Background: The apolipoprotein E (Apo E) epsilon4 allele has been associated with parietal metabolic abnormalities and asymmetries in asymptomatic subjects at risk for Alzheimer disease (AD). However, previous research has shown minimal effect of the epsilon4 allele on regional cerebral blood flow (rCBF) and metabolism in patients with probable AD.
Objective: To determine whether the Apo E epsilon4 allele is associated with parietal rCBF abnormalities and asymmetries in patients with probable AD.
Patients And Methods: Thirty patients with AD with the epsilon4 allele (epsilon4+ AD), 22 patients with AD without the epsilon4 allele (epsilon4- AD), and 14 healthy control subjects underwent single-photon emission computed tomography (SPECT) scanning with 740 MBq technetium Tc 99m hexamethylpropyleneamine oxime. Ratios of parietal-unaffected regions and a left-right parietal asymmetry index were compared between both patient groups.
Results: The group with epsilon4- AD was younger (P = .005, Student t test) and had an earlier age of onset (P = .005) than the group with epsilon4+ AD. Analysis of covariance revealed no significant difference in the parietal rCBF ratio, controlling for age of onset and Mini-Mental State Examination score (F(1,48) = 0.06; P = .81). However, contrary to hypothesis, significantly greater parietal rCBF asymmetry was seen in patients with epsilon4- AD (mean +/- SD, 9.7% +/- 5.5%) than those with epsilon4+ AD (6.3% +/- 4.7%; F(1,50) = 5.89; P = .02; analysis of variance). When number of epsilon4 allele copies was considered, this effect appeared to accrue primarily from a difference between patients with 0 and with 2 epsilon4 allele copies. An exploratory analysis of multiple cortical structures suggested that this asymmetry extended to additional regions (superior temporal) and to combined association cortex.
Conclusions: Greater parietal rCBF asymmetry is involved in epsilon4- AD than in epsilon4+ AD. Lack of the epsilon4 allele may be associated with other (as yet undiscovered) genetic or environmental risk factors, which confer greater neuropathological asymmetry.
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http://dx.doi.org/10.1001/archneur.55.11.1460 | DOI Listing |
J Med Microbiol
January 2025
Departamento de Bioqumica e Imunologia, Instituto de Cincias Biolgicas, Universidade Federal de Minas Gerais.
Apolipoprotein E (ApoE), especially the ApoE4 isotype, is suggested to influence the severity of respiratory viral infections; however, this association is still unclear. The presence of allele ε4 impacts the development of flu-like syndromes. This study aimed to evaluate the impact of the Apo E4 isoform on the severity and duration of flu-like syndromes, including the coronavirus disease COVID-19.
View Article and Find Full Text PDFJAMA Netw Open
January 2025
Alzheimer Center Limburg, Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands.
Importance: Baseline cerebral microbleeds (CMBs) and APOE ε4 allele copy number are important risk factors for amyloid-related imaging abnormalities in patients with Alzheimer disease (AD) receiving therapies to lower amyloid-β plaque levels.
Objective: To provide prevalence estimates of any, no more than 4, or fewer than 2 CMBs in association with amyloid status, APOE ε4 copy number, and age.
Design, Setting, And Participants: This cross-sectional study used data included in the Amyloid Biomarker Study data pooling initiative (January 1, 2012, to the present [data collection is ongoing]).
Importance: "SuperAgers" are oldest-old adults (ages 80+) whose memory performance resembles that of adults in their 50s to mid-60s. Factors underlying their exemplary memory are underexplored in large, racially diverse cohorts.
Objective: To determine the frequency of genotypes in non-Hispanic Black and non-Hispanic White SuperAgers compared to middle-aged (ages 50-64), old (ages 65-79), and oldest-old (ages 80+) controls and Alzheimer's disease (AD) dementia cases.
J Gerontol B Psychol Sci Soc Sci
January 2025
Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, Maryland, USA.
Objectives: Loneliness is associated with an elevated risk of dementia. There is mixed evidence from imaging studies on whether loneliness is associated with neuropathology in dementia-free adults. This study tests whether loneliness is associated with plasma neurobiomarkers of amyloid (Aβ42/Aβ40), phosphorylated tau 181 (pTau181), neurofilament light chain (NfL), and glial fibrillary acidic protein (GFAP) and imaging measures of amyloid and tau.
View Article and Find Full Text PDFBrain
January 2025
Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Faculty of Medicine, Lund University, 22184 Lund, Sweden.
The APOE4 allele is the strongest genetic risk factor for sporadic Alzheimer's disease (AD). While APOE4 is strongly associated with amyloid-beta (Aβ), its relationship with tau accumulation is less understood. Studies evaluating the role of APOE4 on tau accumulation showed conflicting results, particularly regarding the independence of these associations from Aβ load.
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