Elevated levels of IL-2 and IL-21 produced by CD4+ T cells in inflammatory bowel disease.

CD4+ T cells are considered as a subset of cells that play a pivotal role in the development of inflammatory bowel disease (IBD). The aim of this study was to assess the levels of interleukin (IL)-2, IL-21 and their receptors produced by CD4+ T cells in patients with inflammatory bowel disease. Thirty-two patients with ulcerative colitis (UC) and mean age of 37.93±10.37 years, as well as 22 patients with Crohn’s disease (CD) and mean age of 37.04±10.44 years, were studied. The healthy controls (HC) included 31 subjects with a mean age of 36.7±10.48 years. Peripheral blood mononuclear cells (PBMCs) were isolated from all the participants. The CD4+ T cells were isolated and the expression of IL-2 and IL-21 and also their receptors were examined by flow cytometry. The level of IL-2+ cells was significantly increased in UC patients compared with HC (40.71±6.04 vs 37.24±6.54, respectively, p=0.04). The level of IL-21+ cells was also significantly elevated in CD patients compared with HC (4.44±1 vs 3.83±0.74, respectively, p=0.02). Furthermore, we found a significant positive correlation between clinical activity index (CAI) and IL-21+ cells. According to the results, we hypothesize that the elevated level of IL-2+ and IL-21+ T cells and a positive correlation between IL-21+ cells with CAI in UC patients may contribute to the pathogenesis of disease. Moreover, the assessment of cells producing such cytokines constitutes a potential diagnostic and therapeutic strategy for IBD.

Evaluation of CD4+ CD25+ FoxP3+ regulatory T cells during treatment of patients with brucellosis.

Cell-mediated immunity (CMI) plays a critical role in the control of brucellosis. Regulatory T cells (Tregs) have a functional character in modulating the balance between host immune response and tolerance, which can eventually lead to chronic infection or relapse. The aim of this study was to assess the alteration of Tregs in cases of brucellosis before and after treatment. Thirty cases of acute brucellosis with the mean age of 41.03±15.15 years (case group) and 30 healthy persons with the mean age of 40.63±13.95 years (control group) were selected and assessed. Peripheral blood mononuclear cells (PBMCs) were isolated from peripheral blood of all individuals. We analyzed the alteration of Treg cell count using flow cytometry for CD4, CD25, and FoxP3 markers. The level of CD4+ CD25+ FoxP3+ Treg cells was increased in active patients compared with controls (2.5±0.99% vs 1.6±0.84%, p= 0.0004), but it had declined in the treated cases (1.83±0.73%, p=0.02). The level of Tregs was elevated in three relapsed cases. The frequency of Tregs and Treg/Teff (effector T cell) ratio was correlated with inverse serum agglutination test (SAT) and, 2-mercaptoethanol (2-ME) titers as markers of treatment in brucellosis. Based on our findings, we suggest that regulatory cells, such as CD4+ CD25+ FoxP3+ Treg cells, may contribute to the development of infection processes involving immune responses in brucellosis, and evaluation of regulatory T-cell levels may be a potential diagnostic strategy for the treatment outcome in chronic and relapsed cases of brucellosis.