Late-breaking abstract: IFN-gamma CA microsatellite polymorphism is associated with the susceptibility and severity to respiratory syncytial virus infection

Aim: To investigate the relationship between the polymorphism of CA microsatellite(rs3138557) in IFNgamma gene and theseverity to respiratory syncytial virus (RSV) infection. Methods: The IFNgamma CA microsatellite was tested in 218 RSV bronchiolitis inpatients and 303 healthy children as control. The severity of RSV bronchiolitis was evaluated by standardized respiratory scoring system Results: (1) The frequencies of CA12+/CA12+, CA12+/CA12- and CA12-/CA12- in the RSV bronchiolitis group were11%, 55.05% and35.95% respectively. The frequencies in the control group were19.47%, 52.81% and 27.72% respectively. The gene polymorphism of IFN gamma CA repeats between both groups was statistically different (P = 0.024). (2) The clinical respiratory scores of RSV bronchiolitis cases with CA12+/CA12+, CA12+/CA12- were 2.84 plusmn 0.41; 2.95plusmn0.44 respectively. These scores were lower than those with CA12-/CA12- (3.10plusmn0.36).(P=0.004; P=0.027). Conclusion: The polymorphism of IFN gamma CA microsatellite is associated with the susceptibility and severity of RSV infection in Chinese Han children. Key words: IFNgamma , gene polymorphism, CA microsatellite , RSV bronchiolitis