IFN-γ CA microsatellite polymorphism is associated with susceptibility to respiratory syncytial virus Infection and severity.

AIM: IFN-γ, an essential cytokine in the viral cell-mediated immune response, has been associated with the pathogenesis of respiratory syncytial virus (RSV) bronchiolitis and to the severity of the infection. The aim of this study was to investigate whether IFN-γ CA microsatellite (rs3138557) polymorphism was associated with susceptibility to RSV in Chinese Han children and with the severity of the infection.
METHODS: The IFN-γ CA microsatellite was tested in 218 RSV bronchiolitis inpatients and 303 healthy controls, and the severity of the RSV bronchiolitis was evaluated using a standardised respiratory scoring system.
RESULTS: The frequencies of CA12+/CA12+, CA12+/CA12- and CA12-/CA12- in the 218 RSV bronchiolitis patients and 303 controls were approximately 11% versus 19%, 55% versus 53% and 34% versus 28%, respectively. The gene polymorphism of IFN-γ CA repeats between the two groups was statistically different. The clinical respiratory scores of RSV bronchiolitis cases with CA12+/CA12+ and CA12+/CA12- were 2.84 ± 0.40 (SD) and 2.95 ± 0.44 (SD), respectively, and these were significantly lower than the 3.1 ± 0.36 (SD) score for those with CA12-/CA12-.
CONCLUSION: IFN-γ CA microsatellite polymorphism was associated with the susceptibility of Chinese Han children to RSV and the severity of the infection. ©2014 Foundation Acta Paediatrica. Published by John Wiley & Sons Ltd.