AGA Abstracts compared to 22% of ASF/Hp infected mice and 33% Hp infected SPF mice. ASF/Hp infected mice had their gastric contents colonized with the 3 species of ASF when measured by qPCR. Our data demonstrates that specific enteric flora colonizing the achlorhydric stomach enhances progression of gastric cancer development. 60 Bone Marrow-Derived Cells or Gastric Epithelial Cells? Both Contribute to the Development of Gastric Cancer in Helicobacter pylori-Infected Mice Songhua Zhang, Woojin Kim, Arlin B. Rogers, Jessica Faiz, Victoria Ruiz, Sicheng Wen, Jean Marie Houghton, Steven F. Moss Chronic Helicobacter pylori (H. pylori) infection promotes the development of non-cardiac gastric carcinoma in humans. This is modeled by prolonged H. pylori SS-1 infection in p27- knockout (p27KO) mice, resulting in gastric neoplasia. Bone marrow derived mesenchymal cells (BMDC) have been shown to contribute to the development of gastric cancer in Helicobacter-infected C57BL/6 mice. Aim: To determine whether the increased susceptibility to gastric carcinogenesis of p27KO mice is dependent upon their p27-null bone marrow- derived cells or upon their p27-null gastric epithelial cells. Methods: Female p27KO and wild type (WT) C57BL/6 mice were irradiated and transplanted with bone marrow (BM) from male GFP-transgenic WT or p27KO mice respectively. Female WT mice that received BM cells from male GFP-transgenic WT mice served as controls. All recipient mice were euthanized one year after H. pylori SS-1 infection. H. pylori status was evaluated by serology, culture and PCR, and gastric tissue was harvested for histology, immunostaining and Y- chromosome fluorescent in situ hybridization (FISH). Results: BM cells in the stomach were successfully detected by Y-chromosome FISH and/or anti-GFP immunostaining. Immuno- fluorescence staining of glandular progenitor/stem cell markers (DCAMKL-1 and Lgr-5) demonstrated co-staining in GFP-positive BM cells in dysplastic gastric glands. WT mice that received BM from GFP-transgenic WT mice (WT→WT) did not develop dysplasia/ neoplasia whereas the other two groups (WT BM→p27KO or p27KO BM→WT) developed advanced gastric pathology, including high-grade dysplasia. There were no statistical differ- ences in histology scores between the two p27 mismatched groups (WT BM→p27KO and p27KO BM→WT); both these groups had significantly increased scores of overall pathology (p<0.05 for p27KO BM→WT vs controls, p<0.01 for WT BM→p27KO vs controls), inflam- mation (p<0.01), epithelial defects (p<0.01), oxyntic atrophy (p<0.01) and hyperplasia (p<0.01) compared with WT→WT controls. Additionally, WT BM→p27KO mice had higher scores for pyloric metaplasia (p<0.05) and dysplasia (p<0.01) compared with WT→WT controls whereas differences between the p27KO BM→WT and WT→WT controls did not reach statistical significance. Finally, mice in the WT BM→p27KO had significantly poorer overall survival rates (0% survival at 48 weeks, versus 74% in the p27KO BM→WT group and 100% for WT→WT controls, p<0.0001, for WT BM→p27KO versus each of the other two groups, see figure). Conclusion: Irradiation and BMT does not itself cause significant damage to the gastric mucosa. Both bone marrow-derived and gastric epithelial cells contrib- ute to the increased gastric cancer susceptibility of p27-deficient H. pylori-infected mice. Kaplan-Meier Survival Curve 61 HLA DQ2/8 Prevalence in Non-Celiac Patients With Gastrointestinal Diseases Daniel DiGiacomo, Antonella Santonicola, Ilaria Russo, Fabiana Zingone, Edoardo Troncone, Maria Cristina Caria, Patrizia Borgheresi, Adele Fortunato, Serena Gallotta, Carolina Ciacci Background: The human leukocyte antigen (HLA) class II is frequently implicated in increased autoimmune disease risk varying across geographic regions. Thus there is value in investiga- ting HLA allele distribution and its association with disease risk on a micro level. The aim of this study was to define the prevalence of HLA DQ 2/8 alleles in a Southern Italian non- celiac GI ambulatory clinic population and to determine if specific HLA DQ2/8 alleles were associated and/or predictive of GI/liver disease risk. Methods: 450 patients were recruited over a period of 3 months from 3 gastroenterology ambulatory clinics of Campania Region, Italy. Demographics, disease history and current GI symptoms/a-tTg levels were recorded. Disease status was classified according to the nature of presenting problem. Separate categories were attributed generally to liver disease/transplant (P1), esophageal/gastric (P2), lower functional (P3) and inflammatory GI (P4). Those with IBS/IBD were also tested as a combined group (P5) to increase the power of comparisons. Results: From the patients included in our analysis 202/452 (44.89%, 95%CI 40.00%-49.29%) were considered to be HLA DQ2/ 8 positive regardless of disease status. Overall population median age was 56 with 55.56% S-16 AGA Abstracts being female; neither subject's gender nor age differed significantly by HLA DQ2/8 positivity. Within those who were positive 46/202 (22.89%) belonged to the HLA DQ2/β2 homozygous high celiac disease risk group, 40/202 (19.90%) to HLA DQ2 Cis, 17/202 (8.46%) to DQ2 Trans, and nearly half, 86/202 (42.79%), to the low risk DQ8/β2 heterozygous group. 12/ 202 (5.97%) of subjects had genotypes belonging to other alleles. When stratifying by disease group type we found that 86/188 (45.74%) of those with liver disease were HLA DQ2/8 positive, 63/120 (52.50%) with upper GI issues positive, 39/106 (36.79%) of patients with lower functional and 14/36 (38.89%) of those with inflammatory GI disease HLA DQ 2/8 positive. These differences were not significant (P=0.1024). After combining P3+P4 into a single group (P5) a significant negative association was found between those with IBS/IBD vs. upper GI maladies in terms of HLA DQ2/8 positivity (OR=0.539, 0.328-0.883). No a- tTg positive patients were found in the P1 and P4 group. 2/104 (1.89%) of subjects with upper GI issues and 4/91 (4.21%) with lower functional syndrome were found to be a-tTG positive (P=0.0348). Conclusion: Those with esophageal or gastric diseases have more individuals that are HLA DQ2/8 positive compared to those with other GI disorders, outside of celiac disease. Unveiling unknown associations between digestive diseases and class II alleles has the potential to further the understanding of the elusive etiologies of digestive dis- eases. 62 Molecular Alterations in Dysplastic Hamartomas of Peutz-Jeghers Syndrome Patients Susanne E. Korsse, Katharina Biermann, Johan Offerhaus, Elisabeth M. Mathus-Vliegen, Ernst J. Kuipers, Monique van Leerdam, Wendy van Veelen Introduction: Peutz-Jeghers syndrome (PJS) is a rare disease, caused by mutations in the LKB1 tumour suppressor gene. Patients develop multiple hamartomas throughout the gastro- intestinal tract. Although PJS hamartomas are not considered premalignant lesions, neoplastic changes in hamartomas have been described. However, little is known about the molecular changes involved in this process. The aim of this study was to investigate alterations of candidate genes and molecular pathways possibly involved in neoplastic changes in Peutz- Jeghers hamartomas. Methods: Cases were selected from electronic pathology reports of PJS patients from two academic hospitals. All patients had a definite diagnosis of PJS, defined by diagnostic criteria recommended by the WHO, a proven LKB1 mutation, or both. Hamartomas were revised by 2 pathologists, who classified the dysplastic lesions as low grade dysplasia (LGD), high grade dysplasia (HGD), or cancer. FFPE tissue slides were immunostained for αSMA, mib1, β-catenin, P53, phospho-S6 (a downstream target of mTOR), and SMAD4. In addition, somatic mutation analyses for BRAF, KRAS, and P53 were performed on DNA isolated from dysplastic and non-dysplastic areas of hamartomas separately. Results: Of 792 hamartomas of 53 PJS patients (26 males), 11 hamartomas (1.4%) of 9 patients (8 males, median age at diagnosis 35 years) showed dysplasia (Table). All 11 hamartomas showed the characteristic αSMA positive smooth muscle bundles, inde- pendent of the presence or grade of dysplasia. All dysplastic lesions showed increased proliferation as compared to the non-dysplastic epithelial areas. Of 9 hamartomas with dysplasia, FFPE tissue was available for molecular analysis. Nuclear expression of β-catenin was seen in the dysplastic epithelium of 4/9 (44%) hamartomas, all with LGD. Overexpression of P53 was observed in 3/9 (33%) hamartomas, all with HGD/adenocarcinoma. The fourth hamartoma with HGD showed complete absence of P53 expression. Two hamartomas (22%), one with HGD and one with adenocarcinoma, were negative for nuclear SMAD4 expression. Increased levels of pS6 could be observed in the dysplastic epithelium and the surrounding stroma of all hamartomas, but was most pronounced in the HGD foci. Mutation and LOH analyses are in progress. Conclusion: Although dysplasia in PJS hamartomas is rare, it is accompanied by molecular changes in genes and pathways involved in intestinal cancer development. The association between HGD and alterations in P53 expression and loss of nuclear SMAD4 suggest that loss of function of P53 and TGFβ/BMP signaling is involved in neoplastic changes in PJS hamartomas. Furthermore, hamartomatous-dysplastic epithelial changes seem to be associated with activation of the mTOR pathway. Characteristics of dysplastic Peutz-Jeghers hamartomas 63 A Novel Cluster of Patients With Familial Mediterranean Fever (FMF) Displayed Abnormal Gastrointestinal Motorfunction Piero Portincasa, Valentina Ruggiero, Leonilde Bonfrate, Giuseppe Scaccianoce, Donato Piglionica, David Q. Wang, Giuseppe Palasciano FMF is a rare autosomal recessive autoinflammatory disorder characterized by recurrent febrile attacks and severe abdominal pain due to serositis. The FMF gene (MEFV, cr16p ) encodes a 781 aa. protein (pyrin or marenostrin), a regulator of the inflammatory cascade. Over 60 MEFV mutations have been identified, and colchicine prevents painful attacks and secondary amyloidosis. We recently identified a novel cluster of FMF patients living in the proximity of Bari (Southern Italy). Aim and Methods: As abdominal symptoms are the most prevalent feature of FMF, we investigated GI motility in 28 patients (M:F=12:16; age 39±3 SEM yrs) with the following mutations (DNA analysis of MEFV entire coding region): E148Q/