Relationship Between Peripheral Leukocyte Function Associated Antigen-1(LFA-1) And Regulatory T Cells, Th17Cells, And Disease Activity In Patient With Inflammatory Bowel Disease

Background:Inflammatory bowel disease (IBD) are complex disorders resulting from aberrant immune response. The loss of homeostasis between CD4+CD25+Foxp3+regulatory cells (Treg) and proinflammatory Th17cells, and the abnormal function and quantity of leukocyte function associated antigen-1(LFA-1) are presumed to play a pivotal role in the pathogenesis of IBD.Aims:To investigate the proportion of peripheral Treg cells, Th17cells and the relative expression level of LFA-1in patients with IBD and their pathogenic mechanism.Methods:Twenty healthy controls and115IBD patients, including83Crohn’s disease (CD) and32ulcerative colitis (UC), were enrolled in this study. The proportion of peripheral Treg and Thl7cells, and the percentage and mean fluorescence intensity (MFI) of LFA-1was detected by flow cytometry. The expression of Foxp3mRNA, RORγ t mRNA and LFA-1mRNA in the peripheral blood mononuclear cells (PBMC) was assessed by real-time PCR. Results:The proportion of peripheral Treg cells and the expression of Foxp3mRNA,LFA-1mRNA were significantly lower in IBD patients than that in normal controls. There were also significant differences between remission group and acticity groups (P<0.05). The proportion of peripheral Thl7cells and the expression of ROR γ t mRNA were significantly higher in IBD patients than that in normal controls. MFI of LFA-1in Th17cells in CD and UC patients’ was significantly lower than that in normal controls (P<0.05). The ratio of Treg and Thl7in active CD was significantly higher than that in remission CD (P<0.05). MFI of LFA-1in patients using immunosuppressive agents was significantly lower than those without immunosuppressive agents (P<0.05). Negative correlation was found among Treg and CDAI, CAI, ESR or CRP, while positive correlation was found between Th17cells and these indicators (P<0.05). There was a positive correlation not only between CDAI and ESR, CRP or PLT, but also between ESR, CRP and CAI (P<0.05). Negative correlation was found not only between CDAI and HCT, Hb, ALB, AST, but also between CAI and HCT, Hb, ALB (P<0.05).Conclusions:The results indicated that Treg cells,Th17cells and LFA-1participate in the initiation and development of IBD. The decreased expression of LFA-1mRNA may be the precursor of the reduction of Treg cells and it might provide the basis for predicting disease recurrence of IBD.