The role of IL-17A/IL-17RA and lung injuries in children with lethal non-pandemic acute viral pneumonia

This study aimed to evaluate IL-17A (interleukin 17A) and IL-17RA (IL-17A receptor) in a pediatric population that died with non-pandemic acute viral pneumonia compared to the non-viral pneumonia group. Necropsy lung samples (n = 193) from children that died after severe acute infection pneumonia were selected and processed for viral antigen detection by immunohistochemistry. After this, they were separated into two groups: virus-positive (n = 68) and virus-negative lung samples (n = 125). Immunohistochemistry was performed to assess the presence of IL-17A and IL-17RA in the lung tissue. The virus-positive group showed stronger immunolabeling for IL-17A and IL-17RA (p = 0.020 and p < 0.001, respectively). The result of this study may suggest that IL-17A and IL-17RA plays an essential role in the maintenance of viral infection and lung injuries. These aspects may increase the severity of the inflammatory response leading to lethal lung injuries in these patients. Children with community-acquired non-pandemic pneumonia that requiring hospitalization could benefit from using IL-17RA/IL-17A monoclonal antibodies to block their injurious effects.