Blood Transfusions May Carry Alzheimer's-Linked Protein, Review Warns
A Lancet review suggests that amyloid-beta proteins associated with Alzheimer's disease could potentially be transmitted through blood transfusions, though the risk remains undefined. The authors call for urgent research and accurate screening assays to inform public health decisions. The review follows a large Scandinavian study hinting at a transfusion-transmissible agent linked to intracerebral hemorrhage.
The review stems from a 2023 Scandinavian study of over one million transfusion recipients, which found a higher risk of spontaneous brain hemorrhage when donors later developed multiple such bleeds. The authors note that while this epidemiological link cannot confirm cerebral amyloid angiopathy, it aligns with the idea that misfolded amyloid-beta proteins might act like prions, seeding aggregation in new hosts. Earlier evidence includes transmissions via cadaver-derived growth hormone and dura mater grafts, with cases of early-onset Alzheimer’s-like changes reported in 2024. The researchers stress that current screening tools are inadequate and that definitive risk quantification remains elusive, urging coordinated international research efforts.
This review could influence blood donation policies and public perception of transfusion safety, though the actual risk remains unquantified. Patients requiring frequent transfusions—such as those with blood disorders—may face heightened anxiety, while blood services might consider new screening measures if evidence strengthens. The findings also underscore broader questions about whether other neurodegenerative proteins could be transmissible, potentially reshaping how chronic diseases are viewed. However, without confirmed transmission in humans, the immediate societal impact is likely limited to research prioritization and cautious monitoring rather than immediate regulatory change.