A significant proportion of hospitalized patients with influenza develop complications of acute respiratory distress syndrome, driven by virus-induced cytopathic effects as well as exaggerated host immune response. Reporting in The American Journal of Pathology, published by Elsevier, investigators have found that treatment with an immune receptor blocker in combination with an antiviral agent markedly improves survival of mice infected with lethal influenza and reduces lung pathology in swine-influenza-infected piglets. Their research also provides insights into the optimal timing of treatment to prevent acute lung injury.
Previously, the investigators found that an excessive influx of neutrophils, infection fighting immune cells, and the networks they create to kill pathogens, known as neutrophil extracellular traps (NETs), contribute to acute lung injury in influenza infection. Formation of NETs by activated neutrophils occurs via a cell death mechanism called NETosis and the released NETs contain chromatin fibers that harbor toxic components.