A new paradigm in ulcerative colitis: Regulatory T cells are key factor which induces/exacerbates UC through an immune imbalance

• DOI: 10.1016/j.molimm.2012.11.015
• Publication Date: 2012-12-29T19:49:14Z
• Authors: Hiroyuki Hanai; Takayuki Iida; Kentaro Ikeya; Jinrou Abe; Yasuhiko Maruyama; Teruyuki Shimura; Ken Sugimoto; Fumitoshi Watanabe
• Keywords: Adult; Male; 0303 health sciences; Adolescent; Down-Regulation; Middle Aged; Lymphocyte Activation; Severity of Illness Index; T-Lymphocytes, Regulatory; Young Adult; 03 medical and health sciences; T-Lymphocyte Subsets; Humans; Colitis, Ulcerative; Female; Leukapheresis; Lymphocyte Count; Immunologic Memory

Leukocytapheresis (LCAP) appears to remove or inactivate inflammatory cells and to reset immunological responses, resulting to cure responders of ulcerative colitis (UC). The changes of T cell subsets were investigated in UC patients treated with LCAP. Levels of T cell subsets in peripheral blood before and after LCAP were analysed by flow cytometric analysis. Of 20 UC patients, 13 (65%) achieved remission and 2 (10%) showed the improvement of UC symptoms. Ratios of some T cell subtypes such as regulatory T (Treg) cells and memory T cells to CD4(+) T cells changed significantly only in responders. Especially, ratio of resting Treg/CD4(+) T cells was significantly increased after the first LCAP session, and then one of activated Treg/CD4(+) T cells was increased after 2 week. This may lead to the development of a new UC paradigm in which an imbalance in Treg cell subsets triggers the onset and/or exacerbation of UC.