Amyloid-related imaging abnormalities in antiamyloid therapy for Alzheimer's disease: a narrative review

Abstract

Summary Antiamyloid therapies have sparked a new hope for a potential disease-modifying therapy for Alzheimer's disease. Antiamyloid therapy targets amyloid-beta, which is a key feature of the disease. However, adverse effects such as amyloid-related imaging abnormalities (ARIA) have raised significant concerns about the safety of these therapies. ARIA, which includes vasogenic edema (ARIA-E) and microhemorrhages or hemosiderosis (ARIA-H), is a common adverse effect to antiamyloid therapies. Patient-related risk factors for ARIA include carrying the APOE-ε4 allele and cerebral amyloid angiopathy (CAA). Drug-related risk factors for ARIA include higher drug doses, early initiation of treatment, and concomitant use of antithrombotic medications, all of which increase the likelihood of vascular disruptions. Management of ARIA involves regular MRI monitoring and possibly temporary or permanent discontinuation of therapy if adverse effects develop during therapy. A gradual dose titration is recommended to minimize the risk of ARIA. Although antiamyloid therapies have demonstrated efficacy in reducing amyloid burden, the clinical benefit remains at best modest and must be weighed against the risks of developing adverse effects such as ARIA.