A research team from London claims to have shown that Alzheimer’s is transferable. However, one expert finds this assessment “premature”.
London – Alzheimer’s is an insidious disease that wreaks havoc in the human brain long before people notice the first symptoms of Alzheimer’s. The protein amyloid beta is folded incorrectly and clumps together in the brain. Small accumulations arise between the nerve cells, which lead to cognitive decline. There is currently no cure for the neurodegenerative disease, but there has been some progress in medications and therapies.
A research team from University College London has now discovered something that sounds frightening at first glance: Alzheimer’s is apparently transmissible.
Can Alzheimer’s be transmitted? New study describes eight patients
At least that’s what the research team led by neurologist John Collinge concludes from their work in the specialist journal Nature Medicine published became. In it, Collinge and his team describe eight people who were injected with a certain growth hormone in their childhood – and who now developed neurological symptoms between the ages of 38 and 55. Five of these people had symptoms of dementia and had either already received an Alzheimer’s diagnosis or met the criteria for it, one said notice to the study.
Another person therefore met the criteria for mild cognitive impairment. Because the patients were unusually young when they developed the symptoms, the research team believes this is not the usual Alzheimer’s disease that is associated with age. Inherited Alzheimer’s disease was also ruled out in five patients on whom the researchers were able to carry out genetic tests.
Growth hormone could have transmitted Alzheimer’s disease
The research team therefore focused on the growth hormone that the patients received in childhood. It was a growth hormone (c-hGH) obtained from the brain tissue of deceased people, with which at least 1,848 people were treated in Great Britain between 1959 and 1985. However, when some batches of the growth hormone were found to cause Creutzfeld-Jakob disease, the drug was replaced with synthetic growth hormones in 1985.
In a 2018 study, researchers suspected that people who were injected with contaminated c-hGH and who did not develop Creutzfeldt-Jakob disease would later develop Alzheimer’s disease. This is exactly what Collinge’s research team wants to have shown. However, the study leader immediately gives the all-clear: “There is no evidence that Alzheimer’s disease can be transmitted from person to person during activities of daily life or during routine medical care.”
Alzheimer’s disease transmission study could provide insight into disease mechanisms
Co-author Jonathan Schott adds: “It is important to emphasize that the circumstances under which these individuals tragically developed Alzheimer’s are highly unusual.” However, the results could provide valuable insight into the mechanisms of Alzheimer’s, says Schott further.
Action is now needed, says Collinge: “The knowledge that amyloid beta pathology has been transmitted in these rare cases should prompt us to review measures to prevent accidental transmission through other medical or surgical procedures in order to prevent such cases to avoid the future.”
Expert restricts: Alzheimer’s study is based on only five people
Michael Beekes from the Robert Koch Institute (RKI) in Berlin was not involved in the study. He is of the opinion that it is an “important pilot study”, but also has some reservations: “However, the conclusions of the study regarding the transmissibility of Alzheimer’s disease are based on only five patients who were diagnosed three to four decades after treatment Growth hormones have developed dementia.”
Two of the five people have had intellectual disabilities since childhood, “which are associated with an increased likelihood of early onset dementia,” Beekes continued. It is also not a “definitive neuropathological proof of Alzheimer’s”.
The scientist would like to see further studies on the topic and emphasizes: “In my opinion, it seems premature to describe the patients’ clinical syndrome as iatrogenic Alzheimer’s disease – that is, caused by medical treatment – based on the currently reported data, and to therefore view Alzheimer’s disease as transmissible .” (tab)