Aim: To compare blood biomarkers of neurodegeneration, inflammation and Alzheimer’s disease (AD) between patients with dementia with Lewy bodies (DLB) and controls. This will improve understanding of the utility of these emerging dementia biomarkers in DLB.
Methods: Participants with DLB and cognitively normal healthy controls (age and sex-matched) provided fasting blood samples to an observational Australian study. Plasma was analysed for biomarkers of neurodegeneration (neurofilament light (NfL)), AD (p-tau181) and inflammation (glial fibrillary acidic protein (GFAP), YKL-40, cytokines (TNF-α, IL-1β, IL-6, IL-8, IL-10, IFN-γ)). Quantile regression assessed differences between groups and receiver-operating characteristic analysis for area under the curve (AUC) assessed biomarker utility for discriminating DLB participants from controls.
Results: Fifty DLB participants (mean age 73.7+/-6.0 years, 82% male) and 20 controls (mean age 74.6+/-4.7 years, 80% male) were included. NfL levels were higher in the DLB group compared to controls (DLB median 18.1 [IQR 14.2-24.7] pg/mL vs controls 12.6 [10.7-16.4] pg/mL, p=0.033) and NfL was the most useful individual marker to discriminate between groups (AUC 0.704, 95% confidence interval 0.57-0.84). GFAP levels were significantly higher in the DLB group only at the upper quartile, and there was a trend towards increased p-tau181 and IL-10 in the DLB group.
Conclusions: Plasma NfL was higher in DLB participants compared to age and sex-matched healthy controls. There was a trend towards higher levels of biomarkers related to AD (p-tau181), astrocyte activation (GFAP) and the anti-inflammatory cytokine IL-10. The utility of these non-disease specific biomarkers in DLB requires further investigation.