title: Elevated expression of interleukin-21 and its correlation to T-cell subpopulation in patients with ulcerative colitis.
abstract: OBJECTIVE
  To investigate the expression of interleukin-21 (IL-21) and its correlation to T-cell subpopulation including Th1, Tc1 and Th17 cells in Ulcerative colitis (UC).
  
  
  METHODS
  We examined the expression of IL-21, IL-17 and IFN-γ in UC patients and controls by enzyme-linked immunosorbent assay (ELISA) and flow cytometry.
  
  
  RESULTS
  We found that IL-21 was expressed on CD3(+)CD8(-)T cells by flow cytometry. Plasma IL-21 level and the percentage of CD3(+)CD8(-)IL-21(+) T cells were significantly elevated in UC patients compared to controls. The percentage of CD3(+)CD8(-)IL-17(+) T (Th17), CD3(+)CD8(-)IFN-γ(+) T (Th1) and CD3(+)CD8(+) IFN-γ(+) T (Tc1) cells was also significantly increased in UC patients. Moreover, we found a significant positive correlation between CD3(+)CD8(-)IL-21(+)T cells and Th17 cells.
  
  
  CONCLUSIONS
  Elevated IL-21 and its positive correlation to Th17 cells may play a role in the pathogenesis of UC.
authors.affiliation: Department of Gastroenterology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Ge
authors.affiliation: Department of Gastroenterology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.
authors.forename: Xiaohua
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Gastroenterology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Gastroenterology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.
authors.forename: Zhenmei
authors.initials: Z
authors.lastname: Fu
authors.affiliation: Department of Gastroenterology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.
authors.forename: Xiuju
authors.initials: X
authors.lastname: Shi
authors.affiliation: Department of Clinical Laboratory, Zhangqiu People's Hospital, Jinan, Shandong, China.
authors.forename: Qingyan
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Gastroenterology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.
authors.forename: Jiyong
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Gastroenterology, Shandong Provincial Hospital Affiliated to Shandong University, Jinan, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhu
keywords: T helper 1; T helper 17; interleukin-21; ulcerative colitis