Alzheimer's can be 'transferred by blood transfusion' during surgery
The seeds of Alzheimer's disease can be transmitted through medical procedures, scientists have found, leading experts to call for the monitoring of blood transfusions from the elderly and those with a family history of dementia.
In 2015, researchers at University College London discovered that people who developed Creutzfeldt-Jakob disease (CJD) following treatments with human growth hormone also showed signs of Alzheimer's in their brains after death.
The scientists tracked down vials of the same hormone and found that it did indeed contain misfolded amyloid-beta proteins, capable of setting off the deadly chain reaction that can lead to dementia.
When they injected the hormone into the brains of mice, the animals began to develop the same signs of neurodegenerative disease.
Author Prof John Collinge, of the UCL Institute of Prion Diseases, said: "We have now provided experimental evidence to support our hypothesis that amyloid beta pathology can be transmitted to people from contaminated materials.
"We cannot yet confirm whether medical or surgical procedures have ever caused Alzheimer's disease itself in people, or how common it might be to acquire amyloid pathology in this way.
"It will be important to review risks of transmission of amyloid pathology by other medical procedures still done today, including instruments used in brain surgery, drawing on other research and what we already know about accidental CJD transmission."
However, Alzheimer's charities sought to reassure people that it was highly unlikely the disease would be passed on during a medical procedure.
Dr David Reynolds, chief scientific officer at Alzheimer's Research UK, said: "Although the findings might sound concerning, strict guidelines surrounding the sterilisation and use of surgical equipment have been introduced since the discovery of prion protein contamination and CJD."