Cerebrospinal Fluid Levels of β-Amyloid 40 and β-Amyloid 42 are Proportionately Decreased in Amyloid Positron-Emission Tomography Negative Idiopathic Normal-Pressure Hydrocephalus Patients.

Content Provider	Europe PMC
Author	Kim, Hyun Jae Lim, Tae Sung Lee, Sun Min Kim, Tae-Sung Kim, Youngbin An, Young-Sil Youn, Young Chul Park, Sun Ah Chang, Jaerak Moon, So Young
Copyright Year	2019
Abstract	Background and PurposeCerebrospinal fluid (CSF) biomarkers of Alzheimer's disease (AD) could be misleading in idiopathic normal-pressure hydrocephalus (iNPH). We therefore investigated the CSF biomarkers in 18F-florbetaben amyloid-negative positron-emission tomography (PET) [amyloid PET(−)] iNPH, amyloid-positive PET [amyloid PET(+)] AD, and cognitively normal (CN) subjects.MethodsTen amyloid PET(+) AD patients (56.7±5.6 years old, mean±standard deviation), 10 amyloid PET(−) iNPH patients (72.8±4.5 years old), and 8 CN subjects (61.2±6.5 years old) were included. We measured the levels of β-amyloid (Aβ)40, Aβ42, total tau (t-tau) protein, and phosphorylated tau (p-tau) protein in the CSF using enzyme-linked immunosorbent assays.ResultsThe level of Aβ42 and the Aβ42/Aβ40 ratio in the CSF were significantly lower in AD than in iNPH or CN subjects. The Aβ40 level did not differ significantly between AD and iNPH (p=1.000), but it did between AD and CN subjects (p=0.032). The levels of both t-tau and p-tau were higher in AD than in iNPH or CN subjects. The levels of Aβ42, Aβ40, t-tau, and p-tau were lower in iNPH than in CN subjects, but there was no significant difference after controlling for age.ConclusionsOur results suggest that the mechanism underlying low CSF Aβ levels differs between amyloid PET(−) iNPH and amyloid PET(+) AD subjects. The lower levels of all CSF biomarkers in iNPH patients might be due to reduced clearances from extracellular fluid and decreased brain metabolism of the periventricular zone in iNPH resulting from glymphatic dysfunction.
ISSN	17386586
Journal	Journal of Clinical Neurology (Seoul, Korea)
Volume Number	15
PubMed Central reference number	PMC6620439
Issue Number	3
PubMed reference number	31286708
e-ISSN	20055013
DOI	10.3988/jcn.2019.15.3.353
Language	English
Publisher	Korean Neurological Association
Publisher Date	2019-07-01
Access Restriction	Open
Rights License	This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Copyright © 2019 Korean Neurological Association
Subject Keyword	Alzheimer's disease biomarkers idiopathic normal pressure hydrocephalus amyloid positron-emission tomography cerebrospinal fluid
Content Type	Text
Resource Type	Article
Subject	Neurology Neurology (clinical)