The spatial pattern of β‐amyloid (Aβ) deposits in Alzheimer's disease patients is related to apolipoprotein genotype

Abstract

The spatial patterns of the diffuse, primitive and classic β-amyloid (Aβ) deposits were studied in the frontal and temporal cortex in cases of Alzheimer's disease (AD) expressing different apolipoprotein (Apo E) genotypes. No significant differences in the density of the three Aβ deposit subtypes were observed in individuals expressed genotypes ϵ2/3 and ϵ3/3 compared with those expressing ϵ3/4 and ϵ4/4. In all patients, Aβ deposit subtypes occurred in the tissue in clusters. Chi-square contingency analyses of the data suggested that the cluster size of the diffuse and classic Aβ deposits was unrelated to Apo E genotype. However, the primitive (‘neuritic’) type Aβ deposits occurred more frequently in smaller, denser clusters in individuals expressing genotypes ϵ3/4 and ϵ4/4 compared with those expressing ϵ2/3 and ϵ3/3. Hence, the presence of the ϵ4 allele may be associated with a more specific pattern of neuronal degeneration in the frontal and temporal cortex in AD.