Alzheimer's Disease Possibly Transmittable: Study

A new research provides evidence that Alzheimer's could possibly be a transmittable disease.

Researchers from the University of Zurich and Medical University Vienna found that patients who have received brain grafts of dura mater from donor cadavers died later from Creutzfeldt-Jakob disease (CJD). Dura mater is a membrane that envelops the brain and spinal cord and it is a mandatory procedure given to patients to let their brains repair after undergoing surgery.

CJD is a degenerative brain condition that progresses to dementia and then death. According to Mayo Clinic, the disease resembles other brain disorders such as Alzheimer's Disease, but CJD is more progressive.

Researchers defined Alzheimer's disease as "progressive dementia" with "brain plaques consisting of the Aβ protein." While it was widely known that it is not a transmissible disease, they found that they found more plaques in mice when they injected them with plaques taken from brains of Alzheimer's patients.

The autopsies were detailed in the Swiss Medical Weekly.In their autopsies, lead researcher Karl Frontzek and colleagues found Aβ plaques in 5 of 7 brains in younger patients who received dura mater grafts who died of Creutzfeldt-Jakob disease. The plaques were found to be higher in brains who received the graft than those who did not undergo the procedure, according to the researchers via EurekAlert.

"Further studies will be needed to elucidate whether such pathology resulted from the seeding of Aβ aggregates from the grafts to host tissues," the researchers said, as noted by Daily Mail.

"Whilst the iatrogenic transmission of aggregated Aβ is one of several possible explanations for the findings reported here, the growing circumstantial evidence for such transmission should prompt a critical re-evaluation of the decontamination procedures for surgical instruments and drugs of biological origin, with the goal to ensure the complete absence of potentially transmissible contaminants."

This is the second case which provides evidence that Alzheimer's may be transmissible. In the article published in the journal Nature, a September study by University College London scientists found that in the autopsies eight young patients who died of CJD after receiving grafts have amyloid plaques in their brains and blood vessels.

The article notes that the studies did not imply that Alzheimer's can be passed on through normal human physical contact. However, if the theory of amyloid seeding being transmissible was true then surgical instruments used in the brain might become infected as standard sterilization cannot remove the stick amyloid-β proteins.