Lancet review examines possible amyloid-beta transmission through blood transfusions

A review and opinion piece published in The Lancet and led by UCL (University College London) and UCLH researchers discusses the possibility that blood transfusions may inadvertently transmit harmful brain proteins, and whether additional safety measures are warranted as a precaution whilst further research is conducted to better understand these potential risks.

Professor John Collinge said: "Blood transfusions are important and save many lives. However, to ensure that they are as safe as they can possibly be, it's important that we thoroughly investigate any potential risks."

The authors consider the evidence for transmission of amyloid-beta, a protein associated with two diseases: Alzheimer's disease, a type of dementia, and cerebral amyloid angiopathy (CAA), which causes brain haemorrhages (strokes caused by bleeding).

Professor Collinge and colleagues review the evidence available on whether amyloid-beta pathology could potentially be transmitted through blood transfusions. The researchers point to a large Scandinavian epidemiological study, published in 2023, which found that recipients of blood from donors who later developed multiple brain bleeds (a marker of CAA) had a higher risk of brain bleeds themselves. While these findings do not prove causation, the authors of the new Lancet article say the findings raise questions about the possible transmission of amyloid-beta and CAA through blood transfusion.