[Imbalance of CD4(+) T cell subgroups in ulcerative colitis].

Objective To investigate the relationship of the imbalance of CD4+T cell subgroups and the pathogenesis of ulcerative colitis (UC).Methods Peripheral blood samples were collected from 24 UC patients and 17 healthy donors.Then the phenotype of CD4+T cells and the major transcription factor expression of each subset were analyzed by flow cytometry and real-time PCR (polymerase chain reaction) respectively.The serum concentrations of major cytokines of each subgroup were measured by cytometric bead array (CBA) and ELISA (enzyme-linked immunosorbent assay).Results (1) The proportion of Treg cells in the UC group was lower than the control group (6.7%±1.7% vs 7.9%±1.4%, P=0.016), especially in active stage (6.4%±1.7%, P=0.005). As compared with the control group, the expression of FOXP3 mRNA was lower in the UC Group (P=0.020). And so was the serum concentration of TGF-β1 [(21±8) μg/L vs (28±7) μg/L, P=0.026].(2)There were no significant differences in Th1-related transcription factors and cytokines between two groups.(3) Th2 cells were higher in the UC group (2.7%±1.1% vs 1.6%±0.4%, P=0.002), especially in active stage (2.8%±1.0%, P=0.001).The expression of GATA-3 mRNA was 4.4 folds higher than that of the controls (P=0.045).(4) Th17 cells were higher in the UC group (3.4%±1.8% vs 1.8%±0.7%, P=0.005). And the RORγt mRNA expression was 13 folds higher in UC group (P=0.001); the serum concentrations of IL-6 and IL-17 were higher in the UC group (both P<0.05). (5) The ratios of Treg/Th2 and Treg/Th17 were significantly lower in the UC group and associated with disease activity (both P<0.05).Conclusion The imbalances of Th2, Treg and Th17 subgroups may play pivotal roles in the pathogenesis of UC. Key words: Colitis,ulcerative;  CD4-positive T-lymphocytes;  Immunity