Background/Aims: The proportions of intestinal and peripheral regulatory T cells (Tregs) in pediatric inflammatory bowel disease (IBD) were poorly investigated, as well as different subsets of these cells. Helios and Neuropilin-1 were proposed as markers differentiating between thymic and peripheral Tregs. Therefore, the aim of current work was to investigate the proportions of Tregs and expression of Helios and Neuropilin-1 in Tregs in peripheral blood and intestinal mucosa of children with inflammatory bowel disease. Materials and methods: Fifteen patients newly diagnosed with inflammatory bowel disease: ulcerative colitis (n=7) and Crohn’s disease (n=8) were included in the study. Nine children who presented with no abnormalities in colonoscopy served as a control group. Quantification of regulatory T cells of the CD4⁺CD25^highFOXP3⁺ phenotype, as well as Helios⁺ and Neuropilin-1⁺ in peripheral blood and bowel mucosa was based on multicolor flow cytometry. Results: The rates of circulating and intestinal Tregs were significantly higher in the studied group than in the control group. The rate of intestinal T regulatory lymphocytes was significantly higher than circulating Tregs in patients with IBD, but not in the control group. The median proportion of circulating FOXP3⁺Helios⁺ cells amounted to 24.83% in IBD patients and 15.93% in the controls. The median proportion of circulating FOXP3⁺Nrp-1⁺ cells was 34.23% in IBD and 21.01% in the control group. No statistically significant differences were noted for the circulating FOXP3⁺Helios⁺ cells and FOXP3⁺Nrp-1⁺ cells between the studied and the control group. Conclusion: The rates of circulating and intestinal T regulatory cells are increased in naïve pediatric patients with IBD. The rate of Tregs is higher in intestinal mucosa than in peripheral blood in patients with IBD. Flow cytometry is a valuable method assessing the composition of infiltrates in inflamed tissue. Helios and Neuropilin-1 likely cannot serve as markers to differentiate between natural and adaptive Tregs.

Background/Aims: To determine the proportion of T-regulatory cells (CD4⁺CD25^highFOXP3⁺ cells) in peripheral blood and the number of FOXP3⁺ cells in intestinal mucosa of children with inflammatory bowel disease (IBD), and to verify whether these parameters correlate with the activity of the disease. Material and methods: 24 patients newly diagnosed for IBD were included in the study: ulcerative colitis (UC; n = 13) and Crohn’s disease (CD; n = 11). Seventeen healthy controls (HC) and 16 patients with irritable bowel syndrome (IBS) served as a control group for peripheral and intestinal Tregs assessment, respectively. The disease activity was assessed by Pediatric Ulcerative Colitis Activity Index (PUCAI) and Pediatric Crohn’s Disease Activity Index (PCDAI). Quantification of regulatory T cells of CD4⁺CD25^highFOXP3⁺ phenotype in peripheral blood was based on three-color flow cytometry. Mucosal Tregs represented by FOXP3⁺ cells were evaluated using immunohistochemistry. Results: Median proportion of CD4⁺CD25^highFOXP3⁺ cells among CD4⁺ T cells in peripheral blood (5.1%, range 1.7–84% vs. 4.3%, range 2–8.1%, p = 0.023) and median number of intestinal FOXP3+ cells (115.33 per high-power field, hpf, range 39.33–375.67 vs. 10.16 per hpf, range 5–30, p = 0.0001) were significantly higher in children with IBD than in the controls. The proportion of circulating Tregs and the number of intestinal FOXP3+ cells did not correlate with clinical activity of the disease, as well as with endoscopic and histopathologic scoring. No significant correlation was found between the percentage of peripheral CD4+CD25^highFOXP3+ cells and the number of intestinal FOXP3+cells. Conclusions: Children with IBD likely do not present with a quantitative deficiency of circulating and intestinal Tregs at the moment of diagnosis.

Background Juvenile idiopathic arthritis (JIA) is a chronic, heterogenous inflammatory disease of unclear pathogenesis. JIA is hypothesized to be linked to a defective immune regulation. Anti-inflammatory cytokines belong to the best known regulatory factors. T-regulatory cells are a crucial cellular component of immune tolerance. One of their functions is synthesis of interleukin 10 (IL-10) and transforming growth factor beta1 (TGF-ß1).The aim of this study was to determine the proportion of T-regulatory cells (CD4+CD25highFOXP3+) in peripheral blood, and serum levels of TGF-ß1 and IL-10 in patients with JIA.Methods: The study included 25 patients with newly diagnosed JIA: oligoarthritis (n=17) and polyarthritis (n=8). Control group was comprised of 17 healthy children. CD4+CD25highFOXP3+ T cells in peripheral blood were quantified by means of three-color flow cytometry. Serum concentrations of TGF-ß1 and IL-10 were estimated with ELISA.Results: The proportion of peripheral CD4+CD25highFOXP3+cells in patients with JIA was significantly higher than in the controls (p=0.04). The two groups did not differ significantly in terms of their TGF-ß1 and IL-10 concentrations.Conclusions: At the time of the diagnosis, children with JIA present with elevated proportion of T-regulatory cells (CD4+CD25highFOXP3+) in peripheral blood. Anti-inflammatory cytokines, IL-10 and TGF-ß1, are not upregulated in the serum of patients with JIA, and therefore should not be considered as biomarkers of this condition.

Background: Cystic fibrosis (CF) is characterized by malnutrition and chronic inflammation predominantly occurring in lungs. Evidence suggests a relation between inflammatory activity and nutritional status. Proinflammatory cytokines, playing crucial role in pulmonary destruction in CF, are regarded as a component of the pathogenesis of illness-related malnutrition. Chemerin - a novel marker of a crosstalk between nutrition and inflammation, has not been investigated in children with cystic fibrosis. The aim of this study was to determine serum level of chemerin, interleukin-1b (IL-1b), interleukin-6 (IL-6), tumor necrosing factor α (TNF-α) and interleukin-10 (IL-10) and to verify if they correlate with the nutritional status in children with CF. Methods: The study included 72 pediatric patients with cystic fibrosis. The control group was comprised of 30 healthy children. Nutritional status parameters: Body Mass Index (BMI), fat mass percentage (FM %) and fat free mass percentage (FFM%) have been assessed in all the subjects basing on bioimpedance and anthropometry according to Slaughter. Serum concentrations of chemerin and cytokines were estimated with ELISA. Results: No statistically significant difference in serum chemerin was found between the studied and the control group. We have documented a significantly higher level of IL-1b, IL-6, TNF-α and IL-10 in CF patients when compared to healthy controls. Neither the chemerin nor the cytokine levels correlated with parameters of nutritional status in our cohort. No statistically significant correlation was found between the serum chemerin and the inflammatory cytokines: IL-1b, IL-6, and TNFα. Conclusions: Our results show that chemerin is not associated with the nutritional status in children with cystic fibrosis. Chemerin has no impact on the levels of IL-1b, IL-6, TNFα in CF patients. IL-1b, IL6, TNFα and also IL10 are upregulated in cystic fibrosis.

Inflammatory bowel disease (IBD) is a chronic condition whose pathogenesis is not entirely clear. Impaired immune regulation has been hypothesized as the mechanism responsible for the abnormal response of adoptive immunity to enteric microbial antigens. Regulatory T cells (Tregs) have been regarded as the crucial element of immune regulation, since the discovery that humans lacking Tregs due to mutation of FOXP3 develop autoimmune disorders, including severe bowel inflammation. The existing publications concerning T regulatory cells in human IBD have been reviewed, and current evidence does not clearly indicate quantitative disturbances or functional defects of Tregs in human inflammatory bowel disease. The possible mechanisms explaining immunoregulatory failure in IBD have been summarized. So far, only one clinical trial with Tregs infusion has been completed, and its results do not provide sufficient data on the efficacy or safety of Tregs-based therapies in IBD. It will probably be difficult to implement them in clinical practice in the near future.

The cholera vaccine can protect patients with inflammatory bowel disease (IBD) against both cholera and travelers’ diarrhea. However, both immunosuppressive treatment and IBD can affect its vaccine immunogenicity. The aim of this study was to assess the immunogenicity and safety of the cholera vaccine in children with IBD. Children older than 6 years with diagnosed IBD were enrolled in this multicenter study. All patients were administered two doses of the oral cholera vaccine (Dukoral®). Anti-cholera toxin B subunit IgA and IgG seroconversion rates were evaluated in a group with immunosuppressive (IS) treatment and a group without IS treatment (NIS). Immunogenicity was assessed in 70 children, 79% of whom received IS treatment. Post-vaccination seroconversion was displayed by 33% of children, for IgA, and 70% of children, for IgG. No statistically significant differences were found in the immune responses between the IS and NIS groups: 35% vs. 27% (p = .90), for IgA, and 68% vs. 80.0% (p = .16), for IgG, respectively. One case of IBD exacerbation after vaccination was reported. The oral cholera vaccine is safe. The immunogenicity of the oral cholera vaccine in children with IBD was lower than previously observed in healthy ones. The treatment type does not seem to affect the vaccine immunogenicity.