An opinion piece and literature review published in The Lancet examines the potential risk of amyloid beta transmission through transfused blood products. Amyloid beta is a protein associated with Alzheimer's disease and cerebral amyloid angiopathy (CAA).
Dr Susan Kohlhaas from Alzheimer's Research UK stated that the review highlights an important gap in knowledge. While evidence suggests amyloid beta can be transmitted in very rare circumstances through certain, mainly historic, medical procedures, it is not clear how significant any risk might be from blood transfusions.
Experts emphasise that the review does not show that receiving a blood transfusion causes Alzheimer's disease. Professor Sir John Hardy of the UK Dementia Research Institute, UCL, noted that while there is a demonstrated risk of amyloid pathology transmission through amyloid-containing tissues, the risk through blood transfusion is likely small but unknown without systematic investigation.
Professor Bart De Strooper, also from the UK Dementia Research Institute, UCL, clarified that the opinion piece presents no new material or data. He added that it would be premature to worry about amyloid-beta transmission through blood transfusion, as there is no convincing evidence.
Dr Richard Oakley from Alzheimer's Society reiterated that the opinion piece does not present new evidence that amyloid beta can be transferred between people. He stressed that blood transfusions are vital, life-saving treatments, and people needing them should continue to receive them.