Spatial correlations between β-amyloid (Aβ) deposits and blood vessels in familial Alzheimer's disease

In sporadic Alzheimer's disease (SAD), the classic ('dense-cored') β-amyloid (Aβ) deposits are aggregated around the larger blood vessels in the upper laminae of the cerebral cortex. To determine whether a similar relationship exists in familial AD (FAD), the spatial correlations between the diffuse, primitive, and classic b-amyloid (Aβ deposits and blood vessels were studied in ten FAD cases including cases linked to amyloid precursor protein (APP) and presenilin (PSEN) gene mutations and expressing apolipoprotein E (apo E) allele E4. Sections of frontal cortex were immunolabelled with antibodies against Aβ and with collagen IV to reveal the Aβ deposits and blood vessel profiles. In the FAD cases as a whole, Aβdeposits were distributed in clusters. There was a positive spatial correlation between the clusters of the diffuse Aβdeposits and the larger (>10 μm) and smaller diameter (<10 μm) blood vessels in one and three cases respectively. The primitive Aβ deposits were spatially correlated with larger and smaller blood vessels each in four cases and the classic deposits in three and four cases respectively. Apo E genotype of the patient did not influence spatial correlation with blood vessels. Hence, spatial correlations between the classic deposits and larger diameter blood vessels were significantly less frequent in FAD compared with SAD. It was concluded that both Aβ deposit morphology and AD subtype determine spatial correlations with blood vessels in AD.