A study conducted in January 2015 by John Collinge and his team of pathologists has opened the door to the theory that rogue proteins, known as amyloids, might share properties of misfolded proteins, known as prions, including their transmissibility.
The study was conducted on autopsied brains from four individuals who were previously injected with growth hormones. All four individuals died in their 40’s or 50’s as a result of Creutzfeldt-Jakob disease, a rare disease caused when the brain is contaminated by a prion. The study discovered that while the individuals died at relatively young ages, their brains were scarred with white plaque that is typically seen in people with Alzheimer’s, a disease that generally affects much older individuals. Collinge and his team concluded that this white plaque was a result of prion transmission from the growth hormone injections. This conclusion has stirred some controversy in the scientific field, as it suggests that Alzheimer’s may be transmissible from one person to another. It raises the possibility that certain aspects of amyloid-β protein can be transferred through medical procedures where fluid or tissue from one person is introduced into another, such as a blood transfusion or organ transplant.
Collinge published his findings in the September issue of Nature. Careful to not stir panic in the public and scientific community, Collinge stressed that the study did not conclude that Alzheimer’s is contagious, but rather brought to light how some medical procedures can transfer amyloid-β proteins without our knowledge. The results of the study have trickled down to worldwide academic discussions and a push for further understanding of putative amyloid seeds and varying strains of amyloids. Some members of the scientific community raised concern about creating premature panic when there could be other biological explanations. Collinge’s study used a small number of subjects, the subjects had no symptoms of Alzheimer’s prior to death, and their conditions may have been caused by the presence of other proteins.
It is unquestionable that Collinge’s study has highlighted the unknown and the need for further research. If his transmissibility theory proves to be true, it means amyloid seeds stick to metal surgical instruments and are not removed by normal sterilization. Consequently, the seeds may be transferred during surgery, whereby they remain in the body for years, spreading into plaque and inducing other pathological changes that cause neurodegenerative diseases.