OBJECTIVE: To investigate the compositions of Th1/Th2/Th3 cells in chronic hepatitis B virus (HBV)-infected individuals by determining the expression of interleukin-4 (IL-4), inetrferon-gamma (IFN-gamma), and transform growth factor-beta (TGF-beta) in single CD4(+) T cells isolated from peripheral blood mononuclear cells (PBMCs) and the role of polarized Th cell populations in chronic HBV-infection was discussed. METHODS: PBMCs from chronically infected HBV individuals were isolated, stimulated by PMA/Ionomycin/Monensin, and IL-4, IFN-gamma and TGF-beta production by CD4(+) T cells was determined by using fluorescence activated cell sorter (FACS) analysis. RESULTS: The percentage of IFN-gamma-producing T cells, IL-4-producing T cells and TGF-beta-producing T cells ranged from 2.3% - 18.6%, 1.1% - 8.7% and 0.7% - 7.1% respectively in CD4(+) T cells from non-infected individuals. Most of CD4(+) T cells from PBMCs in chronically infected HBV individuals were Th0 cells. The proportion of Th1 cells increased significantly with hepatic inflammatory activity, and in the active period of chronic hepatitis B infection were higher than those in the non-active period (P 0.05), but were higher than that from controls (P
