Fig. 5.

Anti-amyloid-β peptide reactivity in the anterior olfactory nucleus. A Example of immunohistochemical staining for amyloid-β peptide in human olfactory bulb, concentrated in the AON, from a person with Alzheimer disease [case #46]. Scale bar represents 100 µM. B Representative images of semi-quantitative scoring of pathology, ranging from 0 to 5, in the AON. Scale bar represents 50 µM. C Percentage of cases in each group that have a pathology score of 1 or more. D Correlation between age and amyloid-β peptide scores in the control (HCO and NCO) and COVID19 + groups. Subject highlighted in blue is suspected to have Alzheimer disease (AD) based on neuropathological findings in the temporal lobes. E Distribution of pathology score for each group. Filled maroon circle (in D, E) indicates a control subject with amyloid-β-related angiitis; filled blue square indicates COVID19 + case suspected of having AD. Significance was determined using Kruskal–Wallis test with Dunn's post-hoc, where ** indicates p ≤ 0.01. Abbreviations for disease groups as in Fig. 1