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CSF levels of SNAP-25 are increased early in Creutzfeldt-Jakob and Alzheimer’s disease
ISSN
0022-3050
Date Issued
2022
Author(s)
Halbgebauer, Steffen
Hengge, Sophie
Oeckl, Patrick
Abu Rumeileh, Samir
Anderl-Straub, Sarah
Lombardi, Jolina
Giese, Armin
Ludolph, Albert C
DOI
10.1136/jnnp-2021-328646
Abstract
Background
Synaptosomal-associated protein 25 (SNAP-25) in cerebrospinal fluid (CSF) is an emerging synaptic biomarker for the early diagnosis of Alzheimer’s disease (AD). However, comprehensive studies investigating the marker in Creutzfeldt-Jakob disease (CJD) and in the differential diagnosis of neurodegenerative diseases are still lacking.
Methods
We developed a novel, sensitive ELISA for the measurement of SNAP-25 in CSF. In total, we analysed 316 patients from 6 diagnostic groups comprising patients with AD (n=96), CJD (n=55), Parkinson’s disease spectrum (n=41), frontotemporal lobar degeneration (n=25) and amyotrophic lateral sclerosis (n=24) and non-neurodegenerative control patients (n=75). Using receiver operating characteristic curve analysis, we analysed the differential diagnostic potential and compared the results with core AD biomarkers.
Results
SNAP-25 CSF concentrations were elevated in AD and CJD (p<0.0001) but not in the other neurodegenerative diseases. Increased levels were observed already at early AD and CJD stages (p<0.0001). In CJD, SNAP-25 levels correlated negatively with survival time (r=−0.33 (95% CI −0.57 to −0.04, p=0.02). For the discrimination of AD from all other diseases except CJD, we observed a good diagnostic performance for CSF SNAP-25 (area under the curve (AUC) 0.85) which was further improved by applying the ratio with CSF amyloid-β 1–42 (AUC 0.95). For CJD, we could demonstrate a strong differential diagnostic potential against all other groups including AD (AUC 0.97).
Conclusion
Using the novel established CSF SNAP-25 ELISA, we here demonstrate the applicability of SNAP-25 as an early synaptic biomarker for both AD and CJD with a possible prognostic value in patients with CJD.
Synaptosomal-associated protein 25 (SNAP-25) in cerebrospinal fluid (CSF) is an emerging synaptic biomarker for the early diagnosis of Alzheimer’s disease (AD). However, comprehensive studies investigating the marker in Creutzfeldt-Jakob disease (CJD) and in the differential diagnosis of neurodegenerative diseases are still lacking.
Methods
We developed a novel, sensitive ELISA for the measurement of SNAP-25 in CSF. In total, we analysed 316 patients from 6 diagnostic groups comprising patients with AD (n=96), CJD (n=55), Parkinson’s disease spectrum (n=41), frontotemporal lobar degeneration (n=25) and amyotrophic lateral sclerosis (n=24) and non-neurodegenerative control patients (n=75). Using receiver operating characteristic curve analysis, we analysed the differential diagnostic potential and compared the results with core AD biomarkers.
Results
SNAP-25 CSF concentrations were elevated in AD and CJD (p<0.0001) but not in the other neurodegenerative diseases. Increased levels were observed already at early AD and CJD stages (p<0.0001). In CJD, SNAP-25 levels correlated negatively with survival time (r=−0.33 (95% CI −0.57 to −0.04, p=0.02). For the discrimination of AD from all other diseases except CJD, we observed a good diagnostic performance for CSF SNAP-25 (area under the curve (AUC) 0.85) which was further improved by applying the ratio with CSF amyloid-β 1–42 (AUC 0.95). For CJD, we could demonstrate a strong differential diagnostic potential against all other groups including AD (AUC 0.97).
Conclusion
Using the novel established CSF SNAP-25 ELISA, we here demonstrate the applicability of SNAP-25 as an early synaptic biomarker for both AD and CJD with a possible prognostic value in patients with CJD.