Rare cases of possible spread of Alzheimer’s disease found in patients receiving discontinued treatment

Rare cases of possible spread of Alzheimer’s disease found in patients receiving discontinued treatment

Early symptoms of dementia in five adults may be linked to now-discontinued human growth hormone treatment they received decades ago as children, a new study suggests.

A study published Monday in the journal Nature Medicine provides the first reported evidence of medically acquired Alzheimer’s disease in living people. In these cases, the early symptoms of dementia patients may be due to the possible transfer of amyloid-beta protein, a key factor in Alzheimer’s disease, when it forms plaques in the brain.

Abnormal accumulation of amyloid-beta in the brain has been linked to Alzheimer’s disease, and new research suggests that amyloid-beta contamination may be linked to early dementia symptoms in study patients. The research findings do not suggest that Alzheimer’s disease is contagious or spread like viral or bacterial infections, but they do raise new questions about Alzheimer’s disease and other degenerative diseases.

“I want to emphasize that these are very rare cases and most of them involve medical procedures that are no longer used,” said John Collinge, lead author of the study and director of the Prion Disease Institute at University College. London. . press conference

All five adults had growth hormone deficiency in childhood and received specially made pituitary growth hormones. The pituitary gland is located at the base of the brain, and human growth hormone, or HGH, is a natural hormone produced and released by the gland to promote growth in children.

According to the study, these patients were among at least 1,848 people treated with cadaver pituitary growth hormone in Britain between 1959 and 1985. At the time, this treatment was also used in other parts of the world, including the United States. The treatment was stopped after cases of the rare brain disease Creutzfeldt-Jakob disease were found to be linked to the administration of human growth hormone contaminated by the dead.

New research shows that repeated exposure of a body contaminated with both Creutzfeldt-Jakob disease prions and amyloid-beta seeds to HGH over many years can spread Alzheimer’s disease. Prions are proteins that can act as infectious agents of neurodegenerative diseases.

The researchers wrote in their study that under certain conditions, Alzheimer’s disease can be contagious as well as diseases called “prion diseases,” a family of rare progressive neurodegenerative diseases known to be linked to prion proteins, including Creutzfeldt-Jakob disease. . or CJD. Although Alzheimer’s disease is not a prion disease, some separate studies show that two proteins characteristic of Alzheimer’s disease, amyloid beta and tau, behave like prions.

“It appears that the events of Alzheimer’s disease are very similar in many respects to human prion diseases such as CJD,” Collinge said at a press conference. “This will increase the effect of treating Alzheimer’s disease.”

In 2015, researchers previously described “possible proof” that the transfer of amyloid-beta protein from the body’s growth hormone to the recipient is possible, and in 2018 they studied it in laboratory mice.

“We now provide evidence that Alzheimer’s disease is also contagious under certain conditions,” researchers from University College London and the UK’s National Hospital for Neurology and Neurosurgery wrote in their study. Although they add that this type of infection is “rare” and there is no indication that amyloid-beta can be transmitted between people in daily activities or in modern routine care.

“When the production of human growth hormone was stopped in the 1980s due to an outbreak of Creutzfeldt-Jakob disease, strict procedures were put in place to minimize cross-contamination. But in light of these findings, the researchers recommend that treatment procedures be reviewed to ensure that such rare cases of Alzheimer’s disease do not occur in the future,” said Dr Susan Kohlhaas, Director of Research and Partnerships at Alzheimer’s Research UK. a new study is in an article shared by the UK Center for Science Media. in the statement.

“This study suggests that, in very rare cases, Alzheimer’s disease can be transmitted between people through human growth hormone from deceased donors. It should be emphasized that this treatment is no longer used today and has been replaced by synthetic growth hormone,” Kohlhaas said in a statement. It is important to emphasize that this is the only recorded case of Alzheimer’s disease being transmitted between humans.”

Dr. Richard Isaacson, who was not involved in the new study, said in an email that he suspected. for some time that Alzheimer’s disease could be contagious like prion diseases, but his previous studies did not prove this. ,” said Isaacson, director of research at the Institute of Neurodegenerative Diseases in Florida.

He added that “the public has nothing to fear” because this type of human growth hormone therapy is no longer used in clinical practice, but the study emphasizes the importance of instrument sterilization and decontamination between surgeries.

Although there is no indication that amyloid-beta can be transferred between people during daily activities, “recognition of this highlights the need to reconsider measures to prevent accidental transmission through other medical and surgical procedures,” the researchers wrote in the study.

“I’m also interested in how these results can inform potential therapeutic targets and strategies in the future,” Isaacson said of Alzheimer’s disease.

The researchers studied eight cases in which the subject had previously been treated with human growth hormone taken from the pituitary gland of a cadaver. They were all treated like children. Five patients were still alive and were 50 years old at the time of the study. The other three died at the ages of 57, 54 and 47.

The researchers found that five patients had symptoms of early dementia and three.