Colorectal cancer prevention in ulcerative colitis: a case-control study.
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BACKGROUND: The risk of colorectal cancer (CRC) in ulcerative colitis (UC) increases with extent and duration of disease. Identifying other risk factors would allow targeting of sub-groups at greatest risk, enabling more cost-effective surveillance. METHODS: We conducted a case-control study comparing 102 cases of CRC in UC with matched controls. Odds ratios (OR) for cancer risk were estimated by conditional logistic regression. A multivariate model assessed the contribution of individual variables. RESULTS: Regular 5-aminosalicylic acid (5-ASA) therapy reduces cancer risk by 75% (OR 0.25, 95% CI: 0.13-0.48, P < 0.00001). Adjusting for other variables, taking mesalazine regularly reduces risk by 81% (OR 0.19, 95% CI: 0.06-0.61, P=0.006) and visiting a hospital doctor more than twice a year also reduces risk (OR 0.16, 95% CI: 0.04-0.60, P=0.007). Considering variables independently, having a family history of sporadic CRC in any relative increases risk fivefold (OR 5.0, 95% CI: 1.10-22.82, P < 0.04). CONCLUSIONS: CRC risk among UC patients can be reduced by regular therapy with 5-ASA medication. Colonoscopic surveillance may be best targeted on those unable to take 5-ASAs (e.g. due to allergy) and those with a positive family history of CRC. (+info)
Limited exposure of the healthy distal colon to orally-dosed formulation is further exaggerated in active left-sided ulcerative colitis.
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BACKGROUND: Active distal ulcerative colitis is often resistant to topically acting oral formulations. We speculated that the left side of the colon is underexposed to orally-dosed topical agents in patients with active distal colitis. METHODS: Twenty-two healthy volunteers (12 males, aged 22-47 years), and 10 patients (6 males, aged 33-73 years) with active left-sided ulcerative colitis ingested a Eudragit-coated gelatine capsule containing 111In-labelled amberlite resin on four successive days. Regional colonic distribution, transit times and percentage of daily dose resident were calculated from the average of four serial gamma camera images on the 4th day. RESULTS: (mean [95% CI]). When compared to controls, patients with colitis had significantly faster total colon transit (24.3 h [9.5-39.1] vs. 51.7 h [41.1-62.3]) as well as faster proximal colon transit (18.7 h [9.1-28.3] vs. 36.7 [28.5-44.9]), and distal colon transit (3.1 h [-0.5 to 6.8] vs. 15.0 h [10.5-19.5]), respectively (all P < 0.01). Material was asymmetrically distributed in health (proximal colon 69% [63-76] vs. distal colon 31% [24-37]). This asymmetry was more extreme in colitis, with corresponding values of 91% [85-96] vs. 9% [4-15]. As a result colitics had less material in the left-sided colon (9% [4-15] vs. 31% [24-37]), P < 0. 001. Colitics had a significantly lower percentage of the daily dose resident within the left side of the colon compared to controls (13% [-2 to 28] vs. 63% [44-81]), P < 0.01. CONCLUSIONS: Delayed release oral formulation is asymmetrically distributed within the colon in health. This asymmetry is exaggerated in active left-sided ulcerative colitis and, together with faster colonic transit, results in reduced exposure of the distal colon to orally-dosed topical agents. (+info)
Mycophenolate mofetil: lack of efficacy in chronic active inflammatory bowel disease.
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BACKGROUND: Mycophenolate mofetil (MMF) is a new immunosuppressant with pharmacodynamic properties comparable to azathioprine. Recent reports found MMF to be effective in inflammatory bowel disease (IBD). METHODS: An open-label prospective and uncontrolled multicentre 6 month trial of MMF in combination with steroids was conducted in 24 chronic active IBD patients. A daily steroid demand of >/= 10 mg prednisone in the preceding 2 months and a Crohn's disease activity index (CDAI) > 150, or moderate to severe activity according to Truelove, served as criteria for chronic activity. The treatment consisted of a steroid pulse and tapering protocol in combination with MMF 2 g/day. A prednisone dose of 5 mg/day was maintained during months 4-6. The primary end-point was induction and maintenance of remission. RESULTS: Only 10 of 24 patients had achieved remission after 3 months. All but one Crohn's disease patient had relapsed by the end of the study at 6 months. Depression and migraine necessitated drug withdrawal in two patients. CONCLUSION: In conclusion, MMF 2 g/day was unable to induce and maintain remission for a period of 6 months in 23 of 24 chronic active IBD patients. Further controlled investigations are required in view of recent conflicting reports. (+info)
Ulcerative colitis in Olmsted County, Minnesota, 1940-1993: incidence, prevalence, and survival.
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BACKGROUND: There is significant geographic variation in the reported incidence of ulcerative colitis. AIMS: To update the incidence and prevalence of ulcerative colitis in Olmsted County, Minnesota, examine temporal trends, and determine overall survival. PATIENTS: All Olmsted County residents diagnosed with ulcerative colitis between 1940 and 1993 (incidence cases), and all residents with ulcerative colitis alive on 1 January 1991 (prevalence cases). METHODS: Incidence and prevalence rates were adjusted using 1990 US census figures for whites. The effects of age, sex, and calendar year on incidence rates were evaluated using Poisson regression. Survival from diagnosis was compared with that expected for US north-central whites. RESULTS: Between 1940 and 1993, 278 incidence cases were identified, for an adjusted incidence rate of 7.6 cases per 100 000 person years (95% confidence interval (CI), 6.7 to 8.5). On 1 January 1991, there were 218 residents with definite or probable ulcerative colitis, for an adjusted prevalence rate of 229 cases per 100 000 (95% CI, 198 to 260). Increased incidence rates were associated with later calendar years (p<0.002), younger age (p<0.0001), urban residence (p<0.0001), and male sex (p<0.003). Overall survival was similar to that expected (p>0.2). CONCLUSIONS: The overall incidence rate of ulcerative colitis in Olmsted County increased until the 1970s, and remained stable thereafter. Incidence rates among men and urban residents were significantly higher. The prevalence rate in Rochester in 1991 was 19% higher than that in 1980. Overall survival was similar to that of the general population. (+info)
Defective hMSH2/hMLH1 protein expression is seen infrequently in ulcerative colitis associated colorectal cancers.
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BACKGROUND: Ulcerative colitis is associated with an increased risk of colorectal cancer above that of the normal population. The relative risk correlates with the extent and duration of the disease but the genetic basis of ulcerative colitis associated cancer risk is not known. AIMS: To assess the prevalence of microsatellite instability and mismatch repair gene abnormalities in ulcerative colitis associated colorectal cancer. PATIENTS: Forty six patients with colorectal cancer, with a previous histological diagnosis of ulcerative colitis. METHODS: The frequency of microsatellite instability and/or immunohistochemical expression of hMSH2 and hMLH1 was assessed. Thirty three cases were investigated using both approaches. RESULTS: Although 6/41 (14.6%) cases showed microsatellite instability at one or more markers, only one case (2. 4%) exhibited high level instability (at least two markers affected). Of 38 cases which were assessed using antibodies against hMSH2 and hMLH1, only one case (2.6%) showed loss of expression. This case, which showed loss of hMSH2 expression, was the same case which exhibited high level microsatellite instability. The 33 cases which were investigated using both approaches showed that loss of expression of either hMSH2 or hMLH1 was not seen in any case which exhibited microsatellite instability in no more than one marker. CONCLUSIONS: This study suggests that both high level microsatellite instability and loss of expression of hMSH2/hMLH1 are infrequent events in ulcerative colitis associated colorectal cancers. Low level microsatellite instability was not associated with loss of expression of either hMSH2 or hMLH1. (+info)
Clinical and radiological characteristics of lung disease in inflammatory bowel disease.
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The pulmonary associations of inflammatory bowel disease (IBD) are poorly characterized. The clinical, physiological and high-resolution computed tomographic thorax characteristics of the lung disease in patients with IBD presenting with respiratory symptoms are described. Detailed clinical information was obtained and standard pulmonary physiological tests and thorax high-resolution computed tomography performed on 14 patients with ulcerative colitis (UC) and three with Crohn's disease (CD), 10 male, aged 38-83 yrs. Respiratory symptoms had been present for 2-50 yrs and extraintestinal manifestations were present in three (17.6%). Normal pulmonary physiology (six patients) was associated with the high resolution computed tomographic changes of bronchiectasis, mosaic perfusion and air trapping suggestive of obliterative bronchiolitis and a pattern of centrilobular nodules and branching linear opacities ("tree in bud" appearance) suggestive of either cellular bronchiolitis or bronchiolectasis with mucoid secretions. Bronchiectasis was found in 13 patients (11 UC, 2 CD), 11 had air trapping and five had a "tree in bud" appearance on computed tomography. One patient had a predominantly peripheral reticular pattern at the lung bases similar to that found in cryptogenic fibrosing alveolitis and one patient had a mixed reticular and ground-glass pattern in the midzones with a patchy distribution in the central and peripheral portions of the lungs with air trapping. Eleven patients (three with alveolitis) exhibited a clinical and/or physiological response to steroids. Pulmonary abnormalities in ulcerative colitis and Crohn's disease can present years after the onset of the bowel disease and can affect any part of the lungs. Early recognition is important as they can be strikingly steroid-responsive. (+info)
Colonic bacteria express an ulcerative colitis pANCA-related protein epitope.
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Bacteria are a suspected pathogenic factor in inflammatory bowel disease, but the identity of the relevant microbial species remains unresolved. The pANCA autoantibody is associated with most cases of ulcerative colitis (UC) and hence reflects an immune response associated with the disease process. This study addresses the hypothesis that pANCA identifies an antigen(s) expressed by bacteria resident in the human colonic mucosa. Libraries of colonic bacteria were generated using aerobic and anaerobic microbiologic culture conditions, and bacterial pools and clonal isolates were evaluated for cross-reactive antigens by immunoblot analysis using the pANCA monoclonal antibody Fab 5-3. Two major species of proteins immunoreactive to pANCA monoclonal antibodies were detected in bacteria from the anaerobic libraries. Colony isolates of the expressing bacteria were identified as Bacteroides caccae and Escherichia coli. Isolation and partial sequencing of the B. caccae antigen identified a 100-kDa protein without database homologous sequences. The E. coli protein was biochemically and genetically identified as the outer membrane porin OmpC. Enzyme-linked immunosorbent assay with human sera demonstrated elevated immunoglobulin G anti-OmpC in UC patients compared to healthy controls. These findings demonstrate that a pANCA monoclonal antibody detects a recurrent protein epitope expressed by colonic bacteria and implicates colonic bacterial proteins as a target of the disease-associated immune response. (+info)
A colorectal cell line with alterations in E-cadherin and epithelial biology may be an in vitro model of colitis.
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BACKGROUND: It has been shown previously in ulcerative colitis tissue that E-cadherin can occasionally be mutated in the extracellular domain early in neoplastic progression. E-cadherin is known to maintain differentiation and inhibits invasion in vivo. AIMS: To assess the mechanisms by which such dysfunction occurs. METHODS: Four human colorectal cancer cell lines, HCA-7 colonies 1, 3, 6, and 30, derived from a single heterogeneous colorectal cancer were studied. The HCA-7 cell line has p53 mutations and a random errors of replication "positive" phenotype, as is seen in early colitis associated cancers or hereditary nonpolyposis coli cancer (HNPCC). RESULTS: Cell lines 6 and 30 expressed E-cadherin abundantly and this correlated positively with their degree of differentiation and organisation; however, both cell lines had loss of heterozygosity of E-cadherin. Interestingly, E-cadherin production was downregulated in the poorly differentiated cell line 1, and this was associated with major chromosomal rearrangements of 16q. This cell line also had a mutation in the homophilic binding domain of exon 4, which was associated with disaggregation by low titres of a function blocking antibody, and an invasive phenotype. CONCLUSIONS: These multiple biological alterations further characterise the complex association that E-cadherin has with tumour heterogeneity and suggest that this series of cell lines may be a useful model of colitis associated or HNPCC associated tumorigenesis. (+info)