Anti‐Amyloid Immunotherapy for AD: A Potential Link between ARIA and Complement

Passive immunization against Aβ using 3D6-L amplified CAA-associated complement activation and altered expression of genes related to extracellular matrix degradation and vascular inflammation. The observed microhemorrhages appear to result from complement-mediated vascular inflammation induced by the binding of 3D6-L to vascular amyloid. These findings suggest potential biomarkers or targets for therapeutic interventions in the context of anti-Aβ immunization.