While Alzheimer’s disease is prevalent the older a person gets, it develops with changes in the brain, not through contact with an Alzheimer’s patient. However, new research finds it may have been transmitted through other medical treatments, in very rare cases.
Scientists from University College London (UCL) recently investigated the cognitive health of adults who had received pituitary growth hormone from cadavers when they were kids to address conditions leading to insufficient growth. The team looked into this due to past research, which found that Alzheimer’s hallmark beta amyloid and cerebral amyloid angiopathy were present in young adults who had received this treatment as children and then later died from the neurodegenerative Creutzfeldt-Jakob disease. The research had shown that the growth hormone had been contaminated with proteins linked to the disease, as well as beta amyloid seeds. Due to this, the treatment was discontinued nearly 40 years ago and replaced with a synthetic growth hormone.
This led researchers to study whether those who didn’t die from Creutzfeldt-Jakob disease ended up developing Alzheimer’s later due to beta amyloid acquired from cadavers. The findings, published in Nature Medicine, showed that five cases of Alzheimer’s appear to be linked to this treatment.
Professor John Collinge, lead author and Director of the UCL Institute of Prion Diseases, says, “There is no suggestion whatsoever that Alzheimer’s disease can be transmitted between individuals during activities of daily life or routine medical care. The patients we have described were given a specific and long-discontinued medical treatment which involved injecting patients with material now known to have been contaminated with disease-related proteins.
“However, the recognition of transmission of amyloid-beta pathology in these rare situations should lead us to review measures to prevent accidental transmission via other medical or surgical procedures, in order to prevent such cases occurring in future.”
Collinge and his team studied eight patients who had received the cadaver-derived growth hormone treatment, which was given to at least 1,848 people in the United Kingdom between 1959 and 1985. Of the eight studied, five had either been diagnosed with Alzheimer’s or had symptoms meeting diagnosis criteria.
These patients had begun developing neurological symptoms much earlier than older-onset patients, when they were between 38 and 55. This suggests the patients were not affected by beta amyloid stemming from sporadic Alzheimer’s that hits seniors. The researchers also determined that the patients did not have genetic risk factors.
While the evidence suggests the treatment caused patients to develop Alzheimer’s, which has safety implications for other treatment procedures, the team says it may also help better understand the disease itself.
Jonathan Schott, study co-author and professor at UCL Queen Square Institute of Neurology, says, “It is important to stress that the circumstances through which we believe these individuals tragically developed Alzheimer’s are highly unusual, and to reinforce that there is no risk that the disease can be spread between individuals or in routine medical care. These findings do, however, provide potentially valuable insights into disease mechanisms, and pave the way for further research which we hope will further our understanding of the causes of more typical, late onset Alzheimer’s disease.”
To read the whole study, click here.