Study Finds Link Between Shingles and Elevated Risk of Strokes

Herpes zoster can increase the risk of stroke, especially among patients under 40 years of age, for whom the vaccine is not typically recommended.

Patients with herpes zoster (HZ), or shingles, have a higher risk of stroke because of lipid vesicles called exosomes, which shuttle proteins and genetic information between cells, according to new research from the University of Colorado Anschutz Medical Campus.

The objective of the study was to detail the mechanisms behind the link between shingles and strokes.

“Most people know about the painful rash associated with shingles, but they may not know that the risk of stroke is elevated for a year after infection,” said the study’s lead author Andrew Bubak, PhD, assistant research professor in the Department of Neurology at the University of Colorado School of Medicine, in a press release. “Importantly, the rash is often completely healed and individuals feel normal but nonetheless are walking around with this significant elevation in stroke risk.”

HZ is caused by the varicella zoster virus, which leads to chickenpox, and the virus can reactivate later in life and cause even more excruciating pain. However, prior research indicates that HZ can also elevate the risk of stroke, especially among patients under 40 years of age, for whom the HZ vaccine is not typically recommended.

The investigators sought to better understand this association by doing a deeper examination of exosomes.

“Exosomes carry pathogenic cargo that can cause thrombosis and inflammation distant from site of actual infection,” Bubak said. “That could ultimately lead to a stroke in patients.”

The researchers collected plasma samples from 13 patients with HZ and 10 without to extract exosomes from the plasma. The samples were gathered at the time of infection and at 3-month follow-ups for a subset of patients.

The investigators found prothrombotic exosomes, which may cause blood clots, present in patients with HZ. At the 3-month follow-up, they found proinflammatory exosomes, which also carry a risk for stroke.

The findings suggest that in a subset of people with HZ, the virus may not return to latency or the circulating exosomes that cause a prolonged prothrombotic state may persist following therapy, according to the study. Bubak added that using antiviral agents longer with the addition of antiplatelet and anti-inflammatory agents could help.

“As well as initiatives to increase HZ vaccine uptake to decrease stroke risk, particularly in individuals with known preexisting stroke risk factors,” Bubak said in a press release. “If these findings are confirmed with a larger longitudinal study, then this could change clinical practice.”

Further, the study authors said that most physicians are unaware of the connection between HZ and stroke.

“But it’s really important and so easily mitigated,” Bubak said in a press release. “Send them home with antiplatelet agents.”

REFERENCE

Researchers Reveal Why Shingles Can Cause Strokes. University of Colorado Anschutz Medical Campus. October 27, 2022. Accessed October 31, 2022. https://news.cuanschutz.edu/news-stories/researchers-reveal-why-shingles-can-cause-strokes