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OBJECTIVES:The incidence and prevalence of inflammatory bowel disease (IBD) is increasing throughout Asia. Since the 1950s, there has been substantial migration from South Asia (India, Pakistan, and Bangladesh) to the United Kingdom. The aim of this study was to define the clinical phenotype of IBD in UK South Asians living in North West London, and to compare the results with a white Northern European IBD cohort.METHODS:The phenotypic details of 367 South Asian IBD patients (273 ulcerative colitis (UC) and 94 Crohn's disease (CD)), undergoing active follow-up in five North West London hospitals, were compared with those of 403 consecutively collected white Northern European IBD patients (188 UC and 215 CD).RESULTS:The phenotype of IBD differed significantly between the two populations. 63.0% of South Asian UC patients had extensive colitis compared with 42.5% of the Northern European cohort (P<0.0001). Proctitis was uncommon in South Asian UC patients (9.9 vs. 26.1% in Northern European patients, P<0.0001). In the South Asian CD cohort, disease location was predominantly colonic (46.8%). CD behavior differed significantly between the groups, with less penetrating disease compared with Northern Europeans (P=0.01) and a reduced need for surgery (P=0.003).CONCLUSIONS:The phenotype of IBD in South Asians living in North West London is significantly different from that of a white Northern European IBD cohort. Knowledge of ethnic variations in disease phenotype may help to identify key genetic, environmental, and behavioral factors contributing to the development of IBD. [ABSTRACT FROM AUTHOR]

OBJECTIVES:Distinguishing between the inflammatory bowel disease (IBD), Crohn's disease (CD), and ulcerative colitis (UC) is important for both management and prognostic reasons. Discrimination using noninvasive techniques could be an adjunct to conventional diagnostics. Differences have been shown between the intestinal microbiota of CD and UC patients and controls; the gut bacteria influence specific urinary metabolites that are quantifiable using proton high-resolution nuclear magnetic resonance (NMR) spectroscopy. This study tested the hypothesis that such metabolites differ between IBD and control cohorts, and that using multivariate pattern-recognition analysis, the cohorts could be distinguished by urine NMR spectroscopy.METHODS:NMR spectra were acquired from urine samples of 206 Caucasian subjects (86 CD patients, 60 UC patients, and 60 healthy controls). Longitudinal samples were collected from 75 individuals. NMR resonances specific for metabolites influenced by the gut microbes were studied, including hippurate, formate, and 4-cresol sulfate. Multivariate analysis of all urinary metabolites involved principal components analysis (PCA) and partial least squares discriminant analysis (PLS-DA).RESULTS:Hippurate levels were lowest in CD patients and differed significantly between the three cohorts (P<0.0001). Formate levels were higher and 4-cresol sulfate levels lower in CD patients than in UC patients or controls (P=0.0005 and P=0.0002, respectively). PCA revealed clustering of the groups; PLS-DA modeling was able to distinguish the cohorts. These results were independent of medication and diet and were reproducible in the longitudinal cohort.CONCLUSIONS:Specific urinary metabolites related to gut microbial metabolism differ between CD patients, UC patients, and controls. The emerging technique of urinary metabolic profiling with multivariate analysis was able to distinguish these cohorts.Am J Gastroenterol 2009; 104:1435–1444; doi:10.1038/ajg.2009.175; published online 28 April 2009 [ABSTRACT FROM AUTHOR]

AIMS: The aim of this study was to assess the diagnostic precision of anti Saccharomyces cerevisiae (ASCA) and perinuclear antineutrophil cytoplasmic antibodies (pANCA) in inflammatory bowel disease (IBD) and evaluate their discriminative ability between ulcerative colitis (UC) and Crohn's disease (CD). METHODS: Meta-analysis of studies reporting on ASCA and pANCA in IBD was performed. Sensitivity, specificity, and likelihood ratios (LR+, LR–) were calculated for different test combinations for CD, UC, and for IBD compared with controls. Meta-regression was used to analyze the effect of age, DNAse, colonic CD, and assay type. RESULTS: Sixty studies comprising 3,841 UC and 4,019 CD patients were included. The ASCA+ with pANCA- test offered the best sensitivity for CD (54.6%) with 92.8% specificity and an area under the ROC (receiver operating characteristic) curve (AUC) of 0.85 (LR+= 6.5, LR-= 0.5). Sensitivity and specificity of pANCA+ tests for UC were 55.3% and 88.5%, respectively (AUC of 0.82; LR+= 4.5, LR-= 0.5). Sensitivity and specificity were improved to 70.3% and 93.4% in a pediatric subgroup when combined with an ASCA- test. Meta-regression analysis showed decreased diagnostic precision of ASCA for isolated colonic CD (RDOR = 0.3). CONCLUSIONS: ASCA and pANCA testing are specific but not sensitive for CD and UC. It may be particularly useful for differentiating between CD and UC in the pediatric population. [ABSTRACT FROM AUTHOR]