Study links lecanemab-associated ARIA to clonal CD8⁺ T-cell expansion

kellis
Wed, 25 Mar 2026 09:02:05 +0100

In a study published recently in the journal Nature Communi-cations, researchers from the US examined lecanemab-associated Amyloid-related imaging abnormalities (ARIA). ARIA remain the main safety concern associated with anti-amyloid therapies for Alzheimer’s disease, but the biological mechanisms behind these events are still not well under-stood. In this study, the researchers identified a peripheral immune signature associated with ARIA, centred on coordi-nated changes in CD8⁺ T cells.The study used multi-omic profiling of peripheral blood from three people with ARIA and matched controls. The researchers found expansion of CD8⁺ effector memory and terminally differentiated T-cell subsets, with these cells showing clonal enrichment and transcriptional changes linked to cytotoxic activity and vascular trafficking. Metabolomic and transcription factor analyses also pointed to glycolytic reprogramming favouring short-lived effector function.Further modelling suggested stronger monocyte-to-T-cell signalling through antigen presentation, adhesion and chemokine pathways. Integration with a cerebrovascular atlas indicated that ARIA-associated terminally differentiated CD8⁺ T cells were transcriptionally primed for vascular engagement. The researchers concluded that ARIA may be associated with metabolic reprogramming, clonal CD8⁺ T-cell expansion and altered intercellular communication, though they stressed that these findings need validation in larger cohorts.The article has been published open access and can be read here:https://www.nature.com/articles/s41467-026-68921-3