2024-01-29 17:24:34
Research carried out in the United Kingdom has confirmed for the first time the accidental transmission, through medical treatment, of the protein that causes Alzheimer’s, a disease until now only associated with old age or, to a lesser extent, heredity. genetics.
EFE/Juan Carlos Cárdenas
The discovery of this spread, the first accidental transmission of Alzheimer’s, no matter how extraordinary the circumstances in which it occurred, highlights the need to take extreme precautions in the opinion of the authors of this study, which was reported this Monday in the journal Nature Medicine. .
The study has confirmed that five patients who were treated with a contaminated growth hormone – coming from brain tissues of cadavers and out of use since 1985 – ended up developing the disease without having either age or genetic inheritance linked to it. This was contaminated with the amyloid beta protein, the accumulation of which is responsible for Alzheimer’s.
A ‘contaminated’ treatment
The growth hormone c-hGH, extracted from the pituitary glands of deceased people to treat height issues, was administered to 1,848 girls and boys in the United Kingdom between 1959 and 1985.
The suspension of its use in 1985 – and its replacement by a synthetic hormone – came from the discovery that some batches contained infectious proteins that cause Creutzfeldt-Jakob disease, a brain disorder that often leads to dementia.
In 2017-2018, more than 30 years after this treatment stopped being used, the authors of the present study analyzed stored samples of the growth hormone c-hGH and found that they were contaminated with the pathology associated with the amyloid beta protein despite from having been stored for decades.
When administered to mice, they saw that they developed Alzheimer’s, which led them to wonder what the evolution would have been of those girls and boys who received that treatment potentially contaminated with the amyloid beta protein.
“Our suspicion was that people exposed to that growth hormone who did not succumb to Creutzfeldt-Jakob disease and lived longer could have ended up developing Alzheimer’s disease,” one of the authors explained in a press conference. , neurosurgeon John Collinge, affiliated with University College London.
What the 8 cases studied reveal
The study of eight of these cases has shown that five began to show symptoms of dementia between the ages of 38 and 55, and currently either have been diagnosed with Alzheimer’s or meet all the diagnostic criteria for this disease.
Of the remaining three, one person met the criteria for mild cognitive impairment.
The unusually early age at which these patients developed symptoms suggests that they did not suffer from usual Alzheimer’s associated with old age, and in all five cases the existence of the gene that makes this disease hereditary in some cases was ruled out.
“There is no indication that Alzheimer’s disease can be transmitted between people during activities of daily living or routine medical care. The patients we have described received specific medical treatment that was discontinued in 1985,” emphasizes Collinge.
However, the authors do agree that the finding that Alzheimer’s could be transmitted, no matter how extraordinary the circumstances, sets a precedent and should lead “to review measures to prevent accidental transmission through medical or surgical procedures, in order to prevent these cases from occurring in the future.
Cautions
In a reaction reported by the Science Media Center platform, Tara Spiers-Jones, president of the British Society of Neuroscience, does not question the results of the study but does emphasize that “it is not something that should worry people.”
“There is no evidence that Alzheimer’s disease can be transmitted between individuals in activities of daily living, nor is there evidence to suggest that current surgical procedures carry any risk of transmission of the disease,” he adds.
Along the same lines, the professor of Biochemistry at the University of Manchester Andrew Doig calls for “being cautious” and emphasizes that despite its solvency, the study “only takes eight patients into account.”
“There is no reason to fear the spread of the disease, since the way it originated – this transmission – was stopped more than 40 years ago. Transmission of the disease from human brain to brain in this way should not happen again. occur,” he says.
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