title: Levels of cerebrospinal fluid α-synuclein oligomers are increased in Parkinson's disease with dementia and dementia with Lewy bodies compared to Alzheimer's disease.
abstract: BACKGROUND
  The objective was to study whether α-synuclein oligomers are altered in the cerebrospinal fluid (CSF) of patients with dementia, including Parkinson disease with dementia (PDD), dementia with Lewy bodies (DLB), and Alzheimer disease (AD), compared with age-matched controls.
  
  
  METHODS
  In total, 247 CSF samples were assessed in this study, including 71 patients with DLB, 30 patients with PDD, 48 patients with AD, and 98 healthy age-matched controls. Both total and oligomeric α-synuclein levels were evaluated by using well-established immunoassays.
  
  
  RESULTS
  The levels of α-synuclein oligomers in the CSF were increased in patients with PDD compared with the controls (P < 0.05), but not in patients with DLB compared with controls. Interestingly, the levels of α-synuclein oligomers in the CSF were also significantly higher in patients with PDD (P < 0.01) and DLB (P < 0.05) compared with patients with AD. The levels of CSF α-synuclein oligomers and the ratio of oligomeric/total-α-synuclein could distinguish DLB or PDD patients from AD patients, with areas under the curves (AUCs) of 0.64 and 0.75, respectively. In addition, total-α-synuclein alone could distinguish DLB or PDD patients from AD patients, with an AUC of 0.80.
  
  
  CONCLUSIONS
  The levels of α-synuclein oligomers were increased in the CSF from α-synucleinopathy patients with dementia compared with AD cases.
authors.affiliation: Department of Clinical Sciences, Lund University, Lund, Sweden ; Memory clinic, Skåne University Hospital, Lund, Sweden.
authors.forename: Oskar
authors.initials: O
authors.lastname: Hansson
authors.affiliation: Department of Clinical Sciences, Lund University, Lund, Sweden ; Neurology clinic, Skåne University Hospital, Lund, Sweden.
authors.forename: Sara
authors.initials: S
authors.lastname: Hall
authors.affiliation: Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
authors.forename: Annika
authors.initials: A
authors.lastname: Ohrfelt
authors.affiliation: Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
authors.forename: Henrik
authors.initials: H
authors.lastname: Zetterberg
authors.affiliation: Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy at University of Gothenburg, Gothenburg, Sweden.
authors.forename: Kaj
authors.initials: K
authors.lastname: Blennow
authors.affiliation: Department of Clinical Sciences, Lund University, Lund, Sweden.
authors.forename: Lennart
authors.initials: L
authors.lastname: Minthon
authors.affiliation: Department of Clinical Sciences, Lund University, Lund, Sweden.
authors.forename: Katarina
authors.initials: K
authors.lastname: Nägga
authors.affiliation: Department of Clinical Sciences, Lund University, Lund, Sweden.
authors.forename: Elisabet
authors.initials: E
authors.lastname: Londos
authors.affiliation: Department of Biochemistry, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates.
authors.forename: Shiji
authors.initials: S
authors.lastname: Varghese
authors.affiliation: Department of Biochemistry, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates.
authors.forename: Nour K
authors.initials: NK
authors.lastname: Majbour
authors.affiliation: Department of Anatomy, Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Abdulmonem
authors.initials: A
authors.lastname: Al-Hayani
authors.affiliation: Department of Biochemistry, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates ; Faculty of Medicine, King Abdulaziz University, Jeddah, Saudi Arabia.
authors.forename: Omar Ma
authors.initials: OM
authors.lastname: El-Agnaf