A brain protein linked to Alzheimer’s disease might potentially be transmitted to people during neurological procedures, a new preliminary study suggests.
Genetically engineered lab mice developed amyloid-beta deposits in their brains after they were injected with amyloid-laced samples of human growth hormone taken from decades-old human cadavers, researchers found.
“We have now provided experimental evidence to support our hypothesis that amyloid-beta pathology can be transmitted to people from contaminated materials,” said senior researcher Dr. John Collinge. He is head of University College London’s department of neurodegenerative disease.
Clumps of amyloid-beta in the brain are a hallmark of Alzheimer’s disease, although researchers still don’t understand the relationship between these clumps and the degenerative brain disease.
Collinge pointedly noted that this study does not mean that you can catch Alzheimer’s from another person. And animal findings often don’t replicate in humans.
“Although we’re generating evidence that Alzheimer’s pathology may be transmissible, there’s absolutely no suggestion that Alzheimer’s disease itself is a contagious disease,” he said.
Rebecca Edelmayer, director of scientific engagement at the Alzheimer’s Association, went even further, noting that the new study did not look at Alzheimer’s disease at all.
“They’re looking at a buildup of amyloid in the brain, which is not the same thing as Alzheimer’s,” Edelmayer said.
“This is very, very preliminary research,” she added. “It’s very interesting, but preliminary.”
The mouse study is the latest chapter in a decades-long saga involving contaminated cadaver-derived human growth hormone (c-HGH).
Between 1958 and 1985, about 30,000 children with growth deficiencies were treated with human growth hormone drawn from the pituitary glands of corpses, scientists explained in an editorial accompanying the new study.
In 1985, three of these children were diagnosed with Creutzfeldt-Jakob disease (CJD), a fatal illness that causes progressive and irreversible brain damage.
The use of cadaver-derived HGH was subsequently abandoned. Doctors now prescribe a synthetic form of human growth hormone.
Overall, more than 200 people treated with c-HGH worldwide have died of CJD, the researchers said.
In 2015, Collinge and his colleagues reported that these c-HGH injections appeared to have “seeded” amyloid-beta into the brains of at least some of the patients.