Marc Ferrante

Long-term expansion of epithelial organoids from human colon, adenoma, adenocarcinoma, and Barrett's epithelium.

BACKGROUND & AIMS We previously established long-term culture conditions under which single crypts or stem cells derived from mouse small intestine expand over long periods. The expanding crypts undergo multiple crypt fission events, simultaneously generating villus-like epithelial domains that contain all differentiated types of cells. We have adapted the culture conditions to grow similar epithelial organoids from mouse colon and human small intestine and colon. METHODS Based on the mouse small intestinal culture system, we optimized the mouse and human colon culture systems. RESULTS Addition of Wnt3A to the combination of growth factors applied to mouse colon crypts allowed them to expand indefinitely. Addition of nicotinamide, along with a small molecule inhibitor of Alk and an inhibitor of p38, were required for long-term culture of human small intestine and colon tissues. The culture system also allowed growth of mouse Apc-deficient adenomas, human colorectal cancer cells, and human metaplastic epithelia from regions of Barretts esophagus. CONCLUSIONS We developed a technology that can be used to study infected, inflammatory, or neoplastic tissues from the human gastrointestinal tract. These tools might have applications in regenerative biology through ex vivo expansion of the intestinal epithelia. Studies of these cultures indicate that there is no inherent restriction in the replicative potential of adult stem cells (or a Hayflick limit) ex vivo.

Mucosal healing predicts long‐term outcome of maintenance therapy with infliximab in Crohn's disease

Background: Infliximab (IFX) treatment induces mucosal healing (MH) in patients with Crohns disease (CD) but the impact of MH on the long‐term outcome of IFX treatment in CD is still debated. Methods: We studied MH during long‐term treatment with IFX in 214 CD patients. A total of 183 patients (85.5%) responded to induction therapy and 31 patients (14.5%) were primary nonresponders. They underwent lower gastrointestinal (GI) endoscopy within a median of 0.7 months (interquartile range [IQR] 0.1–6.8) prior to first IFX and after a median of 6.7 months (IQR 1.4–24.6) after start of IFX and were further analyzed. The relationship between the outcome of IFX treatment long‐term and MH was studied. Results: MH was observed in 67.8% of the 183 initial responders (n = 124), with 83 patients having complete healing (45.4%) and 41 having partial healing (22.4%). Scheduled IFX treatment from the start resulted in MH more frequently (76.9% MH rate) than episodic treatment (61.0% MH rate; P = 0.0222, odds ratio [OR] 2.14, 95% confidence interval [CI] 1.11–4.12). Concomitant treatment with corticosteroids (CS) had a negative impact on MH (37.9% in patients with CS versus 63.2% in patients without CS; P = 0.021, OR 0.36, 95% CI 0.16–0.80). MH was associated with a significantly lower need for major abdominal surgery (MAS) during long‐term follow‐up (14.1% of patients with MH needed MAS versus 38.4% of patients without MH; P < 0.0001). Conclusions: MH induced by long‐term maintenance IFX treatment is associated with an improved long‐term outcome of the disease especially with a lower need for major abdominal surgeries. (Inflamm Bowel Dis 2009;)

Long-term outcome of treatment with infliximab in 614 patients with Crohn's disease: results from a single-centre cohort

Background and aims: This observational study assessed the long-term clinical benefit of infliximab (IFX) in 614 consecutive patients with Crohn’s disease (CD) from a single centre during a median follow-up of 55 months (interquartile range (IQR) 27–83). Methods: The primary analysis looked at the proportion of patients with initial response to IFX who had sustained clinical benefit at the end of follow-up. The long-term effects of IFX on the course of CD as reflected by the rate of surgery and hospitalisations and need for corticosteroids were also analysed. Results: 10.9% of patients were primary non-responders to IFX. Sustained benefit was observed in 347 of the 547 patients (63.4%) receiving long-term treatment. In 68.3% of these, treatment with IFX was ongoing and in 31.7% IFX was stopped, with the patient being in remission. Seventy patients (12.8%) had to stop IFX due to side effects and 118 (21.6%) due to loss of response. Although the yearly drop-out rates of IFX in patients with episodic (10.7%) and scheduled treatment (7.1%) were similar, the need for hospitalisations and surgery decreased less in the episodic than in the scheduled group. Steroid discontinuation also occurred in a higher proportion of patients in the scheduled group than in the episodic group. Conclusions: In this large real-life cohort of patients with CD, long-term treatment with IFX was very efficacious to maintain improvement during a median follow-up of almost 5 years and changed disease outcome by decreasing the rate of hospitalisations and surgery.

A decrease of the butyrate-producing species Roseburia hominis and Faecalibacterium prausnitzii defines dysbiosis in patients with ulcerative colitis

Objective Bacteria play an important role in the onset and perpetuation of intestinal inflammation in inflammatory bowel disease (IBD). Unlike in Crohns disease (CD), in which dysbiosis has been better characterised, in ulcerative colitis (UC), only small cohorts have been studied and showed conflicting data. Therefore, we evaluated in a large cohort if the microbial signature described in CD is also present in UC, and if we could characterise predominant dysbiosis in UC. To assess the functional impact of dysbiosis, we quantified the bacterial metabolites. Design The predominant microbiota from 127 UC patients and 87 age and sex-matched controls was analysed using denaturing gradient gel electrophoresis (DGGE) analysis. Differences were quantitatively validated using real-time PCR. Metabolites were quantified using gas chromatography–mass spectrometry. Results Based on DGGE analysis, the microbial signature previously described in CD was not present in UC. Real-time PCR analysis revealed a lower abundance of Roseburia hominis (p<0.0001) and Faecalibacterium prausnitzii (p<0.0001) in UC patients compared to controls. Both species showed an inverse correlation with disease activity. Short-chain fatty acids (SCFA) were reduced in UC patients (p=0.014), but no direct correlation between SCFA and the identified bacteria was found. Conclusions The composition of the fecal microbiota of UC patients differs from that of healthy individuals: we found a reduction in R hominis and F prausnitzii, both well-known butyrate-producing bacteria of the Firmicutes phylum. These results underscore the importance of dysbiosis in IBD but suggest that different bacterial species contribute to the pathogenesis of UC and CD.

Influence of Trough Serum Levels and Immunogenicity on Long-term Outcome of Adalimumab Therapy in Crohn's Disease

BACKGROUND & AIMS Adalimumab is an efficacious therapy for active Crohns disease, but long-term data are scarce. We conducted an observational study to assess the long-term clinical benefit of adalimumab in patients who failed to respond to infliximab, specifically focusing on the influence of trough serum concentration and antibodies against adalimumab on clinical outcome. METHODS A total of 168 patients with Crohns disease treated with adalimumab in a tertiary center were included in a prospective follow-up program. Trough serum concentration and antibodies against adalimumab were measured at predefined time points using enzyme-linked immunosorbent assays. RESULTS A total of 71% and 67% of patients responded by weeks 4 and 12, respectively; among them, 61.5% demonstrated sustained clinical benefit until the end of follow-up (median [interquartile range], 20.4 [11.7-30.0] months). Of the 156 patients receiving maintenance therapy, 102 (65.4%) had to step up to 40 mg weekly and 60 (38.5%) eventually stopped adalimumab therapy mainly due to loss of response. Significantly lower adalimumab trough serum concentrations were measured throughout the follow-up period in patients who discontinued therapy as compared with patients who stayed on adalimumab. Antibodies against adalimumab were present in 9.2% of the patients and affected trough serum concentration. Serious adverse events occurred in 12% of the patients. CONCLUSIONS Introduction of adalimumab after failure of infliximab therapy resulted in a sustained clinical benefit in two thirds of patients during a median follow-up period of almost 2 years. Discontinuation was directly related to low adalimumab trough serum concentration, which was observed more frequently in patients who developed antibodies against adalimumab.

Fecal calprotectin is a surrogate marker for endoscopic lesions in inflammatory bowel disease

Background: Fecal calprotectin is a marker of inflammation in inflammatory bowel disease (IBD). Since mucosal healing has become a goal of treatment in IBD we examined how reliably calprotectin levels reflect mucosal disease activity. Methods: In all, 126 IBD patients and 32 irritable bowel syndrome (IBS) patients needing colonoscopy delivered a sample of feces prior to the start of bowel cleansing. Besides collection of symptom scores and blood tests, experienced endoscopists recorded the Simple Endoscopic Score for Crohns Disease (SES‐CD) and the Crohns Disease Endoscopic Index of Severity (CDEIS) in Crohns disease (CD) patients and the Mayo endoscopic score in ulcerative colitis (UC) patients. Stool samples were shipped for central calprotectin PhiCal Assay (enzyme‐linked immunosorbent assay [ELISA]). Correlation analysis was done with Pearson statistics. Results: The median (interquartile range [IQR]) fecal calprotectin levels were 175 (44–938) &mgr;g/g in CD, 465 (61–1128) &mgr;g/g in UC, and 54 (16–139) &mgr;g/g in IBS. Correlations were significant with endoscopic disease scores in both CD and in UC. Using ROC statistics, a cutoff value of 250 &mgr;g/g indicated the presence of large ulcers with a sensitivity of 60.4% and a specificity of 79.5% (positive predictive value [PPV] 78.4%, negative predictive value [NPV] 62.0%) in CD. Levels ≤250 &mgr;g/g predicted endoscopic remission (CDEIS ≤3) with 94.1% sensitivity and 62.2% specificity (PPV 48.5%, NPV 96.6%). In UC, a fecal calprotectin >250 &mgr;g/g gave a sensitivity of 71.0% and a specificity of 100.0% (PPV 100.0%, NPV 47.1%) for active mucosal disease activity (Mayo >0). Calprotectin levels significantly correlated with symptom scores in UC (r = 0.561, P < 0.001), but not in CD. Conclusions: Fecal calprotectin levels correlate significantly with endoscopic disease activity in IBD. The test appears useful in clinical practice for assessment of endoscopic activity and remission. (Inflamm Bowel Dis 2012;)

European evidence based consensus for endoscopy in inflammatory bowel disease

Endoscopy plays an essential role in the diagnosis, management, prognosis, and surveillance of inflammatory bowel disease (IBD), but surprisingly there are few available guidelines.1,2 This prompted the ECCO Guidelines Committee (GuiCom) members to promote a Consensus on the appropriate indication and application of different endoscopic modalities in IBD. Since the development of guidelines is an expensive and time-consuming process, this Consensus may help to avoid duplication of effort in the future. It may also identify issues where the evidence is lacking and controlled studies are awaited. The strategy to reach the Consensus involved five steps: 1. Two members of the GuiCom (VA and RE) identified four main topics: a) Diagnosis and follow-up; b) Score of endoscopic activity; c) Small bowel endoscopy; and d) Surveillance. During 2012 a call for participants to the Guideline was made to ECCO members. In addition, expert endoscopists recognised for their active research in the field were invited. Participants were selected by the Guicom and four working groups were created. Each working group had a chair (VA, MD, MT, and RE), two ECCO members including young members (Y-ECCO) and one experienced endoscopist. For the development of the guideline, relevant questions on separate topics were devised by the chairmen and their working parties. The questions were focused on current practice and areas of controversy. Participants of the Consensus process were asked to answer the questions based on evidence from the literature as well as their experience (Delphi procedure)3; 2. The working parties working in parallel performed a systematic literature search of their topic with the appropriate key words using Medline/Pubmed and the Cochrane database, as well as other relevant sources; 3. Provisional guideline statements on their topic were then written by the chairmen. These were circulated and commented on first by working party members and …

New serological markers in inflammatory bowel disease are associated with complicated disease behaviour

Background and aims: Several antibodies have been associated with Crohn’s disease and are associated with distinct clinical phenotypes. The aim of this study was to determine whether a panel of new antibodies against bacterial peptides and glycans could help in differentiating inflammatory bowel disease (IBD), and whether they were associated with particular clinical manifestations. Methods: Antibodies against a mannan epitope of Saccharomyces cerevisiae (gASCA), laminaribioside (ALCA), chitobioside (ACCA), mannobioside (AMCA), outer membrane porins (Omp) and the atypical perinuclear antineutrophilic cytoplasmic antibody (pANCA) were tested in serum samples of 1225 IBD patients, 200 healthy controls and 113 patients with non-IBD gastrointestinal inflammation. Antibody responses were correlated with the type of disease and clinical characteristics. Results: 76% of Crohn’s disease patients had at least one of the tested antibodies. For differentiation between Crohn’s disease and ulcerative colitis, the combination of gASCA and pANCA was most accurate. For differentiation between IBD, healthy controls and non-IBD gastrointestinal inflammation, the combination of gASCA, pANCA and ALCA had the best accuracy. Increasing amounts and levels of antibody responses against gASCA, ALCA, ACCA, AMCA and Omp were associated with more complicated disease behaviour (44.7% versus 53.6% versus 71.1% versus 82.0%, p < 0.001), and a higher frequency of Crohn’s disease-related abdominal surgery (38.5% versus 48.8% versus 60.7% versus 75.4%, p < 0.001). Conclusions: Using this new panel of serological markers, the number and magnitude of immune responses to different microbial antigens were shown to be associated with the severity of the disease. With regard to the predictive role of serological markers, further prospective longitudinal studies are necessary.

Mucosal gene signatures to predict response to infliximab in patients with ulcerative colitis

Background and aims: Infliximab is an effective treatment for ulcerative colitis with over 60% of patients responding to treatment and up to 30% reaching remission. The mechanism of resistance to anti-tumour necrosis factor α (anti-TNFα) is unknown. This study used colonic mucosal gene expression to provide a predictive response signature for infliximab treatment in ulcerative colitis. Methods: Two cohorts of patients who received their first treatment with infliximab for refractory ulcerative colitis were studied. Response to infliximab was defined as endoscopic and histological healing. Total RNA from pre-treatment colonic mucosal biopsies was analysed with Affymetrix Human Genome U133 Plus 2.0 Arrays. Quantitative RT-PCR was used to confirm microarray data. Results: For predicting response to infliximab treatment, pre-treatment colonic mucosal expression profiles were compared for responders and non-responders. Comparative analysis identified 179 differentially expressed probe sets in cohort A and 361 in cohort B with an overlap of 74 probe sets, representing 53 known genes, between both analyses. Comparative analysis of both cohorts combined, yielded 212 differentially expressed probe sets. The top five differentially expressed genes in a combined analysis of both cohorts were osteoprotegerin, stanniocalcin-1, prostaglandin-endoperoxide synthase 2, interleukin 13 receptor alpha 2 and interleukin 11. All proteins encoded by these genes are involved in the adaptive immune response. These markers separated responders from non-responders with 95% sensitivity and 85% specificity. Conclusion: Gene array studies of ulcerative colitis mucosal biopsies identified predictive panels of genes for (non-)response to infliximab. Further study of the pathways involved should allow a better understanding of the mechanisms of resistance to infliximab therapy in ulcerative colitis. ClinicalTrials.gov number, NCT00639821.

Results from the 2nd Scientific Workshop of the ECCO (I): Impact of mucosal healing on the course of inflammatory bowel disease

Over the past years, mucosal healing has emerged as a major therapeutic goal in clinical trials in inflammatory bowel diseases. Accumulating evidence indicates that mucosal healing may change the natural course of the disease by decreasing the need for surgery and reducing hospitalization rates in both ulcerative colitis and Crohns disease. Mucosal healing may also prevent the development of long-term disease complications, such as bowel damage in Crohns disease and colorectal cancer in ulcerative colitis. Histologic healing may be the ultimate therapeutic goal in ulcerative colitis, whereas its impact on the course of Crohns disease is unknown. Complete mucosal healing may be required before considering drug withdrawal. Targeting early Crohns disease is more effective than approaches aimed at healing mucosa in longstanding disease. Several questions remain to be answered: should mucosal healing be systematically used in clinical practice? Should we optimize therapies to achieve mucosal healing? What is the degree of intestinal healing that is required to change the disease course? Large prospective studies addressing these issues are needed.