Epigenetic silencing of SOCS3 expression contributes to fibrosis in Crohn’s disease

Identified risk polymorphisms affecting the Jak-STAT3 pathway in patients with Crohn’s disease could affect TGF-β1 and collagen I expression and in the pathway’s negative regulator, SOCS3. Genetic factors, however, account for only ~25% of disease. Epigenetic events also shape gene expression. Recent experiments showed that autocrine IL-6 production in mesenchymal cells, subepithelial myofibroblasts (SEMF) and muscle cells, of patients with fibrostenotic Crohn’s disease causes sustained Jak-STAT3 activity, excess TGF-β1 and Collagen I production and fibrosis. SOCS3 paradoxically decreased in these cells. We now identify epigenetic mechanisms that silence SOCS3 expression in SEMF of patients with fibrostenotic Crohn’s disease. In a previous experiment, using isolated SEMF of normal ileum and affected ileum from patients with each Crohn’s phenotype, inflammatory (Montreal B1), fibrostenotic (B2) and penetrating (B3), we confirmed decreased SOCS3 protein levels were unique to B2 patients. Expression of miR-19b increased in SEMF of affected ileum. SOCS3 transcriptional activity decreased after transfection of miR-19b mimic and increased when antagomiR-19b was expressed. Epigenetic silencing of SOCS3 in ileal SEMF of patients with fibrostenotic Crohn’s disease occurs by increased miR-19b mediated inhibition of SOCS3

Understanding the Role of Phosphoinositide 3-Kinase and its Function as a Driving Force behind the ER Stress Response in Fibrostenotic Crohn’s Disease-affected Ileal Smooth Muscle Cells

Crohn’s disease (CD) affects about 780,000 people in the United States alone, and it is estimated that 6-15 per 100,000 persons will receive a diagnosis of this disease each year. There currently is no cure for Crohn’s disease, and available medical therapies simply serve to alleviate the inflammation. This does not help treat fibrostenosis that Crohn’s disease patients may develop, which can only be treated surgically. Finding alternatives to treat CD requires an understanding of mechanisms at the biochemical level. In this thesis, we attempted to gain a better understanding of certain pathways found to be active in Crohn’s disease-affected ileal smooth muscle cells. We found an upregulation of the ER stress pathway via expression of its surrogate, the GRP78 protein. We also showed evidence that the phosphoinositide 3-kinase (PI3K) pathway, a key proliferative pathway, is linked to ER stress in these cells, and is an upstream driving force of the ER stress response. Further research on the link between the PI3K and ER stress pathways needs to be conducted, and can potentially serve as a target for therapeutics to help reduce proliferation in fibrostenotic Crohn’s disease-affected ileal smooth muscle cells

Detecting and managing small bowel Crohn’s disease – capsule endoscopy becoming a first line diagnostic method?

Small bowel endoscopy is crucial for diagnosing small bowel Crohn’s disease, and capsule endoscopy is complemented by balloon-assisted enteroscopy to take biopsies and by magnetic resonance imaging to visualize enteral and extra-intestinal involvement. Recently, imaging has also become a key instrument to manage Crohn’s disease patients. Treatment control is advised for patients who have undergone bowel resections and is increasingly used to testify treatment success in non-operated patients, too. In this review we present the modern imaging methods to diagnose and to manage Crohn’s disease with a special focus on the small bowel. Moreover, current knowledge on the impact of diagnostic methods on the patients’ outcome is reported

Smoking in inflammatory bowel diseases: Good, bad or ugly?

Smoking is an important environmental factor in inflammatory bowel disease (IBD), having different effects in ulcerative colitis (UC) and Crohn’s disease (CD). A recent meta-analysis partially confirmed previous findings that smoking was found to be protective against ulcerative colitis and, after onset of the disease, might improve its course, decreasing the need for colectomy. However, smoking increases the risk of developing Crohn’s disease and worsens its course, increasing the need for steroids, immunosuppressants and re-operations. Smoking cessation aggravates ulcerative colitis and improves Crohn’s disease. Data are however, largely conflictive as well as the potential mechanisms involved in this dual relationship are still unknown. In this review article, the authors review the role of smoking in inflammatory bowel diseases

Crohn’s disease

44-year-old female known case of Crohn’s disease and depression who presented with a few hours’ history of severe abdominal pain and multiple episodes of vomiting faeculant matter. An inflamed terminal ileum and ascending colon were found at laparatomy and resection of terminal ileum and caecum (right hemicolectomy) was carried out. Crohn’s is a chronic inflammatory bowel disorder of unknown aetiology which can affect the whole gastrointestinal system (from mouth to anus) and is typified by asymmetric, focal, transmural inflammation and sometimes granuloma formation in the bowel wall. Signs of extraintestinal manifestation can be marked. The life-long disease is punctuated by periods of exacerbation and remission15. Genetic and environmental contributors, as well as immunological factors are implicated in the pathogenesis and severity of Crohn’s disease.peer-reviewe

Radiological sacroiliitis, a hallmark of spondylitis, is linked with CARD15 gene polymorphisms in patients with Crohn's disease

Background: Sacroiliitis is a common extraintestinal manifestation of Crohn's disease but its association with the HLA-B27 phenotype is less evident. Polymorphisms in the CARD15 gene have been linked to higher susceptibility for Crohn's disease. In particular, associations have been found with ileal and fibrostenosing disease, young age at onset of disease, and familial cases. Objectives: To investigate whether the presence of sacroiliitis in patients with Crohn's disease is linked to the carriage of CARD15 polymorphisms. Methods: 102 consecutive patients with Crohn's disease were clinically evaluated by a rheumatologist. Radiographs of the sacroiliac joints were taken and assessed blindly by two investigators. The RFLP-PCR technique was used to genotype all patients for three single nucleotide polymorphisms (SNP) in the CARD15 gene. Every SNP was verified by direct sequencing. The HLA-B27 phenotype was determined. Results: Radiological evidence of sacroiliitis with or without ankylosing spondylitis was found in 23 patients (23%), of whom only three were HLA-B27 positive. In contrast, 78% of patients with sacroiliitis carried a CARD15 variant v 48% of those without sacroiliitis (p = 0.01; odds ratio 3.8 (95% confidence interval, 1.3 to 11.5)). Multivariate analysis (logistic regression) showed that the association between sacroiliitis and CARD15 polymorphisms was independent of other CARD15 related phenotypes (ileal and fibrostenosing disease, young age at onset of disease, familial Crohn's disease) (p = 0.039). Conclusions: CARD15 variants were identified as genetic predictors of Crohn's disease related sacroiliitis. An association was demonstrated between these polymorphisms and an extraintestinal manifestation of Crohn's disease

Crohn's disease: Th1, Th17 or both? The change of a paradigm: new immunological and genetic insights implicate Th17 cells in the pathogenesis of Crohn's disease

Traditionally, Crohn's disease has been associated with a Th1 cytokine profile, while Th2 cytokines are modulators of ulcerative colitis. This concept has been challenged by the description of tolerising regulatory T cells (Treg) and by proinflammatory Th17 cells, a novel T cell population characterised by the master transcription factor ROR\textgreekgt, the surface markers IL23R and CCR6, and by production of the proinflammatory cytokines IL17A, IL17F, IL21, IL22 and IL26, and the chemokine CCL20. Th17 cells differentiate under the influence of IL1\textgreekb, IL6, IL21 and IL23. Recent studies indicate that TGF\textgreekb is essential not only for the development of murine Th17 cells but also for differentiation of human Th17 cells. TGF\textgreekb reciprocally regulates the differentiation of inflammatory Th17 cells and suppressive Treg subsets, with the concomitant presence of proinflammatory cytokines favouring Th17 cell differentiation. Several studies demonstrated an important role of Th17 cells in intestinal inflammation, particularly in Crohn's disease. Genome-wide association studies indicate that IL23R and five additional genes involved in Th17 differentiation (IL12B, JAK2, STAT3, CCR6 and TNFSF15) are associated with susceptibility to Crohn's disease and partly also to ulcerative colitis. Taken together, both Th1 and Th17 cells are important mediators of inflammation in Crohn's disease, although activities previously ascribed to IL12 may be mediated by IL23. Anti-IL12/IL23p40 antibody therapy, which targets both Th1 and Th17 cells, is effective in Crohn's disease. However, the complex relationship between Th1 and Th17 cells has not been completely analysed. This will be of great importance to delineate the specific contributions of these cells to Crohn's disease and other autoimmune diseases

Alterations of the CARD15/NOD2 gene and the impact on management and treatment of Crohn's disease patients

The recent identification of the CARD15/NOD2 gene as a susceptibility locus for Crohn's disease represents an important step towards the delineation of the immuno-pathogenesis of inflammatory bowel disease. CARD15 functions as an intracellular receptor for bacterial components and thus represents an important link between inflammatory bowel disease and innate immunity. Three major CARD15/NOD2 gene mutations have been associated with Crohn's disease in Caucasians in several independent studies. Together, they explain about 20% of the genetic susceptibility for Crohn's disease. Genotype-phenotype analyses demonstrated an association of these mutations with ileum-specific disease, an increased incidence of the fibrostenotic phenotype and an earlier age of disease onset. Beside these associations, no other relationship between the CARD15/NOD2 genotype and disease behavior or response to treatment has been detailed so far. Thus, the clinical impact of knowing the patient's genotype is limited at this time. Screening for CARD15 mutations in order to identify high-risk individuals or to introduce an individualized disease management is therefore currently not recommended. Copyright (C) 2003 S. Karger AG, Basel

Topical tacrolimus 0.1% ointment for treatment of cutaneous Crohn's Disease

Peer reviewedPublisher PD

Azathioprine and 6-mercaptopurine for maintenance of surgically-induced remission in Crohn’s disease

Background Crohn’s disease (CD) is a chronic relapsing inflammatory condition. Many patients fail to achieve remission with medical management and require surgical interventions. Purine analogues have been used to maintain surgically-induced remission in CD, but the effectiveness of these agents is unclear. Objectives The objectives were to evaluate the efficacy and safety of purine analogues for maintenance of surgically-induced remission in CD. Search methods We searched the following databases from inception to 30 April 2014: PubMed, MEDLINE, EMBASE, CENTRAL, and the Cochrane Inflammatory Bowel Disease and Functional Bowel Disorders Group Specialized Trials Register).We also searched the reference lists of all included studies, and contacted personal sources and drug companies to identify additional studies. The searches were not limited by language. Selection criteria Randomised controlled trials (RCTs) that compared purine analogues to placebo or another intervention, with treatment durations of at least six months were considered for inclusion. Participants were patients of any age with CD in remission following surgery. Data collection and analysis Two authors independently assessed trial eligibility and extracted data. Methodological quality was assessed using the Cochrane risk of bias tool. The primary outcome measures were clinical and endoscopic relapse as defined by the primary studies. Secondary outcomes included adverse events, withdrawal due to adverse events and serious adverse events. Data were analysed on an intention-to-treat basis where patients with missing final outcomes were assumed to have relapsed. We calculated the risk ratio (RR) and corresponding 95% confidence interval (95% CI) for dichotomous outcomes. The Chi2 and I2 statistics were used to assess heterogeneity. The overall quality of the evidence supporting the primary outcomes and selected secondary outcomes was assessed using the GRADE criteria. Main results Seven RCTs (n = 584 patients) were included in the review. Three studies compared azathioprine to 5-aminosalicylic acid (5-ASA).One small study compared azathioprine to both 5-ASA and adalimumab. One study compared azathioprine to placebo and another study compared 6-mercaptopurine to 5-ASA and placebo. One small study compared azathioprine to infliximab. Three studies were judged to be at low risk of bias. Four studies were judged to be at high risk of bias due to blinding. The study (n = 22) comparing azathioprine to infliximab found that the effects on the proportion of patients who had a clinical (RR 2.00, 95% CI 0.21 to 18.98) or endoscopic relapse (RR 4.40, 95% CI 0.59 to 3.07) were uncertain. One study (n = 33) found decreased clinical (RR 5.18, 95% CI 1.35 to 19.83) and endoscopic relapse (RR 10.35, 95% CI 1.50 to 71.32) rates favouring adalimumab over azathioprine. A pooled analysis of two studies (n = 168 patients) showed decreased clinical relapse rates at one or two years favouring purine analogues over placebo. Forty eight per cent of patients in the purine analogue group experienced a clinical relapse compared to 63% of placebo patients (RR 0.74, 95% CI 0.58 to 0.94). A GRADE analysis indicated that the overall quality of the evidence supporting this outcome was low due to high risk of bias (one study was single-blind) and sparse data (93 events). One study (87 patients) found a reduction in endoscopic relapse rates favouring 6-mercaptopurine over placebo. Seventeen per cent of 6-mercaptopurine patients had an endoscopic relapse at two years compared to 42% of placebo patients (RR 0.40, 95% CI 0.19 to 0.83). A GRADE analysis indicated that the overall quality of the evidence for this outcome was low due to very sparse data (25 events). A pooled analysis of five studies (n = 425 patients) showed no difference in clinical relapse rates at one or two years between purine analogues and 5-ASA agents. Sixty-three per cent of patients in the purine analogues group experienced a clinical relapse compared to 54% of 5-ASA patients (RR 1.15, 95% CI 0.99 to 1.34). A GRADE analysis indicated that the overall quality of the evidence supporting this outcome was very low due to high risk of bias (two open-label studies), sparse data (249 events) and moderate heterogeneity (I2 = 45%). There was no difference in endoscopic relapse at 12 months between azathioprine and 5-ASA (RR 0.78, 95% CI 0.52 to 1.17; 1 study, 35 patients). A GRADE analysis indicated that the overall quality of the evidence for this outcome was very low due to high risk of bias (open-label study) and very sparse data (26 events). There was a reduction in endoscopic relapse at 24 months favouring 6-mercaptopurine over 5-ASA patients. Seventeen per cent of 6-mercaptopurine patients had an endoscopic relapse compared to 48% of 5-ASA patients (RR 0.36, 95% CI 0.18 to 0.72; 1 study, 91 patients). A GRADE analysis indicated that the overall quality of the evidence for this outcome was low due to very sparse data (29 events). Adverse events that required withdrawal were more common in the purine analogue group compared to 5-ASA. Twenty per cent of patients in the purine analogue group withdrew due to adverse events compared to 10% of 5-ASA patients (RR 2.07, 95% CI 1.26 to 3.39; 5 studies, 423 patients).The results for withdrawal due to adverse events between purine analogues and placebo or for other comparisons were uncertain. Commonly reported adverse events across all studies included leucopenia, arthralgia, abdominal pain or severe epigastric intolerance, elevated liver enzymes, nausea and vomiting, pancreatitis, anaemia, exacerbation of Crohn’s disease, nasopharyngitis, and flatulence. Authors’ conclusions Purine analogues may be superior to placebo for maintenance of surgically-induced remission in patients with CD, although this is based on two small studies. The results for efficacy outcomes between purine analogues and 5-ASA agents were uncertain. However, patients taking purine analogues were more likely than 5-ASA patients to discontinue therapy due to adverse events. No firm conclusions can be drawn from the two small studies that compared azathioprine to infliximab or adalimumab. Adalimumab may be superior to azathioprine but further research is needed to confirm these results. Further research investigating the efficacy and safety of azathioprine and 6-mercaptopurine in comparison to other active medications in patients with surgically-induced remission of CD is warranted