P2‐224: DECREASED LEVELS OF CSF ABETA40 IN DEMENTIA WITH LEWY BODIES

Abstract

Amyloid beta (Abeta) deposition is commonly observed in the brains of dementia with Lewy bodies (DLB), and may be related to mental decline. We previously reported that levels of CSF Abeta42 were decreased in DLB patients. Here, we have focused on CSF levels of Abeta40. We measured the levels of CSF Abeta40 in DLB patients and compared with those in Alzheimer's disease (AD) patients. The subjects of this study consisted of clinically diagnosed 17 patients with DLB (6 females, 11 males, age 78.9±6.7 years), and 34 patients with AD (24 females, 10 males, age 75.4±8.2 years). The clinical diagnosis was made based on the DLB diagnostic criteria (McKeith IG. et al. Neurology, 89(1): 88–100, 2017). The CSF samples were obtained by lumbar puncture after informed consent was obtained. The CSF levels of Abeta40 and Abeta42 were measured by ELISA (Fujirebio, Belgium) according to the manufacturer's protocol. We compared the levels of CSF Abeta40 and Abeta42 between the DLB and AD groups. The CSF levels of Abeta40 (pg/ml) were 3337.9±1859.4 in the DLB group, and 5497.7±1886.4 in the AD group (normal standard levels :>4500pg/ml). The CSF levels of Abeta42 (pg/ml) were 361.8±147.3 in the DLB group, and 266.6±125.5 in the AD group (normal standard levels :>500pg/ml). The CSF levels of Abeta40 were significantly lower in the DLB group than those in the AD group (p<0.001, t-test), whereas the CSF levels of Abeta42 were significantly lower in the AD group than those in the DLB group (p<0.05, t-test) The CSF levels of Abeta40 were significantly lower in the DLB group than those in the AD group. Assessment of CSF Abeta40 levels may distinguish DLB from AD.