Direct quantification of CSF alpha-synuclein by ELISA and first cross-sectional study in patients with neurodegeneration.
Because accumulation of alpha-synuclein (alphaS) in the brain is a hallmark of Parkinson disease (PD) and related disorders, we examined its occurrence in human cerebrospinal fluid (CSF). Following affinity enrichment and trypsin digestion of CSF collected from a neurologically healthy donor, we identified several alphaS-derived peptides by mass spectrometry. The concentration of alphaS amounted to <0.001% of the CSF proteome. We then built, validated and optimized a sandwich-type, enzyme-linked immunoadsorbent assay (ELISA) to measure total alphaS levels in unconcentrated CSF. In a cross-sectional study of 100 living donors, we examined cell-free CSF samples from subjects clinically diagnosed with advanced PD, dementia with Lewy bodies (DLB), Alzheimer disease (AD), and a group of non-neurodegenerative disease controls (NCO). In these four groups the CSF alphaS concentrations ranged from 0.8 to 16.2 pg/microl. Mean CSF alphaS values were lower in donors with a primary synucleinopathy (PD, DLB: n=57) than in the other two groups (AD, NCO: n=35; p=0.025). By contrast, living Creutzfeldt-Jakob disease patients showed markedly elevated CSF alphaS levels (n=8; mean, 300 pg/microl; p<0.001). Our results unequivocally confirm the presence of alphaS in adult human CSF. In a first feasibility study employing a novel ELISA, we found relatively low CSF alphaS concentrations in subjects with parkinsonism linked to synucleinopathy, PD and DLB. In definite prion disease cases, we recorded a marked rise in total CSF alphaS resulting from rapid cell death. Our results will likely aid future biomarker explorations in neurodegenerative conditions and facilitate target validation studies.
Mollenhauer
Brit
B
Center for Neurologic Diseases, Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
Cullen
Valerie
V
Kahn
Ilana
I
Krastins
Bryan
B
Outeiro
Tiago F
TF
Pepivani
Imelda
I
Ng
Juliana
J
Schulz-Schaeffer
Walter
W
Kretzschmar
Hans A
HA
McLean
Pamela J
PJ
Trenkwalder
Claudia
C
Sarracino
David A
DA
Vonsattel
Jean-Paul
JP
Locascio
Joseph J
JJ
El-Agnaf
Omar M A
OM
Schlossmacher
Michael G
MG
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D000818:Animals; D015415:Biomarkers / Q000134:cerebrospinal fluid; D002478:Cells, Cultured; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000592:standards; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008875:Middle Aged; D008969:Molecular Sequence Data; D009410:Nerve Degeneration / Q000134:cerebrospinal fluid* / Q000235:genetics / Q000473:pathology; D051381:Rats; D051844:alpha-Synuclein / Q000134:cerebrospinal fluid* / Q000235:genetics
D015415:Biomarkers; D051844:alpha-Synuclein