Gut Microbiome Composition Is Associated With Future Onset of Crohn's Disease in Healthy First-Degree Relatives.

BACKGROUND & AIMS: The cause of Crohn's disease (CD) is unknown, but the current hypothesis is that microbial or environmental factors induce gut inflammation in genetically susceptible individuals, leading to chronic intestinal inflammation. Case-control studies of patients with CD have cataloged alterations in the gut microbiome composition; however, these studies fail to distinguish whether the altered gut microbiome composition is associated with initiation of CD or is the result of inflammation or drug treatment. METHODS: In this prospective cohort study, 3483 healthy first-degree relatives (FDRs) of patients with CD were recruited to identify the gut microbiome composition that precedes the onset of CD and to what extent this composition predicts the risk of developing CD. We applied a machine learning approach to the analysis of the gut microbiome composition (based on 16S ribosomal RNA sequencing) to define a microbial signature that associates with future development of CD. The performance of the model was assessed in an independent validation cohort. RESULTS: In the validation cohort, the microbiome risk score (MRS) model yielded a hazard ratio of 2.24 (95% confidence interval, 1.03-4.84; P = .04), using the median of the MRS from the discovery cohort as the threshold. The MRS demonstrated a temporal validity by capturing individuals that developed CD up to 5 years before disease onset (area under the curve > 0.65). The 5 most important taxa contributing to the MRS included Ruminococcus torques, Blautia, Colidextribacter, an uncultured genus-level group from Oscillospiraceae, and Roseburia. CONCLUSION: This study is the first to demonstrate that gut microbiome composition is associated with future onset of CD and suggests that gut microbiome is a contributor in the pathogenesis of CD.

Environmental Factors Associated with Risk of Crohn's Disease Development in the Crohn's and Colitis Canada - Genetic, Environmental, Microbial Project.

BACKGROUND & AIMS: To date, it is unclear how environmental factors influence Crohn's disease (CD) risk and how they interact with biological processes. This study investigates the association between environmental exposures and CD risk and evaluates their association with pre-disease biomarkers. METHODS: We studied 4289 healthy first-degree relatives (FDRs) of patients with CD from the Crohn's and Colitis Canada - Genetic, Environmental, Microbial (CCC-GEM) project. Regression models identified environmental factors associated with future CD onset and their association with pre-disease biological factors, including altered intestinal permeability measured by urinary fractional excretion of lactulose to mannitol ratio (LMR); gut inflammation via fecal calprotectin (FCP) levels; and fecal microbiome composition through 16S rRNA sequencing. RESULTS: Over a 5.62-year median follow-up, 86 FDRs developed CD. Living with a dog between ages 5 and 15 (hazard ratio [HR], 0.62; 95% confidence interval [CI], 0.40-0.96; P = .034), and living with a large family size in the first year of life (HR, 0.43; 95% CI, 0.21-0.85; P = .016) were associated with decreased CD risk, whereas having a bird at the time of recruitment (HR, 2.78; 95% CI, 1.36-5.68; P = .005) was associated with an increased CD risk. Furthermore, living with a dog was associated with reduced LMR, altered relative abundance of multiple bacterial genera, and increased Chao1 diversity, whereas bird owners had higher FCP levels. Large family during participants' first year of life was associated with altered microbiota composition without affecting FCP or LMR. CONCLUSION: This study identifies environmental variables associated with CD risk. These variables were also associated with altered barrier function, subclinical inflammation, and gut microbiome composition shifts, suggesting potential roles in CD pathogenesis.

Forecasting the Incidence and Prevalence of Inflammatory Bowel Disease: A Canadian Nationwide Analysis.

INTRODUCTION: Canada has a high burden of inflammatory bowel disease (IBD). Historical trends of IBD incidence and prevalence were analyzed to forecast the Canadian burden over the next decade. METHODS: Population-based surveillance cohorts in 8 provinces derived from health administrative data assessed the national incidence (2007-2014) and prevalence (2002-2014) of IBD. Autoregressive integrated moving average models were used to forecast incidence and prevalence, stratified by age, with 95% prediction intervals (PI), to 2035. The average annual percentage change (AAPC) with 95% confidence interval (CI) was calculated for the forecasted incidence and prevalence. RESULTS: The national incidence of IBD is estimated to be 29.9 per 100,000 (95% PI 28.3-31.5) in 2023. With a stable AAPC of 0.36% (95% CI -0.05 to 0.72), the incidence of IBD is forecasted to be 31.2 per 100,000 (95% PI 28.1-34.3) in 2035. The incidence in pediatric patients (younger than 18 years) is increasing (AAPC 1.27%; 95% CI 0.82-1.67), but it is stable in adults (AAPC 0.26%; 95% CI -0.42 to 0.82). The prevalence of IBD in Canada was 843 per 100,000 (95% PI 716-735) in 2023 and is expected to steadily climb (AAPC 2.43%; 95% CI 2.32-2.54) to 1,098 per 100,000 (95% PI 1,068-1,127) by 2035. The highest prevalence is in seniors with IBD (1,174 per 100,000 in 2023; AAPC 2.78%; 95% CI 2.75-2.81). DISCUSSION: Over the next decade, the Canadian health care systems will contend with the juxtaposition of rising incidence of pediatric IBD and a rising prevalence of overall IBD driven by the aging population.

Health Care Utilization and Direct Costs Prior to Subspecialty Care in Children with Chronic Pain Compared with Other Chronic Childhood Diseases: A Cohort Study.

OBJECTIVES: To understand the burden associated with pediatric chronic pain (CP) on the health care system compared with other costly chronic diseases prior to subspecialty care. STUDY DESIGN: In this retrospective cohort study, we assessed all-cause health care utilization and direct health care costs associated with pediatric CP (n = 91) compared with juvenile arthritis (n = 135), inflammatory bowel disease (n = 90), type 1 diabetes (n = 475) or type 2 diabetes (n = 289), anxiety (n = 7193), and controls (n = 273) 2 and 5 years prior to patients entering subspecialty care in Manitoba, Canada. Linked data from physician encounters, emergency department visits, hospitalizations, and prescriptions were extracted from administrative databases. Differences in health care utilization and direct health care costs associated with CP vs the other conditions were tested using negative binomial and zero-inflated negative binomial regression models, respectively. RESULTS: After adjustment for age at diagnosis, sex, location of residence, and socioeconomic status, CP continued to be associated with the highest number of consulted physicians and subspecialists and the highest number of physician billings compared with all other conditions (P < .01, respectively). CP was significantly associated with higher physician costs than juvenile arthritis, inflammatory bowel disease, type 1 diabetes, type 2 diabetes, or controls (P < .01, respectively); anxiety was associated with the highest physician and prescription costs among all cohorts (P < .01, respectively). CONCLUSION: Compared with chronic inflammatory and endocrinologic conditions, pediatric CP and anxiety were associated with substantial burden on the health care system prior to subspecialty care, suggesting a need to assess gaps and resources in the management of CP and mental health conditions in the primary care setting.

ADALIMUMAB VERSUS INFLIXIMAB IN LUMINAL PEDIATRIC CROHN'S DISEASE: COMPARABLE OUTCOMES IN A PROSPECTIVE MULTICENTER COHORT STUDY.

BACKGROUND: This study compared real-world effectiveness between adalimumab (ADA) and infliximab (IFX) in children with Crohn's disease (CD). METHODS: Children enrolled into the prospective Canadian Children Inflammatory Bowel Disease Network (CIDsCaNN) National Inception Cohort between 2014 and 2020 who commenced ADA or IFX as first anti-tumor necrosis factor (antiTNF) agent for luminal CD were included. Multivariate logistic regression modelled the propensity of commencing ADA; propensity score matching was used to match IFX-treated children to ADA-treated children. The primary outcome at one year was steroid-free clinical remission (SFCR). Secondary outcomes at one year were I) combined SFCR and c-reactive protein (CRP) remission; II) treatment intensification; and III) antiTNF durability. Odds ratios (aOR) and hazard ratio (aHR) adjusted for concomitant immunomodulator use with 95% confidence interval (CI) are reported. RESULTS: In the propensity score matched cohort of 147 ADA-treated and 147 IFX-treated children, 92 (63%) ADA- and 87 (59%) IFX-treated children achieved SFCR at one year (aOR: 1.4, 95% CI 0.9-2.4); 75 of 140 (54%) ADA- and 85 of 144 (59%) IFX-treated children achieved combined SFCR and CRP remission (aOR: 1.0, 95% CI 0.6-1.6). ADA-treated children less frequently underwent treatment intensification (21 [14%]) compared to IFX-treated children (69 [47%]) (P<0.0001). Discontinuation of antiTNF occurred in 18 (12%) ADA-treated and 15 (10%) IFX-treated children (aHR: 1.2, 95% CI 0.6-2.2). CONCLUSION: Children with Crohn's disease achieved favourable outcomes at one year with either ADA or IFX as first antiTNF agents. Those receiving IFX did not have significantly superior outcomes compared to clinically similar children receiving ADA.

Transition Readiness in Youth with Inflammatory Bowel Disease.

OBJECTIVES: To examine readiness of adolescents and young adults (AYAs) with inflammatory bowel disease (IBD) to transition to adult care. STUDY DESIGN: A cross-sectional multicenter study evaluating transition readiness in individuals with IBD 16-19 years old prospectively recruited from 8 Canadian IBD centers using the validated ON Taking Responsibility for Adolescent to Adult Care (ON TRAC) questionnaire. Secondary aims included (1) screening for depression and anxiety using the 8-item Personal Health Questionnaire Depression Scale and The Screen for Child Anxiety Related Emotional Disorders questionnaires, respectively; (2) evaluating the association between depression and anxiety with readiness and disease activity; and (3) subjectively evaluating AYA readiness based on physician and parent assessments. RESULTS: In total, 186 participants (139 adolescent, 47 young adult) were enrolled, mean age 17.4 years (SD, 0.87). ON TRAC scores determined that 26.6% of AYAs at pediatric and 40.4% at adult centers reached the threshold of readiness. On multivariable linear regression analysis age was positively (P = .001) and disease remission negatively (P = .03) associated with ON TRAC scores. No statistically significant differences were determined across centers. A significant percentage of AYAs reported moderate-to-severe depression (21.7%) and generalized anxiety (36%); however, neither were significantly associated with ON TRAC scores. Notably, physician and parental assessment of AYA readiness correlated poorly with ON TRAC scores (⍴ = 0.11, ⍴ = 0.24, respectively). CONCLUSIONS: Assessment of transition readiness in AYAs with IBD highlighted that a large proportion do not have adequate knowledge or behavior skills needed for transition to adult care. This study infers that readiness assessment tools are essential during transition to identify deficits in knowledge and behavior skills that could be specifically targeted by the youth, caregivers, and multidisciplinary team.

Oral Vancomycin, Ursodeoxycholic Acid, or No Therapy for Pediatric Primary Sclerosing Cholangitis: A Matched Analysis.

BACKGROUND AND AIMS: Many children with primary sclerosing cholangitis (PSC) receive oral vancomycin therapy (OVT) or ursodeoxycholic acid (UDCA). There is a paucity of data on whether these medications improve outcomes. APPROACH AND RESULTS: We analyzed retrospective data from the Pediatric PSC Consortium. Children treated with OVT were matched 1:1:1 to those treated with UDCA or managed with observation (no treatment) based on the closest propensity score, ensuring similar baseline characteristics. Two hundred sixty-four patients (88 each with OVT, UDCA, or observation) had matching propensity scores and were similar in demographics, phenotype, immunosuppression, baseline biochemistry, and hepatic fibrosis. After 1 year in an intention-to-treat analysis, all outcome metrics were similar regardless of treatment group. In OVT, UDCA, and untreated groups, respectively: Gamma-glutamyltransferase normalized in 53%, 49%, and 52% (P = not significant [NS]), liver fibrosis stage was improved in 20%, 13%, and 18% and worsened in 11%, 29%, and 18% (P = NS), and the 5-year probability of liver transplant listing was 21%, 10%, and 12% (P = NS). Favorable outcome was associated with having a mild phenotype of PSC and minimal hepatic fibrosis. CONCLUSIONS: We presented the largest-ever description of outcomes on OVT in PSC and compared them to carefully matched patients on UDCA or no therapy. Neither OVT nor UDCA showed improvement in outcomes compared to a strategy of observation. Patients progressed to end-stage liver disease at similar rates. Spontaneous normalization of biochemistry is common in children receiving no therapy, particularly in the majority of children with a mild phenotype and an early stage of disease. Placebo-controlled treatment trials are needed to identify effective treatments for pediatric PSC.

The Sclerosing Cholangitis Outcomes in Pediatrics (SCOPE) Index: A Prognostic Tool for Children.

BACKGROUND AND AIMS: Disease progression in children with primary sclerosing cholangitis (PSC) is variable. Prognostic and risk-stratification tools exist for adult-onset PSC, but not for children. We aimed to create a tool that accounts for the biochemical and phenotypic features and early disease stage of pediatric PSC. APPROACH AND RESULTS: We used retrospective data from the Pediatric PSC Consortium. The training cohort contained 1,012 patients from 40 centers. We generated a multivariate risk index (Sclerosing Cholangitis Outcomes in Pediatrics [SCOPE] index) that contained total bilirubin, albumin, platelet count, gamma glutamyltransferase, and cholangiography to predict a primary outcome of liver transplantation or death (TD) and a broader secondary outcome that included portal hypertensive, biliary, and cancer complications termed hepatobiliary complications (HBCs). The model stratified patients as low, medium, or high risk based on progression to TD at rates of <1%, 3%, and 9% annually and to HBCs at rates of 2%, 6%, and 13% annually, respectively (P < 0.001). C-statistics to discriminate outcomes at 1 and 5 years were 0.95 and 0.82 for TD and 0.80 and 0.76 for HBCs, respectively. Baseline hepatic fibrosis stage was worse with increasing risk score, with extensive fibrosis in 8% of the lowest versus 100% with the highest risk index (P < 0.001). The model was validated in 240 children from 11 additional centers and performed well. CONCLUSIONS: The SCOPE index is a pediatric-specific prognostic tool for PSC. It uses routinely obtained, objective data to predict a complicated clinical course. It correlates strongly with biopsy-proven liver fibrosis. SCOPE can be used with families for shared decision making on clinical care based on a patient's individual risk, and to account for variable disease progression when designing future clinical trials.

Indirect and Out-of-Pocket Disease-associated Costs in Pediatric Inflammatory Bowel Disease: A Cross-sectional Analysis.

OBJECTIVES: Data on pediatric inflammatory bowel disease (IBD)-associated indirect and out-of-pocket (OOP) costs are limited. We aimed to estimate indirect (lost work hours and productivity) and OOP pediatric IBD-associated costs in Canada. METHODS: In a nation-wide cross-sectional analysis, caregivers of children with IBD were invited to complete a questionnaire on lost work hours and OOP costs related to IBD in the 4 weeks prior to the survey. Participants were reinvited to periodically answer the same questionnaire every 3-9 months for 2 years. Lost productivity was calculated using the Human Capital method. Costs were reported in 2018 inflation-adjusted Canadian dollars. Predictors of high cost users (top 25%) were examined using binary logistic regression. RESULTS: Consecutive 243 (82 incident cases) of 262 (92.7%) approached participants completed the first survey with a total of 450 surveys longitudinally completed over 2 years. The median annual indirect cost per patient was $5966 (IQR $1809-$12,676), with $5721 (IQR $1366-$11,545) for Crohn's disease (CD) and $7007 (IQR $2428-$14,057) for ulcerative colitis (UC) ( P = 0.11). The annual median per patient OOP costs were $4550 with $4550 for CD and $5038 for UC ( P = 0.53). Longer travel distance to clinic was associated with higher OOP costs (odds ratio = 4.55; P < 0.0001; 95% confidence interval: 1.99-10.40). CONCLUSIONS: Indirect and OOP IBD-associated costs are substantial and more likely to affect families living in remote communities.

Hospitalization With Clostridioides difficile in Pediatric Inflammatory Bowel Disease: a Population-Based Study.

OBJECTIVES: Several studies have demonstrated higher rates of Clostridioides difficile infection (CDI) in adults with inflammatory bowel disease (IBD). We conducted a population-based study comparing the risk of hospitalization with CDI in children with and without IBD. METHODS: Using health administrative data and validated algorithms, we identified all children (<16 years) diagnosed with IBD in 5 Canadian provinces, then age and sex matched to 5 children without IBD. Province-specific 5-year incidence rates of hospitalization with CDI were pooled and generalized linear mixed-effects models were used to estimate the crude incidence rate ratio (IRR) comparing (1) children with and without IBD and (2) children with Crohn disease and ulcerative colitis. Hazard ratios (HR) from Cox proportional hazards models adjusting for age, sex, rural/urban household, and income were pooled using fixed-effects models. RESULTS: The incidence rate of CDI identified during hospitalization was 49.06 [95% confidence interval (CI), 39.40-61.08] per 10,000 person-years (PY) in 3593 children with IBD compared to 0.39 (95% CI, 0.13-1.21) per 10,000 PY in 16,284 children without IBD (crude IRR, 133.4, 95% CI, 42.1-422.7; adjusted HR, 68.2, 95% CI, 24.4-190.4). CDI was identified less often in children with Crohn disease than ulcerative colitis (crude IRR, 0.51, 95% CI, 0.32-0.82; adjusted HR, 0.69, 95% CI, 0.46-1.05). CONCLUSIONS: Children with IBD have a markedly higher incidence of CDI identified during a hospitalization relative to children without IBD. Consequently, symptomatic children with IBD who are hospitalized should be screened for CDI.

Colorectal Dysplasia and Cancer in Pediatric-Onset Ulcerative Colitis Associated With Primary Sclerosing Cholangitis.

Inflammatory bowel disease (IBD), especially when associated with primary sclerosing cholangitis (PSC), is a risk factor for developing colorectal cancer (CRC).1-3 We aimed to determine the incidence of CRC in a large cohort of pediatric-onset PSC-ulcerative colitis (UC) patients.

Increased Incidence of Inflammatory Bowel Disease After Hirschsprung Disease: A Population-based Cohort Study.

OBJECTIVE: To determine the frequency with which inflammatory bowel disease (IBD) is diagnosed in persons with Hirschsprung disease in population-based datasets from 3 Canadian provinces. STUDY DESIGN: In study I, Ontario data were used to assess the incidence of IBD in a birth cohort of children with Hirschsprung disease relative to children without Hirschsprung disease. In study II, a case-control design was used in Alberta and Manitoba to determine the frequency of previously diagnosed Hirschsprung disease in persons with IBD, compared with the frequency of Hirschsprung disease in matched controls. Validated algorithms for Hirschsprung disease and IBD were applied to each provincial health registry. RESULTS: In study I, of the 716 children diagnosed with Hirschsprung disease in Ontario since 1991, 18 (2.5%) ultimately developed IBD (168.8 per 100 000 person-years), compared with 7109 of 3 377 394 children without Hirschsprung disease (0.2%, 14.2 per 100 000 person-years). The percentage of males with post-Hirschsprung disease IBD was 77.8%. The incidence rate ratio was 11.9 (95% CI, 7.5-18.8). In study II, the OR of having had Hirschsprung disease before a diagnosis of IBD compared with controls was 74.9 (95% CI, 17.1-328.7) in Alberta and 23.8 (95% CI, 4.6-123) in Manitoba. Crohn's disease was more common after Hirschsprung disease than ulcerative colitis. CONCLUSIONS: IBD can emerge in more than 2% of patients with Hirschsprung disease and, like Hirschsprung disease itself, is more common in males. IBD is much more common after a diagnosis of Hirschsprung disease than in the general population.

Canadian Association of Gastroenterology Clinical Practice Guideline for the Medical Management of Pediatric Luminal Crohn's Disease.

BACKGROUND & AIMS: We aim to provide guidance for medical treatment of luminal Crohn's disease in children. METHODS: We performed a systematic search of publication databases to identify studies of medical management of pediatric Crohn's disease. Quality of evidence and strength of recommendations were rated according to the GRADE (Grading of Recommendation Assessment, Development, and Evaluation) approach. We developed statements through an iterative online platform and then finalized and voted on them. RESULTS: The consensus includes 25 statements focused on medical treatment options. Consensus was not reached, and no recommendations were made, for 14 additional statements, largely due to lack of evidence. The group suggested corticosteroid therapies (including budesonide for mild to moderate disease). The group suggested exclusive enteral nutrition for induction therapy and biologic tumor necrosis factor antagonists for induction and maintenance therapy at diagnosis or at early stages of severe disease, and for patients failed by steroid and immunosuppressant induction therapies. The group recommended against the use of oral 5-aminosalicylate for induction or maintenance therapy in patients with moderate disease, and recommended against thiopurines for induction therapy, corticosteroids for maintenance therapy, and cannabis in any role. The group was unable to clearly define the role of concomitant immunosuppressants during initiation therapy with a biologic agent, although thiopurine combinations are not recommended for male patients. No consensus was reached on the role of aminosalicylates in treatment of patients with mild disease, antibiotics or vedolizumab for induction or maintenance therapy, or methotrexate for induction therapy. Patients in clinical remission who are receiving immunomodulators should be assessed for mucosal healing within 1 year of treatment initiation. CONCLUSIONS: Evidence-based medical treatment of Crohn's disease in children is recommended, with thorough ongoing assessments to define treatment success.

Obesity Is More Common in Children Newly Diagnosed With Ulcerative Colitis as Compared to Those With Crohn Disease.

OBJECTIVE: This prospective observational study aimed to examine the prevalence of obesity in a population-based cohort of children and young adults newly diagnosed with inflammatory bowel disease (IBD) and assess their outcome in comparison to newly diagnosed normal/underweight patients. METHODS: Our longitudinal population-based cohort comprised all children younger than 17 years diagnosed with IBD in the province of Manitoba, Canada between 2012 and 2018. Cox regression model with adjustment for a priori covariates was used to examine the time to first relapse among patients who were obese/overweight at the time of IBD diagnosis in comparison to patients who were normal or underweight. RESULTS: A total of 139 patients with IBD were followed up for a median duration of 1.09 (interquartile range: 0.53-2.62) years. Obesity was more common in children newly diagnosed with ulcerative colitis (UC) compared to those with Crohn disease (CD) (12.7% vs 0.0%; P = 0.005). Age at diagnosis poorly correlated with the body mass index z score (R = 0.23; P = 0.01). The proportions of patients who were underweight at the time of IBD diagnosis among patients with UC and CD were 6.3% and 20.0%, respectively (P = 0.01). The time to initial relapse was not found to be significantly associated with weight category at diagnosis in UC (adjusted hazard ratio = 0.77; 95% confidence interval: 0.40-1.63) or CD (adjusted hazard ratio  = 0.83; 95% confidence interval: 0.20-3.51). CONCLUSION: Obesity was more common in children and young adults newly diagnosed with UC. The majority of the underweight children had CD.

Discontinuation of Immunosuppressive Medications in Children With Inflammatory Bowel Disease on Combination Therapy.

We determined the frequency and factors associated with the first clinical relapse after immunomodulator (IM) withdrawal in a cohort of children with inflammatory bowel disease on combination therapy. A total of 105 patients (89 with Crohn disease [CD]) in clinical remission were included (91 [86.7%] were on infliximab, 53 [50.5%] with methotrexate, and 52 on azathioprine). The median duration of combination therapy was 2.1 years (interquartile range [IQR] 1.3-2.8). Only 11 (10.5%) patients experienced a clinical relapse over a median duration of follow-up of 12.0 months (IQR 5.0-19.0) after IM discontinuation. The median baseline pediatric CD activity index in those with CD who relapsed after IM discontinuation was 47.5 (IQR: 35.0-55.0) versus those who did not relapse (median 35.0, IQR: 20.0-52.5; P = 0.04). In the patients who did not relapse, the median IFX trough level at IM discontinuation was 6.2 and 3.8 µg/mL in those who relapsed.

Assessing the Validity of Adult-derived Prognostic Models for Primary Sclerosing Cholangitis Outcomes in Children.

BACKGROUND: Natural history models for primary sclerosing cholangitis (PSC) are derived from adult patient data, but have never been validated in children. It is unclear how accurate such models are for children with PSC. METHODS: We utilized the pediatric PSC consortium database to assess the Revised Mayo Clinic, Amsterdam-Oxford, and Boberg models. We calculated the risk stratum and predicted survival for each patient within each model using patient data at PSC diagnosis, and compared it with observed survival. We evaluated model fit using the c-statistic. RESULTS: Model fit was good at 1 year (c-statistics 0.93, 0.87, 0.82) and fair at 10 years (0.78, 0.75, 0.69) in the Mayo, Boberg, and Amsterdam-Oxford models, respectively. The Mayo model correctly classified most children as low risk, whereas the Amsterdam-Oxford model incorrectly classified most as high risk. All of the models underestimated survival of patients classified as high risk. Albumin, bilirubin, AST, and platelets were most associated with outcomes. Autoimmune hepatitis was more prevalent in higher risk groups, and over-weighting of AST in these patients accounted for the observed versus predicted survival discrepancy. CONCLUSIONS: All 3 models offered good short-term discrimination of outcomes but only fair long-term discrimination. None of the models account for the high prevalence of features of autoimmune hepatitis overlap in children and the associated elevated aminotransferases. A pediatric-specific model is needed. AST, bilirubin, albumin, and platelets will be important predictors, but must be weighted to account for the unique features of PSC in children.

Inflammatory Bowel Disease in Children with Elevated Serum Gamma Glutamyltransferase Levels.

OBJECTIVE: To assess the characteristics of inflammatory bowel disease and disease prognosis among children with elevated gamma glutamyltransferase (GGT) and primary sclerosing cholangitis (PSC)-ulcerative colitis (UC). STUDY DESIGN: Our longitudinal, population-based cohort comprised all children and young adults diagnosed with UC in the Canadian province of Manitoba between 2011 and 2018. Diagnosis of PSC was confirmed based on a combination of cholestatic biochemical markers and cholangiographic features. The Fisher exact test with Bonferroni correction was used to examine the relationship between categorical variables. RESULTS: We enrolled 95 children with UC/Inflammatory bowel disease-unclassified with a median age at diagnosis of 14 years (IQR: 10.4-15.9 years) and 1399 person-years follow-up. Among them, 9 children developed PSC-UC, with an incidence rate of 6.43 new cases per 1000 person-years. In this cohort, 8 (72.7%) of 11 children with high baseline serum GGT levels developed PSC-UC in comparison with 1 (1.2%) of 84 children with normal serum GGT levels at baseline (P < .001). All children with high serum GGT levels at diagnosis had pancolitis in comparison with 63.9% of children with normal serum GGT levels (P = .01). Children with high serum GGT levels were more likely to be perinuclear neutrophil antibodies-positive than those with normal levels (90.9% vs 52.0%, P = .01). CONCLUSIONS: Our findings indicated that pediatric patients with UC and with even mild elevations of serum GGT levels, especially at baseline, might be predisposed to develop PSC.

Trends and Predictors of Clostridium difficile Infection among Children: A Canadian Population-Based Study.

OBJECTIVE: To assess time trends in Clostridium difficile infection (CDI) rates, and predictors of CDIs, including recurrent CDIs, in children. STUDY DESIGN: Data were extracted from Manitoba Health Provider Claims, and other population registry datasets from 2005 to 2015. CDI was identified from the Manitoba Health Public Health Branch Epidemiology and Surveillance population-based laboratory-confirmed CDI dataset. Children aged 2-17 years with CDI were matched by age, sex, area of residence, and duration of residence in Manitoba with children without CDI. The rates and time trends of CDIs using previously recommended definitions were determined. Predictors of CDI subtypes were determined using multivariable logistic regression models. Cox regression analysis was used to assess for the potential predictors of recurrent CDI. RESULTS: Children with and without CDI were followed for 828 and 2753 persons-years, respectively. The overall CDI rate during the study period was 7.8 per 100 000 person-years. There was no significant change in CDI rates over the observation period. Comorbid conditions, more prevalent among children with CDI than matched controls, included Hirschsprung disease (P < .001) and inflammatory bowel disease (P < .0001). Recurrent CDIs (>2 occurrences) were responsible for 10% of CDI episodes (range, 2-6 infections). Predictors of recurrence included malignancy (hazard ratio, 3.0, 95% CI, 1.1-8.8), diabetes (hazard ratio, 4.8; 95% CI, 1.1-21.4), and neurodegenerative diseases (hazard ratio, 8.4; 95% CI, 1.9-37.5). CONCLUSIONS: The incidence of CDI is stable among children in Manitoba. Children with Hirschsprung disease and inflammatory bowel disease are more susceptible to CDI, and those with malignancy, diabetes. and neurodegenerative disorders are more likely to develop recurrent CDI.

Ursodeoxycholic Acid Therapy in Pediatric Primary Sclerosing Cholangitis: Predictors of Gamma Glutamyltransferase Normalization and Favorable Clinical Course.

OBJECTIVE: To investigate patient factors predictive of gamma glutamyltransferase (GGT) normalization following ursodeoxycholic acid (UDCA) therapy in children with primary sclerosing cholangitis. STUDY DESIGN: We retrospectively reviewed patient records at 46 centers. We included patients with a baseline serum GGT level ≥50 IU/L at diagnosis of primary sclerosing cholangitis who initiated UDCA therapy within 1 month and continued therapy for at least 1 year. We defined "normalization" as a GGT level <50 IU/L without experiencing portal hypertensive or dominant stricture events, liver transplantation, or death during the first year. RESULTS: We identified 263 patients, median age 12.1 years at diagnosis, treated with UDCA at a median dose of 15 mg/kg/d. Normalization occurred in 46%. Patients with normalization had a lower prevalence of Crohn's disease, lower total bilirubin level, lower aspartate aminotransferase to platelet ratio index, greater platelet count, and greater serum albumin level at diagnosis. The 5-year survival with native liver was 99% in those patients who achieved normalization vs 77% in those who did not. CONCLUSIONS: Less than one-half of the patients treated with UDCA have a complete GGT normalization in the first year after diagnosis, but this subset of patients has a favorable 5-year outcome. Normalization is less likely in patients with a Crohn's disease phenotype or a laboratory profile suggestive of more advanced hepatobiliary fibrosis. Patients who do not achieve normalization could reasonably stop UDCA, as they are likely not receiving clinical benefit. Alternative treatments with improved efficacy are needed, particularly for patients with already-advanced disease.

Clinical disease activity and endoscopic severity correlate poorly in children newly diagnosed with Crohn's disease.

BACKGROUND AND AIMS: Treatment goals in Crohn's disease (CD) have evolved to target mucosal healing. There is now a drive to determine if noninvasive measures can adequately identify the attainment and persistence of this goal. Currently, data describing the relationship between clinical indices and endoscopic appearance in pediatric CD are sparse. Our aim was to compare endoscopic severity with the weighted Pediatric Crohn's Disease Activity Index (wPCDAI) in children with newly diagnosed CD. METHODS: All children aged ≤17 years newly diagnosed with CD enrolled in an inception cohort at sites of the Canadian Children Inflammatory Bowel Disease Network were eligible. Clinical disease activity at presentation was evaluated by the wPCDAI and conventional biochemical parameters. Severity of disease at ileocolonoscopy was assessed by the simple endoscopic score for CD (SES-CD), with segmental subscores noted. We evaluated the association of SES-CD and disease activity markers using the Pearson test of correlation, the Spearman rank coefficient, and linear regression models. RESULTS: Two hundred eighty patients from 11 centers were included in the analysis. The median wPCDAI score was 60 (interquartile range, 40-80; 53% severe). Median SES-CD was 16 (interquartile range 10-22; 51% severe). The wPCDAI correlated weakly with SES-CD (r = .39, P < .001). Examination of the individual components that contribute to the wPCDAI demonstrated weak correlation with the SES-CD for all items apart from stooling (moderate correlation, r = .50, P < .001). Routine blood tests did not correlate well with the SES-CD. In regression models, variation in clinical symptoms accounted for most of the variation in both the wPCDAI and SES-CD, with no additional benefit from routine blood tests. CONCLUSIONS: In children with newly diagnosed CD, wPCDAI correlates poorly with endoscopic disease activity. As treatment paradigms evolve to target mucosal healing, clinical markers should not be used in isolation to determine disease activity.