Plasma sphingolipid changes with autopsy-confirmed Lewy body or Alzheimer's pathology

INTRODUCTION The clinical and pathological phenotypes of Dementia with Lewy Bodies (DLB) and Alzheimer's disease (AD) often overlap. We examined whether plasma lipids differed among individuals with autopsy-confirmed Lewy Body pathology or AD pathology. METHODS We identified four groups with available plasma two years prior to death: high (n=12) and intermediate likelihood DLB (n=14) based on the third report of the DLB consortium; dementia with Alzheimer's pathology (AD; n=18); and cognitively normal with normal aging pathology (n=21). Lipids were measured using ESI/MS/MS. RESULTS There were overall group differences in plasma ceramides C16:0, C18:1, C20:0 and C24:1 and monohexosylceramides C18:1 and C24:1. These lipids did not differ between the high likelihood DLB and AD groups, but both groups had higher levels than normals. Plasma fatty acid levels did not differ by group. DISCUSSION Plasma ceramides and monohexosylceramides are elevated in people with dementia with either high likelihood DLB or AD pathology.