assessed. Aim of this study was to evaluate CAP2 levels in cerebrospinal fluids of AD and other neurodegenerative diseases and their relationship with amyloid and tau related biomarkers.
Method
one‐hundred ten AD patients (prodromal AD n = 70; mild to moderate AD n = 40), 20 Lewy Body Dementia (LBD), 20 frontotemporal dementia (FTD) and 40 healthy controls (HC) were investigated and clinically assessed following a standardized neurological and cognitive behavioral assessment. All subjects underwent CSF analyses for h‐tau, p‐tau and Aß42 (Lumipulse) while CAP2 levels were assessed by using standard ELISA. Between‐groups differences and correlations between CSF biomarkers were evaluated using non‐parametric comparisons and partial correlation analyses adjusted for the effect of age, sex and disease duration.
Result
AD patients across severity stages showed higher CAP2 levels compared to controls and non‐AD patients (p = 0.001). CAP2 levels did not correlate with disease severity and were independent of APOE genotype. In AD patients, CAP2 levels showed a positive correlation with t‐tau and p‐tau (p<0.001).
Conclusion
CSF levels of CAP2 were significantly increased in AD patients and correlated with t‐tau and p‐tau independently of amyloid pathology. Altogether, these findings support the hypothesis that AD is specifically associated with synaptic dysfunction since early stages and that amyloid‐related synaptic changes parallels tau‐related axonal degeneration.