Pathogenic Mechanisms in C Diff Infection and Colitis

Study Overview
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Brief Summary
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The purpose of this study is to learn more about infection by Clostridium difficile (also known as C. difficile). C. difficile is a common bacterium (a germ that may cause disease) that can live in the human gut. Some people have it without having any symptoms. In other people it can cause illness ranging from mild diarrhea to severe colitis (infection of the colon). C. difficile makes toxins that damage the cells that line the colon. The study doctors want to find out how these toxins cause damage to the cells in the colon.

Detailed Description
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The purpose of this study is to examine pathogenic mechanisms of Clostridium difficile toxin-mediated intestinal injury and inflammation. Two primary mechanisms will be examined. To examine the hypothesis is that microRNA expression profiles are dysregulated by Clostridium difficile toxin exposure and that dysregulation of miRNA expression plays a role in the pathogenesis of C. difficile associated diseases. To examine the hypothesis is that the TLR9 receptor mediates key inflammatory events in response to Clostridium difficile toxin exposure.

Official Title
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Pathogenic Mechanisms in Clostridium Difficile Infection and Colitis

Conditions
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Clostridium Difficile Infection

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age greater than 18 yrs and less than 75 years Undergoing a clinically indicated colonoscopy Exclusion Criteria: Known, active or recurrent colonic disease including: Clostridium difficile infection, inflammatory bowel disease, microscopic colitis, colon resection for any reason, ischemic colitis, recurrent diverticulitis, colon cancer. Note: Diverticulosis without recurrent diverticulitis, colonic adenomatous or hyperplastic polyps or colonic arteriovenous malformations will not constitute an exclusion Diarrhea (an average of more than 3 bowel movements per day at baseline) Constipation (an average of fewer than 2 bowel movements per week at baseline). Use of systemic steroid or systemic immunosuppressive medication Severe renal impairment Relative contraindication to colon biopsy including a bleeding diathesis or anti-coagulant use. Note: nonsteroidal antiinflammatory drug or asprin use will not constitute a contra-indication.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| All subjects<br> | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Binding of Toxin A (and B) to TLR9 on the human colorectal epithelial cell surface | As assessed by confocal fluorescence microscopy | 24 hours | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| effects of a TLR9 antagonist (ODN-TTAGGG) on toxin binding | The change of mean toxin fluorescence on colonocytes will be measured by confocal microscopy using quantitative image analysis software. | 0 hours | 
| Binding of Toxin A (and B) to TLR9 on the human colorectal epithelial cell surface | as assessed by confocal fluorescence microscopy | 0 hours | 
| Binding of Toxin A (and B) to TLR9 on the human colorectal epithelial cell surface | As assessed by confocal fluorescence microscopy | 6 hours | 
| Effects of a TLR9 antagonist (ODN-TTAGGG) on toxin binding | The change of mean toxin fluorescence on colonocytes will be measured by confocal microscopy using quantitative image analysis software. | 6 hours | 
| Effects of a TLR9 antagonist (ODN-TTAGGG) on toxin binding | The change of mean toxin fluorescence on colonocytes will be measured by confocal microscopy using quantitative image analysis software. | 24 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Clostridium difficile infection