Recent advances in clinical practice: a systematic review of isolated colonic Crohn's disease: the third IBD?

First United Arab Emirates consensus on diagnosis and management of inflammatory bowel diseases: A 2020 Delphi consensus

Ulcerative colitis and Crohn's disease are the main entities of inflammatory bowel disease characterized by chronic remittent inflammation of the gastrointestinal tract. The incidence and prevalence are on the rise worldwide, and the heterogeneity between patients and within individuals over time is striking. The progressive advance in our understanding of the etiopathogenesis coupled with an unprecedented increase in therapeutic options have changed the management towards evidence-based interventions by clinicians with patients. This guideline was stimulated and supported by the Emirates Gastroenterology and Hepatology Society following a systematic review and a Delphi consensus process that provided evidence- and expert opinion-based recommendations. Comprehensive up-to-date guidance is provided regarding diagnosis, evaluation of disease severity, appropriate and timely use of different investigations, choice of appropriate therapy for induction and remission phase according to disease severity, and management of main complications.

The use of 5-aminosalicylate for patients with Crohn's disease in a prospective European inception cohort with 5 years follow-up - an Epi-IBD study

BACKGROUND

The lack of scientific evidence regarding the effectiveness of 5-aminosalicylate in patients with Crohn's disease is in sharp contrast to its widespread use in clinical practice.

AIMS

The aim of the study was to investigate the use of 5-aminosalicylate in patients with Crohn's disease as well as the disease course of a subgroup of patients who were treated with 5-aminosalicylate as maintenance monotherapy during the first year of disease.

METHODS

In a European community-based inception cohort, 488 patients with Crohn's disease were followed from the time of their diagnosis. Information on clinical data, demographics, disease activity, medical therapy and rates of surgery, cancers and deaths was collected prospectively. Patient management was left to the discretion of the treating gastroenterologists.

RESULTS

Overall, 292 (60%) patients with Crohn's disease received 5-aminosalicylate period during follow-up for a median duration of 28 months (interquartile range 6-60). Of these, 78 (16%) patients received 5-aminosalicylate monotherapy during the first year following diagnosis. Patients who received monotherapy with 5-aminosalicylate experienced a mild disease course with only nine (12%) who required hospitalization, surgery, or developed stricturing or penetrating disease, and most never needed more intensive therapy. The remaining 214 patients were treated with 5-aminosalicylate as the first maintenance drug although most eventually needed to step up to other treatments including immunomodulators (75 (35%)), biological therapy (49 (23%)) or surgery (38 (18%)).

CONCLUSION

In this European community-based inception cohort of unselected Crohn's disease patients, 5-aminosalicylate was commonly used. A substantial group of these patients experienced a quiescent disease course without need of additional treatment during follow-up. Therefore, despite the controversy regarding the efficacy of 5-aminosalicylate in Crohn's disease, its use seems to result in a satisfying disease course for both patients and physicians.

Dietary Inflammatory Potential and Risk of Crohn's Disease and Ulcerative Colitis

BACKGROUND & AIMS

Inflammation is a potential mechanism through which diet modulates the onset of inflammatory bowel disease. We analyzed data from 3 large prospective cohorts to determine the effects of dietary inflammatory potential on the risk of developing Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

We collected data from 166,903 women and 41,931 men in the Nurses' Health Study (1984-2014), Nurses' Health Study II (1991-2015), and Health Professionals Follow-up Study (1986-2012). Empirical dietary inflammatory pattern (EDIP) scores were calculated based on the weighted sums of 18 food groups obtained via food frequency questionnaires. Self-reported CD and UC were confirmed by medical record review. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

We documented 328 cases of CD and 428 cases of UC over 4,949,938 person-years of follow-up. The median age at IBD diagnosis was 55 years (range 29-85 years). Compared with participants in the lowest quartile of cumulative average EDIP score, those in the highest quartile (highest dietary inflammatory potential) had a 51% higher risk of CD (HR 1.51; 95% CI 1.10-2.07; Ptrend = .01). Compared with participants with persistently low EDIP scores (at 2 time points, separated by 8 years), those with a shift from a low to high inflammatory potential of diet or persistently consumed a proinflammatory diet had greater risk of CD (HR 2.05; 95% CI 1.10-3.79 and HR 1.77; 95% CI 1.10-2.84). In contrast, dietary inflammatory potential was not associated with the risk of developing UC (Ptrend = .62).

CONCLUSIONS

In an analysis of 3 large prospective cohorts, we found dietary patterns with high inflammatory potential to be associated with increased risk of CD but not UC.

Anatomical Variation in Mesenteric Macrophage Phenotypes in Crohn's Disease

INTRODUCTION

Clinical trials are currently investigating whether an extended mesenteric resection for ileocecal resections could reduce postoperative recurrence in Crohn's disease. Resection of the mesorectum, which contains proinflammatory macrophages, during proct(ocol)ectomy, is associated with reduced recurrent inflammation and improved wound healing. We aimed to characterize the macrophages in the ileocecal mesentery, which were compared with those in the mesorectum, to provide a biological rationale for the ongoing trials.

METHODS

In 13 patients with Crohn's disease and 4 control patients undergoing a proctectomy, tissue specimens were sampled at 3 locations from the mesorectum: distal (rectum), middle, and proximal (sigmoid). In 38 patients with Crohn's disease and 7 control patients undergoing ileocecal resections, tissue specimens also obtained from 3 locations: adjacent to the inflamed terminal ileum, adjacent to the noninflamed ileal resection margin, and centrally along the ileocolic artery. Immune cells from these tissue specimens were analyzed by flow cytometry for expression of CD206 to determine their inflammatory status.

RESULTS

In the mesorectum, a gradient from proinflammatory to regulatory macrophages from distal to proximal was observed, corresponding to the adjacent inflammation of the intestine. By contrast, the ileocecal mesentery did not contain high amounts of proinflammatory macrophages adjacent to the inflamed tissue, and a gradient toward a more proinflammatory phenotype was seen in the central mesenteric area.

DISCUSSION

Although the mesentery is a continuous structure, the mesorectum and the ileocecal mesentery show different immunological characteristics. Therefore, currently, there is no basis to perform an extended ileocecal resection in patients with Crohn's disease.

Early Combined Immunosuppression May Be More Effective for Reducing Complications in Isolated Colonic- vs Ileal-Dominant Crohn Disease

BACKGROUND

We assessed whether differential efficacy of early combined immunosuppression (ECI) in comparison with conventional management (CM) is present in patients with Crohn disease (CD) according to disease location.

METHODS

In this posthoc analysis of the Randomized Evaluation of an Algorithm for Crohn's Treatment trial, the effect of ECI vs CM modified by disease location (isolated-colonic vs ileal-dominant) in terms of time to first complication (hospitalization, surgery, or disease-related complications-presence of a new abscess, fistula, or stricture; serious worsening of disease activity; extraintestinal manifestations) was analyzed using a marginal Cox proportional hazard model to account for cluster randomization. Factors adjusted included practice size, country, and other covariates selected in a backward logistic regression analysis with the first composition as outcome and P < 0.10.

RESULTS

Of the 1969 patients with CD, 435 had isolated colonic CD (ECI n = 257, CM n = 178) and 1534 had ileal CD (ECI n = 817, CM n = 717). Over 24 months there was a significant differential impact for ECI vs CM for reducing the risk of a CD-related complication between patients with colonic CD and ileal CD (colonic CD hazard ratio [HR] = 0.51; 95% CI, 0.30-0.85 vs ileal CD HR = 0.79; 95% CI, 0.57-1.10; P = 0.033). No difference was identified between ECI vs CM for reducing the risk of surgery (colonic HR = 0.52 vs ileal HR = 0.74; P = 0.468) or hospitalization (colonic HR = 0.77 vs ileal HR = 0.83; P = 0.806).

CONCLUSIONS

In this posthoc analysis of the Randomized Evaluation of an Algorithm for Crohn's Treatment trial, symptom-based ECI was associated with greater efficacy for reducing the risk of CD-related complications in patients with colonic disease location relative to ileal disease location.

What Factors Are Associated With the Eventual Need for an Ileostomy After Total Abdominal Colectomy and Ileosigmoid or Ileorectal Anastomosis for Crohn's Colitis in the Biologic Era?

BACKGROUND

Outcomes after total abdominal colectomy with ileosigmoid or ileorectal anastomosis for Crohn's colitis and risk factors for requirement of a permanent ileostomy remain poorly understood, particularly in the biologic era.

OBJECTIVE

This study aimed to determine long-term ostomy-free survival after ileosigmoid or ileorectal anastomosis for Crohn's colitis and potential risk factors for requirement of an ileostomy.

DESIGN

This is a retrospective cohort study.

SETTING

This study was conducted at a single-institution IBD tertiary referral center.

PATIENTS

Patients diagnosed with Crohn's disease and undergoing ileosigmoid or ileorectal anastomosis between 2006 and 2018 were selected.

MAIN OUTCOME MEASURE

Long-term ostomy-free survival and hazard ratios of potential predictors of ileostomy requirement were the primary outcomes measured.

RESULTS

One hundred nine patients (56% female) underwent ileosigmoid or ileorectal anastomosis for Crohn's disease. The majority of surgical procedures were completed in 2 or 3 stages (53%). The indication for total abdominal colectomy was predominantly medically refractory disease (77%), with dysplasia the second leading indication (13%). At an overall mean follow-up of 3 years, 16 patients had undergone either proctectomy or diversion with the rectum in situ. This resulted in ostomy-free survival estimates at 5 and 10 years of 78% (95% CI, 68-90) and 58% (95% CI, 35-94). A positive distal microscopic margin was the only risk factor for later requirement of a permanent ileostomy (HR, 5.4; 95% CI, 1.7-17.2).

LIMITATIONS

This study is limited because it is a retrospective study at a tertiary referral center.

CONCLUSIONS

Long-term ostomy-free survival can be achieved in the majority of patients who undergo restoration of intestinal continuity after total abdominal colectomy for Crohn's colitis. A positive distal microscopic margin was independently associated with long-term anastomotic failure, and it should be accounted for when risk stratifying patients for postoperative prophylactic medical therapy. See Video Abstract at http://links.lww.com/DCR/B111. ¿QUÉ FACTORES ESTÁN ASOCIADOS CON LA EVENTUAL NECESIDAD DE UNA ILEOSTOMÍA DESPUÉS DE UNA COLECTOMÍA ABDOMINAL TOTAL Y UNA ANASTOMOSIS ILEOSIGMOIDEA O ILEORRECTAL PARA LA COLITIS DE CROHN EN LA ERA BIOLÓGICA?: Los resultados después de la colectomía abdominal total con anastomosis ileosigmoidea o ileorrectal para la colitis de Crohn y los factores de riesgo para el requerimiento de una ileostomía permanente siguen siendo poco conocidos, particularmente en la era biológica.Determinar la supervivencia a largo plazo sin ostomía después de una anastomosis ileosigmoidea o ileorrectal para la colitis de Crohn y los factores de riesgo potenciales para la necesidad de una ileostomía.Estudio de cohorte retrospectivo.Centro de referencia de tercel nivel para enfermedad inflamatoria intestinal de una sola institución.Pacientes diagnosticados con enfermedad de Crohn y sometidos a anastomosis ileosigmoidea o ileorrectal entre 2006 y 2018Supervivencia a largo plazo sin ostomías y cocientes de riesgo de predictores potenciales de requerimiento de ileostomía109 pacientes (56% mujeres) se sometieron a anastomosis ileosigmoidea o ileorrectal por enfermedad de Crohn. La mayoría de los procedimientos quirúrgicos se completaron en 2 o 3 etapas (53%). La indicación de colectomía abdominal total fue predominantemente enfermedad médicamente refractaria (77%), con displasia la segunda indicación principal (13%). En un seguimiento medio general de 3 años, 16 pacientes se habían sometido a una proctectomía o a una derivación con el recto in situ. Esto dio como resultado estimaciones de supervivencia sin ostomía a los 5 y 10 años de 78% (intervalo de confianza del 95%: 68-90) y 58% (intervalo de confianza del 95%: 35-94), respectivamente. Un margen microscópico distal positivo fue el único factor de riesgo para el requerimiento posterior de una ileostomía permanente (razón de riesgo: 5.4; intervalo de confianza del 95%, 1.7-17.2).Estudio retrospectivo en un centro de referencia de tercer nivel.La supervivencia a largo plazo sin ostomía se puede lograr en la mayoría de los pacientes que se someten a la restauración de la continuidad intestinal después de la colectomía abdominal total por colitis de Crohn. Un margen microscópico distal positivo se asoció de forma independiente con la insuficiencia anastomótica a largo plazo, y debe tenerse en cuenta cuando se trata de pacientes con estratificación de riesgo para el tratamiento médico profiláctico postoperatorio. Consulte Video Resumen en http://links.lww.com/DCR/B111.

Should We Divide Crohn's Disease Into Ileum-Dominant and Isolated Colonic Diseases?

Crohn's disease (CD) is an inflammatory bowel disease that can involve any region of the gastrointestinal tract. First described in 1932 as terminal ileitis or regional enteritis, it predominately involves the ileum with or without colonic involvement. Isolated colonic CD was first described in 1960 and since then the phenotypic classification of CD has evolved to stratify patients into isolated ileal, ileocolonic, or isolated colonic involvement. In the current review we evaluate the published literature regarding differences in epidemiology, natural history, pathogenesis, response to therapy, and disease monitoring, when stratified by disease location. Based on the available evidence consideration could be given to a new classification for CD, which splits it into ileum dominant (isolated ileal and ileocolonic) and isolated colonic disease. This may allow for a more optimized approach to clinical care and scientific research for CD.

British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults

Ulcerative colitis and Crohn's disease are the principal forms of inflammatory bowel disease. Both represent chronic inflammation of the gastrointestinal tract, which displays heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management relies on understanding and tailoring evidence-based interventions by clinicians in partnership with patients. This guideline for management of inflammatory bowel disease in adults over 16 years of age was developed by Stakeholders representing UK physicians (British Society of Gastroenterology), surgeons (Association of Coloproctology of Great Britain and Ireland), specialist nurses (Royal College of Nursing), paediatricians (British Society of Paediatric Gastroenterology, Hepatology and Nutrition), dietitians (British Dietetic Association), radiologists (British Society of Gastrointestinal and Abdominal Radiology), general practitioners (Primary Care Society for Gastroenterology) and patients (Crohn's and Colitis UK). A systematic review of 88 247 publications and a Delphi consensus process involving 81 multidisciplinary clinicians and patients was undertaken to develop 168 evidence- and expert opinion-based recommendations for pharmacological, non-pharmacological and surgical interventions, as well as optimal service delivery in the management of both ulcerative colitis and Crohn's disease. Comprehensive up-to-date guidance is provided regarding indications for, initiation and monitoring of immunosuppressive therapies, nutrition interventions, pre-, peri- and postoperative management, as well as structure and function of the multidisciplinary team and integration between primary and secondary care. Twenty research priorities to inform future clinical management are presented, alongside objective measurement of priority importance, determined by 2379 electronic survey responses from individuals living with ulcerative colitis and Crohn's disease, including patients, their families and friends.

British Society of Gastroenterology consensus guidelines on the management of inflammatory bowel disease in adults

Ulcerative colitis and Crohn's disease are the principal forms of inflammatory bowel disease. Both represent chronic inflammation of the gastrointestinal tract, which displays heterogeneity in inflammatory and symptomatic burden between patients and within individuals over time. Optimal management relies on understanding and tailoring evidence-based interventions by clinicians in partnership with patients. This guideline for management of inflammatory bowel disease in adults over 16 years of age was developed by Stakeholders representing UK physicians (British Society of Gastroenterology), surgeons (Association of Coloproctology of Great Britain and Ireland), specialist nurses (Royal College of Nursing), paediatricians (British Society of Paediatric Gastroenterology, Hepatology and Nutrition), dietitians (British Dietetic Association), radiologists (British Society of Gastrointestinal and Abdominal Radiology), general practitioners (Primary Care Society for Gastroenterology) and patients (Crohn's and Colitis UK). A systematic review of 88 247 publications and a Delphi consensus process involving 81 multidisciplinary clinicians and patients was undertaken to develop 168 evidence- and expert opinion-based recommendations for pharmacological, non-pharmacological and surgical interventions, as well as optimal service delivery in the management of both ulcerative colitis and Crohn's disease. Comprehensive up-to-date guidance is provided regarding indications for, initiation and monitoring of immunosuppressive therapies, nutrition interventions, pre-, peri- and postoperative management, as well as structure and function of the multidisciplinary team and integration between primary and secondary care. Twenty research priorities to inform future clinical management are presented, alongside objective measurement of priority importance, determined by 2379 electronic survey responses from individuals living with ulcerative colitis and Crohn's disease, including patients, their families and friends.

A nomogram for predicting the response to exclusive enteral nutrition in adult patients with isolated colonic Crohn's disease

BACKGROUND

Isolated colonic Crohn's disease (cCD) responds less well to induction therapy with exclusive enteral nutrition (EEN) compared with ileal or ileocolonic disease in adult patients; therefore, we aimed to identify the factors that influence the response to EEN and develop a predictive nomogram model to optimize the use of EEN in cCD patients.

MATERIALS AND METHODS

Eighty-five cCD patients treated with EEN as first-line therapy at our center between 1 June 2012 and 30 June 2018 were retrospectively analyzed as the primary cohort. The primary endpoint was clinical remission after EEN therapy. Potential predictive factors for the efficacy of EEN were assessed by univariate and multivariate analyses, and a nomogram to predict the response to EEN therapy in cCD patients was designed. Another 19 cCD patients were retrospectively included in the validation cohort to verify the accuracy of the nomogram model.

RESULTS

The clinical remission rates for the primary cohort and validation cohort were 52.9% and 47.4%, respectively. Pancolitis was the greatest contributor to the risk of failure to respond to EEN [odds ratio (OR) = 4.896; 95% confidence interval (CI) = 1.223-19.607; p = 0.025], lean body mass index (LBMI), colonic lesion features, simple endoscopic scores for Crohn's disease, C-reactive protein before treatment and ∆prealbumin were also related to the efficacy of EEN in cCD. The nomogram model showed robust discrimination, with an area under the receiving operating characteristic curve of 0.906.

CONCLUSION

Several predictive factors for response to EEN therapy in cCD adult patients were identified, and a promising nomogram that can predict the effect of EEN in cCD was developed.

Isolated colonic Crohn's disease is associated with a reduced response to exclusive enteral nutrition compared to ileal or ileocolonic disease

BACKGROUND & AIMS

Exclusive enteral nutrition (EEN) as a primary therapy is safe and effective for inducing the clinical remission of active luminal Crohn's disease (CD). Whether isolated colonic involvement affects the efficacy of EEN is controversial. We aimed to identify the influence of isolated colonic CD on the efficacy of EEN and to determine other potential predictors of the response to induction therapy with EEN in adult patients with CD.

METHODS

Data for adult CD patients treated with EEN as an induction therapy at our centre from January 1, 2014, to May 31, 2017, were reviewed. Eligible patients were divided into an isolated colonic Crohn's disease (cCD) group and a non-isolated colonic Crohn's disease (non-cCD) group according to the disease location. The rates of clinical remission and inflammatory and nutritional serum markers were compared between the groups. Possible relationships between isolated colonic involvement or other potential factors and the efficacy of EEN were assessed by univariate and multivariate analyses. The propensity score matching method was used to confirm the results.

RESULTS

Overall, 241 patients were included in the analysis: 52 patients in the cCD group and 189 patients in the non-cCD group. The rates of clinical remission differed between the two groups (cCD group: 51.9% versus non-cCD group: 68.3%, P = 0.029). Multivariate analyses indicated that isolated colonic involvement was associated with a reduced response to EEN (OR = 2.74; [CI] 95% = [1.2-6.23], P = 0.016). Additionally, the lean body mass index (LBMI) before treatment was associated with the efficacy of EEN (OR = 0.636; [CI] 95% = [0.444-0.912], P = 0.014). These associations were confirmed using the propensity score model. For patients with isolated colonic CD, multivariate analysis showed that pancolitis (OR = 16.7; [CI] 95% = [1.074-260.5], P = 0.044) was another independent factor for the efficacy of EEN. Further analysis showed that even in patients who achieved clinical remission after EEN, inflammatory serum markers declined more slowly in the cCD group than in the non-cCD group, and the time to remission was longer in the cCD group.

CONCLUSIONS

Isolated colonic CD showed a reduced response to induction therapy with EEN compared with ileal or ileocolonic disease in adult patients. Patients with isolated colonic CD required more time to benefit from EEN therapy compared with patients with non-colonic CD. Additionally, LBMI before treatment was associated with the efficacy of EEN.

Big data in IBD: a look into the future

Big data methodologies, made possible with the increasing generation and availability of digital data and enhanced analytical capabilities, have produced new insights to improve outcomes in many disciplines. Application of big data in the health-care sector is in its early stages, although the potential for leveraging underutilized data to gain a better understanding of disease and improve quality of care is enormous. Owing to the intrinsic characteristics of inflammatory bowel disease (IBD) and the management dilemmas that it imposes, the implementation of big data research strategies not only can complement current research efforts but also could represent the only way to disentangle the complexity of the disease. In this Review, we explore important potential applications of big data in IBD research, including predictive models of disease course and response to therapy, characterization of disease heterogeneity, drug safety and development, precision medicine and cost-effectiveness of care. We also discuss the strengths and limitations of potential data sources that big data analytics could draw from in the field of IBD, including electronic health records, clinical trial data, e-health applications and genomic, transcriptomic, proteomic, metabolomic and microbiomic data.

Previous colonic resection is a risk factor for surgical relapse in Crohn's disease

BACKGROUND

Despite the improvement of medical therapies, nearly half of patients with Crohn's disease require surgery within 10 years after diagnosis. However, intestinal resection is not curative and recurrence may occur.

AIMS

To evaluate post-surgical outcomes for patients with Crohn's disease in a large monocentric cohort, and to identify variables associated with clinical and surgical relapse.

METHODS

Patients with Crohn's disease who had surgery for ileal and colonic Crohn's disease between 2004 and 2016 and on at least one-year follow-up following surgery were included.

RESULTS

One hundred ninety-three patients were included in the study. Crohn's disease recurrence concerned 53% of patients after a median 56-month (6-158) follow-up and 29% of patients required a second surgical intervention. At logistic regression analysis, active smoking and young age at diagnosis were identified as independent risk factor for post-surgical relapse (p = 0.01), while colonic or ileocolonic resection was recognized as a risk factor for surgical Crohn's disease relapse (p = 0.003).

CONCLUSIONS

Post-surgery recurrence is frequent for patients with Crohn's disease. Active smoking and young age at diagnosis are risk factors for Crohn's disease recurrence. As compared with patients undergoing small-bowel surgery, patients with colonic resection are proner to relapse requiring a second surgical intervention.

Application of Proteomics to Inflammatory Bowel Disease Research: Current Status and Future Perspectives

Inflammatory bowel disease (IBD) is a chronic relapsing/remitting inflammatory illness of the gastrointestinal tract of unknown aetiology. Despite recent advances in decoding the pathophysiology of IBD, many questions regarding disease pathogenesis remain. Genome-wide association studies (GWAS) and knockout mouse models have significantly advanced our understanding of genetic susceptibility loci and inflammatory pathways involved in IBD pathogenesis. Despite their important contribution to a better delineation of the disease process in IBD, these genetic findings have had little clinical impact to date. This is because the presence of a given gene mutation does not automatically correspond to changes in its expression or final metabolic or structural effect(s). Furthermore, the existence of these gene susceptibility loci in the normal population suggests other driving prerequisites for the disease manifestation. Proteins can be considered the main functional units as almost all intracellular physiological functions as well as intercellular interactions are dependent on them. Proteomics provides methods for the large-scale study of the proteins encoded by the genome of an organism or a cell, to directly investigate the proteins and pathways involved. Understanding the proteome composition and alterations yields insights into IBD pathogenesis as well as identifying potential biomarkers of disease activity, mucosal healing, and cancer progression. This review describes the state of the art in the field with respect to the study of IBD and the potential for translation from biomarker discovery to clinical application.

T-cell Composition in Ileal and Colonic Creeping Fat - Separating Ileal from Colonic Crohn's Disease

BACKGROUND AND AIMS

Creeping fat [CF] is a hyperplasia of adipose tissue adjacent to inflamed intestine in Crohn's disease [CD]. Data from genome-wide association studies [GWAS] distinguished Crohn's colitis from ileal CD and ulcerative colitis [UC]. This study analysed the T-cell compartments of ileal and colonic mesenteric fat and corresponding mucosa to provide cellular proof for the suggested GWAS classification.

METHODS

Samples were obtained from 34 CD or UC patients. Cells were analysed by immunohistochemistry and flow cytometry, and tissue cytokine release was assessed by cytometric bead array.

RESULTS

Only ileal CF revealed the distinct adipocyte hyperplasia combined with dense T-cell infiltration and fibrosis; colonic fat from CD and UC patients lacked these findings. T-cell subpopulations differed between mesenteric fat in ileal CD, colonic CD and UC: ileal CF had nearly 10 times more T-cells than colonic fat. The proportions of regulatory and central memory T-cells were significantly higher in ileal CF compared with colonic fat in CD and UC. In all groups, the mucosal T-cell compartment was distinct from the mesenteric fat. Remarkably, correlation between disease activity and proportion of pro- and anti-inflammatory T-cell subpopulations was inverse, comparing ileal and colonic fat in CD.

CONCLUSIONS

This first in-depth analysis of the T-cell compartment in ileal and colonic mesenteric adipose tissue in CD and UC identifies a unique T-cell niche in the ileal mesenteric fat tissue in CD. From a clinical point of view, our findings underscore the novel concept of colonic and ileal CD as distinct IBD entities.

Altered uric acid metabolism in isolated colonic Crohn's disease but not ulcerative colitis

BACKGROUND AND AIM

Patients with inflammatory bowel disease (IBD) have higher incidence of developing nephrolithiasis. Increased uric acid production induced by Saccharomyces cerevisiae exacerbates colitis in mice. We aimed to evaluate the association between serum uric acid level and disease activity in IBD population.

METHODS

Four hundred and thirty-five patients enrolled in Jinling Hospital from January 1, 2015 to August 31, 2017 were included in the retrospective study. Clinical parameters were collected and compared with non-IBD matched controls (n = 51). Serum uric acid to creatinine ratio (UA/Cr) was used as a biomarker for uric acid metabolism. Sixty-five active IBD patients were longitudinally studied to investigate the UA/Cr before and after therapy. Linear mixed models were estimated for Crohn's disease (CD) group to explore the relationship between UA/Cr and other parameters.

RESULTS

Uric acid to creatinine ratio was significantly correlated with Crohn's disease activity index (ρ = 0.184, P = 0.002) and Harvey Bradshaw index (ρ = 0.154, P = 0.010) and C-reactive protein (ρ = 0.591, P < 0.001) in CD group. Colonic CD and anti-Saccharomyces cerevisiae antibody (ASCA) positive CD had an increased UA/Cr compared with L1, L3, and ASCA negative CD (P = 0.027, P = 0.0013, and P = 0.043, respectively). A significant decrease in UA/Cr was observed after induction therapy in active CD (P = 0.0002) but not in ulcerative colitis (P = 0.076).

CONCLUSION

Uric acid to creatinine ratio correlated with disease activity in CD. Colonic CD and ASCA positive CD had an increased UA/Cr. Effective treatment for CD patients lowered UA/Cr. Uric acid metabolism might be a novel aspect to investigate disease activity of IBD.

MicroRNA-590-5p Inhibits Intestinal Inflammation by Targeting YAP

BACKGROUND AND AIMS

Hippo signalling is an evolutionarily conserved pathway that controls organ size by regulating cell proliferation, survival, apoptosis, and stem cell self-renewal. In addition, Hippo signalling is profoundly implicated in intestinal regeneration and cancer. However, its roles in the pathogenesis of Crohn's disease [CD] remain largely unexplored.

METHODS

Quantitative reverse transcription-polymerase chain reaction [qRT-PCR] was performed to identify the deregulated molecules in Hippo signalling. Expression of the highly upregulated Yes-associated protein 1 [YAP] was subsequently examined by qRT-PCR, western blotting, and immunohistochemistry in the intestinal tissues of CD patients and the colons of 2,4,6-trinitrobenzene sulphonic acid [TNBS]-induced colitis mice. The microRNAs [miRNAs] predicted to target YAP were explored by transfection of miR-590-5p mimics or inhibitors and analyzed by luciferase reporter assay. The roles of the miR-590-5p/YAP axis in CD and colorectal cancer were studied in experimental colitis mice and colorectal cancer cell lines.

RESULTS

YAP mRNA was significantly upregulated in intestinal epithelial cells in CD patients and TNBS-induced colitis mice. MiR-590-5p suppressed YAP expression by directly targeting the YAP 3'-untranslated region in Caco-2 cells and SW620 cells. Upregulation of miR-590-5p in colon reduced YAP level and its downstream targets in intestinal epithelial cells [IECs]. Treatment of miR-590-5p or YAP inhibitor Verteporfin alleviated experimental colitis. Targeting the miR-590-5p/YAP axis inhibited cell proliferation and invasiveness of colorectal cancer [CRC] cells in vitro.

CONCLUSIONS

Our results suggest that miR-590-5p inhibits intestinal inflammation in mouse colon and tumourigenesis of colorectal cancer cells by inhibiting YAP. The miR-590-5p/YAP axis may be an important novel mechanism in the pathogenesis of CD and colorectal cancer.

Subphenotypes of inflammatory bowel disease are characterized by specific serum protein profiles

OBJECTIVE

Genetic and immunological data indicate that inflammatory bowel disease (IBD) are characterized by specific inflammatory protein profiles. However, the serum proteome of IBD is still to be defined. We aimed to characterize the inflammatory serum protein profiles of Crohn's disease (CD) and ulcerative colitis (UC), using the novel proximity extension assay.

METHODS

A panel of 91 inflammatory proteins were quantified in a discovery cohort of CD (n = 54), UC patients (n = 54), and healthy controls (HCs; n = 54). We performed univariate analyses by t-test, with false discovery rate correction. A sparse partial least-squares (sPLS) approach was used to identify additional discriminative proteins. The results were validated in a replication cohort.

RESULTS

By univariate analysis, 17 proteins were identified with significantly different abundances in CD and HCs, and 12 when comparing UC and HCs. Additionally, 64 and 45 discriminant candidate proteins, respectively, were identified with the multivariate approach. Correspondingly, significant cross-validation error rates of 0.12 and 0.19 were observed in the discovery cohort. Only FGF-19 was identified from univariate comparisons of CD and UC, but 37 additional discriminant candidates were identified using the multivariate approach. The observed cross-validation error rate for CD vs. UC remained significant when restricting the analyses to patients in clinical remission. Using univariate comparisons, 16 of 17 CD-associated proteins and 8 of 12 UC-associated proteins were validated in the replication cohort. The area under the curve for CD and UC was 0.96 and 0.92, respectively, when the sPLS model from the discovery cohort was applied to the replication cohort.

CONCLUSIONS

By using the novel PEA method and a panel of inflammatory proteins, we identified proteins with significantly different quantities in CD patients and UC patients compared to HCs. Our data highlight the potential of the serum IBD proteome as a source for identification of future diagnostic biomarkers.

Development and Validation of Diagnostic Criteria for IBD Subtypes Including IBD-unclassified in Children: a Multicentre Study From the Pediatric IBD Porto Group of ESPGHAN

BACKGROUND

The revised Porto criteria identify subtypes of paediatric inflammatory bowel diseases: ulcerative colitis [UC], atypical UC, inflammatory bowel disease unclassified [IBDU], and Crohn's disease [CD]. Others have proposed another subclassifiction of Crohn's colitis. In continuation of the Porto criteria, we aimed to derive and validate criteria, termed "PIBD-classes," for standardising the classification of the different IBD subtypes.

METHODS

This was a multicentre retrospective longitudinal study from 23 centres affiliated with the Port -group of ESPGHAN. Both a hypothesis-driven judgmental approach and mathematical classification and regression tree [CART] modelling were used for creating a diagnostic algorithm. Since small bowel inflammation is easily recognised as CD, we focused here primarily on the phenotype of colitis.

RESULTS

In all, 749 IBD children were enrolled: 236 [32%] Crohn's colitis, 272 [36%] UC and 241 [32%] IBDU [age 10.9 ± 3.6 years] with a median follow-up of 2.8 years (interquartile range [IQR] 1.7-4.3). A total of 23 features were clustered in three classes according to their prevalence in UC: six class-1 features [0% prevalence in UC], 12 class-2 features [< 5% prevalence], and five class-3 features [5-10% prevalence]. According to the algorithm, the disease should be classified as UC if no features exist in any of the classes. When at least one feature exists, different combinations classify the disease into atypical UC, IBDU or CD. The algorithm differentiated UC from CD and IBDU with 80% sensitivity (95% confidence interval [CI] 71-88%) and 84% specificity [77-89%], and CD from IBDU and UC with 78% sensitivity [67-87%] and 94% specificity [89-97%].

CONCLUSIONS

The validated PIBD-classes algorithm can adequately classify children with IBD into small bowel CD, colonic CD, IBDU, atypical UC, and UC.

Caffeic acid phenethyl ester is protective in experimental ulcerative colitis via reduction in levels of pro-inflammatory mediators and enhancement of epithelial barrier function

Background

Inhibition of the nuclear factor kappa beta (NF-κβ) pathway has been proposed as a therapeutic target due to its key role in the expression of pro-inflammatory genes, including pro-inflammatory cytokines, chemokines, and adhesion molecules. Caffeic acid phenethyl ester (CAPE) is a naturally occurring anti-inflammatory agent, found in propolis, and has been reported as a specific inhibitor of NF-κβ. However, the impact of CAPE on levels of myeloperoxidases (MPO) and pro-inflammatory cytokines during inflammation is not clear. The aims of this study were to investigate the protective efficacy of CAPE in the mouse model of colitis and determine its effect on MPO activity, pro-inflammatory cytokines levels, and intestinal permeability.

Method

Dextran sulphate sodium was administered in drinking water to induce colitis in C57/BL6 mice before treatment with intraperitoneal administration of CAPE (30 mg kg⁻¹ day⁻¹). Disease activity index (DAI) score, colon length and tissue histology levels of MPO, pro-inflammatory cytokines, and intestinal permeability were observed.

Results

CAPE-treated mice had lower DAI and tissue inflammation scores, with improved epithelial barrier protection and significant reduction in the level of MPO and pro-inflammatory cytokines.

Conclusion

Our results show that CAPE is effective in suppressing inflammation-triggered MPO activity and pro-inflammatory cytokines production while enhancing epithelial barrier function in experimental colitis. Thus, we conclude that CAPE could be a potential therapeutic agent for further clinical investigations for treatment of inflammatory bowel diseases in humans.

Electronic supplementary material

The online version of this article (doi:10.1007/s10787-017-0364-x) contains supplementary material, which is available to authorized users.

Inflammatory Bowel Disease-Unclassified in Children: Diagnosis and Pharmacological Management

Inflammatory bowel diseases are chronic disorders of the gastrointestinal tract that include Crohn's disease (CD), ulcerative colitis (UC) and inflammatory bowel disease-unclassified (IBDU). The latter defines a subgroup of patients with clinical and endoscopic evidence of chronic colitis, without specific features of either CD or UC. These patients will possibly be re-classified as having UC or CD during the follow-up, although a significant percentage of them will keep the diagnosis of IBDU. IBDU is the rarest subtype of IBD, both in children and in adults, although it is twice as common among the pediatric population, especially in the younger ages. The diagnosis can only be made after a comprehensive diagnostic work-up, combining clinical history, physical and laboratory examination, upper and lower gastrointestinal endoscopy, with histology and imaging of the small bowel. The therapeutic strategy is borrowed from that of UC and CD, although recent data suggest that IBDU has a lower therapeutic burden with a generally mild disease course and a good response to mesalamine. Since there are only few published data on pediatric IBDU, and no guidelines on its management are available, this review aims at summarizing the most recent evidence for the diagnostic work-up with a specific focus on medical and surgical options in the treatment of IBDU.