Herpes virus may have a connection to Alzheimer’s disease

Henrietta Brewer
June 26, 2018

Now, researchers have found that not only patients with Alzheimer's disease have an increased level of two strains of the herpes virus, but the viral genes are actively destroying the human genes, which increases the risk of dementia. The research offers compelling evidence for the idea that viruses might be involved in Alzheimer's, particularly two types of herpes that infect most people as infants and then lie dormant for years.

Some scientists have long believed that viruses play a role in the development of Alzheimer's.

But a study in 2014, published in the journal Alzheimer's Research & Therapy, found that this theory might have been wrong all along. The exposure led to a reaction in which protein fibers called amyloids, which cause the plaques found in Alzheimer's patients' brains, were formed, perhaps to ensnare the viruses as part of immune response. The new study gives "points" to this theory, and that is why it will revive the related investigations into the herpes-Alzheimer's relationship.

The researchers have clearly mentioned that there is no evidence to prove that these viruses cause Alzheimer's.

Dudley said earlier studies of viruses and Alzheimer's were indirect and correlative, but computational analysis using multiple levels of genetic information from affected brain tissue allowed the group to identify direct interaction with or coregulation of known Alzheimer's genes. Dudley is a member of the ASU-Banner Neurodegenerative Disease Research Center.

"We mapped out the social network, if you will, of which genes the viruses are friends with and who they're talking to inside the brain", Dudley told NPR, offering an analogy: "If the viruses are tweeting, who's tweeting back?" Researchers also found in the new study that the herpes virus was involved in networks that regulate the generation of amyloid proteins.

Readhead says around 90 percent of children in the US and the United Kingdom are exposed to these viruses in the first few years of life.The findings don't prove the viruses cause Alzheimer's, nor do they suggest it's contagious. It might be that viruses may in some way interact with human DNA and stimulate the growth of amyloid plaques.

"While these findings do potentially open the door for new treatment options to explore in a disease where we've had hundreds of failed trials, they don't change anything that we know about the risk and susceptibility of Alzheimer's disease or our ability to treat it today", Gandy said.

"However, if viruses or other infections are confirmed to have roles in Alzheimer's, it may enable researchers to find new antiviral or immune therapies to treat or prevent the disease", Fargo said. The data they mined is usually discarded, but was archived instead by the National Institutes of Health in a bid to accelerate the discovery of new treatments by fostering "big data" collaborations. Sam Gandy, senior author of this study and Alzheimer's disease specialist at the Ichan School of Medicine at Mount Sinai said that anti-HSV-1 antibodies have been studied in these patients earlier.

Written by Jen Christensen for CNN.

Other reports by iNewsToday