Tau in dementia with Lewy bodies

Objective: Neurofibrillary tangles are present in a proportion of people with dementia with Lewy bodies and may be associated with worse cognition. Recent advances in biomarkers for Alzheimer's disease include second-generation tau positron emission tomography as well as the detection of phosphorylated tau at threonine 181 (p-tau181) in plasma. This study aimed to investigate tau in people with dementia with Lewy bodies using a second-generation tau positron emission tomography tracer as well as plasma p-tau181. Methods: Twenty-seven participants (mean age 74.7 +/- 5.5) with clinically diagnosed probable dementia with Lewy bodies underwent comprehensive clinical assessment and positron emission tomography imaging (F-18-MK6240 and F-18-NAV4694). Plasma p-tau181 levels were measured using Simoa technology. Results: Five dementia with Lewy bodies participants (18.5%) had an abnormal tau positron emission tomography (increased tau uptake in the temporal meta-region-of-interest). Higher plasma p-tau181 concentrations correlated with higher tau deposition in the temporal region (rho = 0.46, 95% confidence interval = [0.10, 0.72]) and classified abnormal tau positron emission tomography in dementia with Lewy bodies with an area under the curve of 0.95 (95% confidence interval = [0.86, 0.99]). Plasma p-tau181 also correlated positively with cortical amyloid-beta binding (rho = 0.68, 95% confidence interval = [0.40, 0.84]) and classified abnormal amyloid-beta positron emission tomography in dementia with Lewy bodies with an area under the curve of 0.91 (95% confidence interval = [0.79, 0.99]). There was no association found between tau deposition and any of the clinical variables. Conclusions: Tau is a common co-pathology in dementia with Lewy bodies. Plasma p-tau181 correlated with abnormal tau and amyloid-beta positron emission tomography and may potentially be used as a marker to identify co-morbid Alzheimer's disease-related pathology in dementia with Lewy bodies. The clinical implications of tau in dementia with Lewy bodies need to be further evaluated in larger longitudinal studies.

Automated summary

This study found that tau protein is commonly present in individuals with dementia with Lewy bodies and may be associated with worse cognition. The levels of plasma p-tau181 correlated with tau deposition and amyloid-beta binding, suggesting its potential as a marker for identifying co-morbid Alzheimer's disease-related pathology in dementia with Lewy bodies. Further research is needed to evaluate the clinical implications of tau in larger longitudinal studies.