Spanish Society of Primary Care Physicians (SEMERGEN) and Spanish Working Group on Crohn's Disease and Ulcerative Colitis (GETECCU) survey on the management of patients with inflammatory bowel disease. / Encuesta Sociedad Española de Médicos de Atención Primaria (SEMERGEN) y Grupo Español de Trabajo en Enfermedad de Crohn y Colitis Ulcerosa (GETECCU) sobre el manejo de pacientes con enfermedad inflamatoria intestinal.

INTRODUCTION: Collaboration between Primary Care (PC) and Gastroenterology in inflammatory bowel disease (IBD) is crucial to provide high-quality healthcare. The aim of this study is to analyse the relationship between PC and gastroenterologists at a national level in order to identify areas for improvement in the management of patients with inflammatory bowel disease (IBD) and how to address them, with the aim of subsequently developing concrete proposals and projects between SEMERGEN and GETECCU. METHODS: Descriptive, observational, cross-sectional study, was carried out using an anonymous online questionnaire between October 2021 and March 2022. RESULTS: A total of 157 surveys from Gastroenterology and 222 from PC were collected. 43.8% and 34.3% of gastroenterologists and family practitioners, respectively, considered that there was a good relationship between the units. The level of knowledge from family practitioners regarding different aspects of IBD out of 10 was: clinical 6.67±1.48, diagnosis 6.47±1.46, treatment 5.63±1.51, follow-up 5.53±1.68 and complications 6.05±1.54. The perception of support between both units did not exceed 4.5 on a scale from 0 to 10 in either of the surveys. The most highly voted improvement proposals were better coordination between the units, implementation of IBD units, and nursing collaboration. CONCLUSION: There are deficiencies in the relationship between PC and Gastroenterology with special dedication to IBD that require the efforts of the scientific societies that represent them for greater coordination with the development of joint protocols and agile, fast, and effective communication channels.

Relevance and needs of irritable bowel syndrome (IBS): Comparison with inflammatory bowel disease (IBD). (Please, if you are not interested in IBS, read it.). / Relevancia y necesidades del síndrome del intestino irritable (SII): comparación con la enfermedad inflamatoria intestinal (EII). (Por favor, si no te interesa el SII, léelo.).

INTRODUCTION: In our opinion there is an imbalance between the relevance of irritable bowel syndrome (IBS), and the resources that are provided. OBJECTIVE: To review the different factors that determine (or should determine) the interest of gastroenterologists in IBS, comparing it with inflammatory bowel disease (IBD). For this, 7 different areas have been analyzed: (1)Medical impact; (2)Social impact; (3)Academic importance; (4)Clinical relevance; (5)Scientific relevance; (6)Public relevance, and (7)Personal aspects of the doctor. RESULTS: The prevalence is 10 times higher in IBS, which represents up to 25% of gastroenterologist visits. Both pathologies alter the quality of life, in many cases in a similar way. The social cost is very important in both cases (e.g.: absenteeism of 21% and 18%) as well as the economic cost, although much higher in medication for IBD. Academic dedication is more than double for IBD, both in university and in MIR training. Scientific relevance is greater in IBD, with a number of publications four times higher. Public relevance is not very different between the two entities, although IBD patients are more associative. Doctors prefer IBD and tend to stigmatize IBS. CONCLUSION: In our opinion, to reduce this imbalance between needs and resources, human and material, in IBS it is essential to make drastic changes both in educational aspects, communication skills, prioritization according to the demands of patients, and reward (personal and social) of physicians.

Impact of Smoking Cessation on the Clinical Course of Crohn's Disease Under Current Therapeutic Algorithms: A Multicenter Prospective Study.

OBJECTIVES: Given the importance of tobacco smoking (TS) as the only environmental factor repeatedly linked to the development of the Crohn's disease (CD), it is surprising that very few prospective studies have assessed whether TS is associated with an increased frequency of clinical relapse. Our aim was to evaluate the current impact of TS on disease relapse and the clinical benefit of quitting smoking in the present era of widespread use of anti-TNF drugs and immunosuppressants. METHODS: This was a multicenter prospective cohort study, which included 573 CD patients in clinical remission with various smoking habits. All smokers were advised to quit. Patients not exposed to tobacco before inclusion (non- and former smokers), continuing smokers, and quitters were compared regarding differences in disease outcomes during a follow-up of 4 years. RESULTS: A total of 148 continuing smokers, 190 nonsmokers, 160 former smokers, and 75 quitters were included. In comparison with nonsmokers, continuing smokers relapsed more frequently with an incidence rate ratio of 1.53 (95% confidence interval (CI): 1.10-2.17). Former smokers and quitters had similar relapse incidences compared with nonsmokers. Smoking was an independent predictor for disease relapse in the multivariate analysis (hazard ratio: 1.58 (95% CI 1.20-2.09). In the time-dependent analysis, continuing smokers had earlier relapse, regardless of anti-TNF or immunosuppressant use. CONCLUSIONS: Continuing smokers have more disease relapses, and patients who quit smoking have a similar relapse incidence compared with nonsmokers.

Long-Term Follow-Up of Patients Treated with Infliximab for Ulcerative Colitis: Predictive Factors of Response-An Observational Study.

AIM: To evaluate the early and long-term efficacy of infliximab in ulcerative colitis and to determine predictors of response and colectomy. METHODS: This is an ambidirectional cohort study in a tertiary referral center including patients who started infliximab within 2005 and 2008 and monitored until 2014. Efficacy was evaluated by partial Mayo scores at weeks 2, 4, 8, 30, and 54. Long-term treatment maintenance with infliximab and colectomy requirements were recorded. RESULTS: Fifty-three patients were included with a median follow-up of 69.5 months. Clinical remission at the time point assessments was 40.8, 47.2, 54.7, 54.7, and 49.1 %. At the time of maximal follow-up, the proportion of patients under infliximab maintenance was 24.5 %. A higher level of albumin (OR 1.4, CI 95 % 1.06-1.8; p = 0.017) was predictive of a higher remission rate at week 8. Concomitant immunomodulators beyond 6 months were predictive of infliximab's long-term maintenance (OR 15.8, CI 95 % 1.8-135.4; p = 0.012). Colectomy was required in 41.5 %. Factors associated with a higher rate of colectomy at week 54 were previous treatment with cyclosporine (OR 3.4, CI 95 % 1.2-9.7; p = 0.012), absence of response at week 8 (OR 10.3, CI 95 % 3.3-31.7; p < 0.001), and not receiving concomitant immunomodulators (OR 4.1, CI 95 % 1.8-9; p = 0.002). Colectomy rates within the first 54 weeks were closely dependent on the number of variables present: none (0 %), 1 (26.3 %), 2 (71.4 %), or 3 (100 %) of them (log rank <0.0001). CONCLUSIONS: Low albumin, previous treatment with cyclosporine, absence of a concomitant immunomodulator, and lack of response at week 8 negatively affected the efficacy of infliximab in ulcerative colitis.

Early azathioprine therapy is no more effective than placebo for newly diagnosed Crohn's disease.

BACKGROUND & AIMS: A small placebo-controlled trial reported the efficacy of mercaptopurine therapy for children newly diagnosed with Crohn's disease, yet little is known about the efficacy of early thiopurine therapy in adults. METHODS: We performed a prospective double-blind trial of adult patients with a recent (<8 weeks) diagnosis of Crohn's disease. Patients were randomly assigned to groups given azathioprine (2.5 mg · kg(-1) · day(-1), n = 68) or placebo (n = 63) at 31 hospitals from February 2006 to September 2009. Corticosteroids but no other concomitant medications were allowed for control of disease activity. The primary measure of efficacy was sustained corticosteroid-free remission. RESULTS: After 76 weeks of treatment, 30 patients treated with azathioprine (44.1%) and 23 given placebo (36.5%) were in sustained corticosteroid-free remission (difference of 7.6%; 95% confidence interval, -9.2 to 24.4%; P = .48). The rates of relapse (defined as Crohn's Disease Activity Index score >175) and corticosteroid requirements were similar between groups. A post hoc analysis of relapse, defined as a Crohn's Disease Activity Index score >220, showed lower relapse rates in the azathioprine group than in the placebo group (11.8% vs 30.2%; P = .01). Serious adverse events occurred in 14 patients in the azathioprine group (20.6%) and 7 in the placebo group (11.1%) (P = .16). A larger percentage of patients in the azathioprine group had adverse events that led to study drug discontinuation (20.6%) than in the placebo group (6.35%) (P = .02). CONCLUSIONS: In a study of adults with Crohn's disease, early azathioprine therapy was no more effective than placebo to achieve sustained corticosteroid-free remission but was more effective in preventing moderate to severe relapse in a post hoc analysis. EudraCT 2005-001186-34.

Association between variants of PRDM1 and NDP52 and Crohn's disease, based on exome sequencing and functional studies.

BACKGROUND & AIMS: Genome-wide association studies (GWAS) have identified 140 Crohn's disease (CD) susceptibility loci. For most loci, the variants that cause disease are not known and the genes affected by these variants have not been identified. We aimed to identify variants that cause CD through detailed sequencing, genetic association, expression, and functional studies. METHODS: We sequenced whole exomes of 42 unrelated subjects with CD and 5 healthy subjects (controls) and then filtered single nucleotide variants by incorporating association results from meta-analyses of CD GWAS and in silico mutation effect prediction algorithms. We then genotyped 9348 subjects with CD, 2868 subjects with ulcerative colitis, and 14,567 control subjects and associated variants analyzed in functional studies using materials from subjects and controls and in vitro model systems. RESULTS: We identified rare missense mutations in PR domain-containing 1 (PRDM1) and associated these with CD. These mutations increased proliferation of T cells and secretion of cytokines on activation and increased expression of the adhesion molecule L-selectin. A common CD risk allele, identified in GWAS, correlated with reduced expression of PRDM1 in ileal biopsy specimens and peripheral blood mononuclear cells (combined P = 1.6 × 10(-8)). We identified an association between CD and a common missense variant, Val248Ala, in nuclear domain 10 protein 52 (NDP52) (P = 4.83 × 10(-9)). We found that this variant impairs the regulatory functions of NDP52 to inhibit nuclear factor κB activation of genes that regulate inflammation and affect the stability of proteins in Toll-like receptor pathways. CONCLUSIONS: We have extended the results of GWAS and provide evidence that variants in PRDM1 and NDP52 determine susceptibility to CD. PRDM1 maps adjacent to a CD interval identified in GWAS and encodes a transcription factor expressed by T and B cells. NDP52 is an adaptor protein that functions in selective autophagy of intracellular bacteria and signaling molecules, supporting the role of autophagy in the pathogenesis of CD.

Genetic factors conferring an increased susceptibility to develop Crohn's disease also influence disease phenotype: results from the IBDchip European Project.

OBJECTIVE: Through genome-wide association scans and meta-analyses thereof, over 70 genetic loci (Crohn's disease (CD) single nucleotide polymorphisms (SNPs)) are significantly associated with CD. We aimed to investigate the influence of CD-SNPs and basic patient characteristics on CD clinical course, and develop statistical models to predict CD clinical course. DESIGN: This retrospective study included 1528 patients with CD with more than 10 years of follow-up from eight European referral hospitals. CD outcomes of interest were ileal (L1), colonic (L2) and ileocolonic disease location (L3); stenosing (B2) or penetrating behaviour (B3); perianal disease; extraintestinal manifestations; and bowel resection. A complicated disease course was defined as stenosing or penetrating behaviour, perianal disease and/or bowel resection. Association between CD-SNPs or patient characteristics and specified outcomes was studied. RESULTS: Several CD-SNPs and clinical characteristics were statistically associated with outcomes of interest. The NOD2 gene was the most important genetic factor, being an independent predictive factor for ileal location (p=2.02 × 10(-06), OR=1.90), stenosing (p=3.16 × 10(-06), OR=1.82) and penetrating (p=1.26 × 10(-02), OR=1.25) CD behaviours, and need for surgery (p=2.28 × e-05, OR=1.73), and as such was also the strongest factor associated with a complicated disease course (p=6.86 × 10(-06), OR=2.96). Immunomodulator (azathioprine/6-mercaptopurine and methotrexate) use within 3 years after diagnosis led to a reduction in bowel stenoses (p=1.48 × 10(-06), OR=0.35) and surgical rate (p=1.71 × 10(-07), OR=0.34). Association between each outcome and genetic scores, created using significant SNPs in the univariate analysis, revealed large differences in the probability of developing fistulising disease (IL23R, LOC441108, PRDM1, NOD2; p=9.64e-4, HR=1.43), need for surgery (IRGM, TNFSF15, C13ORF31, NOD2; p=7.12 × 10(-03), HR=1.35), and stenosing disease (NOD2, JAK2, ATG16L1; p=3.01 × 10(-02), HR=1.29) among patients with low and high score. CONCLUSIONS: This large multicentre cohort study has found several genetic and clinical factors influencing the clinical course of CD. NOD2 and early immunomodulator use are the clinically most meaningful predictors for its clinical course.

Assessment of anti-prothrombin antibodies in thrombosis complicating inflammatory bowel diseases.

PURPOSE: In inflammatory bowel diseases (IBD), risk of thrombosis and production of antibodies are increased. In autoimmune and inflammatory disorders, a role of anti-prothrombin (aPT) antibodies in developing thrombosis has been hypothesised. The aim of the study is to evaluate the prevalence of aPT antibodies in IBD patients, with and without thrombosis. METHODS: Thirty-three IBD patients with thrombosis, 33 IBD patients without thrombosis matched for sex, age, diagnosis and disease activity and 66 sex- and age-matched healthy controls were enrolled. Thrombosis was considered recent when blood sample was obtained within 3 months from the event. RESULTS: Prevalence of aPT antibodies in thrombotic IBD patients (3/33, 9.1 %), non-thrombotic IBD patients (4/33, 12.1 %) and in healthy subjects (3/66, 4.5 %) did not result significantly different (p = 0.377). The prevalence of aPT antibodies was more frequent in ulcerative colitis (6/32, 18.7 %) than in Crohn's disease (1/34, 2.9 %) and healthy controls (p = 0.022). Among thrombotic IBD patients, the prevalence of aPT antibodies was higher in those with recent (2/9, 22.2 %) than in those with previous thrombosis (1/24, 4.2 %) (p = 0.103). All thrombotic IBD patients with aPT antibodies were affected by ulcerative colitis with previous history of deep venous thrombosis. CONCLUSIONS: aPT antibodies do not appear to play a relevant role in thrombosis complicating IBD course. A possible association in ulcerative colitis patients with DVT could not be excluded.

Induction of dsRNA-activated protein kinase links mitochondrial unfolded protein response to the pathogenesis of intestinal inflammation.

OBJECTIVE: Inflammatory bowel diseases (IBDs) feature multiple cellular stress responses, including endoplasmic reticulum (ER) unfolded protein responses (UPRs). UPRs represent autoregulatory pathways that adjust organelle capacity to cellular demand. A similar mechanism, mitochondrial UPR (mtUPR), has been described for mitochondria. ER UPR in intestinal epithelial cells (IECs) contributes to the development of intestinal inflammation, and since mitochondrial alterations and dysfunction are implicated in the pathogenesis of IBDs, the authors characterised mtUPR in the context of intestinal inflammation. METHODS: Truncated ornithine transcarbamylase was used to selectively induce mtUPR in a murine IEC line. Dextran sodium sulphate (DSS) was administered to PKR (double-stranded-RNA-activated protein kinase) knockout mice to induce IEC stress in vivo and to test for their susceptibility to DSS-induced colitis. Expression levels of the mitochondrial chaperone chaperonin 60 (CPN60) and PKR were quantified in IECs from patients with IBDs and from murine models of colitis using immunohistochemistry and Western blot analysis. RESULTS: Selective mtUPR induction by truncated ornithine transcarbamylase transfection triggered the phosphorylation of eukaryotic translation initiation factor (eIF) 2α and cJun through the recruitment of PKR. Using pharmacological inhibitors and small inhibitory RNA, the authors identified mtUPR-induced eIF2α phosphorylation and transcription factor activation (cJun/AP1) as being dependent on the activities of the mitochondrial protease ClpP and the cytoplasmic kinase PKR. Pkr(-/-) mice failed to induce CPN60 in IECs upon DSS treatment at early time points and subsequently showed an almost complete resistance to DSS-induced colitis. Under inflammatory conditions, primary IECs from patients with IBDs and two murine models of colitis exhibited a strong induction of the mtUPR marker protein CPN60 associated with enhanced expression of PKR. CONCLUSION: PKR integrates mtUPR into the disease-relevant ER UPR via eIF2α phosphorylation and AP1 activation. Induction of mtUPR and PKR was observed in IECs from murine models and patients with IBDs. The authors' results indicate that PKR might link mitochondrial stress to intestinal inflammation.

Animal models of intestinal fibrosis: new tools for the understanding of pathogenesis and therapy of human disease.

Fibrosis is a serious condition complicating chronic inflammatory processes affecting the intestinal tract. Advances in this field that rely on human studies have been slow and seriously restricted by practical and logistic reasons. As a consequence, well-characterized animal models of intestinal fibrosis have emerged as logical and essential systems to better define and understand the pathophysiology of fibrosis. In point of fact, animal models allow the execution of mechanistic studies as well as the implementation of clinical trials with novel, pathophysiology-based therapeutic approaches. This review provides an overview of the currently available animal models of intestinal fibrosis, taking into consideration the methods of induction, key characteristics of each model, and underlying mechanisms. Currently available models will be classified into seven categories: spontaneous, gene-targeted, chemical-, immune-, bacteria-, and radiation-induced as well as postoperative fibrosis. Each model will be discussed in regard to its potential to create research opportunities to gain insights into the mechanisms of intestinal fibrosis and stricture formation and assist in the development of effective and specific antifibrotic therapies.

LIAISON® Calprotectin for the prediction of relapse in quiescent ulcerative colitis: The EuReCa study.

INTRODUCTION: Fecal calprotectin (FC) is established as a diagnostic marker to differentiate between inflammatory bowel diseases and non-inflammatory conditions. Furthermore, it may be effective in monitoring response to treatment, and to predict relapse during maintenance therapy. DESIGN: This was a prospective longitudinal study carried out in Italy, France and Spain. The primary objective was to correlate the LIAISON® Calprotectin assay measurements to quiescent ulcerative colitis (UC) or relapse as assessed by clinical data. Patients were assessed every 3 months for 12 months, and at 18 months. RESULTS: The last FC measured prior to relapse was the variable that predicted relapse in a statistically significant manner. With a 62.3 µg/g cut-off the area under the curve was 0.619, and the sensitivity was 62.9% (95% Confidence Interval [CI] 44.9%-78.5%) and specificity 63.0% (95% CI 53.1%-72.1%). Using machine learning methods, the last FC measurement was shown to have the largest impact in predicting relapse. An algorithm was developed that included other variables available following a clinician's visit, which resulted in an area under the curve of 0.754 for predicting relapse. CONCLUSION: In the present study FC measured by the LIAISON® Calprotectin assay on the visit before relapse is predictive of relapse in patients with quiescent UC. In a proof of concept, the accuracy of prediction can further be improved including other variables in an algorithm developed by machine learning. TRIAL REGISTRATION: The trial is registered at clinicaltrials.gov with reference number NCT05168917.

Mesenchymal cell proliferation and programmed cell death: key players in fibrogenesis and new targets for therapeutic intervention.

An exquisite equilibrium between cell proliferation and programmed cell death is required to maintain physiological homeostasis. In inflammatory bowel disease, and especially in Crohn's disease, enhanced proliferation along with defective apoptosis of immune cells are considered key elements of pathogenesis. Despite the relatively limited attention that has been given to research efforts devoted to intestinal fibrosis to date, there is evidence suggesting that enhanced proliferation along with defective programmed cell death of mesenchymal cells can significantly contribute to the development of excessive fibrogenesis in many different tissues. Moreover, some therapies have demonstrated potential antifibrogenic efficacy through the regulation of mesenchymal cell proliferation and programmed cell death. Further understanding of the pathways involved in the regulation of mesenchymal cell proliferation and apoptosis is, however, required.

Clinical patterns and outcomes of ischaemic colitis: results of the Working Group for the Study of Ischaemic Colitis in Spain (CIE study).

BACKGROUND: There is a lack of prospective studies evaluating the natural history of colonic ischaemia (CI). We performed such a study to evaluate the clinical presentation, outcome, and mortality as well as clinical variables associated with poor prognosis. METHODS: An open, prospective, and multicentre study was conducted in 24 Spanish hospitals serving a population of 3.5 million people. The study included only patients who met criteria for definitive or probable CI. A website (www.colitisisquemica.org) provided logistical support. RESULTS: A total of 364 patients met criteria for inclusion. CI was suspected clinically in only 24.2% of cases. The distribution of clinical patterns was as follows: reversible colopathy (26.1%), transient colitis (43.7%), gangrenous colitis (9.9%), fulminant pancolitis (2.5%), and chronic segmental colitis (17.9%). A total of 47 patients (12.9%) had an unfavorable outcome as defined by mortality and/or the need for surgery. Multivariate analysis identified the following signs as independent risk factors for an unfavorable outcome: abdominal pain without rectal bleeding [odds ratio (OR) 3.9; 95% confidence interval (CI) = 1.6-9.3], non-bloody diarrhoea (OR 10; 95% CI = 3.7-27.4), and peritoneal signs (OR 7.3; 95% CI = 2.7-19.6). Unfavorable outcomes also were more frequent in isolated right colon ischaemia (IRCI) compared with non-IRCI (40.9 vs. 10.3%, respectively; p < 0.0001). The overall mortality rate was 7.7%. CONCLUSIONS: The clinical presentation of CI is very heterogeneous, perhaps explaining why clinical suspicion of this disease is so low. The presence of IRCI, and occurrence of peritoneal signs or onset of CI as severe abdominal pain without bleeding, should alert the physician to a potentially unfavorable course.

International Perspectives on Management of Inflammatory Bowel Disease: Opinion Differences and Similarities Between Patients and Physicians From the IBD GAPPS Survey.

BACKGROUND: Inflammatory bowel diseases (IBD), including Crohn disease (CD) and ulcerative colitis (UC), are complex disorders with multiple comorbidities. We conducted international patient and physician surveys to evaluate current experiences and perceptions of patients with CD or UC and physicians who treat IBD. METHODS: The IBD Global Assessment of Patient and Physician Unmet Need Surveys comprised a patient survey and a physician survey, fielded in North America and Europe between August 16, 2019, and November 10, 2019. Adults with CD or UC (targeted 1:1 ratio) were recruited from physicians, patient advocacy groups, and recruitment panels; physicians were recruited by recruitment agencies and panels. RESULTS: In total, 2398 patients with IBD (1368 CD, 1030 UC) and 654 physicians completed surveys. Anxiety and depression were the most common comorbidities among patients with IBD. Patients and physicians were generally aligned on treatment goals and patient-physician communication. Patients with IBD reported high quality-of-life impact by rectal urgency and need to use the toilet, which were rated as lower-impact by physicians. Patients defined remission based on symptoms; physicians defined remission based primarily on clinical tests. Patients expected current treatments to control their disease for a longer duration than did physicians. Patients expressed more concern about corticosteroid use compared with physicians; many physicians reported prescribing corticosteroids for more than 4 months per year in some patients. CONCLUSIONS: Patients could benefit from education about disease remission and expectations for current therapies. High corticosteroid use is concerning to patients, and physicians should minimize the use of corticosteroids for extended periods of time.

Crucial role of the protein C pathway in governing microvascular inflammation in inflammatory bowel disease.

Endothelial protein C receptor (EPCR) and thrombomodulin (TM) are expressed at high levels in the resting microvasculature and convert protein C (PC) into its activated form, which is a potent anticoagulant and antiinflammatory molecule. Here we provide evidence that in Crohn disease (CD) and ulcerative colitis (UC), the 2 major forms of inflammatory bowel disease (IBD), there was loss of expression of endothelial EPCR and TM, which in turns caused impairment of PC activation by the inflamed mucosal microvasculature. In isolated human intestinal endothelial cells, administration of recombinant activated PC had a potent antiinflammatory effect, as demonstrated by downregulated cytokine-dependent cell adhesion molecule expression and chemokine production as well as inhibited leukocyte adhesion. In vivo, administration of activated PC was therapeutically effective in ameliorating experimental colitis as evidenced by reduced weight loss, disease activity index, and histological colitis scores as well as inhibited leukocyte adhesion to the inflamed intestinal vessels. The results suggest that the PC pathway represents a new system crucially involved in governing intestinal homeostasis mediated by the mucosal microvasculature. Restoring the PC pathway may represent a new therapeutic approach to suppress intestinal inflammation in IBD.

VEGF-A links angiogenesis and inflammation in inflammatory bowel disease pathogenesis.

BACKGROUND & AIMS: Vascular endothelial growth factor A (VEGF-A) mediates angiogenesis and might also have a role in inflammation and immunity. We examined whether VEGF-A signaling has a role in inflammatory bowel disease (IBD). METHODS: Expression levels of VEGF-A, and its receptors VEGFR-1 and VEGFR-2, were examined in samples from patients with IBD and compared with those of controls. The capacity of VEGF-A to induce angiogenesis was tested in human intestinal microvascular endothelial cells using cell-migration and matrigel tubule-formation assays. Levels of vascular cellular adhesion molecule-1 and intercellular adhesion molecule were measured by flow cytometry to determine induction of inflammation; neutrophil adhesion was also assayed. Expression patterns were determined in tissues from mice with dextran sulfate sodium (DSS)-induced colitis; the effects of VEGF-A overexpression and blockade were assessed in these mice by adenoviral transfer of VEGF-A and soluble VEGFR-1. Intestinal angiogenesis was measured by quantitative CD31 staining and leukocyte adhesion in vivo by intravital microscopy. RESULTS: Levels of VEGF-A and VEGFR-2 increased in samples from patients with IBD and colitic mice. VEGF-A induced angiogenesis of human intestinal microvascular endothelial cells in vitro as well as an inflammatory phenotype and adherence of neutrophils to intestinal endothelium. Overexpression of VEGF-A in mice with DSS-induced colitis worsened their condition, whereas overexpression of soluble VEGFR-1 had the opposite effect. Furthermore, overexpression of VEGF-A increased mucosal angiogenesis and stimulated leukocyte adhesion in vivo. CONCLUSIONS: VEGF-A appears to be a novel mediator of IBD by promoting intestinal angiogenesis and inflammation. Agents that block VEGF-A signaling might reduce intestinal inflammation in patients with IBD.

The role of MAPK in governing lymphocyte adhesion to and migration across the microvasculature in inflammatory bowel disease.

Lymphocyte recruitment is a key pathogenic event in inflammatory bowel disease (IBD). Adhesion of T cells to human intestinal microvascular endothelial cells (HIMEC) is mediated by ICAM-1, VCAM-1 and fractalkine (FKN), but the signaling molecules that orchestrate this process have yet to be identified. Because MAPK play an important role in the response of many cell types to pro-inflammatory stimuli, we assessed the functional role of p38 MAPK, p42/44 MAPK and JNK in the regulation of lymphocyte adhesion to and chemotaxis across the microvasculature in IBD. We found that the MAPK were phosphorylated in the bowel microvasculature and human intestinal fibroblasts of patients with IBD but not of healthy individuals. Stimulation of HIMEC with TNF-alpha triggered phosphorylation of the MAPK, and up-regulation of VCAM-1, FKN and ICAM-1. Blockade of p38 decreased the expression of all MAPK by 50% (p<0.01), whereas inhibition of p42/44 decreased the expression of ICAM-1 and FKN by 50% (p<0.01). Treatment of human intestinal fibroblasts with TNF-alpha elicited production of IL-8 and MCP-1, which was reduced (p<0.05) by blockade of p38 and p42/44. Finally, blockade of p38 and p42/44 reduced lymphocyte adhesion to (p<0.05) and transmigration across (p<0.05) HIMEC monolayers. These findings suggest a critical role for MAPK in governing lymphocyte influx into the gut in IBD patients, and their blockade may offer a molecular target for blockade of leukocyte recruitment to the intestine.

Pathogenic mechanisms of postinfectious functional gastrointestinal disorders: results 3 years after gastroenteritis.

OBJECTIVE: Functional gastrointestinal disorders (FGID) may appear after acute gastroenteritis. The aim of this study was to evaluate the possible mechanisms (inflammation, visceral hypersensitivity, psychological and immunogenetic factors) related to the development of postinfectious (PI) FGID 3 years after a Salmonella outbreak. MATERIAL AND METHODS: Biopsies of the antrum, and right- and left colon from 16 PI-FGID patients, 8 PI control patients, and 18 healthy controls (H-controls) were processed for immunohistochemistry, cytokines, and mast-cell electron microscopy. DNA was typed for cytokine gene polymorphisms. Visceral sensitivity (satiety test and rectal barostat) and psychological factors (SCL-90 and vital events) were assessed. RESULTS: The number of mast cells and T lymphocytes was similar among the groups in all locations. Mast cells within 5 microm of nerve fibers of both PI groups were increased compared to H-controls: (stomach: 5.6+/-1.2 versus 6.6+/-1.5 versus 2.5+/-1.1; right colon: 9.7+/-1.3 versus 8.0+/-1.3 versus 4.1+/-1.7; left colon: 8.9+/-0.9 versus 8.5+/-1.8 versus 2.2+/-2.0 per field) (p<0.05). No differences in the production of IL-1beta, IL-1ra, IL-6, and IL-10 or in their genotypes were found. PI-FGID patients showed a lower pain threshold to rectal distention (29+/-2 versus 37+/- 2 mmHg; p<0.05). Scores for anxiety (0.63+/-0.11 versus 0.28+/-0.14) and somatization (1.01+/-0.15 versus 0.45+/-0.15) were higher in PI-FGID patients than in PI controls (p<0.05). The number of stressful life events was not significantly different between both PI groups. CONCLUSIONS: Three years after salmonellosis, PI-FGID patients showed no evidence of inflammation in the gastric or colonic mucosa, but visceral sensitivity and anxiety/somatization levels were increased. The close anatomical mast cell-nerve fibers relation does not seem to be related to the FGID but to the infection itself.

Probiotics for inflammatory bowel disease: a critical appraisal.

The notion that the intestinal microbiota plays a key role for the development of intestinal inflammation, initially based on a series of clinical observations both in human inflammatory bowel disease and experimental colitis, has been reinforced by a growing body of evidence demonstrating that the abnormal recognition of bacterial and other microbiota antigens by the innate immune system is one of the earliest events in the pathogenesis of inflammatory bowel disease. In keeping with our present knowledge of inflammatory bowel disease pathophysiology, the search for therapeutic approaches aimed at modifying the composition of the intestinal microbiota to obtain new, more targeted treatments for inflammatory bowel disease that are basically free of side effects has been a subject of intense research activity. Probiotics are defined as live organisms capable of conferring health benefits beyond their nutritional properties. Numerous micro-organisms have been evaluated to induce or maintain remission, or both, in ulcerative colitis, Crohn's disease and pouchitis. Overall, probiotics have successfully demonstrated some efficacy in some inflammatory bowel disease scenarios. However, a critical review of the available scientific literature shows that: (1) in spite of great expectations, reflected by a high number of review and editorial articles in top journals, the number of published, well-designed clinical trials using probiotics in inflammatory bowel disease is small, often with few patients; (2) the range of microbial agents makes it particularly difficult to draw global conclusions; (3) the quality of the evidence on the efficacy of probiotics in pouchitis is clearly better than that in ulcerative colitis, while there is virtually no evidence of probiotic efficacy in Crohn's disease. The appropriate selection of probiotic agents combined with convincing clinical trials will determine whether probiotics can jump from promise to reality in inflammatory bowel disease clinical practice.