Lancet correspondence documents amyloid-β pathology in blood transfusion recipients from donors with cerebral amyloid angiopathy

The correspondence details four cases where recipients developed cerebral amyloid angiopathy or related pathology years after receiving transfusions. Donor records showed subsequent CAA diagnoses. No alternative iatrogenic routes were identified in the index cases. Data remain limited to observational linkage without controlled cohort quantification.

Prior evidence from 2018 Nature and 2022 Acta Neuropathologica papers established iatrogenic amyloid-β transmission via cadaveric growth hormone and dural grafts. Blood products represent a higher-volume exposure route. Prion precedent shows blood can carry misfolded proteins at detectable titers, yet current donor deferral criteria omit amyloid markers.

Operational impact centers on blood safety protocols. No FDA or EMA guidance currently screens for amyloid-β seeds. If replication cohorts confirm transmission above background rates, leukoreduction or donor history filters become immediate candidates for evaluation.

Next steps require prospective recipient registries tracking CAA incidence against transfusion volume and donor status, with results expected within 24-36 months from ongoing European surveillance networks.