Respiratory syncytial virus (RSV) is the leading cause of hospitalization in young children due to respiratory complications such as bronchiolitis and pneumonia. However, little is known about why some children develop only mild symptoms while others develop severe disease. To better understand what happens in these cases, clinical scientists at Brigham and Women’s Hospital, a founding member of the Mass General Brigham healthcare system, and Boston Children’s Hospital analyzed samples of patients’ airways and blood and found distinct changes in children with severe cases. of RSV, including an increase in the number of natural killer (NK) cells in the airways. Descriptive study, which focuses on understanding the underpinnings of severe disease, can help lay the foundation for identifying new targets for future treatments. The results are published in Scientific translational medicine.
“As a doctor, I help care for children who have the most severe symptoms, and as a researcher, I am motivated to understand why they get so sick,” said corresponding author Melody G. Duvall, MD, PhD, of the Division of Pulmonary Medicine. and Critical Care Medicine at Brigham and Women’s Hospital (BWH) and the Division of Critical Care Medicine at Boston Children’s Hospital. “NK cells are important first responders during viral infection, but they can also contribute to lung inflammation. Interestingly, our findings are consistent with data from some studies on COVID-19, which reported that patients with the most severe symptoms also “They had increased NK cells in their airways, along with previous studies, our data links NK cells to severe viral diseases, suggesting that these cellular pathways deserve further investigation.”
Duvall and colleagues, including senior author Roisin B. Reilly of BWH’s Division of Pulmonary and Critical Care Medicine, looked at samples from 47 critically ill children with RSV, analyzing immune cells found in their airways and peripheral blood. Compared with uninfected children, those with severe disease had elevated levels of NK cells in the airways and decreased NK cells in the blood. Furthermore, they discovered that the cells themselves were altered, both in appearance and in their ability to perform their immunological function of killing diseased cells.
Duvall and co-authors previously described a post-pandemic increase in pediatric RSV infections. While doctors can only provide supportive care to the most seriously ill children, vaccines to prevent RSV are now available for children 19 months and younger, adults 60 years and older, and pregnant people.