Herpes May Be Alzheimer’s Risk Factor

A gene known to be a major risk factor for Alzheimer’s disease puts out the welcome mat for the virus that causes cold sores, says a U.S. study.

Study leader Dr. Howard Federoff of the University of Rochester Medical Center says the study adds some scientific heft to the idea, long suspected by some scientists, that herpes somehow plays a role in bringing about Alzheimer’s disease.

Scientists have known for more than 15 years that the ApoE-4 gene is a player in Alzheimer’s disease, but the idea that it works in concert with the herpes virus is new, according to Federoff.

This work raises the question whether herpes in concert with ApoE-4 increases the risk of Alzheimer’s disease. The data suggests that ApoE-4 may support the ability of herpes simplex 1 to be a more virulent pathogen, says Federoff.

Herpes simplex 1 infects more than 80 percent of Americans and causes cold sores around the mouth. The findings, published online in the journal Neurobiology of Aging, shows that the particular form of the gene that puts people at risk also creates a fertile environment for herpes in the brain, allowing the virus to be more active than other forms of the ApoE gene.