Clinical study on transcutaneous inoculation of inactivated bacillus calmette-guerin in preventing children with bronchiolitis from asthma

Objective:By evaluating the effects of transcutaneous inoculation of inactivated bacillus calmette-guerin (BCG) in preventing children with bronchiolitis from asthma to explore its mechanism.Methods:85 children with bronchiolitis were randomly divided into routine treatment group (routine group) and inactivated BCG group (routine therapy adjuvant inoculation of inactivated BCG). The changes of IFN-γ, IL-4 and IgE before treatment and half a year after treatment of children with bronchiolitis were observed and they were followed-up for two years to count the incidence of asthma in children aged three years old. Moreover 20 healthy children were as normal controls.Results:①IL-4 and IgE levels before treatment in BCG group and routine group were higher than those of control group, but IFN-γ levels were lower than that of control group with significant difference ( P 0.01). There was not significant difference between BCG group and routine group ( P 0.05). ②In BCG group, IL-4 and IgE levels after treatment were lower than those before treatment, but IFN-γ levels after treatment were higher than that before treatment ( P 0.01), and there was no significant difference in IFN-γ levels comparing to that of control group ( P 0.05). In routine group, there were no significant differences in IL-4 and IgE levels before and after treatment, but IFN-γ after treatment significantly decreased ( P 0.01). ③Incidence of asthma in children aged 3-year old in BCG group were significantly lower than that of routine group (8.89% vs 42.5%, P 0.005).Conclusion:Inactive BCG could stimulate the production of IFN-γ in Children with bronchiolitis, down-regulate IL-4 levels, induce the dominant differentiation of Th1/Th2 and reduce the incidence.