SCIENTISTS have found the first evidence that Alzheimer’s disease can be transmitted between people.
The condition is the top cause of dementia and is usually brought on by old age.
But a study has confirmed five people developed it at a young age, between 38 and 55, after receiving hormones harvested from the brains of dead donors.
Another three showed signs of brain damage or memory loss.
The human growth hormone treatment was given to at least 1,800 children with growth problems between 1959 and 1985.
It was stopped because it triggered deadly Creutzfeldt–Jakob disease, aka mad cow disease, in some patients.
Decades later, some samples were found to be contaminated with toxic amyloid-beta proteins, which are a hallmark of Alzheimer’s.
Scientists now believe a handful of those children have developed dementia in middle age due to the transfer of harmful proteins from the dead donors’ brains.
Study author Dr Gargi Banerjee, from University College London, said: “We have found that it is possible for amyloid-beta pathology to be transmitted and contribute to Alzheimer’s disease.
“This transmission occurred following repeated treatments with contaminated material, often over several years.”
Experts insist this does not mean Alzheimer’s can be transmitted any other way or in a medical procedure like a blood transfusion or organ transplant.
Professor Andrew Doig, from the University of Manchester, said: “This new type of Alzheimer’s is of great scientific interest but there is no reason to fear it.
“The way in which the disease was caused was stopped over 40 years ago.
“Disease transmission from human brain to brain in this way should never happen again.”
This is of great scientific interest but there is no reason to fear it.
Professor Andrew Doig
Dr Bart de Strooper, from the UK Dementia Research Institute, added: “No-one should reconsider or forego any medical procedure, especially blood transfusion or neurosurgery which save many lives every year.”
The study, in the journal Nature Medicine, said it is possible more people developed Alzheimer’s this way.
Dr Susan Kohlhaas, of Alzheimer’s Research UK, said: “This study has revealed more about how amyloid fragments can spread within the brain.
“This gives us further clues on how Alzheimer’s disease progresses and potential new targets for the treatments of tomorrow.”
Nearly a million people in the UK have dementia and more than six in 10 cases are caused by Alzheimer’s disease.
ALZHEIMER'S disease is the leading cause of dementia, affecting around 600,000 people in the UK.
Alzheimer’s disease is a build-up of toxic proteins, usually called amyloid or tau, in the brain.
Clumps of these damage, block off and kill vital nerve cells.
Damage to the nerves in the brain gradually destroys the organ, robbing patients of their muscle control, thinking power and emotions.
The cause of Alzheimer’s disease is not well understood but some things can increase your risk:
Age is the biggest risk factor – 95 per cent of cases begin after retirement age and your risk of developing Alzheimer’s doubles every five years after the age of 65.
Other risks include:
Alzheimer’s often develops slowly over many years and it is usually too late for treatment by the time symptoms get bad.
Early to middle-stage symptoms include:
There is no cure for Alzheimer’s disease but medicines can help to reduce the symptoms.
Drugs regulators will in 2024 decide whether to approve a new class of medicines that claim to be able to clear damaging proteins out of the brain in the very early stages of Alzheimer’s.
Source: NHS
