The load and distribution of β-amyloid in brain tissue of patients with Alzheimer's disease

Recent findings have underlined the significance of beta -amyloid protein (beta A4) in the etiology of Alzheimer's disease (AD). In 60 patients with AD, the amount of beta A4 deposition, estimated applying immunohistochemical techniques, was shown to be significantly influenced by apolipoprotein E (ApoE) genotype (epsilon4/epsilon4 >epsilon4/x > x/x), by the age at onset (presenile > senile), by the age at death (younger > older patients) and by the duration of the disease (long > short). Morphometric analysis revealed that the beta A4 load was highest in the superficial layer of the cortex and a significant influence on the vertical distribution was seen in females but not in males, in familial but not in sporadic cases and in senile but not in presenile cases. Our findings indicate that not only the load but also the vertical distribution of beta A4 within cortex is influenced by risk factors such as ApoE genotype and gender.