Current Projects

The IBDGC serves the scientific community by advancing the genetic and clinical knowledge of Crohn’s disease and Ulcerative Colitis. We are defining the pathogenesis of IBD through genetic approaches, the utilization of large collaborative datasets, the judicious use of a variety of study populations, a strong cross-disciplinary approach, uniform and clearly defined phenotype criteria, and a strong management and organizational structure.

Ileal Resection for Crohn’s Disease

Study Title: Mechanisms of intestinal inflammation following ileal resection for Crohn’s Disease

We are currently recruiting for a multi-center Crohn’s Disease study. The purpose of this study is to gain further understanding of the mechanisms involved in the recurrence of inflammation following ileal resection surgery for Crohn’s disease (CD). One of the most common locations of CD involvement is the end of the small intestine (ileum), up to 70% of CD patients require surgical resections due to disease at this location. Such surgical management is often a temporary solution as more than 50% of these patients experience recurrence of inflammation one year post surgery, and 90% at five to 10 years following surgery. Reasons for this recurrence remain unknown, however it is believed to be caused by an interaction of genetic, immune and microbial features.

We are conducting analyses on blood, surgical tissue, stool and intestinal biopsy. Studying the IBD specific inflammation, which is localized to the intestine, will lead to a better understanding of the pathways important for intestinal immune system regulation. The complexity of IBD is based on the working belief that gastrointestinal inflammation is a result of an unregulated response of the immune system to intestinal bacteria, which we will be able to study with biopsies and stool. Information gained from this study will be used to build a predictive model to identify those patients at greater risk of rapid recurrence, and will aid physicians in tailoring follow-up treatments.

If you are scheduled to undergo or recently underwent an ileal resection surgery for treatment of your Crohn’s, and are interested in participating in this study, contact the IBDGC genetic research center closest to you.

If you are a clinician and would like to participate as a satellite recruitment center please contact Yashoda Sharma .

Across the Biologic Demarcation of Ulcerative Colitis

Study Title: Mechanisms of microbiota in mucosal inflammation across the biologic demarcation of Ulcerative Colitis

The long-term purpose of this study is to increase knowledge about IBD to better understand its causes and improve diagnosis, treatment, or even prevention. The immediate objective is to gain further understanding of the mechanisms involved in the susceptibility to and flare of inflammation in UC patients, by evaluating the genetic, microbial, gene expression and serological factors associated with mucosal inflammation. For this study, we will collect mucosal lavage (a solution which bathes the mucosal surface), mucosal biopsy (a small piece of tissue taken from the mucosal surface), blood, saliva, and stool samples from UC individuals. For mucosal lavage, saliva, and stool samples, microbial studies will be carried out to identify the bacteria associated with IBD. Additional studies will be carried out to understand the interaction between the bacteria and the host.

We believe the information we get from this project will help understand the role of intestinal bacteria in UC initiation and development, identify the specific bacteria, metabolites, and proteins associated with UC, and how the host effectively responds as a whole.

If you have been diagnosed with UC, and are interested in participating in this study, contact the IBDGC genetic research center closest to you.

If you are a clinician and would like to participate as a satellite recruitment center please contact Yashoda Sharma .

African American GWAS

Crohn’s disease incidence in African Americans (AA) is similar to that of white Americans, although population based prevalence lags behind. In one population study the ratio of CD incident cases was 1.6 fold that of UC, whereas in white, the ratio was 0.9. This suggests that there might be unique ancestral risk factors in AA CD. Additionally, the NIDDK IBDGC discovered that AA had significantly greater risk of colon-only and perianal disease location, and greater risk of uveitis and spondyloarthritis. We propose a two-stage, high risk locus discovery CD GWAS in the African American population.

Along with Subra Kugathasan at Emory University and additional collaborators at the University of Washington, we will genotype 500 CD cases using the Illumina Omni2.5 platform and compare with data on 2500 AA controls. A replication study on 1000 of the highest SNPs will be performed in 500 cases comparing with 2500 additional AA controls from dbGAP.

If you are of African American heritage and have been diagnosed with CD or UC, and are interested in participating in this or future studies, contact the IBDGC genetic research center closest to you.

If you are a clinician and would like to participate as a satellite recruitment center please contact Yashoda Sharma .

Exome Chip

The exome chip was developed with Illumina to capture genetic variants identified in exome sequencing experiments. The chip contains about 271,453 SNPs, and an additional 30,000 beadtypes of custom content. The Cedars, Pittsburgh and MSSM GRCs added custom content for Ashkenazi Jewish IBD and from unpublished sequencing experiments. Genotyping was completed on ≈ 25,000 subjects. Two studies resulted from this collaboration, and manuscripts will be submitted for publication.