Comparison of cytokine expression profiles in infants with a rhinovirus induced lower respiratory tract infection with or without wheezing: a comparison with respiratory syncytial virus

Roh, Da Eun; Park, Sook-Hyun; Choi, Hee Joung; Kim, Yeo Hyang

IL-10 is an anti-inflammatory cytokine whose immunomodulatory action is well-known 19) . In our previous pediatric study, IL-10 levels were significantly higher in H1N1 patients infected in 2009 who presented with severe pneumonia in comparison to mild pneumonia 20) . These findings may suggest that because of the anti-inflam matory and immunomodulatory properties of IL-10, elevated IL-10 levels present in severe disease may have additional effects that aid in the control of the disease. Similar to H1N1 infection, in previous study regarding cytokine gene expression in the induced sputum from children with virus induced acute asthma, it was demonstrated that IL-10 mRNA was increased in virus induced acute asthma, which was reduced upon the recovery phase 21) . During RSV induced inflammation, especially severe RSV infection, Th2-, Th9-, and Th17-related cytokines are elevated. Murine studies presented that the combined actions of regulatory factors such as CD4 regulatory T cells and IL-10 inhibits the inflammatory cytokine response and limit RSV-induced disease 22) . Another study also demonstrated that the IL-10 level was higher in the acute phase than the convalescent phase in both RV and RSV infections, which was significantly different in comparison to the control group 14) . The increased IL-10 level found during an acute viral infection may suggest resolution of the inflammatory process. There is evidence that patients with a decreased IL-10 response could have a greater inflammatory response to viral infections and an increased risk for recurrent wheezing 23, 24) .