Alzheimer’s Disease could be transmitted under rare conditions?

An article on ScienceNews.org, written by Laura Sanders, explores an unprecedented finding where researchers have identified instances of iatrogenic Alzheimer’s disease, wherein five individuals developed the condition atypically early after receiving contaminated growth hormone injections during childhood. The study, published in Nature Medicine on January 29, details the cases of individuals who exhibited symptoms between the ages of 38 and 55. What sets these cases apart is that they ruled out the presence of known genetic mutations associated with early-onset Alzheimer’s.

The individuals in question had received growth hormone injections as children or teenagers, a treatment utilized for various growth disorders. Notably, these hormones were extracted from the pituitary glands of cadavers and combined into batches, a practice that is no longer employed. Some of these batches were found to be contaminated with prions, misshapen proteins causing Creutzfeldt-Jakob disease. This growth hormone treatment ceased in 1985, with synthetic versions now in use.

Earlier research by neurologist John Collinge and colleagues had identified elevated levels of amyloid-beta, a sticky protein characteristic of Alzheimer’s, in the brains of individuals who had died with Creutzfeldt-Jakob disease. This prompted concerns that the protein, along with prions, could have been transferred from donors. Subsequent studies revealed that amyloid-beta from these hormone batches could spread in the brains of mice, akin to infectious prions.

The recent study reports on eight additional individuals who had received contaminated growth hormone and were referred for clinical evaluation. While none had Creutzfeldt-Jakob disease, three had already been diagnosed with Alzheimer’s. Further examinations revealed two more with the disease and two exhibiting signs of cognitive impairment, while one remained asymptomatic.

The researchers suggest that the shared exposure to contaminated growth hormone is the most likely cause of Alzheimer’s in these cases. However, the certainty of this connection remains elusive. It’s plausible that underlying childhood conditions necessitating growth hormone treatments or other medical procedures may have contributed to early Alzheimer’s or cognitive issues. For instance, several individuals experienced seizures, which could potentially influence cognitive problems or brain pathology.

Despite the challenges in establishing a definitive link, the findings may offer insights into how Alzheimer’s takes root in the brain and whether amyloid-beta, akin to prions, induces misfolding in other forms of itself. The study underscores the need for extensive research to unravel the intricate details of how different forms of amyloid-beta spread, emphasizing that “a great deal more research needs to be done,” as stated by Collinge.