Loftus, Edward V.

Summary Background Serological markers such as anti‐neutrophil cytoplasmic antibody ( ANCA ) and anti‐ S accharomyces cerevisiae antibody ( ASCA ) may be associated with pouchitis after ileal pouch‐anal anastomosis ( IPAA ). Aim To perform a systematic review with meta‐analysis of studies evaluating the association of ANCA and ASCA status with risk of acute and chronic pouchitis after IPAA . Methods We searched multiple databases (upto S eptember 2012) for studies reporting ANCA and/or ASCA status along with risk of acute or chronic pouchitis after IPAA in adults with ulcerative colitis ( UC ). We abstracted odds ratio ( OR ) or raw data from the individual studies to calculate summary OR estimates with 95% CI s using random‐effects model. Results Eight studies reporting 184 cases of acute pouchitis and six studies reporting 151 cases of chronic pouchitis were included. The odds of chronic pouchitis were 76% higher in ANCA ‐positive patients than ANCA ‐negative (six studies; OR : 1.76; 95% CI : 1.19–2.61; P < 0.01). ASCA‐positivity was not associated with the risk of chronic pouchitis (three studies; OR : 0.89; 95% CI : 0.49–1.59; P = 0.68). Neither ANCA (eight studies; OR : 1.54; 95% CI : 0.79–3.02; P = 0.21) nor ASCA ‐positivity (two studies; OR : 1.28; 95% CI : 0.25–6.54; P = 0.77) were associated with the risk of acute pouchitis. Conclusions The risk of chronic pouchitis after IPAA is higher in ANCA ‐positive patients, but the risk of acute pouchitis is unaffected by ANCA status. ASCA status was not associated with the risk of acute or chronic pouchitis. This information may be used to counsel UC patients regarding their risk of pouchitis after IPAA .

SummaryBackgroundCurrent approaches to the detection of colorectal neoplasia associated with inflammatory bowel disease (IBD‐CRN) are suboptimal.AimTo test the feasibility of using stool assay of exfoliated DNA markers to detect IBD‐CRN.MethodsThis investigation comprised tissue and stool studies. In the tissue study, gene sequencing and methylation assays were performed on candidate genes using tissue DNA from 25 IBD‐CRNs and from 25 IBD mucosae without CRN. Mutations on p53, APC, KRAS, BRAF or PIK3CA genes were insufficiently informative, but several aberrantly methylated genes were highly discriminant. In the stool study, we evaluated candidate methylated genes (vimentin, EYA4, BMP3, NDRG4) in a prospective blinded study on buffered stools from 19 cases with known IBD‐CRN and 35 age‐ and sex‐matched IBD controls without CRN. From stool‐extracted DNA, target genes were assayed using quantitative allele‐specific real‐time target and signal amplification method.ResultsIBD‐CRN cases included 17 with ulcerative colitis (UC) and two with Crohn's disease (CD); nine had cancer and 10 had dysplasia. Controls included 25 with UC and 10 with CD. Individually, BMP3, vimentin, EYA4 and NDRG4 markers showed high discrimination in stools with respective areas under the ROC curve of 0.91, 0.91, 0.85 and 0.84 for total IBD‐CRN and of 0.97, 0.97, 0.95 and 0.85 for cancer. At 89% specificity, the combination of BMP3 and mNDRG4 detected 9/9 (100%) of CRC and 80% of dysplasia, 4/4 (100%) of high grade and 4/6 (67%) of low grade.ConclusionThese findings demonstrate the feasibility of stool DNA testing for non‐invasive detection of colorectal neoplasia associated with inflammatory bowel disease.

The changing epidemiology of inflammatory bowel disease (IBD) across time and geography suggests that environmental factors play a major role in modifying disease expression. Disease emergence in developing nations suggests that epidemiological evolution is related to westernisation of lifestyle and industrialisation. The strongest environmental associations identified are cigarette smoking and appendectomy, although neither alone explains the variation in incidence of IBD worldwide. Urbanisation of societies, associated with changes in diet, antibiotic use, hygiene status, microbial exposures and pollution have been implicated as potential environmental risk factors for IBD. Changes in socioeconomic status might occur differently in different geographical areas and populations and, consequently, it is important to consider the heterogeneity of risk factors applicable to the individual patient. Environmental risk factors of individual, familial, community-based, country-based and regionally based origin may all contribute to the pathogenesis of IBD. The geographical variation of IBD provides clues for researchers to investigate possible environmental aetiological factors. The present review aims to provide an update of the literature exploring geographical variability in IBD and to explore the environmental risk factors that may account for this variability.

SummaryBackgroundUlcerative colitis (UC) and Crohn's disease can sometimes relapse and be refractory to standard treatment following orthotopic liver transplantation (OLT) despite post‐transplantation immunosuppressive therapy.AimTo evaluate the efficacy and safety of anti‐tumour necrosis factor (anti‐TNF) agents for the management of IBD following OLT.MethodsWe reviewed the records of patients with a diagnosis of IBD who underwent OLT at Mayo Clinic Rochester between 1985 and 2009. Patients were included if they had received anti‐TNF therapy post‐OLT. Clinical response was defined as a physician's assessment of improvement after 12 weeks of anti‐TNF usage, and mucosal healing was defined as the absence of ulcerations on follow‐up endoscopy.ResultsThe median age of the eight study patients was 42.0 years and 37.5% were female patients. All had been diagnosed with IBD prior to OLT (UC in three and Crohn's disease in five). Indication for OLT was cirrhotic stage primary sclerosing cholangitis (PSC), and three concomitantly had cholangiocarcinoma. Clinical response was demonstrated in seven of eight patients (87.5%) and mucosal healing was demonstrated in three of seven (42.9%). Four infections (oral candidiasis, Clostridium difficile colitis, bacterial pneumonia and cryptosporidiosis) in three patients were reported. One patient developed an Epstein–Barr virus‐positive post‐transplant lympho‐proliferative disorder. One death occurred due to complications from recurrent PSC.ConclusionsStarting Anti‐TNF therapy following orthotopic liver transplantation appears to be a potential option for inflammatory bowel disease management. Additional studies are needed, however, to confirm these findings and to further assess risks associated with this treatment strategy.

Objective: Although the epidemiology of microscopic colitis has been described in Europe, no such data exist from North America. We studied the incidence, prevalence and temporal trends of microscopic colitis in a geographically defined US population. Design and setting: In this population based cohort study, residents of Olmsted County, Minnesota, with a new diagnosis of microscopic colitis, and all who had colon biopsies for evaluation of diarrhoea, between 1 January 1985 and 31 December 2001 were identified. Biopsies were reviewed for confirmation (cases) and to identify missed cases (diarrhoea biopsies). Main outcome measures: Incidence rates, age and sex adjusted to the 2000 US white population. Poisson regression assessed the association of calendar period, age and sex with incidence. Results: We identified 130 incident cases for an overall rate of 8.6 cases per 100 000 person-years. There was a significant secular trend, with incidence increasing from 1.1 per 100 000 early in the study to 19.6 per 100 000 by the end (p<0.001). Rates increased with age (p<0.001). By subtype, the incidence was 3.1 per 100 000 for collagenous colitis and 5.5 per 100 000 for lymphocytic colitis. Collagenous colitis was associated with female sex (p<0.001) but lymphocytic colitis was not. Prevalence (per 100 000 persons) on 31 December 2001 was 103.0 (39.3 for collagenous colitis and 63.7 for lymphocytic colitis). Conclusions: The incidence of microscopic colitis has increased significantly over time, and by the end of the study, the incidence and prevalence were significantly higher than reported previously. Microscopic colitis is associated with older age, and collagenous colitis is associated with female sex.

Background: Few studies have correlated computed tomography (CT) enterography findings with endoscopic severity and C reactive protein (CRP) concentrations. Aim: To examine whether small bowel inflammation at CT enterography correlates with endoscopic severity and CRP in patients with Crohn’s disease (CD). Methods: CT enterography datasets from 143 CD patients undergoing ileoscopy were examined for three different CT parameters: CT bowel enhancement, as defined by the ratio of terminal ileal versus control ileal loop attenuation; vascular enlargement of the vasa recta (“the comb sign”); and mesenteric fat density. Correlations between CT scan parameters, endoscopy, and histology severity scores, and CRP were assessed using Spearman’s rank correlation and logistic regression. Results: Endoscopic score was significantly correlated with CT bowel enhancement, comb sign, and fat density (Spearman correlation coefficients 0.33–0.39; p<0.001). Correlations with histological inflammation were strongest for bowel enhancement (r = 0.34–0.38; p<0.001). CRP was elevated in patients with increased fat density versus those with increased bowel enhancement only (median 0.96 v 0.23, p = 0.002). CRP did not differ significantly between patients without evidence of active Crohn’s and those with bowel enhancement and endoscopic inflammation not involving the perienteric tissues by CT (median 0.24 v 0.36; p = 0.38). Conclusion: Quantitative measures of bowel enhancement at CT enterography correlate with endoscopic and histological severity. CRP correlates with radiological findings of perienteric inflammation (increased fat density), but not of inflammation limited to the small bowel wall, underscoring the potential role of perienteric inflammation in CRP response in CD.

AIM We evaluated the effect of coadministration of sulphasalazine, mesalamine, and balsalazide on the pharmacokinetics and pharmacodynamics of azathioprine and 6-mercaptopurine. METHODS Thirty four patients with Crohn's disease receiving azathioprine or 6-mercaptopurine were enrolled in an eight week non-randomised parallel group drug interaction study and treated with mesalamine 4 g/day, sulphasalazine 4 g/day, or balsalazide 6.75 g/day. The primary outcome measure was the occurrence of clinically important leucopenia during the study, defined separately as total leucocyte counts <3.0 x 10 9 /l and ⩽3.5×10 9 /l. Whole blood 6-thioguanine nucleotide concentrations were determined. RESULTS Three patients could not be evaluated for the primary outcome measure. In the remaining 31 patients, the frequency of total leucocyte counts <3.0 and ⩽3.5 were: 1/10 and 5/10 in the mesalamine group; 1/11 and 6/11 in the sulphasalazine group; and 0/10 and 2/10 in the balsalazide group. There were significant increases in mean whole blood 6-thioguanine nucleotide concentrations from baseline at most time points in the mesalamine and sulphasalazine groups but not in the balsalazide group. CONCLUSIONS In patients with Crohn's disease receiving azathioprine or 6-mercaptopurine, coadministration of mesalamine, sulphasalazine, and possibly balsalazide results in an increase in whole blood 6-thioguanine nucleotide concentrations and a high frequency of leucopenia.