ATN Cerebrospinal Fluid Biomarkers in Dementia with Lewy Bodies: Initial Results from the United States Dementia with Lewy Bodies Consortium

Abstract

AbstractBackgroundNeuropathological hallmarks of AD, amyloid plaques and neurofibrillary tangles, have been described in dementia with Lewy bodies (DLB). Less is known about changes in pre‐mortem cerebrospinal fluid (CSF) amyloid and tau biomarker status in DLB. CSF biomarkers for amyloid (A), tau (T), and neurodegeneration (N) can be utilized to define pre‐mortem pathological status. The overall aim of this investigation was to utilize the ATN research framework to characterize pre‐mortem AD‐related pathology longitudinally in a rigorously characterized cohort of DLB from the Dementia with Lewy Bodies Consortium (DLBC) study. Our hypothesis was that ATN biomarkers would identify DLB with coexistent AD and ATN status would remain the same after 12 months.MethodCerebrospinal fluid (CSF) samples from an AD/ADRD cohort were obtained from the Cleveland Alzheimer’s Disease Research Center (CADRC), Cleveland Clinic Lou Ruvo Center for Brain Health Aging and Neurodegenerative Disease Biobank (CBH‐biobank) and DLBC. CSF Aβ40, Aβ42, Aβ42/40 (A), p‐Tau181 (T), and t‐Tau (N), were evaluated. The cohort was subtyped by CSF ATN category and sub‐group of DLB cases were neuropathologically evaluated. A sub‐cohort of DLB cases had longitudinal data with an evaluation at baseline and 12 months later.ResultDLB patients who were positive for both CSF Aβ42/40 (A+) and p‐Tau181 (T+) remained positive from baseline to 12 months. In contrast, some DLB patients who were positive for CSF Aβ42/40 (A+), but negative for p‐Tau181 (T‐), changed from CSF Aβ42/40 positive to negative at 12 months (p‐value = 0.0153) in the A+T‐N‐ and A+T‐N+ group. Findings from a small DLB subgroup with post‐mortem neuropathologic analyses indicated that most of the cases that were p‐Tau181 positive (T+) also had high Braak stage.ConclusionThese findings suggest that DLB patients who are positive for CSF Aβ42/40 (A+), but negative for p‐Tau181 (T‐), may have CSF Aβ42/40 levels that can fluctuate over time. In the small DLB subgroup with post‐mortem neuropathologic analysis, there appeared to be a relationship between AD pathologic change and ATN findings that warrants further study in a larger autopsied cohort to fully understand the relationship between ATN status and underlying AD neuropathologic change in DLB.