759 TL1A and DR3 Play a Protective Role Against Intestinal Injury in Dextran Sodium Sulfate (DSS) Colitis

759 TL1A and DR3 Play a Protective Role Against Intestinal Injury in Dextran Sodium Sulfate (DSS) Colitis

760 Divergence in L4 Crohn's Disease: Jejunal, Not Esophagogastroduodenal Involvement, is Protective of L2 Disease Location, and a Risk for Stricturin...

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760 Divergence in L4 Crohn's Disease: Jejunal, Not Esophagogastroduodenal Involvement, is Protective of L2 Disease Location, and a Risk for Stricturing Behavior and Multiple Abdominal Surgeries. Report From the NIDDK-IBDGC Registry Mark Lazarev, Susan Hutfless, Alain Bitton, Judy H. Cho, Richard H. Duerr, Dermot P. McGovern, Deborah D. Proctor, Miguel Regueiro, John D. Rioux, Phil Schumm, Kent D. Taylor, Mark S. Silverberg, Hillary Steinhart, Steven R. Brant Introduction: In the Montreal classification of Crohn's disease (CD) site, L4 includes esophagogastroduodenal (EGD) and jejunal disease. However, it is not clear whether the natural history of jejunal and EGD diseases are similar and should be lumped together, or should be classified separately. Study aims were to compare jejunal, EGD and non-L4 disease (L1, L2, and L3 only) with respect to: 1) ileal/colonic location 2) disease behavior (B1-inflammatory, B2-stricturing, B3-penetrating) 3) the need for one or more abdominal surgeries and 4) smoking history and IBD family history. Methods: The NIDDK-IBD Genetics Consortium has enrolled and phenotyped CD patients (pts) from 7 North American centers since 2003. As of 09/2009, there were 85 pts with L4 limited to jejunum (L4-jej), 137 with L4 limited to EGD (L4-EGD), and 1,344 with non-L4 disease. Univariate analyses used chi-square tests for categorical variables and t-tests for continuous variables. Sex, race, age at diagnosis, duration of disease, disease location, disease behavior, smoking, and IBD family history were adjusted for in multivariate analyses. Odds ratios were determined by logistic regression. Results: 39% of L4-jej pts also had L1 site (ileal) compared to 21% of L4-EGD pts (p=0.03) and 32% of non-L4 pts (p=0.33). 2.4% of L4-jej pts had L2 site (colonic) compared to 20.4% of L4-EGD pts (p=0.006) and 20.5% for non-L4 pts (p<0.001). L3 site (ileocolonic) was not different among groups. 48% of L4-jej pts had B2 behavior, compared to 18% for L4-EGD pts (p<0.001) and 21% for non-L4 pts (p<0.001). There were no differences in B3 behavior among groups (29%, 23%, and 30%, respectively). Frequency of ≥ 1 abdominal surgery was 71% in L4-jej compared to 36% in L4-EGD pts (p=0.004) and 47% in nonL4 pts (p=0.02). Frequency of > 1 abdominal surgery was 40% in L4-jej pts compared to 15% in L4-EGD pts (p=0.002) and 17% in non-L4 pts (p<0.001). There were no differences among groups for smoking or IBD family history. In multivariate analyses, compared to non-L4 disease, L4-Jej was an independent predictor of B2 behavior (OR - 3.3(2.0 - 5.2), p<0.0001) and multiple abdominal surgeries (OR - 3.5 (1.9 - 6.2), p<0.0001). Conclusions: CD pts with L4-jej disease are considerably less likely to have L2 involvement, and more likely to have stricturing disease and multiple abdominal surgeries than either non-L4 or L4-EGD pts. Given the implications for genotype/phenotype correlations, the Montreal classification should separate L4 into two categories: L4 to denote jejunal involvement and a new category, L5, to denote EGD involvement.

758 Innate Immune Cell Dysfunction Leading to Colitis Development Stems From a Loss-of-Function Defect Deanna D. Nguyen, Michelle A. Eston, Scott B. Snapper Background & Aims: Wiskott-Aldrich Syndrome protein (WASP) is an intracellular signaling molecule involved in actin polymerization. WASP deficiency in patients is associated with immunodeficiency and autoimmunity, including colitis. Likewise, WASP knockout (WKO) mice develop spontaneous colitis. WASP/RAG double KO (WRDKO) mice fail to develop colitis indicating that lymphocytes are required for colitis initiation. Chimeric (WTWC) mice, containing wild-type (WT) CD4+ T cells transferred into WRDKO mice, rapidly develop severe colitis indicating the critical importance of WASP-deficient innate immune cells in disease development. How innate immune cell dysfunction can lead to colitis development in the presence of WT T cells is unknown. We aimed to determine whether the defect in WKO innate immune cells leading to colitis in these chimeric mice is dominant and whether T cells in chimeric mice are permanently imprinted to cause disease. Methods: To evaluate whether T cells in WTWC mice are permanently imprinted, we isolated CD4+ cells from these mice and injected them into RAG KO or WRDKO mice in a secondary transfer. To assess effect of Treg pretreatment on subsequent colitis development, WRDKO mice were reconstituted with WT Tregs two weeks before naïve T cell transfer. For BM chimeras, lethally irradiated WT mice were reconstituted with either 100% WRDKO BM or 50% WRDKO BM and 50% RAG KO BM. Five weeks after BM transfer, mice were injected with naïve T cells. All experimental mice were followed for weight changes and histologic colitis scores. Results: WRDKO mice pretreated with WT Tregs did not develop colitis when subsequently reconstituted with naïve T cells compared to mice without pretreatment (average score 0.333 vs 5, p = 0.001). In secondary transfers, WTWC CD4+ T cells did not lead to the severe colitis in RAG KO mice that was observed in WRDKO mice (average score 1.17 vs. 6.8, p = 0.001). Lastly, BM chimeras that received 50% RAG KO BM did not develop colitis, compared to the moderate disease observed in mice that received solely WRDKO BM (average score = 0.8 vs. 3.5, p < 0.001). Thus, colitis in WTWC mice can be prevented by either WT Treg pretreatment or the presence of WASP-sufficient innate immune cells. Conclusions: WT CD4+ T cells are not permanently imprinted to become colitogenic by WKO innate immune cells. The innate immune defect in WTWC mice stems from a loss-of-function defect in WKO innate immune cells since colitis can be prevented by WASPexpressing BM-derived innate immune cells and by Treg pretreatment. These observations may have possible implications on potential therapies for inflammatory bowel disease.

761 The Effect of Perianal Disease on Perceived Severity of Crohn's Disease (CD) Jenna Paterson, Rachel Grafton, Daniel R. Van Langenberg, Jane M. Andrews Introduction: The Crohn's Disease Activity Index (CDAI) assesses current severity of CD. Perianal Disease (PAD) is scored using the Perianal Disease Activity Index (PDAI). Little evidence exists to show the relationship between the two indices. Hence we examined this, hypothesising that patients with a higher PDAI will have a higher CDAI. We additionally sought to determine whether PAD in itself, or complex PAD, conferred any additional burden in terms of quality of life (QoL) or psychological co-morbidity. Methods: All Inflammatory Bowel Disease (IBD) patients attending a metropolitan hospital were prospectively identified over a six month period via ICD-10 coding. Each was surveyed regarding disease, psychological measures (Hospital Anxiety & Depression Scale [HADS]) and QoL (short Inflammatory Bowel Disease Questionnaire [SIBDQ]). The CDAI was estimated from contemporaneous case notes entries. The activity of any PAD was scored using the PDAI. Results: The survey yielded 60% response rate and no significant demographic or clinical differences were noted in responders vs. non-responders (data reported ECCO 2009). There were 95 CD patients, 66 with no PAD, and 28 with PAD. Amongst those with PAD, 10 had Complex PAD whereas 18 had simple PAD (skin tags, anal fissures, mucosal tears). The most striking finding was the absence of any correlation between PDAI and CDAI scores (r2 = 0.003, p=NS). This was true regardless of whether patients had complex PAD or simple PAD (r2 = 0.035 and 0.087 respectively). Unexpectedly, the mean scores for anxiety and depression did not differ between those with and without PAD (7.21 vs 7.72 p=0.59 & 5.25 vs 5.91 respectively p= 0.46), nor did the proportion of patients with likely anxiety or depression (score >7) differ between those with and without PAD (54% vs 61% p=0.50; 29% vs 42% p=0.26). Consistent with this, we found no difference in QoL between those with and without PAD (mean SIBDQ 43.50 vs.43.75, p=0.93). This lack of difference in SIBDQ held even when only those with complex PAD were considered (complex 43.60, simple 43.44, no PAD 43.75) although the median SIBDQ score appeared marginally lower in those with complex PAD (complex 43.00; simple 46.00, no PAD 45.00). Conclusion: The data clearly show there is no correlation between CDAI and PDAI, making CDAI an incomplete measure of the global burden in CD. However, somewhat surprisingly, PAD of its own does not appear to be an independent predictor of poorer psychological outcomes. Due to the cross sectional nature of the data and small sample size, these results warrant confirmation in a larger independent cohort.

759 TL1A and DR3 Play a Protective Role Against Intestinal Injury in Dextran Sodium Sulfate (DSS) Colitis Li-Guo Jia, Mitchell Guanzon, Eddie C. Wang, Fabio Cominelli Background/Aims: There is increasing evidence that “innate cytokines,” such as TNF-alpha may have a protective role in gut homeostasis and acute intestinal injury. These effects are in contrast to their pro-inflammatory actions during chronic intestinal inflammation. The role of other TNF superfamily members, such as TL1A/DR3, in this process is unknown. The aim of this study was to determine the effects of DR3 deletion in the acute and recovery phases of DSS-induced colitis. Methods: Acute colitis was induced by 7 days of 3% DSS administration in drinking water to DR3 knock out (KO) mice and wild type (wt) controls. On day 7 after DSS administration (acute phase), mice were sacrificed and intestinal tissues collected for histological and biochemical analyses of intestinal inflammation. A different group of mice was given 7 days of DSS followed by drinking water for 14 days (recovery phase). On day 21, mice were sacrificed for tissue collection and analysis of intestinal inflammation. Quantitative RT-PCR was used for measuring mRNA expression of colonic TL1A, IFN-gamma, TNF-alpha, IL17 and IL10. Results: DR3 KO mice (n=12) had significantly more fecal bleeding compared to DR3 wt mice (n=12) (6.6+1.2 vs 2.8+0.7, p< 0.01). Histological inflammatory scores were also higher in DR3 KO mice (n=6) compared to DR3 Wt mice (n=7) (8.0+1.7 vs 4.4+1.7, p=0.08). Survival rates of mice after DSS administration were 39% for DR3 KO and 66.6% for DR3 wt, respectively (p<0.05). Interestingly, basal mRNA levels (no-DSS) of colonic IFN-gamma, TNF-alpha and IL10 were significantly elevated in DR3 KO mice compared to DR3 wt mice (p<0.01). No significant differences in cytokine mRNA expression were observed in DR3 KO mice compared to DR3 wt mice during the acute phase. By comparison, colonic mRNA levels of TNF-alpha, IL17 and IL10 were significantly increased in DR3 KO mice compared to DR3 wt mice in the recovery phase (8-21-fold increase, p<0.01). Conclusions: DR3 KO mice are more susceptible to intestinal injury compared to DR3 wt mice, both in the acute and recovery phases of DSS colitis. Increased production of proinflammatory cytokines in DR3 KO mice may contribute to these effects. Our results suggest a novel protective function of TL1A/DR3 in gut homeostasis and response to acute intestinal injury.

762 The Association Between IBD and Venous Thromboembolism in Danish Children and Adults: A Population-Based Case-Control Study Michael Kappelman, Erzsebet Horvath-Puho, Robert S. Sandler, David T. Rubin, Thomas A. Ullman, Lars Pedersen, John A. Baron, Henrik T. Sorensen Background: An association between inflammatory bowel disease (IBD) and venous thromboembolic events, including deep venous thrombosis (DVT) and pulmonary embolism (PE), has long been suggested by case reports and clinical experience. However, results of population-based epidemiological studies are conflicting. The extent to which this risk varies

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AGA Abstracts

AGA Abstracts

XBP1 (sXBP1) transcript levels (relative fold increase 85, 31, 60 and 29) in CD8αβ+ IEL but not in CD8αα+ IEL or LPL. Chromatin immunoprecipitation (CHIP) analysis from splenic CD8αβ T cells from TNF△ARE/+ but not wild type mice revealed selective recruitment of ATF6 and XBP1 to the Grp78 promoter. Consistent with the cytotoxic effect of TNF△ARE/ + derived CD8αβ+ T cells on the small intestinal epithelial cell line Mode-K, CHIP analysis revealed selective binding of ATF4, ATF6 and XBP1 to the granzyme B promoter in CD8αβ+ IEL from TNF△ARE/+ but not wild type mice. Finally, Grp78 knock down through the use of siRNA or the bacterial toxin EGF-SubA fusion protein completely abolished IFNγ and granzyme B expression. In conclusion, these results provide first evidence that ER stress response-associated mechanisms contribute to the cytotoxic effector function of CD8αβ+ IEL under condition of chronic ileitis in TNF△ARE/+ mice.