An international survey of polypectomy training and assessment

Background and study aims Colonic polypectomy is acknowledged to be a technically challenging part of colonoscopy. Training in polypectomy is recognized to be often inconsistent. This study aimed to ascertain worldwide practice in polypectomy training. Patients and methods An electronic survey was distributed to endoscopic trainees and trainers in 19 countries asking about their experiences of receiving and delivering training. Participants were also asked about whether formal polypectomy training guidance existed in their country. Results Data were obtained from 610 colonoscopists. Of these responses, 348 (57.0 %) were from trainers and 262 (43.0 %) from trainees; 6.6 % of trainers assessed competency once per year or less often. Just over half (53.1 %) of trainees had ever had their polypectomy technique formally assessed by any trainer. Approximately half the trainees surveyed (51.1 %) stated that the principles of polypectomy had only ever been taught to them intermittently. Of those trainees with the most colonoscopy experience, who had performed over 500 procedures, 48.2 % had had training on removing large polyps of over 10 mm; 46.2 % (121 respondents) of trainees surveyed held no record of the polypectomies they had performed. Only four of the 19 countries surveyed had specific guidelines on polypectomy training. Conclusions A significant number of competent colonoscopists have never been taught how to perform polypectomy. Training guidelines worldwide generally give little direction as to how trainees should acquire polypectomy skills. The learning curve for polypectomy needs to be defined to provide reliable guidance on how to train colonoscopists in this skill.

Increased expression of chemokine receptor CCR3 and its ligands in ulcerative colitis: the role of colonic epithelial cells in in vitro studies

Human colonic epithelial cells express T helper type 1 (Th1)-associated chemoattractants, yet little is known about the production of Th2-associated chemoattractants. CCL11/eotaxin-1, CCL24/eotaxin-2 and CCL26/eotaxin-3 are known to attract CCR3-expressing, Th2-polarized lymphocytes. We studied constitutive and inflammation-induced expression and production of CCR3 together with its ligands in the colon and peripheral blood of patients with inflammatory bowel disease (IBD) by flow cytometry, reverse transcription–polymerase chain reaction (RT–PCR) and enzyme-linked immunosorbent assay (ELISA). We further defined the regulated expression of these chemokines by RT–PCR and ELISA using cultured human epithelial cell lines. A higher fraction of peripheral T lymphocytes were found to be positive for CCR3 in patients with ulcerative colitis (UC) compared to Crohn’s disease (CD), while almost no CCR3(+) T cells were found in normal controls (NC). Similarly, higher and more frequent expression of CCR3 was observed in colonic biopsies from patients with UC, regardless of the disease activity, when compared to CD or NCs. Serum CCL11/eotaxin-1 was increased significantly in UC (306 ± 87 pg/ml) and less so in CD (257 ± 43 pg/ml), whereas CCL24/eotaxin-2, and CCL26/eotaxin-3 were increased only in UC. Colonic expression of the three chemokines was minimal in NCs but high in inflammatory bowel diseases (especially UC) and was independent of disease activity. Th2, and to a lesser extent Th1, cytokines were able to induce expression and production of all three eotaxins from colonic epithelial cells in culture. CCR3 and ligands over-expression would appear to be a characteristic of UC. The production of CCR3 ligands by human colonic epithelial cells suggests further that epithelium can play a role in modulating pathological T cell-mediated mucosal inflammation.

Phenotype at diagnosis predicts recurrence rates in Crohn's disease

BACKGROUND

In Crohn's disease (CD), studies associating phenotype at diagnosis and subsequent disease activity are important for patient counselling and health care planning.

AIMS

To calculate disease recurrence rates and to correlate these with phenotypic traits at diagnosis.

METHODS

A prospectively assembled uniformly diagnosed European population based inception cohort of CD patients was classified according to the Vienna classification for disease phenotype at diagnosis. Surgical and non-surgical recurrence rates throughout a 10 year follow up period were calculated. Multivariate analysis was performed to classify risk factors present at diagnosis for recurrent disease.

RESULTS

A total of 358 were classified for phenotype at diagnosis, of whom 262 (73.2%) had a first recurrence and 113 patients (31.6%) a first surgical recurrence during the first 10 years after diagnosis. Patients with upper gastrointestinal disease at diagnosis had an excess risk of recurrence (hazard ratio 1.54 (95% confidence interval (CI) 1.13-2.10)) whereas age >/=40 years at diagnosis was protective (hazard ratio 0.82 (95% CI 0.70-0.97)). Colonic disease was a protective characteristic for resective surgery (hazard ratio 0.38 (95% CI 0.21-0.69)). More frequent resective surgical recurrences were reported from Copenhagen (hazard ratio 3.23 (95% CI 1.32-7.89)).

CONCLUSIONS

A mild course of disease in terms of disease recurrence was observed in this European cohort. Phenotype at diagnosis had predictive value for disease recurrence with upper gastrointestinal disease being the most important positive predictor. A phenotypic North-South gradient in CD may be present, illustrated by higher surgery risks in some of the Northern European centres.

Chemoprevention of colorectal cancer in inflammatory bowel disease? A potential role for folate

Patients with ulcerative colitis have an increased risk for developing colon cancer compared to the general population. The risk is related to the extension of the disease and its duration. This risk is the same for Crohn's colitis patients of equal extension and duration. By chemoprevention we mean the use of specific natural or synthetic chemical agents to reverse, suppress or prevent progression to invasive cancer. The chemopreventive agents for colon cancer are either of natural origin (vitamins, minerals, food constituents) or synthetic chemicals (difluoromethyl ornithine) and pharmaceutical agents (aspirin, oltipraz). Apart from folate, no other agent has so far been used in vivo for the prevention of colon cancer in long-standing inflammatory bowel disease. The use of folate was, however, not primarily intended to prevent cancer but to enhance folate absorption in ulcerative colitis. From retrospective studies, within the framework of cancer surveillance programmes, it became evident that folate supplementation may play a positive role as a chemopreventive agent against colorectal cancer in patients with long-standing, extensive ulcerative colitis. There is also evidence suggesting that folate supplementation may contribute to regulation of rectal cell proliferation in ulcerative colitis patients. There is a real need for multicentre, randomized, prospective clinical studies in order to evaluate the promising role of folate in preventing colorectal cancer in patients with long-standing inflammatory bowel disease.

Ulcerative colitis is as common in Crete as in northern Europe: a 5-year prospective study

OBJECTIVE

To study the incidence of ulcerative colitis and to analyse the pattern of the disease in the prefecture of Heraklion, Crete.

PARTICIPANTS

The population at risk comprised 263,670 inhabitants in the prefecture of Heraklion (2641 km2). The two regional hospitals, five health centres, 109 private family doctors and 145 specialists participated in the study.

METHODS

A prospective and population-based epidemiological study of ulcerative colitis over five years from 1990 to the end of 1994.

RESULTS

Overall, 117 patients with ulcerative colitis (75 males and 42 females) were newly diagnosed during the study period. The mean annual incidence of the disease for the years 1990-1994 was 8.9 per 10(5) inhabitants (95% CI 7.2-10.4). The male to female ratio was 1.8:1. There were no significant difference between the age-specific incidences of the age groups. The majority (51.3%) of the patients were exsmokers and one-third had never smoked. A family history of first-degree relatives positive for inflammatory bowel disease was obtained in 9.6% of our patients.

CONCLUSION

Ulcerative colitis is common in Crete; its incidence is as high as in Northern Europe.

A prospective epidemiologic study of Crohn's disease in Heraklion, Crete. Incidence over a 5-year period

BACKGROUND

There has been an impression from published work that Crohn's disease is less common in southern than in northern Europe. A low incidence of Crohn's disease has been observed in Greece, but conclusive data are still lacking.

METHOD

A 5-year prospective and population-based epidemiologic study of Crohn's disease was carried out in a well-defined area of Crete.

RESULTS

The mean annual incidence of the disease for the years 1990-94 was 3.0 per 10(5) inhabitants. During the study period the incidence increased from 1.9/10(5) in 1990 to 3.8/10(5) in 1994. The male to female ratio was 2.4:1. The age group 25-34 years had the highest age-adjusted incidence (6.3/10(5)). The incidence of Crohn's disease was also found to be higher in smokers, in urban areas, and in people with high educational level.

CONCLUSION

Crohn's disease is common in Heraklion, Crete. The findings of the study are discussed in relation to those of other European countries.

Distribution of four polymorphisms in the tumour necrosis factor (TNF) genes in patients with inflammatory bowel disease (IBD)

In 153 patients with IBD, 64 with Crohn's disease (CD), and 89 with ulcerative colitis (UC), as well as in 54 healthy controls (HC), the frequencies of four known di-allelic polymorphisms in the genes for TNF-alpha and lymphotoxin alpha (LTalpha) were investigated. In the Dutch population, the alleles of these four polymorphisms are present in only five combinations, called TNF haplotypes: TNF-C, -E, -H, -I, -P. Furthermore, the relation with the presence of perinuclear anti-neutrophil cytoplasmic autoantibodies (P-ANCA) was studied. A small, but statistically significant, association between the polymorphism at position -308 in the promoter region of the TNF-alpha gene and UC was found. The frequency of the uncommon TNF-alpha -308 allele 2 was found to be decreased in patients with UC compared with HC (allele frequency of allele 2 in UC patients 0-15 versus 0.25 in HC, P=0.044). No significant differences in distribution of the TNF haplotypes were found between IBD patients and HC, although there was a tendency towards a higher frequency of the TNF-C haplotype in UC patients compared with controls (haplotype frequency 22% versus 13%; P=0.19). No statistically significant differences in distribution of the TNF haplotypes were observed between P-ANCA-positive and P-ANCA-negative UC patients. The strength of the associations indicates that TNF genes are not markers for the predisposition to suffer from IBD. They may, however, be markers of subsets of patients with UC and CD.

Environmental risk factors in inflammatory bowel disease

Besides a genetic predisposition, a causal role of various environmental factors have been taken into consideration in the etiology of inflammatory bowel disease (IBD). The most consistent association of environmental factors so far identified is the association between non smoking and ulcerative colitis (UC) as well a between smoking and Crohn's disease (CD). Other factors such as oral contraceptives, refined sugar, perinatal events, childhood infections, microbial agents, and domestic hygiene have been found to be associated with ulcerative colitis and Crohn's disease but further evaluation is required to confirm the consistency and to define the strength of the association. Recent data also suggest that measles virus may persist in intestinal tissue and early exposure to the virus may be a risk factor for development of CD. The further investigation of environmental factors on IBD and the explanation of their role is expected to open new avenues for basic scientific research and may lead to the development of a more rational approach to the prevention and treatment of IBD. The available data suggest that UC and CD are heterogeneous disorders of multifactorial etiology in which hereditary and environmental factors interact to produce the disease.

Evidence of genetic heterogeneity in IBD: 1. The interleukin-1 receptor antagonist in the predisposition to suffer from ulcerative colitis

OBJECTIVE

To investigate a polymorphism within intron 2 of the interleukin-1 receptor antagonist (IL-1ra) gene in a Dutch white population of patients with ulcerative colitis and Crohn's disease.

DESIGN

Genotype and allele frequencies of the polymorphic region in the IL-1ra gene were determined in 111 unrelated patients with ulcerative colitis, 92 patients with Crohn's disease, and 86 healthy controls.

METHODS

The polymorphic region on the IL-1ra gene was amplified by the polymerase chain reaction (PCR). The resultant products were analyzed by electrophoresis on 2% agarose gels and stained with ethidium bromide. Amplification of the second exon of HLA-DRB1, HLA-DQA1, and HLA-DQB1 genes was performed by PCR, and Dot-blot analysis with biotin-labelled sequence-specific oligonucleotide probes was used for HLA typing. The standard perinuclear antineutrophil cytoplasmic antibodies (pANCA) indirect immunofluorescence assay was performed according to the protocol described by the First International Workshop on ANCA.

RESULTS

The frequency of allele 2 of the IL-1ra gene in ulcerative colitis (27.0%) and Crohn's disease patients (25.5%) did not differ significantly from healthy controls (23.8%). However, the estimate of the relative risk for carriers of allele 2 for ulcerative colitis [odds ratio (OR): 1.35, 95%-confidence interval (CI) from 0.73 to 2.49] was in agreement with a previous British study. The exact test for homogeneity of odds ratios provided no evidence for heterogeneity between both populations (P = 0.35) and therefore confirmed the genetic associated between ulcerative colitis and the IL-1ra allele 2 in a different population. Our data confirm that, in ulcerative colitis, the presence of this allele is a genetic marker for severity of the disease. A significant association was demonstrated between the carriership of allele 2 of the IL-1ra gene and the trend over the three localizations in ulcerative colitis (P = 0.023). The same approach for Crohn's disease when compared with healthy controls did not provide evidence for a similar association. The meta-analysis, based on the British data and our data, yielded: OR = 1.06, 95%-CI from 0.71 to 1.59, and P = 0.767. No association between IL-1ra gene polymorphism, and pANCA and the HLA-DR2 allele was found in ulcerative colitis.

Allelic polymorphism in IL-1 beta and IL-1 receptor antagonist (IL-1Ra) genes in inflammatory bowel disease

Recent reports have shown that allele 2 of the IL-1 receptor antagonist (IL-1Ra) gene is over-represented in ulcerative colitis (UC). Healthy individuals carrying allele 2 of this gene have increased production of IL-1Ra protein. Since the final outcome of the biological effects of IL-1 beta may depend on the relative proportion of these two cytokines, we have studied if a TaqI polymorphism in the IL-1 beta gene, which is relevant to IL-1 beta protein production, may be involved in the genetic susceptibility to UC and Crohn's disease (CD), in association with the established IL-1Ra gene polymorphism. Polymorphisms in the closely linked genes for IL-1 beta and IL-1Ra were typed in 100 unrelated Dutch patients with UC, 79 with CD, and 71 healthy controls. The polymorphic regions in exon 5 of the IL-1 beta gene and in intron 2 of the IL-1Ra gene, were studied by polymerase chain reaction (PCR)-based methods. The IL-1 beta allele frequencies in UC and CD patients did not differ from those in healthy controls. In order to study if the IL-1 beta gene polymorphism might participate synergistically with the IL-1Ra gene polymorphism in susceptibility to UC and CD, individuals were distributed into carriers and non-carriers of allele 2 of the genes encoding IL-1 beta and IL-1Ra, in each of the patient groups and controls. Results indicated a significant association of this pair of genes, estimated by the odds ratio (OR) after performing Fisher's exact test, in the UC group (P = 0.023, OR = 2.81), as well as in the CD group (P = 0.01, OR = 3.79). Thus, non-carriers of IL-1 beta allele 2 were more often present in the subgroup of patients carrying the IL-1Ra allele 2. By contrast, no association of these alleles was detected in the group of healthy controls (P = 1.00, OR = 0.92). These results suggest that the IL-1 beta/IL-1Ra allelic cluster may participate in defining the biological basis of predisposition to chronic inflammatory bowel diseases.