Gut Microbiome Composition Is Associated With Future Onset of Crohn's Disease in Healthy First-Degree Relatives.

BACKGROUND & AIMS: The cause of Crohn's disease (CD) is unknown, but the current hypothesis is that microbial or environmental factors induce gut inflammation in genetically susceptible individuals, leading to chronic intestinal inflammation. Case-control studies of patients with CD have cataloged alterations in the gut microbiome composition; however, these studies fail to distinguish whether the altered gut microbiome composition is associated with initiation of CD or is the result of inflammation or drug treatment. METHODS: In this prospective cohort study, 3483 healthy first-degree relatives (FDRs) of patients with CD were recruited to identify the gut microbiome composition that precedes the onset of CD and to what extent this composition predicts the risk of developing CD. We applied a machine learning approach to the analysis of the gut microbiome composition (based on 16S ribosomal RNA sequencing) to define a microbial signature that associates with future development of CD. The performance of the model was assessed in an independent validation cohort. RESULTS: In the validation cohort, the microbiome risk score (MRS) model yielded a hazard ratio of 2.24 (95% confidence interval, 1.03-4.84; P = .04), using the median of the MRS from the discovery cohort as the threshold. The MRS demonstrated a temporal validity by capturing individuals that developed CD up to 5 years before disease onset (area under the curve > 0.65). The 5 most important taxa contributing to the MRS included Ruminococcus torques, Blautia, Colidextribacter, an uncultured genus-level group from Oscillospiraceae, and Roseburia. CONCLUSION: This study is the first to demonstrate that gut microbiome composition is associated with future onset of CD and suggests that gut microbiome is a contributor in the pathogenesis of CD.

Environmental Factors Associated with Risk of Crohn's Disease Development in the Crohn's and Colitis Canada - Genetic, Environmental, Microbial Project.

BACKGROUND & AIMS: To date, it is unclear how environmental factors influence Crohn's disease (CD) risk and how they interact with biological processes. This study investigates the association between environmental exposures and CD risk and evaluates their association with pre-disease biomarkers. METHODS: We studied 4289 healthy first-degree relatives (FDRs) of patients with CD from the Crohn's and Colitis Canada - Genetic, Environmental, Microbial (CCC-GEM) project. Regression models identified environmental factors associated with future CD onset and their association with pre-disease biological factors, including altered intestinal permeability measured by urinary fractional excretion of lactulose to mannitol ratio (LMR); gut inflammation via fecal calprotectin (FCP) levels; and fecal microbiome composition through 16S rRNA sequencing. RESULTS: Over a 5.62-year median follow-up, 86 FDRs developed CD. Living with a dog between ages 5 and 15 (hazard ratio [HR], 0.62; 95% confidence interval [CI], 0.40-0.96; P = .034), and living with a large family size in the first year of life (HR, 0.43; 95% CI, 0.21-0.85; P = .016) were associated with decreased CD risk, whereas having a bird at the time of recruitment (HR, 2.78; 95% CI, 1.36-5.68; P = .005) was associated with an increased CD risk. Furthermore, living with a dog was associated with reduced LMR, altered relative abundance of multiple bacterial genera, and increased Chao1 diversity, whereas bird owners had higher FCP levels. Large family during participants' first year of life was associated with altered microbiota composition without affecting FCP or LMR. CONCLUSION: This study identifies environmental variables associated with CD risk. These variables were also associated with altered barrier function, subclinical inflammation, and gut microbiome composition shifts, suggesting potential roles in CD pathogenesis.

Immune response and barrier dysfunction-related proteomic signatures in preclinical phase of Crohn's disease highlight earliest events of pathogenesis.

OBJECTIVE: The measure of serum proteome in the preclinical state of Crohn's disease (CD) may provide insight into biological pathways involved in CD pathogenesis. We aimed to assess associations of serum proteins with future CD onset and with other biomarkers predicting CD risk in a healthy at-risk cohort. DESIGN: In a nested case-control study within the Crohn's and Colitis Canada Genetics Environment Microbial Project (CCC-GEM) cohort, which prospectively follows healthy first-degree relatives (FDRs), subjects who developed CD (n=71) were matched with four FDRs remaining healthy (n=284). Using samples at recruitment, serum protein profiles using the Olink Proximity Extension Assay platform was assessed for association with future development of CD and with other baseline biomarkers as follows: serum antimicrobial antibodies (AS: positive antibody sum) (Prometheus); faecal calprotectin (FCP); gut barrier function using the fractional excretion of lactulose-to-mannitol ratio (LMR) assay. RESULTS: We identified 25 of 446 serum proteins significantly associated with future development of CD. C-X-C motif chemokine 9 (CXCL9) had the highest OR with future risk of CD (OR=2.07 per SD, 95% CI 1.58 to 2.73, q=7.9e-5), whereas matrix extracellular phosphoglycoprotein had the lowest OR (OR 0.44, 95% CI 0.29 to 0.66, q=0.02). Notably, CXCL9 was the only analyte significantly associated with all other CD-risk biomarkers with consistent direction of effect (FCP: OR=2.21; LMR: OR=1.67; AS: OR=1.59) (q<0.05 for all). CONCLUSION: We identified serum proteomic signatures associated with future CD development, reflecting potential early biological processes of immune and barrier dysfunction.

Mediterranean-Like Dietary Pattern Associations With Gut Microbiome Composition and Subclinical Gastrointestinal Inflammation.

BACKGROUND & AIMS: Case-control studies have shown that patients with Crohn's disease (CD) have a microbial composition different from healthy individuals. Although the causes of CD are unknown, epidemiologic studies suggest that diet is an important contributor to CD risk, potentially via modulation of bacterial composition and gut inflammation. We hypothesized that long-term dietary clusters (DCs) are associated with gut microbiome compositions and gut inflammation. Our objectives were to identify dietary patterns and assess whether they are associated with alterations in specific gut microbial compositions and subclinical levels of gut inflammation in a cohort of healthy first-degree relatives (FDRs) of patients with CD. METHODS: As part of the Genetic, Environmental, Microbial (GEM) Project, we recruited a cohort of 2289 healthy FDRs of patients with CD. Individuals provided stool samples and answered a validated food frequency questionnaire reflecting their habitual diet during the year before sample collection. Unsupervised analysis identified 3 dietary and 3 microbial composition clusters. RESULTS: DC3, resembling the Mediterranean diet, was strongly associated with a defined microbial composition, with an increased abundance of fiber-degrading bacteria, such as Ruminococcus, as well as taxa such as Faecalibacterium. The DC3 diet was also significantly associated with lower levels of subclinical gut inflammation, defined by fecal calprotectin, compared with other dietary patterns. No significant associations were found between individual food items and fecal calprotectin, suggesting that long-term dietary patterns rather than individual food items contribute to subclinical gut inflammation. Additionally, mediation analysis demonstrated that DC3 had a direct effect on subclinical inflammation that was partially mediated by the microbiota. CONCLUSIONS: Overall, these results indicated that Mediterranean-like dietary patterns are associated with microbiome and lower intestinal inflammation. This study will help guide future dietary strategies that affect microbial composition and host gut inflammation to prevent diseases.

Altered Gut Microbiome Composition and Function Are Associated With Gut Barrier Dysfunction in Healthy Relatives of Patients With Crohn's Disease.

BACKGROUND & AIMS: The gut microbiome has been suggested to play a role in gut barrier hemostasis, but data are scarce and limited to animal studies. We therefore aimed to assess whether alterations in gut microbial composition and functional pathways are associated with gut barrier function in a cohort of healthy first-degree relatives of patients with Crohn's disease. METHODS: We used the Crohn's and Colitis Canada Genetic Environmental Microbial (CCC-GEM) cohort of healthy first-degree relatives of patients with Crohn's disease. Gut barrier function was assessed using the urinary fractional excretion of lactulose-to-mannitol ratio (LMR). Microbiome composition was assessed by sequencing fecal 16S ribosomal RNA. The cohort was divided into a discovery cohort (n = 2472) and a validation cohort (n = 655). A regression model was used to assess microbial associations with the LMR. A random forest classifier algorithm was performed to assess microbial community contribution to barrier function. RESULTS: Individuals with impaired barrier function (LMR >0.025) had reduced alpha-diversity (Chao1 index, P = 4.0e-4) and altered beta-diversity (Bray-Curtis dissimilarity index, R2 = 0.001, P = 1.0e-3) compared with individuals with an LMR ≤0.025. When taxa were assessed individually, we identified 8 genera and 52 microbial pathways associated with an LMR >0.025 (q < 0.05). Four genera (decreased prevalence of Adlercreutzia, Clostridia UCG 014, and Clostridium sensu stricto 1 and increased abundance of Colidextribacter) and 8 pathways (including decreased biosynthesis of glutamate, tryptophan, and threonine) were replicated in the validation cohort. The random forest approach revealed that the bacterial community is associated with gut barrier function (area under the curve, 0.63; P = 1.4e-6). CONCLUSIONS: The gut microbiome community and pathways are associated with changes in gut barrier function. These findings may identify potential microbial targets to modulate gut barrier.

CORE-IBD: A Multidisciplinary International Consensus Initiative to Develop a Core Outcome Set for Randomized Controlled Trials in Inflammatory Bowel Disease.

BACKGROUND & AIMS: End points to determine the efficacy and safety of medical therapies for Crohn's disease (CD) and ulcerative colitis (UC) are evolving. Given the heterogeneity in current outcome measures, harmonizing end points in a core outcome set for randomized controlled trials is a priority for drug development in inflammatory bowel disease. METHODS: Candidate outcome domains and outcome measures were generated from systematic literature reviews and patient engagement surveys and interviews. An iterative Delphi process was conducted to establish consensus: panelists anonymously voted on items using a 9-point Likert scale, and feedback was incorporated between rounds to refine statements. Consensus meetings were held to ratify the outcome domains and core outcome measures. Stakeholders were recruited internationally, and included gastroenterologists, colorectal surgeons, methodologists, and clinical trialists. RESULTS: A total of 235 patients and 53 experts participated. Patient-reported outcomes, quality of life, endoscopy, biomarkers, and safety were considered core domains; histopathology was an additional domain for UC. In CD, there was consensus to use the 2-item patient-reported outcome (ie, abdominal pain and stool frequency), Crohn's Disease Activity Index, Simple Endoscopic Score for Crohn's Disease, C-reactive protein, fecal calprotectin, and co-primary end points of symptomatic remission and endoscopic response. In UC, there was consensus to use the 9-point Mayo Clinic Score, fecal urgency, Robarts Histopathology Index or Geboes Score, fecal calprotectin, and a composite primary end point including both symptomatic and endoscopic remission. Safety outcomes should be reported using the Medical Dictionary for Regulatory Activities. CONCLUSIONS: This multidisciplinary collaboration involving patients and clinical experts has produced the first core outcome set that can be applied to randomized controlled trials of CD and UC.

Anti-Microbial Antibody Response is Associated With Future Onset of Crohn's Disease Independent of Biomarkers of Altered Gut Barrier Function, Subclinical Inflammation, and Genetic Risk.

BACKGROUND AND AIMS: Altered host immune reactivity to microbial antigens is hypothesized to trigger the onset of Crohn's disease (CD). We aimed to assess whether increased serum anti-microbial antibody response in asymptomatic first-degree relatives (FDRs) of CD patients is an independent risk factor for future CD development. METHODS: We measured host serum antibody response to 6 microbial antigens at enrollment (Prometheus enzyme-linked immunosorbent assay test: anti-Saccharomyces cerevisiae antibodies immunoglobulin A/immunoglobulin G, anti-OmpC, anti-A4-Fla2, anti-FlaX, anti-CBir1) and derived the sum of positive antibodies (AS). We used samples at enrollment of prospectively followed healthy FDRs from a nested case-control cohort of the Crohn's and Colitis Canada Genetics Environment Microbial Project. Those who later developed CD (n = 77) were matched 1:4 by age, sex, follow-up duration, and geographic location with control FDRs remaining healthy (n = 307). To address our research aims, we fitted a multivariable conditional logistic regression model and performed causal mediation analysis. RESULTS: High baseline AS (≥2) (43% of cases, 11% of controls) was associated with higher risk of developing CD (adjusted odds ratio, 6.5; 95% confidence interval, 3.4-12.7; P < .001). Importantly, this association remained significant when adjusted for markers of gut barrier function, fecal calprotectin, C-reactive protein, and CD-polygenic risk score, and in subjects recruited more than 3 years before diagnosis. Causal mediation analysis showed that the effect of high AS on future CD development is partially mediated (42%) via preclinical gut inflammation. CONCLUSIONS: Our results suggest that increased anti-microbial antibody responses are associated with risk of future development of CD, independent of biomarkers of abnormal gut barrier function, subclinical inflammation, and CD-related genetic risks. This suggests that anti-microbial antibody responses are an early predisease event in the development of CD.

An International Multicenter Comparison of IBD-Related Disability and Validation of the IBDDI.

BACKGROUND: The IBD disability index (IBDDI) has been shown to be valid and reliable. We compared the distributional and predictive properties of the IBDDI, when collected from five populations of people living with IBD- from Winnipeg, Chicago, Toronto, Hong Kong, and Jerusalem. METHODS: People with IBD from five jurisdictions were invited to complete a survey including the IBDDI, the World Health Organization Disability Assessment Scale, the Work and Social Adjustment Scale, the IBDQ, the Kessler-6 distress scale, and the Stanford presenteeism scale. Between sites, we compared the correlation between IBDDI and the other 4 measures of disability/quality of life/distress, and the association between IBDDI and presenteeism and having been hospitalized in the past year. RESULTS: There were 1121 participants from Winnipeg, 511 from Chicago, 147 from Toronto, 97 from Hong Kong, and 96 from Jerusalem. The majority had Crohn's disease. Although the mean IBDDI score varied by site, the correlation between IBDDI and each of the other 4 measures of disability/QOL/distress was nearly identical. Similarly, the regression coefficient showing the association between IBDDI and presenteeism was nearly identical in all sites, and the risk ratios showing the association between hospitalization and high IBDDI was similar in all sites. CONCLUSION: The correlation between IBDDI and different measures of disability/QOL/distress was similar across all sites. There is strong evidence of the association between IBD-related disability and presenteeism, and between hospitalization and high IBD-related disability, and that the associations are the same across different populations. The severity of disability that an individual with a given IBDDI score has is directly comparable across populations.

Persistent Diarrhea in Patients With Crohn's Disease After Mucosal Healing Is Associated With Lower Diversity of the Intestinal Microbiome and Increased Dysbiosis.

BACKGROUND & AIMS: In patients with inflammatory bowel diseases (IBDs), symptoms do not always associate with the severity of endoscopic inflammation and can persist after mucosal healing. We investigated whether symptoms in patients with successfully treated IBD are related to the composition of the intestinal microbiome. METHODS: We analyzed 590 tissue biopsy specimens from 215 patients with IBD and 48 healthy individuals (controls). We obtained mucosal biopsy specimens from 2 colon sites (ascending and rectosigmoid) and from the terminal ileum along with clinical data. Bacterial DNA was extracted from the biopsy specimens and the V4 region of 16s ribosomal RNA sequenced by Miseq and processed using the QIIME v1.9 pipeline. RESULTS: Mucosal biopsy specimens from patients with Crohn's disease (CD) who achieved mucosal healing (Mayo scores of 0-1 or segmental endoscopic severity CD scores of 0-5) had lower Chao1 diversity than biopsy specimens from patients with ulcerative colitis (UC) or unclassified IBD (IBD-U), or controls. After endoscopic evidence of improvement in patients with UC or IBD-U, diversity of the tissue-associated microbiota did not differ significantly from that of controls. Colon biopsy specimens from patients with CD had lower microbial diversity, before and after healing (segmental endoscopic severity CD scores, 0-2), than colon biopsy specimens from controls (P < .002). In patients with CD who achieved mucosal healing, residual clinical activity (CD activity index scores >150; P = .03) and persistent diarrhea were associated with reduced microbial diversity (P = .01). Continued diarrhea was associated with a trend toward dysbiosis, based on the microbial dysbiosis index (P = .059). In patients with UC or IBD-U with moderate to severe inflammation, increasing severity of diarrhea was associated with reduced microbial diversity (P = .03). CONCLUSIONS: In an analysis of biopsy specimens from patients with IBD and controls, we found that despite endoscopic evidence of improvement or remission, α-diversity of the tissue-associated intestinal microbiome remained lower in patients with CD than in controls. This observation, along with the reduced Chao1 diversity and greater dysbiosis in intestinal microbiota of patients with residual symptoms of IBD, indicates that microbiome composition could be associated with persistent diarrhea.

Increased Intestinal Permeability Is Associated With Later Development of Crohn's Disease.

BACKGROUND & AIMS: Increased intestinal permeability has been associated with Crohn's disease (CD), but it is not clear whether it is a cause or result of the disease. We performed a prospective study to determine whether increased intestinal permeability is associated with future development of CD. METHODS: We assessed the intestinal permeability, measured by the urinary fractional excretion of lactulose-to-mannitol ratio (LMR) at recruitment in 1420 asymptomatic first-degree relatives (6-35 years old) of patients with CD (collected from 2008 through 2015). Participants were then followed up for a diagnosis of CD from 2008 to 2017, with a median follow-up time of 7.8 years. We analyzed data from 50 participants who developed CD after a median of 2.7 years during the study period, along with 1370 individuals who remained asymptomatic until October 2017. We used the Cox proportional hazards model to evaluate time-related risk of CD based on the baseline LMR. RESULTS: An abnormal LMR (>0.03) was associated with a diagnosis of CD during the follow-up period (hazard ratio, 3.03; 95% CI, 1.64-5.63; P = 3.97 × 10-4). This association remained significant even when the test was performed more than 3 years before the diagnosis of CD (hazard ratio, 1.62; 95% CI, 1.051-2.50; P = .029). CONCLUSIONS: Increased intestinal permeability is associated with later development of CD; these findings support a model in which altered intestinal barrier function contributes to pathogenesis. Abnormal gut barrier function might serve as a biomarker for risk of CD onset.

Comparative effectiveness of higher adalimumab maintenance therapy versus standard dose in anti-tumor necrosis factor experienced Crohn's disease patients: A propensity-score matched cohort analysis.

BACKGROUND AND AIM: Crohn's disease (CD) patients who previously failed anti-tumor necrosis factor (TNF) therapy are at higher risk of treatment failure with subsequent biologics. This study aims to determine the effectiveness and safety of higher maintenance dose regimens of adalimumab compared with standard doses in CD patients who failed anti-TNF. METHODS: In this retrospective observational study, CD patients who failed anti-TNF and received adalimumab were categorized according to their post-induction maintenance regimen; 40 mg subcutaneous (sc) weekly or 80 mg sc every other week were defined as a high-dose (HD) maintenance regimen, and 40 mg sc every other week was defined as a standard-dose (SD) maintenance regimen. The primary outcome was time to treatment failure. Cox proportional hazards regression was used to adjust for confounders. Sensitivity analysis was conducted using propensity scores to create a cohort of matched participants with similar distribution of baseline covariates. RESULTS: Forty patients started on HD regimens following induction, and 77 patients received the SD regimen. The median time to failure in the HD group was 6.6 years (interquartile range [IQR] 4.0-9.6) and 3.0 years (IQR 0.9-9.4) in the SD group (log-rank test P = 0.006). Patients on HD adalimumab had a lower hazard rate of treatment failure (hazard ratio: 0.27; 95% confidence interval [0.12, 0.62]; P = 0.002) compared with SD patients. No difference in adverse events was identified between groups (30% vs 31.2%, P = 1.0). Results were similar in the propensity score-matched cohort. CONCLUSIONS: High-dose maintenance regimens were associated with longer time-to-failure as compared with SD regimens in CD patient who failed anti-TNF.

Canadian Association of Gastroenterology Clinical Practice Guideline for the Management of Luminal Crohn's Disease.

BACKGROUND & AIMS: Crohn's disease (CD) is a lifelong illness with substantial morbidity, although new therapies and treatment paradigms have been developed. We provide guidance for treatment of ambulatory patients with mild to severe active luminal CD. METHODS: We performed a systematic review to identify published studies of the management of CD. The quality of evidence and strength of recommendations were rated according to the Grading of Recommendation Assessment, Development and Evaluation (GRADE) approach. Statements were developed through an iterative online platform and then finalized and voted on by a group of specialists. RESULTS: The consensus includes 41 statements focused on 6 main drug classes: antibiotics, 5-aminosalicylate, corticosteroids, immunosuppressants, biologic therapies, and other therapies. The group suggested against the use of antibiotics or 5-aminosalicylate as induction or maintenance therapies. Corticosteroid therapies (including budesonide) can be used as induction, but not maintenance therapies. Among immunosuppressants, thiopurines should not be used for induction, but can be used for maintenance therapy for selected low-risk patients. Parenteral methotrexate was proposed for induction and maintenance therapy in patients with corticosteroid-dependent CD. Biologic agents, including tumor necrosis factor antagonists, vedolizumab, and ustekinumab, were recommended for patients failed by conventional induction therapies and as maintenance therapy. The consensus group was unable to clearly define the role of concomitant immunosuppressant therapies in initiation of treatment with a biologic agent. CONCLUSIONS: Optimal management of CD requires careful patient assessment, acknowledgement of patient preferences, evidence-based use of existing therapies, and thorough assessment to define treatment success.

Vaccination Guidelines for Patients With Immune-Mediated Disorders on Immunosuppressive Therapies.

BACKGROUND:: Patients with immune-mediated diseases on immunosuppressive therapies have more infectious episodes than healthy individuals, yet vaccination practices by physicians for this patient population remain suboptimal. OBJECTIVES:: To evaluate the safety and efficacy of vaccines in individuals exposed to immunosuppressive therapies and provide evidence-based clinical practice recommendations. METHODS:: A literature search for vaccination safety and efficacy in patients on immunosuppressive therapies (2009-2017) was conducted. Results were assessed using the Grading of Recommendation, Assessment, Development, and Evaluation system. RESULTS:: Several immunosuppressive therapies attenuate vaccine response. Thus, vaccines should be administered before treatment whenever feasible. Inactivated vaccines can be administered without treatment discontinuation. Similarly, evidence suggests that the live zoster vaccine is safe and effective while on select immunosuppressive therapy, although use of the subunit vaccine is preferred. Caution regarding other live vaccines is warranted. Drug pharmacokinetics, duration of vaccine-induced viremia, and immune response kinetics should be considered to determine appropriate timing of vaccination and treatment (re)initiation. Infants exposed to immunosuppressive therapies through breastmilk can usually be immunized according to local guidelines. Intrauterine exposure to immunosuppressive agents is not a contraindication for inactivated vaccines. Live attenuated vaccines scheduled for infants and children ⩾12 months of age, including measles, mumps, rubella, and varicella, can be safely administered as sufficient time has elapsed for drug clearance. CONCLUSIONS:: Immunosuppressive agents may attenuate vaccine responses, but protective benefit is generally maintained. While these recommendations are evidence based, they do not replace clinical judgment, and decisions regarding vaccination must carefully assess the risks, benefits, and circumstances of individual patients.

Stricturing and Fistulizing Crohn's Disease Is Associated with Anti-tumor Necrosis Factor-Induced Psoriasis in Patients with Inflammatory Bowel Disease.

BACKGROUND: Paradoxical development of psoriasis in patients on anti-TNF agents has been increasingly reported. AIM: The aim was to characterize the prevalence and clinical characteristics of anti-TNF-associated psoriasis in a large cohort of inflammatory bowel disease patients. METHODS: Medical records of patients with Crohn's disease or ulcerative colitis treated with anti-TNF therapy at a single, tertiary IBD center were identified between 2004 and 2016. Patients identified as having developed psoriasis while on anti-TNF underwent detailed retrospective review of dermatologic features and changes in IBD treatment prompted by the development of psoriasis. RESULTS: Among 676 patients treated with anti-TNF (infliximab or adalimumab), the incidence of psoriasis was 10.7% (N = 72). Female gender (OR 1.88 [95% CI 1.12-3.17], p = 0.017), stricturing or fistulizing Crohn's disease (OR 1.83 [95% CI 1.04-3.21], p = 0.036) and upper GI Crohn's disease (OR 3.03 [95% CI 1.06-8.33], p = 0.039) were associated with psoriasis development. The median time to psoriasis onset was 569 days from initiation of anti-TNF, with onset occurring earlier in patients who developed psoriasis on adalimumab versus infliximab (457 vs. 790.5 days, p = 0.008). Overall, in 15/72 (20.8%), cases, cessation of the anti-TNF was required as a result of psoriasis. Plaque psoriasis was the most common type of psoriatic lesion (75%). Topical corticosteroids were the most common treatment for psoriasis. CONCLUSION: We report a high incidence of anti-TNF-associated psoriasis that was associated with female gender, foregut disease location, and fistulizing and stricturing disease behavior. More prospective studies and genetic analyses evaluating possible pathophysiologic underpinnings of this problem are needed.

Appendectomy does not decrease the risk of future colectomy in UC: results from a large cohort and meta-analysis.

OBJECTIVES: Early appendectomy is inversely associated with the development of UC. However, the impact of appendectomy on the clinical course of UC is controversial, generally favouring a milder disease course. We aim to describe the effect appendectomy has on the disease course of UC with focus on the timing of appendectomy in relation to UC diagnosis. DESIGN: Using the National Institute of Diabetes and Digestive and Kidney Diseases Inflammatory Bowel Disease Genetics Consortium database of patients with UC, the risk of colectomy was compared between patients who did and did not undergo appendectomy. In addition, we performed a meta-analysis of studies that examined the association between appendectomy and colectomy. RESULTS: 2980 patients with UC were initially included. 111 (4.4%) patients with UC had an appendectomy; of which 63 were performed prior to UC diagnosis and 48 after diagnosis. In multivariable analysis, appendectomy performed at any time was an independent risk factor for colectomy (OR 1.9, 95% CI 1.1 to 3.1), with appendectomy performed after UC diagnosis most strongly associated with colectomy (OR 2.2, 95% CI 1.1 to 4.5). An updated meta-analysis showed appendectomy performed either prior to or after UC diagnosis had no effect on colectomy rates. CONCLUSIONS: Appendectomy performed at any time in relation to UC diagnosis was not associated with a decrease in severity of disease. In fact, appendectomy after UC diagnosis may be associated with a higher risk of colectomy. These findings question the proposed use of appendectomy as treatment for UC.

Clinical practice guidelines for the medical management of nonhospitalized ulcerative colitis: the Toronto consensus.

BACKGROUND & AIMS: The medical management of ulcerative colitis (UC) has improved through the development of new therapies and novel approaches that optimize existing drugs. Previous Canadian consensus guidelines addressed the management of severe UC in the hospitalized patient. We now present consensus guidelines for the treatment of ambulatory patients with mild to severe active UC. METHODS: A systematic literature search identified studies on the management of UC. The quality of evidence and strength of recommendations were rated according to the Grading of Recommendation Assessment, Development and Evaluation (GRADE) approach. Statements were developed through an iterative online platform and then finalized and voted on by a working group of specialists. RESULTS: The participants concluded that the goal of therapy is complete remission, defined as both symptomatic and endoscopic remission without corticosteroid therapy. The consensus includes 34 statements focused on 5 main drug classes: 5-aminosalicylate (5-ASA), corticosteroids, immunosuppressants, anti-tumor necrosis factor (TNF) therapies, and other therapies. Oral and rectal 5-ASA are recommended first-line therapy for mild to moderate UC, with corticosteroid therapy for those who fail to achieve remission. Patients with moderate to severe UC should undergo a course of oral corticosteroid therapy, with transition to 5-ASA, thiopurine, anti-TNF (with or without thiopurine or methotrexate), or vedolizumab maintenance therapy in those who successfully achieve symptomatic remission. For patients with corticosteroid-resistant/dependent UC, anti-TNF or vedolizumab therapy is recommended. Timely assessments of response and remission are critical to ensuring optimal outcomes. CONCLUSIONS: Optimal management of UC requires careful patient assessment, evidence-based use of existing therapies, and thorough assessment to define treatment success.

Genome-wide association study identifies new susceptibility loci for Crohn disease and implicates autophagy in disease pathogenesis.

We present a genome-wide association study of ileal Crohn disease and two independent replication studies that identify several new regions of association to Crohn disease. Specifically, in addition to the previously established CARD15 and IL23R associations, we identified strong and significantly replicated associations (combined P < 10(-10)) with an intergenic region on 10q21.1 and a coding variant in ATG16L1, the latter of which was also recently reported by another group. We also report strong associations with independent replication to variation in the genomic regions encoding PHOX2B, NCF4 and a predicted gene on 16q24.1 (FAM92B). Finally, we demonstrate that ATG16L1 is expressed in intestinal epithelial cell lines and that functional knockdown of this gene abrogates autophagy of Salmonella typhimurium. Together, these findings suggest that autophagy and host cell responses to intracellular microbes are involved in the pathogenesis of Crohn disease.

The probiotic VSL#3 has anti-inflammatory effects and could reduce endoscopic recurrence after surgery for Crohn's disease.

BACKGROUND & AIMS: Probiotic formulations of single species of bacteria have not been effective in preventing the recurrence of Crohn's disease after surgery. We investigated the ability of VSL#3, a mixture of 8 different bacterial probiotic species, to prevent Crohn's disease recurrence after surgery in a multicenter, randomized, double-blind, placebo-controlled trial. METHODS: Within 30 days of ileocolonic resection and re-anastomosis, patients with Crohn's disease were randomly assigned to groups given 1 sachet of VSL#3 (900 billion viable bacteria, comprising 4 strains of Lactobacillus, 3 strains of Bifidobacterium, and 1 strain of Streptococcus salivarius subspecies thermophilus) (n = 59) or matching placebo (n = 60). Colonoscopy was performed at days 90 and 365 to evaluate the neoterminal ileum for disease recurrence and obtain mucosal biopsies for cytokine analysis. Patients from both groups with either no or mild endoscopic recurrence at day 90 received VSL#3 until day 365. The primary outcome was the proportion of patients with severe endoscopic recurrence at day 90. RESULTS: At day 90, the proportion of patients with severe endoscopic lesions did not differ significantly between VSL#3 (9.3%) and placebo (15.7%, P = .19). The proportions of patients with non-severe lesions at day 90 who had severe endoscopic recurrence at day 365 were 10.0% in the early VSL#3 group (given VSL#3 for the entire 365 days) and 26.7% in the late VSL#3 group (given VSL#3 from days 90 through 365) (P = .09). Aggregate rates of severe recurrence (on days 90 and 365) were not statistically different, 20.5% of subjects in the early VSL#3 group and 42.1% in the late VSL#3 group. Patients receiving VSL#3 had reduced mucosal inflammatory cytokine levels compared with placebo at day 90 (P < .05). Crohn's disease activity index and inflammatory bowel disease quality of life scores were similar in the 2 groups. CONCLUSIONS: There were no statistical differences in endoscopic recurrence rates at day 90 between patients who received VSL#3 and patients who received placebo. Lower mucosal levels of inflammatory cytokines and a lower rate of recurrence among patients who received early VSL#3 (for the entire 365 days) indicate that this probiotic should be further investigated for prevention of Crohn's disease recurrence. Clinical trials.gov number: NCT00175292.

Oral budesonide for induction of remission in ulcerative colitis.

BACKGROUND: Corticosteroids are first-line therapy for induction of remission in ulcerative colitis. Although corticosteroids may improve symptoms, they have significant adverse effects. Steroids which act topically, with less systemic side-effects may be more desirable. Budesonide is a topically acting corticosteroid with extensive first pass hepatic metabolism. There are currently three formulations of budesonide: two standard formulations including a controlled-ileal release capsule and a pH-dependent capsule both designed to release the drug in the distal small intestine and right colon; and the newer Budesonide-MMX® capsule designed to release the drug throughout the entire colon. OBJECTIVES: The primary objective was to evaluate the efficacy and safety of oral budesonide for the induction of remission in ulcerative colitis. SEARCH METHODS: We searched MEDLINE, EMBASE, CENTRAL, and the Cochrane IBD Group Specialised Register from inception to April 2015. We also searched reference lists of articles, conference proceedings and ClinicalTrials.gov. SELECTION CRITERIA: Randomised controlled trials comparing oral budesonide to placebo or another active therapy for induction of remission in ulcerative colitis were considered eligible. There were no exclusions based on patient age or the type, dose, duration or formulation of budesonide therapy. DATA COLLECTION AND ANALYSIS: Two independent investigators reviewed studies for eligibility, extracted data and assessed study quality. Methodological quality was assessed using the Cochrane risk of bias tool. The overall quality of the evidence supporting the outcomes was evaluated using the GRADE criteria. The primary outcome was induction of remission (as defined by the primary studies) at week eight. Secondary outcomes included clinical, endoscopic and histologic improvement, adverse events and early withdrawal. We calculated the risk ratio (RR) and corresponding 95% confidence interval (CI) for each dichotomous outcome and the mean difference (MD) and corresponding 95% CI for each continuous outcome. Data were analysed on an intention-to-treat basis. MAIN RESULTS: Six studies (1808 participants) were included. Four studies compared budesonide-MMX® with placebo, one small pilot study looked at clinical remission at week four, and was subsequently followed by three large, studies that assessed combined clinical and endoscopic remission at week eight. Although two placebo-controlled studies had mesalamine and Entocort (standard budesonide) treatment arms, these studies were not sufficiently powered to compare Budesonide-MMX® with these active comparators. One small study compared standard budesonide with prednisolone and one study compared standard budesonide to mesalamine. Four studies were rated as low risk of bias and two studies had an unclear risk of bias. A pooled analysis of three studies (900 participants) showed that budesonide-MMX® 9 mg was significantly superior to placebo for inducing remission (combined clinical and endoscopic remission) at 8 weeks. Fifteen per cent (71/462) of budesonide-MMX® 9 mg patients achieved remission compared to 7% (30/438) of placebo patients (RR 2.25, 95% CI 1.50 to 3.39). A GRADE analysis indicated that the overall quality of the evidence supporting this outcome was moderate due to sparse data (101 events). A subgroup analysis by concurrent mesalamine use suggests higher efficacy in the 442 patients who were not considered to be mesalamine-refractory (RR 2.89, 95% CI 1.59 to 5.25). A subgroup analysis by disease location suggests budesonide is most effective in patients with left-sided disease (RR 2.98, 95% CI 1.56 to 5.67; 289 patients). A small pilot study reported no statistically significant difference in endoscopic remission between budesonide and prednisolone (RR 0.75, 95% CI 0.23 to 2.42; 72 patients). GRADE indicated that the overall quality of the evidence supporting this outcome was very low due to unclear risk of bias and very sparse data (10 events). Standard oral budesonide was significantly less likely to induce clinical remission than oral mesalamine after 8 weeks of therapy (RR 0.72, 95% CI 0.57 to 0.91; 1 study, 343 patients). A GRADE analysis indicated that the overall quality of the evidence supporting this outcome was moderate due to sparse data (161 events). Another study found no difference in remission rates between budesonide-MMX® 9 mg and mesalamine (RR 1.48, 95% CI 0.81 to 2.71; 247 patients). GRADE indicated that the overall quality of the evidence supporting this outcome was low due to very sparse data (37 events). One study found no difference in remission rates between budesonide-MMX® 9 mg and standard budesonide 9 mg (RR 1.38, 95% CI 0.72 to 2.65; 212 patients). A GRADE analysis indicated that the overall quality of the evidence supporting this outcome was low due to very sparse data (32 events). Suppression of plasma cortisol was more common in prednisolone-treated patients (RR 0.02, 95% CI 0.0 to 0.33). While budesonide does appear to suppress morning cortisol to some extent, mean morning cortisol values remained within the normal range in 2 large studies (n = 899) and there was no difference in glucocorticoid-related side-effects across different treatment groups. Further, study withdrawal due to adverse events was not more common in budesonide compared with placebo treated patients (RR 0.85, 95% CI 0.53 to 1.38). Common adverse events included worsening ulcerative colitis, headache, pyrexia, insomnia, back pain, nausea, abdominal pain, diarrhoea, flatulence and nasopharyngitis. AUTHORS' CONCLUSIONS: Moderate quality evidence to supports the use of oral budesonide-MMX® at a 9 mg daily dose for induction of remission in active ulcerative colitis, particularly in patients with left-sided colitis. Budesonide-MMX® 9 mg daily is effective for induction of remission in the presence or absence of concurrent 5-ASA therapy. Further, budesonide-MMX® appears to be safe, and does not lead to significant impairment of adrenocorticoid function compared to placebo. Moderate quality evidence from a single study suggests that mesalamine may be superior to standard budesonide for the treatment of active ulcerative colitis. Low quality evidence from one study found no difference in remission rates between budesonide MMX® and mesalamine. Very low quality evidence from one small study showed no difference in endoscopic remission rates between standard budesonide and prednisolone. Low quality evidence from one study showed no difference in remission rates between budesonide-MMX® and standard budesonide. Adequately powered studies are needed to allow conclusions regarding the comparative efficacy and safety of budesonide versus prednisolone, budesonide-MMX® versus standard budesonide and budesonide versus mesalamine.