文本框: STUDY ON SINGLE-CELL LEVEL OF TH1/TH2 BALANCE TREATED BY BCG-PSN IN ASTHMATIC CHILDREN Shao J, Zhao J-Q, Xia Z-W, Wang Y-Z Pediatric Department, Ruijin Hospital, Shanghai 2nd Medical University, China Objective: To investigate the influence of BCG-PSN (polysaccharide nucleic acid fraction of Bacillus-Calmette-Guerin, BCG-PSN) on Th1/Th2 balance, and evaluate its non-specific modulates effect on asthma airway inflammation. Methods: 45 asthmatic children accepted one course BCG-PSN treatment was involved in the study. Peripheral blood was collected before and after treatment and analyzed intracellular cytokines (IFN-γ, IL-4) and surface antigens (CD3, CD4, CD8) of T cells by three-color flow cytometric method. Results: Significant lower frequencies of CD4+ IL-4+ were found after one –course treatment of BCG-PSN compared with pre-treatment (3.21±2.51%, vs. 0.75±0.85%, u=5..33, p<0.05), no significant difference of CD4+IFN-γ+ were found between pre- and post-treatment (18.9±9.12%, vs. 44.22±39.00, u=5.07, p<0.05). but the ratio of IFN-γ+/IL-4+ also showed significant difference compared with pre-treatment (11.46±9.53 vs 44.22±39.00, u=5.07, p<0.01). Conclusion: BCG-PSN could inhabit Th cells secrete IL-4, thus promote the shift of Th1/Th2 balance toward Th1 cytokines, which will be probably benefit to asthma long-term stable. [Key words] asthma, Th1, Th2, Bacillus-Calmette-Guerin 0724