IL-13 mRNA Tissue Content Identifies Two Subsets of Adult Ulcerative Colitis Patients With Different Clinical and Mucosa-Associated Microbiota Profiles.

BACKGROUND AND AIMS: A personalized approach to therapy hold great promise to improve disease outcomes. To this end, the identification of different subsets of patients according to the prevalent pathogenic process might guide the choice of therapeutic strategy. We hypothesize that ulcerative colitis [UC] patients might be stratified according to distinctive cytokine profiles and/or to a specific mucosa-associated microbiota. METHODS: In a cohort of clinically and endoscopic active UC patients and controls, we used quantitative PCR to analyse the mucosal cytokine mRNA content and 16S rRNA gene sequencing to assess the mucosa-associated microbiota composition. RESULTS: We demonstrate, by means of data-driven approach, the existence of a specific UC patient subgroup characterized by elevated IL-13 mRNA tissue content separate from patients with low IL-13 mRNA tissue content. The two subsets differ in clinical-pathological characteristics. High IL-13 mRNA patients are younger at diagnosis and have a higher prevalence of extensive colitis than low IL-13 mRNA patients. They also show more frequent use of steroid/immunosuppressant/anti-tumour necrosis factor α therapy during 1 year of follow-up. The two subgroups show differential enrichment of mucosa-associated microbiota genera with a prevalence of Prevotella in patients with high IL-13 mRNA tissue content and Sutterella and Acidaminococcus in patients with low IL-13 mRNA tissue content. CONCLUSION: Assessment of mucosal IL-13 mRNA might help in the identification of a patient subgroup that might benefit from a therapeutic approach modulating IL-13. PODCAST: This article has an associated podcast which can be accessed at https://academic.oup.com/ecco-jcc/pages/podcast.

CD3+CD4+LAP+Foxp3-Regulatory Cells of the Colonic Lamina Propria Limit Disease Extension in Ulcerative Colitis.

Background and Aims: In ulcerative colitis (UC), inflammation begins in the rectum and can extend proximally throughout the entire colon. The extension of inflammation is an important determinant of disease course, and may be limited by the action of regulatory T cells (Tregs). In this cross-sectional study, we evaluated the relationship between UC extension and the proportions of CD3+CD4+Foxp3+ and CD3+CD4+LAP+Foxp3-Tregs in the colonic lamina propria (LP) of 79 UC patients and 29 controls. The role of these cells in UC extension was also investigated in the murine oxazolone-induced colitis model. Methods: Patients: Disease extension was classified according to the Montreal classification. Where possible, endoscopic biopsies of involved and uninvolved tissue were obtained from UC patients. Mouse model: Colitis was induced by intrarectal oxazolone administration. Lamina propria mononuclear cells were isolated from patient biopsies and mouse colon tissue using enzymatic method and the percentage of CD3+CD4+Foxp3+ and CD3+CD4+LAP+Foxp3-cells evaluated by immunofluorescence. Confocal microscopy was applied for the visualization and quantification of CD4+LAP+ cells on tissue histological sections. Results: In UC patients with distal colitis the proportion of LP CD3+CD4+Foxp3+ Tregs was significantly higher in inflamed tissue than uninvolved tissue. As opposite, the proportion of LP CD3+CD4+LAP+ Tregs was significantly higher in uninvolved tissue than involved tissue. Both LP CD3+CD4+Foxp3+ and LP CD3+CD4+LAP+ Tregs proportion in involved tissue was significantly higher than in controls irrespective of the extension of inflammation. In mice with oxazolone-induced distal colitis, treatment with LAP-depleting antibody was associated with the development of extensive colitis. Conclusions: Our findings suggest that CD3+CD4+LAP+Foxp3-Tregs limit the extension of inflammatory lesions in UC patients.

Prevalence of Colonic Diverticulosis in Patients Affected by Ulcerative Colitis: A Prospective Study.

BACKGROUND: Diverticulosis of the colon is an acquired condition that results from herniation of the mucosa and submucosa through defects in the muscular layer. The true prevalence of colonic diverticulosis is difficult to measure because most individuals are asymptomatic. In particularly, in literature, there are few studies about the prevalence of colonic diverticulosis in patients affected by ulcerative colitis (UC). GOALS: To investigate the prevalence of colonic diverticulosis in UC and in adult patients referred in a single center. STUDY: Consecutive patients, referred to our institution to undergo a colonoscopy for colorectal cancer screening and/or for UC assessment, between January 1, 2014 and December 31, 2014, were studied. RESULTS: Six hundred five consecutive patients were studied: 438 (72.4%) due to colorectal cancer screening (group A) and 167 (27.6%) for UC assessment (group B). Prevalence of colonic diverticulosis was higher in group A than group B (27.8% vs. 10.8%, P<0.0001). Female gender in patients with colonic diverticulosis was higher in group A than group B (55.7% vs. 22.2%, P=0.0106). Sigma and left colon was mainly involved in group A than group B (97.6% vs. 66.7%, P=0.0001), whereas in group B the right colon was mainly involved in group B versus group A (22.2% vs. 0.8%, P=0.0009). CONCLUSIONS: Prevalence of colonic diverticulosis was significantly lower in patients with UC than in control group. UC may, therefore, be a protective factor for colonic diverticulosis occurrence.

A randomized trial comparing 4.8 vs. 2.4 g/day of oral mesalazine for maintenance of remission in ulcerative colitis.

BACKGROUND: Mesalazine is used as maintenance therapy in ulcerative colitis but the optimal dosage is still controversial. AIM: To compare the remission-maintenance efficacy and tolerability of two daily doses of oral mesalazine (4.8 g and 2.4 g) in patients with ulcerative colitis with frequent relapses in a randomized controlled trial. METHODS: 112 ulcerative colitis patients in remission were enrolled and randomly allocated to treatment for 1 year with oral mesalazine at a daily dose of 4.8 g (n=56, Group A) or 2.4 g (n=56, Group B). RESULTS: At the end of the 12 months, intention to treat analysis revealed persistent remission in 42 (75%) in Group A and 36 (64.2%) in Group B (p=0.3). The higher daily dose (4.8 g) proved to be significantly more effective for maintaining remission in patients under 40 years of age (90.5% Group A vs. 50% Group B; Fisher's exact test, p=0.0095) and in those with extensive disease (90.9% Group A vs. 46.7% Group B; Fisher's exact test, p=0.0064). CONCLUSIONS: In ulcerative colitis patients younger than 40 years and/or with extensive disease, a daily dose of 4.8 g oral mesalazine results in increased rates and duration of remission compared to 2.4 g.

Extraintestinal manifestations in a large series of Italian inflammatory bowel disease patients.

AIM: To investigate prevalence, type and time of onset of extraintestinal manifestations (EIMs) in a series of Italian inflammatory bowel disease (IBD) patients. METHODS: Data of 811 IBD consecutive patients, first referred to our Centre from 2000 to 2011, were retrospectively evaluated. RESULTS: Eight hundred and eleven IBD patients (437 M, 374 F) were studied: 595 ulcerative colitis (UC) (73.4%) and 216 Crohn's disease (CD) (26.6%). Among these, 329 (40.6%) showed EIMs: 210 UC (35.3%) and 119 CD (55.1%) (P < 0.0001). Considering the time of the diagnosis of IBD, 37 EIMs (11.2%) were developed before, 229 (69.6%) after and 63 (19.2%) were simultaneous. The type of EIM were as follows: 240 musculoskeletal (29.6%), in 72 CD patients and in 168 UC (P < 0.0001); 47 mucocutaneous (5.8%), in 26 CD and in 21 UC (P = 0.0049); 26 ocular (3.2%), in 16 CD and in 10 UC (CD 7.4% vs UC 1.7%, P = 0.0093); 6 hepatobiliary (0.8%); 10 endocrinological (1.2%). In particular, with regards to the involvement of the musculoskeletal system, arthritis Type 1 was found in 41 CD (19%) and in 61 UC (10.2%) (P = 0.0012) and Type 2 in 25 CD (11.6%) and in 100 UC (16.8%) (P = 0.0012). CONCLUSION: Mucocutaneous manifestations, arthritis Type 1 and uveitis were significantly more frequent in CD than UC. The complications of the musculoskeletal system were the mostly observed ones, often with symptoms more severe than intestinal ones, confirming the need for close cooperation with rheumatologists.

Defective expression of scavenger receptors in celiac disease mucosa.

Celiac disease (CD) is a gluten sensitive enteropathy characterized by a marked infiltration of the mucosa with immune cells, over-production of inflammatory cytokines and epithelial cell damage. The factors/mechanisms that sustain and amplify the ongoing mucosal inflammation in CD are not however fully understood. Here, we have examined whether in CD there is a defective clearance of apoptotic cells/bodies, a phenomenon that helps promote tolerogenic signals thus liming pathogenic responses. Accumulation of apoptotic cells and bodies was more pronounced in the epithelial and lamina propria compartments of active CD patients as compared to inactive CD patients and normal controls. Expression of scavenger receptors, which are involved in the clearance of apoptotic cells/bodies, namely thrombospondin (TSP)-1, CD36 and CD61, was significantly reduced in active CD as compared to inactive CD and normal mucosal samples. Consistently, lamina propria mononuclear cells (LPMC) of active CD patients had diminished ability to phagocyte apoptotic cells. Interleukin (IL)-15, IL-21 and interferon-γ, cytokines over-produced in active CD, inhibited the expression of TSP-1, CD36, and CD61 in normal intestinal LPMC. These results indicate that CD-related inflammation is marked by diminished clearance of apoptotic cells/bodies, thus suggesting a role for such a defect in the ongoing mucosal inflammation in this disorder.

Biological therapy for dermatological manifestations of inflammatory bowel disease.

Ulcerative colitis and Crohn's disease are the two forms of inflammatory bowel disease (IBD). The advent of biological drugs has significantly changed the management of these conditions. Skin manifestations are not uncommon in IBD. Among the reactive lesions (immune-mediated extraintestinal manifestations), erythema nodosum (EN) and pyoderma gangrenosum (PG) are the two major cutaneous ills associated with IBD, while psoriasis is the dermatological comorbidity disease observed more often. In particular, in the last few years, anti-tumor necrosis factor (TNF)-α agents have been successfully used to treat psoriasis, especially these kinds of lesions that may occur during the treatment with biological therapies. The entity of the paradoxical manifestations has been relatively under reported as most lesions are limited and a causal relationship with the treatment is often poorly understood. The reason for this apparent side-effect of the therapy still remains unclear. Although side effects may occur, their clinical benefits are undoubted. This article reviews the therapeutic effects of the two most widely used anti-TNF-α molecules, infliximab (a fusion protein dimer of the human TNF-α receptor) and adalimumab (a fully human monoclonal antibody to TNF-α), for the treatment of the major cutaneous manifestations associated with IBD (EN, PG and psoriasis).

Lesional accumulation of CD163-expressing cells in the gut of patients with inflammatory bowel disease.

Monocytes/macrophages displaying different markers of activation/differentiation infiltrate the inflamed gut of patients with inflammatory bowel diseases (IBD), but the role that each monocyte/macrophage subpopulation plays in the pathogenesis of IBD is not fully understood. The hemoglobin scavenger receptor CD163, a specific marker of monocytes/macrophages, has been associated with either anti-inflammatory or inflammatory functions of macrophages in several pathologies. In this study we examined the tissue distribution and function of CD163-expressing monocytes/macrophages in IBD. CD163 RNA and protein expression was more pronounced in IBD in comparison to normal controls, with no significant difference between Crohn's disease and Ulcerative colitis. In IBD, over-expression of CD163 was restricted to areas with active inflammation and not influenced by current therapy. Immunohistochemical analysis confirmed the accumulation of CD163-expressing cells in IBD, mostly around and inside blood vessels, thus suggesting that these cells are partly recruited from the systemic circulation. Indeed, FACS analysis of circulating mononuclear cells showed that the fractions of CD163-positive monocytes were increased in IBD patients as compared to controls. Functionally, interleukin-6 up-regulated CD163 expression in lamina propria mononuclear cells and mucosal explants of normal subjects. In IBD blood and mucosal cell cultures, cross-linking of CD163 with a specific monoclonal anti-CD163 antibody enhanced tumor necrosis factor-α synthesis. These findings indicate that IBD mucosa is abundantly infiltrated with CD163-positive cells, which could contribute to amplify the inflammatory cytokine response.

Interleukin-25 fails to activate STAT6 and induce alternatively activated macrophages.

Interleukin-25 (IL-25), a T helper type 2 (Th2) -related factor, inhibits the production of inflammatory cytokines by monocytes/macrophages. Since Th2 cytokines antagonize classically activated monocytes/macrophages by inducing alternatively activated macrophages (AAMs), we here assessed the effect of IL-25 on the alternative activation of human monocytes/macrophages. The interleukins IL-25, IL-4 and IL-13 were effective in reducing the expression of inflammatory chemokines in monocytes. This effect was paralleled by induction of AAMs in cultures added with IL-4 or IL-13 but not with IL-25, regardless of whether cells were stimulated with lipopolysaccharide or interferon-γ. Moreover, pre-incubation of cells with IL-25 did not alter the ability of both IL-4 and IL-13 to induce AAMs. Both IL-4 and IL-13 activated signal transducer and activator of transcription 6 (STAT6), and silencing of this transcription factor markedly reduced the IL-4/IL-13-driven induction of AAMs. In contrast, IL-25 failed to trigger STAT6 activation. Among Th2 cytokines, only IL-25 and IL-10 were able to activate p38 mitogen-activated protein kinase. These results collectively indicate that IL-25 fails to induce AAMs and that Th2-type cytokines suppress inflammatory responses in human monocytes by activating different intracellular signalling pathways.

Targeting IL-23 and Th17-cytokines in inflammatory bowel diseases.

Over the last 15 years, the use of various biological therapies has largely improved the way we manage patients with Inflammatory Bowel Diseases (IBDs). Blockade of cytokine synthesis and/or activity is at the forefront of this new era with the success of inhibitors of tumor necrosis factor (TNF)-α. These therapies are however not effective in all IBD patients and efficacy may wane. Moreover, patients treated with anti-TNF-α antibodies can develop severe side-effects and new immune-mediated diseases. Therefore, a new challenge is to elucidate new inflammatory networks in the IBD tissue and develop novel anti-cytokine compounds, which may act in patients who are resistant to or cannot receive anti-TNF-α therapies. In this article we review the available data supporting the pathogenic role of IL-23 and Th17-related cytokines in IBD, and discuss whether and how compounds that control the activity of these cytokines may enter into the therapeutic armamentarium of IBD.

Interleukin-21 triggers effector cell responses in the gut.

In the gut of patients with Crohn's disease and patients with ulcerative colitis, the major forms of inflammatory bowel diseases (IBD) in humans, the tissue-damaging immune response is mediated by an active cross-talk between immune and non-immune cells. Accumulating evidence indicates also that cytokines produced by these cells play a major role in initiating and shaping this pathologic process. One such cytokine seems to be interleukin (IL)-21, a member of the common gamma-chain-receptor family. IL-21 is produced in excess in the inflamed intestine of patients with IBD mostly by activated CD4+ T helper cells co-expressing interferon-gamma and follicular T helper cells. Moreover, both in vitro and in vivo studies indicate that excessive IL-21 production leads to the activation of multiple signaling pathways that expand and sustain the ongoing mucosal inflammation. In this article, we review the available data supporting the pathogenic role of IL-21 in IBD.

Organ culture system as a means to detect celiac disease.

Anti-endomysial and anti-transglutaminase antibodies can be produced in vitro by the intestinal mucosa of celiac disease (CD) patients in clinical remission, when the culture is performed in the presence of gliadin peptides. Our aim was to use this organ culture system as a means to detect the pathognomonic antibodies of celiac disease (CD) in the culture supernatants. Organ culture was performed in the presence of three different activators to evaluate which one induced the strongest antibody response in intestinal mucosa from patients in clinical remission of CD. Our data confirm the high efficiency of synthetic peptide 31-43 as a specific immunological activator in CD and demonstrate its capability to stimulate production/secretion of CD-specific antibodies. We envision that this organ culture system may prove to be useful as a new technique for CD diagnosis.

Involvement of interleukin-15 and interleukin-21, two gamma-chain-related cytokines, in celiac disease.

Celiac disease (CD), an enteropathy caused by dietary gluten in genetically susceptible individuals, is histologically characterized by villous atrophy, crypt cell hyperplasia, and increased number of intra-epithelial lymphocytes. The nature of CD pathogenesis remains unclear, but recent evidence indicates that both innate and adaptive immune responses are necessary for the phenotypic expression and pathologic changes characteristic of CD. Extensive studies of molecules produced by immune cells in the gut of CD patients have led to identification of two cytokines, namely interleukin (IL)-15 and IL-21, which are thought to play a major role in orchestrating the mucosal inflammatory response in CD. Here we review the current knowledge of the expression and function of IL-15 and IL-21 in CD.

High incidence of celiac disease in patients with systemic sclerosis.

OBJECTIVE: To evaluate the presence of celiac disease in patients with systemic sclerosis (SSc). The association of autoimmune diseases with celiac disease has been reported, but few publications deal with the combination of SSc and celiac disease. METHODS: We investigated the presence of anti-tissue transglutaminase (anti-tTG) antibodies and serum antiendomysial antibodies (anti-EMA) in 50 patients with SSc. All subjects were on a gluten-containing diet. Duodenal mucosa histology and biopsy culture were performed in anti-tTG-positive patients; anti-EMA and IgA, IgG1 anti-tTG were detected in culture supernatants. RESULTS: The incidence of celiac disease in patients with SSc was found to be 8%. Serum anti-tTG antibody-positive results were detectable in 5 out of 50 patients with SSc, but only in 4 of them was the diagnosis confirmed by histological results (Marsh classification). CONCLUSION: Our data show an increased prevalence of celiac disease in patients with SSc.