Phenotypic and Functional Changes in Peripheral Blood Natural Killer Cells in Crohn Disease Patients.

We investigated activation status, cytotoxic potential, and gut homing ability of the peripheral blood Natural Killer (NK) cells in Crohn disease (CD) patients. For this purpose, we compared the expression of different activating and inhibitory receptors (KIR and non-KIR) and integrins on NK cells as well as their recent degranulation history between the patients and age-matched healthy controls. The study was conducted using freshly obtained peripheral blood samples from the study participants. Multiple color flow cytometry was used for these determinations. Our results show that NK cells from treatment-naïve CD patients expressed higher levels of activating KIR as well as other non-KIR activating receptors vis-à-vis healthy controls. They also showed increased frequencies of the cells expressing these receptors. The expression of several KIR and non-KIR inhibitory receptors tended to decrease compared with the cells from healthy donors. NK cells from the patients also expressed increased levels of different gut-homing integrin molecules and showed a history of increased recent degranulation events both constitutively and in response to their in vitro stimulation. Furthermore, treatment of the patients tended to reverse these NK cell changes. Our results demonstrate unequivocally, for the first time, that peripheral blood NK cells in treatment-naïve CD patients are more activated and are more poised to migrate to the gut compared to their counterpart cells from healthy individuals. Moreover, they show that treatment of the patients tends to normalize their NK cells. The results suggest that NK cells are very likely to play a role in the immunopathogenesis of Crohn disease.

Differential synthesis and release of IL-18 and IL-18 Binding Protein from human platelets and their implications for HIV infection.

IL-18 is a pro-inflammatory cytokine belonging to the IL-1 family and is produced in the body from macrophages, epithelial and dendritic cells, keratinocytes, adrenal cortex etc. The cytokine is produced as an inactive precursor that is cleaved inside cells into its mature form by activated caspase 1, which exists as an inactive precursor in human cells and requires assembly of an inflammasomes for its activation. We show here for the first time that human platelets contain transcripts for the IL-18 gene. They synthesize the cytokine de novo, process and release it upon activation. The activation also results in the assembly of an inflammasome and activation of caspase-1. Platelets also contain the IL-18 antagonist, the IL-18-Binding Protein (IL-18BP); however, it is not synthesized in them de novo, is present in pre-made form and is released irrespective of platelet activation. IL-18 and IL-18BP co-localize to α granules inside platelets and are secreted out with different kinetics. Platelet activation contributes to plasma concentrations in healthy individuals, as their plasma samples contain abundant IL-18, while their platelet-poor plasma samples contain very little amounts of the cytokine. The plasma and PPP samples from these donors, however, contain comparable amounts of IL-18BP. Unlike healthy individuals, the platelet-poor plasma from HIV-infected individuals contains significant amounts of IL-18. Our findings have important implications for viral infections and other human diseases that are accompanied by platelet activation.

A potentially protective role of IL-18 Binding Protein in HIV-infected Long-Term Non-Progressors.

An imbalance between IL-18 and its antagonist, IL-18 Binding Protein, occurs in the circulation of HIV-infected individuals. We show here for the first time that HIV-infected Long Term Non-Progressors (LTNPs) do not develop this imbalance, and maintain normal levels of IL-18BP in the circulation. Their circulating levels of the antagonist correlate negatively with viral loads and show a positive trend with CD4+ T cells counts. The maintenance of normal production of IL-18BP may contribute, at least in part, to the ability of LTNPs to delay AIDS progression.

Cardiometabolic risk factors and lactoferrin: polymorphisms and plasma levels in French-Canadian children.

BackgroundLactoferrin (LTF) could play a beneficial role in insulin resistance and diabetes, but the association of its gene variants with cardio-metabolic disorders in children has not been investigated. This study aimed to examine the relationship between LTF variants, plasma LTF concentrations, and cardio-metabolic risk factors in French-Canadian children.MethodsThe study cohort comprises 1,749 French Canadians aged 9, 13, and 16 years. The association of 13 LTF polymorphisms, metabolic parameters, and plasma LTF levels was tested in this cross-sectional, province-wide school-based survey.ResultsNone of the genetic association remained significant after correction for multiple testing and LTF SNPs were not associated with LTF levels. Plasma LTF was positively correlated with body mass index (r2=0.2245, P=0.0011) and weight (r2=0.2515, P=0.0008). After segregating according to high-density lipoprotein cholesterol (HDL-C), the association remained only in subjects exhibiting low HDL-C (r2=0.3868, P=0.0002 for body mass index and r2=0.3665, P=0.0004 for weight). In girls, plasma LTF was positively correlated with total cholesterol (r2=0.2231, P=0.0378), LDL cholesterol (r2=0.2409, P=0.0246), and apolipoprotein B (r2=0.2478, P=0.0207).ConclusionsWe found no association between LTF gene variants and metabolic parameters following correction for multiple testing. HDL-C and gender-specific positive associations were evidenced between plasma LTF, anthropometric profile, and lipid levels.

Parental occupations and risk for Crohn's disease in children.

BACKGROUND AND OBJECTIVES: Lacunae exist on the identity of specific environmental risk factors that associate with Crohn's disease (CD). We hypothesized that indirect exposures acquired via the parents' occupation may confer susceptibility. METHODS: A case-control study based on children diagnosed with CD (prior to age 20) at a tertiary care gastroenterology clinic in Montreal, Canada was carried out. Population- and hospital-based controls without IBD were selected. Information on occupations held by the parents was acquired from interview. Jobs were coded using the Canadian National Occupational Classification for Statistics. Associations were examined using logistic regression accounting for potential confounders. Odds ratios (OR) and corresponding 95% confidence intervals (CI) were estimated. RESULTS: A total of 466 cases and 335 controls were studied. The mean (±SD) age of the cases (12.4 ± 3.2) was slightly higher than controls (10.5 ± 4.9). Gender and ethnicity were equally distributed between the groups. Logistic regression analysis suggested that children whose fathers worked as retail salespersons/sales clerks [odds ratio (OR) 3.6, 95% confidence interval (CI) 1.2-11.1], and whose mothers worked as administrative secretaries (OR 3.2, 95% CI 1.6-6.4), were more likely to be at risk for CD. Mothers who worked as either early childhood educators (OR 2.3, 95% CI 0.85-6.2) or as clerks (OR 2.8, 95% CI 0.8-9.9) also appeared to confer risks, but these associations were statistically not significant. CONCLUSION: Parental occupations related to 'social mixing' that can potentially enhance exposure to infectious agents, appear to confer higher risk for CD in children.

Imbalanced production of IL-18 and its antagonist in human diseases, and its implications for HIV-1 infection.

IL-18 is a pleiotropic and multifunctional cytokine that belongs to the IL-1 family. It is produced as a biologically inactive precursor, which is cleaved into its active mature form mainly by caspase-1. The caspase becomes active from its inactive precursor (procaspase-1) upon assembly of an inflammasome. Because of IL-18's potential pro-inflammatory and tissue destructive effects, its biological activities are tightly controlled in the body by its naturally occurring antagonist called IL-18BP. The antagonist is produced in the body both constitutively and in response to an increased production of IL-18 as a negative feedback mechanism. Under physiological conditions, most of IL-18 in the circulation is bound with IL-18BP and is inactive. However, an imbalance in the production of IL-18 and its antagonist (an increase in the production of IL-18 with a decrease, no increase or an insufficient increase in the production of IL-18BP) has been described in many chronic inflammatory diseases in humans. The imbalance results in an increase in the concentrations of free IL-18 (unbound with its antagonist) resulting in increased biological activities of the cytokine that contribute towards pathogenesis of the disease. In this article, we provide an overview of the current biology of IL-18 and its antagonist, discuss how the imbalance occurs in HIV infections and how it contributes towards development of AIDS and other non-AIDS-associated clinical conditions occurring in HIV-infected individuals undergoing combination anti-retroviral therapy (cART). Finally, we discuss challenges facing immunotherapeutic strategies aimed at restoring balance between IL-18 and its antagonist in these patients.

Apple peel polyphenols: a key player in the prevention and treatment of experimental inflammatory bowel disease.

Diets rich in fruits and vegetables may reduce oxidative stress (OxS) and inflammation via several mechanisms. These beneficial effects may be due to their high polyphenol content. The aims of the present study are to evaluate the preventive and therapeutic aspects of polyphenols in dried apple peel powder (DAPP) on intestinal inflammation while elucidating the underlying mechanisms and clinical benefits. Induction of intestinal inflammation in mice was performed by oral administration of the inflammatory agent dextran sulfate sodium (DSS) at 2.5% for 10 days. Physiological and supraphysiological doses of DAPP (200 and 400 mg/kg/day respectively) were administered by gavage for 10 days pre- and post-DSS treatment. DSS-mediated inflammation caused weight loss, shortening of the colon, dystrophic detachment of the epithelium, and infiltration of mono- and poly-morphonuclear cells in the colon. DSS induced an increase in lipid peroxidation, a down-regulation of antioxidant enzymes, an augmented expression of myeloperoxidase (MPO) and cyclooxygenase-2 (COX-2), an elevated production of prostaglandin E2 (PGE2) and a shift in mucosa-associated microbial composition. However, DAPP normalized most of these abnormalities in preventive or therapeutic situations in addition to lowering inflammatory cytokines while stimulating antioxidant transcription factors and modulating other potential healing pathways. The supraphysiological dose of DAPP in therapeutic situations also improved mitochondrial dysfunction. Relative abundance of Peptostreptococcaceae and Enterobacteriaceae bacteria was slightly decreased in DAPP-treated mice. In conclusion, DAPP exhibits powerful antioxidant and anti-inflammatory action in the intestine and is associated with the regulation of cellular signalling pathways and changes in microbiota composition. Evaluation of preventive and therapeutic effects of DAPP may be clinically feasible in individuals with intestinal inflammatory bowel diseases.

Use of patency capsule in patients with established Crohn's disease.

BACKGROUND AND STUDY AIMS: Video capsule endoscopy (VCE) is invaluable in the diagnosis of small-bowel pathology. Capsule retention is a major concern in patients with Crohn's disease. The patency capsule was designed to evaluate small-bowel patency before VCE. However, the actual benefit of the patency capsule test in Crohn's disease remains unclear. The aim of this study was to evaluate the clinical impact of patency capsule use on the risk of video capsule retention in patients with established Crohn's disease. PATIENTS AND METHODS: This was a retrospective, multicenter study of patients with established Crohn's disease who underwent VCE for clinical need. The utilization strategy for the patency capsule was classified as selective (only in patients with obstructive symptoms, history of intestinal obstruction or surgery, or per treating physician's request) or nonselective (all patients with Crohn's disease). The main outcome was video capsule retention in the entire cohort and within each utilization strategy. RESULTS: A total of 406 patients who were referred for VCE were included in the study. VCE was performed in 132 /406 patients (32.5 %) without a prior patency capsule test. The patency capsule test was performed in 274 /406 patients (67.5 %) and was negative in 193 patients. Overall, VCE was performed in 343 patients and was retained in the small bowel in 8 (2.3 %). In this cohort, the risk of video capsule retention in the small bowel was 1.5 % without use of a prior patency capsule and 2.1 % after a negative patency test (P = 0.9). A total of 18 patients underwent VCE after a positive patency capsule test, with a retention rate of 11.1 % (P = 0.01). Patency capsule administration strategy (selective vs. nonselective) was not associated with the risk of video capsule retention. CONCLUSIONS: Capsule retention is a rare event in patients with established Crohn's disease undergoing VCE. The risk of video capsule retention was not reduced by the nonselective use of the patency capsule. Furthermore, VCE after a positive patency capsule test in patients with Crohn's disease was associated with a high risk of video capsule retention.

Interactions between the dietary polyunsaturated fatty acid ratio and genetic factors determine susceptibility to pediatric Crohn's disease.

Increased dietary ratios of ω6/ω3 polyunsaturated fatty acids have been implicated in the pathogenesis of Crohn's disease (CD), but epidemiologic data are limited. We investigated whether variants of genes that control polyunsaturated fatty acid metabolism (CYP4F3, FADS1, and FADS2), along with the dietary ratio of ω6/ω3, confers susceptibility to CD. Based on data from 182 children newly diagnosed with CD and 250 controls, we found that children who consumed a higher dietary ratio of ω6/ω3 were susceptible for CD if they were also carriers of specific variants of CYP4F3 and FADS2 genes. Our findings implicate diet-gene interactions in the pathogenesis of CD.

Novel associations between activating killer-cell immunoglobulin-like receptor genes and childhood leukemia.

Acute lymphoblastic leukemia of pre-B cells (pre-B ALL) is the most frequent form of leukemia affecting children in Western countries. Evidence is accumulating that genetic factors play an important role in conferring susceptibility/resistance to leukemia in children. In this regard, activating killer-cell immunoglobulin-like receptor (KIR) genes are of particular interest. Humans may inherit different numbers of the 6 distinct activating KIR genes. Little is known about the impact of this genetic variation on the innate susceptibility or resistance of humans to the development of B-ALL. We addressed this issue by performing a case-control study in Canadian children of white origin. Our results show that harboring activating KIR genes is associated with reduced risk for developing B-ALL in these children. Of the 6 activating KIR genes, KIR2DS2 was maximally associated with decreased risk for the disease (P = 1.14 × 10(-7)). Furthermore, our results showed that inheritance of a higher number of activating KIR genes was associated with significant reductions in risk for ALL in children. These results were also consistent across different ALL phenotypes, which included children with pre-T cell ALL. Our study provides novel insights concerning the pathogenesis of childhood leukemia in white children and has implications for the development of new immunotherapies for this cancer.

A randomized controlled trial of flunarizine as add-on therapy and effect on cognitive outcome in children with infantile spasms.

PURPOSE: Cognitive impairment is observed commonly in children with a history of infantile spasms (IS). The goal of this study was to prospectively examine the effect on cognitive outcome of a neuroprotective agent used as adjunctive therapy during treatment of the spasms. METHODS: In a randomized controlled trial, patients received a standardized therapy plus flunarizine or placebo. The standardized treatment consisted of vigabatrin as first-line therapy. Nonresponders were switched to intramuscular synthetic adrenocorticotropic hormone (sACTH depot) after 2 weeks and, if necessary, to topiramate after two additional weeks. The Vineland Adaptive Behavior Scale (VABS) and Bayley Scales of Infant Development (BSID) were used as outcome measures 24 months after the intervention. KEY FINDINGS: Sixty-eight of 101 children diagnosed over 3 years in seven centers in Canada received either adjunctive flunarizine or placebo. Sixty-five of the 68 children (96%) became spasm-free within 8 weeks and no late relapse occurred. Bayley and Vineland results were available at baseline and at 24 months in 45 children. There was no significant difference in the BSID developmental quotient between the flunarizine- and placebo-treated children at baseline (44.3 ± 35.5 vs. 30.9 ± 29.8; p = 0.18) or 24 months later (56.9 ± 33.3 vs. 46 ± 34.2; p = 0.29). However, the 10 flunarizine-treated children with no identified etiology had a better outcome than the eight controls at 24 months on both the Vineland Scale (84.1 ± 11.3 vs. 72.3 ± 9.8; p = 0.03) and the Bayley Scale (87.6 ± 14.7 vs. 69.9 ± 25.3; p = 0.07). SIGNIFICANCE: Our study failed to demonstrate a protective effect of flunarizine on cognitive outcome in a cohort of children with IS. An analysis of subgroups suggested that flunarizine may further improve cognitive outcome in children with no identified etiology.

The Canadian Triage and Acuity Scale for children: a prospective multicenter evaluation.

STUDY OBJECTIVE: The aims of the study are to measure both the interrater agreement of nurses using the Canadian Triage and Acuity Scale in children and the validity of the scale as measured by the correlation between triage level and proxy markers of severity. METHODS: This was a prospective multicenter study of the reliability and construct validity of the Canadian Triage and Acuity Scale in 9 tertiary care pediatric emergency departments (EDs) across Canada during 2009 to 2010. Participants were a sample of children initially triaged as Canadian Triage and Acuity Scale level 2 (emergency) to level 5 (nonurgent). Participants were recruited immediately after their initial triage to undergo a second triage assessment by the research nurse. Both triages were performed blinded to the other. The primary outcome measures were the interrater agreement between the 2 nurses and the association between triage level and hospitalization. Secondary outcome measures were the association between triage level and health resource use and length of stay in the ED. RESULTS: A total of 1,564 patients were approached and 1,464 consented. The overall interrater agreement was good, as demonstrated by a quadratic weighted κ score of 0.74 (95% confidence interval 0.71 to 0.76). Hospitalization proportions were 30%, 8.3%, 2.3%, and 2.2% for patients triaged at levels 2, 3, 4, and 5, respectively. There was also a strong association between triage levels and use of health care resources and length of stay. CONCLUSION: The Canadian Triage and Acuity Scale demonstrates a good interrater agreement between nurses across multiple pediatric EDs and is a valid triage tool, as demonstrated by its good association with markers of severity.

Modification in oxidative stress, inflammation, and lipoprotein assembly in response to hepatocyte nuclear factor 4alpha knockdown in intestinal epithelial cells.

Hepatocyte nuclear factor 4α (HNF4α) is a nuclear transcription factor mainly expressed in the liver, intestine, kidney, and pancreas. Many of its hepatic and pancreatic functions have been described, but limited information is available on its role in the gastrointestinal tract. The objectives of this study were to evaluate the anti-inflammatory and antioxidant functions of HNF4α as well as its implication in intestinal lipid transport and metabolism. To this end, the HNF4A gene was knocked down by transfecting Caco-2 cells with a pGFP-V-RS lentiviral vector containing an shRNA against HNF4α. Inactivation of HNF4α in Caco-2 cells resulted in the following: (a) an increase in oxidative stress as demonstrated by the levels of malondialdehyde and conjugated dienes; (b) a reduction in secondary endogenous antioxidants (catalase, glutathione peroxidase, and heme oxygenase-1); (c) a lower protein expression of nuclear factor erythroid 2-related factor that controls the antioxidant response elements-regulated antioxidant enzymes; (d) an accentuation of cellular inflammatory activation as shown by levels of nuclear factor-κB, interleukin-6, interleukin-8, and leukotriene B4; (e) a decrease in the output of high density lipoproteins and of their anti-inflammatory and anti-oxidative components apolipoproteins (apo) A-I and A-IV; (f) a diminution in cellular lipid transport revealed by a lower cellular secretion of chylomicrons and their apoB-48 moiety; and (g) alterations in the transcription factors sterol regulatory element-binding protein 2, peroxisome proliferator-activated receptor α, and liver X receptor α and ß. In conclusion, HNF4α appears to play a key role in intestinal lipid metabolism as well as intestinal anti-oxidative and anti-inflammatory defense mechanisms.

Variation in the glucocorticoid receptor gene (NR3C1) may be associated with corticosteroid dependency and resistance in children with Crohn's disease.

OBJECTIVES: In pediatric onset of Crohn's disease (CD), corticosteroid dependency (approximately 40%) and resistance (approximately 10%) are significant clinical problems. Given the known effects of the glucocorticoid receptor (GR/NR3C1) gene in corticosteroid metabolism, we investigated whether variation in the gene was associated with corticosteroid response. METHODS: A retrospective cohort study was carried out including patients with CD diagnosed before 18 years and treated with a first course of corticosteroids in two Canadian tertiary pediatric gastroenterology clinics. DNA was obtained from blood or saliva. Tagging single nucleotide polymorphisms (SNPs) and functionally important SNPs were genotyped. Allelic, genotype, and haplotype associations between the glucocorticoid receptor SNPs and response to corticosteroids were examined. RESULTS: A total of 296 corticosteroid-resistant, corticosteroids-dependent, and corticosteroid-responsive patients with CD were studied. Of the 12 SNPs examined, four markers, rs6196 [odds ratio (OR)=2.03; 95% confidence interval (CI): 1.03-4.0; P=0.042], rs7701443 (OR=3.43; 95% CI: 1.79-6.57; P=0.042), rs6190 (OR=4.84; 95% CI: 1.70-13.80; P=0.003), and rs860457 (OR=3.43; 95% CI: 1.79-6.57; P<0.001) were associated at the allelic level with corticosteroid resistance. Haplotype analysis of four associated markers revealed associations between two haplotypes and corticosteroid resistance (P values of 0.046 and 0.001). Three SNPs, rs10482682 (OR=1.43; 95% CI: 0.99-2.08; P=0.047), rs6196 (OR=0.55; 95% CI: 0.31-0.95; P=0.024), and rs2963155 (OR=0.64; 95% CI: 0.42-0.98; P=0.039), showed associations under an additive model, whereas rs4912911 (OR=0.37; 95% CI: 0.13-1.00; P=0.03) and rs2963156 (OR=0.32; 95% CI: 0.07-1.12; P=0.047) showed associations under a recessive model with corticosteroid dependence. Two five-marker haplotypes were associated with corticosteroid dependence (P values 0.002 and 0.004). CONCLUSION: Our results suggest that variations in the GR/NR3C1 gene are associated with corticosteroid resistance and dependency in pediatric-onset CD. Studies are required to replicate these findings and to identify the potentially relevant variants.

Primary Immunodeficiency in Children With Autoimmune Cytopenias: Retrospective 154-Patient Cohort.

Background: Primary immunodeficiency is common among patients with autoimmune cytopenia. Objective: The purpose of this study is to retrospectively identify key clinical features and biomarkers of primary immunodeficiency (PID) in pediatric patients with autoimmune cytopenias (AIC) so as to facilitate early diagnosis and targeted therapy. Methods: Electronic medical records at a pediatric tertiary care center were reviewed. We selected 154 patients with both AIC and PID (n=17), or AIC alone (n=137) for inclusion in two cohorts. Immunoglobulin levels, vaccine titers, lymphocyte subsets (T, B and NK cells), autoantibodies, clinical characteristics, and response to treatment were recorded. Results: Clinical features associated with AIC-PID included splenomegaly, short stature, and recurrent or chronic infections. PID patients were more likely to have autoimmune hemolytic anemia (AIHA) or Evans syndrome than AIC-only patients. The AIC-PID group was also distinguished by low T cells (CD3 and CD8), low immunoglobulins (IgG and IgA), and higher prevalence of autoantibodies to red blood cells, platelets or neutrophils. AIC diagnosis preceded PID diagnosis by 3 years on average, except among those with partial DiGeorge syndrome. AIC-PID patients were more likely to fail first-line treatment. Conclusions: AIC patients, especially those with Evans syndrome or AIHA, should be evaluated for PID. Lymphocyte subsets and immune globulins serve as a rapid screen for underlying PID. Early detection of patients with comorbid PID and AIC may improve treatment outcomes. Prospective studies are needed to confirm the diagnostic clues identified and to guide targeted therapy.

Association between genome-wide association studies reported SNPs and pediatric-onset Crohn's disease in Canadian children.

A recent pediatric-focused genome-wide association study has implicated three novel susceptibility loci for Crohn' disease (CD).We aimed to investigate whether the three recently reported and other previously reported genes/loci were also associated with CD in Canadian children. A case-control design was implemented at three pediatric gastroenterology clinics in Canada. Children <19 years of age with a confirmed diagnosis of CD were recruited along with controls. Single nucleotide polymorphisms (SNPs) in 19 reported genes/loci were genotyped. Associations between individual SNPs and CD were examined. A total of 563 cases and 553 controls were studied. The mean (+/-SD) age of the cases was 12.3 (+/-3.2) years. Most cases were male (56.0%), had ileo-colonic disease (L3 +/- L4, 48.8%) and inflammatory behavior (B1 +/- p, 87.9%) at diagnosis. Allelic association analysis (two-tailed) showed that 8 of the 19 targeted SNPs were significantly associated with overall susceptibility for CD. Associations with one additional SNP was borderline non-significant. Significantly associated SNPs included SNPs rs1250550 (p = 0.026) and rs8049439 (p = 0.04), recently reported to be specifically associated with pediatric-onset CD.Based on the results, we confirmed associations between two of the three novel pediatric-CD loci and other regions reported for associations with either pediatric and/or adult-onset CD.

Examining the relative validity of an adult food frequency questionnaire in children and adolescents.

BACKGROUND AND OBJECTIVE: Dietary factors have been implicated in the pathogenesis of inflammatory bowel diseases (IBD). The aim of the study was to assess the accuracy of a food frequency questionnaire (FFQ) developed in French and English for adults 18 years and older, among subjects ages 7 to 18 years participating in a prospective cohort study. PATIENTS AND METHODS: Healthy children and adolescents ages 7 to 18 years were recruited from outpatient orthopedic clinics in a Montréal pediatric hospital. Of the 131 recruits, 65 (86% Francophone) provided a complete 78-item semiquantitative FFQ and 3-day nonconsecutive food records (3D-FR). Parents of young children completed both instruments, whereas older children and adolescents completed them on their own. The FFQ were analyzed using Microsoft Access software for customized data entry and the 3D-FR were analyzed using CANDAT software, both based on the 2007b Canadian Nutrient File. RESULTS: The FFQ overestimated intakes relative to the 3D-FR by around 15%. Spearman rank correlation coefficients between test and reference methods were positive, largely ranged from 0.22 (vitamin C) to 0.57 (saturated fat), and were generally statistically significant (0.05< P < 0.0001). Stronger associations between test and reference methods were found for adolescents (13-18 years) and for girls. Some 77% of participants were jointly classified into the same half of the distribution, with 39% exact agreement and only 6% frank misclassification. CONCLUSIONS: The FFQ can be confidently used to rank young subjects on a range of nutrient intakes with the potential to provide useful information on dietary risk factors in the etiology of inflammatory bowel disease. Accuracy could be enhanced by improving completion quality of FFQs, notably by young adolescent boys.

CpG Methylation in TGFß1 and IL-6 Genes as Surrogate Biomarkers for Diagnosis of IBD in Children.

BACKGROUND: Diagnostic markers for distinguishing between Crohn disease (CD) and ulcerative colitis (UC) remain elusive. We studied whether methylation marks across the promoters of the transforming growth factor beta 1 (TGFß1) and interleukin-6 genes have diagnostic utility. METHODS: A case-control study was carried out. Cases were treatment-naïve, diagnosed before age 20, and recruited from 3 pediatric gastroenterology clinics across Canada. Control patients did not have inflammatory bowel disease and were recruited from orthopedic clinics within the same hospitals as the gastroenterology clinics. Patient DNA from peripheral blood was processed to identify methylation sites (CpG) across the promoter regions of the TGFß1 and interleukin-6 genes. After initial nonparametric univariate analyses, multivariate logistic regression models were fit. Models with the best fit (Akaike information criteria) and strongest discriminatory capabilities (area under the curve [AUC]) were identified, and P values were adjusted for multiple comparisons using the false discovery rate method. RESULTS: A total of 67 CD, 31 UC, and 43 control patients were included. The age distribution of the 3 groups was similar. Most CD patients had ileocolonic disease (44.8%) and inflammatory disease (88.1%). Most UC patients had extensive (71%) and moderate disease (51.6%). Logistic regression analysis revealed the following: 14 TGFß1 CpG sites discriminated between CD and control patients (AUC = 0.94), 9 TGFß1 CpG sites discriminated between UC and control patients (AUC = 0.99), 3 TGFß1 CpG sites discriminated between CD and UC (AUC = 0.81), and 6 TGFß1 CpG sites distinguished colonic CD from UC (AUC = 0.91). CONCLUSIONS: We found that CpG methylation in the promoter of the TGFß1 gene has high discriminative power for identifying CD and UC and could serve as an important diagnostic marker.

Investigation of reported associations between the 20q13 and 21q22 loci and pediatric-onset Crohn's disease in Canadian children.

OBJECTIVES: A recent pediatric-focused genome-wide association study has reported novel associations of the 20q13 and 21q22 loci with inflammatory bowel disease (IBD). We aimed to investigate these associations with Crohn's disease (CD) in Canadian children. METHODS: A combined case-control and case-parent design was implemented at three pediatric gastroenterology clinics in Canada. Children less than 20 years of age with a confirmed diagnosis of CD were recruited along with controls. For a subset of the patients, biological parents were also recruited. Three single-nucleotide polymorphisms (SNPs) at the 20q13 locus and 1 SNP at the 21q22 locus were genotyped. Associations between individual SNPs and haplotypes were examined. RESULTS: A total of 410 cases, 415 controls, and 302 parents were studied. The mean (+/-s.d.) age for the cases was 12.3 (+/-3.2) years. Most cases were men (56.1%) who had ileocolonic disease (L3+/-L4, 52.2%) and inflammatory behavior (B1+/-B4, 87.0%) at diagnosis. Single SNP analysis showed that all 3 SNPs at the 20q13 locus were significantly associated with CD (rs2297441, P=2.24x10(-4); rs2315008, P=4.77x10(-4); rs4809330, P=6.08x10(-3)). Haplotype analysis suggested that the association signal at 20q13 resided on a common haplotype comprising the minor allele of rs2297441 (P=2.8x10(-5)). SNP rs2836878 at the 21q22 locus showed a trend for association with CD that was statistically not significant (P=0.06). CONCLUSIONS: Our results support an association between the 20q13 locus and CD in Canadian children. Positional cloning studies are required to further dissect the potential causative genes in the region.

Cancer risk in children and young adults born preterm: A systematic review and meta-analysis.

INTRODUCTION: Risk of developing a malignancy when born premature is unknown. We hypothesised that risk of certain cancers might be increased in youth born preterm versus term. We therefore performed a systematic review and meta-analysis to evaluate the incidence of malignancy in the context of preterm birth, according to various cancer types. METHODS: The study was designed per MOOSE and PRISMA guidelines. Articles were identified through November 2015. Observational studies exploring the association between childhood malignancy and birth characteristics were included. Of the 1658 records identified, 109 full text articles were evaluated for eligibility. Random effects meta-analyses were conducted on 10/26 studies retained; 95% confidence intervals were computed and adjusted following sensitivity analysis. Publication bias was evaluated using funnel plots, Begg's and Egger's tests. RESULTS: No differences in risk of primary central nervous system tumor [OR 1.05; 95% CI 0.93-1.17, 5 studies, 580 cases] and neuroblastoma [OR 1.09; 95% CI 0.90-1.32, 5 studies, 211 cases] were observed in individuals born <37 versus ≥37 weeks' gestation. Preterm birth was consistently associated with hepatoblastoma [ORs 3.12 (95% CI 2.32-4.20), 1.52 (95% CI 1.1-2.1), 1.82 (95% CI 1.01-3.26), and 2.65 (95% CI 1.98-3.55)], but not leukemia, astrocytoma, ependymoma, medulloblastoma, lymphoma, nephroblastoma, rhabdomyosarcoma, retinoblastoma or thyroid cancer. CONCLUSIONS: Children born premature may be at increased risk for hepatoblastoma but there is no strong evidence of an increased risk of primary central nervous system tumours or neuroblastoma. There is insufficient evidence to conclude whether prematurity modulates the risk of other childhood cancers.