The levels of interferon-γ( IFN-γ), interleukin-2 ( IL-2) and interleukin-4 were evaluated by enzyme linked immunosorbent assay ( ELISA), which implied Th1/ Th2 balance. 酶联免疫吸附法(ELISA)法检测细胞因子干扰素-γ(IFN-γ)、白细胞介素-2(IL-2)和白细胞介素-4(IL-4)水平,以了解Th1与Th2的平衡关系。