A group of Spanish scientists reveal that traces of fungus have been found in the brains of deceased Alzheimer’s patients, opening the possibility that the disease may be caused by an infectious microbe.
While there is no conclusive evidence, the researchers say their findings could lead to new perspectives for effective therapy for Alzheimer’s patients. This could mean the disease may be cured using an antifungal treatment, the team notes in the journal Scientific Reports.
The researchers say they had found cells and other material from “several fungal species” in the brain tissue and blood vessels of all 11 Alzheimer’s sufferers analysed.
They say this might explain the diversity observed in the evolution and severity of clinical symptoms in each patient. The researchers also note that a fungal cause would fit well with the characteristics of Alzheimer’s, including the slow progression of the disease and inflammation.
However, they point out that fungal infection may be the result, not the cause, of Alzheimer’s. Since sufferers of the disease may have a weaker immune response, or changes in diet or hygiene, it could leave them more exposed to fungi.
The team says that clinical trials will be necessary to establish a causal effect of fungal infection of Alzheimer's. Currently, a number of highly effective antifungal compounds with little toxicity are present, they note. A combined effort from the pharmaceutical industry and clinicians is needed to design clinical trials to test the possibility that AD is caused by fungal infection.
Previous studies have found genetic material from viruses and bacteria in the brains of Alzheimer’s patients, and viruses which cause herpes and pneumonia have been suggested as potential AD “agents,” according to the study’s authors.
Currently, the main suspect for the disease has been brain “plaques” caused by a build-up of sticky proteins but trials with drugs targeting these have yielded disappointing results. With the new study, a possible cause has been added to the list of hypotheses.
Last month, a study from the University of College London suggested that certain medical procedures may pose a rare but potential risk in spreading Alzheimer’s disease. Based on a post-mortem brain analysis of people with Creutzfeldt-Jakob disease, or CJD, the researchers said that contaminated surgical instruments or injections could also transmit protein found in Alzheimer’s disease.
Alzheimer’s disease is the most common form of dementia, which affects nearly 50 million people worldwide and causes some 7.7 million new cases per year, according to the World Health Organisation.
A major risk factor of the disease is old age, and till date, there is no therapy to stop or reverse its symptoms, which includes memory loss and disorientation, as well as anxiety and aggressive behaviour.