Respiratory syncytial virus (RSV) is a common cause of hospitalization in young children, leading to respiratory issues like bronchiolitis and pneumonia. However, little is known about why some children develop mild symptoms while others experience severe disease. To shed light on this, researchers from Brigham and Women’s Hospital and Boston Children’s Hospital studied samples from patients with severe RSV, finding distinct changes in their airways and blood, such as an increase in natural killer (NK) cells. This study, published in Science Translational Medicine, aims to uncover the underlying mechanisms of severe RSV illness and potentially identify new targets for treatment.
Lead author Melody G. Duvall, MD, PhD, explained that as both a physician and researcher, she is compelled to understand why some children develop severe symptoms. NK cells play a crucial role in responding to viral infections, but they can also contribute to lung inflammation. Interestingly, the findings of this study align with research on COVID-19, where patients with severe symptoms also had increased NK cells in their airways. This connection suggests that investigating cellular pathways involving NK cells could provide valuable insights into serious viral illnesses.
In their analysis of samples from 47 severely ill children with RSV, Duvall and her team discovered elevated levels of NK cells in the airways of these patients, along with a decrease in NK cells in their blood. The researchers also observed changes in the appearance and function of these cells, affecting their ability to kill diseased cells effectively. These findings provide important insights into the immune response during severe RSV infections and could pave the way for new treatment strategies.
Previous research by Duvall and her colleagues has highlighted a rise in pediatric RSV infections post-pandemic, underscoring the importance of understanding and addressing this respiratory virus. While supportive care is currently the primary treatment for severely ill children with RSV, preventive measures like vaccines are available for children under 19 months, adults over 60, and pregnant individuals. By expanding our knowledge of RSV infections and immune responses, researchers hope to improve outcomes for children with severe RSV and develop more effective prevention and treatment options in the future.