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Dynamic Regulation of Intestinal Crypt Base Columnar Stem Cells by NotchSignalingAlexis J. Carulli, Gail B. Gifford, Wenli Liu, Linda C. Samuelson

Background/Aim: The intestinal epithelium is a rapidly renewed tissue, requiring continualreplenishment by intestinal stem cells (ISCs) in order to sustain life. The crypt base columnarcell (CBC) is an actively dividing ISC population marked by the expression of Lgr5, Ascl2,and Olfm4. Our recent studies show that Notch signaling regulates epithelial cell homeostasisby directing differentiated cell fate and promoting stem cell maintenance. In this study weexamined Notch regulation of CBCs by characterizing Olfm4 expression and function.Methods: Gamma-secretase inhibitors (GSIs) were used to block Notch signaling in C57BL/6 mice (30μmol/kg dibenzazepine; DBZ) or in the human colon cancer cell line LS174T(40μM DAPT). Tissue was analyzed at various time points for progenitor and differentiatedmarker expression and epithelial proliferation by histological staining and qRT-PCR. LS174Tcells were used to investigate the mechanism of Notch regulation of Olfm4 expression.Genetically engineered Olfm4-deficient mouse intestine was studied to examine the functionof this CBC marker for intestinal epithelial cell homeostasis. Results: Chronic Notch inhibi-tion for 6 days resulted in marked secretory cell hyperplasia, decreased cellular proliferation,and a striking decrease in Olfm4 mRNA, showing that Notch is critical for many differentaspects of cellular renewal. Surprisingly, acute block of Notch with a single dose of DBZwas sufficient to cause a rapid and transient loss of Olfm4, in addition to a delayed, yetsustained surge in secretory cells and cellular proliferation. This surge in proliferation wasin stark contrast to the loss of proliferation observed with chronic DBZ treatment. The acuteDBZ model revealed exquisite Olfm4 regulation: mice treated with one dose showed asignificant decrease in Olfm4 mRNA within 12 hours, but recovery to baseline within 2days. Similarly, LS174T colon cancer cells showed decreased Olfm4 mRNA 4 hours afterDAPT administration. To test whether changes in Olfm4 expression may mediate Notcheffects in the intestine we examinedOlfm4-/- mice. This analysis showed normal proliferation,cell fate, and CBC marker gene expression patterns, demonstrating that Olfm4 is not requiredfor CBC function. However, we observed expression of other Olfactomedin family membersin intestine, suggesting functional redundancy.Conclusions:Olfm4 is dynamically regulatedby Notch signaling, with rapid loss of transcripts observed upon acute Notch inhibition.Thus this CBC marker is a sensitive read out of Notch activity in the intestine. Olfm4-/-mice did not exhibit an intestinal phenotype, although related family members may play acompensatory role, suggesting compound mouse mutants may be needed to understand thefunction of Notch regulation of Olfm4 in the CBC.

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High Altitude Journeys and Flights are Associated With the Increased Risk ofFlares in IBD PatientsStephan R. Vavricka, Gerhard Rogler, Sandra Maetzler, Benjamin Misselwitz, Christine N.Manser, Kacper A. Wojtal, Alain Schoepfer

Background: There is increasing experimental evidence that hypoxia induces inflammationin the gastrointestinal tract. Hypoxia-inducible transcription factor (HIF)-1α influencesadaptive immunity and has been shown to induce barrier-protective genes in the case ofexperimentally-induced colitis. The clinical impact of hypoxia in patients with inflammatorybowel disease (IBD) is so far poorly investigated. Aim: We wanted to evaluate if flights andjourneys to regions ≥2000 meter above sea level are associated with the occurrence of flaresin IBD patients in the following 4 weeks. Methods: A questionnaire was completed byinpatients and outpatients of the IBD clinics of three tertiary referral centers presenting withan IBD flare in the period from Sept 1st 2009 to August 31st 2010. Patients were inquiredabout their habits in the 4 weeks prior to the flare. Patients with flares were matched withan IBD group in remission during the observation period (according to age, gender, smokinghabits, and medication). Results: A total of 103 IBD patients were included (43 Crohn'sdisease (CD), whereof 65% female, 60 ulcerative colitis, whereof 47% female, mean age39.3±14.6 years for CD and 43.1±14.2 years for UC). Fifty-two patients with flares werematched to 51 patients without flare. Overall, IBD-patients with flares had significantly morefrequently a flight and/or journey to regions ≥ 2000 meters above sea level in the observationperiod compared to the patients in remission (21/52 (40.4%) vs. 8/51 (15.7%), p=0.005).There was a statistically significant correlation between the occurrence of a flare and a flightand/or journey to regions ≥ 2000 meters above sea level among CD patients with flares ascompared to CD patients in remission (8/21 (38.1%) vs. 2/22 (9.1%), p=0.024). A trendfor more frequent flights and high-altitude journeys was observed in UC patients with flares(13/31 (41.9%) vs. 6/29 (20.7%), p=0.077). Mean flight duration was 5.8±4.3 hours. Thegroups were controlled for the following factors (always flare group cited first): age (39.6±13.4vs. 43.5±14.6, p=0.102), smoking (16/52 vs. 10/51, p=0.120), regular sports activities (32/52 vs. 33/51, p=0.739), treatment with antibiotics in the 4 weeks before flare (8/52 vs. 7/51, p=0.811), NSAID intake (12/52 vs. 7/51, p=0.221), frequency of chronic obstructivepulmonary disease (both groups 0) and oxygen therapy (both groups 0). Conclusion: IBDpatients with a flare had significantly more frequent flights and/or high-altitude journeyswithin four weeks prior to the IBD flare compared to the group that was in remission. Weconclude that flights and stays in high altitude are a risk factor for IBD flares.

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In Vitro Fertilization in Patients With Ulcerative Colitis and Ileal Pouch AnalAnastomosisVikas Pabby, Sveta Shah, Adam S. Cheifetz, Robert Burakoff, Sonia Friedman

Introduction Ulcerative colitis (UC) affects many women of reproductive age, raising thequestion of the effects of this disease on fertility. Current evidence suggests that the rate ofinfertility is three-fold higher in women following ileal pouch anal anastomosis (IPAA), aneffect thought to be secondary to tubal adhesions from pelvic surgery. There have been nopublished studies on the efficacy of IVF in patients with UC and IPAA. This study seeks toassess the success rate of In Vitro fertilization (IVF) in patients with UC after IPAA compared

S-68AGA Abstracts

to IVF in the general population. Methods Patients with UC from two tertiary care medicalcenters were identified via ICD 9 codes (556.x) and cross-referenced with those presentingfor IVF between 1998 and 2011. A retrospective chart review was conducted to identifyUC patients who had undergone IPAA. Of these patients, the outcome of each IVF cyclewas determined and the live birth rate was compared to that of IVF in the general population.Results Sixteen patients with a history of IPAA who presented for IVF were identified. Table1 lists characteristics of this population. 15/16 patients had pancolitis prior to surgery andone patient had left-sided colitis. 14/16 patients were non-smokers; 2/16 were former smokersat the time of IVF. 10/16 patients (62.5%) had at least one live birth as a result of IVF.This cumulative live birth rate of 62.5% is comparable to that of 51-72% among 6164patients in a previously published study (Malizia, B et al, NEJM, 2009;360:236-43), thecharacteristics for which are given in Table 1. The 16 patients had a total of 55 cycles; ofthese, the number of IVF cycles resulting in live births was 12 (or 21.8%). This live birthrate per cycle of 21.8% is comparable to reported live birth rates per cycle at Massachusettstertiary care centers, as reported by the Centers for Disease Control, which are 18-26% forfemales aged 38 to 40 and 25-38% for females aged 35 to 37. One patient (6.3%) is currently7 months pregnant as a result of IVF. 4/16 patients (25%) failed IVF, meaning there wasno chemical or clinical pregnancy from any cycle. One patient (6.3%) had failed IVF, butsubsequently had a spontaneous pregnancy. 10/12 live births were by cesarean section.Conclusion Our study demonstrates that the IVF success rate in this cohort is similar tothat of the general population. Therefore, despite the substantial decrease in fertility associatedwith IPAA, these patients can still achieve fertility rates similar to those of the generalIVF population.

Table 1: Characteristics of Patients Presenting for IVF in the IPAA Population and theGeneral Population

Table 2: Outcomes of IPAA Patients Presenting for IVF

305

IBD or IBS: Pain in Quiescent Ulcerative ColitisMatthew Coates, Mayank Lahoti, David G. Binion, Miguel Regueiro, Klaus Bielefeldt

BACKGROUND: Chronic pain is common in inflammatory bowel disease (IBD) patients.Pain may be secondary to inflammation, but many IBD patients without evidence of activedisease also have pain. The aims of this study were to 1) determine the prevalence of painin ulcerative colitis (UC) patients and 2) examine the role of inflammation and psychiatriccomorbidities in UC patients with pain. METHODS: We performed a retrospective cross-sectional analysis of adult UC patients seen at a tertiary referral IBD center between 2007and 2011. Age, gender, disease duration, disease extent, subjective pain rating (based onthe SIBDQ pain score), quality of life (SIBDQ), physician rating of disease severity, endoscopicand histologic rating of disease severity, C reactive protein (CRP) and erythrocyte sedimenta-tion rate (ESR) were abstracted. RESULTS: 607 UC patients were identified: 287 females(f),320 males(m). Using univariate analysis, gender (P<0.01), physician rating (P<0.01), SIBDQ(P<0.01), endoscopic (P<0.01) and histologic (P<0.05) severity rating and ESR (P<0.05)correlated with pain. The disease was considered to be quiescent in 369 (61%; 218 m)patients with 62 (17%) individuals complaining about at least moderate pain, operationallydefined as a pain score of 4 or less. Univariate analysis identified only female sex (P<0.05)as a predictor of pain. We separately compared subgroups of patients without any pain (n=182; 113m) and those with at least moderate pain (n=89; 39m). Patients with pain wereyounger (P<0.05), more likely to be female (P<0.01), had higher endoscopic (P<0.01) andhistologic severity ratings (P<0.05), had higher CRP values (P<0.05), were more likelyto carry the diagnosis of an affective spectrum disorder (P<0.05) and and/or to receiveantidepressants (P<0.001) and opioids (P<0.05). SUMMARY AND CONCLUSIONS: Abdom-inal pain is a common symptom in UC patients in remission. Unrecognized inflammationmay contribute to development of pain in some members of this population. However, theskewed gender distribution and correlation with affective spectrum disorders demonstratedin this study have significant parallels with functional disorders and suggest an importantrole for central mechanisms. Overall, these findings suggest that UC patients with painshould be evaluated for active inflammation, even when their disease is considered to bein remission. In the absence of ongoing inflammation, however, management strategiesshould include consideration of interventions that target affective spectrum disorders andfunctional bowel disorders. Supported by NIH grant DK063922.

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Patient Preferences for Surgical and Pharmaceutical Treatment of UlcerativeColitis: When is Surgery Better Than Drugs?Meenakshi Bewtra, Vikram Kilambi, Corey A. Siegel, James D. Lewis, F. Reed Johnson

BACKGROUND: Treatment options for mesalamine-refractory ulcerative colitis (UC) includechronic immunosuppressive medications or surgery. Current treatment paradigms exhaustall medical therapy and regard surgery as a consequence of medication failure. However,immunosuppressive therapy may not be ideal for all patients due to unclear durable efficacyand potential serious adverse events. While current practice views surgery as an option of