Mycophenolate mofetil-associated collagenous ileitis in a kidney transplant recipient: A case report.

We report a case of mycophenolate mofetil-induced collagenous ileitis in a kidney transplant patient. A 38-year-old Chinese man who had received a kidney transplant 3 years earlier was admitted to our department for severe diarrhea and rapid weight loss. Infection studies were negative, and tumors were ruled out, so drug-induced factors were suspected. He had been taking mycophenolate mofetil for immunosuppression, which was then suspended, and he had a rapid resolution of diarrhea. Pathological findings of gastrointestinal endoscopy biopsy showed the presence of thickened collagen bands in the subepithelium of the terminal ileum. This is the first report of collagenous ileitis caused by mycophenolate mofetil in a patient with a kidney transplantation, adding another reversible cause to this rare condition. It is important for clinicians to recognize and treat it promptly.

Harnessing murine models of Crohn's disease ileitis to advance concepts of pathophysiology and treatment.

Crohn's disease (CD) and ulcerative colitis (UC) are both characterized by chronic inflammation and severe dysfunction of the gastrointestinal tract. These two forms of inflammatory bowel disease (IBD) represent distinct clinical disorders with diverse driving mechanisms; however, this divergence is not reflected in currently approved therapeutics that commonly target general proinflammatory pathways. A compelling need therefore remains to understand factors that differentiate the topology and the distinct clinical manifestations of CD versus UC, in order to develop more effective and specialized therapies. Animal models provide valuable platforms for studying IBD heterogeneity and deciphering disease-specific mechanisms. Both the established and the newly developed ileitis mouse models are characterized by various disease initiating mechanisms and diverse phenotypic outcomes that reflect the complexity of human CD-ileitis. Microbial dysbiosis, destruction of epithelial barrier integrity, immune cell deregulation, as well as the recently described genome instability and stromal cell activation have all been proposed as the triggering factors for the development of ileitis-associated pathology. In this review, we aim to critically evaluate the mechanistic underpinnings of murine models of CD-ileitis, discuss their phenotypic similarities to human disease, and envisage their further exploitation for the development of novel targeted and personalized therapeutics.

Location is important: differentiation between ileal and colonic Crohn's disease.

Crohn's disease can affect any part of the gastrointestinal tract; however, current European and national guidelines worldwide do not differentiate between small-intestinal and colonic Crohn's disease for medical treatment. Data from the past decade provide evidence that ileal Crohn's disease is distinct from colonic Crohn's disease in several intestinal layers. Remarkably, colonic Crohn's disease shows an overlap with regard to disease behaviour with ulcerative colitis, underlining the fact that there is more to inflammatory bowel disease than just Crohn's disease and ulcerative colitis, and that subtypes, possibly defined by location and shared pathophysiology, are also important. This Review provides a structured overview of the differentiation between ileal and colonic Crohn's disease using data in the context of epidemiology, genetics, macroscopic differences such as creeping fat and histological findings, as well as differences in regard to the intestinal barrier including gut microbiota, mucus layer, epithelial cells and infiltrating immune cell populations. We also discuss the translation of these basic findings to the clinic, emphasizing the important role of treatment decisions. Thus, this Review provides a conceptual outlook on a new mechanism-driven classification of Crohn's disease.

Electroacupuncture intervention of visceral hypersensitivity is involved in PAR-2-activation and CGRP-release in the spinal cord.

Electroacupuncture (EA) relieves visceral hypersensitivity (VH) with underlying inflammatory bowel diseases. However, the mechanism by which EA treats ileitis-induced VH is not clearly known. To assess the effects of EA on ileitis-induced VH and confirm whether EA attenuates VH through spinal PAR-2 activation and CGRP release, goats received an injection of 2,4,6-trinitro-benzenesulfonic-acid (TNBS) solution into the ileal wall. TNBS-injected goats were allocated into VH, Sham acupuncture (Sham-A) and EA groups, while goats treated with saline instead of TNBS solution were used as the control. Goats in EA group received EA at bilateral Hou-San-Li acupoints for 0.5 h at 7 days and thereafter repeated every 3 days for 6 times. Goats in the Sham-A group were inserted with needles for 0.5 h at the aforementioned acupoints without any hand manipulation and electric stimulation. Visceromotor responses to colorectal distension, an indicator of VH, were recorded by electromyography. The terminal ileum and thoracic spinal cord (T11) were sampled for evaluating ileitis at days 7 and 22, and distribution and expression-levels of PAR-2, CGRP and c-Fos on day 22. TNBS-treated-goats exhibited apparent transmural-ileitis on day 7, microscopically low-grade ileitis on day 22 and VH at days 7-22. Goats of Sham-A, VH or EA group showed higher (P < 0.01) VH at days 7-22 than the Control-goats. EA-treated goats exhibited lower (P < 0.01) VH as compared with Sham-A or VH group. Immunoreactive-cells and expression-levels of spinal PAR-2, CGRP and c-Fos in the EA group were greater (P < 0.01) than those in the Control group, but less (P < 0.01) than those in Sham-A and VH groups on day 22. Downregulation of spinal PAR-2 and CGRP levels by EA attenuates the ileitis and resultant VH.

Human Gut Microbiome Transplantation in Ileitis Prone Mice: A Tool for the Functional Characterization of the Microbiota in Inflammatory Bowel Disease Patients.

BACKGROUND: Inflammatory bowel disease (IBD) is a lifelong digestive disease characterized by periods of severe inflammation and remission. To our knowledge, this is the first study showing a variable effect on ileitis severity from human gut microbiota isolated from IBD donors in remission and that of healthy controls in a mouse model of IBD. METHODS: We conducted a series of single-donor intensive and nonintensive fecal microbiota transplantation (FMT) experiments using feces from IBD patients in remission and healthy non-IBD controls (N = 9 donors) in a mouse model of Crohn's disease (CD)-like ileitis that develops ileitis in germ-free (GF) conditions (SAMP1/YitFC; N = 96 mice). RESULTS: Engraftment studies demonstrated that the microbiome of IBD in remission could have variable effects on the ileum of CD-prone mice (pro-inflammatory, nonmodulatory, or anti-inflammatory), depending on the human donor. Fecal microbiota transplantation achieved a 95% ± 0.03 genus-level engraftment of human gut taxa in mice, as confirmed at the operational taxonomic unit level. In most donors, microbiome colonization abundance patterns remained consistent over 60 days. Microbiome-based metabolic predictions of GF mice with Crohn's or ileitic-mouse donor microbiota indicate that chronic amino/fatty acid (valine, leucine, isoleucine, histidine; linoleic; P < 1e-15) alterations (and not bacterial virulence markers; P > 0.37) precede severe ileitis in mice, supporting their potential use as predictors/biomarkers in human CD. CONCLUSION: The gut microbiome of IBD remission patients is not necessarily innocuous. Characterizing the inflammatory potential of each microbiota in IBD patients using mice may help identify the patients' best anti-inflammatory fecal sample for future use as an anti-inflammatory microbial autograft during disease flare-ups.

Cost-effectiveness of laparoscopic ileocaecal resection versus infliximab treatment of terminal ileitis in Crohn's disease: the LIR!C Trial.

OBJECTIVE: Evaluate the cost-effectiveness of laparoscopic ileocaecal resection compared with infliximab in patients with ileocaecal Crohn's disease failing conventional therapy. DESIGN: A multicentre randomised controlled trial was performed in 29 centres in The Netherlands and the UK. Adult patients with Crohn's disease of the terminal ileum who failed >3 months of conventional immunomodulators or steroids without signs of critical strictures were randomised to laparoscopic ileocaecal resection or infliximab. Outcome measures included quality-adjusted life-years (QALYs) based on the EuroQol (EQ) 5D-3L Questionnaire and the Inflammatory Bowel Disease Questionnaire (IBDQ). Costs were measured from a societal perspective. Analyses were performed according to the intention-to-treat principle. Missing cost and effect data were imputed using multiple imputation. Cost-effectiveness planes and cost-effectiveness acceptability curves were estimated to show uncertainty. RESULTS: In total, 143 patients were randomised. Mean Crohn's disease total direct healthcare costs per patient at 1 year were lower in the resection group compared with the infliximab group (mean difference €-8931; 95% CI €-12 087 to €-5097). Total societal costs in the resection group were lower than in the infliximab group, however not statistically significant (mean difference €-5729, 95% CI €-10 606 to €172). The probability of resection being cost-effective compared with infliximab was 0.96 at a willingness to pay (WTP) of €0 per QALY gained and per point improvement in IBDQ Score. This probability increased to 0.98 at a WTP of €20 000/QALY gained and 0.99 at a WTP of €500/point of improvement in IBDQ Score. CONCLUSION: Laparoscopic ileocaecal resection is a cost-effective treatment option compared with infliximab. CLINICAL TRIAL REGISTRATION NUMBER: Dutch Trial Registry NTR1150; EudraCT number 2007-005042-20 (closed on 14 October 2015).

Effects of Bifidobacterium infantis on cytokine-induced neutrophil chemoattractant and insulin-like growth factor-1 in the ileum of rats with endotoxin injury.

BACKGROUND: The digestive tract is the maximal immunizing tissue in the body, and mucosal integrity and functional status of the gut is very important to maintain a healthy organism. Severe infection is one of the most common causes of gastrointestinal dysfunction, and the pathogenesis is closely related to endotoxemia and intestinal barrier injury. Bifidobacterium is one of the main probiotics in the human body that is involved in digestion, absorption, metabolism, nutrition, and immunity. Bifidobacterium plays an important role in maintaining the intestinal mucosal barrier integrity. This study investigated the protective mechanism of Bifidobacterium during ileal injury in rats. AIM: To investigate the effects of Bifidobacterium on cytokine-induced neutrophil chemoattractant (CINC) and insulin-like growth factor 1 (IGF-1) in the ileum of rats with endotoxin injury. METHODS: Preweaning rats were randomly divided into three groups: Control (group C), model (group E) and treatment (group T). Group E was intraperitoneally injected with lipopolysaccharide (LPS) to create an animal model of intestinal injury. Group T was intragastrically administered Bifidobacterium suspension 7 d before LPS. Group C was intraperitoneally injected with normal saline. The rats were killed at 2, 6 or 12 h after LPS or physiological saline injection to collect ileal tissue samples. The expression of ileal CINC mRNA was evaluated by reverse transcription-polymerase chain reaction (RT-PCR), and expression of ileal IGF-1 protein and mRNA was detected by immunohistochemistry and RT-PCR, respectively. RESULTS: The ileum of rats in Group C did not express CINC mRNA, ileums from Group E expressed high levels, which was then significantly decreased in Group T (F = 23.947, P < 0.05). There was no significant difference in CINC mRNA expression at different times (F = 0.665, P > 0.05). There was a high level of IGF-1 brown granules in ileal crypts and epithelial cells in Group C, sparse staining in Group E, and dark, dense brown staining in Group T. There was a significant difference between Groups C and E and Groups E and T (P < 0.05). There was no significant difference in IGF-1 protein expression at different times (F = 1.269, P > 0.05). IGF-1 mRNA expression was significantly different among the three groups (P < 0.05), though not at different times (F = 0.086, P > 0.05). CONCLUSION: Expression of CINC mRNA increased in the ileum of preweaning rats with endotoxin injury, and exogenous administration of Bifidobacterium reduced CINC mRNA expression. IGF-1 protein and mRNA expression decreased in the ileum of preweaning rats with endotoxin injury, and exogenous administration of Bifidobacterium prevented the decrease in IGF-1 expression. Bifidobacterium may increase IGF-1 expression and enhance intestinal immune barrier function in rats with endotoxin injury.

Pituitary Adenylate Cyclase-Activating Polypeptide-A Neuropeptide as Novel Treatment Option for Subacute Ileitis in Mice Harboring a Human Gut Microbiota.

The neuropeptide Pituitary adenylate cyclase-activating polypeptide (PACAP) is well-known for its important functions in immunity and inflammation. Data regarding anti-inflammatory properties of PACAP in the intestinal tract are limited, however. In our present preclinical intervention study we addressed whether PACAP treatment could alleviate experimental subacute ileitis mimicking human gut microbiota conditions. Therefore, secondary abioitic mice were subjected to human fecal microbiota transplantation (FMT) and perorally infected with low-dose Toxoplasma gondii to induce subacute ileitis on day 0. From day 3 until day 8 post-infection, mice were either treated with synthetic PACAP38 or placebo. At day 9 post-infection, placebo, but not PACAP treated mice exhibited overt macroscopic sequelae of intestinal immunopathology. PACAP treatment further resulted in less distinct apoptotic responses in ileal and colonic epithelia that were accompanied by lower T cell numbers in the mucosa and lamina propria and less secretion of pro-inflammatory cytokines in intestinal ex vivo biopsies. Notably, ileitis-associated gut microbiota shifts were less distinct in PACAP as compared to placebo treated mice. Inflammation-ameliorating effects of PACAP were not restricted to the intestines, but could also be observed in extra-intestinal including systemic compartments as indicated by lower apoptotic cell counts and less pro-inflammatory cytokine secretion in liver and lungs taken from PACAP treated as compared to placebo control mice, which also held true for markedly lower serum TNF and IL-6 concentrations in the former as compared to the latter. Our preclinical intervention study provides strong evidence that synthetic PACAP alleviates subacute ileitis and extra-intestinal including systemic sequelae of T cell-driven immunopathology. These findings further support PACAP as a novel treatment option for intestinal inflammation including inflammatory bowel diseases (IBD).

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

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

Acute Terminal Ileitis in Children: A Retrospective Study in a Pediatric Emergency Department.

OBJECTIVES: This study aims to describe the clinical presentation and outcome of patients diagnosed with acute ileitis in our pediatric emergency department. METHODS: We performed a retrospective study of all patients diagnosed with terminal ileitis by abdominal ultrasonography findings in our pediatric emergency department, over the years 2013 and 2014. Patients with previous diagnosis of inflammatory bowel disease (IBD) were excluded. Data collected were clinical, radiological, and laboratory data at diagnosis; outcome including hospitalization care; and outpatient follow-up in pediatric gastroenterology and/or primary care. RESULTS: A total of 20 cases were retrieved and studied. All of them presented with abdominal pain, 65% located in the right lower quadrant. Leukocyte count, C-reactive protein, and fibrinogen levels (means, 12,889; 4/µL; 50.1 mg/L; and 575 mg/dL, respectively) were above normal range. Hemoglobin and platelet count were normal. A microbial cause of ileitis was found in 3 cases (Yersinia enterocolitica, Campylobacter jejuni, and Adenovirus). Nine patients were referred to a pediatric gastroenterology unit. No cases of IBD were found. CONCLUSIONS: Acute ileitis is a rare and benign cause of abdominal pain in the pediatric emergency department. The main intervention on initial assessment is to rule out potentially severe causes of abdominal pain that could benefit of an emergency surgical procedure. In contrast with adults and adolescents, acute ileitis in children does not have a clear association with development of IBD.

Dietary Fiber Pectin Directly Blocks Toll-Like Receptor 2-1 and Prevents Doxorubicin-Induced Ileitis.

Dietary carbohydrate fibers are known to prevent immunological diseases common in Western countries such as allergy and asthma but the underlying mechanisms are largely unknown. Until now beneficial effects of dietary fibers are mainly attributed to fermentation products of the fibers such as anti-inflammatory short-chain fatty acids (SCFAs). Here, we found and present a new mechanism by which dietary fibers can be anti-inflammatory: a commonly consumed fiber, pectin, blocks innate immune receptors. We show that pectin binds and inhibits, toll-like receptor 2 (TLR2) and specifically inhibits the proinflammatory TLR2-TLR1 pathway while the tolerogenic TLR2-TLR6 pathway remains unaltered. This effect is most pronounced with pectins having a low degree of methyl esterification (DM). Low-DM pectin interacts with TLR2 through electrostatic forces between non-esterified galacturonic acids on the pectin and positive charges on the TLR2 ectodomain, as confirmed by testing pectin binding on mutated TLR2. The anti-inflammatory effect of low-DM pectins was first studied in human dendritic cells and mouse macrophages in vitro and was subsequently tested in vivo in TLR2-dependent ileitis in a mouse model. In these mice, ileitis was prevented by pectin administration. Protective effects were shown to be TLR2-TLR1 dependent and independent of the SCFAs produced by the gut microbiota. These data suggest that low-DM pectins as a source of dietary fiber can reduce inflammation through direct interaction with TLR2-TLR1 receptors.

Prepouch Ileitis After Ileal Pouch-anal Anastomosis: Patterns of Presentation and Risk Factors for Failure of Treatment.

BACKGROUND AND AIMS: There is a lack in the literature about prepouch ileitis [PI], in particular regarding risk factors associated with failure of the medical treatment. Aim of the study is to analyse the characteristics of PI patients and to compare those who required surgery with those who were successfully treated with conservative therapy. METHODS: All cases presenting a diagnosis of PI were included and analysed. Patients eventually requiring surgery were compared with those who were managed conservatively, for symptoms of presentation, endoscopic characteristics, and rate of response to medical treatment. A sub-analysis of outcomes based on the final histology was performed. RESULTS: The overall incidence of PI among 1286 patients was 4.4% [57], after a median of 6.8 years from pouch surgery. Symptoms included increased frequency [26.4%], outlet obstruction [21%], and bleeding [15.8%]. Afferent limb stenosis affected 49.1% of patients. The comparison showed that patients requiring surgery had a higher rate of Crohn's disease and indeterminate colitis [42.1 vs 0% and 15.8 vs 2.6%, p < 0.0001], outlet obstruction as main symptom [47.4 vs 7.9%, p = 0.0023], and afferent limb stenosis [73.7 vs 36.8%, p = 0.008] at endoscopy. Rate of failure of medical treatment at 5 years was 8.2% in patients with ulcerative colitis and 75% in the presence of both indeterminate colitis and Crohn's disease [p < 0.0001]. CONCLUSIONS: Crohn's disease, indeterminate colitis, and stenosis with outlet obstruction are risk factors for failure of treatment after diagnosis of PI. Early aggressive therapy and surgery should be considered in these cases.

Fatal Campylobacter jejuni ileocolitis.

Campylobacter infection usually starts in the jejunum and ileum and progresses distally. The case fatality rate is low and most occur in elderly or patients with comorbidity as in this case. Antibiotics should be used in severe cases or patients at risk. The choices are macrolides and fluoroquinolones. However, in some countries quinolone resistance is increasing, as in Spain. We shouldn´t forget this fact for the proper treatment approach and specifically in refractory cases.

Frequency, natural course and clinical significance of symptomatic terminal ileitis.

OBJECTIVE: Treatment guidelines for managing symptomatic terminal ileitis (TI) are lacking. We followed up a cohort of symptomatic TI patients to conduct an algorithm for their management. METHODS: Consecutive patients with symptomatic TI from July 2007 to October 2013 were included. Symptomatic TI was defined as isolated terminal ileum ulceration (superficial or deep) and/or nodularity with abdominal symptoms. Patients were diagnosed either with intestinal tuberculosis (ITB) or Crohn's disease (CD) using standard criteria or received only symptomatic treatment according to their clinical manifestations, endoscopic, imaging and histological (specific to ITB/CD vs non-specific) features. Based upon above findings, an algorithm was conducted to differentiate non-specific TI from those with specific etiology (ITB/CD). RESULTS: In all, 63/898 (7.0%) patients with ulcero-constrictive intestinal disease had TI, of which 45 (26 males and 19 females) were included. Fever, diarrhea, weight loss, deep ulcers, and ileal thickening were more frequently observed in patients with ITB or CD having specific treatments compared with those receiving symptomatic treatments. All patients with deep ulcers and those with superficial ulcer and specific histology had ITB/CD. In patients with superficial ulcers and/or nodularity and non-specific inflammation (n = 31), the absence of fever, diarrhea, GI bleeding or weight loss had a negative predictive value of 92% in excluding ITB/CD. CONCLUSIONS: In symptomatic TI patients with superficial ulcers and a non-specific histology, the absence of fever, diarrhea, GI bleeding or weight loss rules out the possibility of significant diagnoses like ITB/CD.

Fecal Microbial Transplant After Ileocolic Resection Reduces Ileitis but Restores Colitis in IL-10-/- Mice.

BACKGROUND: Ileocolic resection (ICR) is frequently performed for Crohn's disease; however, disease commonly recurs early in the neoterminal ileum. The aim of this study was to use the IL-10(-/-) mouse to determine the effects of ICR on gut microbiome and immune function and if postoperative fecal microbial transplant (FMT) would improve disease. METHODS: ICR was performed in 129S1/SvlmJ IL10(-/-) mice followed by FMT using stool from wild-type mice. Sham-transplant mice received their own stool. Stool samples were collected on day 0, day 13 (after ICR), and day 27 (after FMT) for whole metagenome shot-gun sequencing. Mucosal-associated bacteria were quantified with quantitative PCR and visualized by fluorescent in situ hybridization. Tissue cytokines were measured with multiplex arrays and mononuclear phagocyte populations by flow cytometry. RESULTS: Surgery induced microbial functional and taxonomic shifts, decreased diversity, and depleted Bacteroidia and Clostridia. ICR mice had reduced colitis but worse ileitis with bacterial overgrowth, increased translocation, and reduction in tissue macrophages. FMT prevented ileitis but restored colitis and allowed for a bloom of γ-proteobacteria. In the colon, ICR and sham transplant were associated with recruitment of tolerogenic dendritic cells, whereas FMT shifted these immune cell subsets to control profiles along with increasing cytokine levels. CONCLUSIONS: This study suggests that surgical-induced immune dysfunction and microbial dysbiosis with impaired clearance may be the underlying cause of the early ulcerations found in the ileum of patients with Crohn's disease after ICR. FMT has an immunostimulatory effect on the postoperative intestine, which was beneficial in preventing ileitis, but detrimental in restoring colonic injury after surgery.

Ulcerative ileitis after proctocolectomy in children: a complication of ulcerative colitis or a disease in itself after ileoanal pullthrough?

Ulcerative ileitis (UI) after restorative proctocolectomy (RPC) and ileoanal pullthrough procedure (IAPP) is a rare condition described as inflammation of the terminal ileum proximal to the anastomosis. It is mostly observed in ulcerative colitis (UC) and is designated as prepouch ileitis; sometimes with pouchitis, but not necessarily all the time. Its incidence in adults is less than 5%, but the information in children is limited. Pathogenesis is unknown, it has been considered as a disease by itself, independently on the underlying disease. It involves additional morbidity and impacts negatively on quality of life because there is no effective treatment so far. This study aims to review the cases of UI in our institution and to summarize their clinical features and management. A descriptive retrospective study of UI patients between 1990 and 2013 was conducted. Children with RPC and IAPP with clinical and pathological diagnosis of UI were included. Sociodemographic and clinical data, diagnostic, and therapeutic procedures were collected through medical records. UI was diagnosed in eight patients (six males) after RCP; four had UC, two had total colonic aganglionosis (TCA), and two had complex anorectal malformations (one cloacal exstrophy and one omphalopagus twin with bladder exstrophy). Different surgical techniques were used in each case: UC patients underwent IAPP, 50% with J-reservoir and 50% without it; posterior sagittal pullthrough was performed in those with anorectal malformations; one Soave and one Swenson procedure in those with TCA. In summary, three patients had reservoir and five did not. The median age at the IAPP and ostomy closure was 6 years (range 2 months-8 years) and 7 years (range 6 months-9 years), respectively. UI was found after a median of 23 months (range 1-48 months), all of them after digestive tract continuity was reestablished. The leading symptom was lower GI or gastrointestinal, both of them bleeding with abdominal pain, followed by abdominopelvic abscesses and malabsorption with weight loss. Pathology showed nonspecific inflammatory changes. Treatment included antibiotics, corticosteroids and/or immunosuppressive agents with variable response, requiring a new ileostomy in five cases. Ileitis disappeared after diversion. In our experience, UI after colectomy is not an exclusive feature of UC as has been previously described. Although it appears with pouchitis, the presence of a reservoir is not a must, suggesting that this is a different entity. No medical treatment has been really effective in our patients and diversion above this level stopped the process. Further studies on its pathogenesis and treatment strategies are necessary.