The Transmissibility of Alzheimer's Disease: A New Dimension to an Old Debate

Alzheimer's disease, a neurodegenerative condition that primarily affects the elderly, has long been considered a non-transmissible disease. However, recent research has ignited discussions around the possible transmission of Alzheimer's under certain circumstances. This development offers a fresh perspective on the ongoing discourse around the origins of the disease, challenging conventional wisdom and opening new avenues for research and treatment.

A Controversial Discovery

In a groundbreaking study led by researchers from the National Hospital for Neurology and Neurosurgery in London, it was discovered that Alzheimer's disease might have been transmitted to individuals who were treated with a contaminated growth hormone. The hormone, derived from the pituitary gland of deceased donors, was used in treatments between 1959 and 1985. Out of 1,848 patients treated in the UK, eight developed dementia, with biomarker changes consistent with Alzheimer's disease. This study suggests that under certain circumstances, Alzheimer's could be transmitted from person to person, a revolutionary concept in the field of neurodegenerative diseases.

Transmission through Medical Treatment

University College London (UCL) researchers identified a connection between a specific growth hormone treatment and the onset of Alzheimer's disease. The hormone, extracted from the pituitary glands of deceased individuals, was found to increase the amounts of amyloid-beta protein in the brain, a key indicator of Alzheimer's. Of the eight patients who underwent this treatment as children, five developed symptoms of dementia and were subsequently diagnosed with Alzheimer's disease. The study raises crucial questions about the potential for beta-amyloid protein to propagate itself, exacerbating memory loss and the progression of Alzheimer's.

Prions and Alzheimer's

The study also sparked a controversial discussion among medical professionals on the classification of diseases involving misfolded proteins, like amyloid-beta plaques and tau tangles. It suggested that these could be considered as prion diseases, a class of diseases caused by misfolded proteins that cause other proteins to misshape, leading to neurodegenerative conditions. The possibility of Alzheimer's being a prion disease, albeit transmissible in very limited circumstances, has opened a new direction in Alzheimer's research.

Minimizing the Risks

Despite these alarming findings, the risk of Alzheimer's transmission is considered very low. The practice of using donated human growth hormone (hGH) was discontinued in 1985 due to the risk of transmitting Creuztfeldt-Jakob disease (CJD), another prion disease. Today, hGH is synthetically produced, eliminating the risk of transmission from cadaver-derived hormones. Furthermore, the study's population was small and the findings need further replication and confirmation. It was emphasized that Alzheimer's disease cannot be contracted through casual contact or caregiving for individuals with the disease.

Implications of the Study

The study has significant implications for the scientific and clinical communities. It underlines the need for stringent sterilization of surgical instruments to eliminate all methods of pathogen transmission. It also offers convincing evidence that Alzheimer's disease can be transmitted in humans under specific circumstances, with an incubation period of approximately 35 years. This discovery could potentially revolutionize our understanding of Alzheimer's disease and pave the way for new strategies for its prevention and treatment.

In conclusion, while the discovery of transmitted cases of Alzheimer's disease has added a new dimension to our understanding of the disease, it is important to remember that these findings pertain to very specific circumstances. Therefore, further research is needed to better understand the implications of these findings and to develop effective preventive and treatment strategies.