Objective To investigate the changes in the levels of interleukin-17(IL-17) and transforming growth factor beta 1(TGF-β1) in serum and bronchoalveolar lavage fluid(BALF) and their clinical significance among children with asthma.Methods Fifty-six children with asthma were divided into moderate or severe asthma(n=37) and mild asthma groups(n=19) and 18 children without asthma were selected as the control group.Cells in BALF were counted under a microscope.The levels of IL-17 and TGF-β1 in serum and BALF were...