Biomarkers predicting the effect of anti-TNF treatment in paediatric and adult inflammatory bowel disease.

OBJECTIVES: Paediatric and adult inflammatory bowel disease (pIBD, aIBD) patients may lose response to anti-tumour necrosis factor (TNF) treatment within the first year. Adult-extrapolated weight-based dosing is incorrect in children, due to age-related pharmacokinetic differences. We investigated biomarkers for initial and maintenance of response to infliximab (IFX) or adalimumab (ADA), comparing pIBD and aIBD patients. METHODS: In this prospective, observational study, pIBD (n = 24) and aIBD (n = 21) patients were included when initiating anti-TNF. Escalation from standard dosing and continued anti-TNF at 12 and 18 months were assessed. Biomarkers included clinical laboratory parameters, faecal calprotectin (FCP) and IFX trough levels (TLs). Plasma proteomics was performed in pIBD. RESULTS: During our study, treatment escalation (in clinical loss of response) occurred more common in pIBD versus aIBD (p = 0.02). We established that IFX therapy escalation in pIBD patients was not due to low infliximab levels. We identified 9 pro-inflammatory proteins that were elevated in patients losing response. CONCLUSION: Anti-TNF exposure-response relationship may be different in pIBD versus aIBD. No biomarkers for maintained response were identified, but 9 inflammatory proteins were of interest as potential predictors for loss of response in pIBD.

Preoperative screening and prehabilitation strategies prior to ileocolic resection in patients with Crohn's disease are not incorporated in routine care.

PURPOSE: Recently, recommendations on perioperative care have been published to optimize postoperative outcomes in preoperative patients with inflammatory bowel disease. This study evaluated the current use of preoperative screening and prehabilitation strategies (PS) prior to elective ileocolic resection (ICR) in patients with Crohn's disease (CD). METHODS: Patients with CD who underwent an elective ICR were identified from a Dutch prospective cohort study. Primary endpoint was to evaluate to what extent IBD-relevant PS were applied in patients with CD prior to ICR according to the current recommendations. RESULTS: In total, 109 CD patients were included. Screening of nutritional status was performed in 56% of the patients and revealed malnutrition in 46% of these patients. Of the malnourished patients, 46% was referred to a dietitian. Active smoking and alcohol consumption were reported in 20% and 28%; none of these patients were referred for a cessation program. A preoperative anemia was diagnosed in 61%, and ferritin levels were assessed in 26% of these patients. Iron therapy was started in 25% of the patients with an iron deficiency anemia. Exposure to corticosteroids at time of ICR was reported in 29% and weaned off in 3%. Consultation of a dietitian, psychologist, and physiotherapist was reported in 36%, 7%, and 3%. Physical fitness was assessed in none of the patients. CONCLUSION: PS are not routinely applied and not individually tailored in the preoperative setting prior to elective ICR in patients with CD. Prior to implementation, future research on the costs and effectiveness of PS on postoperative outcomes and quality of life is necessary.

Validity of the self-administered comorbidity questionnaire in patients with inflammatory bowel disease.

Background: The International Consortium for Health Outcomes Measurement has selected the self-administered comorbidity questionnaire (SCQ) to adjust case-mix when comparing outcomes of inflammatory bowel disease (IBD) treatment between healthcare providers. However, the SCQ has not been validated for use in IBD patients. Objectives: We assessed the validity of the SCQ for measuring comorbidities in IBD patients. Design: Cohort study. Methods: We assessed the criterion validity of the SCQ for IBD patients by comparing patient-reported and clinician-reported comorbidities (as noted in the electronic health record) of the 13 diseases of the SCQ using Cohen's kappa. Construct validity was assessed using the Spearman correlation coefficient between the SCQ and the Charlson Comorbidity Index (CCI), clinician-reported SCQ, quality of life, IBD-related healthcare and productivity costs, prevalence of disability, and IBD disease activity. We assessed responsiveness by correlating changes in the SCQ with changes in healthcare costs, productivity costs, quality of life, and disease activity after 15 months. Results: We included 613 patients. At least fair agreement (κ > 0.20) was found for most comorbidities, but the agreement was slight (κ < 0.20) for stomach disease [κ = 0.19, 95% CI (-0.03; 0.41)], blood disease [κ = 0.02, 95% CI (-0.06; 0.11)], and back pain [κ = 0.18, 95% CI (0.11; 0.25)]. Correlations were found between the SCQ and the clinician-reported SCQ [ρ = 0.60, 95% CI (0.55; 0.66)], CCI [ρ = 0.39, 95% CI (0.31; 0.45)], the prevalence of disability [ρ = 0.23, 95% CI (0.15; 0.32)], and quality of life [ρ = -0.30, 95% CI (-0.37; -0.22)], but not between the SCQ and healthcare or productivity costs or disease activity (|ρ| ⩽ 0.2). A change in the SCQ after 15 months was not correlated with a change in any of the outcomes. Conclusion: The SCQ is a valid tool for measuring comorbidity in IBD patients, but face and content validity should be improved before being used to correct case-mix differences.

Superior Effectiveness of Tofacitinib Compared to Vedolizumab in Anti-TNF-experienced Ulcerative Colitis Patients: A Nationwide Dutch Registry Study.

BACKGROUND & AIMS: Clinicians face difficulty in when and in what order to position biologics and Janus kinase inhibitors in patients with anti-tumor necrosis factor-alpha (TNF) refractory ulcerative colitis (UC). We aimed to compare the effectiveness and safety of vedolizumab and tofacitinib in anti-TNF-exposed patients with UC in our prospective nationwide Initiative on Crohn and Colitis Registry. METHODS: Patients with UC who failed anti-TNF treatment and initiated vedolizumab or tofacitinib treatment were identified in the Initiative on Crohn and Colitis Registry in the Netherlands. We selected patients with both clinical as well as biochemical or endoscopic disease activity at initiation of therapy. Patients previously treated with vedolizumab or tofacitinib were excluded. Corticosteroid-free clinical remission (Simple Clinical Colitis Activity Index ≤2), biochemical remission (C-reactive protein ≤5 mg/L or fecal calprotectin ≤250 µg/g), and safety outcomes were compared after 52 weeks of treatment. Inverse propensity score-weighted comparison was used to adjust for confounding and selection bias. RESULTS: Overall, 83 vedolizumab- and 65 tofacitinib-treated patients were included. Propensity score-weighted analysis showed that tofacitinib-treated patients were more likely to achieve corticosteroid-free clinical remission and biochemical remission at weeks 12, 24, and 52 compared with vedolizumab-treated patients (odds ratio [OR], 6.33; 95% confidence interval [CI], 3.81-10.50; P < .01; OR, 3.02; 95% CI, 1.89-4.84; P < .01; and OR, 1.86; 95% CI, 1.15-2.99; P = .01; and OR, 3.27; 95% CI, 1.96-5.45; P < .01; OR, 1.87; 95% CI, 1.14-3.07; P = .01; and OR, 1.81; 95% CI, 1.06-3.09; P = .03, respectively). There was no difference in infection rate or severe adverse events. CONCLUSIONS: Tofacitinib was associated with superior effectiveness outcomes compared with vedolizumab in anti-TNF-experienced patients with UC along with comparable safety outcomes.

Effectiveness and safety of tofacitinib for ulcerative colitis: two-year results of the ICC Registry.

BACKGROUND: Tofacitinib is an oral Janus kinase (JAK) inhibitor and is registered for the treatment of ulcerative colitis (UC). The effectiveness of tofacitinib has been evaluated up to 12 months of treatment. AIM: The aim of this study was to assess the effectiveness and safety of 24 months of tofacitinib use in UC patients in the Netherlands. METHODS: Patients initiating tofacitinib treatment were included in the ICC Registry, a nationwide, observational registry. Patients were prospectively evaluated for up to 24 months. The primary outcome was corticosteroid-free clinical remission (CSFR, Simple Clinical Colitis Activity Index [SCCAI] ≤2) at week 104. Secondary outcomes included biochemical remission (C-reactive protein (CRP) ≤5 mg/L and faecal calprotectin (FC) ≤250 µg/g), safety, and discontinuation rate. RESULTS: We included 110 patients of whom 104 (94.5%) were anti-TNF experienced. After 104 weeks of tofacitinib, 31.8% (34/107) were in CSFR, 23.4% (25/107) in biochemical remission and 18.7% (20/107) in combined clinical and biochemical remission. Of the patients in CSFR at week 52, 76.5% (26/34) remained so after 104 weeks of treatment. Sixty-one patients (55.5%) discontinued tofacitinib after a median duration of 13 weeks (IQR 7-34). The main reasons for discontinuation were non-response (59%), loss of response (14.8%), and adverse events (18%). There were 33.9 possible tofacitinib-related adverse events per 100 patient-years during follow-up. Adverse events most probably related to tofacitinib were skin reactions and headaches. There were 6.4 herpes zoster infections per 100 patient-years. CONCLUSION: Tofacitinib was effective in 31.8% of patients after 24 months of treatment.

Sex-Related Differences in Patients With Inflammatory Bowel Disease: Results of 2 Prospective Cohort Studies.

Background: The understanding of gender differences in inflammatory bowel disease (IBD) patients is an important step towards tailored treatment for the individual patient. The aim of this study was to compare disease phenotype, clinical manifestations, disease activity, and healthcare utilization between men and women with Crohn's disease (CD) and ulcerative colitis (UC). Methods: Two multicenter observational cohort studies with a prospective design were used to explore the differences between men and women regarding demographic and phenotypic characteristics and healthcare utilization. Detailed data on IBD-phenotype was mainly available from the Dutch IBD Biobank, while the COIN cohort provided healthcare utilization data. Results: In the Dutch IBD Biobank study, 2118 CD patients and 1269 UC patients were analyzed. Female CD patients were more often current smokers, and male UC patients were more often previous smokers. Early onset CD (<16 years) was more frequently encountered in males than in females (20% versus 12%, P < 0.01). Male CD patients were more often diagnosed with ileal disease (28% versus 20%, P < 0.01) and underwent more often small bowel and ileocecal resection. Extraintestinal manifestations (EIMs) were more often encountered in female IBD patients. In the COIN study, 1139 CD patients and 1213 UC patients were analyzed. Male CD patients used prednisone more often and suffered more often from osteopenia. IBD-specific healthcare costs did not differ between male and female IBD patients. Conclusions: Sex differences in patients with IBD include age of onset, disease location, and EIM prevalence. No large differences in therapeutic management of IBD were observed between men and women with IBD. 10.1093/ibd/izy004_video1izy004_Video_15786481854001.

Clinical Predictors of Future Nonadherence in Inflammatory Bowel Disease.

BACKGROUND: Nonadherence to medical therapy is frequently encountered in patients with inflammatory bowel disease (IBD). We aimed to identify predictors for future (non)adherence in IBD. METHODS: We conducted a multicenter prospective cohort study with adult patients with Crohn's disease (CD) and ulcerative colitis (UC). Data were collected by means of 3-monthly questionnaires on the course of disease and healthcare utilization. Medication adherence was assessed using a visual analogue scale, ranging from 0% to 100%. Levels <80% were considered to indicate nonadherence. The Brief Illness Perception Questionnaire was used to identify illness perceptions. We used a logistic regression analysis to identify patient- and disease-related factors predictive of nonadherence 3 months after the assessment of predictors. RESULTS: In total, 1558 patients with CD and 1054 patients with UC were included and followed for 2.5 years. On average, 12.1% of patients with CD and 13.3% of patients with UC using IBD-specific medication were nonadherent. Nonadherence was most frequently observed in patients using mesalazine (CD), budesonide (UC) and rectally administrated therapy (both CD and UC). A higher perceived treatment control and understanding of the disease were associated with adherence to medical therapy. Independent predictors of future nonadherence were age at diagnosis (odds ratio [OR]: 0.99 per year), nonadherence (OR: 26.91), a current flare (OR: 1.30) and feelings of anxiety/depression (OR: 1.17), together with an area under the receiver-operating-characteristics curve of 0.74. CONCLUSIONS: Lower age at diagnosis, flares, feelings of anxiety or depression, and nonadherence are associated with future nonadherence in patients with IBD. Altering illness perceptions could be an approach to improve adherence behavior.

Prevalence of- and risk factors for work disability in Dutch patients with inflammatory bowel disease.

AIM: To determine the prevalence of work disability in inflammatory bowel disease (IBD), and to assess risk factors associated with work disability. METHODS: For this retrospective cohort study, we retrieved clinical data from the Dutch IBD Biobank on July 2014, containing electronic patient records of 3388 IBD patients treated in the eight University Medical Centers in the Netherlands. Prevalence of work disability was assessed in 2794 IBD patients and compared with the general Dutch population. Multivariate analyses were performed for work disability (sick leave, partial and full disability) and long-term full work disability (> 80% work disability for > 2 years). RESULTS: Prevalence of work disability was higher in Crohn's disease (CD) (29%) and ulcerative colitis (UC) (19%) patients compared to the general Dutch population (7%). In all IBD patients, female sex, a lower education level, and extra-intestinal manifestations, were associated with work disability. In CD patients, an age > 40 years at diagnosis, disease duration > 15 years, smoking, surgical interventions, and anti-TNFα use were associated with work disability. In UC patients, an age > 55 years, and immunomodulator use were associated with work disability. In CD patients, a lower education level (OR = 1.62, 95%CI: 1.02-2.58), and in UC patients, disease complications (OR = 3.39, 95%CI: 1.09-10.58) were associated with long-term full work disability. CONCLUSION: The prevalence of work disability in IBD patients is higher than in the general Dutch population. Early assessment of risk factors for work disability is necessary, as work disability is substantial among IBD patients.

High-dose fast infusion of parenteral iron isomaltoside is efficacious in inflammatory bowel disease patients with iron-deficiency anaemia without profound changes in phosphate or fibroblast growth factor 23.

OBJECTIVE: Iron isomaltoside (Monofer(®)) is a high-dose intravenous iron preparation with good tolerability and efficacy in inflammatory bowel disease (IBD) patients with iron deficiency anaemia (IDA). This trial evaluates the safety and efficacy, including effect on intact fibroblast growth factor 23 (iFGF23) of a high single dose and cumulative doses of iron isomaltoside in IBD patients with IDA. MATERIALS AND METHODS: The trial was a prospective, open-label, multi-centre trial conducted in IBD patients with IDA. Based upon haemoglobin (Hb) levels at baseline and weight, the patients received 1500, 2000, 2500 or 3000 mg of iron isomaltoside infused in single doses up to 2000 mg. The outcome measurements included adverse drug reactions (ADRs) and changes in haematology and biochemistry parameters. RESULTS: Twenty-one IBD patients with IDA were enrolled, receiving 1500 (seven patients), 2000 (eight patients), 2500 mg (four patients) or 3000 (two patients) mg of iron. No serious ADRs were observed. Four patients experienced nine mild to moderate ADRs (hypersensitivity, pyrexia, vomiting, constipation, abdominal pain, dyspepsia (two events) and eye allergy (two events)). In total, 15 (75%) patients had an increase in Hb of ≥2.0 g/dL during the trial, with normalisation of ferritin. No changes in iFGF23 or clinically significant hypophosphataemia were found. CONCLUSION: Rapid infusions of high-dose iron isomaltoside, administered as single doses up to 2000 mg and cumulative doses up to 3000 mg, were without safety concerns and were efficacious in increasing Hb levels in IBD patients. Iron isomaltoside did not induce profound phosphate wasting via increased iFGF23 levels.

How can we improve models of care in inflammatory bowel disease? An international survey of IBD health professionals.

BACKGROUND AND AIMS: Few studies have specifically examined models of care in IBD. This survey was designed to help gather information from health professionals working in IBD services on current care models, and their views on how to best reshape existing models for IBD care worldwide. METHODS: An online mixed-methods survey was conducted with health professionals caring for IBD patients. Recruitment was conducted using the snowballing technique, where members of professional networks of the investigators were invited to participate. Results of the survey were summarised using descriptive statistics. RESULTS: Of the 135 included respondents, 76 (56%) were female, with a median age of 44 (range: 23-69) years, 50% were GI physicians, 34% nurses, 8% psychologists, 4% dieticians, 2% surgeons, 1% psychiatrists, and 1% physiotherapists. Overall, 73 (54%) respondents considered their IBD service to apply the integrated model of care, and only 5% reported that they worked exclusively using the biomedical care (no recognition of psychosocial factors). The majority of respondents reported including mental health assessment in their standard IBD care (65%), 51% believed that an ideal IBD service should be managed in specialist led clinics, and 64% wanted the service to be publicly funded. Respondents pictured an ideal IBD service as easy-access fully multi-disciplinary, with a significant role for IBD nurses and routine psychological and nutritional assessment and care. CONCLUSIONS: Health care professionals believe that an ideal IBD service should: be fully integrated, involve significant roles of nurses, psychologists and dieticians, run in specialist clinics, be easily accessible to patients and publicly funded.

Non-colorectal intestinal tract carcinomas in inflammatory bowel disease: results of the 3rd ECCO Pathogenesis Scientific Workshop (II).

Patients with inflammatory bowel diseases (IBD) have an excess risk of certain gastrointestinal cancers. Much work has focused on colon cancer in IBD patients, but comparatively less is known about other more rare cancers. The European Crohn's and Colitis Organization established a pathogenesis workshop to review what is known about these cancers and formulate proposals for future studies to address the most important knowledge gaps. This article reviews the current state of knowledge about small bowel adenocarcinoma, ileo-anal pouch and rectal cuff cancer, and anal/perianal fistula cancers in IBD patients.

Self-efficacy in adolescents with inflammatory bowel disease: a pilot study of the "IBD-yourself", a disease-specific questionnaire.

BACKGROUND AND AIMS: Successful transfer of adolescent IBD patients to an adult gastroenterologist requires anticipation of a changing role for patients and their parents. Self-efficacy has been demonstrated to be important for transfer readiness. We therefore developed an IBD-specific questionnaire (the "IBD-yourself") to assess self-efficacy in adolescent IBD patients visiting a transition clinic. Our aim was to evaluate the reliability of this questionnaire, and to describe the self-efficacy level of adolescent IBD patients, and the perceived self-efficacy level according to their parents. METHODS: In a cross-sectional design, 50 IBD patients (aged 14-18 years) and 40 parents completed the "IBD-yourself" questionnaire. Internal reliability was assessed by standardised Cronbach's α. Median self-efficacy scores per domain were calculated. RESULTS: The domains of the questionnaire for adolescents showed good to excellent internal consistency, with Cronbach's α ranging from 0.64 to 0.93. The domains of the parental questionnaire had Cronbach's α ranging from 0.47 to 0.93. Median self-efficacy scores of adolescents varied from 70 to 100%. In comparison with patient's self-assessment, parents thought that their child was more self-efficacious in knowledge of IBD and diagnostic tests, self-management of medication use, and transfer readiness. Length of time since first visit to the transition clinic was positively correlated with several domains of the questionnaire, such as independent behaviour at the outpatient clinic, and transfer readiness. CONCLUSION: The "IBD-yourself" questionnaire is a first step toward evaluating quality and efficacy of IBD transition programmes. Paediatric gastroenterologists should be aware that parents do not always accurately assess the self-efficacy of their child.

Report of the ECCO pathogenesis workshop on anti-TNF therapy failures in inflammatory bowel diseases: definitions, frequency and pharmacological aspects.

The first ECCO pathogenesis workshop focused on anti-TNF therapy failures in inflammatory bowel diseases (IBDs). The overall objective was to better understand and explore primary non response and loss of response to anti-TNF agents in IBD. The outcome of this workshop is presented into two parts. This first section addresses definitions, frequency and pharmacological aspects of anti-TNF therapy failure, including pharmacokinetics of anti-TNF monoclonal antibodies and immune and non-immune mediated clearance of anti-TNF mAbs. The second section concerns the biological roles of TNF and TNF antagonists, including mechanisms of action of anti-TNF agents, and discuss hypothesis regarding their failures and phenomenon of paradoxical inflammation, including the potential role of TNF independent inflammatory pathways.

Genetic analysis in a Dutch study sample identifies more ulcerative colitis susceptibility loci and shows their additive role in disease risk.

OBJECTIVES: Genetic susceptibility is known to make a major contribution to the pathogenesis of ulcerative colitis (UC). Recently, three studies, including a genome-wide association study (GWAS), reported novel UC risk loci. METHODS: The top-20 single-nucleotide polymorphisms (SNPs) from the first UC-GWAS were genotyped, as part of the study's replication phase, in 561 UC cases and 728 controls from our Dutch UC study sample. We genotyped eight SNPs identified in two more studies, in these individuals, and replicated all significantly associated SNPs in an additional 894 UC cases and 1,174 controls from our Dutch UC study sample. A combined analysis for all patients (n=1,455) and controls (n=1,902) was performed. Dose-response models were constructed with the associated risk alleles. RESULTS: We found 12 SNPs tagging ten loci, including HLA-DRA, IL10, IL23R, JAK2, S100Z, ARPC2, and ECM1, to be associated with UC. We identified 10q26, flagged by the UC-GWAS but not confirmed in its replication phase, as a UC locus and found a trend toward association for GAS7. No association with disease localization or severity was found. The dose-response models show that individuals carrying 11 or more risk alleles have an odds ratio of 8.2 (confidence interval 3.0-22.8) for UC susceptibility. CONCLUSIONS: We confirmed the association of multiple loci with UC in the Dutch population and found evidence for association of 10q26 and a trend suggesting association for GAS7. Genetic models show that multiple risk loci in an individual increase the risk for developing UC.

Early combined immunosuppression or conventional management in patients with newly diagnosed Crohn's disease: an open randomised trial.

BACKGROUND: Most patients who have active Crohn's disease are treated initially with corticosteroids. Although this approach usually controls symptoms, many patients become resistant to or dependent on corticosteroids, and long exposure is associated with an increased risk of mortality. We aimed to compare the effectiveness of early use of combined immunosuppression with conventional management in patients with active Crohn's disease who had not previously received glucocorticoids, antimetabolites, or infliximab. METHODS: We did a 2-year open-label randomised trial at 18 centres in Belgium, Holland, and Germany between May, 2001, and January, 2004. We randomly assigned 133 patients to either early combined immunosuppression or conventional treatment. The 67 patients assigned to combined immunosuppression received three infusions of infliximab (5 mg/kg of bodyweight) at weeks 0, 2, and 6, with azathioprine. We gave additional treatment with infliximab and, if necessary, corticosteroids, to control disease activity. 66 patients assigned to conventional management received corticosteroids, followed, in sequence, by azathioprine and infliximab. The primary outcome measures were remission without corticosteroids and without bowel resection at weeks 26 and 52. Analysis was by modified intention to treat. This trial was registered with ClinicalTrials.gov, number NCT00554710. FINDINGS: Four patients (two in each group) did not receive treatment as per protocol. At week 26, 39 (60.0%) of 65 patients in the combined immunosuppression group were in remission without corticosteroids and without surgical resection, compared with 23 (35.9%) of 64 controls, for an absolute difference of 24.1% (95% CI 7.3-40.8, p=0.0062). Corresponding rates at week 52 were 40/65 (61.5%) and 27/64 (42.2%) (absolute difference 19.3%, 95% CI 2.4-36.3, p=0.0278). 20 of the 65 patients (30.8%) in the early combined immunosuppression group had serious adverse events, compared with 19 of 64 (25.3%) controls (p=1.0). INTERPRETATION: Combined immunosuppression was more effective than conventional management for induction of remission and reduction of corticosteroid use in patients who had been recently diagnosed with Crohn's disease. Initiation of more intensive treatment early in the course of the disease could result in better outcomes.

Chemokine production by buccal epithelium as a distinctive feature of pediatric Crohn disease.

OBJECTIVES: Inflammatory bowel diseases (IBD) represent an aberrant immune response by the mucosal immune system to luminal bacteria. Because the oral mucosa harbors the first epithelial cells that interact with microorganisms, we assessed the immunologic activity of buccal epithelium in children with IBD and adults with Crohn disease. METHODS: Buccal epithelial cells were obtained from 17 children and 14 adults with Crohn disease, 18 children with ulcerative colitis, and 40 controls. Cells were cultured with and without microbial stimulation. Chemokine levels were determined in culture supernatants by cytometric bead array and enzyme-linked immunoabsorbent assay. CXCL-8 production was studied by immunohistochemical analysis of these cells. CXCL-8 production by lipopolysaccharide stimulated monocyte-derived dendritic cells from these patients was determined. RESULTS: Compared with controls, pediatric ulcerative colitis patients, and adult Crohn disease patients, only in children with Crohn disease did buccal epithelial cells exhibit enhanced production of CXCL-8, CXCL-9, and CXCL-10. In vitro stimulation with lipopolysaccharide or zymosan resulted in a further increase of chemokine levels only in cells from pediatric Crohn disease patients. CXCL-8 production by stimulated monocyte-derived dendritic cells from children with Crohn disease was equal to that of children with ulcerative colitis. CONCLUSIONS: Buccal epithelium of children with Crohn disease is immunologically active, even in the absence of oral lesions. The enhanced chemokine production is associated with pediatric Crohn disease and appears restricted to cells derived from the epithelial barrier. Assessment of chemokine production by buccal epithelial cells may become a new, rapid, noninvasive test for screening and classification of IBD in children.

The influence of microbial metabolites on human intestinal epithelial cells and macrophages in vitro.

Microbial metabolites may influence the metabolic integrity of intestinal epithelial cells and induce mucosal immune responses. Therefore, we investigated the effects of the microbial metabolites butyrate, iso-valerate, and ammonium on Caco-2 cells and macrophages. Barrier functioning was determined by measuring transepithelial electrical resistance and basolateral recoveries of metabolites. The barrier function of Caco-2 cells remained intact after exposures. Basolateral recoveries ranged from 6.2% to 15.2%. Tumour necrosis factor-alpha and interleukin-10 were measured to determine immune reactions. The Caco-2 cells did not secrete both cytokines. Physiological concentrations of butyrate and iso-valerate stimulated the secretion of tumour necrosis factor-alpha and suppressed the secretion of interleukin-10 by macrophages that are not protected by an epithelial barrier. In contrast, ammonium concentrations as high as those produced by microbiotas of IBD patients suppressed the release of both cytokines when the barrier function is impaired.

The metabolic activity of fecal microbiota from healthy individuals and patients with inflammatory bowel disease.

The hypothesis was studied that intestinal microbial metabolites play a role in the pathogenesis of inflammatory bowel disease. For that purpose, an in vitro model of the colon was inoculated with fresh feces of six healthy individuals and eight inflammatory bowel disease patients. Samples were taken from the model over time to analyze metabolites from both saccharolytic and proteolytic fermentation. Microbiotas from inflammatory bowel disease patients produced significantly more short-chain fatty acids and ammonia than microbiotas from healthy individuals. Furthermore, the branched-chain fatty acid production was 25% higher after inoculation with microbiotas from patients than after inoculation with microbiotas from healthy individuals. Phenolic compounds were produced by all microbiotas, with large interindividual variation. The production of (potentially toxic) metabolites may play a role in the onset or chronicity of inflammatory bowel disease, because they were produced in higher amounts by microbiotas from these patients than by microbiotas from healthy individuals.