The Interaction Between Intestinal Microbiota, Innate Defense and Epithelial Integrity in the Development of Pouchitis

Study Overview
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Brief Summary
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Pouchitis is a common complication following proctocolectomy with ileal pouch anal anastomosis (IPAA) in patients with ulcerative colitis (UC). It affects the quality of life and can become a chronic problem. The aetiology of pouchitis is not completely understood. A crucial role of the intestinal microbiota has been suggested, but no causative agent has been identified so far. Furthermore, the defensin expression and the epithelial integrity are altered in inflammatory bowel diseases and may play an important role in the development of intestinal inflammation. Therefore, it has been hypothesized that the interaction between an altered microbiota composition, a defective epithelial integrity and changes in innate defense parameters such as defensins has a pivotal role in the development of pouchitis in UC patients.

Official Title
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The Interaction Between the Intestinal Microbiota, Innate Defense and Epithelial Integrity in the Development of Pouchitis: a Multifactorial Approach

Conditions
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Pouchitis

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: patients with ulcerative colitis undergoing a total colectomy with IPAA for steroid dependent disease, therapy-refractory disease, colorectal cancer or severe dysplasia 18-65 years of age Exclusion Criteria: unable to give informed consent pregnant or breastfeeding

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| ulcerative colitis patients with a pouch<br>ulcerative colitis patients undergoing proctocolectomy with an ileal pouch anal anastomosis comparing patients with versus those without pouchitis no intervention | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Differences in the intestinal microbiota composition between pouch patients with and without pouchitis | A phylogenetic microarray will be used to characterize the luminal and mucosal microbiota composition (based on the SSU rRNA gene)of pouch patients with and without pouchitis. Anticipated results are the identification of specific bacterial profiles, genera and/or species dat are discriminating between subgroups. | 24 months. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| The expression of defensins in the intestinal mucosa | The mRNA expression levels of human alfa and beta-defensins in intestinal mucosal biopsies will be assessed by real time PCR | 24 months | 
| The intestinal permeability | The epithelial integrity will be studied by the multiple sugar test to assess small intestinal and whole gut permeability. | 24 months. | 
| Inflammatory mediators | Cytokine levels will be studied in serum and in intestinal biopsies. Furthermore, a histological evaluation and the MPO activity will be studied in these biopsies and calprotectin levels will be determined in 'fecal' sampels. | 24 months | 
| The expression of tight-junction associated proteins | The intestinal tight junctions-associated proteins will be studied by immune staining of intestinal biopsies and mRNA levels in intestinal biopsies using real time PCR. Biopsies will be collected from standardised locations. | 24 months. | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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pouch, pouchitis, ulcerative colitis, microbiota, defensins, epithelial integrity