Pretreatment HLADQA1-HLADRB1 Testing for the Prevention of Azathioprine-Induced Pancreatitis in Inflammatory Bowel Disease: A Prospective Cohort Study.

INTRODUCTION: Azathioprine-induced pancreatitis is an idiosyncratic and unpredictable response, occurring in up to 7% of azathioprine-exposed patients with inflammatory bowel disease (IBD). The haplotype HLADQA1-HLADRB1*07:01A>C is strongly associated with azathioprine-induced pancreatitis in IBD. We aimed to evaluate whether pretreatment HLADQA1-HLADRB1*07:01A>C screening will reduce the risk of azathioprine-induced pancreatitis. METHODS: Participants with IBD were screened for HLADQA1-HLADRB1*07:01A>C, and participants with a variant genotype were excluded from azathioprine treatment. Wild-type participants were started on azathioprine and followed for 3 months. The incidence of pancreatitis was compared with unscreened historical controls. RESULTS: HLADQA1-HLADRB1*07:01A>C screening resulted in an 11-fold reduction in the incidence of azathioprine-induced pancreatitis (n = 1/328 or 0.30% vs n = 13/373 or 3.4%). In propensity score-matched cohorts (age and sex), HLA DQA1-HLADRB1*07:01A>C screening was significantly associated with a reduction in the incidence of AZA-induced pancreatitis independent of weight, glucocorticoid exposure, and smoking status (adjusted odds ratio = 0.075, 95% confidence interval = 0.01-0.58, P = 0.01). Up to 45% (n = 271/599) of participants were excluded from azathioprine therapy based on the haplotype in the HLADQA1-HLADRB1*07:01A>C-screened cohort. DISCUSSION: HLADQA1-HLADRB1*07:01A>C screening reduced the risk of azathioprine-induced pancreatitis; however, using this strategy to guide the use of azathioprine therapy in IBD may eliminate a large proportion of patients from being eligible for treatment with azathioprine. In regions where there is access to other IBD therapies, and given the short-term and long-term toxicities associated with azathioprine, HLADQA1-HLADRB1*07:01A>C-screening may be a clinically relevant strategy for enhancing the safe use of azathioprine in IBD. In addition, cost-effectiveness analyses are needed to further solidify the utility of HLADQA1-HLADRB1*07:01A>C screening in IBD populations.

Safety of Combination Biologic and Antirejection Therapy Post-Liver Transplantation in Patients With Inflammatory Bowel Disease.

BACKGROUND: Patients with inflammatory bowel disease (IBD) post-liver transplant (LT) may have bowel inflammation requiring biologic therapy. We aimed to evaluate the safety of combination biologic and antirejection therapy in IBD patients after LT from a tertiary center case series and an updated literature review. METHODS: Inflammatory bowel disease patients undergoing LT between 1985 and 2018 and requiring combination biologic and antirejection therapy post-LT were identified from the London Health Sciences Transplant Registry (Ontario, Canada). Safety outcomes were extracted by medical chart review. For an updated literature review, EMBASE, Medline, and CENTRAL were searched to identify studies evaluating the safety of combination biologic and antirejection therapy in IBD patients. RESULTS: In the case series, 19 patients were identified. Most underwent LT for primary sclerosing cholangitis (PSC; 14/19, 74%) treated with anti-integrins (8/19, 42%) or tumor necrosis factor α (TNF) antagonists (6/19, 32%). Infections occurred in 11/19 (58%) patients, most commonly Clostridium difficile (4/19, 21%). Two patients required colectomy, and 1 patient required re-transplantation. In the literature review, 13 case series and 8 case reports reporting outcomes for 122 IBD patients treated with biologic and antirejection therapy post-LT were included. PSC was the indication for LT in 97/122 (80%) patients, and 91/122 (75%) patients were treated with TNF antagonists. Infections occurred in 32/122 (26%) patients, primarily Clostridium difficile (7/122, 6%). CONCLUSIONS: Inflammatory bowel disease patients receiving combination biologic and antirejection therapy post-LT appeared to be at increased risk of Clostridium difficile. Compared with the general liver transplant population in the published literature, there was no increased risk of serious infection.

Crohn's Disease Is Associated with Decreased CYP3A4 and P-Glycoprotein Protein Expression.

Cytochrome P450 (CYP) 3A4 and P-glycoprotein (P-gp) have broad substrate overlap and are involved in the metabolism and transport of nearly 50% of currently prescribed medications. In the intestine, CYP3A4 and P-gp are coexpressed in the enterocytes at the intestinal villous tip and act in a coordinated manner to limit drug and xenobiotic oral bioavailability prior to further metabolism and disposition in the liver. Crohn's disease (CD), a form of inflammatory bowel disease, introduces a transmural intestinal insult that disrupts the intestinal barrier function; it therefore has the potential to affect intestinal drug metabolism and transport. We hypothesized that individuals with CD have reduced intestinal expression of CYP3A4 and P-gp. We obtained intestinal biopsy samples from individuals with and without CD and quantified the expression of CYP3A4 and P-gp. When we carried out Western analysis for protein expression, we observed a significant reduction in ileal (45% decrease) and colonic (78% decrease) CYP3A4 protein expression in subjects with CD compared with those without. Similarly, an 85% reduction in colonic P-gp protein expression was seen in the CD patients. Our data highlight important and novel findings pertaining to CD-associated changes to the intestinal expression of CYP3A4 and P-gp that are of relevance to better predict substrate drug dosing for patients with CD.

Systematic review with meta-analysis: high prevalence and cost of continued aminosalicylate use in patients with ulcerative colitis escalated to immunosuppressive and biological therapies.

BACKGROUND: Aminosalicylates are the most frequently prescribed treatment for ulcerative colitis (UC). In the absence of empirical evidence, clinicians are uncertain whether to continue aminosalicylates in patients with UC after escalating therapy. AIMS: To quantify concomitant aminosalicylate use in UC randomised clinical trials (RCTs), identify factors associated with their use, and estimate treatment costs of concomitant aminosalicylate therapy. METHODS: MEDLINE, Embase, and CENTRAL were searched from inception to 1 March 2017 for placebo-controlled RCTs of immunosuppressants, biologics, or oral small molecules in adults with UC. The proportion of patients prescribed concomitant aminosalicylates at trial entry was pooled using a random-effects model. Meta-regression was performed to assess trial-level factors associated with aminosalicylate use. Treatment costs were estimated using 2018 formulary data from five Canadian provinces. RESULTS: Thirty-two trials were included (23 induction only, nine induction, and maintenance trials). The pooled proportion of patients co-prescribed aminosalicylates was 80.7% (95% CI 75.5%-85.1%), with considerable observed heterogeneity (I2  = 95%). In univariable meta-regression, aminosalicylate use was not associated with trial design, setting, year of publication, disease severity, disease duration, or drug class. The estimated direct annual treatment cost of concomitant aminosalicylates is ~$20 million for the Canadian UC population, assuming conservative estimates of UC prevalence, aminosalicylate use and dose, and the lowest cost formulation. CONCLUSIONS: Approximately 80% of UC patients entering clinical trials of immunosuppressants, biologics, or oral small molecules continue to use aminosalicylates. An RCT is needed to inform the benefits and harms of continuing vs stopping aminosalicylates in patients escalating therapy.

Inflammatory bowel disease patients prioritize mucosal healing, symptom control, and pain when choosing therapies: results of a prospective cross-sectional willingness-to-pay study.

BACKGROUND: Given the large armamentarium of therapies for inflammatory bowel disease (IBD), physicians cannot fully describe all treatments to patients and, therefore, make assumptions regarding treatment attributes communicated to patients. This study aimed to assess out-of-pocket willingness-to-pay that IBD patients allocate to treatment attributes. METHODS: Adult patients receiving therapy for IBD were invited to access a cross-sectional web-based discrete-choice experiment (May 22-August 31, 2015) that presented paired medication scenarios with varying efficacy, safety, and administration parameters. Preference weights and willingness-to-pay for each attribute level were assessed by a hierarchical Bayes method including a multinomial logit model. RESULTS: A total of 586 IBD patients were included, 404 (68.9%) with Crohn's disease and 182 (31.1%) with ulcerative colitis. Genders were evenly distributed; the majority of patients (70.1%) were 50 years or younger and had postsecondary education (75.4%), while the median health status was 7 (Likert scale: 1 [poor] - 10 [perfect]). Regarding relative preference-weight estimates, for the average respondent, reducing pain during administration, mucosal healing, and symptom relief were the highest-ranking attributes. Conversely, infusion reactions and risk of hospitalization or surgery were the lowest-ranking attributes. In multivariate analysis, patient sociodemographics did not affect the rank order of attributes although small differences were observed between asymptomatic and symptomatic patients in the previous year. CONCLUSION: This study has important implications related to understanding patient preferences and designing patient-centered strategies. IBD patients prioritize treatments with low administration pain. Additionally, these results concur with treatment guidelines emphasizing patients' preference for mucosal healing and symptom control.

Validation of international algorithms to identify adults with inflammatory bowel disease in health administrative data from Ontario, Canada.

OBJECTIVE: Health administrative databases can be used to track disease incidence, outcomes, and care quality. Case validation is necessary to ensure accurate disease ascertainment using these databases. In this study, we aimed to validate adult-onset inflammatory bowel disease (IBD) identification algorithms. STUDY DESIGN AND SETTING: We used two large cohorts of incident patients from Ontario, Canada to validate algorithms. We linked information extracted from charts to health administrative data and compared the accuracy of various algorithms. In addition, we validated an algorithm to distinguish patients with Crohn's from those with ulcerative colitis and assessed the adequate look-back period to distinguish incident from prevalent cases. RESULTS: Over 5,000 algorithms were tested. The most accurate algorithm to identify patients 18 to 64 years at diagnosis was five physician contacts or hospitalizations within 4 years (sensitivity, 76.8%; specificity, 96.2%; positive predictive value (PPV), 81.4%; negative predictive value (NPV), 95.0%). In patients ≥65 years at diagnosis, adding a pharmacy claim for an IBD-related medication improved accuracy. CONCLUSION: Patients with adult-onset incident IBD can be accurately identified from within health administrative data. The validated algorithms will be applied to administrative data to expand the Ontario Crohn's and Colitis Cohort to all patients with IBD in the province of Ontario.

Computer-based virtual reality colonoscopy simulation improves patient-based colonoscopy performance.

BACKGROUND: Colonoscopy simulators that enable one to perform computer-based virtual colonoscopy now exist. However, data regarding the effectiveness of this virtual training are limited. OBJECTIVE: To determine whether virtual reality simulator training translates into improved patient-based colonoscopy performance. METHODS: The present study was a prospective controlled trial involving 18 residents between postgraduate years 2 and 4 with no previous colonoscopy experience. These residents were assigned to receive 16 h of virtual reality simulator training or no training. Both groups were evaluated on their first five patient-based colonoscopies. The primary outcome was the number of proctor 'assists' required per colonoscopy. Secondary outcomes included insertion time, depth of insertion, cecal intubation rate, proctor- and nurse-rated competence, and patient-rated pain. RESULTS: The simulator group required significantly fewer proctor assists than the control group (1.94 versus 3.43; P ≤ 0.001), inserted the colonoscope further unassisted (43 cm versus 24 cm; P=0.003) and there was a trend to intubate the cecum more often (26% versus 10%; P=0.06). The simulator group received higher ratings of competence from both the proctors (2.28 versus 1.88 of 5; P=0.02) and the endoscopy nurses (2.56 versus 2.05 of 5; P=0.001). There were no significant differences in proctor-, nurse- or patient-rated pain, or attention to discomfort. CONCLULSIONS: Computer-based colonoscopy simulation in the initial stages of training improved novice trainees' patient-based colonoscopy performance.

Resource implications for a population-based colorectal cancer screening program in Canada: a study of the impact on colonoscopy capacity and costs in London, Ontario.

OBJECTIVE: Cancer Care Ontario has recommended a population-based colorectal cancer (CRC) screening program using fecal occult blood testing. Patients who test positive should undergo further investigation, preferably colonoscopy. So far, no studies have been performed to quantify the costs or demands on the health care system at the community level. The number of consultations, colonoscopies and polypectomies, and the corresponding direct medical costs generated by the CRC screening program, between 2006 and 2015 in London, Ontario, were estimated using a decision analysis model in comparison with the population health model. METHODS: A faxed survey study was conducted to examine the current CRC screening practice among family physicians in London. Data from the survey and randomized studies were applied to a decision analysis model, which simulated the steps involved in population-based biennial and annual CRC screening between 2006 and 2015. The number of consultations, colonoscopies and polypectomies, and their associated costs were calculated. RESULTS: For a cohort population of 140,000, between 50 and 74 years of age, in 2006 to 2015, it is estimated that an average of 412 consultations, 463 colonoscopies and 174 polypectomies will be performed per 100,000 screen eligible population per year in biennial screening, and double in annual screening, reflecting an average of 8.7% or 17.6% increase annually in outpatient colonoscopies, respectively, compared with 2003. A mean of $285,000 or $562,000 per year would be required to support the extra consultation and endoscopic procedures generated by the biennial or annual screening. CONCLUSION: Population-based fecal occult blood testing screening for CRC appears to be a manageable strategy if a modest increase in endoscopic resources is allocated.

Eosinophilic esophagitis in adults: distinguishing features from gastroesophageal reflux disease: a study of 41 patients.

Eosinophilic esophagitis in adults is a recently described entity occurring in young males with dysphagia, in whom esophageal biopsies show eosinophilic infiltration. This study defines the clinical and histological features of patients with eosinophilic esophagitis, distinguishing it from gastroesophageal reflux disease. Esophageal biopsies from patients with dysphagia or esophagitis were reviewed blindly, and assessed for: epithelial eosinophil counts, presence of eosinophilic microabscesses, edema, basal zone hyperplasia, lamina propria papillae elongation, eosinophils and fibrosis. Clinical and endoscopic findings were obtained. Eosinophilic esophagitis was diagnosed with epithelial eosinophils > or = 15 in > or = 2 high-power fields (hpfs) or > or = 25 in any hpf. Analysis was performed with Mann-Whitney, chi2 and ANOVA tests. Of 157 cases, 41 had eosinophilic esophagitis. Male gender (81%) and age < or = 45 (54%) were commoner in patients with eosinophilic esophagitis (P = 0.001, 0.010, respectively). Dysphagia was more common in eosinophilic esophagitis patients (63%, P < 0.001); heartburn was more common in noneosinophilic esophagitis patients (53%, P < 0.001). Endoscopic rings were more common in eosinophilic esophagitis patients (27%, P = 0.023); hiatus hernia was more common in noneosinophilic esophagitis patients (11%, P = 0.022). Eosinophils were more numerous in eosinophilic esophagitis biopsies (mean 39/hpf, P < or = 0.001). Only eosinophilic esophagitis biopsies had eosinophilic microabscesses (42%, P < or = 0.001). Edema, basal zone hyperplasia, lamina propria papillae elongation and lamina propria eosinophils were commoner in eosinophilic esophagitis (P < or = 0.001-0.002), while lamina propria fibrosis was specific for eosinophilic esophagitis (39%, P < 0.001). Eosinophilic esophagitis is a disease with a predilection for young males with dysphagia and rings on endoscopy. Biopsies in eosinophilic esophagitis have high epithelial eosinophil counts, averaging nearly 40/hpf. Increased awareness of eosinophilic esophagitis is necessary, since treatment with allergen elimination or anti-inflammatory therapy may be more effective than acid suppression.