Last December, a team of scientists working collaboratively under the guidance of the University of Bonn and the University of Massachusetts discovered that there was an association between chronic inflammation and the death of brain nerve cells. This discovery led them to theorize that chronic inflammation could possibly lead to the development of Alzheimer’s disease.
A different study now underway is focusing on a similar theory. The new study, initiated in January of this year, is led by Delphine Boche, Lecturer in Clinical Neurosciences at Southampton, England. The researchers are looking into the possibility that protective inflammation can change to damaging inflammation when the immune system of a person with Alzheimer’s is challenged by an infection elsewhere in the body. In other words, the immune system goes beyond its role as protector of the body and causes damage, just as it does in an autoimmune disease.
Boches says that, "Many of the known risk factors for Alzheimer's, like age, obesity and diabetes, increase inflammation in the brain and we think that could be another risk factor…There is already evidence that the immune system is on high alert in people with Alzheimer's and we think that an extra trigger, like an infection, could tip the balance and make immune cells switch from being protective to harmful."
Boche and her colleagues are using brain tissue donated by people who had Alzheimer’s disease when they died. While referencing the donor’s medical records, the researchers will compare the brains of those who had infections with those who did not.
The team is particularly interested in immune cells known as "microglia," which clean up cellular debris. The study team’s focus is to determine if infection causes distinct changes in microglia of people with Alzheimer's. Boche says the team believes that the damaged microglia may produce chemicals that are harmful to surrounding cells, making Alzheimer's worse. This research team, like so many others, believes that in order to find a way to cure Alzheimer’s, or at least slow it down, they need to understand just how the disease progresses.
I remember the effect that my mother-in-law’s urinary tract infection and later, her pneumonia, had on her dementia. While she lived two years after clearing up the pneumonia, her quality of life had taken an irreversible dive. I always felt that her infections accelerated her dementia. These studies certainly correlate with my experience.
Inflammation has surfaced as one cause in the development of many diseases including heart disease and cancer, so it’s not surprising that it likely affects Alzheimer’s disease, as well. More studies will need to be conducted before researchers can come to solid conclusions about the effect that infection has on inflammation in the body, but they’ve made a good start.