New evidence for viruses’ role in Alzheimer’s disease21st June 2018 by Katherine Lindemann
Herpes genes found in patients’ brains provide unprecedented evidence for a connection, but the viruses’ exact role remains unclear.https://www.researchgate.net/blog/post/new-evidence-for-viruses-role-in-alzheimersResults of a recent study breathe new life into an old hypothesis: that viruses, herpesviruses in particular, could play a role in Alzheimer's disease. Researchers analyzed DNA and RNA sequencing data from brain tissue donated by 622 people who had Alzheimer’s disease and 322 people who didn’t. They found that specific herpesviruses were more abundant in the brains of patients who had Alzheimer’s when they died. For two of the viruses, HHV-6A and HHV-7, the association with Alzheimer’s was particularly strong, even when compared to tissue samples of people with other neurodegenerative diseases.
The idea that viruses could somehow be involved in Alzheimer’s isn’t new. Previous studies have examined HSV-1, the virus that causes cold sores, but this evidence was less compelling. “Earlier studies focused on the presence of anti-HSV-1 antibodies, which meant that those with antibodies had encountered HSV-1 at some time during their lives. This new study showed HH-V6 and HHV-7 viral genes in the brains of Alzheimer’s disease patients at the time they died,†explains Sam Gandy, an Alzheimer’s disease specialist at the Ichan School of Medicine at Mount Sinai and one of the study’s senior authors.
The study’s authors hadn’t set out looking for viral genes. They’d originally hoped to find ways to repurpose existing drugs to treat Alzheimer’s. “We didn’t go looking for viruses, but viruses sort of screamed out at us,†said Ben Readhead, the study’s lead author. Surprised by what they’d found in the Mount Sinai Brain Bank samples, they turned to other brain banks to test additional samples. The same patterns were detected in samples from all the banks.
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