Cerebrospinal fluid levels of IL-6 are decreased and correlate with cognitive status in DLB patients.

Abstract

INTRODUCTION:

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: Malin Wennström, Sara Hall, Katarina Nägga, Elisabet Londos, Lennart Minthon, Oskar Hansson
• Journal: Alzheimer's research & therapy (Alzheimers Res Ther) Vol. 7 Issue 1 Pg. 63 (Oct 05 2015) ISSN: 1758-9193 [Print] England
• PMID: 26434635 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Biomarkers
• IL6 protein, human
• Interleukin-6
• SNCA protein, human
• alpha-Synuclein

Topics

• Adult
• Aged
• Aged, 80 and over
• Biomarkers (cerebrospinal fluid)
• Cognition (physiology)
• Female
• Humans
• Interleukin-6 (cerebrospinal fluid)
• Lewy Body Disease (cerebrospinal fluid, psychology)
• Male
• Middle Aged
• Neuropsychological Tests
• alpha-Synuclein (cerebrospinal fluid)