Alzheimer's May Get Transmitted Through Surgical Instruments, Scientists

Concern that tiny pieces of harmful proteins could be spread via surgical instruments leads scientists to call for more research into possible transmission.

The small study indicated that potential routes of transmission, such as surgical instruments, should be investigated.

New research shows that "fragments of sticky proteins" in the brains of people with Alzheimer's disease could potentially be spread to others via contaminated surgical instruments and other medical procedures, scientists warn, according to theguardian.

There is a possibility that metal instruments used during surgery may contract the harmful proteins that cannot be destroyed even through conventional sterilisation with formaldehyde.

The conclusion has been reached after scientists found that a small number of people who were killed by the Creutzfeldt-Jakob disease (CJD) after they were treated with growth hormone from cadavers had developed some changes in their brain due to Alzheimer's disease.

The conclusion was arrived at after doctors probed the brains of eight CJD patients who had been given pituitary growth hormone. They were given to children with stunted growth, till it was stopped in 1985.

Scientists found that six of the brains had an unusual build-up of protein called amyloid beta, which has been linked to the disease. Now aged 36 to 51 years, the patients do not seem to be carrying gene variants that lead to the quick onset of dementia.

It was John Collinge, director of the Medical Research Council Prion Unit at University College London, who pointed out that according to the study, there is a possibility that the hormone may have spread tiny pieces, or "seeds", of amyloid beta along with the abnormal proteins, or prions, that caused CJD in people.

It is significant that none of the patients developed Alzheimer's disease, or related brain changes, unless they died before the symptoms emerged.

Hence, can amyloid beta spread through alternative medical processes, called "iatrogenic routes"? Scientists referred to the procedures in the journal Nature.

"While there is no suggestion that Alzheimer's disease is a contagious disease and no supportive evidence from epidemiological studies that Alzheimer's disease is transmissible ... our findings should prompt consideration of whether other known iatrogenic routes of prion transmission, including surgical instruments and blood products, may also be relevant to amyloid beta," the authors write.

Collinge said that people could acquire amyloid beta "seeds" through a spontaneous, unlucky biological event, a faulty gene or through a medical accident. He said it cannot be transferred through blood transfusions, but added: "I think it's not unreasonable to have a look. My concerns would be more to see if there is a risk of seeding from metal surfaces. I think that is something we ought to prioritise."

John Hardy, a leading Alzheimer's researcher at UCL, said: "This is the first evidence of real-world transmission of amyloid pathology. It is potentially concerning."

However, scientists and doctors have urged people not to delay or cancel surgery due to the fear of contracting Alzheimer's. The chief medical officer, Sally Davies, said there was no evidence that Alzheimer's disease could be transmitted in humans through any medical procedure.

 "This was a small study on only eight samples," she said. "We monitor research closely and there is a large research programme in place to help us understand and respond to the challenges of Alzheimer's. I can reassure people that the NHS has extremely stringent procedures in place to minimise infection risk from surgical equipment, and patients are very well protected."