Infectious Link to Alzheimer's Disease

Researchers from Philadelphia College of Osteopathic Medicine (PCOM) have completed work that shows a link between the bacterium Clyamydia pneumoniae and the amyloid plaques found in the brains of people who have sporadic, non-hereditary Alzheimer's Disease. Presented last month at The 8th International Conference on Alzheimer's Disease and Related Disorders in Sweden, their new research builds on their ground-breaking work published in Medical Microbiology and Immunology in 1998 that discovered chlamydia pneumoniae in 90 percent of brains taken from individuals who had suffered from Alzheimer's Disease. Their new work shows that the bacterium, when sprayed into the noses of mice, can cause progressive deposition of amyloid plaques, in essence creating a partial model of Alzheimer's Disease.

"We believe this could be a trigger mechanism for the pathology in Alzheimer's Disease," says lead researcher Brian Balin, PhD. "People have been suspecting this for decades but could not find anything. It is very difficult to pinpoint an infectious cause for a progressive, chronic disease. We also believe that our isolation of chlamydia pneumoniae from the human Alzheimer's Diseased brain and induction of pathology in normal mice is proof of principle that this can be a causative mechanism turning on pathology."

Chlamydia pneumoniae is a common bacterium to which almost the entire worldwide population has been exposed by age 70. It primarily causes inflammatory lung disease, but it also sometimes infiltrates the brain.