Ohio State researchers tested genetically engineered mice with the flu virus to gauge the relationship between a genetic mutation and heart issues. Credit: Courtesy of TNS

New rodent research at Ohio State suggests a correlation between a gene mutation and potential flu fatalities.

Researchers in the College of Medicine found a mutation that creates a greater risk for contracting influenza, and by injecting mice with the flu virus, they found a connection between the mutation and heart complications, which could impact the care of flu patients in the future.

According to a 2018 study from the Centers for Disease Control and Prevention, about 8 percent of U.S. residents catch the flu each year, and depending on the severity of the virus that season, between 12,000 and 79,000 people will die from complications each year.

The researchers collaborated with the Ohio State Genetically Engineered Mouse Modeling core facility to modify some of the mice to have the IFITM3 gene mutation — “knockout” mice — to then inject them with the flu, Adam Kenney, lead author of the study, said.

The mutation slows down the production of a protein that prevents the virus from entering a person’s cells, Jacob Yount, senior author of the study, said, and the mice used in this study had that mutation in order to gauge the impact.

“Up until we developed the knockout mouse, there wasn’t a good study using a mouse model in cardiathoic pathology to flu,” Kenney said.

Yount said the results showed that when the protein wasn’t present, the virus could get to the heart much easier.

“There was so much virus in the heart, so that tells us when this protein is missing, the virus can easily disseminate and replicate in the heart,” Yount said. “That high virus in the heart causes electrical dysfunction and fibrosis, which is scarring of the heart.”

Kenney said he used three different strains of the virus ranging from most to least severe. The most severe virus killed all the mice, and the least showed no virus in the heart, but Kenney said people can be exposed to any of these strains.

There hasn’t been much research before this study showing a connection between the flu and heart complications, Kenney said, but Yount said the mutation is not uncommon: About 20 percent of Chinese people and about 4 percent of Europeans have it.

There are currently no clinical tests to see if one has this IFITM3 mutation, but eventually tests will be developed along with the research of possible treatment options, Yount said.

“This research highlights why everybody should be vaccinated,” Yount said. “You’re not only protecting yourself from the flu but less likely that you’ll transmit the flu to people who are really susceptible.”