Amyloid-related imaging abnormalities in AβPP duplication carriers.

Immune response to vascular amyloid-β deposits leads to cerebral amyloid angiopathy related-inflammation (CAA-ri). Amyloid-related imaging abnormalities (ARIA) were initially reported during anti-amyloid trials and are associated with the APOE 4/4 genotype. We report the evolution of an AβPP duplication carrier with an APOE 3/3 genotype presenting ARIA-Effusion and then ARIA-Hemosiderin deposit, without anti-amyloid therapy, suggestive of a possible spontaneously resolutive CAA-ri (not neuropathologically proven). It suggests common mechanisms between ARIA and CAA-ri and raises questions about mechanisms of this acute episode without APOE risk factor. The high vascular amyloid burden, induced by AβPP duplication, might increase amyloid epitope presentation and lead to inflammatory process.