A population- and family-based study of Canadian families reveals association of HLA DRB1*0103 with colonic involvement in inflammatory bowel disease

The aim of this study was to identify major histocompatibility complex alleles associated with the development and clinical features of inflammatory bowel disease (IBD). Genotyping at the human leukocyte antigen (HLA) DRB1 and DQB1 loci was performed on individuals from 118 Caucasian IBD sibling pair families and on 216 healthy controls. Both population- and family-based association tests were used to analyze data obtained on the entire study population and on clinical subgroups stratified by diagnosis, ethnicity, and disease distribution. HLA DRB1*0103 was significantly associated with IBD (OR = 6.0, p = 0.0001) in a case-control analysis of non-Jewish IBD-affected individuals. This association was apparent among both Crohn's disease (OR = 5.23, p = 0.0007) and ulcerative colitis (OR = 7.9, p = 0.0001) patients and was confirmed in the non-Jewish IBD population by results of family-based association analysis using the transmission disequilibrium test. HLA DQB1*0501 was also associated with IBD (OR = 1.64, p = 0.02) in the non-Jewish population. but statistically significant association of this allele with disease was not detected for Crohn's disease and ulcerative colitis separately. No significant associations were identified among the Jewish patients. In the non-Jewish IBD families, IBD was as strongly associated with the DRB1*0103 DQB1*0501 haplotype as with the DRB1*0103 allele alone. The carrier frequency of the DRB1*0103 allele was found to be 10-fold higher in Crohn's disease patients with pure colonic involvement than in healthy controls (38.5% vs. 3.2%; p = 0.0002). These data demonstrate the association of the HLA DRB1*0103 allele with both Crohn's disease and ulcerative colitis and with large intestine-restricted disease in non-Jewish IBD patients and therefore identify HLA DRB1*0103 as a potentially important contributor to disease susceptibility and to expression of colonic involvement in IBD.

Revising the troublesome stoma: combined abdominal wall recontouring and revision of stomas

PURPOSE

Despite preoperative siting and maturation of stomas, some patients may have poor stoma function because of redundant pannus, scars, creases, and parastomal or incisional hernias. In these patients, a combined abdominoplasty and stoma revision may be helpful. The object of this manuscript is to report our preliminary results.

METHODS

Eight patients (mean age, 48 years; female/male ratio, 7/1) undergoing this procedure are reported. Five patients had inflammatory bowel disease, two had malignancies, and one had multiple sclerosis with bladder and bowel involvement. Patients were contacted at two months to two years follow-up to assess functional outcome and satisfaction with the procedure.

RESULTS

Indications for surgery were difficulty maintaining an appliance (n = 7), frequent stool leakage (n = 6), and skin irritation (n = 4). Multiple surgeries (n = 4), skin creases (n = 3), scarring (n = 2), large weight loss (n = 4), and hernias (n = 5) were contributing factors. At surgery five patients had hernias repaired (3 parastomal, 2 incisional), three had stomas resited, and three underwent resections for Crohn's disease. One patient developed a seroma postoperatively. At follow-up six patients were able to maintain an appliance for at least four days, whereas one changed the appliance every three days because of personal preference. None experience stool leakage. All reported a dramatic improvement in body image.

CONCLUSION

Combined stoma revision and abdominoplasty can be performed safely and leads to improved functional results and outcome.

Surgery for inflammatory bowel diseases

Surgery is required in many patients with inflammatory bowel disease at some point in their disease. In patients with ulcerative colitis, surgery is potentially curative whereas recurrence of Crohn's disease following surgery is a common occurrence. As a result, the indications and surgical management of the two diseases may be quite different. Surgery is usually reserved for the management of complications or failure of medical treatment in Crohn's disease. Resection of the diseased segment is the usual procedure performed. While surgery usually results in an improvement in quality of life, recurrence of disease occurs frequently with reported rates of 5-90% at 1 year, depending on the criteria used. To date, there have been no surgical maneuvers which have been shown to decrease the risk of recurrence. Over the past few decades, several advances have been made in the surgical management of Crohn's disease: use of strictureplasty for extensive disease; use of laparoscopic techniques to perform surgery and the performance of the ileal pouch procedure in very selected patients. Significant advances in the surgical management of ulcerative colitis have been made in the past 50 years. Although there are several options available to patients, the preferred option now is the ileal pouch procedure. With technical modifications and with experience, this procedure can now be performed with a low complication rate, with good functional results and quality of life and excellent long-term outcome.

Factors associated with the high cost of liver transplantation in adults

OBJECTIVES

To determine the overall direct cost of liver transplantation in Canadian adults and to identify the factors that are associated with high cost.

METHODS

The direct cost of liver transplantation from the perspective of third-party payers was determined in a retrospective analysis of data from hospital charts and databases. A consecutive series of 119 adults who underwent liver transplantation between 1991 and 1992 was followed from the date of listing for transplantation to the second anniversary of the transplant. Patient-specific services during the pre-transplantation, transplantation and post-transplantation phases were compiled and costed. The primary consideration was the impact of complications on the cost of transplantation. Secondary considerations were the impact of age, sex of the patient, diagnosis and severity of liver disease on the total cost.

RESULTS

The overall mean measured cost of liver transplantation was Can$89,066 (range from Can$30,505-Can$690,431). The multivariate logistic regression model for overall costs revealed that severe liver disease (OR = 11.97), cytomegalovirus infection (OR = 6.12), additional operative procedure (OR = 4.22) and biliary complications (OR = 5.00) were associated with an increased likelihood of high cost. The addition of services that were not measured in the present analysis increased the total overall cost to a mean of $121,732 (1998 Canadian dollars, follow-up costs discounted and inflation adjusted).

INTERPRETATION

The factors that were associated with high cost of liver transplantation in Canadian adults were advanced liver disease, postoperative cytomegalovirus infection, the requirement for additional operative procedures and biliary complications.

Pregnancy, delivery, and pouch function after ileal pouch-anal anastomosis for ulcerative colitis

PURPOSE

This study was designed to evaluate the pregnancies, method of delivery, and functional results of females with chronic ulcerative colitis who have an ileal pouch-anal anastomosis.

METHODS

A mailed questionnaire was sent to all females with an ileal pouch-anal anastomosis for chronic ulcerative colitis. Information on the pregnancy, method of delivery, and outcome was collected. Those females who had a successful pregnancy and delivery were contacted by telephone to clarify results and determine pouch functional results. Other clinical information was obtained from the Mount Sinai Hospital Inflammatory Bowel Disease database.

RESULTS

Thirty-eight subjects had 67 pregnancies. Of these, 29 subjects had 49 deliveries. There were 25 vaginal deliveries and 24 cesarean sections. There were two pouch-related complications during the pregnancies and four pouch-related complications postpartum. All were treated nonoperatively. Stool frequency and day and night incontinence were increased during pregnancy in most subjects, but after delivery, prepregnancy function was restored in 24 (83 percent) of them. Five subjects (17 percent) had some degree of permanent deterioration in pouch function. Of these, three had vaginal deliveries, and two had cesarean sections. Multiple births and birth weight were not found to adversely affect subsequent pouch function.

CONCLUSION

Pregnancy is safe in females with ileal pouch-anal anastomosis. Functional results are altered almost exclusively during the third trimester, but pouch function promptly returns to prepregnancy status in most females. A small proportion of females have long-term disturbances in function, but these are not related to the method of delivery. Thus, the method of delivery should be dictated by obstetric considerations.

Reconstructive surgery for failed ileal pouch-anal anastomosis: a viable surgical option with acceptable results

PURPOSE

Salvage procedures for failed ileal pouch-anal anastomoses frequently require total reconstruction with a combined abdominal and perineal approach. The aim of this study was to determine the indications for surgery and the outcomes in this group of patients.

METHODS

All patients who underwent combined abdominal and perineal ileal pouch-anal anastomosis reconstruction at the Mount Sinai Hospital between 1982 and 2000 were reviewed. Data were collected prospectively in the inflammatory bowel disease database.

RESULTS

Sixty-three reconstructive procedures were performed in 57 patients, with a mean age of 33.9 (+/-10.4) years at the time of reconstruction. There were 14 males. The mean follow-up was 69.1 months. The initial indication for ileal pouch-anal anastomosis was ulcerative colitis in 98 percent. The primary indication for reconstruction was pouch-vaginal fistula in 21 patients, long outlet in 14, pelvic sepsis in 14, ileoanal anastomotic stricture in 5, pouch-perineal fistula in 2, and chronic pouchitis in 1. The mean operative time was four hours (+/-1.1), the average blood loss was 500 mL (+/-400), and the average length of stay was 10.3 days (+/-4.6). All patients had a diverting ileostomy. Forty-two (73.6 percent) of the patients have a functioning pouch. Seven (12.3 percent) patients have had their pouch excised. The ileostomy has not yet been closed in 8 (14 percent) patients; 3 of these patients are awaiting closure, whereas the remaining 5 have a permanently defunctioning ileostomy. Eighty-nine percent have ten or fewer bowel movements per day. No patients are incontinent of stool during the day, whereas two patients are incontinent at night. Seventeen percent complain of frequent urgency. Despite this, more than 80 percent rate their physical and psychological health as good to excellent.

CONCLUSION

Reconstructive pouch surgery has a high success rate in experienced hands. The functional results in those whose pouch is in use are good.

Risk of small bowel obstruction after the ileal pouch-anal anastomosis

OBJECTIVE

To determine the incidence of small bowel obstruction (SBO), to identify risk factors for its development, and to determine the most common sites of adhesions causing SBO in patients undergoing ileal pouch-anal anastomosis (IPAA).

METHODS

All patients undergoing IPAA at Mount Sinai Hospital were included. Data were obtained from the institution's database, patient charts, and a mailed questionnaire. SBO was based on clinical, radiologic, and surgical findings. Early SBO was defined as a hospital stay greater than 10 or 14 days because of delayed bowel function, or need for reoperation or readmission for SBO within 30 days. All patients readmitted after 30 days with a discharge diagnosis of SBO were considered to have late SBO.

RESULTS

Between 1981 and 1999, 1,178 patients underwent IPAA (664 men, 514 women; mean age 40.7 years). A total of 351 episodes of SBO were documented in 272 (23%) patients during a mean follow-up of 8.7 years (mean 1.29 episodes/patient). Fifty-four patients had more than one SBO. One hundred fifty-four (44%) of the SBOs occurred in the first 30 days; 197 (56%) were late SBOs. The cumulative risk of SBO was 8.7% at 30 days, 18.1% at 1 year, 26.7% at 5 years, and 31.4% at 10 years. The need for surgery for SBO was 0.8% at 30 days, 2.7% at 1 year, 6.7% at 5 years, and 7.5% at 10 years. In patients requiring laparotomy, the obstruction was most commonly due to pelvic adhesions (32%), followed by adhesions at the ileostomy closure site (21%). A multivariate analysis showed that when only late SBOs were considered, performance of a diverting ileostomy and pouch reconstruction both led to a significantly higher risk of SBO.

CONCLUSIONS

The risk of SBO after IPAA is high, although most do not require surgical intervention. Thus, strategies that reduce the risk of adhesions are warranted in this group of patients to improve patient outcome and decrease healthcare costs.

Dietary fibre for the prevention of colorectal adenomas and carcinomas

BACKGROUND

Colorectal cancer (CRC) is a major cause of morbidity and mortality in industrialized countries. Experimental evidence has supported the hypothesis that dietary fibre may be protective for the development of CRC, although epidemiologic data have been inconclusive.

OBJECTIVES

We have conducted a systematic review and meta-analysis to assess the effect of dietary fibre on the incidence or recurrence of colorectal adenomas, the incidence of CRC, and the development of adverse events.

SEARCH STRATEGY

We identified randomized controlled trials from Medline, Embase, and the Cochrane Controlled Trials Register up to Oct 2001

SELECTION CRITERIA

Randomized or quasi-randomized controlled trials were assessed. The population included all subjects that had adenomatous polyps but no previous history of colorectal cancer (CRC), a documented "clean colon" at baseline and repeated visualization of the colon/rectum after at least two years of follow-up. Dietary fibre was the intervention. The primary outcomes were the number of subjects with: a) at least one adenoma, b) more than one adenoma, c) at least one adenoma greater than or equal to 1 cm or d) a new diagnosis of CRC. The secondary outcome was the number of adverse events.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data, assessed trial quality and resolved discrepancies by consensus. The outcomes were reported as relative risks (RR) and risk difference (RD) with 95% confidence intervals (CI). If statistical significance was reached, the number need to treat (NNTT) or harm (NNTH) was reported. The study data were combined with the fixed effects model if it was clinically, methodologically, and statistically reasonable.

MAIN RESULTS

Five studies with 4349 subjects met the inclusion criteria. The interventions were wheat bran fibre, ispaghula husk, or a comprehensive dietary intervention with high fibre whole food sources alone or in combination. When the data were combined there was no difference between the intervention and control groups for the number of subjects with at least one adenoma [RR 1.04 (95% CI 0.95,1.13); RD 0.01 (95% CI 0.02,0.04)]. As well, the combined results for the number of subjects with more than one adenoma [RR 1.02 (95% CI 0.89,1.17), RD 0.00 (-0.02,0.03)] or at least one adenoma 1 cm or greater [RR 0.94 (95% CI 0.77,1.15), RD -0.01 (-0.02,0.01)] were not statistically significant. Other primary and secondary outcomes and subanalyses by type of fibre intervention were not statistically or clinically significant.

REVIEWER'S CONCLUSIONS

There is currently no evidence from RCTs to suggest that increased dietary fibre intake will reduce the incidence or recurrence of adenomatous polyps within a two to four year period.

Diagnostic misclassification reduces the ability to detect linkage in inflammatory bowel disease genetic studies

BACKGROUND

Linkage data have now identified several inflammatory bowel disease (IBD) susceptibility loci but these data have not been consistently replicated in independent studies. One potential explanation for this is the possibility that patients enrolled in such studies may have been erroneously classified with respect to their diagnosis.

AIMS

To determine the rate and type of misclassification in a large population of individuals referred for participation in an IBD genetics study and to examine the effect of diagnostic misclassification on the power to detect linkage.

METHODS

The medical records of 1096 patients entered into an IBD genetics programme were reviewed using standardised diagnostic criteria. The original patient reported diagnoses were changed, if necessary, based on review, and the reasons for the change in diagnosis were recorded. To evaluate the effect of misclassification on linkage results, simulations were created with Gensim and analysed using Genehunter to evaluate a model for IBD inheritance.

RESULTS

Sixty eight of 1096 (6.2%) individuals had a change in diagnosis from that originally reported. The majority of changes were patients with either Crohn's disease or ulcerative colitis who were determined not to have IBD at all. The principal reasons for changes to the original diagnosis were discordance between the patients' subjective reports of diagnosis and actual clinical history, endoscopic, or pathological results; a change in disease pattern over time; and insufficient information available to confirm the original diagnosis. A 10% misclassification rate resulted in 28.4% and 40.2% loss of power to detect a true linkage when using a statistical model for a presumed IBD locus with lambda(s) values of 1.8 and 1.3, respectively.

CONCLUSIONS

Diagnostic misclassification occurs in patients enrolled in IBD genetic studies and frequently involves assigning the diagnosis of IBD to non-affected individuals. Even low rates of diagnostic misclassification can lead to significant loss of power to detect a true linkage, particularly for loci with modest effects as are likely to be found in IBD.

Screening strategies for colorectal cancer: a systematic review of the evidence

BACKGROUND

Colorectal cancer is the third most common cancer in Canada. It is well recognized that there are improved survival rates if the disease is treated in its early stages, and indeed this may be a preventable disease. This paper systematically reviews the effectiveness of specific screening techniques for colorectal cancer in asymptomatic individuals at normal or above average risk.

METHODS

MEDLINE was searched for articles published between January 1966 and January 2001 by using the MESH terms 'screening' and 'colorectal neoplasia'. The reference sections of review articles published before January 2001 were checked, and content experts were surveyed. The evidence was evaluated using the standardized methodology of the Canadian Task Force on Preventive Health Care.

RESULTS AND DISCUSSION

For individuals at normal risk, there is evidence to support the use of annual or biennial fecal occult blood testing and flexible sigmoidoscopy for asymptomatic individuals over age 50 years. The evidence regarding whether only one or both of fecal occult blood testing and sigmoidoscopy should be performed is unclear, as is the evidence regarding the use of colonoscopy as an initial screen. For individuals at above average risk, the evidence supports either genetic testing or flexible sigmoidoscopy of individuals at risk in familial adenomatous polyposis kindreds, and screening with colonoscopy of patients in kindreds with hereditary nonpolyposis colon cancer. The evidence regarding colonoscopy for individuals who have a family history of colorectal polyps or cancer but do not fit the criteria for hereditary nonpolyposis colon cancer is unclear. Development of better risk stratification for screening is a high research priority, and further research, including randomized, controlled trials, into the effectiveness and feasibility of other screening modalities is necessary.

Genetic variation in the 5q31 cytokine gene cluster confers susceptibility to Crohn disease

Linkage disequilibrium (LD) mapping provides a powerful method for fine-structure localization of rare disease genes, but has not yet been widely applied to common disease. We sought to design a systematic approach for LD mapping and apply it to the localization of a gene (IBD5) conferring susceptibility to Crohn disease. The key issues are: (i) to detect a significant LD signal (ii) to rigorously bound the critical region and (iii) to identify the causal genetic variant within this region. We previously mapped the IBD5 locus to a large region spanning 18 cM of chromosome 5q31 (P<10(-4)). Using dense genetic maps of microsatellite markers and single-nucleotide polymorphisms (SNPs) across the entire region, we found strong evidence of LD. We bound the region to a common haplotype spanning 250 kb that shows strong association with the disease (P< 2 x 10(-7)) and contains the cytokine gene cluster. This finding provides overwhelming evidence that a specific common haplotype of the cytokine region in 5q31 confers susceptibility to Crohn disease. However, genetic evidence alone is not sufficient to identify the causal mutation within this region, as strong LD across the region results in multiple SNPs having equivalent genetic evidence-each consistent with the expected properties of the IBD5 locus. These results have important implications for Crohn disease in particular and LD mapping in general.

Identification of a critical lysine residue in apolipoprotein B-100 that mediates noncovalent interaction with apolipoprotein(a)

We have previously shown that lipoprotein(a) (Lp(a)) assembly involves an initial noncovalent interaction between sequences within apolipoprotein(a) (apo(a)) kringle IV types 5-8 and the amino terminus of apolipoprotein B-100 (sequences between amino acids 680 and 781 in apoB-100), followed by formation of a disulfide bond. In the present study, citraconylation of lysine residues in apoB-100 abolished the ability of the modified low density lipoprotein to associate with apo(a), thereby demonstrating a direct role for lysine residues in apoB in the first step of Lp(a) assembly. To identify specific lysine residues in the amino terminus of apoB that are required for the noncovalent interaction, we initially used an affinity chromatography method in which recombinant forms of apo(a) (r-apo(a)) were immobilized on Sepharose beads. Assessment of the ability of carboxyl-terminal truncations of apoB-18 to bind to r-apo(a)-Sepharose revealed that a 25-amino acid sequence in apoB (amino acids 680-704) bound specifically to apo(a) in a lysine-dependent manner; citraconylation of the lysine residues in the apoB derivative encoding this sequence abolished the binding interaction. Using fluorescence spectrometry, we found that a synthetic peptide corresponding to this sequence bound directly to apo(a); the peptide also reduced covalent Lp(a) formation. Lysine residues present in this sequence (Lys(680) and Lys(690)) were mutated to alanine in the context of apoB-18. We found that the apoB-18 species containing the Lys(680) mutation was incapable of binding to r-apo(a)-Sepharose columns, whereas the apoB-18 species containing the Lys(690) mutation exhibited slightly reduced binding to these columns. Taken together, our data indicate that Lys(680) is critical for the noncovalent interaction of apo(a) and apoB-100 that precedes covalent Lp(a) formation.

Extended follow-up of patients treated with cytotoxic chemotherapy for intra-abdominal desmoid tumors

BACKGROUND

Cytotoxic chemotherapy can achieve a good initial response in inoperable desmoid tumors that have caused progressive obstruction of the gastrointestinal and urinary tracts and have caused unrelenting pain.

METHODS

We have reviewed 8 patients (3 male) with desmoid tumors and familial adenomatous polyposis who underwent cytotoxic chemotherapy for inoperable gastrointestinal obstruction and/or uncontrolled pain. They were treated with doxorubicin and dacarbazine followed by carboplatin and dacarbazine.

RESULTS

Follow-up after cytotoxic chemotherapy in the 7 patients for whom it was available was a mean of 42 (range 24-54) months. Two patients achieved complete remission after therapy. Four patients achieved a partial remission after completing all or some of the chemotherapy regimen; of these, three remained in stable remission, whereas the other was lost to follow-up. There were two recurrences that required further therapy; one of these patients was treated with further chemotherapy, which induced a second remission, and the other was treated with pelvic exenteration and has subsequently died.

CONCLUSIONS

Most patients had a substantial response to cytotoxic chemotherapy; however, two patients required additional therapy 24 and 30 months after cytotoxic chemotherapy, respectively. Cytotoxic chemotherapy is effective in producing short-term and long-term remission in these difficult patients.

Risk of dysplasia in long-term ileal pouches and pouches with chronic pouchitis

BACKGROUND & AIMS

Recent reports have suggested the mucosa of an ileal reservoir could be at risk of neoplasia. Risk factors may include the age of the pouch, chronic pouchitis, and previous colonic neoplasia. This study examined a group of such patients to determine the risk of dysplasia.

METHODS

From a cohort of 1221 patients with ileal pouches, 171 patients with possible risk factors were selected. Successful contact was made with 138 patients who were invited for endoscopy and multiple biopsies. Biopsy specimens were stained with H&E and p53, scored for inflammatory changes including villous atrophy, and analyzed by flow cytometry.

RESULTS

One hundred six patients took part and fell into 1 or more of the following clinical categories: chronic pouchitis (n = 34), pelvic pouch for > or =12 years (n = 42); Kock pouch for > or =14 years (n = 29), and neoplasia in colectomy specimen (n = 11). Thirty-three patients had severe villous atrophy. One patient of 106 (95% confidence interval, 0.9% +/- 1.6%) with a long-standing pouch had low-grade dysplasia that was multifocal. DNA analysis by flow cytometry showed aneuploidy in this patient and 2 others.

CONCLUSIONS

These data suggest that the development of dysplasia in ileal pouches performed for ulcerative colitis is probably a rare event within 15-20 years of pouch surgery.