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Background: The hygiene hypothesis suggests that a reduction in microbial exposure contributes to an impaired immune response later in life and increases the incidence of immune-mediated diseases such as inflammatory bowel diseases (IBD). Thumb sucking and nail biting are two early habits that modulate the oral microbiota composition and antigen load., Objective: We hypothesized a lower risk of Crohn's disease (CD) and ulcerative colitis (UC) in adults with prior thumb sucking and nail biting., Methods: 918 IBD cases and their 918 siblings without IBD were asked to fill out a survey containing 32 questions on environmental factors in childhood and early adulthood. Prevalence of thumb sucking and/or nail biting at the usually well-remembered time of (1) school enrollment and (2) coming-of-age ceremonies was the predefined combined risk factor of this study., Results: 65% of the patients were female and 57% suffered from CD. About 49% of IBD patients but only 44% of their siblings reported thumb sucking/nail biting at the time of school enrollment or coming-of-age ( p  = .007). Sensitivity analysis revealed that this difference was observed in patients with CD (50% versus 41%; RR= 1.22; 95% CI 1.09-1.37, p  = .001) but not in patients with UC (49% versus 48%; RR= 1.02; 95% CI 0.90-1.17; p  = .83)., Conclusion: Contrary to our expectation and challenging the hygiene hypothesis, we found that common oral habits are not protective against IBD. Instead, nail biting at the time of school enrollment and coming-of-age was a statistically significant risk factor for CD in our cohort. Key summary Evidence available before this study: The hygiene hypothesis suggests that a reduction in microbial exposure due to improved health activities has contributed to an immunological imbalance in the intestine and an increased incidence of allergic and autoimmune diseases. A population-based birth cohort study has demonstrated that thumb-sucking and nail biting in children lead to a reduction of the risk of atopic sensitization, asthma, and hay fever. Added value of this study: Contrary to the hypothesis, thumb sucking and nail biting were not associated with a reduced risk of IBD. Instead, thumb sucking and/or nail biting at the usually well-remembered points in time of school enrollment and of religious or secular coming-of-age ceremonies was associated with a higher risk of Crohn's disease but not of ulcerative colitis. Our data did not support the hygiene hypothesis, one pathogenic concept in the context of IBD.

Background: Ileocolonoscopy represents the diagnostic standard in the work-up of patients with inflammatory bowel diseases (IBD). Patients are often reluctant to be colonoscoped because of the invasiveness and pain sensation during colonoscopy., Aims: To compare the usefulness oftransabdominal ultrasound (US) and magnetic resonance imaging (MRI) in assessing disease extension and activity in patients with IBD restricted to the terminal ileum and large bowel., Patients and Methods: 61 patients with IBD [37 Crohn's disease (CD) and 24 ulcerative colitis (UC)] were prospectively studied. All patients underwent clinical and laboratory assessment, ileocolonoscopy, transabdominal sonography, and MRI within 5 days. Involved bowel segments were defined as those with bowel wall thickness >3 mm and increased Doppler signal on US or contrast enhancement of the bowel wall on MRI. To compare disease activity endoscopic, MRI and US findings were graded with newly developed scores., Results: The segment-by-segment analysis revealed an overall accuracy of 89% for US and 73% for MRI in identifying active IBD. The accuracy was better in patients with UC than in patients with CD for both US and MRI. The endoscopic activity index (EAI) correlated stronger with the US activity index (r = 0.884) than with the MRI activity index (r = 0.344). The correlation of US and MRI activity indices with EAI was better in patients with UC compared with patients with CD. All three imaging methods showed a significant correlation with clinical disease activity in patients with UC but not in patients with CD., Conclusion: This study provides strong evidence that US should be considered as a first-choice method for follow-up of patients with IBD of the terminal ileum and large bowel.

The Gram negative bacterium Helicobacter pylori is a human pathogen which infects the gastric mucosa and causes an inflammatory process leading to gastritis, ulceration and cancer. A systematic, proteome based approach was chosen to detect candidate antigens of H. pylori for diagnosis, therapy and vaccine development and to investigate potential associations between specific immune responses and manifestations of disease. Sera from patients with active H. pylori infection (n = 24), a control group with unrelated gastric disorders (n = 12) and from patients with gastric cancer (n = 6) were collected and analyzed for the reactivity against proteins of the strain HP 26695 separated by two-dimensional electrophoresis. Overall, 310 antigenic protein species were recognized by H. pylori positive sera representing about 17% of all spots separated. Out of the 32 antigens most frequently recognized by H. pylori positive sera, nine were newly identified and 23 were confirmed from other studies. Three newly identified antigens which belong to the 150 most abundant protein species of H. pylori, were specifically recognized by H. pylori positive sera: the predicted coding region HP0231, serine protease HtrA (HP1019) and Cag3 (HP0522). Other antigens were recognized differently by sera from gastritis and ulcer patients, which may identify them as candidate indicators for clinical manifestations. The data from these immunoproteomic analyses are added to our public database (http://www.mpiib-berlin.mpg.de/2D-PAGE). This platform enables one to compile many protein profiles and to integrate data from other studies, an approach which will greatly assist the search for more immunogenic proteins for diagnostic assays and vaccine design.