Miriam Fort Gasia

Increased prevalence of circulating novel IL-17 secreting Foxp3 expressing CD4+ T cells and defective suppressive function of circulating Foxp3+ regulatory cells support plasticity between Th17 and regulatory T cells in inflammatory bowel disease patients.

Background:IL-17 and Foxp3 double-expressing (DE) CD4+ T lymphocytes are novel crossover immune cell population, but the presence and role of these cells in human intestinal inflammation is unclear. The aim of this study was to investigate the circulating IL-17 and Foxp3 DE CD4+ T lymphocytes in patients with inflammatory bowel disease (IBD). Methods:The entire cohort consisted of 79 subjects: 31 patients with Crohns disease, 28 patients with ulcerative colitis, and 20 healthy control subjects (HC). IBD patients with evidence of active disease at endoscopy were entered into the study. Peripheral blood mononuclear cells were used for ex vivo and in vitro studies to assess the characteristics and generation of these novel cells and the function of circulating Foxp3+ CD4+ regulatory T lymphocytes (Treg) in patients with IBD compared with HC. Results:Patients with IBD had significantly higher prevalence of IL-17 and Foxp3 DE CD4+ T lymphocytes compared with age- and gender-matched HC. These cells expressed ROR&ggr;t. The ability of Treg cells to suppress autologous T-cell proliferation was reduced by approximately 60% in patients with IBD compared with HC. Increased generation of these DE cells was demonstrated by the modulation of cytokine environment of CD4+ lymphocytes in vitro in patients with Crohns disease. Conclusions:Prevalence of circulating IL-17 and Foxp3 DE CD4+ T cells is increased in patients with IBD. Coexpression of ROR&ggr;t and Foxp3 in these cells implies conversion from Treg cells to Th17 cells. This is associated with a decreased suppressive function of Foxp3+ CD4+ T lymphocytes in patients with IBD.

Complete mucosal healing defined by endoscopic Mayo subscore still demonstrates abnormalities by novel high definition colonoscopy and refined histological gradings.

BACKGROUND AND STUDY AIMS A novel high definition colonoscopy imaging technique (i-Scan) can characterize, in detail, colonic mucosa in patients with ulcerative colitis, and may provide additional information about mucosal healing. The aim of this study was to create a more refined histological and endoscopic criteria based on this novel technique in order to redefine inflammatory activity and mucosal healing. PATIENTS AND METHODS A total of 78 patients with ulcerative colitis were assessed by high definition colonoscopy as well as by white light endoscopy (WLE). Mayo endoscopic subscores were assigned to patients according to WLE findings. Mucosal and vascular patterns on high definition colonoscopy were each graded from 1 - 4. A histological scoring system (ECAP system) was designed to reflect all histological changes in ulcerative colitis. RESULTS The overall high definition imaging scores (mucosal and vascular patterns) were significantly correlated with Mayo endoscopic subscores (rs = 0.86, 95 % confidence interval [CI] 0.79 - 0.91; P < 0.0001). Of those with Mayo endoscopic subscore of 0, 30.4 % had an abnormal mucosal pattern and 73.9 % of them had an abnormal vascular pattern on high definition colonoscopy; a score of 6 or less had a sensitivity of 95.8 % (95 %CI 85.7 % - 99.3 %) and specificity of 75.9 % (95 %CI 56.5 % - 90.0 %) to detect mucosal healing as defined by Mayo endoscopy subscore of 0 or 1. Furthermore, mucosal and vascular pattern scores were also significantly correlated with most parameters of the proposed ECAP score. CONCLUSION The subtle histological abnormalities underlying the apparently healed mucosa in ulcerative colitis could be detected using high definition colonoscopy and the refined ECAP histology scoring system. These techniques detect residual abnormalities in the majority of patients with seemingly complete mucosal healing by conventional Mayo criteria.

Targeted Biopsies Identify Larger Proportions of Patients With Colonic Neoplasia Undergoing High-Definition Colonoscopy, Dye Chromoendoscopy, or Electronic Virtual Chromoendoscopy.

BACKGROUND & AIMS It is unclear what are the best and most appropriate endoscopic procedures for detecting colonic neoplasia in patients with long-term colonic inflammatory bowel disease (IBD). Dye chromoendoscopy (DCE) is the standard used in IBD surveillance colonoscopies. However, studies are needed to determine the optimal endoscopic technique for detecting dysplastic lesions. We investigated current practices used in surveillance colonoscopies by IBD gastroenterologists at a single tertiary center. We also determined the rate of neoplasia detection among different surveillance endoscopic techniques in an analysis of random or targeted biopsies. METHODS We collected data on 454 patients with IBD (54.5% male; mean age, 50 y; mean disease duration, 14.5 y; 55.9% with ulcerative colitis, 42.7% with Crohns disease, and 1.3% with indeterminate colitis) who underwent surveillance colonoscopy from April 2011 through March 2014 at the University of Calgary in Canada. Subjects were examined using white-light standard-definition endoscopy (WLE), high-definition (HD) colonoscopy, virtual electronic chromoendoscopy (VCE), or DCE; random or targeted biopsy specimens were collected. Endoscopic and histologic descriptions with suspected neoplasia were recorded. Rates of neoplasia detection by the different endoscopic procedures were compared using chi-square analysis. RESULTS Of the patients analyzed, 27.7% had WLE endoscopy with random collection of biopsy specimens, 27.3% had HD colonoscopy with random collection of biopsy specimens, 14.1% had VCE with random collection of biopsy specimens, 0.9% had DCE with random collection of biopsy specimens, 12.8% had HD colonoscopy with collection of targeted biopsy specimens, 11.9% had VCE with collection of targeted biopsy specimens, and 5.3% had DCE with collection of targeted biopsy specimens. Neoplastic lesions were detected in 8.2% of the procedures performed in the random biopsy group (95% confidence interval, 5.6-11.7) and 19.1% of procedures in the targeted biopsy group (95% confidence interval, 13.4-26.5) (P < .001). Neoplasias were detected in similar proportions of patients by HD colonoscopy, VCE, or DCE, with targeted biopsy collection. CONCLUSIONS In a large cohort of IBD patients undergoing surveillance colonoscopy, targeted biopsies identified greater proportions of subjects with neoplasia than random biopsies. Targeted collection of biopsy specimens appears to be sufficient for detecting colonic neoplasia in patients undergoing HD colonoscopy, DCE, or VCE, but not WLE.

Opposing Effects of Smoking in Ulcerative Colitis and Crohn's Disease May Be Explained by Differential Effects on Dendritic Cells

Background:The mechanisms underlying the differential effects of cigarette smoking in patients with Crohns disease (CD) and ulcerative colitis (UC) remain unknown. Smoking has been demonstrated to be protective in UC, whereas in CD it has been shown to be associated with a more severe course, more frequent relapses, and postoperative recurrence. Dendritic cells (DC) play a critical role in T-cell activation and differentiation. Thus, we examined the effects of in vitro exposure to cigarette smoke extract (CSE) on phenotype/function of DC obtained from patients with UC and CD. Methods:Sixty-eight subjects were recruited including 30 patients with CD, 19 patients with UC, and 19 healthy controls. Peripheral blood monocytes were differentiated to DC in presence of IL-4 and granulocyte-macrophage colony-stimulating factor. The influence of CSE on Mo-DC subsets, cytokine expression, and ability to drive T cell proliferation and polarization were examined. Results:CSE affected DC phenotypes including increases in class-2 major histocompatibility complex and costimulatory molecules and decreases in CXCL10 and CCL3 levels in UC compared with CD samples. Furthermore, CSE also altered DC function resulting in increasing T cell proliferation and Th1 polarization in CD, whereas it increased Foxp3+ T cells and decreased the Th1 subset in UC samples. Conclusions:CSE modulates DC phenotype and function in patients with UC leading to increased prevalence of Foxp3+ CD4+ T cells, whereas in patients with CD it skews toward Th1 subsets. Differential DC responses to CSE between CD and UC may contribute to the differential effects associated with cigarette smoking status.

Profiles of Lamina Propria T Helper Cell Subsets Discriminate Between Ulcerative Colitis and Crohn's Disease.

Background:Distinction between 2 forms of inflammatory bowel disease (IBD), ulcerative colitis (UC) and Crohns disease (CD), can be challenging. Aberrant mucosal immunity suggests that CD is a T helper type 1 cell (Th1)-driven disease, whereas UC as Th2-driven response. However, whether this paradigm truly distinguishes CD from UC is controversial. We aimed to clarify the discriminating potential of lamina propria Th subsets in patients with IBD. Methods:Biopsies from 79 patients with IBD and 20 healthy controls were collected for Th subsets analysis (Th1:interferon &ggr; [IFN-&ggr;], T-bet; Th2:interleukin 13 [IL-13], Gata3; Th17:IL-17, ROR&ggr;t; Treg:FoxP3). The receiver-operating characteristic curves were constructed to assess the discriminating ability by calculating the area under the receiver-operating characteristic curve. The equation with the highest area under the receiver-operating characteristic curve was applied to newly diagnosed patients to evaluate discriminating ability. Results:Patients with CD showed increased IFN-&ggr;+ or T-bet+ cells and decreased IL-13+ or Gata3+ cells compared with UC. A discriminant equation composed of 4 markers (IFN-&ggr;+, T-bet+, IL-13+, and Gata3+) yielded the highest area under the receiver-operating characteristic curve. In 36 established CD or UC, the sensitivity, specificity, positive and negative predictive probabilities were 92.6%, 55.6%, 86.2%, and 71.4% and in 14 newly diagnosed patients were 100.0%, 42.9%, 63.6%, and 100.0%. Furthermore, Gata3+ cells were increased in tumor necrosis factor inhibitor therapy nonresponders compared with responders in CD. IFN-&ggr;+ cells were directly and inversely proportional to disease activity in patients with CD and UC, respectively. Conclusions:The Th1/Th2 paradigm can distinguish CD from UC and may be further associated with response to tumor necrosis factor inhibitor in CD and disease activity in patients with IBD.

Immunogenicity of Influenza Vaccine for Patients with Inflammatory Bowel Disease on Maintenance Infliximab Therapy: A Randomized Trial.

Background:In patients with inflammatory bowel disease (IBD) on infliximab, data are limited on immune response to influenza vaccine and the impact of vaccine timing. The study aims were to evaluate immune responses to the influenza vaccine in IBD patients on infliximab and the impact of vaccine timing on immune responses. Methods:In this randomized study, 137 subjects with IBD on maintenance infliximab therapy were allocated to receive the 2012/2013 inactivated influenza vaccine at the time of infliximab infusion (n = 69) or midway between infusions (n = 68). Serum was collected before and after vaccination for hemagglutination inhibition titers. Serologic protection was defined by postvaccine titer of ≥1:40. Results:Comparing subjects vaccinated at the time of infliximab with those vaccinated midway, serologic protection was achieved in 67% versus 66% to H1N1 (P = 0.8), in 43% versus 49% to H3N2 (P = 0.5), and in 69% versus 79% to influenza B (P = 0.2). Although solicited adverse events were common (60%), no subject experienced a serious adverse event requiring additional medical attention. Only 6% of subjects had a clinically significant increase in disease activity score, not impacted by vaccine timing. Conclusions:Serologic protection to influenza vaccine is achieved in only approximately 45% to 80% of IBD patients on maintenance infliximab therapy varying by antigen. Yet, importantly, vaccine timing relative to infliximab infusion does not affect the achievement of serologic protection, and the influenza vaccine is well tolerated. Therefore, influenza vaccination at any point during infliximab scheduling is recommended for patients with IBD and opportunities to broaden the availability and convenience of influenza vaccine to optimize coverage should be explored.

Serrated Adenoma Prevalence in Inflammatory Bowel Disease Surveillance Colonoscopy, And Characteristics Revealed by Chromoendoscopy and Virtual Chromoendoscopy

BACKGROUND Sessile or nonpolypoid neoplastic lesions, including sessile serrated adenomas (SSAs), are difficult to detect in patients with inflammatory bowel disease (IBD). OBJECTIVES To assess the prevalence and endoscopic features of SSA in IBD patients undergoing surveillance colonoscopy using novel endoscopic techniques. METHODS Histology results of biopsies from a cohort of 87 patients (47 men; median age 51.4 years; median duration of disease 16.9 years; ulcerative colitis [n=40], Crohn disease [n=43], ischemic colitis [n=4]) with longstanding colonic IBD undergoing surveillance colonoscopy were reviewed. Lesions of dysplasia (adenoma-like mass, or dysplasia-associated lesion or mass), SSAs, adenoma-like polyps, hyperplastic polyps and inflammatory polyps were identified. Surveillance colonoscopy using high-definition alone, or with iScan (Pentax, USA) dye-sprayed or virtual chromoendoscopy was performed. Lesion characteristics were described before histological diagnosis. RESULTS Fourteen SSAs were detected in 87 (11%) IBD patients. The endoscopic characteristics of SSA lesions were: nonpolypoid appearance (86%), predominant localization in the proximal colon (79%), >6 mm in size (79%), cloudy cover (64%), Kudo pit pattern modified type IIO (86%) and irregular spiral vascular pattern (79%). Among the 44 SSAs and hyperplastic polyps found in the present study, the above characteristics of SSA at colonoscopy had a sensitivity of 92.86% (95% CI 66.06% to 98.8%) and specificity of 93.33% (95% CI 77.89% to 98.99%) in predicting a histological diagnosis of SSA (positive predictive value 86.67%, negative predictive value 96.55%). CONCLUSION SSAs are a common finding at surveillance colonoscopy in IBD and have several characteristic features. Further studies are needed to evaluate the natural history of these lesions in IBD patients.

Novel CD8+ T-Cell Subsets Demonstrating Plasticity in Patients with Inflammatory Bowel Disease.

Background:Distinct CD8+ T-cell subsets such as interleukin-17-expressing Tc17 and Foxp3-expressing Tcreg are functionally similar to CD4+ T cells. Though CD4+ T cells are dysregulated in patients with inflammatory bowel disease (IBD), CD8+ T cells are not well investigated. Vitamin D is an environmental factor which influences T-cell subsets. We assessed the prevalence of CD8+ T-cell subsets among peripheral blood mononuclear cells (PBMC) and lamina propria mononuclear cells (LPMC) of patients with Crohns disease, patients with ulcerative colitis, and healthy controls. We then tested the effect of 1&agr;,25-dihydroxyvitamin D3 on CD8+ T-cell subsets. Methods:A total of 73 patients with Crohns disease, 49 patients with ulcerative colitis, and 47 healthy controls were studied. LPMC or PBMC were isolated and flow cytometry was performed. CD3+ T cells, isolated from PBMC, were cultured with or without 1&agr;,25-dihydroxyvitamin D3, before flow cytometry. Results:In LPMC, the prevalence of Tcreg was higher in patients with IBD (P < 0.05), whereas Tc17 were higher in patients with ulcerative colitis compared with patients with Crohns disease and healthy controls (P < 0.05). In PBMC, both Tcreg and Tc17 were higher in patients with IBD (P < 0.01). Double-expressing interferon-&ggr;+ interleukin-17+ and Foxp3+ interleukin-17+ CD8+ T cells were also identified indicating possible CD8+ plasticity. 1&agr;,25-dihydroxyvitamin D3 decreased interferon-&ggr;–expressing Tc1 (P < 0.05), but had no effect on Tc17 or Tcreg. Conclusions:The prevalence of novel CD8+ T-cell subsets is altered in patients with IBD. Double-expressing cells indicate plasticity and were identified in patients with IBD. Vitamin D may have a limited effect on CD8+ T cells by decreasing interferon-&ggr; expression.

Endoscopic Submucosal Dissection in the Colorectum: Feasibility in the Canadian Setting

Endoscopic submucosal dissection is a minimally invasive endoscopic technique for the removal of gastrointestinal tumours that is increasingly being used for colonic neoplasms to spare resection of colon in selected patients. Colonic endoscopic submucosal dissection is technically challenging and was initially pioneered in Japan but increasingly used in selected western centres. Its use in Canada is currently limited, and the authors review the challenges and opportunities, in addition to the unique training infrastructure required to practice the procedure under supervision. Specific tools are required to perform endoscopic submucosal dissection and meticulous attention to detail is essential. The authors provide a combined Japanese and Canadian perspective to this technique, and discuss training and performance of endoscopic submucosal dissection as well as potential indications.

Sa1754 Distinctive Th17 Lymphocyte Plasticity in Intestinal Lamina Propria of IBD Patients Compared With Healthy Controls

Interleukin-6 Drives Production of Pathogenic Cytokines by Innate Lymphoid Cells in Patients and Mice With Chronic Intestinal Inflammation Nick Powell, Jonathan W. Lo, Paolo Biancheri, Anna Vossenkamper, Eirini D. Pantazi, Emilie Stolarczyk, Alan Walker, Paul Scott, James B. Canavan, Esperanza Perucha, Natividad Garrido-Mesa, Ian Jackson, Francesca Ammoscato, Peter M. Irving, Jeremy D. Sanderson, Bu Hayee, Julian Parkhill, MacDonald Thomas, Graham M. Lord