Methods: 128 nasopharyngeal aspirate specimens were collected from 128 pediatric patients hospitalized with acute respiratory infection including wheezing and tested for 7 common respiratory viruses. They were divided into HMPV (n=27) and RSV groups (n=101). Th1(IFN-γ), Th2(IL-4, IL-13) and Th17(IL-1β) cytokine profiles were analyzed.
Results: IFN-γ levels in the 2 groups were statistically similar (P=0.08). IL-4 levels were significantly higher in the RSV compared to HMPV group (P<0.0001). IL-13 levels in both groups were under detection level. IL-1β levels were significantly higher in the HMPV compared to the RSV group (P<0.0001).
Conclusion: Our results suggest that HMPV and RSV have different inflammatory mechanisms. HMPV induces airway inflammation by the Th17 pathway through release of IL-1β, whereas RSV acts through the Th2 pathway.