Aim: Longitudinal studies of dementia with Lewy bodies (DLB) are needed to understand disease course and the relevance of emerging blood biomarkers. We aimed to describe associations between longitudinal clinical outcomes and blood biomarkers in DLB.
Methods: Participants with DLB underwent standardised annual clinical evaluation including cognition and function, blood collection and amyloidβ neuroimaging up to three years. Plasma biomarkers related to neurodegeneration (neurofilament light (NfL)), Alzheimer’s disease (AD) (p-tau181) and inflammation (glial fibrillary acidic protein (GFAP), cytokines (IFN-γ, IL-1β, IL-6, IL-8, IL-10, TNF-α)) were analysed. Baseline characteristics were compared between those who remained community-dwelling and those who had died or entered a residential aged care facility (RACF) at study completion. Change in cognition and blood biomarkers was also estimated from baseline to 3 years using clustered quantile regression.
Results: Of the 28 participants (mean age 73.4+/-5.7 years, 24 male), 17 remained community-dwelling, 4 lived in a RACF and 7 had died at study completion. Death/RACF entry was associated with baseline older age, worse cognition, visual hallucinations and positive amyloidβ neuroimaging. Higher baseline levels of p-tau181, GFAP and IL-6, and lower IL-10, were detected in the death/RACF group, particularly at the upper quartile, with a trend towards higher NfL. Over 3 years we detected an increase for most participants in NfL, p-tau-181, GFAP, IL-6 and IL-8.
Conclusions: Death/RACF entry at 3 years was associated with neuropsychiatric symptoms, AD co-pathology (blood and imaging biomarkers) and blood biomarkers connected to neurodegeneration and a pro-inflammatory state (higher GFAP and IL-6, lower IL-10).