Effects Of Oral Bacillus Calmette-Guerin On Th1/Th2 Balance In Asthmatic Patients

Objective:To explore the effect of oral Bacillus Calmette-Guerin on Th1/Th2 balance in asthmatic patients .Methods: Forty-six mild and moderate asthma patients were randomly divided into two groups: common group,oral BCG group . The ptatients in the oral BCG were treated with BCG and bronchodilators ,while the common group was given only bronchodilators,and choose 20 healthy adults as the control group.Expiratory volume in one second (FEV1) and purified protein derivative(PPD)skin test was measured and serum concentrations of IL-4 and IFN-γwere detected before and after treatment. The intracellular expressions of IFN-γand IL-4 in Th1/ Th2 cell and Th1/Th2 rate were assayed by flowcytometry.To detect adverse reaction.Results: There was no significant difference on FEV1 in common group and oral BCG group between before and after treatment (P >0.05).There was no differernce on the score of the evaluation to the symptoms of asthma in the common group between before treatment and after treatment(P >0.05),whil the score of the evaluation to the symptoms of asthma in the oral group have significant difference(P<0.05).Compare wth after treatment oral group and common group,the seroconversion rate in oral group achieve statistical significance. Compared with the control group, asthmatic human has higher IL-4 level and lower IFN-γlevel in the blood plasm.Afer treatment oral group has higher IFN-γlevel and lower IL-4 level than common group.In oral BCG group and common group ,the IFN-γexpression of Th1 cell and Th1/Th2 rate before treatment were lower than those in control goup,while the IL-4 expression of Th2 cell was higher than that in control group(P<0.01). The IL-4 expression of Th2 cell and the IFN-γexpression of Th1 cell in the common group were not achieve statistical significance before and after treament(P >0.05).The IFN-γexpression of Th1 cell in the oral BCG group after treatment were (17.48±9.78)% which was higher than that of (10.79±9.79)% before treatment(P<0.05). The IL-4 expression of Th2 cell in the oral BCG group after treatment were (8.75±8.2)% which was lower than that of (4.45±8.1)% before treatment (P<0.05).There are no adverse effects obviously for oral BCG.Conclusion: The immune imbalance of Th1/Th2 is a important role in asthmatic morbidity mechanism.Oral BCG have manipulation simpler,convenient,little adverse reaction of advantages.Oral BCG may inhibit Th2 cell activation and could correct the imbalance of Th1/Th2 .