Fecal Microbiota Transplantation Outcome and Gut Microbiota Composition in Ulcerative Colitis: a Systematic Review and Meta-analysis.

BACKGROUND & AIMS: Fecal microbiota transplantation (FMT) can induce remission in patients with ulcerative colitis (UC), yet its efficacy needs improvement. We conducted a comprehensive evaluation of the current literature on microbial factors affecting outcome, as well as a meta-analysis on some of the largest datasets regarding composition. METHODS: MEDLINE, Embase and Cochrane were systematically searched through August 2024 for relevant studies. The quality of studies was analyzed with Joanna Briggs tools and a composite critical appraisal-score. Additionally, species-level data from two landmark FMT-trials (TURN and FOCUS) were re-analyzed from a compositional perspective. RESULTS: Out of 3755 citations identified, 56 met the inclusion criteria, of which 29 fulfilled quality standards. Higher microbial α-diversity, either in donors or recipients (at baseline or following FMT treatment), was associated with better clinical response rates. Engraftment of the donors' microbiota could not be clearly linked with clinical response, possibly because not every donor has an ideal microbiome. Butyrate producing species from the Lachnospiraceae and Oscillospiraceae families were often related with response, whereas the reverse was true for Fusobacteria, many Proteobacteria and Ruminococcus gnavus. Compositional analyses showed that clinical response is associated with a shift from a low-diversity, often Bacteroides dominant composition to one with higher diversity, either dominated by various butyrate producers, the Christensenellaceae-Methanobrevibacter trophic network, or a moderate/high diversity composition with abundant but not excessive levels of Prevotella copri. CONCLUSION: This systematic review/meta-analysis yielded a coherent picture from a compositional perspective, which may help identify beneficial donor profiles and guide personalized FMT approaches.

Long-term outcomes after close rectal dissection and total mesorectal excision in ileal pouch-anal anastomosis for ulcerative colitis.

BACKGROUND: During ileal pouch-anal anastomosis (IPAA) surgery for ulcerative colitis (UC), rectal dissection can be performed via close rectal dissection (CRD) or in a total mesorectal excision plane (TME). Although CRD should protect autonomic nerve function, this technique may be more challenging than TME. The aim of this study was to compare long-term outcomes of patients undergoing CRD and TME. METHODS: This single-centre retrospective cohort study included consecutive patients who underwent IPAA surgery for UC between January 2002 and October 2017. Primary outcomes were chronic pouch failure (PF) among patients who underwent CRD and TME and the association between CRD and developing chronic PF. Chronic PF was defined as a pouch-related complication occurring ≥ 3 months after primary IPAA surgery requiring redo pouch surgery, pouch excision or permanent defunctioning ileostomy. Secondary outcomes were risk factors and causes for chronic PF. Pouch function and quality of life were assessed via the Pouch dysfunction score and Cleveland global quality of life score. RESULTS: Out of 289 patients (155 males, median age 37 years [interquartile range 26.5-45.5 years]), 128 underwent CRD. There was a shorter median postoperative follow-up for CRD patients than for TME patients (3.7 vs 10.9 years, p < 0.01). Chronic PF occurred in 6 (4.7%) CRD patients and 20 (12.4%) TME patients. The failure-free pouch survival rate 3 years after IPAA surgery was comparable among CRD and TME patients (96.1% vs. 93.5%, p = 0.5). CRD was a no predictor for developing chronic PF on univariate analyses (HR 0.7 CI-95 0.3-2.0, p = 0.54). A lower proportion of CRD patients developed chronic PF due to a septic cause (1% vs 6%, p = 0.03). CONCLUSIONS: Although differences in chronic PF among CRD and TME patients were not observed, a trend toward TME patients developing chronic pelvic sepsis was detected. Surgeons may consider performing CRD during IPAA surgery for UC.

ImmUniverse Consortium: Multi-omics integrative approach in personalized medicine for immune-mediated inflammatory diseases.

Immune mediated inflammatory diseases (IMIDs) are a heterogeneous group of debilitating, multifactorial and unrelated conditions featured by a dysregulated immune response leading to destructive chronic inflammation. The immune dysregulation can affect various organ systems: gut (e.g., inflammatory bowel disease), joints (e.g., rheumatoid arthritis), skin (e.g., psoriasis, atopic dermatitis), resulting in significant morbidity, reduced quality of life, increased risk for comorbidities, and premature death. As there are no reliable disease progression and therapy response biomarkers currently available, it is very hard to predict how the disease will develop and which treatments will be effective in a given patient. In addition, a considerable proportion of patients do not respond sufficiently to the treatment. ImmUniverse is a large collaborative consortium of 27 partners funded by the Innovative Medicine Initiative (IMI), which is sponsored by the European Union (Horizon 2020) and in-kind contributions of participating pharmaceutical companies within the European Federation of Pharmaceutical Industries and Associations (EFPIA). ImmUniverse aims to advance our understanding of the molecular mechanisms underlying two immune-mediated diseases, ulcerative colitis (UC) and atopic dermatitis (AD), by pursuing an integrative multi-omics approach. As a consequence of the heterogeneity among IMIDs patients, a comprehensive, evidence-based identification of novel biomarkers is necessary to enable appropriate patient stratification that would account for the inter-individual differences in disease severity, drug efficacy, side effects or prognosis. This would guide clinicians in the management of patients and represent a major step towards personalized medicine. ImmUniverse will combine the existing and novel advanced technologies, including multi-omics, to characterize both the tissue microenvironment and blood. This comprehensive, systems biology-oriented approach will allow for identification and validation of tissue and circulating biomarker signatures as well as mechanistic principles, which will provide information about disease severity and future disease progression. This truly makes the ImmUniverse Consortium an unparalleled approach.

Hyperbaric oxygen therapy for the treatment of rectovaginal fistulas in patients with Crohn's disease: results of the HOT-REVA pilot study.

BACKGROUND: Positive effects of hyperbaric oxygen (HBO) on perianal fistulas in Crohn's disease (CD) have been described, but the effect on rectovaginal fistulas (RVFs) has not yet been studied. The aim was to investigate the efficacy, safety and feasibility of HBO in patients with RVF in CD. METHODS: In this prospective study, consecutive CD patients between November 2018 and February 2020 presenting with RVF at the outpatient fistula clinic of the Amsterdam University Medical Centre were included and selected to receive treatment with 30 daily HBO sessions, if fistulas were actively draining and any concomitant treatment regimen was stable at least 6 weeks prior to start of HBO. Patients with a stoma were excluded. The primary endpoint was clinical closure at 3-month follow-up, defined as cessation of complaints and/or closure of the external orifice if visible at baseline. Secondary outcomes were improvement of concomitant perianal fistulas as measured by the perianal disease activity index (PDAI) and fistula drainage assessment (FDA), as well as improvement in patient-reported outcomes (visual analogue scale (VAS), inflammatory bowel disease questionnaire (IBDQ), faecal incontinence quality of life scale (FIQL) and female sexual functioning index (FSFI)) at 3-month follow-up. RESULTS: Out of 14 eligible patients, nine patients (median age 50 years) were treated, all of whom had previously had one or more unsuccessful medical and/or surgical treatments for their RVF. Clinical closure occurred in none of the patients at 3-month follow-up. There was no improvement in PDAI and patient-reported outcomes (VAS, IBDQ, FIQL and FSFI). Two patients had concomitant perianal fistulas; using FDA, one patient had a clinical response and one patient was in clinical remission 3 months after HBO. There were two treatment-related adverse events during HBO concerning claustrophobia and fatigue. Furthermore, two patients had a surgical intervention due to RVF and two patients were treated with antibiotics for a urinary tract infection during follow-up. One patient had a dose reduction of ustekinumab because of decreased luminal complaints. CONCLUSION: Treatment with HBO was feasible, but in this therapy-refractory cohort without deviating ostomy no clinical closure of RVF or improvement in quality of life was seen 3 months after HBO. Treatment with HBO alone in this specific group of patients therefore appears to be ineffective.

A nationwide database study on colectomy and colorectal cancer in ulcerative colitis: what is the role of appendectomy?

AIM: Although has been suggested that an appendectomy has a positive effect on the disease course in patients with ulcerative colitis (UC), recent studies indicate a potential increase in risk of colectomy and colorectal cancer (CRC). This study aimed to evaluate the rates of colectomy and CRC after appendectomy in UC patients using a nationwide prospective database [the Initiative on Crohn and Colitis Parelsnoer Institute - Inflammatory Bowel Disease (ICC PSI-IBD) database]. METHOD: All UC patients were retrieved from the ICC PSI-IBD database between January 2007 and May 2018. Primary outcomes were colectomy and CRC. Outcomes were compared in patients with and without appendectomy, with a separate analysis for timing of appendectomy (before or after UC diagnosis). RESULTS: A total of 826 UC patients (54.7% female; median age 46 years, range 18-89 years) were included. Sixty-three (7.6%) patients had previously undergone appendectomy: 24 (38.1%) before and 33 (52.4%) after their diagnosis of UC. In multivariate analysis, appendectomy after UC diagnosis was associated with a significantly lower colectomy rate compared with no appendectomy [hazard ratio (HR) 0.16, 95% C: 0.04-0.66, P = 0.011], and the same nonsignificant trend was seen in patients with an appendectomy before UC diagnosis (HR 0.35, 95% CI 0.08-1.41, P = 0.138). Appendectomy was associated with delayed colectomy, particularly when it was performed after diagnosis of UC (P = 0.009). No significant differences were found in the CRC rate between patients with and without appendectomy (1.6% vs 1.2%; P = 0.555). CONCLUSION: Appendectomy in established UC is associated with an 84% decreased risk of colectomy and a delay in surgery. Since the colon is in situ for longer, the risk of developing CRC remains, which underscores the importance of endoscopic surveillance programmes.

Systematic Review: Histological Scoring of Strictures in Crohn's Disease.

BACKGROUND AND AIMS: In Crohn's disease, many patients develop a stricture, which can due to inflammation, fibrosis and muscular changes or all at the same time. Determining the predominant component has therapeutic consequences but remains challenging. To develop imaging techniques that assess the nature of a stricture, a gold standard is needed and histopathology is considered as such. This paper provides an overview of published histological scoring systems for strictures in Crohn's disease. METHODS: A systematic literature review according to PRISMA guidelines was performed of histological scoring indices that assessed whether a stricture was inflammation-predominant or fibrosis-predominant. Multiple libraries were searched from inception to December 2018. Two reviewers independently assessed abstracts and full-texts. RESULTS: Sixteen articles were identified as suitable for this systematic review. A large number of parameters were reported. Extent of neutrophil infiltration and extent of fibrosis in the bowel wall were most frequently described to reflect severity of inflammation and fibrosis, respectively. Among the 16 studies, only two described a numerical scoring system for the inflammatory and fibrotic component separately. Smooth muscle changes were scored in a minority of studies. CONCLUSIONS: Multiple scoring systems have been developed. There was large heterogeneity in scoring per parameter and construction of numerical scoring systems. Therefore, we feel that none of the systems is suitable to be used as gold standard. We offer an overview of histological parameters that could be incorporated in a future histological scoring index for strictures.

Prospective cohort study of appendicectomy for treatment of therapy-refractory ulcerative colitis.

INTRODUCTION: Appendicectomy may reduce relapses and need for medication in patients with ulcerative colitis, but long-term prospective data are lacking. This study aimed to analyse the effect of appendicectomy in patients with refractory ulcerative colitis. METHODS: In this prospective multicentre cohort series, all consecutive patients with refractory ulcerative colitis referred for proctocolectomy between November 2012 and June 2015 were counselled to undergo laparoscopic appendicectomy instead. The primary endpoint was clinical response (reduction of at least 3 points in the partial Mayo score) at 12 months and long-term follow-up. Secondary endpoints included endoscopic remission (endoscopic Mayo score of 1 or less), failure (colectomy or start of experimental medication), and changes in Inflammatory Bowel Disease Questionnaire (IBDQ) (range 32-224), EQ-5D™ and EORTC-QLQ-C30-QL scores. RESULTS: A total of 28 patients (13 women; median age 40·5 years) underwent appendicectomy. The mean baseline IBDQ score was 127·0, the EQ-5D™ score was 0·65, and the EORTC-QLQ-C30-QL score was 41·1. At 12 months, 13 patients had a clinical response, five were in endoscopic remission, and nine required a colectomy (6 patients) or started new experimental medical therapy (3). IBDQ, EQ-5D™ and EORTC-QLQ-C30-QL scores improved to 167·1 (P < 0·001), 0·80 (P = 0·003) and 61·0 (P < 0·001) respectively. After a median of 3·7 (range 2·3-5·2) years, a further four patients required a colectomy (2) or new experimental medical therapy (2). Thirteen patients had a clinical response and seven were in endoscopic remission. The improvement in IBDQ, EQ-5D™ and the EORTC-QLQ-C30-QL scores remained stable over time. CONCLUSION: Appendicectomy resulted in a clinical response in nearly half of patients with refractory ulcerative colitis and a substantial proportion were in endoscopic remission. Elective appendicectomy should be considered before proctocolectomy in patients with therapy-refractory ulcerative colitis.

ANTECEDENTES: La apendicectomía puede reducir las recaídas y la necesidad de medicación en pacientes con colitis ulcerosa (ulcerative colitis, UC), sin embargo, faltan datos a largo plazo obtenidos de forma prospectiva. El objetivo de este estudio fue analizar el efecto de la apendicectomía en pacientes con UC refractarios al tratamiento. MÉTODOS: En esta serie prospectiva de cohortes multicéntrica, a todos los pacientes consecutivos con UC refractaria remitidos para proctocolectomía entre noviembre de 2012 y junio de 2015 se les recomendó en su lugar someterse a una apendicectomía laparoscópica. El criterio de valoración principal fue la respuesta clínica (disminución de ≥ 3 puntos del sistema de puntuación parcial de Mayo que varía de 0 a 9) a los 12 meses y en el seguimiento a largo plazo. Los criterios de valoración secundarios incluyeron la remisión endoscópica (puntuación endoscópica de Mayo ≤ 1), fracaso (colectomía o inicio de medicación experimental) y cambios en el IBDQ (rango 32-224), EQ-5D y EORTC-QLQ-C30-QL. RESULTADOS: En total, 28 pacientes (13 mujeres, mediana de edad 40,5) se sometieron a una apendicectomía. El IBDQ de referencia promedio fue de 127,0; el EQ-5D 0,65 y el EORTC-QLQ-C30-QL 41,1. A los 12 meses, 13 pacientes presentaban una respuesta clínica, cinco estaban en remisión endoscópica y nueve precisaron colectomía (n = 6) o un nuevo tratamiento médico experimental (n = 3). El IBDQ, EQ-5D y EORTC-QLQ-C30-QL mejoraron a 167,1 (P < 0,001); 0,80 (P = 0,003) y 61,0 (P < 0,001) respectivamente. Después de una mediana de 3,7 años (rango 2,3-5,2), otros cuatro pacientes requirieron una colectomía (n = 2) o un nuevo tratamiento médico experimental (n = 2). Trece pacientes presentaron respuesta clínica y siete se encontraban en remisión endoscópica. La mejora del IBDQ, el EQ-5D y el EORTC-QLQ-C30-QL se mantuvo estable a lo largo del tiempo. CONCLUSIÓN: La apendicectomía consiguió una respuesta clínica en casi la mitad de los pacientes con UC refractaria. La apendicectomía electiva debería ser considerada antes que la proctocolectomía en pacientes con UC refractaria al tratamiento.

Hyperbaric oxygen therapy for the treatment of perianal fistulas in Crohn's disease (HOT-TOPIC): study protocol of a prospective interventional cohort study with one-year follow-up.

Background: Perianal fistulizing Crohn's disease (pCD) has a significant impact on patients' health and quality of life. Current treatment options have a relatively low success rate and a high recurrence risk. Positive effects of hyperbaric oxygen (HBO2) therapy have been indicated in animal studies as well as in small case series. Methods/Design: This is a non-randomized, controlled pilot study. A total of 20 patients with pCD who have been refractory to standard therapy for at least six months will be included. Patients with a seton and stable treatment regimen will be included. Patients with anal strictures, rectovaginal fistulas, stoma or deep ulceration of the rectum will be excluded. Patients who are eligible but refuse HBO2 will be asked to serve as controls. Patients in the HBO2 group will be treated with 40 sessions of HBO2 therapy at 243-253 kPa, with the seton being removed after 30 sessions. Co-primary endpoints are changes in the perianal disease activity index and MRI-scores. Secondary outcomes are fistula drainage assessment, laboratory findings and patient-reported outcomes. Assessment will be done at baseline, 16 weeks, 34 weeks and 60 weeks after finishing HBO2. Discussion: The aim of this study is to investigate the feasibility and therapeutic effect of HBO2 on pCD. The one-year follow-up should provide information on the effect durability. A comparison between patients treated with HBO2 and patients who continue to receive standard care will be made. The risk of bias will be limited by using clearly defined inclusion and exclusion criteria, baseline characteristics and consecutive recruitment of patients through an outpatient fistula clinic. Trial registration: The HOT-TOPIC trial has been approved by the local Medical Ethical Committee of the Academic Medical Centre in Amsterdam, the Netherlands. The trial has been registered at the Netherlands Trial Register (www.trialregister.nl), registration number: NTR 6676. Protocol version: August 2017, version 3.0.

A JAK1 Selective Kinase Inhibitor and Tofacitinib Affect Macrophage Activation and Function.

BACKGROUND: Janus kinases (JAKs) mediate cytokine signaling involved in inflammatory bowel disease. The pan-JAK inhibitor tofacitinib has shown efficacy in the treatment of ulcerative colitis. However, concerns regarding adverse events due to their wide spectrum inhibition fueled efforts to develop selective JAK inhibitors. Given the crucial role of myeloid cells in intestinal immune homeostasis, we evaluated the effect of pan-JAK and selective JAK inhibitors on pro- and anti-inflammatory macrophage polarization and function (M1/M2) and in experimental colitis. METHODS: Murine bone marrow-derived macrophages or human monocytes were treated using JAK1 and JAK3 selective inhibitors (JAK1i;JAK3i) and tofacitinib and were evaluated by transcriptional, functional, and metabolic analyses. In vivo, oral administration of JAK1i and tofacitinib (10 or 30 mg/kg) was tested in both acute and acute rescue dextran sodium sulfate (DSS) colitis. RESULTS: Both tofacitinib and JAK1i but not JAK3i effectively inhibited STAT1 phosphorylation and interferon gamma-induced transcripts in M1 polarized macrophages. Strikingly, transcriptional profiling suggested a switch from M1 to M2 type macrophages, which was supported by increased protein expression of M2-associated markers. In addition, both inhibitors enhanced oxidative phosphorylation rates. In vivo, JAK1i and tofacitinib did not protect mice from acute DSS-induced colitis but ameliorated recovery from weight loss and disease activity during acute rescue DSS-induced colitis at the highest dose. CONCLUSION: JAK1i and tofacitinib but not JAK3i induce phenotypical and functional characteristics of anti-inflammatory macrophages, suggesting JAK1 as the main effector pathway for tofacitinib in these cells. In vivo, JAK1i and tofacitinib modestly affect acute rescue DSS-induced colitis.

Appendectomy for Therapy-Refractory Ulcerative Colitis Results in Pathological Improvement of Colonic Inflammation: Short-Term Results of the PASSION Study.

BACKGROUND AND AIMS: The objective of this study was to examine the modulating effect of an appendectomy on the disease course of therapy-refractory ulcerative colitis [UC] patients, and to analyse appendiceal pathological characteristics predictive of pathological response. METHODS: Patients with therapy-refractory UC, and referred for proctocolectomy, were invited to undergo laparoscopic appendectomy first. The primary end points were clinical response after 3 and 12 months. Secondary end points were endoscopic remission, failure, and pathologic response. Appendiceal specimens, and pre- and post-operative biopsies were histologically graded according to the validated Geboes score. RESULTS: Thirty patients [53% male] with a median age of 40 (interquartile range [IQR], 33-47) underwent appendectomy, with a median preoperative total Mayo score of 9 [IQR, 8-11]. After 12 months, 9 patients [30%] had lasting clinical response, of whom 5 [17%] were in endoscopic remission. Pathological evaluation was possible in 28 patients. After a median of 13.0 weeks [range 7-51], pathological response was seen in 13 patients [46%], with a median decrease of 2 points [range 1-3]. Appendiceal inflammation was highly predictive of pathological response when compared with no inflammation or extensive ulcerations [85% vs 20%, p = 0.001]. CONCLUSIONS: Appendectomy was effective in one-third of therapy-refractory UC patients, with a substantial proportion of patients demonstrating complete endoscopic remission after 1 year. Pathological response was seen in almost 50% of patients and was related to active inflammation in the appendix, limited disease, and shorter disease duration. These early results suggest that there is a UC patient group that may benefit from appendectomy.

Reliability of histologic assessment in patients with eosinophilic oesophagitis.

BACKGROUND: The validity of the eosinophilic oesophagitis (EoE) histologic scoring system (EoEHSS) has been demonstrated, but only preliminary reliability data exist. AIM: Formally assess the reliability of the EoEHSS and additional histologic features. METHODS: Four expert gastrointestinal pathologists independently reviewed slides from adult patients with EoE (N = 45) twice, in random order, using standardised training materials and scoring conventions for the EoEHSS and additional histologic features agreed upon during a modified Delphi process. Intra- and inter-rater reliability for scoring the EoEHSS, a visual analogue scale (VAS) of overall histopathologic disease severity, and additional histologic features were assessed using intra-class correlation coefficients (ICCs). RESULTS: Almost perfect intra-rater reliability was observed for the composite EoEHSS scores and the VAS. Inter-rater reliability was also almost perfect for the composite EoEHSS scores and substantial for the VAS. Of the EoEHSS items, eosinophilic inflammation was associated with the highest ICC estimates and consistent with almost perfect intra- and inter-rater reliability. With the exception of dyskeratotic epithelial cells and surface epithelial alteration, ICC estimates for the remaining EoEHSS items were above the benchmarks for substantial intra-rater, and moderate inter-rater reliability. Estimation of peak eosinophil count and number of lamina propria eosinophils were associated with the highest ICC estimates among the exploratory items. CONCLUSION: The composite EoEHSS and most component items are associated with substantial reliability when assessed by central pathologists. Future studies should assess responsiveness of the score to change after a therapeutic intervention to facilitate its use in clinical trials.

Patterns of anti-TNF use and associated treatment outcomes in inflammatory bowel disease patients: results from an analysis of Dutch health insurance claims data.

INTRODUCTION: Real-life patterns of anti-tumour necrosis factor (anti-TNF) use remain largely unknown. We aimed to investigate survival rates, clinical outcomes and costs of anti-TNF agents in a large population of patients with inflammatory bowel disease (IBD). METHODS: Health insurance data from 22,082 IBD patients were provided by Achmea Healthcare. Time to anti-TNF discontinuation, treatment intensification, corticosteroid initiation and hospitalisation were analysed in patients starting on anti-TNF treatment from January 2008 until December 2014. Treatment regimens were analysed at different time points. RESULTS: In this cohort, 855 and 1199 subjects started infliximab and adalimumab treatment, respectively. The median time to anti-TNF discontinuation was 600 days (IQR 156-1693). The proportion of subjects receiving intensified treatment increased over time (infliximab at 3 vs. 24 months: 22.2% vs. 33.6%, p = 0.01; adalimumab at 3 vs. 24 months: 10.5% vs. 19.3%, p < 0.001). Cessation of anti-TNF treatment was less common in Crohn's disease patients (HR 0.79, p = 0.001) and in patients receiving intensified treatment (HR 0.62, p = 0.001). Immunomodulator use was associated with a longer time to corticosteroid initiation (HR 0.80, p = 0.048), but not with longer drug survival (HR 0.99, p = 0.617). Hospitalisation was more common in Crohn's patients (HR 1.49, p = 0.011). Corticosteroid initiation was lower in Crohn's patients (HR 0.57, p < 0.001) and in patients using infliximab (HR 0.55, p < 0.001). CONCLUSIONS: Discontinuation of anti-TNF therapy occurred earlier than previously reported and was associated with a diagnosis of ulcerative colitis and non-intensified anti-TNF treatment. Immunomodulator use at the start of anti-TNF treatment was associated with a longer time to corticosteroid initiation, but not with longer drug survival.

Short- and medium-term outcomes following primary ileocaecal resection for Crohn's disease in two specialist centres.

BACKGROUND: Despite improvements in medical therapy, the majority of patients with Crohn's disease still require surgery. The aim of this study was to report safety, and clinical and surgical recurrence rates, including predictors of recurrence, after ileocaecal resection for Crohn's disease. METHODS: This was a cohort analysis of consecutive patients undergoing a first ileocaecal resection for Crohn's disease between 1998 and 2013 at one of two specialist centres. Anastomotic leak rate and associated risk factors were assessed. Kaplan-Meier estimates were used to describe long-term clinical and surgical recurrence. Univariable and multivariable regression analyses were performed to identify risk factors for both endpoints. RESULTS: In total, 538 patients underwent primary ileocaecal resection (40·0 per cent male; median age at surgery 31 (i.q.r. 24-42) years). Median follow-up was 6 (2-9) years. Fifteen of 507 patients (3·0 per cent) developed an anastomotic leak. An ASA fitness grade of III (odds ratio (OR) 4·34, 95 per cent c.i. 1·12 to 16·77; P = 0·033), preoperative antitumour necrosis factor therapy (OR 3·30, 1·09 to 9·99; P = 0·035) and length of resected bowel specimen (OR 1·06, 1·03 to 1·09; P < 0·001) were significant risk factors for anastomotic leak. Rates of clinical recurrence were 17·6, 45·4 and 55·0 per cent after 1, 5 and 10 years respectively. Corresponding rates of requirement for further surgery were 0·6, 6·5 and 19·1 per cent. Smoking (hazard ratio (HR) 1·67, 95 per cent c.i. 1·14 to 2·43; P = 0·008) and a positive microscopic resection margin (HR 2·16, 1·46 to 3·21; P < 0·001) were independent risk factors for clinical recurrence. Microscopic resection margin positivity was also a risk factor for further surgery (HR 2·99, 1·36 to 6·54; P = 0·006). CONCLUSION: Ileocaecal resection achieved durable medium-term remission, but smoking and resection margin positivity were risk factors for recurrence.

Randomised non-inferiority trial: 1600 mg versus 400 mg tablets of mesalazine for the treatment of mild-to-moderate ulcerative colitis.

BACKGROUND: High concentration mesalazine formulations are more convenient than conventional low concentration formulations for the treatment of ulcerative colitis (UC). AIM: To compare the efficacy and safety of 1600 mg and 400 mg tablet mesalazine formulations. METHODS: Patients with mild-to-moderate active UC (Mayo Clinic Score >5; N=817) were randomised to 3.2 g of oral mesalazine, administered as two 1600 mg tablets once, or four 400 mg tablets twice daily. We hypothesised that treatment with the 1600 mg tablet was non-inferior (within a 10% margin) to the 400 mg tablet for induction of clinical and endoscopic remission at week 8. Open-label treatment with the 1600 mg tablet continued for 26-30 weeks based on induction response. Predictors of treatment response were also explored. RESULTS: At week 8, remission occurred in 22.4% and 24.6% of patients receiving the 1600 mg and 400 mg tablets, respectively (absolute difference -2.2%, 95% CI: -8.1% to 3.8%, non-inferiority P=.005). Endoscopic and histopathologic disease activity, leucocyte concentration and age were significantly associated with clinical remission (P=.022, .042, .014 and .023, respectively). At week 38, 43.9% (296/675) of patients who continued treatment with the 1600 mg formulation were in remission, including 70.3% (142/202) of patients who received a reduced dose of mesalazine (1.6 g/d). The overall incidence of serious adverse events was low. CONCLUSIONS: Induction therapy with 3.2 mg mesalazine using two 1600 mg tablets once-daily was statistically and clinically non-inferior to a twice-daily regimen using four 400 mg tablets (NCT01903252).

Risk factors for proximal disease extension and colectomy in left-sided ulcerative colitis.

OBJECTIVE: The primary objective of this study was to assess proximal disease extension of ulcerative colitis (UC) over time, with disease behaviour pattern and risk factors for proximal disease extension and colectomy as secondary aims. METHODS: All cumulative incident cases diagnosed with UC at the Academic Medical Center between January 1990 and December 2009 were studied. The cumulative risk of colectomy was calculated by Kaplan-Meier analysis. The Cox proportional hazards regression was used to identify risk factors associated with proximal disease extension and colectomy. RESULTS: In total, 506 UC patients were included with a median age of 33 years (IQR 23-41) at diagnosis. Ninety-five (18.8%) patients underwent colectomy during follow-up. Median follow-up was 10 years (IQR 5-15). Initial disease extent was evaluable in 416 patients, of whom 142 (34.1%) had proctitis, 155 (37.3%) left-sided colitis and 119 (28.6%) pancolitis. Proximal disease extension was observed in 120 (28.8%) patients during follow-up (51 proctitis to left-sided colitis, 39 proctitis to extensive colitis and 30 left-sided to extensive colitis). Disease behaviour was evaluable in 378 patients, of whom 244 (64.6%) had less than one relapse per year. Younger age at diagnosis (HR 0.98, 95% CI 0.96-0.99) and continuous active disease (HR 2.18, 95% CI 1.27-3.73) were independent risk factors for proximal disease extension. The cumulative risk of colectomy did not change over time between patients diagnosed before and after the year 2000 (p = 0.341). Continuous active disease (HR 7.05, 95% CI 4.23-11.77), systemic steroids (HR 3.25, 95% CI 1.37-7.71) and cyclosporine treatment (HR 2.80, 95% CI 1.66-4.72) were independent risk factors for colectomy, whereas proctitis at diagnosis (HR 0.43, 95% CI 0.22-0.86) carried a lower risk. CONCLUSION: In one-third of UC patients, left-sided disease at diagnosis will extend proximally during 10 years of follow-up. Proximal disease extension was not a risk factor for colectomy, but the risk of colectomy is rather determined by continuous disease activity, and use of systemic steroids and cyclosporine.

The Future of Janus Kinase Inhibitors in Inflammatory Bowel Disease.

Inflammatory bowel diseases, such as ulcerative colitis and Crohn's disease, are disabling conditions characterised by chronic, relapsing inflammation of the gastrointestinal tract. Current treatments are not universally effective or, in the case of therapeutic antibodies, are hampered by immune responses. Janus kinase inhibitors are orally delivered small molecules that target cytokine signalling by preventing phosphorylation of Janus kinases associated with the cytokine receptor. Subsequently, phosphorylation of signal transducers and activators of transcription that relay Janus kinase signalling and transcription of cytokines in the nucleus will be diminished. Key cytokines in the pathogenesis of inflammatory bowel diseases are targeted by Janus kinase inhibitors. Several Janus kinase inhibitors are in development for the treatment of inflammatory bowel diseases. Tofacitinib, inhibiting signalling via all Janus kinase family members, was effective in phase 2 and 3 trials in moderate-severe ulcerative colitis. GSK2586184, a Janus kinase 1 selective inhibitor, induced clinical and endoscopic response in ulcerative colitis; however, the study was discontinued at an early stage due to liver toxicity observed in systemic lupus patients receiving the drug. Filgotinib, a Janus kinase 1 selective inhibitor investigated in treatment of Crohn's disease, was superior to placebo. As adverse events associated with the broad immunological effect of these agents have been reported, the future application of these drugs is potentially limited. We will discuss the treatment efficacy of Janus kinase inhibition in inflammatory bowel diseases, how current Janus kinase inhibitors available target immune responses relevant in inflammatory bowel disease, and whether more specific kinase inhibition could be effective.

Suppression of anti-drug antibodies to infliximab or adalimumab with the addition of an immunomodulator in patients with inflammatory bowel disease.

BACKGROUND: Loss of response to anti-tumour necrosis factor (TNF) therapy in patients with inflammatory bowel disease (IBD) is often caused by anti-drug antibody formation with neutralisation of drug effect. Addition of an immunomodulator has been suggested to reduce immunogenicity, leading to regained response. AIM: To investigate whether addition of an immunomodulator to anti-TNF monotherapy could lead to anti-drug antibody suppression and regained clinical response in IBD patients. METHODS: We retrospectively collected measurements of infliximab or adalimumab serum concentrations and anti-drug antibodies to identify anti-drug positive patients with loss response who were given an immunomodulator. RESULTS: Anti-drug antibodies against infliximab and adalimumab were detected in 98/376 (26%) and in 61/226 (27%) patients, respectively. Immunomodulators were given to 17/159 patients. Clinical response was recaptured in 6/10 patients receiving a thiopurine and in all (7/7) patients receiving methotrexate. In 7/8 patients on infliximab, serum concentrations increased (median 2.84 µg/mL; IQR: 1.19-4.98) and in 6/9 patients on adalimumab (median 3.10 µg/mL; IQR: 1.45-4.45). This was accompanied by a decrease in anti-drug antibodies to undetectable levels (median 11 months for both anti-TNF agents). In 23 patients, no immunomodulator was added but anti-TNF interval was shortened (17/23) or dosage was increased (6/23), which resulted in a clinical response in 10/17 and 2/6 patients, respectively. CONCLUSION: In 77% of IBD patients with loss of response due to immunogenicity, addition of immunomodulator resulted in undetectable anti-drug antibody levels, increased serum drug concentrations and regained clinical response. This strategy should be considered in this patient population before switching to other agents.