They describe five cases of Alzheimer’s disease contracted from growth hormone treatment of cadavers.
A group of researchers described in Natural medicine Five cases in the United Kingdom who developed Alzheimer’s-like dementia after being treated as children with cadaveric growth hormone, a treatment last given in 1982.
This discovery suggests that the disease can be transmittedalthough this is a very rare event and could be caused by repeated exposure to a hormone that is no longer used in medical procedures that It was last used in 1982..
Alzheimer’s disease (AD) is pathologically characterized by the deposition of beta-amyloid and neurofibrillary tangles of tau protein in the brain. “We previously reported human transmission of A and CAA in relatively young individuals who died of iatrogenic Creutzfeldt-Jakob disease (iCJD) after childhood treatment with pituitary growth hormone contaminated with cadaveric human prions (c-hGH). the likelihood that c-hGH recipients who do not die from iCJD may eventually develop Alzheimer’s disease,” the authors explain in the study.
“We describe recipients who developed dementia and biomarker changes across the phenotypic spectrum of AD, suggesting that AD, like CJD, has environmentally acquired (iatrogenic) forms as well as sporadic inherited forms,” says Gargi Banerjee , PhD, from the Prion Disease Research Unit at the National Hospital for Neurology and Neurosurgery in London, UK, and the principal investigator of the discovery.
There is no evidence that Alzheimer’s disease can be transmitted between people in everyday life, and there is no evidence that modern surgical procedures carry any risk of transmitting Alzheimer’s disease.
However, “although iatrogenic Alzheimer’s disease may be rare and there is no indication that it can be transmitted between people in everyday life, its recognition highlights the need consider measures to prevent accidental transmission through other medical and surgical procedures.
Tara Spears-Jones, group leader at the UK Dementia Research Institute and president of the British Neuroscience Society, explains to Science Media Center (SMC) UK that the study is a profile of eight people who received the injections. growth hormone extracted from human cadavers over several years in childhood, five of whom developed dementia 30-40 years later.
Scientists attribute these symptoms to the possible transmission of amyloid pathology associated with Alzheimer’s disease from growth hormone, which initiated the aggregation of this amyloid in the brains of these people. “Although this is possible based on this article and your previous data, This is not something people should worry about.because this type of growth hormone treatment is no longer used, and even in people receiving this growth hormone, this result is very rare.
In addition, it is impossible to know for sure whether these people developed dementia due to growth hormone treatment for several reasons: this study only included eight people (a very small sample size), some of whom also had other risks of developing dementia. such as mental retardation (in two cases) or (a variant) gene that significantly increases the risk of Alzheimer’s disease (one case), and the pathology shown in the article for people who donated post-mortem brain tissue is much milder than found in people who died from Alzheimer’s disease.
Andrew Doig, Professor of Biochemistry and Director of the Biochemistry Program at the University of Manchester (UK), adds that “the recognition of beta-amyloid transmission highlights the need to reconsider measures to prevent accidental transmission through other treatments and medical procedures. The results may have implications for the processes that drive other types of Alzheimer’s disease and may provide insight into therapeutic strategies, they conclude.”
There is no evidence that the mode of disease transmission presented here has ever occurred elsewhere. We are already very cautious about transferring brain tissue between people because of the small but real risk of transmitting prions, which can cause Creutzfeldt-Jakob disease.
There is evidence that amyloid beta aggregates can travel across brain synapses, spreading dementia. This work confirms this idea. It remains to be seen whether this work will have implications for therapeutic strategies. “The paper speculates about the possibility of different strains of beta-amyloid arising from different aggregate structures, but does not provide direct evidence for this.”
“Previous work had shown that beta-amyloid aggregates could be transferred to humans through human growth hormone, although we did not know whether they had any effect. This new work suggests for the first time that these aggregates may actually cause the amyloid-like disease Alzheimer’s disease.”
“It is well known that early-onset Alzheimer’s disease can be caused by mutations in the PSEN1, PSEN2 or APP genes. This is not the case here. Other possible explanations for the symptoms of Alzheimer’s disease include mental retardation in patients and other diseases associated with Alzheimer’s disease. , growth hormone deficiency, or effects of radiation therapy. All of these were excluded, leaving transmission of Alzheimer’s disease by growth hormone treatment as the best explanation for the disease’s symptoms. However, caution must be exercised because the study included only eight patients. accounts and some of the data on them are incomplete, such as genetic data.
“Although the new type of Alzheimer’s disease described here is of great scientific interest because it reveals new way of spreading the disease, there is no reason to fear this since the disease pathways ceased more than 40 years ago. “Transmission of disease from human brain to brain in this way should not happen again.”
“This is a very exciting study that provides more information about the risk of a transmissible form of amyloid beta, a protein involved in cerebral amyloid angiopathy and Alzheimer’s disease,” adds Bart De Struper, group leader at the UK Dementia Research Institute at University College. London.
As the authors note, according to current data, the risk of infection with a transmissible form of amyloid is very low. No one should second-guess or refuse any medical procedure, especially blood transfusions or neurosurgery, which save many lives every year around the world. “However, it is always important that we continue to review and analyze the evidence when it comes to public health. In previous correspondence involving several experts in the field, we have called for increased surveillance and long-term follow-up, especially after procedures. in the early stages of life that involve human fluids or tissues.
“Recommended action steps include conducting larger epidemiological studies, continuing to study risks using animal models, and developing sensitive, low-cost, high-throughput tests for beta-amyloid and other proteins to facilitate preventive sterilization of, for example, neurosurgical instruments.
Natural medicine https://doi.org/10.1038/s41591-023-02729-2