Two drugs used to treat asthma and allergies may offer a way to prevent a form of pneumonia that can kill up to 40% of people who contract it, according to researchers at the University of Virginia School of Medicine. Their findings were published in PLoS Pathogens.
Influenza pneumonia results when a flu infection spreads to alveolar air sacs deep within the lungs. Normally, a flu infection does not progress that far into the lower respiratory tract (LRT), but when it does, the results can be deadly.
The new research suggests that early administration of two asthma drugs––zafirlukast (Accolate, AstraZeneca) and montelukast (Singulair, Merck)––could prevent the infection of alveolar cells deep in the LRT.
“When we look at pandemic strains of influenza that have high mortality rates, one of the best adaptations of those pandemic viruses is their ability to infect these alveolar epithelial cells,” researcher Amber Cardani explained. “It’s one of the hallmarks for certain strains that cause the lethality in these pandemics.”
The researchers determined that alveolar epithelial cells are typically protected from influenza infection by alveolar macrophages, a type of immune cell. In some cases, however, the flu virus can prevent the macrophages from performing their protective function, allowing the epithelial cells to become vulnerable to infection.
“It’s not as though they lack alveolar macrophages; it’s just that their alveolar macrophages don’t work right when they get exposed to the flu,” said lead investigator Dr. Thomas J. Braciale. “And those are the types of patients, who potentially would eventually go to the intensive care unit, that we think could be treated early in infection with Accolate or Singulair to prevent infection of these epithelial cells and prevent lethal infection.”
For their next steps, the researchers are consulting with colleagues to determine whether patients being treated with zafirlukast and montelukast are less likely to develop influenza pneumonia during flu outbreaks.
Source: University of Virginia; February 21, 2017.