Plasma butyrylcholinesterase activity: a possible biomarker for differential diagnosis between Alzheimer's disease and dementia with Lewy bodies?

Butyrylcholinesterase (BChE) is an enzyme encoded by BCHE gene, responsible for secondary hydrolysis of the acetylcholine. K and -116A BCHE variants were associated with decrease in plasma BChE activity, and their influence has been investigated in diseases with a cholinergic deficit such as Alzheimer's disease (AD) and dementia with Lewy bodies (DLB). In order to check the influence of BCHE genetic variants on enzymatic activity, all patients and controls were genotyped for K and -116A variants. We found lower plasma BChE activity in DLB patients compared to elderly controls and to AD independent of the presence of K or -116A variants. Our results suggest that the reduction of total plasma BChE activity is probably associated with a feedback mechanism and provides a future perspective of using this enzyme as a possible plasmatic marker for differential diagnosis between AD and DLB.