title: Cerebrospinal fluid levels of IL-6 are decreased and correlate with cognitive status in DLB patients.
abstract: BACKGROUND
  Inflammatory processes have previously been shown to influence cognition and progression of dementia. An involvement of interleukin (IL)-6 has in particular been suggested as altered levels of IL-6 in cerebrospinal fluid (CSF) have been found in patients with Alzheimer's disease (AD). Also, an association between cognitive decline and levels of IL-6 in CSF have been reported. The aim of the present study was to investigate whether patients clinically diagnosed with dementia with Lewy bodies (DLB) display altered CSF IL-6 levels in comparison with patients with AD and control subjects without dementia and whether the IL-6 levels are correlated with cognitive status and biomarkers for AD and synucleinopathy.
  
  
  METHODS
  To analyse CSF of patients with AD (n = 45), patients with DLB (n = 29) and control subjects without dementia (n = 36), we used immunoassays to measure levels of IL-6 (multiplex electrochemiluminescence); AD markers phosphorylated tau, total tau and amyloid-β1-42 (enzyme-linked immunosorbent assay [ELISA]); and α-synuclein (ELISA). Cognitive status was evaluated using the Mini Mental State Examination (MMSE).
  
  
  RESULTS
  Our analysis showed significantly lower levels of IL-6 in CSF from patients with DLB than in CSF from patients with AD and control subjects without dementia. The IL-6 levels were also negatively correlated with MMSE and positively correlated with α-synuclein CSF levels.
  
  
  CONCLUSIONS
  Our findings support previous studies by demonstrating a link between inflammatory processes and dementia progression and further strengthen the hypothesis that IL-6 is involved in dementia pathology and cognitive decline.
authors.affiliation: Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Faculty of Medicine, Lund University, Wallenberg Laboratory, floor 2, Inga-Marie Nilssons gata 53, 205 02, Malmö, Sweden. malin.wennstrom@med.lu.se.
authors.forename: Malin
authors.initials: M
authors.lastname: Wennström
authors.affiliation: Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Faculty of Medicine, Lund University, Wallenberg Laboratory, floor 2, Inga-Marie Nilssons gata 53, 205 02, Malmö, Sweden. sara.hall@med.lu.se.
authors.forename: Sara
authors.initials: S
authors.lastname: Hall
authors.affiliation: Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Faculty of Medicine, Lund University, Wallenberg Laboratory, floor 2, Inga-Marie Nilssons gata 53, 205 02, Malmö, Sweden. Katarina.Nagga@skane.se.
authors.forename: Katarina
authors.initials: K
authors.lastname: Nägga
authors.affiliation: Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Faculty of Medicine, Lund University, Wallenberg Laboratory, floor 2, Inga-Marie Nilssons gata 53, 205 02, Malmö, Sweden. Elisabet.Londos@skane.se.
authors.forename: Elisabet
authors.initials: E
authors.lastname: Londos
authors.affiliation: Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Faculty of Medicine, Lund University, Wallenberg Laboratory, floor 2, Inga-Marie Nilssons gata 53, 205 02, Malmö, Sweden. Lennart.Minthon@skane.se.
authors.forename: Lennart
authors.initials: L
authors.lastname: Minthon
authors.affiliation: Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Faculty of Medicine, Lund University, Wallenberg Laboratory, floor 2, Inga-Marie Nilssons gata 53, 205 02, Malmö, Sweden. oskar.hansson@med.lu.se.
authors.forename: Oskar
authors.initials: O
authors.lastname: Hansson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000134:cerebrospinal fluid; D003071:Cognition / Q000502:physiology; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000134:cerebrospinal fluid*; D020961:Lewy Body Disease / Q000134:cerebrospinal fluid* / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D051844:alpha-Synuclein / Q000134:cerebrospinal fluid
chemical_list: D015415:Biomarkers; C508600:IL6 protein, human; D015850:Interleukin-6; C497604:SNCA protein, human; D051844:alpha-Synuclein