👤 Susanne J van Veluw

Cerebral small vessel disease (CSVD) contributes to the development of Alzheimer's disease (AD) dementia and co-occurs with AD-associated proteinopathies. However, how sex modulates the interaction between CSVD and AD-associated proteinopathies in the medial temporal lobe (MTL) remains unclear. One hundred fifty-two autopsy cases from the Massachusetts Alzheimer's Disease Research Center were included. Deep-learning and semiquantitative scores were applied to MTL histological sections to obtain quantitative measures of proteinopathies and CSVD (cerebral amyloid angiopathy [CAA] and arteriolosclerosis). The effect of sex on AD-associated proteinopathies and the interaction between sex, CSVD, and apolipoprotein E (APOE) genotype were analyzed using linear mixed-effect models. In women, higher CAA burden was associated with lower amyloid beta (Aβ) plaques but higher tau tangles density. No interaction effect was found for arteriolosclerosis. Women <75 years of age carrying the APOE ε4 allele had higher Aβ plaque burden than ε4 non-carriers. Our results highlight the complex effect of sex on microvascular and AD-associated pathologies in the MTL. Show less

Lobar intracerebral haemorrhage (ICH) is associated with cerebral amyloid angiopathy (CAA) pathology. Uncertainty remains about the mechanisms leading from CAA to ICH. We investigated the distribution and characteristics of CAA, and its clinical and neuropathological associations. Participants underwent research autopsy in the Lothian IntraCerebral Haemorrhage, Pathology, Imaging and Neurological Outcome (LINCHPIN) study. Neuropathologists rated tissue for CAA using standardised consensus criteria, as well as non-amyloid small vessel disease, Thal phase, and Braak stage. We compared the presence, distribution, and severity of CAA among different brain regions, and in the lobe or hemisphere affected by lobar ICH to corresponding contralateral regions. We evaluated the diagnostic accuracy of Vonsattel CAA grade on a post-mortem cortical specimen (simulating surgical biopsy) versus the reference standard of moderate-to-severe parenchymal CAA at autopsy. Among 162 participants, parenchymal CAA, meningeal CAA, and CAA-associated vasculopathy were diffusely distributed among all cerebral lobes irrespective of the ICH location, but capillary CAA showed an occipital predominance. In lobar ICH, all CAA measures did not differ between the ICH lobe or hemisphere and the contralateral unaffected region. CAA measures did not increase with age, but they were higher in carriers of APOE ε2 or ε4 alleles and in individuals with higher Thal phase or Braak stage. Using a rule-out category of Vonsattel grade ≥ 1 to diagnose CAA on a simulated cortical biopsy achieved 100% sensitivity (95%CI 93.4-100), and a rule-in category of Vonsattel grade ≥ 2 had 79.5% specificity (95%CI 63.5-90.7) versus the reference standard. The distribution and severity of parenchymal CAA, meningeal CAA, and CAA-associated vasculopathy are diffuse regardless of ICH location, indicating the need to better understand the factors underlying bleeding in CAA-affected vessels. Show less