Th1 and Th2 cytokine levels in nasopharyngeal aspirates from children with human bocavirus bronchiolitis.

BACKGROUND

Human bocavirus (hBoV) is regarded as one of the possible etiologic agents in lower respiratory tract infection and bronchial asthma exacerbation in children despite frequent co-detection with other respiratory viruses. The immunologic response in children with hBoV infection is still not clear.

OBJECTIVES

To investigate the profiles of T helper-1 (Th1)/T helper-2 (Th2) cytokines in children with hBoV-associated bronchiolitis.

STUDY

DESIGN

This study utilized of 59 nasopharyngeal aspirates from 59 infants aged 24 months or younger, including 29 from children with hBoV-related bronchiolitis and 30 with respiratory syncytial virus (RSV)-related bronchiolitis. Eighteen infants hospitalized for elective surgeries were included as controls. Nasopharyngeal aspirates were tested simultaneously for cytokines interleukin (IL)-2, IL-4, IL-5, IL-10, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha using the Cytometric Bead Array.

RESULTS

Significantly higher concentrations of IFN-gamma (p=0.0001), IL-2 (0.006), and IL-4 (p=0.0002) were observed in hBoV positive specimens than in controls. The concentration of IL-10 (p=0.04) and TNF-alpha (p=0.006) in the RSV-positive group was significantly higher than in the hBoV-positive group, while there was no difference in other cytokines concentration between the two groups.

CONCLUSIONS

These results showed that both of Th1 and Th2 cytokines were increased in children with hBoV-related bronchiolitis compared to normal controls, but Th2-polarized responses were not observed.