Abstract: AIM: To approach the effects of Bacille Calmette-Guerin(BCG) on immunological function of infants with bronchiolitis in vitro. METHODS: The monocytes were segregated from the peripheral blood of infants with acute bronchiolitis and healthy infants as control.The cytokines of IL-10 and IL-12 were measured by ELISA after interfered with different concentrations of BCG in vitro.IL-4, produced by lymphocytes treated with the cultural supernatant of BCG-stimulated monocytes were determined by ELISA.Acute bronchiolitis infants and health children treated with normal saline were as control. RESULTS: BCG stimulated IL-10 and IL-12 production in a dose response manner in a certain concentration range.The higher level of IL-10 was observed when BCG concentration reached 50 μL mL, while IL-12 had no significant increase.The level of IL-4 was markedly decreased compared with pre-treatment (P<0.05). CONCLUSION: Proper concentrations of BCG could induce a TH1 cytokine response effectively, the level of IL-4 was degraded after BCG intervention, presuming concerned with regular T cells(CD4 +CD25 +Tr) induced by IL-10.

Key words: bronchiolitis, Bacille Calmette-Guerin, IL-4, IL-10, IL-12