Prostaglandins and calprotectin are genetically and functionally linked to the Inflammatory Bowel Diseases.

BACKGROUND: Genome wide association studies (GWAS) have identified and validated more than 200 genomic loci associated with the inflammatory bowel disease (IBD), although for most the causal gene remains unknown. Given the importance of myeloid cells in IBD pathogenesis, the current study aimed to uncover the role of genes within IBD genetic loci that are endogenously expressed in this cell lineage. METHODS: The open reading frames (ORF) of 42 genes from IBD-associated loci were expressed via lentiviral transfer in the THP-1 model of human monocytes and the impact of each of these on the cell's transcriptome was analyzed using a RNA sequencing-based approach. We used a combination of genetic and pharmacologic approaches to validate our findings in the THP-1 line with further validation in human induced pluripotent stem cell (hiPSC)-derived-monocytes. RESULTS: This functional genomics screen provided evidence that genes in four IBD GWAS loci (PTGIR, ZBTB40, SLC39A11 and NFKB1) are involved in controlling S100A8 and S100A9 gene expression, which encode the two subunits of calprotectin (CP). We demonstrated that increasing PTGIR expression and/or stimulating PTGIR signaling resulted in increased CP expression in THP-1. This was further validated in hiPSC-derived monocytes. Conversely, knocking-down PTGIR endogenous expression and/or inhibiting PTGIR signaling led to decreased CP expression. These analyses were extended to the known IBD gene PTGER4, whereby its specific agonist also led to increased CP expression. Furthermore, we demonstrated that the PTGIR and PTGER4 mediated control of CP expression was dependent on signaling via adenylate cyclase and STAT3. Finally, we demonstrated that LPS-mediated increases in CP expression could be potentiated by agonists of PTGIR and PTGER4, and diminished by their antagonists. CONCLUSION: Our results support a causal role for the PTGIR, PTGER4, ZBTB40, SLC39A11 and NFKB1 genes in IBD, with all five genes regulating the expression of CP in myeloid cells, as well as potential roles for the prostacyclin/prostaglandin biogenesis and signaling pathways in IBD susceptibility and pathogenesis.

After surgically induced remission, ileal and colonic mucosa-associated microbiota predicts Crohn's disease recurrence.

BACKGROUND AND AIMS: Investigating the tissue-associated microbiota after surgically induced remission may help to understand the mechanisms initiating intestinal inflammation in Crohn's disease. METHODS: Crohn's disease patients undergoing ileocolic resection were prospectively recruited in six academic centers. Biopsy samples from the neoterminal ileum, colon and rectosigmoid were obtained from colonoscopies performed after surgery. Microbial DNA was extracted for 16S rRNA gene sequencing. Microbial diversity and taxonomic differential relative abundance were analyzed. A random forest model was applied to analyze the performance of clinical and microbial features to predict recurrence. A Rutgeerts score ≥i2 was deemed as endoscopic recurrence. RESULTS: A total of 349 postoperative colonoscopies and 944 biopsy samples from 262 Crohn's disease patients were analyzed. Ileal inflammation accounted for most of the explained variance of the ileal and colonic mucosa-associated microbiota. Samples obtained from 97 patients who were in surgically induced remission at first postoperative colonoscopy who went on to develop endoscopic recurrence at second colonoscopy showed lower diversity and microbial deviations when compared to patients who remained in endoscopic remission. Depletion of genus Anaerostipes and increase of several genera from class Gammaproteobacteria at the three biopsy sites increase the risk of further recurrence. Gut microbiome was able to predict future recurrence better than clinical features. CONCLUSION: Ileal and colonic mucosa-associated microbiome deviations precede development of new onset ileal inflammation after surgically induced remission and show good predictive performance for future recurrence. These findings suggest that targeted microbial modulation is a plausible modality to prevent postoperative Crohn's disease recurrence.

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.

Forecasting the Incidence and Prevalence of Inflammatory Bowel Disease: A Canadian Nationwide Analysis.

INTRODUCTION: Canada has a high burden of inflammatory bowel disease (IBD). Historical trends of IBD incidence and prevalence were analyzed to forecast the Canadian burden over the next decade. METHODS: Population-based surveillance cohorts in 8 provinces derived from health administrative data assessed the national incidence (2007-2014) and prevalence (2002-2014) of IBD. Autoregressive integrated moving average models were used to forecast incidence and prevalence, stratified by age, with 95% prediction intervals (PI), to 2035. The average annual percentage change (AAPC) with 95% confidence interval (CI) was calculated for the forecasted incidence and prevalence. RESULTS: The national incidence of IBD is estimated to be 29.9 per 100,000 (95% PI 28.3-31.5) in 2023. With a stable AAPC of 0.36% (95% CI -0.05 to 0.72), the incidence of IBD is forecasted to be 31.2 per 100,000 (95% PI 28.1-34.3) in 2035. The incidence in pediatric patients (younger than 18 years) is increasing (AAPC 1.27%; 95% CI 0.82-1.67), but it is stable in adults (AAPC 0.26%; 95% CI -0.42 to 0.82). The prevalence of IBD in Canada was 843 per 100,000 (95% PI 716-735) in 2023 and is expected to steadily climb (AAPC 2.43%; 95% CI 2.32-2.54) to 1,098 per 100,000 (95% PI 1,068-1,127) by 2035. The highest prevalence is in seniors with IBD (1,174 per 100,000 in 2023; AAPC 2.78%; 95% CI 2.75-2.81). DISCUSSION: Over the next decade, the Canadian health care systems will contend with the juxtaposition of rising incidence of pediatric IBD and a rising prevalence of overall IBD driven by the aging population.

Proton pump inhibitors and the risk of inflammatory bowel disease: population-based cohort study.

OBJECTIVE: To determine whether the use of proton pump inhibitors (PPIs) compared with the use of histamine-2 receptor antagonists (H2RAs) is associated with an increased risk of inflammatory bowel disease (IBD). DESIGN: Population-based cohort study designed to address the impact of protopathic bias. SETTING: General practices contributing data to the UK Clinical Practice Research Datalink GOLD. PARTICIPANTS: 1 498 416 initiators of PPIs and 322 474 initiators of H2RAs from 1 January 1990 to 31 December 2018, with follow-up until 31 December 2019. Patients were analysed according to the timing of the IBD diagnosis after treatment initiation (early vs late). MAIN OUTCOME MEASURES: Standardised morbidity ratio weighted Cox proportional hazards models were used to estimate marginal HRs and 95% CIs. In the early-event analysis, IBD diagnoses were assessed within the first 2 years of treatment initiation, an analysis subject to potential protopathic bias. In the late-event analysis, all exposures were lagged by 2 years to account for latency and minimise protopathic bias. RESULTS: In the early-event analysis, the use of PPIs was associated with an increased risk of IBD within the first 2 years of treatment initiation, compared with H2RAs (HR 1.39, 95% CI 1.14 to 1.69). In contrast, the use of PPIs was not associated with an increased risk of IBD in the late-event analysis (HR 1.05, 95% CI 0.90 to 1.22). The results remained consistent in several sensitivity analyses. CONCLUSIONS: Compared with H2RAs, PPIs were not associated with an increased risk of IBD, after accounting for protopathic bias.

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.

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.

Impact of Endoscopic and Histologic Activity on Disease Relapse in Ulcerative Colitis.

INTRODUCTION: Endoscopic healing is currently considered the main target in the management of ulcerative colitis (UC). There are conflicting data about the role of histology as a stricter treatment objective. We aim at evaluating the additional benefit of histologic remission over endoscopic remission. METHODS: We performed a prospective observational study at the McGill University Health Center. We enrolled adult patients with UC in clinical remission for at least 3 months undergoing a colonoscopy. Endoscopic disease activity was based on the Mayo endoscopic score. Rectal biopsies were obtained, and the histologic activity was evaluated using the Geboes score (active disease defined as Geboes score ≥ 3.1) with the addition of assessing the presence of basal plasmacytosis. Patients were followed up for 12 months for disease relapse defined as a partial Mayo score of > 2. At the time of relapse or end of follow-up, all patients underwent repeat endoscopic evaluation. The primary end point was clinical relapse. RESULTS: Two hundred fifty-three patients were included. The presence of basal plasmacytosis was associated with relapse (adjusted odd ratio = 2.07, 95% confidence interval [CI] 1.06-4.18, P = 0.042). Time to clinical relapse was significantly higher for patients with Mayo endoscopic score > 0 with adjusted hazard ratio = 2.65, 95% CI 1.31-5.39, and P = 0.007. Time to clinical relapse was not significantly higher for Geboes score ≥ 3.1 with adjusted hazard ratio = 1.29, 95% CI 0.67-2.49, and P = 0.45. DISCUSSION: Active histologic disease did not affect time to clinical relapse in patients with UC who achieved endoscopic remission while the presence of basal plasmacytosis is associated with relapse.

Fucosyltransferase 2 Mutations Are Associated With a Favorable Clinical Course in Crohn's Disease.

BACKGROUND: Fucosyltransferase 2 (FUT2) participates in intestinal antigen secretion and bacterial adherence. FUT2 homozygous nonsense mutations (FUT2M) and subsequent nonsecretor status is associated with Crohn's disease (CD). The common null allele is rs601338. We assessed the relationship between FUT2M and disease course. METHODS: In consecutive adult CD outpatients, clinical, biochemical, and genetic data were collected at baseline visits. Patients were longitudinally followed over 5 years. The primary outcome analyzed the relationship between FUT2M and rates of CD patients in persistent steroid-free clinical remission requiring neither surgery, biologics, nor immunomodulators. RESULTS: Sixty-two CD patients were recruited. FUT2M homozygotes (rs601338 or any mutation in linkage disequilibrium) were detected in 27% of CD (17/62). Patients with rs601338 mutations had higher rates of the primary outcome (homozygous: 46.6%, heterozygous: 28.0%, wild-type: 5.3%, P=0.02). Similar findings existed for CD patients with homozygous mutations in any single-nucleotide polymorphism for FUT2 (homozygous: 41.2%, heterozygous: 25.9%, wild-type: 5.6%, P=0.04). On multivariable analysis, rs601338 mutation was associated with the primary outcome (odds ratio=3.4, 95% confidence interval: 1.3-8.7, P=0.01), while other parameters were not. Mutation of rs601338 was associated with lower rates of penetrating disease (homozygous: 13.3%, heterozygous: 28.0%, wild-type: 52.6%, P=0.05) and particularly in high-risk patients (homozygous: 0%, heterozygous: 37.5%, wild-type: 83.3%, P=0.01). CONCLUSIONS: FUT2 mutation status is associated with a favorable clinical course in CD. Further confirmatory studies are needed.

Hospitalization With Clostridioides difficile in Pediatric Inflammatory Bowel Disease: a Population-Based Study.

OBJECTIVES: Several studies have demonstrated higher rates of Clostridioides difficile infection (CDI) in adults with inflammatory bowel disease (IBD). We conducted a population-based study comparing the risk of hospitalization with CDI in children with and without IBD. METHODS: Using health administrative data and validated algorithms, we identified all children (<16 years) diagnosed with IBD in 5 Canadian provinces, then age and sex matched to 5 children without IBD. Province-specific 5-year incidence rates of hospitalization with CDI were pooled and generalized linear mixed-effects models were used to estimate the crude incidence rate ratio (IRR) comparing (1) children with and without IBD and (2) children with Crohn disease and ulcerative colitis. Hazard ratios (HR) from Cox proportional hazards models adjusting for age, sex, rural/urban household, and income were pooled using fixed-effects models. RESULTS: The incidence rate of CDI identified during hospitalization was 49.06 [95% confidence interval (CI), 39.40-61.08] per 10,000 person-years (PY) in 3593 children with IBD compared to 0.39 (95% CI, 0.13-1.21) per 10,000 PY in 16,284 children without IBD (crude IRR, 133.4, 95% CI, 42.1-422.7; adjusted HR, 68.2, 95% CI, 24.4-190.4). CDI was identified less often in children with Crohn disease than ulcerative colitis (crude IRR, 0.51, 95% CI, 0.32-0.82; adjusted HR, 0.69, 95% CI, 0.46-1.05). CONCLUSIONS: Children with IBD have a markedly higher incidence of CDI identified during a hospitalization relative to children without IBD. Consequently, symptomatic children with IBD who are hospitalized should be screened for CDI.

Patient-Reported Outcome and Clinical Scores Are Equally Accurate in Predicting Mucosal Healing in Ulcerative Colitis: A Prospective Study.

BACKGROUND: Optimal management of patients with ulcerative colitis (UC) requires the accurate, objective assessment of disease activity. AIMS: We aimed to determine how strong patient-reported outcomes, clinical scores and symptoms correlate with endoscopy and biomarkers for assessment of disease activity in patients with UC. METHODS: Consecutive patients with UC followed at the McGill University IBD Center and referred for endoscopy (surveillance or flare) were included prospectively between September 2018 and August 2020. Patient-reported outcome (PRO2), partial Mayo, Simple Clinical Colitis Activity Index (SCCAI), Mayo endoscopic subscore (MES) and Baron and Ulcerative Colitis Endoscopic Index of Severity (UCEIS) scores were calculated. C-reactive protein (CRP) and fecal calprotectin (FCAL) were collected. RESULTS: A total of 171 patients with UC [age: 49(IQR:38-61) years, female: 46.2%, 57.3% extensive disease, 42.7% on biologicals] were included prospectively. Rectal bleeding (RBS), stool frequency (SF) subscore of 0, or total PRO2 remission (RBS0 and SF ≤ 1), partial Mayo (≤ 2) and SCCAI (≤ 2.5) remission were similarly associated with mucosal healing defined by MES (0 or ≤ 1), Baron (0 or ≤ 1) or UCEIS (≤ 3) scores in ROC analysis (AUC:0.93-0.72). There was a moderate-to-strong agreement between MES Baron and UCEIS (K = 0.91-0.41). A UCEIS of ≤ 3 was identified as the best cutoff to clinical or endoscopic remission. Agreement between CRP and clinical remission or endoscopic healing (MES/Baron) was poor (K ~ 0.2), while agreement between FCAL and RBS-PRO2 or MES/Baron/UCEIS was moderate to strong (K = 0.44-0.70). CONCLUSIONS: Agreement between RBS, SF, PRO2, partial Mayo and SCCAI in predicting endoscopic healing was moderate to strong, while no clinically meaningful difference was found in accuracy across the scores and definitions. FCAL, but not CRP, was associated to clinical and endoscopic remission.

Poor Drug Sustainability in Inflammatory Bowel Disease Patients in Clinical Remission on Thiopurine Monotherapy.

BACKGROUND: Immunomodulator monotherapy is an important component in the treatment of inflammatory bowel disease (IBD). However, there is conflicting literature about thiopurines maintaining long-term remission in patients with active IBD. AIM: To determine the durable clinical remission rate in adults with Crohn's disease (CD) or ulcerative colitis (UC) on thiopurine monotherapy over 5 years. METHODS: We performed a retrospective analysis of adult patients identified at McGill University Health Centre from 2009 to 2012. We included IBD patients who initiated thiopurine monotherapy and were in remission for at least 3 months (Harvey-Bradshaw Index (HBI) < 5 points for CD and partial Mayo Score (pMS) < 2 points in UC). The primary endpoint was sustained clinical remission on thiopurines during a 5-year follow-up. This included patients who had not relapsed or discontinued the drug due to side effects. The secondary endpoint was clinical relapse over the follow-up period, which was defined as HBI > 5 in CD and pMS > 2 in UC. RESULTS: There were 148 patients included in the study (100 CD; 48 UC). At 5 years, 23% (34/148) patients remained in clinical remission on thiopurine monotherapy (25 CD and 9 UC patients). Thirty-three percent (33/100) of CD and 46% (22/48) of UC patients relapsed while on thiopurines. There was no difference in relapse rates between CD and UC patients. Eighty-four percent (42/50) of patients with CD with side effects and all UC (17/17) patients who experienced side effects discontinued the drug. CONCLUSION: This analysis demonstrates that there is poor sustainability of clinical remission in IBD patients on thiopurine monotherapy given that a high proportion of patients discontinue thiopurines due to either relapse or side effects.

Past and Future Burden of Inflammatory Bowel Diseases Based on Modeling of Population-Based Data.

BACKGROUND & AIMS: Inflammatory bowel diseases (IBDs) exist worldwide, with high prevalence in North America. IBD is complex and costly, and its increasing prevalence places a greater stress on health care systems. We aimed to determine the past current, and future prevalences of IBD in Canada. METHODS: We performed a retrospective cohort study using population-based health administrative data from Alberta (2002-2015), British Columbia (1997-2014), Manitoba (1990-2013), Nova Scotia (1996-2009), Ontario (1999-2014), Quebec (2001-2008), and Saskatchewan (1998-2016). Autoregressive integrated moving average regression was applied, and prevalence, with 95% prediction intervals (PIs), was forecasted to 2030. Average annual percentage change, with 95% confidence intervals, was assessed with log binomial regression. RESULTS: In 2018, the prevalence of IBD in Canada was estimated at 725 per 100,000 (95% PI 716-735) and annual average percent change was estimated at 2.86% (95% confidence interval 2.80%-2.92%). The prevalence in 2030 was forecasted to be 981 per 100,000 (95% PI 963-999): 159 per 100,000 (95% PI 133-185) in children, 1118 per 100,000 (95% PI 1069-1168) in adults, and 1370 per 100,000 (95% PI 1312-1429) in the elderly. In 2018, 267,983 Canadians (95% PI 264,579-271,387) were estimated to be living with IBD, which was forecasted to increase to 402,853 (95% PI 395,466-410,240) by 2030. CONCLUSION: Forecasting prevalence will allow health policy makers to develop policy that is necessary to address the challenges faced by health systems in providing high-quality and cost-effective care.

Low Rate of Drug Discontinuation, Frequent Need for Dose Adjustment, and No Association with Development of New Arthralgia in Patients Treated with Vedolizumab: Results from a Tertiary Referral IBD Center.

BACKGROUND: Evaluating clinical data on the safety and efficacy of vedolizumab (VDZ) in 'real-world' setting is still desirable. Recent reports have raised concerns that arthralgia may be associated with VDZ. AIMS: The aim of this study is to present clinical experience with VDZ from a tertiary IBD center. METHODS: Retrospective chart reviews were performed of consecutive patients exposed to VDZ between 2015 and 2018. Clinical, biomarker, and endoscopic efficacy and safety data were evaluated. RESULTS: A total of 130 IBD (75CD, 55UC) patients were included. Median duration of VDZ therapy was 65 weeks. Probability of drug discontinuation was 4.9% and 9.4% at 1 and 2 years. Dose intensification was more frequent in CD compared to UC (at 1 and 2 years: 64.8/87.9% vs. 26.5/35.7%, p < 0.001). Clinical remission rates at 3-, 6- and 12 months were 44.4%, 71.4% and 77.1% in UC, and 9.1%, 26.7% and 29.2% in CD patients, respectively. Prior use of multiple biologic agents was associated with diminished efficacy of VDZ in CD. Three new cases of arthralgia were encountered during follow-up. CONCLUSION: Vedolizumab (VDZ) therapy displayed good drug sustainability and clinical efficacy in a population with severe disease phenotype and high rates of previous anti-TNF failure. Frequent dose intensification was required. The safety profile was good, and no association between newly onset arthralgia and VDZ therapy was observed.

Clinical Parameters Correlate With Endoscopic Activity of Ulcerative Colitis: A Systematic Review.

BACKGROUND & AIMS: Optimal management of patients with ulcerative colitis (UC) requires assessment of disease activity-usually by endoscopy, which is invasive, costly, and not risk free. We performed a systematic review to determine whether clinical symptoms correlate with findings from endoscopy assessments of patients with UC. METHODS: We performed a systematic review of publication databases from January 1980 through July 2018 to identify clinical trials and observational studies reporting correlations among symptoms, disease activity index scores and/or patient reported outcomes (rectal bleeding and/or stool frequency), and endoscopic disease activity. Correlations were ascertained in patients with active vs inactive disease and by disease extent and treatment type. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies 2 tool. Because of significant heterogeneity, meta-analysis was not possible. Results were synthesized qualitatively and systematically. RESULTS: Our final analysis included 23 studies (1 randomized trial, 22 observational studies) comprising 3320 patients with UC. The studies used a variety of measures to assess clinical activity, endoscopic activity, and measures of correlation (sensitivity, specificity, correlation coefficients, area under the receiver operator curve). Overall, studies were at moderate-high risk of bias. Composite clinical measures, including rectal bleeding and stool frequency, had moderate to strong correlations with endoscopic disease activity; the absence of rectal bleeding identified patients with inactive disease with higher levels of sensitivity than normalization of stool frequency. In general, symptoms correlated more strongly with endoscopic activity in patients with left-sided colitis than extensive colitis. The effect of different medications on the correlation between clinical and endoscopic activity has not been well studied. CONCLUSIONS: In a systematic review, we found a moderate to strong correlation between clinical activity, particularly the combination of rectal bleeding and stool frequency, and endoscopic activity in patients with UC. Although these clinical assessments could help prioritize patients for endoscopic evaluation in resource-limited settings, challenges associated with treating patients based on symptoms alone preclude adaptation of current management algorithms.

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.

Sex-Based Differences in Incidence of Inflammatory Bowel Diseases-Pooled Analysis of Population-Based Studies From Western Countries.

BACKGROUND & AIMS: Although the incidence of inflammatory bowel diseases (IBDs) varies with age, few studies have examined variations between the sexes. We therefore used population data from established cohorts to analyze sex differences in IBD incidence according to age at diagnosis. METHODS: We identified population-based cohorts of patients with IBD for which incidence and age data were available (17 distinct cohorts from 16 regions of Europe, North America, Australia, and New Zealand). We collected data through December 2016 on 95,605 incident cases of Crohn's disease (CD) (42,831 male and 52,774 female) and 112,004 incident cases of ulcerative colitis (UC) (61,672 male and 50,332 female). We pooled incidence rate ratios of CD and UC for the combined cohort and compared differences according to sex using random effects meta-analysis. RESULTS: Female patients had a lower risk of CD during childhood, until the age range of 10-14 years (incidence rate ratio, 0.70; 95% CI, 0.53-0.93), but they had a higher risk of CD thereafter, which was statistically significant for the age groups of 25-29 years and older than 35 years. The incidence of UC did not differ significantly for female vs male patients (except for the age group of 5-9 years) until age 45 years; thereafter, men had a significantly higher incidence of ulcerative colitis than women. CONCLUSIONS: In a pooled analysis of population-based studies, we found age at IBD onset to vary with sex. Further studies are needed to investigate mechanisms of sex differences in IBD incidence.

Inflammatory bowel disease patient perceptions of diagnostic and monitoring tests and procedures.

BACKGROUND: Inflammatory Bowel Disease (IBD) with its high incidence and prevalence rates in Canada generates a heavy burden of tests and procedures. The purpose of this study is to gain a better understanding of the transfer of information from physician to patient, as well as the patient understanding and perceptions about the tests and procedures that are ordered to them in the context of IBD diagnosis and monitoring. METHODS: An online questionnaire was completed by 210 IBD patients in Canada. Information on the five most-often used tests or procedures in IBD diagnosis/monitoring was collected. These include: general blood test, colonoscopy, colon biopsy, medical imaging and stool testing. RESULTS: The general blood test is both the most ordered and most refused tool. It is also the one with which patients are the least comfortable, the one that generates the least concern and the one about which physicians provide the least information. The stool test is the test/procedure with which patients are the most comfortable. Procedures raise more concerns among patients and physicians provide more information about why they are needed, their impact and the risks they present. Very little information is provided to patients about the risks of having false positives or negative tests. CONCLUSIONS: This study provides an initial understanding of patient perceptions, the transfer of information from a physician to a patient and a patient's understanding of the tests and procedures that will be required to treat IBD throughout what is a lifelong disease. The present study takes a first step in better understanding the acceptance of the test or procedure by IBD patients, which is essential for them to adhere to the monitoring process.

High-Dose Infliximab Rescue Therapy for Hospitalized Acute Severe Ulcerative Colitis Does Not Improve Colectomy-Free Survival.

BACKGROUND AND OBJECTIVE: Optimization strategies with infliximab (IFX) are increasingly used as rescue therapy for steroid refractory acute severe ulcerative colitis (ASUC). We aim to determine if intensified IFX induction improves colectomy rate and identifies outcome predictors. METHODS: Hospitalized adult patients who received IFX for ASUC between 2010 and 2016 were identified. We compared standard inductions (5 mg/kg) vs high-dose induction (10 mg/kg) with 3-month colectomy rate as primary outcome. RESULTS: Seventy-two patients (62.5% male, median age 38.5) were identified. Thirty-seven patients (51.3%) received 5 mg/kg IFX and 35 received 10 mg/kg. Baseline clinical, biochemical and endoscopic parameters were well matched between these two groups. 10 mg/kg was more likely to be used by clinicians from 2014 onwards (p < 0.001). Three-month colectomy rate was 9.7%; which was not significantly different between the standard (5.4%) and high-dose (14.3%) IFX induction (p = 0.205). CRP ≥ 60 (OR 10.9 [95% CI 1.23-96.50], p = 0.032), hemoglobin ≤ 90 g/L (OR 15.6 [95% CI 2.61-92.66], p = 0.036) and albumin < 30 g/L (OR 9.4 [95% CI 1.06-83.13], p = 0.044) were associated with increased risk of colectomy at 3 months in univariate regression analysis. CONCLUSION: Use of high-dose infliximab rescue therapy did not improve 3-month colectomy-free survival in this cohort. Tailored use in high-risk patients may be beneficial although further validation is required.

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.