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

• Published in: Alzheimer's research & therapy Vol. 7; no. 1; p. 63
• Main Authors: Wennström, Malin, Hall, Sara, Nägga, Katarina, Londos, Elisabet, Minthon, Lennart, Hansson, Oskar
• Format: Journal Article
• Language: English
• Published: London BioMed Central 05.10.2015; BioMed Central Ltd
• Subjects: Adult; Advertising executives; Aged; Aged, 80 and over; alpha-Synuclein - cerebrospinal fluid; Alzheimer's disease; Analysis; Biomarkers - cerebrospinal fluid; Biomedical and Life Sciences; Biomedicine; Clinical Medicine; Cognition; Cognition - physiology; Development and progression; Enzyme-linked immunosorbent assay; Enzymes; Female; Genetic aspects; Geriatric Psychiatry; Geriatrics/Gerontology; Health aspects; Humans; Interleukin-6 - cerebrospinal fluid; Interleukins; Klinisk medicin; Lewy Body Disease - cerebrospinal fluid; Lewy Body Disease - psychology; Male; Measurement; Medical and Health Sciences; Medical research; Medicin och hälsovetenskap; Medicine, Experimental; Middle Aged; Neurologi; Neurology; Neuropsychological Tests; Neurosciences; Dementia With Lewy Body; Mini Mental State Examination; Multiple System Atrophy; Mini Mental State Examination Score; Dementia
• ISSN: 1758-9193; 1758-9193
• DOI: 10.1186/s13195-015-0145-y

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-β 1–42 (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.