André Van Gossum

Genome-wide association defines more than 30 distinct susceptibility loci for Crohn's disease

Several risk factors for Crohns disease have been identified in recent genome-wide association studies. To advance gene discovery further, we combined data from three studies on Crohns disease (a total of 3,230 cases and 4,829 controls) and carried out replication in 3,664 independent cases with a mixture of population-based and family-based controls. The results strongly confirm 11 previously reported loci and provide genome-wide significant evidence for 21 additional loci, including the regions containing STAT3, JAK2, ICOSLG, CDKAL1 and ITLN1. The expanded molecular understanding of the basis of this disease offers promise for informed therapeutic development.

Genome-wide meta-analysis increases to 71 the number of confirmed Crohn's disease susceptibility loci

We undertook a meta-analysis of six Crohns disease genome-wide association studies (GWAS) comprising 6,333 affected individuals (cases) and 15,056 controls and followed up the top association signals in 15,694 cases, 14,026 controls and 414 parent-offspring trios. We identified 30 new susceptibility loci meeting genome-wide significance (P < 5 × 10−8). A series of in silico analyses highlighted particular genes within these loci and, together with manual curation, implicated functionally interesting candidate genes including SMAD3, ERAP2, IL10, IL2RA, TYK2, FUT2, DNMT3A, DENND1B, BACH2 and TAGAP. Combined with previously confirmed loci, these results identify 71 distinct loci with genome-wide significant evidence for association with Crohns disease.

Novel Crohn disease locus identified by genome-wide association maps to a gene desert on 5p13.1 and modulates expression of PTGER4

To identify novel susceptibility loci for Crohn disease (CD), we undertook a genome-wide association study with more than 300,000 SNPs characterized in 547 patients and 928 controls. We found three chromosome regions that provided evidence of disease association with p-values between 10−6 and 10−9. Two of these (IL23R on Chromosome 1 and CARD15 on Chromosome 16) correspond to genes previously reported to be associated with CD. In addition, a 250-kb region of Chromosome 5p13.1 was found to contain multiple markers with strongly suggestive evidence of disease association (including four markers with p < 10−7). We replicated the results for 5p13.1 by studying 1,266 additional CD patients, 559 additional controls, and 428 trios. Significant evidence of association (p < 4 × 10−4) was found in case/control comparisons with the replication data, while associated alleles were over-transmitted to affected offspring (p < 0.05), thus confirming that the 5p13.1 locus contributes to CD susceptibility. The CD-associated 250-kb region was saturated with 111 SNP markers. Haplotype analysis supports a complex locus architecture with multiple variants contributing to disease susceptibility. The novel 5p13.1 CD locus is contained within a 1.25-Mb gene desert. We present evidence that disease-associated alleles correlate with quantitative expression levels of the prostaglandin receptor EP4, PTGER4, the gene that resides closest to the associated region. Our results identify a major new susceptibility locus for CD, and suggest that genetic variants associated with disease risk at this locus could modulate cis-acting regulatory elements of PTGER4.

Capsule endoscopy versus colonoscopy for the detection of polyps and cancer.

BACKGROUND An ingestible capsule consisting of an endoscope equipped with a video camera at both ends was designed to explore the colon. This study compared capsule endoscopy with optical colonoscopy for the detection of colorectal polyps and cancer. METHODS We performed a prospective, multicenter study comparing capsule endoscopy with optical colonoscopy (the standard for comparison) in a cohort of patients with known or suspected colonic disease for the detection of colorectal polyps or cancer. Patients underwent an adapted colon preparation, and colon cleanliness was graded from poor to excellent. We computed the sensitivity and specificity of capsule endoscopy for polyps, advanced adenoma, and cancer. RESULTS A total of 328 patients (mean age, 58.6 years) were included in the study. The capsule was excreted within 10 hours after ingestion and before the end of the lifetime of the battery in 92.8% of the patients. The sensitivity and specificity of capsule endoscopy for detecting polyps that were 6 mm in size or bigger were 64% (95% confidence interval [CI], 59 to 72) and 84% (95% CI, 81 to 87), respectively, and for detecting advanced adenoma, the sensitivity and specificity were 73% (95% CI, 61 to 83) and 79% (95% CI, 77 to 81), respectively. Of 19 cancers detected by colonoscopy, 14 were detected by capsule endoscopy (sensitivity, 74%; 95% CI, 52 to 88). For all lesions, the sensitivity of capsule endoscopy was higher in patients with good or excellent colon cleanliness than in those with fair or poor colon cleanliness. Mild-to-moderate adverse events were reported in 26 patients (7.9%) and were mostly related to the colon preparation. CONCLUSIONS The use of capsule endoscopy of the colon allows visualization of the colonic mucosa in most patients, but its sensitivity for detecting colonic lesions is low as compared with the use of optical colonoscopy. (ClinicalTrials.gov number, NCT00604162.)

Multicenter randomized-control led clinical trial of probiotics (Lactobacillus johnsonii, LA1) on early endoscopic recurrence of Crohn's disease after ileo-caecal resection

Background Seventy percent of Crohns disease (CD) patients exhibit anastomotic recurrence within 1 year after ileo‐caecal surgery. Recent clinical trials suggest the beneficial use of probiotics in the control of intestinal inflammation in pouchitis and ulcerative colitis. This study is a multicenter clinical trial evaluating the efficacy of an oral administration of the probiotic LA1 on early postoperative endoscopic recurrence of CD. Methods Seventy patients with CD were enrolled prior to elective ileo‐caecal resection and randomly assigned after surgery to daily treatment with either Lactobacillus johnsonii, LA1, Nestlé (1010 colony‐forming units, CFU) (group A, n = 34) or placebo (group B, n = 36) for 12 weeks. The primary objective was to assess the effect of LA1 on the endoscopic recurrence rate at 12 weeks. Stratification was performed according to smoking status at randomization. Results Seven and 14 patients were excluded in the LA1 and placebo groups, respectively. In intention‐to‐treat analysis, the mean endoscopic score was not significantly different between the two treatment groups at 3 months (LA1 versus placebo: 1.50 ± 1.32 versus 1.22 ± 1.37, treatment effect: P = 0.48, smoke effect: P = 0.72). The percentage of patients with severe recurrence (i3 + i4) was 21% and 15% in the LA1 and placebo groups, respectively (P = 0.33). Using a per‐protocol (PP) analysis, the mean endoscopic score was not significantly different between the two treatment groups (LA1 versus placebo groups: 1.44 ± 1.31 versus 1.05 ± 1.21, P = 0.32). The percentage of patients with severe recurrence (i3 + i4) was 19% and 9% in the LA1 and placebo groups, respectively (P = 0.054). Clinical relapse rate (CDAI [CD activity index] > 150, with an increase of CDAI > 70 points or greater from baseline) in the LA1 and placebo groups was 15% (4/27) and 13.5% (3/22), respectively (PP analysis: chi‐square test, P = 0.91 and log‐rank test: P = 0.79). Conclusion Oral administration of the probiotic LA1 in patients with CD failed to prevent early endoscopic recurrence at 12 weeks after ileo‐caecal resection. (Inflamm Bowel Dis 2007)

ESPEN Guidelines on Parenteral Nutrition: Home Parenteral Nutrition (HPN) in adult patients

Home parenteral nutrition (HPN) was introduced as a treatment modality in the early 1970s primarily for the treatment of chronic intestinal failure in patients with benign disease. The relatively low morbidity and mortality associated with HPN has encouraged its widespread use in western countries. Thus there is huge clinical experience, but there are still few controlled clinical studies of treatment effects and management of complications. The purpose of these guidelines is to highlight areas of good practice and promote the use of standardized treatment protocols between centers. The guidelines may serve as a framework for development of policies and procedures.

Second-generation colon capsule endoscopy compared with colonoscopy

BACKGROUND Colon capsule endoscopy (CCE) represents a noninvasive technology that allows visualization of the colon without requiring sedation and air insufflation. A second-generation colon capsule endoscopy system (PillCam Colon 2) (CCE-2) was developed to increase sensitivity for colorectal polyp detection compared with the first-generation system. OBJECTIVE To assess the feasibility, accuracy, and safety of CCE-2 in a head-to-head comparison with colonoscopy. DESIGN AND SETTING Prospective, multicenter trial including 8 European sites. PATIENTS This study involved 117 patients (mean age 60 years). Data from 109 patients were analyzed. INTERVENTION CCE-2 was prospectively compared with conventional colonoscopy as the criterion standard for the detection of colorectal polyps that are ≥6 mm or masses in a cohort of patients at average or increased risk of colorectal neoplasia. Colonoscopy was independently performed within 10 hours after capsule ingestion or on the next day. MAIN OUTCOME MEASUREMENTS CCE-2 sensitivity and specificity for detecting patients with polyps ≥6 mm and ≥10 mm were assessed. Capsule-positive but colonoscopy-negative cases were counted as false positive. Capsule excretion rate, level of bowel preparation, and rate of adverse events also were assessed. RESULTS Per-patient CCE-2 sensitivity for polyps ≥6 mm and ≥10 mm was 84% and 88%, with specificities of 64% and 95%, respectively. All 3 invasive carcinomas were detected by CCE-2. The capsule excretion rate was 88% within 10 hours. Overall colon cleanliness for CCE-2 was adequate in 81% of patients. LIMITATIONS Not unblinding the CCE-2 results at colonoscopy; heterogenous patient population; nonconsecutive patients. CONCLUSION In this European, multicenter study, CCE-2 appeared to have a high sensitivity for the detection of clinically relevant polypoid lesions, and it might be considered an adequate tool for colorectal imaging.

Long-term follow-up of patients on home parenteral nutrition in Europe: implications for intestinal transplantation

Background The indications for intestinal transplantation (ITx) are still debated. Knowing survival rates and causes of death on home parenteral nutrition (HPN) will improve decisions. Methods A prospective 5-year study compared 389 non-candidates (no indication, no contraindication) and 156 candidates (indication, no contraindication) for ITx. Indications were: HPN failure (liver failure; multiple episodes of catheter-related venous thrombosis or sepsis; severe dehydration), high-risk underlying disease (intra-abdominal desmoids; congenital mucosal disorders; ultra-short bowel), high morbidity intestinal failure. Causes of death were defined as: HPN-related, underlying disease, or other cause. Results The survival rate was 87% in non-candidates, 73% in candidates with HPN failure, 84% in those with high-risk underlying disease, 100% in those with high morbidity intestinal failure and 54%, in ITx recipients (one non-candidate and 21 candidates) (p<0.001). The primary cause of death on HPN was underlying disease-related in patients with HPN duration ≤2 years, and HPN-related in those on HPN duration >2 years (p=0.006). In candidates, the death HRs were increased in those with desmoids (7.1; 95% CI 2.5 to 20.5; p=0.003) or liver failure (3.4; 95% CI 1.6 to 7.3; p=0.002) compared to non-candidates. In deceased candidates, the indications for ITx were the causes of death in 92% of those with desmoids or liver failure, and in 38% of those with other indications (p=0.041). In candidates with catheter-related complications or ultra-short bowel, the survival rate was 83% in those who remained on HPN and 78% after ITx (p=0.767). Conclusions HPN is confirmed as the primary treatment for intestinal failure. Desmoids and HPN-related liver failure constitute indications for life-saving ITx. Catheter-related complications and ultra-short bowel might be indications for pre-emptive/rehabilitative ITx. In the early years after commencing HPN a life-saving ITx could be required for some patients at higher risk of death from their underlying disease.

ESPEN guidelines on chronic intestinal failure in adults

BACKGROUND & AIMS Chronic Intestinal Failure (CIF) is the long-lasting reduction of gut function, below the minimum necessary for the absorption of macronutrients and/or water and electrolytes, such that intravenous supplementation is required to maintain health and/or growth. CIF is the rarest organ failure. Home parenteral nutrition (HPN) is the primary treatment for CIF. No guidelines (GLs) have been developed that address the global management of CIF. These GLs have been devised to generate comprehensive recommendations for safe and effective management of adult patients with CIF. METHODS The GLs were developed by the Home Artificial Nutrition & Chronic Intestinal Failure Special Interest Group of ESPEN. The GRADE system was used for assigning strength of evidence. Recommendations were discussed, submitted to Delphi rounds, and accepted in an online survey of ESPEN members. RESULTS The following topics were addressed: management of HPN; parenteral nutrition formulation; intestinal rehabilitation, medical therapies, and non-transplant surgery, for short bowel syndrome, chronic intestinal pseudo-obstruction, and radiation enteritis; intestinal transplantation; prevention/treatment of CVC-related infection, CVC-related occlusion/thrombosis; intestinal failure-associated liver disease, gallbladder sludge and stones, renal failure and metabolic bone disease. Literature search provided 623 full papers. Only 12% were controlled studies or meta-analyses. A total of 112 recommendations are given: grade of evidence, very low for 51%, low for 39%, moderate for 8%, and high for 2%; strength of recommendation: strong for 63%, weak for 37%. CONCLUSIONS CIF management requires complex technologies, multidisciplinary and multiprofessional activity, and expertise to care for both the underlying gastrointestinal disease and to provide HPN support. The rarity of the condition impairs the development of RCTs. As a consequence, most of the recommendations have a low or very low grade of evidence. However, two-thirds of the recommendations are considered strong. Specialized management and organization underpin these recommendations.

Consecutive fecal calprotectin measurements to predict relapse in patients with ulcerative colitis receiving infliximab maintenance therapy

Background: This study examined whether fecal calprotectin can be used in daily practice as a marker to monitor patients with ulcerative colitis (UC) receiving infliximab maintenance therapy. Methods: This prospective multicenter study enrolled adult patients with UC in clinical remission under infliximab maintenance therapy. Fecal calprotectin levels were measured every 4 weeks. Sigmoidoscopies were performed at inclusion and at study end. Relapse was defined as a clinical need for change in treatment or an endoscopic Mayo subscore of ≥2 at week 52. Sustained deep remission was defined as a partial Mayo score <3 at all points and an endoscopic Mayo score 0 at week 52. Results: Full analysis was possible for 87 of 113 included patients with UC (77%). Of these patients, 30 (34.4%) were considered to be in sustained deep remission and 13 (14.9%) to have relapsed. Calprotectin levels in patients with sustained deep remission remained very low (median < 40 mg/kg at all time points). Patients who flared had significantly higher calprotectin levels (median > 300 mg/kg) already 3 months before the flare. Further receiver operator curve analysis suggested that a calprotectin level >300 mg/kg had a reasonable sensitivity (58.3%) and specificity (93.3%) to model flare. Two consecutive calprotectin measurements of >300 mg/kg with 1-month interval were identified as the best predictor of flare (61.5% sensitivity and 100% specificity). Conclusions: Fecal calprotectin can be used in daily practice to monitor patients with UC receiving infliximab maintenance therapy. Two consecutive measurements >300 mg/kg is more specific than a single measurement for predicting relapse.