Analysis of Circulating Food Antigen-Specific T-Cells in Celiac Disease and Inflammatory Bowel Disease.

To demonstrate and analyze the specific T-cell response following barrier disruption and antigen translocation, circulating food antigen-specific effector T-cells isolated from peripheral blood were analyzed in patients suffering from celiac disease (CeD) as well as inflammatory bowel disease (IBD). We applied the antigen-reactive T-cell enrichment (ARTE) technique allowing for phenotypical and functional flow cytometric analyses of rare nutritional antigen-specific T-cells, including the celiac disease-causing gliadin (gluten). For CeD, patient groups, including treatment-refractory cases, differ significantly from healthy controls. Even symptom-free patients on a gluten-free diet were distinguishable from healthy controls, without being previously challenged with gluten. Moreover, frequency and phenotype of nutritional antigen-specific T-cells of IBD patients directly correlated to the presence of small intestinal inflammation. Specifically, the frequency of antigen specific T-cells as well as pro-inflammatory cytokines was increased in patients with active CeD or Crohn's disease, respectively. These results suggest active small intestinal inflammation as key for the development of a peripheral food antigen-specific T-cell response in Crohn's disease and celiac disease.

Expression and function of α4ß7 integrin predict the success of vedolizumab treatment in inflammatory bowel disease.

Inflammatory bowel diseases are medically intractable and require constant therapy in many cases. While a growing number of biologicals and small molecules is available for treatment, a substantial portion of patients experiences primary non-response to these compounds and head-to-head evidence for therapy selection is scarce. Thus, approaches to predict treatment success in individual patients are a huge unmet need. We had previously suggested that the expression and function of α4ß7 integrin on T cells in the peripheral blood correlate to outcomes of therapy with the anti-α4ß7 integrin antibody vedolizumab. Here, we conducted a translational multicenter trial to prospectively evaluate this hypothesis. In a cohort of 89 patients with inflammatory bowel disease undergoing regular therapy with vedolizumab, lower baseline expression of α4ß7 was associated with short-term clinical response. Consistently, low α4ß7 expression in patients achieving remission predicted sustained remission in week 30. Moreover, high dynamic adhesion of CD4+ T cells to MAdCAM-1 and high reduction of adhesion by vedolizumab in vitro at baseline were associated with clinical remission. These data substantiate the potential of α4ß7 integrin function and expression to forecast outcomes of vedolizumab therapy. Further translational efforts are necessary to improve the performance of the assays and to implement the concept in clinical practice.

TNF hampers intestinal tissue repair in colitis by restricting IL-22 bioavailability.

Successful treatment of chronic inflammatory diseases integrates both the cessation of inflammation and the induction of adequate tissue repair processes. Strikingly, targeting a single proinflammatory cytokine, tumor necrosis factor (TNF), induces both processes in a relevant cohort of inflammatory bowel disease (IBD) patients. However, the molecular mechanisms underlying intestinal repair following TNF blockade during IBD remain elusive. Using a novel humanized model of experimental colitis, we demonstrate that TNF interfered with the tissue repair program via induction of a soluble natural antagonist of IL-22 (IL-22Ra2; IL-22BP) in the colon and abrogated IL-22/STAT3-mediated mucosal repair during colitis. Furthermore, membrane-bound TNF expressed by T cells perpetuated colonic inflammation, while soluble TNF produced by epithelial cells (IECs) induced IL-22BP expression in colonic dendritic cells (DCs) and dampened IL-22-driven restitution of colonic epithelial functions. Finally, TNF induced IL-22BP expression in human monocyte-derived DCs and levels of IL22-BP correlated with TNF in sera of IBD patients. Thus, our data can explain how anti-TNF therapy induces mucosal healing by increasing IL-22 availability and implicates new therapeutic opportunities for IBD.

PuraStat in gastrointestinal bleeding: results of a prospective multicentre observational pilot study.

BACKGROUND: A recently developed haemostatic peptide gel for endoscopic application has been introduced to improve the management of gastrointestinal bleeding. The aim of this pilot study was to evaluate the feasibility, safety, efficacy and indication profiles of PuraStat in a clinical setting. METHODS: In this prospective observational multicentre pilot study, patients with acute non-variceal gastrointestinal bleeding (upper and lower) were included. Primary and secondary application of PuraStat was evaluated. Haemoglobin, prothrombin time, platelets and transfusion behaviour were documented before and after haemostasis. The efficacy of PuraStat was assessed during the procedure, at 3 days and 1 week after application. RESULTS: 111 patients with acute gastrointestinal bleeding were recruited into the study. 70 percent (78/111) of the patients had upper gastrointestinal bleeding and 30% (33/111) had lower gastrointestinal bleeding. After primary application of PuraStat, initial haemostatic success was achieved in 94% of patients (74/79, 95% CI 88-99%), and in 75% of the patients when used as a secondary haemostatic product, following failure of established techniques (24/32, 95% CI 59-91%). The therapeutic success rates (absence of rebleeding) after 3 and 7 days were 91% and 87% after primary use, and 87% and 81% in all study patients. Overall rebleeding rate at 30 day follow-up was 16% (18/111). In the 5 patients who finally required surgery (4.5%), PuraStat allowed temporary haemostasis and stabilisation. CONCLUSIONS: PuraStat expanded the therapeutic toolbox available for an effective treatment of gastrointestinal bleeding sources. It could be safely applied and administered without complications as a primary or secondary therapy. PuraStat may additionally serve as a bridge to surgery in order to achieve temporary haemostasis in case of refractory severe bleeding, possibly playing a role in preventing immediate emergency surgery.

Combination of Vedolizumab With Tacrolimus Is More Efficient Than Vedolizumab Alone in the Treatment of Experimental Colitis.

BACKGROUND: Vedolizumab is a widely used and safe therapy in inflammatory bowel disease, particularly in ulcerative colitis (UC), making it a promising candidate for enhanced efficacy by combining it with additional immunomodulatory medications. In this study, we studied the impact of vedolizumab monotreatment vs vedolizumab coadministration with other immunomodulatory drugs on intestinal inflammation and intestinal immune cells in vivo. METHODS: Colon tissue from human patients with UC with active disease or in remission with or without vedolizumab treatment was stained by immunohistochemistry. We reconstituted NOD-SCID-SGM3 mice with human CD34+ cells and treated them with dextran sodium sulfate to induce acute colitis. Mice were treated with vedolizumab alone, or in combination with tacrolimus, ozanimid, or tofacitinib. RESULTS: Vedolizumab reduced the number of CD3+ T cells and CD68+ monocytes/macrophages in the colon of patients with UC with active disease. Vedolizumab moderately decreased immune cell numbers in acute dextran sodium sulfate-induced colitis. The combination of vedolizumab with tacrolimus further reduced the number of infiltrating CD3+ T cells and CD68+ monocytes/macrophages and was superior in ameliorating intestinal inflammation when compared to vedolizumab monotreatment. In contrast, cotreatment using vedolizumab with ozanimod or tofacitinib had no additive effect. CONCLUSIONS: Our data show that vedolizumab reduces the number of innate and adaptive immune cells in the mucosa of patients with UC. Further, the combination of vedolizumab with tacrolimus was more efficient to reduce immune cell numbers and to increase therapeutic efficacy than vedolizumab monotreatment. This finding indicates that combination treatment using these two drugs may be beneficial for patients who do not respond to vedolizumab monotherapy.

Level of Tumor Necrosis Factor Production by Stimulated Blood Mononuclear Cells Can Be Used to Predict Response of Patients With Inflammatory Bowel Diseases to Infliximab.

BACKGROUND & AIMS: A substantial proportion patients with inflammatory bowel disease (IBD) have a primary non-response to infliximab; markers are needed to identify patients most likely to respond to treatment. We investigated whether production of tumor necrosis factor (TNF) by peripheral blood mononuclear cells (PBMCs) can be used as a marker to predict response. METHODS: We performed a prospective study of 41 adults with IBD (mean age, 38 years; 21 male; 21 with Crohn's disease and 20 with ulcerative colitis) not treated with a biologic agent within the past 6 months; patients were given their first infusion of infliximab at a hospital or clinic in Berlin, Germany. We collected data on clinical scores, levels of C-reactive protein, and ultrasound results (Limberg scores) at baseline (before the first infusion) and after 6 weeks (3rd infliximab infusion). PMBCs were obtained from patients at baseline and 10 healthy individuals (controls) and incubated with lipopolysaccharide. We measured production of cytokines (TNF, interleukin 1 [IL1], IL6, IL8, IL10, IL12p70, and IL22) by ELISA and performed cytometric bead array and flow cytometry analyses. The primary endpoint was clinical response (decrease in Harvey Bradshaw Index scores of 2 or more or decrease in partial Mayo scores of 3 or more at week 6) in patients with PBMCs that produced high vs low levels of TNF. RESULTS: Responders had a shorter median disease duration (P = .018) and higher median Limberg score (P = .021), than nonresponders. Baseline PBMCs from responders produced significantly more TNF (P = .049) and IL6 (P = .028) than from nonresponders; a level of 500 pg/ml TNF identified responders with 82% sensitivity and 78% specificity. In patients with Crohn's disease, this cutoff value (500 pg/ml TNF) identified responders with 100% sensitivity and 82% specificity; TNF levels above this level were independently associated with response to infliximab in multivariate analysis (odds ratio, 16.2; 95% CI, 1.8-148.7; P = .014). The percentage of TNF-positive cells was higher among CD14+ monocytes than lymphocytes after stimulation. CONCLUSIONS: Production of a high level of TNF by PBMCs (specifically CD14+ cells) from patients with IBD can identify those most likely to have a clinical response to infliximab therapy. In patients with Crohn's disease, a cutoff value of 500 pg/ml TNF identified responders with 100% sensitivity and 82% specificity.

Passive Smoking Increases the Risk for Intestinal Surgeries in Patients With Crohn's Disease.

BACKGROUND: Despite substantial evidence on the negative effect of active smoking, the impact of passive smoking on the course of Crohn's disease (CD) remains largely unclear. Our aim was to assess passive smoking as a risk factor for intestinal surgeries in CD. METHODS: The study was conducted in a university-based, monocentric cohort of 563 patients with CD. Patients underwent a structured interview on exposure to passive and active smoking. For clinical data, chart review was performed. Response rate was 84%, leaving 471 cases available for analysis. For evaluation of the primary objective, which was the impact of exposure to passive smoking on the risk for intestinal surgery, only never actively smoking patients were included. RESULTS: Of 169 patients who never smoked actively, 91 patients (54%) were exposed to passive smoking. Exposed patients were more likely to undergo intestinal surgery than nonexposed patients (67% vs 30%; P < 0.001). Multivariate Cox regression analysis revealed that passive smoking was an independent risk factor for intestinal surgeries (hazard ratio, 1.7; 95% CI, 1.04-2.9; P = 0.034) after adjustment for ileal disease at diagnosis (hazard ratio, 2.9; 95% CI, 1.9-4.5; P < 0.001) and stricturing or penetrating behavior at diagnosis (hazard ratio, 1.9; 95% CI, 1.2-3.1; P = 0.01). Passive smoking during childhood was a risk factor for becoming an active smoker in later life (odds ratio, 2.2; 95% CI, 1.5-3.2; P < 0.001). CONCLUSION: Passive smoking increases the risk for intestinal surgeries in patients with CD.

[Cancer Surveillance in Inflammatory Bowel Diseases]. / Tumor-Surveillance bei chronisch entzündlichen Darmerkrankungen.

Patients with ulcerative colitis and Crohn's colitis, especially in the presence of primary sclerosing cholangitis, have an increased risk of developing colorectal cancer due to the longstanding colonic inflammation. Therefore, anti-inflammatory drugs reduce this elevated risk.On the other hand, immunosuppressive medication can have direct mutagen effects or can lead to compromised tumor surveillance, therefore increasing the risk of extra-intestinal tumors. This article reviews recommendations concerning cancer surveillance strategies in patients with inflammatory bowel diseases.

[Inflammatory bowel disease: cardinal signs and their diagnostics]. / Chronisch entzündliche Darmerkrankungen: Leitsymptome und Diagnostik.

Inflammatory bowel diseases, including Crohn's disease and ulcerative colitis, often occur early in life. Therefore, they affect our patient's individual path of life, their ability to work and the quality of life tremendously, which calls for close and comprehensive medical care. This article features 5 cardinal signs and their diagnostics.

Are Immunosuppressants Becoming Obsolete?

Historically, in the 1950s, the introduction of simple, old-fashioned steroids resulted in a significant drop in mortality and hence offered for the first time a real therapeutic option for patients with inflammatory bowel disease. However, as we are all aware of, steroids are no option for maintenance of remission. This review will provide an overview of the available data on the current role of azathioprine in the therapy of Crohn's disease. Based on several controlled trials, the place of azathioprine for maintenance of remission is indisputable. Data from a pediatric cohort suggested that early introduction of azathioprine is beneficial for the disease course. Two recent studies aimed at reproducing these data in adult populations and failed. Hence indicating that azathioprine should only be introduced for maintenance of remission in a step-up-wise approach. An additional role for azathioprine in combo therapy with TNF antibodies has been indicated by several trials revealing a substantial benefit on response. This is partly attributed to the gain in the therapeutic effect by azathioprine itself and possibly through reduction of anti-drug antibody development. In summary, the current role of azathioprine in the therapy of Crohn's disease is manifold and still has an impact in times of targeted therapy.

Monocyte and M1 Macrophage-induced Barrier Defect Contributes to Chronic Intestinal Inflammation in IBD.

BACKGROUND: Macrophages are key players in inflammatory bowel diseases (IBD). This study aimed to determine site-specific effects of defined macrophage subtypes on the integrity of the intestinal epithelial barrier. METHODS: Macrophage subtypes in situ in intestinal specimens of patients with IBD were visualized by immunohistochemistry. In vitro polarization of human peripheral CD14 cells yielded M1 or M2 macrophages. The influence of primary monocytes or macrophage subtypes on epithelial barrier integrity was analyzed by transepithelial resistance measurements, Western blot analysis, confocal laser scanning microscopy, and cytometric bead array in a coculture model of primary human macrophages and layers of intestinal epithelial cell lines. RESULTS: The lamina propria of the inflamed intestine in patients with IBD, predominantly in Crohn's disease, is massively infiltrated by CD68 cells also positive for inducible nitric oxide synthase and tumor necrosis factor (TNF) α. The presence of M1 macrophage shifted the balance in the local macrophage compartment towards a proinflammatory state. In the coculture model, monocytes and M1 macrophages reduced transepithelial resistance as a marker for epithelial barrier integrity. The mechanisms for paracellular leakage included intracellular relocalization of tight junction proteins like claudin-2 and epithelial cell apoptosis. Determined by specific cytokine blockade, M1 macrophages exerted their deleterious effect mainly through TNF-α, whereas monocyte-mediated damage was driven by the inflammasome effector cytokines, interleukin-1ß and interleukin-18. CONCLUSIONS: Lamina propria monocytes and M1 macrophages invading intestinal tissues directly contribute to disrupting the epithelial barrier through deregulation of tight junction proteins and induction of epithelial cell apoptosis, thus driving intestinal inflammation in IBD.

Ulcerative colitis: current and future treatment strategies.

Since the incidence of inflammatory bowel diseases including ulcerative colitis is continuously increasing worldwide, there is a strong need for effective treatment strategies. However, there is no therapy allowing for healing ulcerative colitis; consequently, the available medications will have to be applied at their best. The preferred option for mild pan- or left-sided colitis is still mesalazine. One can only emphasize that the formulations allowing for once daily dosing are not only equally effective, but even facilitate the implication of long-term therapy in daily life. In case steroids are frequently required to control disease, further immunosuppressive therapy should be introduced in order to minimize steroid exposure. Thiopurines represent the first-choice immunosuppressive medication. In more severe cases, early escalation to combinatory therapies with anti-TNF antibodies should be considered with the possibility of therapy deescalation after induction of remission. Major difficulties arise with steroid-refractory acute flares. Here cyclosporine as well as anti-TNF strategies can be initiated. However, in case of severe disease, the high 1-year colectomy rate of about 50% should be considered. If short-term surgery is an option due to disease severity, cyclosporine might be advantageous since the half-life is short compared to infliximab or adalimumab. The central problem of all therapeutic approaches is that because we chase after the disease, solid markers that allow for prediction of the future disease course are desirable. In fact, the CD8+ transcriptome might fill this gap and will potentially lead to the classification of patients in low- and high-risk groups.

The multifaceted role of the inflammasome in inflammatory bowel diseases.

Inflammasomes are intracellular multiprotein complexes that coordinate the maturation of interleukin (IL)-1 beta and IL-18 in response to pathogens and metabolic danger. Both cytokines have been linked to intestinal inflammation. However, recently evolving concepts ascribe a major role to the inflammasome in maintaining intestinal homeostasis. This review recapitulates its position in the development of inflammatory bowel disease, thereby outlining a model in which hypo- as well as hyperfunctionality can lead to an imbalance of the system, depending on the specific cell population affected. In the epithelium, the inflammasome is essential for regulation of permeability and epithelial regeneration through sensing of commensal microbes, while excessive inflammasome activation within the lamina propria contributes to severe intestinal inflammation.

The impact of thiopurines on the risk of surgical recurrence in patients with Crohn's disease after first intestinal surgery.

OBJECTIVES: Smoking and a lack of immunosuppressive (IS) therapy are considered risk factors for intestinal surgery in Crohn's disease (CD). Good evidence for the latter is lacking. The objective of this study was to evaluate the impact of thiopurine treatment on surgical recurrence in patients after first intestinal resection for CD and its possible interaction with smoking. METHODS: Data on 326 patients after first intestinal resection were retrieved retrospectively, and subjects were grouped according to their postoperative exposure to thiopurines. Treatment with either azathioprine (AZA) or 6-mercaptopurine (6-MP) was recorded on 161 patients (49%). Smoking status was assessed by directly contacting the patients. RESULTS: Surgical recurrence occurred in 151/326 (46.3%) patients after a median time of 71 (range 3-265) months. Cox regression revealed a significant reduction of re-operation rate in patients treated with AZA/6-MP for > or = 36 months as compared with patients treated for 3-35 months, for less than 3 months, and to those without postoperative treatment with AZA/6-MP (P=0.004). Cox regression analysis revealed treatment with thiopurines for > or = 36 months (hazard ratio (HR) 0.41; 95% confidence interval (CI) 0.23-0.76, P=0.004) and smoking (HR 1.6; 95% CI 1.14-2.4, P=0.008) as independent predictors for surgical recurrence. Furthermore, longer duration of disease tended to be protective (HR 0.99; 95% CI 0.99-1.0, P=0.067). CONCLUSIONS: Long-term maintenance treatment with AZA/6-MP reduces the risk of surgical recurrence in patients with CD. We also identified smoking as a risk factor for surgical recurrence.