The Phenotypic Spectrum of New-onset IBD in Canadian Children of South Asian Ethnicity: A Prospective Multi-Centre Comparative Study.

BACKGROUND: Canadian-born children of South Asian [SA] ethnicity develop inflammatory bowel disease [IBD] at similar rates to those among Caucasian children. We evaluated the variation in phenotypic spectrum of IBD in SA and Caucasian children in a national paediatric inception cohort of new-onset IBD. METHODS: Patients aged <17 years, enrolled in a Canadian nationwide inception cohort study, were included. Baseline demographic and IBD phenotypic features were compared between SA and Caucasian children. Longitudinal outcomes through 18 months of follow-up were compared matched by propensity scores. RESULTS: Of 1156 children enrolled over 2014 to 2019, 623 were Caucasian [98% and 88% parents Canadian born] and 114 SA [79% Canadian born, 87% parents SA born]. Fewer SAs have a first-degree relative with IBD, 6% vs 19% in Caucasians, p = 0.002. SAs present at a younger age, median age 11.4 years (interquartile range [IQR] 9.2-14.3) vs 13 years [IQR 10.9-15 years], p = 0.03 and more commonly with a UC/IBD-U [ulcerative colitis/IBD-unclassified] subtype [ratio of UC/IBD-U to CD 1.2:1 vs 1:1.8 for Caucasians, p <0.001]. Additionally, a greater proportion of SA CD patients present with colonic-only disease [colonic-only CD/UC/IBD-U in SAs 67% vs 57% for Caucasians, p = 0.001], and among those with CD, colonic CD in SAs 31% vs 23% in Caucasians, p = 0.20]. Perianal fistulising disease was also numerically more common in SAs (14 [27%] vs 64 [18%], p = 0.06]. Adjusting for differences in phenotypic presentation, anti-tumour necrosis factor [TNF] exposure, and time to initiation was similar, and two-thirds of children, whether anti-TNF exposed or naïve, were in corticosteroid-free clinical remission at 18 months irrespective of ethnicity. CONCLUSIONS: The phenotypic spectrum of new-onset IBD in SA children differs from that of Caucasian children, but treatment and clinical course are similar within phenotypic subgroups.

Phenotypic Variation in Paediatric Inflammatory Bowel Disease by Age: A Multicentre Prospective Inception Cohort Study of the Canadian Children IBD Network.

BACKGROUND AND AIMS: Incidence of paediatric inflammatory bowel disease [IBD] in Canada is among the highest worldwide, and age of onset may be decreasing. In a multicentre nationwide inception cohort study, we examined variation in phenotype of IBD throughout the paediatric age spectrum. METHODS: Children aged ≥2 years [y] and <17y [A1 age at diagnosis], with new onset IBD, were systematically evaluated at sites of the Canadian Children IBD Network. Prospectively recorded phenotypic data were compared between age groups. RESULTS: Among 1092 children (70% Caucasian; 64% Crohn's disease [CD], 36% ulcerative colitis/inflammatory bowel disease unclassified [UC/IBD-U]; median age 13 y, interquartile range [IQR] 11-15 y), 210 [19%] were diagnosed before the age of age 10 y [Paris A1a] and 43 [4%] before age 6 y (very-early-onset [VEO-IBD]). CD was less common in younger children [42%, 56%, 66%, respectively, of VEO-IBD, A1a; A1b]. Colon-only IBD [UC/IBDU or CD-colon] was present in 81% of VEO-IBD and 65% of A1a; ileal disease increased progressively, reaching plateau at age 10 y. CD location was ileocolonic [L3] in 53% overall. Ileitis [L1] increased with age [6% of VEO-IBD; 13% of A1a; 21% of A1b], as did stricturing/penetrating CD [4% of A1a; 11% of A1b]. At all ages UC was extensive [E3/E4] in >85%, and disease activity moderate to severe according to Physician's Global Assessment [PGA] and weighted Paediatric Crohn's Disease Activity Index/Paediatric Ulcerative Colitis Activity Index [wPCDAI/PUCAI] in >70%. Heights were modestly reduced in CD [mean height z score -0.30 ± 1.23], but normal in UC/IBD-U. CONCLUSIONS: Paris classification of age at diagnosis is supported by age-related increases in ileal disease until age 10 years. Other phenotypic features, including severity, are similar across all ages. Linear growth is less impaired in CD than in historical cohorts, reflecting earlier diagnosis.

Musculoskeletal health in newly diagnosed children with Crohn's disease.

We evaluated the impact of Crohn's disease on muscle and bone strength, mass, density, and geometry in children with newly diagnosed CD and found profound muscle and bone deficits; nevertheless, the prevalence of vertebral fractures at this time point was low. INTRODUCTION: Crohn's disease (CD) is an inflammatory condition of the gastrointestinal tract that can affect the musculoskeletal system. The objective of this study was to determine the prevalence of vertebral fractures and the impact of CD on muscle and bone mass, strength, density, and geometry in children with newly diagnosed CD. METHODS: Seventy-three children (26 girls) aged 7.0 to 17.7 years were examined within 35 days following CD diagnosis by lateral spine radiograph for vertebral fractures and by jumping mechanography for muscle strength. Bone and muscle mass, density, and geometry were assessed by dual-energy x-ray absorptiometry and peripheral quantitative computed tomography (pQCT). RESULTS: Disease activity was moderate to severe in 66 (90%) patients. Mean height (Z-score -0.3, standard deviation (SD) 1.1, p = 0.02), weight (Z-score -0.8, SD 1.3, p < 0.01), body mass index (Z-score -1.0, SD 1.3, p < 0.01), lumbar spine areal bone mineral density (BMD; Z-score -1.1, SD 1.0, p < 0.01), total body bone mineral content (Z-score -1.5, SD 1.0, p < 0.01), and total body lean mass (Z-score -2.5, SD 1.1, p < 0.01) were all low for age and gender. pQCT showed reduced trabecular volumetric BMD at the tibial metaphysis, expansion of the bone marrow cavity and thin cortices at the diaphysis, and low calf muscle cross-sectional area. Jumping mechanography demonstrated low muscle power. Only one patient had a vertebral fracture. CONCLUSIONS: Children with newly diagnosed CD have profound muscle and bone deficits; nevertheless, the prevalence of vertebral fractures at this time point was low.

Review article: a clinician's guide for therapeutic drug monitoring of infliximab in inflammatory bowel disease.

BACKGROUND: Tumour necrosis factor (TNF)-antagonists have an established role in the treatment of inflammatory bowel diseases (IBDs), however, subtherapeutic drug levels and the formation of anti-drug antibodies (ADAs) may decrease their efficacy. AIM: The evidence supporting the use of therapeutic drug monitoring (TDM) based clinical algorithms for infliximab (IFX) and their role in clinical practice will be discussed. METHODS: The literature was reviewed to identify relevant articles on the measurement of IFX levels and antibodies-to-infliximab. RESULTS: Treatment algorithms for IBD have evolved from episodic monotherapy used in patients refractory to all other treatments, to long-term combination therapy initiated early in the disease course. Improved remission rates have been observed with this paradigm shift, nevertheless many patients ultimately lose response to therapy. Although empiric dose optimization or switching agents constitute the current standard of care for secondary failure, these interventions have not been applied in an evidence-based manner and are probably not cost-effective. Multiple TDM-based algorithms have been developed to identify patients that may benefit from measurement of IFX and ADA levels to guide adjustments to therapy. CONCLUSIONS: Therapeutic drug monitoring offers a rational approach to the management of secondary failure to IFX. This concept has gained momentum based on evidence from case series, cohort studies and post-hoc analyses of randomised controlled trials.

Iliac bone histomorphometry in children with newly diagnosed inflammatory bowel disease.

UNLABELLED: Children with inflammatory bowel disease (IBD) manifest low bone mass; the cause remains unclear. We performed transilial bone biopsies in 20 IBD children at diagnosis and found a mild cortical bone deficit and slow bone turnover. It is possible that low mechanical stimulation due to inadequate muscle mass contributes to the bone deficit. INTRODUCTION: Children with newly diagnosed IBD can have low bone mineral density and disturbed bone metabolism, but the tissue level characteristics of the bone involvement in pediatric IBD have not been elucidated. METHODS: In the present study, we evaluated the skeletal status, including static histomorphometry on transiliac bone samples, in 20 patients (age range 8.4 to 17.7 years, 12 boys) with newly diagnosed IBD and compared results to published normative data. RESULTS: Despite normal height (mean Z-score 0.04, SD 1.2), areal bone mineral density at the lumbar spine was moderately low (mean age- and sex-specific Z-score -0.8, SD 1.1). Total body bone mineral content and lean mass were low for age and sex as well (mean Z-scores -1.2, SD 0.9 and -2.0, SD 0.9, respectively). Biochemical bone markers indicated low bone formation and resorption activity. Bone histomorphometry revealed a slightly low cortical width (mean 23%, SD 25%, below the result expected for age) but a normal amount of trabecular bone. The percentage of trabecular bone surface covered by osteoid or osteoclasts was low, suggesting that both bone formation and bone resorption were suppressed. CONCLUSIONS: Our results indicate that young patients manifest a mild cortical bone deficit at the iliac crest and slow trabecular bone turnover even at diagnosis, in the setting of IBD.

Pico-Salax versus polyethylene glycol for bowel cleanout before colonoscopy in children: a randomized controlled trial.

BACKGROUND AND STUDY AIMS: Comparison of bowel preparation for colonoscopy in children with either Pico-Salax (sodium picosulphate with magnesium citrate) or polyethylene glycol with electrolyte solution (PEG-ELS). PATIENTS AND METHODS: In this investigator-blinded, randomized controlled trial, 83 children (12.5 +/- 3.1 years) requiring elective colonoscopy at a referral hospital were randomly allocated to Pico-Salax (n = 43) or PEG-ELS (n = 40), and an intention-to treat analysis was applied. Pico-Salax was administered in two doses, one the evening before and one on the morning of the procedure. PEG-ELS was administered over 4 hours. Efficacy was scored using the Ottawa scale and other constructs. Tolerability and toxicity were measured by patient and nursing questionnaires and serum biochemistry. RESULTS: 35 of Pico-Salax patients (81 %) were satisfied or very satisfied with the cleanout, compared with 19 (48 %) in the PEG-ELS group (P = 0.001). No differences were found in bowel cleanout effectiveness, as judged by the Ottawa score (P = 0.24), completion rates (P = 0.69), colonoscopy duration (P = 0.59), need for enemas (P = 0.25), or physician's global impression (P = 0.7). Except for one case of mild dehydration in the Pico-Salax group, no clinically significant adverse events were recorded. Serum biochemistry results were similar between groups except for more hypermagnesemia associated with Pico-Salax and hypokalemia with PEG-ELS; neither was clinically significant. CONCLUSION: Children tolerate Pico-Salax better than PEG-ELS for bowel cleanout before colonoscopy. This study did not demonstrate superiority of effectiveness or safety for either regimen.

Increasing incidence of paediatric inflammatory bowel disease in Ontario, Canada: evidence from health administrative data.

OBJECTIVE: Health administrative databases can be used to track chronic diseases. The aim of this study was to validate a case ascertainment definition of paediatric-onset inflammatory bowel disease (IBD) using administrative data and describe its epidemiology in Ontario, Canada. METHODS: A population-based clinical database of patients with IBD aged <15 years was used to define cases, and patient information was linked to health administrative data to compare the accuracy of various patterns of healthcare use. The most accurate algorithm was validated with chart data of children aged <18 years from 12 medical practices. Administrative data from the period 1991-2008 were used to describe the incidence and prevalence of IBD in Ontario children. Changes in incidence were tested using Poisson regression. RESULTS: Accurate identification of children with IBD required four physician contacts or two hospitalisations (with International Classification of Disease (ICD) codes for IBD) within 3 years if they underwent colonoscopy and seven contacts or three hospitalisations within 3 years in those without colonoscopy (children <12 years old, sensitivity 90.5%, specificity >99.9%; children <15 years old, sensitivity 89.6%, specificity >99.9%; children <18 years old, sensitivity 91.1%, specificity 99.5%). Age- and sex-standardised prevalence per 100 000 population of paediatric IBD has increased from 42.1 (in 1994) to 56.3 (in 2005). Incidence per 100 000 has increased from 9.5 (in 1994) to 11.4 (in 2005). Statistically significant increases in incidence were noted in 0-4 year olds (5.0%/year, p = 0.03) and 5-9 year olds (7.6%/year, p<0.0001), but not in 10-14 or 15-17 year olds. CONCLUSION: Ontario has one of the highest rates of childhood-onset IBD in the world, and there is an accelerated increase in incidence in younger children.

Traditional corticosteroids for induction of remission in Crohn's disease.

BACKGROUND: Historically, corticosteroids have been the most commonly used class of medication for induction of remission in Crohn's disease (CD). Corticosteroids down regulate production of inflammatory cytokines and interfere with NF-kappaB production, thereby blunting inflammatory response. OBJECTIVES: The primary objective was to systematically review the efficacy and safety of traditional corticosteroids (given orally or intravenously) for induction of remission in CD. SEARCH STRATEGY: The following electronic databases were searched: MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials, the Cochrane Inflammatory Bowel Disease and Functional Bowel Disorders (IBD/FBD) Group Specialized Trial Register, and ClinicalTrials.gov. No language restrictions were applied. Reference lists of trials and review articles, as well as recent proceedings from major gastroenterology meetings were manually searched. SELECTION CRITERIA: Randomized, controlled clinical trials of traditional, systemic corticosteroids for the induction of remission of active CD were included in this review. Control groups included patients receiving either placebo or 5-aminosalicylates (5-ASA). The study population included patients of any age with active CD (as defined by the study authors or validated clinical activity indices), receiving any formulation of systemically available corticosteroid by any oral or parenteral methods of delivery. The primary outcome was induction of remission of CD. Secondary outcomes included clinical response, change in mean CDAI, adverse events and the proportion of patients withdrawing due to adverse events. DATA COLLECTION AND ANALYSIS: Two independent investigators reviewed studies for eligibility, extracted the data and assessed study quality using Jadad's criteria. A random or fixed effects model was chosen based on an assessment of heterogeneity, and studies were weighted using the DerSimonian & Laird or the Mantel-Haenszel method accordingly. Meta-analysis was performed using RevMan 4.2.10 software. MAIN RESULTS: Two studies compared corticosteroids to placebo and six studies compared corticosteroids to 5-ASA. Corticosteroids were found to be significantly more effective than placebo at inducing remission in CD (RR 1.99; 95% CI 1.51 to 2.64; P < 0.00001). Corticosteroids were found to be more effective than 5-ASA at inducing remission in studies with long follow-up duration (i.e. > 15 weeks; RR 1.65; 95% CI 1.33 to 2.03; P < 0.00001). Corticosteroids induced adverse events in a higher proportion of patients than placebo (RR 4.89; 95% CI 1.98 to 12.07; P = 0.0006), or low-dose 5-ASA (RR 2.38; 95% CI 1.34 to 4.25; P = 0.003). No difference existed in the proportion of patients experiencing adverse events when steroids were compared to high-dose 5-ASA. Steroids did not induce more study withdrawals due to adverse events than either placebo or 5-ASA. AUTHORS' CONCLUSIONS: Corticosteroids are effective for induction of remission in patients with CD, particularly when used for more than 15 weeks. Although corticosteroids cause more adverse events than either placebo or low-dose 5-ASA, these adverse events did not lead to increased study withdrawal in the included studies. Further information is required to determine the optimal duration of treatment and tapering protocol to maximize the efficacy of treatment with corticosteroids. Additionally, further study is required to determine whether corticosteroids are more effective in patients with certain phenotypes or when administered intravenously.

Severe paediatric ulcerative colitis: incidence, outcomes and optimal timing for second-line therapy.

BACKGROUND: Despite the predominance of extensive disease in children with ulcerative colitis, data concerning severe paediatric ulcerative colitis are sparse. We reviewed rates and predictors of response to intravenous-corticosteroid therapy in a single-centre cohort with long-term follow-up. METHODS: 99 children (49% males; age 2-17 years) were hospitalised (1991-2000) for treatment of severe ulcerative colitis (90% extensive; 49% new onset ulcerative colitis). Clinical, laboratory and radiographic data were reviewed. A population-based subset was used to assess incidence. Predictors of corticosteroid response were analysed using univariate and multivariate analyses at days 3 and 5 of therapy. Colectomy rates were calculated using Kaplan-Meier survival analyses. RESULTS: 28% (95% CI, 23 to 34%) of children with ulcerative colitis resident in the Greater Toronto Area required admission for intravenous corticosteroid therapy, of whom 53 (53%; 95% CI, 44 to 63%) responded. Several predictors were associated with corticosteroid failure, but in multivariable modelling only C-reactive protein [OR = 3.5 (1.4 to 8.4)] and number of nocturnal stools [OR = 3.2 (1.6 to 6.6)] remained significant at both days 3 and 5. The Pediatric Ulcerative Colitis Activity Index (PUCAI), Travis and Lindgren's indices strongly predicted non-response. Radiographically, the upper range of colonic luminal width was 40 mm in children younger than 11 years versus 60 mm in older patients. Cumulative colectomy rates at discharge, 1 year and 6 years were 42%, 58% and 61%, respectively. CONCLUSIONS: Children with ulcerative colitis commonly experience at least one severe exacerbation. Response to intravenous corticosteroids is poor. The PUCAI, determined at day 3 (>45 points) should be used to screen for patients likely to fail corticosteroids and at day 5 (>70 points) to dictate the introduction of second-line therapies.