Can Alzheimer's Disease Be Transmitted? Unraveling an Intriguing Medical Mystery

Uncovering the Link Between Alzheimer's and Human Growth Hormone Treatments

A ground-breaking study published in Nature Medicine has shed light on a startling revelation - Alzheimer's disease may be transmissible under very specific circumstances. This inference was drawn from the long-term observation of patients who had received human growth hormone (hGH) from deceased donors, a practice that ceased in 1985. The particularly interesting aspect of this study is the conceivable connection between Alzheimer's disease and prion diseases, which are known to be transmissible.

The Role of Human Growth Hormone and Prion Diseases

The discontinued medical practice involved extracting growth hormone from the brain tissue of deceased individuals. This hormone was then administered to patients, typically children, who required it. However, after approximately 200 patients developed Creuztfeldt-Jakob disease (CJD) - a condition caused by prions - the practice was halted.

Prions, proteins that can fold in multiple structurally distinct ways, can trigger the development of a range of fatal neurodegenerative diseases, including CJD. The study identified five patients with early-onset Alzheimer's disease who had received the donated hGH, leading the researchers to conclude that the hGH was the likely cause of the disease in these cases.

The Transmission of Alzheimer's: A Rare Phenomenon?

While Alzheimer's disease is commonly understood as a non-contagious condition, this study indicates that it can be transmitted under extremely rare conditions. In the reported cases, the recipients of the tainted hGH injections developed early Alzheimer's disease, showing higher than usual levels of the sticky protein A-beta in their brains. This protein is known to accumulate in the brains of individuals with Alzheimer's disease.

It is important to note, however, that the absolute risk of transmission remains very low. The transmission of Alzheimer's disease cannot occur through person-to-person contact, but the study does raise concerns about potential risks of transmission through certain medical or surgical procedures.

Implications of the Findings and Future Directions

Despite the small sample size and the need for replication and confirmation, this study opens new avenues for understanding the etiology of Alzheimer's disease. The findings suggest that amyloid-beta pathology's transmission in these rare situations may have implications for understanding and treating Alzheimer's disease.

The research also underscores the importance of informed caution in the preparation of surgical instruments, handling of tissues, and implementation of therapeutic biologics, particularly those derived from human sources. It also paves the way for further research, which may enrich our understanding of the causes of more typical, late-onset Alzheimer's disease.

A Word of Caution to the Public

While these findings are undoubtedly intriguing, it is essential to emphasize that the circumstances through which these individuals tragically developed Alzheimer's are highly unusual. There is no risk that the disease can be spread between individuals or in routine medical care. Experts have stressed that this does not indicate that Alzheimer's disease can be passed between people through everyday activities or routine care, and there is no cause for concern for the health of the general population.

Patients now receive synthetic alternatives to hGH, which have been approved for safety. Therefore, there is no need for the general population to reconsider or forego any medical procedures based on these findings. The study provides an interesting perspective on the transmission of Alzheimer's disease but should not cause undue alarm.