Is there a link between Common Virus and Alzheimer’s disease?
FFE Health News Staff
A new study on the brains of older adults suggests that contracting a common virus (CMV) may help develop Alzheimer’s disease.
The study found an association between patients’ immune responses to CMV and signs of Alzheimer’s disease.
However, more studies are still needed to understand how an active CMV infection might be related to this most common form of dementia, said study researcher Dr. Julie Schneider, of the Rush University Alzheimer’s Disease Center in Chicago.
The study did not show a cause-and-effect link between CMV and Alzheimer’s. It is possible that other stimulants of inflammation, including other viral infections, might also lead to the brain changes seen in the study, which could cause a decline in cognitive function leading to Alzheimer’s disease.
In the new study, Schneider and her colleagues analyzed blood and cerebrospinal fluid (brain- and spinal-cord fluid) samples from the bodies of people who were part of an aging-and-dementia study during their lives.
The researchers found that 80 percent of the patients who were positive for a CMV infection had high levels of an inflammation marker in their cerebrospinal fluid, while none of the patients who were negative for the virus had this marker present. Such a clear-cut difference supports the idea that CMV may specifically cause inflammation related to Alzheimer’s, said study researcher Nell Lurain, professor of immunology at Rush University.
The patients with higher levels of antibodies against CMV were also more likely to have brain cells with aggregated tau proteins, called neurofibrillary tangles that have been connected to Alzheimer’s disease.
While most people are carriers of the CMV virus, generally only those with weakened immune systems have symptomatic, active CMV infections. The virus may infect the brain and spinal cord, and has been shown to increase inflammation. This inflammation, which can occur in the brain, is thought to contribute to Alzheimer’s, and perhaps other diseases that result in the degeneration of nerve cells.