Orla F. Craig

Diagnostic Accuracy of Computed Tomography Using Lower Doses of Radiation for Patients With Crohn's Disease

BACKGROUND & AIMS Magnetic resonance and ultrasonography have increasing roles in the initial diagnosis of Crohns disease, but computed tomography (CT) with positive oral contrast agents is most frequently used to identify those with acute extramural complications. However, CT involves exposure of patients to radiation. We prospectively compared the diagnostic accuracy of low-dose CT (at a dose comparable to that used to obtain an abdominal radiograph) with conventional-dose CT in patients with active Crohns disease. METHODS Low and conventional dose CT of the abdomen and pelvis were acquired from 50 patients with Crohns disease, referred from an inflammatory bowel disease service (20 male; median age, 34 years). Acute complications of Crohns disease were suspected. Iterative reconstruction was performed on all CT datasets to facilitate dose reduction. Three radiologists reviewed the low-dose CT images before the conventional-dose CT images. RESULTS The median effective dose (interquartile range) of radiation for the low-dose CT was reduced by 72% from that of conventional CT: from 3.5 mSv (3-5.08 mSv) to 0.98 mSv (0.77-1.42 mSv) (P < .001). As expected, the quality indexes of the low-dose images were inferior to those of the conventional-dose images, but no clinically significant diagnostic findings were missed with low-dose imaging. Follow-up CT examinations were recommended for 5 patients; 1 had a cervical tumor, 1 had a pancreatic lesion, and 3 had intra-abdominal abscess. In each case, the image obtained by low-dose CT was considered sufficient for diagnosis. CONCLUSIONS Although low-dose CT images are of lower quality than images obtained with conventional doses of radiation, no clinically significant diagnostic findings were missed from low-dose CT images of patients with Crohns disease. The low-dose CT was obtained at a median effective dose equivalent to 1.4 abdominal radiographs.

Current and emerging therapies for the management of functional gastrointestinal disorders

The functional gastrointestinal disorders are common disorders that are associated with significant quality-of-life impairment and considerable economic burden on the healthcare system. They are frequently associated with a comorbid psychiatric condition; this, together with a striking lack of effective pharmacological therapies, means they represent a considerable therapeutic challenge to the treating physician. In this overview, we examine the evidence to support the use of agents currently used in the management of the more common functional gastrointestinal disorders and review emerging therapies.

Bacteria, genetics and irritable bowel syndrome

Evaluation of: Villani AC, Lemire M, Thabane M et al. Genetic risk factors for post-infectious irritable bowel syndrome following a waterborne outbreak of gastroenteritis. Gastroenterology 138, 1502–1513 (2010). While the pathogenesis of irritable bowel syndrome (IBS) remains to be fully defined, two clinical observations – the occurrence, de novo, of IBS following bacterial gastroenteritis and the history, commonly obtained from IBS patients, of other instances of the syndrome within their families – have instigated investigations, in IBS, of the potential roles, on the one hand, of the gut microbiota and the host response and, on the other hand, of genetic factors. The study reviewed here relates to both of these factors by studying genetic predisposition to postinfective IBS in a large population of individuals who were exposed to a multimicrobial enteric infection, which resulted in a severe outbreak of gastroenteritis and was followed by the development of IBS in over a third. In this detailed study, the investigators identified a number of genes that were linked significantly to the development of postinfectious-IBS in the Toll-like receptor 9, IL-6 and cadherin 1 regions. These genes play important roles in bacterial recognition, the inflammatory response and epithelial integrity, respectively, and provide considerable support for the hypothesis that links IBS onset to disturbances in the microbiota and the host response.

Functional dyspepsia: eosinophils, macrophages, and the postinfectious state.

Faten Aberra, Philadelphia, PA Nuzhat A. Ahmad, Philadelphia, PA Hans-Dieter Allescher, GermischPartenkirchen, Germany Jordi Bruix, Barcelona, Spain Lin Chang, Los Angeles, CA William Chey, Ann Arbor, MI Tsutomu Chiba, Kyoto, Japan Massimo Colombo, Milan, Italy Marcia Cruz-Corra, San Juan, PR Jason Dominitz, Seattle, WA James Farrell, Los Angeles, CA Lauren B. Gerson, Stanford, CA W. Ray Kim, Rochester, MN George Lau, Hong Kong, China Joseph M. Llovet, New York, NY Peter Mannon, Birmingham, AL Julian Panes, Barcelona, Spain Eamonn Quigley, Cork, Ireland Shiv K. Sarin, New Delhi, India Shamita B. Shah, Stanford, CA Nathan Subramaniam, Brisbane, Australia George Triadafilopoulos, Stanford, CA Kenneth K. Wang, Rochester, MN Thomas D. Wang, Ann Arbor, MI Alastair J. M. Watson, Norwich, UK Sheila Crowe, Charlottesville, VA Raoul Poupon, Paris, France Stefan Zeuzem, Frankfurt, Germany

Tu1432 A Longitudinal Study of Clinical Parameters and Cytokine Profiles in IBS

Background: In western populations where there is a high prevalence of celiac disease (CD), serological and tissue markers were found to be more common in patients with irritable bowel syndrome (IBS) phenotype. While CD is believed to be uncommon in Chinese, there is a report from China suggesting that this association may also exist. Aim: To study the prevalence of celiac disease markers in patients with IBS criteria and of Chinese ethnicity from Singapore, where there has been increasing wheat consumption. Method: We explored this association in a cohort of ethnic Chinese patients with IBS by Rome III criteria, who had all undergone IgA anti-gliadin antibody (AGA) and IgA anti-endomysial antibody (EMA) serology testing and duodenal biopsies as part of their clinical workup. In addition, we recalled patients with positive serology for further test of human leukocyte antigens HLADQ2 and HLA-DQ8, which are known to be associated with celiac disease. Result: In 106 patients of Chinese ethnicity who fulfilled Rome III IBS criteria 16 (15.1%) were tested positive for AGA, and 7 (6.6%) had intra-epithelial lymphocytosis reported in duodenal biopsies. None of the patients was positive for EMA. The prevalence of intra-epithelial lymphocytosis (IEL) was numerically higher in patients with positive AGA than negative AGA serology, with 3 (18.8%) and 4 (4.4%) respectively (p=0.105). Similarly, villous atrophy was numerically more common in AGA positive than AGA negative group with 8(50%) and 30(33.3%) respectively (p=0.20). None of these patients had more than mild villous atrophy. The prevalence of Helicobacter pylori infection in AGA positive and AGA negative groups were 18.8% and 28.9% respectively (p=0.40). Nine of the 16 patients in the AGA positive group agreed to undergo HLA-DQ2/8 genotyping, and only 2 patients were positive for HLA-DQ8. These two HLA-DQ positive patients are sisters whose parents had emigrated from the northern part of China where the traditional dietary staple was wheat. Neither of them had villous atrophy, but one had IEL. The other 7 patients who were HLA-DQ2/8 genotype negative were descended from tribes in the southern part of China; one of the patients had concurrent systemic lupus erythematosus (SLE). Five of the 7 patients had villous atrophy, while two of the 7 patients had IEL. Conclusion: Our observations suggest that celiac disease could be present in some ethnic Chinese patients with IBS criteria. However there is a subset of Chinese patients with positive anti-gliadin serology who do not have the full histologic features for celiac disease and were HLA haplotype negative, suggesting that these patients could IBS associated with an immune sensitization to gluten not amounting to celiac disease.

The Clinical Implications of Childhood Traumatic Events in Irritable Bowel Syndrome.

G A A b st ra ct s correlations were noted between abdominal pain and right colon transit time (r=-0.18; p<0.05) and bloating and left colon transit time (r=0.16; p<0.05). No associations were found between CTT and other GI symptoms, age, anxiety or depression. Conclusion: Total and segmental colonic transit alterations are of importance for the abnormal bowel habit seen in men and women with IBS, but of no or minor importance for other IBS symptoms. Colonic transit is not associated with psychological symptoms.