A decrease in the abundance and biodiversity of intestinal bacteria within the dominant phylum Firmicutes has been observed repeatedly in Crohn disease (CD) patients. In this study, we determined the composition of the mucosa-associated microbiota of CD patients at the time of surgical resection and 6 months later using FISH analysis. We found that a reduction of a major member of Firmicutes, Faecalibacterium prausnitzii, is associated with a higher risk of postoperative recurrence of ileal CD. A lower proportion of F. prausnitzii on resected ileal Crohn mucosa also was associated with endoscopic recurrence at 6 months. To evaluate the immunomodulatory properties of F. prausnitzii we analyzed the anti-inflammatory effects of F. prausnitzii in both in vitro (cellular models) and in vivo [2,4,6-trinitrobenzenesulphonic acid (TNBS)-induced] colitis in mice. In Caco-2 cells transfected with a reporter gene for NF-kappaB activity, F. prausnitzii had no effect on IL-1beta-induced NF-kappaB activity, whereas the supernatant abolished it. In vitro peripheral blood mononuclear cell stimulation by F. prausnitzii led to significantly lower IL-12 and IFN-gamma production levels and higher secretion of IL-10. Oral administration of either live F. prausnitzii or its supernatant markedly reduced the severity of TNBS colitis and tended to correct the dysbiosis associated with TNBS colitis, as demonstrated by real-time quantitative PCR (qPCR) analysis. F. prausnitzii exhibits anti-inflammatory effects on cellular and TNBS colitis models, partly due to secreted metabolites able to block NF-kappaB activation and IL-8 production. These results suggest that counterbalancing dysbiosis using F. prausnitzii as a probiotic is a promising strategy in CD treatment.

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Faecalibacterium prausnitzii is an anti-inflammatory commensal bacterium identified by gut microbiota analysis of Crohn disease patients

Background Infliximab, a chimeric monoclonal antibody directed against tumor necrosis factor α, is an established treatment for Crohn's disease but not ulcerative colitis. Methods Two randomized, double-blind, placebo-controlled studies — the Active Ulcerative Colitis Trials 1 and 2 (ACT 1 and ACT 2, respectively) — evaluated the efficacy of infliximab for induction and maintenance therapy in adults with ulcerative colitis. In each study, 364 patients with moderate-to-severe active ulcerative colitis despite treatment with concurrent medications received placebo or infliximab (5 mg or 10 mg per kilogram of body weight) intravenously at weeks 0, 2, and 6 and then every eight weeks through week 46 (in ACT 1) or week 22 (in ACT 2). Patients were followed for 54 weeks in ACT 1 and 30 weeks in ACT 2. Results In ACT 1, 69 percent of patients who received 5 mg of infliximab and 61 percent of those who received 10 mg had a clinical response at week 8, as compared with 37 percent of those who received placebo (P<0...

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Infliximab for induction and maintenance therapy for ulcerative colitis.

Clinical epidemiology of inflammatory bowel disease: incidence, prevalence, and environmental influences

The discovery of a series of genetic and serological markers associated with disease susceptibility and phenotype in inflammatory bowel disease has led to the prospect of an integrated classification system involving clinical, serological and genetic parameters. The Working Party has reviewed current clinical classification systems in Crohn's disease, ulcerative colitis and indeterminate colitis, and provided recommendations for clinical classification in practice. Progress with respect to integrating serological and genetic markers has been examined in detail, and the implications are discussed. While an integrated system is not proposed for clinical use at present, the introduction of a widely acceptable clinical subclassification is strongly advocated, which would allow detailed correlations among serotype, genotype and clinical phenotype to be examined and confirmed in independent cohorts of patients and, thereby, provide a vital foundation for future work.

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Toward an Integrated Clinical, Molecular and Serological Classification of Inflammatory Bowel Disease: Report of a Working Party of the 2005 Montreal World Congress of Gastroenterology

In this randomized, double-blind trial, we evaluated the efficacy of infliximab monotherapy, azathioprine monotherapy, and the two drugs combined in 508 adults with moderate-to-severe Crohn’s disease who had not undergone previous immunosuppressive or biologic therapy. Patients were randomly assigned to receive an intravenous infusion of 5 mg of infliximab per kilogram of body weight at weeks 0, 2, and 6 and then every 8 weeks plus daily oral placebo capsules; 2.5 mg of oral azathioprine per kilogram daily plus a placebo infusion on the standard schedule; or combination therapy with the two drugs. Patients received study medication through week 30 and could continue in a blinded study extension through week 50. Results Of the 169 patients receiving combination therapy, 96 (56.8%) were in corticosteroid-free clinical remission at week 26 (the primary end point), as compared with 75 of 169 patients (44.4%) receiving infliximab alone (P = 0.02) and 51 of 170 patients (30.0%) receiving azathioprine alone (P<0.001 for the comparison with combination therapy and P = 0.006 for the comparison with infliximab). Similar numerical trends were found at week 50. At week 26, mucosal healing had occurred in 47 of 107 patients (43.9%) receiving combination therapy, as compared with 28 of 93 patients (30.1%) receiving infliximab (P = 0.06) and 18 of 109 patients (16.5%) receiving azathioprine (P<0.001 for the comparison with combination therapy and P = 0.02 for the comparison with infliximab). Serious infections developed in 3.9% of patients in the combination-therapy group, 4.9% of those in the infliximab group, and 5.6% of those in the azathioprine group. Conclusions Patients with moderate-to-severe Crohn’s disease who were treated with infliximab plus azathioprine or infliximab monotherapy were more likely to have a corticosteroid-free clinical remission than those receiving azathioprine monotherapy. (ClinicalTrials.gov number, NCT00094458.)

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Infliximab, Azathioprine, or Combination Therapy for Crohn's Disease

Effect of colchicine on jejunal adenylate cyclase activity, PGE2 and cAMP contents

Twelve patients who underwent laparotomy for suspected acute appendicitis were found to have Crohn's disease of the terminal ileum. Appendectomy was performed in all although in only four patients was the appendix grossly inflamed. Postoperative complications, either abscess or fistula, developed in four patients (33%). Careful investigation of the records revealed some preoperative diagnostic clues: a history of recurrent abdominal pain and/or diarrhea (83%), physical examination revealing normal temperature (50%), and laboratory results compatible with a chronic process such as microcytic anemia (33%) and hypoproteinemia/hypoalbuminemia/hypocholesterolemia (50%). As the differential diagnosis between Crohn's disease and appendicitis is difficult and the surgical approach to the appendix in the presence of Crohn's disease is controversial, we illuminate some practical points in the preoperative evaluation of these patients and deal with the question of whether appendectomy should be performed in these patients.

Preoperative Clues to Crohn's Disease in Suspected, Acute Appendicitis. Report of 12 Cases and Review of the Literature

TNF alpha is a pro-inflammatory cytokine in Crohn's disease and it's neutralization is beneficial in patients with active disease. Remicade is a chimeric monoclonal anti-TNF antibody. Remicade is used in our center since December 1998 in 13 patients who were treated for active disease or fistula. We followed the patients and treatment results in order to estimate the efficacy and safety of this preparation. Response to treatment was measured by the Crohn's Disease Activity Index (CDAI) in patients treated due to active disease, or by the presence of discharge from external fistulae. Five out of seven patients with fistulae had less or no discharge after completing a course of 3 infusions. Four out of 6 patients treated due to active disease improved significantly after a single infusion. Five out of the six needed additional injections due to symptom recurrence. Intervals between infusions were 2 weeks--for fistulae patients to 32 weeks for patients with active disease. Adverse events for the 13 patients were usually mild except for 4 patients that suffered from anaphylactic shock, disseminated eruption (2) and eosinophilic pneumonitis. In summary, treatment of patients with active Crohn's disease or fistulae with monoclonal anti-TNF antibodies is an effective and relatively safe option after established treatment has failed. Analyzing the results of on going clinical trials and of the patients treated off-protocol will enable to establish new treatment strategies for patients with active Crohn's disease and fistulae.

[Treatment of Crohn's disease with anti TNF alpha antibodies--the experience in the Tel Aviv Medical Center].

Release of platelet-activating factor (PAF) by cultured colonic mucosa of patients with ulcerative colitis and healthy controls was determined. Before stimulation with calcium ionophore or antihuman IgE, no PAF release by control mucosa and minimal PAF release by mucosa of the colitis patients were detected. After stimulation with calcium ionophore, PAF release was four to five times higher by colonic mucosa of the colitis patients than of the controls. After stimulation with antihuman IgE, PAF release was twice as high by colonic mucosa of colitis patients as by control mucosa. Prednisolone, sulphasalazine, and mesalazine inhibited PAF activity stimulated by calcium ionophore in a dose-dependent manner. The results suggest that the use of PAF antagonists in the treatment of ulcerative colitis should be investigated.

Daniel Rachmilewitz

Papers

Effect of colchicine on jejunal adenylate cyclase activity, PGE2 and cAMP contents

Preoperative Clues to Crohn's Disease in Suspected, Acute Appendicitis. Report of 12 Cases and Review of the Literature

[Treatment of Crohn's disease with anti TNF alpha antibodies--the experience in the Tel Aviv Medical Center].

Platelet-activating factor--a possible mediator in the pathogenesis of ulcerative colitis.

Effect of opiates on human colonic adenylate cyclase activity.