Monitoring inflammatory bowel disease activity: clinical activity is judged to be more relevant than endoscopic severity or biomarkers.

BACKGROUND: There is increasing evidence for the clinical relevance of mucosal healing (MH) as therapeutic treatment goal in inflammatory bowel disease (IBD). We aimed to investigate by which method gastroenterologists monitor IBD activity in daily practice. METHODS: A questionnaire was sent to all board-certified gastroenterologists in Switzerland to specifically address their strategy to monitor IBD between May 2009 and April 2010. RESULTS: The response rate was 57% (153/270). Fifty-two percent of gastroenterologists worked in private practice and 48% worked in hospitals. Seventy-eight percent judged clinical activity to be the most relevant criterion for monitoring IBD activity, 15% chose endoscopic severity, and 7% chose biomarkers. Seventy percent of gastroenterologists based their therapeutic decisions on clinical activity, 24% on endoscopic severity, and 6% on biomarkers. The following biomarkers were used for IBD activity monitoring: CRP, 94%; differential blood count, 78%; fecal calprotectin (FC), 74%; iron status, 63%; blood sedimentation rate, 3%; protein electrophoresis, 0.7%; fecal neutrophils, 0.7%; and vitamin B12, 0.7%. Gastroenterologists in hospitals and those with ≤ 10 years of professional experience used FC more frequently compared with colleagues in private practice (P=0.035) and those with > 10 years of experience (P<0.001). CONCLUSIONS: Clinical activity is judged to be more relevant for monitoring IBD activity and guiding therapeutic decisions than endoscopic severity and biomarkers. As such, the accumulating scientific evidence on the clinical impact of mucosal healing does not yet seem to influence the management of IBD in daily gastroenterologic practice.

High altitude journeys and flights are associated with an increased risk of flares in inflammatory bowel disease patients.

BACKGROUND AND AIMS: Hypoxia can induce inflammation in the gastrointestinal tract. However, the impact of hypoxia on the course of inflammatory bowel disease (IBD) is poorly understood. We aimed to evaluate whether flights and/or journeys to regions lying at an altitude of >2000 m above the sea level are associated with flare-ups within 4 weeks of the trip. METHODS: IBD patients with at least one flare-up during a 12-month observation period were compared to a group of patients in remission. Both groups completed a questionnaire. RESULTS: A total of 103 IBD patients were included (43 with Crohn's disease (CD): mean age 39.3 ± 14.6 years; 60 with ulcerative colitis (UC): mean age 40.4 ± 15.1 years). Fifty-two patients with flare-ups were matched to 51 patients in remission. IBD patients experiencing flare-ups had more frequently undertaken flights and/or journeys to regions >2000 m above sea level within four weeks of the flare-up when compared to patients in remission (21/52 [40.4%] vs. 8/51 [15.7%], p=0.005). CONCLUSIONS: Journeys to high altitude regions and/or flights are a risk factor for IBD flare-ups occurring within 4 weeks of travel.

Monitoring de l'immunosuppression par les thiopurines dans les maladies inflammatoires chroniques de l'intestin par le suivi de la macrocytose

Background¦Erythrocyte MCV might be used as an inexpensive marker to predict and¦optimize the efficacy and tolerability of thiopurine therapy in IBD patients.¦Aim and methods¦This retrospective observational study aimed to assess the monitoring¦performances of MCV in patients under 3 months or more thiopurine treatment followed up¦in the Swiss IBD Cohort Study. All available MCV, white blood cells (WBC) and 6¦thioguanine nucleotide (6TGN) measurements, among others, were recorded. An IBD¦"flare" was defined as a composite outcome encompassing treatment change,¦colonoscopy, histology, CT scan or MRI reports showing active IBD lesions, occurrence of¦intestinal surgery and IBD-related hospitalisations. Whether MCV measurements predicted¦efficacy of thiopurine treatment was investigated by assessing the statistical association¦between the occurrence of IBD "flares", and the current or recent MCV values, taking into¦account the patient clustering and longitudinal aspect of data.¦Results¦140 patients (77 women), mean age 38 years (17-74), 104 diagnosed with¦Crohn's disease, 36 with ulcerative colitis, mean disease duration 8 years (0.25-36),¦receiving either azathioprine (n=125) or 6-mercaptopurine (n=15) were included, most of¦them over 3-year follow up.¦Thiopurines increased mean patient MCV by an average 5.8±5.2 fL, while¦patientsfluctuated by ±4.3 fL around their individual mean (p<0.001). They decreased¦WBC by an average of 2.4+/- 2.6 G/L (p<0.001).¦Significant associations were observed between the probability of flare occurrence and low¦current MVC (p=0.017) or high current WBC (p=0.009) and, with a relative risk of 3.7% for¦every fL of MCV decrease or 8% for every G/L of WBC increase. Both markers revealed¦some memory effect.¦Despite this, the performance of MCV and WBC to predict IBD "flare" remained rather¦limited, as it is less accurate than the 6-TGN-level , although only determined in a¦subgroup of patients in this study.¦Conclusion¦MCV and WBC deserve to be observed to check and monitor therapeutic¦exposure to thiopurine agents in IBD patients. Unfortunately, their predictive performance¦precludes their privileged use for optimization of therapy. Further prospective studies¦should suitably include the systematic measurement of metabolite concentration.

Acceptance of inflammatory bowel disease treatment recommendations based on appropriateness ratings : do practicing gastroenterologists agree with experts?

BACKGROUND: Appropriateness criteria for the treatment of Crohn's disease (CD) and ulcerative colitis (UC) have been developed by experts' panels. Little is known about the acceptance of such recommendations by care providers. The aim was to explore how treatment decisions of practicing gastroenterologists differ from experts using a vignette case study and a focus group. METHODS: Seventeen clinical vignettes were drawn from clinical indications evaluated by the expert panel. A vignette case questionnaire asking for treatment options in 9-10 clinical situations was submitted to 26 practicing gastroenterologists. For each vignette case, practitioners' answers on treatments deemed appropriate were compared to panel decisions. Qualitative analysis was made based on focus group discussion to explore acceptance and divergence reasons. RESULTS: 239 clinical vignettes were completed, 98 for CD and 141 for UC. Divergence between proposed treatments and results from panels was more frequent for CD (34%) than for UC (27%). Among UC clinical vignettes, the main divergences with the panel were linked to 5-ASA failure assessment and to situations where stopping treatment was the main decision. For CD, the care provider propositions diverged with the panel in mild-to-moderate active disease, where practitioners were more prone to an accelerated step up than the panel's recommendations. CONCLUSIONS: In about one third of vignettes cases, IBD treatment propositions made by practicing gastroenterologists diverged as compared to expert recommendations. Practicing gastroenterologists may experience difficulties in applying recommendations in daily practice.

Appropriateness of colonoscopy in Europe (EPAGE II). Chronic diarrhea and known inflammatory bowel disease.

BACKGROUND AND STUDY AIMS: To summarize the published literature on assessment of appropriateness of colonoscopy for investigation of chronic diarrhea, management of patients with known inflammatory bowel disease (IBD), and for colorectal cancer (CRC) surveillance in such patients, and to report report appropriateness criteria developed by an expert panel, the 2008 European Panel on the Appropriateness of Gastrointestinal Endoscopy, EPAGE II. METHODS: A systematic search of guidelines, systematic reviews, and primary studies regarding the evaluation of chronic diarrhea, the management of IBD, and colorectal cancer surveillance in IBD was performed. The RAND/UCLA Appropriateness Method was applied to develop appropriateness criteria for colonoscopy for these conditions. RESULTS: According to the literature, colonoscopic evaluation may be justified for patients aged > 50 years with recent-onset chronic diarrhea or with alarm symptoms. Surveillance colonoscopy for CRC should be offered to all patients with extensive ulcerative colitis or colonic Crohn's disease of 8 years' duration, and to all patients with less extensive disease of 15 years' duration. Intervals for surveillance colonoscopy depend on duration of evolution, initial diagnosis, and histological findings. The EPAGE II criteria also confirmed the appropriateness of diagnostic colonoscopy for diarrhea of > 4 weeks' duration. They also suggest that, in addition to assessing extent of IBD by colonoscopy, further colonoscopic examination is appropriate in the face of persistent or worsening symptoms. Surveillance colonoscopy in IBD patients was generally appropriate after a lapse of 2 years. In the presence of dysplasia at previous colonoscopy, it was not only appropriate but necessary. CONCLUSIONS: Despite or perhaps because of the limitations of the available published studies, the panel-based EPAGE II (http://www.epage.ch) criteria can help guide appropriate colonoscopy use in the absence of strong evidence from the literature.

Malt1 protease inactivation efficiently dampens immune responses but causes spontaneous autoimmunity.

The protease activity of the paracaspase Malt1 has recently gained interest as a drug target for immunomodulation and the treatment of diffuse large B-cell lymphomas. To address the consequences of Malt1 protease inactivation on the immune response in vivo, we generated knock-in mice expressing a catalytically inactive C472A mutant of Malt1 that conserves its scaffold function. Like Malt1-deficient mice, knock-in mice had strong defects in the activation of lymphocytes, NK and dendritic cells, and the development of B1 and marginal zone B cells and were completely protected against the induction of autoimmune encephalomyelitis. Malt1 inactivation also protected the mice from experimental induction of colitis. However, Malt1 knock-in mice but not Malt1-deficient mice spontaneously developed signs of autoimmune gastritis that correlated with an absence of Treg cells, an accumulation of T cells with an activated phenotype and high serum levels of IgE and IgG1. Thus, removal of the enzymatic activity of Malt1 efficiently dampens the immune response, but favors autoimmunity through impaired Treg development, which could be relevant for therapeutic Malt1-targeting strategies.

Analysis of TNF-antagonist switch over time and associated risk factors in the Swiss Inflammatory Bowel Disease Cohort

Abstract Background and aims. Limited data from large cohorts are available on tumor necrosis factor (TNF) antagonists (infliximab, adalimumab, certolizumab pegol) switch over time. We aimed to evaluate the prevalence of switching from one TNF antagonist to another and to identify associated risk factors. Methods. Data from the Swiss Inflammatory Bowel Diseases Cohort Study (SIBDCS) were analyzed. Results. Of 1731 patients included into the SIBDCS (956 with Crohn's disease [CD] and 775 with ulcerative colitis [UC]), 347 CD patients (36.3%) and 129 UC patients (16.6%) were treated with at least one TNF antagonist. A total of 53/347 (15.3%) CD patients (median disease duration 9 years) and 20/129 (15.5%) of UC patients (median disease duration 7 years) needed to switch to a second and/or a third TNF antagonist, respectively. Median treatment duration was longest for the first TNF antagonist used (CD 25 months; UC 14 months), followed by the second (CD 13 months; UC 4 months) and third TNF antagonist (CD 11 months; UC 15 months). Primary nonresponse, loss of response and side effects were the major reasons to stop and/or switch TNF antagonist therapy. A low body mass index, a short diagnostic delay and extraintestinal manifestations at inclusion were identified as risk factors for a switch of the first used TNF antagonist within 24 months of its use in CD patients. Conclusion. Switching of the TNF antagonist over time is a common issue. The median treatment duration with a specific TNF antagonist is diminishing with an increasing number of TNF antagonists being used.

Prevalence of Inflammatory Bowel Disease in the Canton of Vaud (Switzerland): A population-based cohort study

Background and aims: Because of the changing epidemiology of Inflammatory Bowel Diseases 0131)), we set out to characterize the population-based prevalence of Crohn's Disease (CD) and Ulcerative Colitis (UC) in a defined population of Switzerland. Methods: Adult IBD patients were identified by a cross-matched review of histological, hospital and gastroenterologist files throughout a geographical defined population (Canton of Vaud). Demographic factors statistically significantly associated with prevalence were evaluated using a stepwise Poisson regression analysis. Results were compared to IBD prevalence rates in other population-based studies and time trends were performed, based on a systematic literature review. Results: Age and sex-adjusted prevalence rates were 205.7 IBD (100.7 CD and 105.0 UC) cases per 105 inhabitants. Among 1016 IBD patients (519 CD and 497 UC), females outnumbered mates in CD (p < 0.001), but mates were more represented in elderly UC patients (p = 0.008). Thus, being a mate was statistically associated with UC (Relative Risk (RR) 1.25; p = 0.013), whereas being a female was associated with CD (RR 1.27; p = 0.007). Living in an urban zone was associated with both CD and UC (RR 1.49; p < 0.001, 1.63; p < 0.001, respectively). From 1960 to 2005, increases in UC and CD prevalences of 2.4% (95%CI, 2.1%-2.8%; p < 0.001) and 3.6% (95%CI, 3.1%-4.1%; p < 0.001) per annum were found in industrialised countries.

Maintenance of remission in Crohn's disease.

When remission of Crohn's disease is achieved, the next goal is to maintain long-term remission. Aminosalicylates may be recommended for maintenance remission, even though the results are less consistent than those observed in ulcerative colitis. The benefit is mainly observed in the post-surgical setting and in patients with ileitis, and with a prolonged disease duration. Corticosteroids are not effective in maintaining remission and should not be used for this indication. Azathioprine and 6-mercaptopurine are effective in maintaining remission. Maintenance benefits remain significant for patients who continued with the therapy for up to 5 years. Methotrexate has also been found to be effective in maintaining remission in Crohn's disease in patients who have responded acutely to methotrexate. Cyclosporine has not been found to be an effective maintenance agent. Mycophenolate mofetil could be considered a therapy in patients who are either allergic to azathioprine or in whom azathioprine failed to induce remission. The use of infliximab may change the future approach to maintenance therapy for Crohn's disease. Patients who responded clinically to infliximab have maintained their clinical response when receiving repeat infusions at 8-week intervals. In patients refractory to other therapies, infliximab may be effective in maintaining remission.

Granulocyte-macrophage colony-stimulating factor elicits bone marrow-derived cells that promote efficient colonic mucosal healing.

BACKGROUND: Granulocyte-macrophage colony-stimulating factor (GM-CSF) therapy is effective in treating some Crohn's disease (CD) patients and protects mice from colitis induced by dextran sulfate sodium (DSS) administration. However, its mechanisms of action remain elusive. We hypothesized that GM-CSF affects intestinal mucosal repair. METHODS: DSS colitic mice were treated with daily pegylated GM-CSF or saline and clinical, histological, and inflammatory parameters were kinetically evaluated. Further, the role of bone marrow-derived cells in the impact of GM-CSF therapy on DSS colitis was addressed using cell transfers. RESULTS: GM-CSF therapy reduced clinical signs of colitis and the release of inflammatory mediators. GM-CSF therapy improved mucosal repair, with faster ulcer reepithelialization, accelerated hyperproliferative response of epithelial cells in ulcer-adjacent crypts, and lower colonoscopic ulceration scores in GM-CSF-administered mice relative to untreated mice. We observed that GM-CSF-induced promotion of mucosal repair is timely associated with a reduction in neutrophil numbers and increased accumulation of CD11b(+) monocytic cells in colon tissues. Importantly, transfer of splenic GM-CSF-induced CD11b(+) myeloid cells into DSS-exposed mice improved colitis, and lethally irradiated GM-CSF receptor-deficient mice reconstituted with wildtype bone marrow cells were protected from DSS-induced colitis upon GM-CSF therapy. Lastly, GM-CSF-induced CD11b(+) myeloid cells were shown to promote in vitro wound repair. CONCLUSIONS: Our study shows that GM-CSF-dependent stimulation of bone marrow-derived cells during DSS-induced colitis accelerates colonic tissue repair. These data provide a putative mechanism for the observed beneficial effects of GM-CSF therapy in Crohn's disease.

Peroxisome proliferator-activated receptor gamma activation is required for maintenance of innate antimicrobial immunity in the colon.

Crohn's disease (CD), a major form of human inflammatory bowel disease, is characterized by primary immunodeficiencies. The nuclear receptor peroxisome proliferator-activated receptor gamma (PPARgamma) is essential for intestinal homeostasis in response to both dietary- and microbiota-derived signals. Its role in host defense remains unknown, however. We show that PPARgamma functions as an antimicrobial factor by maintaining constitutive epithelial expression of a subset of beta-defensin in the colon, which includes mDefB10 in mice and DEFB1 in humans. Colonic mucosa of Ppargamma mutant animals shows defective killing of several major components of the intestinal microbiota, including Candida albicans, Bacteroides fragilis, Enterococcus faecalis, and Escherichia coli. Neutralization of the colicidal activity using an anti-mDefB10 blocking antibody was effective in a PPARgamma-dependent manner. A functional promoter variant that is required for DEFB1 expression confers strong protection against Crohn's colitis and ileocolitis (odds ratio, 0.559; P = 0.018). Consistently, colonic involvement in CD is specifically linked to reduced expression of DEFB1 independent of inflammation. These findings support the development of PPARgamma-targeting therapeutic and/or nutritional approaches to prevent colonic inflammation by restoring antimicrobial immunity in CD.

Intestinal antiinflammatory effect of 5-aminosalicylic acid is dependent on peroxisome proliferator-activated receptor-gamma.

5-aminosalicylic acid (5-ASA) is an antiinflammatory drug widely used in the treatment of inflammatory bowel diseases. It is known to inhibit the production of cytokines and inflammatory mediators, but the mechanism underlying the intestinal effects of 5-ASA remains unknown. Based on the common activities of peroxisome proliferator-activated receptor-gamma (PPAR-gamma) ligands and 5-ASA, we hypothesized that this nuclear receptor mediates 5-ASA therapeutic action. To test this possibility, colitis was induced in heterozygous PPAR-gamma(+/-) mice and their wild-type littermates, which were then treated with 5-ASA. 5-ASA treatment had a beneficial effect on colitis only in wild-type and not in heterozygous mice. In epithelial cells, 5-ASA increased PPAR-gamma expression, promoted its translocation from the cytoplasm to the nucleus, and induced a modification of its conformation permitting the recruitment of coactivators and the activation of a peroxisome-proliferator response element-driven gene. Validation of these results was obtained with organ cultures of human colonic biopsies. These data identify PPAR-gamma as a target of 5-ASA underlying antiinflammatory effects in the colon.

Calprotectine fécale: outil diagnostique dans les maladies inflammatoires chroniques de l'intestin [Fecal calprotectin: a diagnostic tool for inflammatory bowel disease].

Fecal calprotectin (FC) is a valid biomarker to discriminate with a good sensitivity and specificity the presence of mucosal lesions of the gastrointestinal tube (e.g. ulcers in the context of inflammatory bowel disease (IBD)) from functional disorders (e.g. irritable bowel syndrome). FC is not specific for IBD and can be elevated also in gastrointestinal infections, ischemic colitis or neoplasia. An elevated FC should stimulate further investigations, notably an endoscopic workup. The level of FC correlates with the endoscopic score in Crohn's disease and ulcerative colitis. The correlation of FC and the endoscopic severity is better than the one of CRP or blood leukocytes. Thus, FC can also be used in the follow-up of IBD patients.

Association between mannose-binding lectin (MBL) deficiency and cytomegalovirus (CMV) infection after kidney transplantation

MBLdeficiency is thought to be a risk factor for the development of viral infection, such as genital herpes and HSV-2 meningitis. However, there is limited data on the possible interaction between MBL and CMV, especially after organ transplantation. Between 2003 and 2005, we measured MBL levels in 16 kidney transplant recipients with high-risk CMV serostatus (donor positive/recipient negative, D+/R−). All patients receivedCMV prophylaxis of valganciclovir 450 mg/day for 3 months after transplantation. After stopping valganciclovir, CMV-DNA was measured in whole blood by real time PCR every 2 weeks for 3 months. CMV infections were diagnosed according to the recommendations of the AST. MBL levels were measured in stored pre-transplantation sera by an investigator blinded to the CMV complications. MBL levels below 500 ng/ml were considered as being functionally deficient. After a follow-up of at least 10 months, seven patients out of 16 developed CMV disease (three CMV syndrome, and four probable invasive disease, i.e. two colitis and two hepatitis), four patients developed asymptomatic CMV infection, and five patients never developed any sign of CMV replication. Peak CMV-DNA was higher in patients with CMV disease than in those with asymptomatic infection (4.64 versus 2.72 mean log copy CMV-DNA/106 leukocytes, p < 0.05). Overall, 9/16 patients (56%) had MBL deficiency: 5/7 (71%) of patients with CMV disease, 4/4 (100%) of patients with asymptomatic CMVinfection, and 0/5 (0%) of patients withoutCMVinfection (p < 0.005, between CMV infection/disease versus no infection or control blood donors). There were no significant differences in age, gender or immunosuppressive regimens between the groups. MBL deficiency may be a significant risk factor for the development of post-prophylaxisCMVinfection in D+/R−kidney recipients, suggesting a new role of innate immunity in the control of CMV infection after organ transplantation.

Epithelial NAIPs protect against colonic tumorigenesis.

NLR family apoptosis inhibitory proteins (NAIPs) belong to both the Nod-like receptor (NLR) and the inhibitor of apoptosis (IAP) families. NAIPs are known to form an inflammasome with NLRC4, but other in vivo functions remain unexplored. Using mice deficient for all NAIP paralogs (Naip1-6(Δ/Δ)), we show that NAIPs are key regulators of colorectal tumorigenesis. Naip1-6(Δ/Δ) mice developed increased colorectal tumors, in an epithelial-intrinsic manner, in a model of colitis-associated cancer. Increased tumorigenesis, however, was not driven by an exacerbated inflammatory response. Instead, Naip1-6(Δ/Δ) mice were protected from severe colitis and displayed increased antiapoptotic and proliferation-related gene expression. Naip1-6(Δ/Δ) mice also displayed increased tumorigenesis in an inflammation-independent model of colorectal cancer. Moreover, Naip1-6(Δ/Δ) mice, but not Nlrc4-null mice, displayed hyper-activation of STAT3 and failed to activate p53 18 h after carcinogen exposure. This suggests that NAIPs protect against tumor initiation in the colon by promoting the removal of carcinogen-elicited epithelium, likely in a NLRC4 inflammasome-independent manner. Collectively, we demonstrate a novel epithelial-intrinsic function of NAIPs in protecting the colonic epithelium against tumorigenesis.