A164 IDENTIFYING THE MOST IMPORTANT PREDICTORS TO CORRELATE SERUM METABOLITES WITH MRE CHANGES IN PATIENTS WITH PEDIATRIC CROHN DISEASE

Background

Endoscopy has been the gold standard for assessing activity in Pediatric Crohn disease (pCD); however, it is limited by its invasiveness and partial assessment of small intestine and transmural inflammation. To that end, the Pediatric Inflammatory Crohn's MRE Index (PICMI) is a valid, reliable, non-invasive, and responsive index that includes transmural inflammation when assessing disease activity.

The pathogenesis of pCD remains poorly understood, but evidence suggests that endogenous metabolites produced in the intestinal tract might mediate pathogenesis. Despite the important applicability of metabolomics in increasing the understanding of pCD, there has been limited research on this topic.

Purpose

Serum metabolomic profiles are linked to disease activity in pediatric Crohn disease.

Method

ImageKids is a multicenter, prospective, observational cohort study, designed to develop PICMI for pCD. The study was conducted over 18 months with paired serum specimens collected at study initiation and completion for 56 pCD patients. Due to the long time between the visits and the fact that during the study variables that highly affect serum metabolites were not controlled, we considered each patient visit as an individual measure point. Metabolites were identified using a quantitative metabolomics approach through The Metabolomics Innovation Centre (TMIC; University of Alberta). Disease activity was determined by the cutoff values in the total PICMI score of each patient.

The most relevant serum metabolites were identified by medium-level and high-level variable selection analysis. Pearson correlation and hypothesis testing were used to select important metabolites. Decision trees, regularization techniques, and support vector machines were used to assess explicit importance of metabolites in disease activity.

Result(s)

This work provides a strategy to reduce a dimensional dataset from a metabolomic experiment. By medium-level selection analysis we were able to identify 117 statistical important metabolites for disease activity. The high-level selection analysis allowed to indicate the importance of the top 10 metabolites trough disease activity (defined by PICMI index). Results, also show that the evaluation of importance of metabolites through multivariate statistical models is dependent of the intrinsic variable selection model.

Figure 1 reveals that Tryptophan ranked highest in the feature importance scoring. Histidine, Methylhistidine, Citric acid, Isoleucine, and Decanoylcarnitine also correlated well with disease severity.

Image

Conclusion(s)

This work uses a unique approach of multivariate statistical analyses, to identify metabolites associated with pCD disease activity. Tryptophan has been previously identified as significantly altered in the blood of IBD patients compared to controls. Histidine is known to be involved in the mediation of oxidative stress, potentially influencing intestinal inflammation. These metabolites could serve as biomarkers and help define pCD pathogenesis.

Disclosure of Interest

None Declared

A176 UTILITY OF MACHINE LEARNING FOR SERUM METABOLOMIC DATA ANALYSIS IN PEDIATRIC CROHN DISEASE

Background

The pathogenesis of pCD remains poorly understood, but evidence suggests roles for genetics, environment, immune response, and gut microbes. Microbial changes can contribute to chronic inflammation and correlate with disease severity. Metabolomics reflects interactions between host immune and gut microbial function by quantifying compounds in biological samples. Therefore, metabolomics provides a unique opportunity to gain insight into pCD pathogenesis.

Aims

To correlate disease severity, metabolites, and clinical data by applying machine learning algorithms in pediatric Crohn Disease (pCD).

Methods

ImageKids is a multicenter, prospective, cohort observational study, conducted to develop magnetic resonance enterography (MRE) indices for pCD. Paired serum specimens were collected at study initiation (Visit One; V1) and completion (Visit Four; V4; 18 months) for 120 pCD patients. Serum from patients with representative clinical scenarios and paired samples was analyzed at The Metabolomics Innovation Centre (TMIC; University of Alberta) and 131 metabolites were identified. Metabolites were analyzed via Unsupervised (U.ML) and Supervised (S.ML) Machine Learning algorithms based on Scikit-learn library in Python. Principal Component Analysis (PCA) was used to identify the variation pattern of the patients’ metabolome. Classifiers and regression algorithms were trained to assess correlation with disease activity.

Results

Results were available for the 56 paired samples. U.ML demonstrated distinct metabolome profiles with V1 clustering mainly attributed to aspartic acid, glutamic acid, and kynurenine. V4 clustering was mainly attributed to spermidine, spermine, total dimethylarginine. Furthermore, demographics was found as an important environmental factor driving distinct patterns of the metabolomics profile.

After training different classifiers and regressors with S. ML algorithms, metabolome data were correlated with disease severity (defined by C-reactive protein and fecal calprotectin). Isoleucine, p-hydroxyhippuric acid, and putrescine were the top three compounds associated with disease severity. The accuracy of our classification models was of 80% and the coefficient of determination of our regression models was 0.5

Conclusions

Metabolomic analysis can provide insight into disease pathogenesis and help predict disease severity among pCD patients. The correlation between metabolomics and disease severity might allow a better understanding of changes in host-microbe interactions and introduce new diagnostic or therapeutic options.

Funding Agencies

CIHR

Malignancy and mortality in paediatric-onset inflammatory bowel disease: a 3-year prospective, multinational study from the paediatric IBD Porto group of ESPGHAN

BACKGROUND

Risk benefit strategies in managing inflammatory bowel diseases (IBD) are dependent upon understanding the risks of uncontrolled inflammation vs those of treatments. Malignancy and mortality in IBD have been associated with disease-related inflammation and immune suppression, but data are limited due to their rare occurrence.

AIM

To identify and describe the most common causes of mortality, types of cancer and previous or current therapy among children and young adults with paediatric-onset IBD.

METHODS

Information on paediatric-onset IBD patients diagnosed with malignancy or mortality was prospectively collected via a survey in 25 countries over a 42-month period. Patients were included if death or malignancy occurred after IBD diagnosis but before the age of 26 years.

RESULTS

In total, 60 patients were identified including 43 malignancies and 26 fatal cases (9 due to cancer). Main causes of fatality were malignancies (n = 9), IBD or IBD-therapy related nonmalignant causes (n = 10; including 5 infections), and suicides (n = 3). Three cases, all fatal, of hepatosplenic T-cell lymphoma were identified, all were biologic-naïve but thiopurine-exposed. No other haematological malignancies were fatal. The 6 other fatal cancer cases included 3 colorectal adenocarcinomas and 3 cholangiocarcinomas (CCAs). Primary sclerosing cholangitis (PSC) was present in 5 (56%) fatal cancers (1 colorectal carcinoma, 3 CCAs and 1 hepatosplenic T-cell lymphoma).

CONCLUSIONS

We report the largest number of paediatric-onset IBD patients with cancer and/or fatal outcomes to date. Malignancies followed by infections were the major causes of mortality. We identified PSC as a significant risk factor for cancer-associated mortality. Disease-related adenocarcinomas were a commoner cause of death than lymphomas.

Early life travelling does not increase risk of atopic outcomes until 15 years: results from GINIplus and LISAplus

BACKGROUND

Westernized lifestyle has been blamed for allergy epidemics. One of its characteristics is increased distances and frequency of travelling from early life onwards. Early life travelling to places which substantially differ from home environment in terms of climate, vegetation and food could increase the exposure to further unknown allergens and hence promote the development of allergies, but no epidemiological study has investigated this speculation.

METHODS

Detailed data on travelling during the first 2 years of life as well as a range of atopic outcomes along with potential confounders up to age 15 years were collected prospectively within two large population-based multicentre German birth cohorts - GINIplus and LISAplus. Farthest travelling destination (within Germany; middle/northern/eastern Europe; southern Europe; outside Europe), total number of trips and their combination were considered as exposures. Six atopic outcomes were used: (1) doctor-diagnosed asthma, (2) doctor-diagnosed allergic rhinitis, (3) nose and eye symptoms, (4) sensitization to food allergens, (5) sensitization to indoor and (6) outdoor inhalant allergens. Longitudinal associations between each exposure and health outcome pair were analysed using generalized estimation equations (GEEs).

RESULTS

The results of our longitudinal analyses of 5674 subjects do not support the research hypothesis that travelling abroad to different regions in Europe or beyond Europe and frequency of travelling increase prevalence of doctor-diagnosed asthma and allergic rhinitis, nose and eye symptoms and allergic sensitization up to 15 years of age. Furthermore, there was no indication of age-varying effects.

CONCLUSIONS

Early life travelling does not seem to increase risk of atopic outcomes. Nevertheless, as we could not account for the type of visited environment or length of stay, these first findings should be interpreted with caution.

Paving the way of systems biology and precision medicine in allergic diseases: the MeDALL success story: Mechanisms of the Development of ALLergy; EU FP7-CP-IP; Project No: 261357; 2010-2015

MeDALL (Mechanisms of the Development of ALLergy; EU FP7-CP-IP; Project No: 261357; 2010-2015) has proposed an innovative approach to develop early indicators for the prediction, diagnosis, prevention and targets for therapy. MeDALL has linked epidemiological, clinical and basic research using a stepwise, large-scale and integrative approach: MeDALL data of precisely phenotyped children followed in 14 birth cohorts spread across Europe were combined with systems biology (omics, IgE measurement using microarrays) and environmental data. Multimorbidity in the same child is more common than expected by chance alone, suggesting that these diseases share causal mechanisms irrespective of IgE sensitization. IgE sensitization should be considered differently in monosensitized and polysensitized individuals. Allergic multimorbidities and IgE polysensitization are often associated with the persistence or severity of allergic diseases. Environmental exposures are relevant for the development of allergy-related diseases. To complement the population-based studies in children, MeDALL included mechanistic experimental animal studies and in vitro studies in humans. The integration of multimorbidities and polysensitization has resulted in a new classification framework of allergic diseases that could help to improve the understanding of genetic and epigenetic mechanisms of allergy as well as to better manage allergic diseases. Ethics and gender were considered. MeDALL has deployed translational activities within the EU agenda.

[S2k-guideline Helicobacter pylori and gastroduodenal ulcer disease]

In the line "bismuth-containing quadruple therapy" of Table 7 (p 342), in the column "dosage" incorrectly at the three antibiotics respectively 1-1-1-1. The correct is: 3-3-3-3.

Allergic manifestation 15 years after early intervention with hydrolyzed formulas--the GINI Study

Background

Data on the long‐term impact of hydrolyzed formulas on allergies are scarce.

Objective

To assess the association between early intervention with hydrolyzed formulas in high‐risk children and allergic outcomes in adolescence.

Methods

GINI trial participants (n = 2252) received one of four formulas in the first four months of life as breastmilk substitute if necessary: partial or extensive whey hydrolyzate (pHF‐W, eHF‐W), extensive casein hydrolyzate (eHF‐C) or standard cow′s milk formula (CMF) as reference. Associations between these formulas and the cumulative incidence and prevalence of parent‐reported physician‐diagnosed asthma, allergic rhinitis (AR) and eczema, as well as spirometric indices and sensitization, were examined using generalized linear models.

Results

Between 11 and 15 years, the prevalence of asthma was reduced in the eHF‐C group compared to CMF (odds ratio (OR) 0.49, 95% confidence interval (CI) 0.26–0.89), which is consistent with the spirometric results. The cumulative incidence of AR was lower in eHF‐C (risk ratio (RR) 0.77, 95% CI 0.59–0.99]) and the AR prevalence in pHF‐W (OR 0.67, 95% CI 0.47–0.95) and eHF‐C (OR 0.59, 95% CI 0.41–0.84). The cumulative incidence of eczema was reduced in pHF‐W (RR 0.75, 95% CI 0.59–0.96) and eHF‐C (RR 0.60, 95% CI 0.46–0.77), as was the eczema prevalence between 11 and 15 years in eHF‐C (OR 0.42, 95% CI 0.23–0.79). No significant effects were found in the eHF‐W group on any manifestation,nor was there an effect on sensitization with any formula.

Conclusion

In high‐risk children, early intervention using different hydrolyzed formulas has variable preventative effects on asthma, allergic rhinitis and eczema up to adolescence.

Associations between serum 25-hydroxyvitamin D and bone turnover markers in a population based sample of German children

Severe vitamin D deficiency is known to cause rickets, however epidemiological studies and RCTs did not reveal conclusive associations for other parameters of bone health. In our study, we aimed to investigate the association between serum levels of 25(OH) vitamin D and bone turnover markers in a population-based sample of children. 25(OH)D, calcium (Ca), osteocalcin (OC), and β-Crosslaps (β-CTx) were measured in 2798 ten-year-old children from the German birth cohorts GINIplus and LISAplus. Linear regression was used to determine the association between bone turnover markers and 25(OH)D levels. 25(OH)D, OC, and β-CTx showed a clear seasonal variation. A 10 nmol/l increase in 25(OH)D was significantly associated with a 10.5 ng/l decrease (p < 0.001) in β-CTx after adjustment for design, sex, fasting status, time of blood drawn, BMI, growth rate, and detectable testosterone/estradiol. For OC alone no significant association with 25(OH)D was observed, whereas the β-CTx-to-OC ratio was inversely associated with 25(OH)D (−1.7% change, p < 0.001). When stratifying the analyses by serum calcium levels, associations were stronger in children with Ca levels below the median. This study in school-aged children showed a seasonal variation of 25(OH)D and the bone turnover markers OC and β-CTx. Furthermore a negative association between 25(OH)D and the bone resorption marker β-CTx was observed.

Phenotyping asthma, rhinitis and eczema in MeDALL population-based birth cohorts: an allergic comorbidity cluster

BACKGROUND

Asthma, rhinitis and eczema often co-occur in children, but their interrelationships at the population level have been poorly addressed. We assessed co-occurrence of childhood asthma, rhinitis and eczema using unsupervised statistical techniques.

METHODS

We included 17 209 children at 4 years and 14 585 at 8 years from seven European population-based birth cohorts (MeDALL project). At each age period, children were grouped, using partitioning cluster analysis, according to the distribution of 23 variables covering symptoms 'ever' and 'in the last 12 months', doctor diagnosis, age of onset and treatments of asthma, rhinitis and eczema; immunoglobulin E sensitization; weight; and height. We tested the sensitivity of our estimates to subject and variable selections, and to different statistical approaches, including latent class analysis and self-organizing maps.

RESULTS

Two groups were identified as the optimal way to cluster the data at both age periods and in all sensitivity analyses. The first (reference) group at 4 and 8 years (including 70% and 79% of children, respectively) was characterized by a low prevalence of symptoms and sensitization, whereas the second (symptomatic) group exhibited more frequent symptoms and sensitization. Ninety-nine percentage of children with comorbidities (co-occurrence of asthma, rhinitis and/or eczema) were included in the symptomatic group at both ages. The children's characteristics in both groups were consistent in all sensitivity analyses.

CONCLUSION

At 4 and 8 years, at the population level, asthma, rhinitis and eczema can be classified together as an allergic comorbidity cluster. Future research including time-repeated assessments and biological data will help understanding the interrelationships between these diseases.

Parental allergic disease before and after child birth poses similar risk for childhood allergies

Whether the strength of associations between parental and child allergic diseases differs by whether the first onset of the parental disease is before or after a child's birth has never been examined and is the aim of this study. Yearly childhood asthma, allergic rhinitis, and eczema diagnoses were longitudinally regressed against the effect of a parental disease (pre- vs post-child birth) of the same type separately for each parent using generalized estimation equations. Both a maternal and paternal history of asthma were associated with childhood asthma prevalence up to 15 years of age. Effect estimates were similar for parental asthma with first onset before and after the birth of the child. The results for allergic rhinitis and eczema were less consistent. Parental allergic diseases with first onsets before and after the birth of a child both pose risks to childhood allergic disease in the offspring, especially for asthma.

Systematic review with meta-analysis: early infant feeding and coeliac disease--update 2015

BACKGROUND

New evidence emerged on early feeding practices and the risk of coeliac disease.

AIM

To systematically update evidence on these practices to find out whether there is a need to revise current recommendations.

METHODS

MEDLINE, EMBASE and the Cochrane Library were searched from July 2012 (end of last search) to February 2015 for studies of any design that assessed the effect of gluten consumption and breastfeeding on the development of coeliac disease and/or coeliac disease-related autoimmunity.

RESULTS

We identified 21 publications, including two, new, large, randomised controlled trials performed in high-risk infants. Exclusive or any breastfeeding, as well as breastfeeding at the time of gluten introduction, did not reduce the risk of developing coeliac disease during childhood. For infants at high risk of developing coeliac disease, gluten introduction at 4 months of age in very small amounts, or at 6 or 12 months of age, resulted in similar rates of coeliac disease diagnosis in early childhood. Later gluten introduction was associated with later development of coeliac specific autoimmunity and coeliac disease during childhood, but not total risk reduction. Observational studies indicate that consumption of a higher amount of gluten at weaning may increase the risk for coeliac disease development.

CONCLUSIONS

Infant feeding practices (breastfeeding, time of gluten introduction) have no effect on the risk of developing coeliac disease during childhood (at least at specific timeframes evaluated in the included studies), necessitating an update of current European recommendations.

Consensus guidelines of ECCO/ESPGHAN on the medical management of pediatric Crohn's disease

Children and adolescents with Crohn's disease (CD) present often with a more complicated disease course compared to adult patients. In addition, the potential impact of CD on growth, pubertal and emotional development of patients underlines the need for a specific management strategy of pediatric-onset CD. To develop the first evidenced based and consensus driven guidelines for pediatric-onset CD an expert panel of 33 IBD specialists was formed after an open call within the European Crohn's and Colitis Organisation and the European Society of Pediatric Gastroenterolog, Hepatology and Nutrition. The aim was to base on a thorough review of existing evidence a state of the art guidance on the medical treatment and long term management of children and adolescents with CD, with individualized treatment algorithms based on a benefit-risk analysis according to different clinical scenarios. In children and adolescents who did not have finished their growth, exclusive enteral nutrition (EEN) is the induction therapy of first choice due to its excellent safety profile, preferable over corticosteroids, which are equipotential to induce remission. The majority of patients with pediatric-onset CD require immunomodulator based maintenance therapy. The experts discuss several factors potentially predictive for poor disease outcome (such as severe perianal fistulizing disease, severe stricturing/penetrating disease, severe growth retardation, panenteric disease, persistent severe disease despite adequate induction therapy), which may incite to an anti-TNF-based top down approach. These guidelines are intended to give practical (whenever possible evidence-based) answers to (pediatric) gastroenterologists who take care of children and adolescents with CD; they are not meant to be a rule or legal standard, since many different clinical scenario exist requiring treatment strategies not covered by or different from these guidelines.

Bile acid malabsorption assessed by 7 alpha-hydroxy-4-cholesten-3-one in pediatric inflammatory bowel disease: correlation to clinical and laboratory findings

BACKGROUND AND AIMS

Measurement of 7 alpha-hydroxy-4-cholesten-3-one (C4) in serum is a semiquantitative test for bile acid malabsorption (BAM). We have previously established pediatric normal values for C4 with an upper limit of normal of 66.5 ng/mL, independent of age and sex. Here we performed the C4 test in 58 pediatric patients with Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

C4 was measured using high performance liquid chromatography (HPLC) in fasting serum samples of 44 patients with CD (range 7-19 years) and 14 with UC (4-18 years). Disease activity was assessed by the pediatric CD and UC activity indices (PCDAI and PUCAI, respectively) plus serum (CRP, ESR) and fecal inflammatory markers (calprotectin).

RESULTS

C4 concentrations were increased in 10 CD (23%) (range: 70.8-269.3 ng/mL) but only one UC patient (72.9 ng/mL). CD patients with diarrhea (n=12) had higher C4-values compared to those without (76.9 vs. 30.4 ng/mL; p=0.0043). Ileal resection in CD patients (n=10) was associated with increased C4 concentrations (81.2 vs. 24.3 ng/mL, p=0.0004). No correlation was found between C4 values and inflammatory markers. Six of 7 CD patients with persistent diarrhea but quiescent disease (PCDAI ≤12.5) had C4 values indicating BAM.

CONCLUSION

Elevated C4 concentrations indicating BAM are common in children with CD. They are associated with ileal resection and non-bloody diarrhea in the absence of active disease or elevated inflammatory markers. The C4-test identifies a subgroup of CD patients with persistent diarrhea in spite of clinical remission which may benefit from bile acid binding therapy.

Repeated exclusive enteral nutrition in the treatment of paediatric Crohn's disease: predictors of efficacy and outcome

BACKGROUND

Exclusive enteral nutrition (EEN) induces remission and mucosal healing in children with active Crohn's disease (CD).

AIM

To compare short- and long-term outcomes of the first vs. second courses of EEN, and to identify predictors of sustained remission.

METHODS

Retrospective single centre analysis of all patients with CD (6-18 years) treated with EEN over 7.5 years. Patients were excluded if exposed to anti-TNFα or corticosteroids 3 months prior to EEN. Data included disease phenotype, activity, NOD2 genotype, laboratory indices and anthropometrics. Remission and relapse were defined by mathematically weighted Paediatric Crohn's Disease Activity Index (wPCDAI) with 1-year follow-up.

RESULTS

Of 94 patients treated with EEN, 52 fulfilled inclusion criteria (31 male, mean age 13.2 years). Azathioprine was started within the first month in 33/52 patients; 26/52 received a second EEN course. First compared to second EEN revealed higher wPCDAI at start (59 vs. 40, P < 0.0001), tended to higher remission rates after 3 months (92% vs. 77%, n.s.), but showed comparable 1-year relapse rates (67% vs. 70%, median time 231 vs. 145 days, n.s.). Disease activity, weight gain and inflammatory markers showed better improvement with first EEN. Faecal calprotectin >200 μg/g during EEN was associated with shorter remission (median time 157 vs. 287 days, n.s.). Certain NOD2 genotypes were related to higher relapse rates (92% R702W or G908R vs. 50% 1007fs vs. 60% wild-type, P < 0.01).

CONCLUSIONS

Exclusive enteral nutrition induces remission in active Crohn's disease, but efficacy tends to decrease with the second course. Despite early azathioprine use, 1-year relapse rates are high, but may be related to NOD2 genotype.

Mother's body mass index and food intake in school-aged children: results of the GINIplus and the LISAplus studies

BACKGROUND/OBJECTIVES

Mother's body mass index (BMI) is a strong predictor of child BMI. Whether mother's BMI correlates with child's food intake is unclear. We investigated associations between mother's BMI/overweight and child's food intake using data from two German birth cohorts.

SUBJECTS/METHODS

Food intakes from 3230 participants were derived from parent-completed food frequency questionnaires. Intakes of 11 food groups were categorized into three levels using group- and sex-specific tertile cutoffs. Mother's BMI and overweight were calculated on the basis of questionnaire data. Multinomial regression models assessed associations between a child's food intake and mother's BMI/overweight. Linear regression models assessed associations between a child's total energy intake and mother's BMI. Models were adjusted for study region, maternal education, child's age, sex, pubertal status and energy intake and the BMIs of the child and father.

RESULTS

Mothers' BMI was associated with high meat intake in children (adjusted relative risk ratio (RRR (95% confidence interval))=1.06 (1.03; 1.09)). Mothers' overweight was associated with the meat intake (medium versus low RRR=1.30 (1.07; 1.59); high versus low RRR=1.50 (1.19; 1.89)) and egg intake (medium versus low RRR=1.24 (1.02; 1.50); high versus low RRR=1.30 (1.07; 1.60)) of children. There were no consistent associations for rest of the food groups. For every one-unit increase in mothers' BMI, the total energy intake in children increased by 9.2 kcal (3.7; 14.7). However, this effect was not significant after adjusting for children's BMI.

CONCLUSIONS

Our results suggest that mother's BMI and mother's overweight are important correlates of a child's intake of energy, meat and eggs.

Epidemiology of urticaria in infants and young children in Germany--results from the German LISAplus and GINIplus Birth Cohort Studies

BACKGROUND

Although urticaria is considered one of the most frequent skin diseases, reliable epidemiologic data are scarce.

OBJECTIVE

To evaluate the incidence and cumulative prevalence of urticaria in infants and children up to age of 10, to characterize the relationship of specific IgE levels (food and inhalative allergens) with urticaria, and to monitor the joint occurrence of urticaria with other diseases, such as eczema, asthma, and hay fever.

METHODS

The study population consisted of two prospective birth cohort studies: the LISAplus and GINIplus studies. Information on physician-diagnosed urticaria, asthma, eczema, or hay fever was collected using self-administered questionnaires completed by the parents. Blood samples were drawn, and specific immunoglobulin E measured at 2 (only LISAplus), 6 and 10 yr of age.

RESULTS

The incidence of urticaria was approximately 1% per year of age. The cumulative prevalence of urticaria in children up to the age of 10 yr was 14.5% for boys and 16.2% for girls. Cumulative prevalence of urticaria at the age of ten was significantly (p < 0.05) associated with allergic sensitization to peanut, soy, and wheat flour, but not with inhalant allergens. Both a parental history of atopy/urticaria and the children's diagnosis of asthma, eczema, and hay fever were strongly related (p < 0.0001) to the occurrence of urticaria.

CONCLUSIONS

Urticaria is a frequent event during childhood, with highest incidence in infants and preschool children. Comorbidity with atopic disease is high.

Peer problems are associated with elevated serum leptin levels in children

BACKGROUND

Leptin is thought to act as an important mediator in stress reactions. To date, no study has examined the association between psychological stress and leptin levels in children. This study aimed to assess the association between emotional symptoms and peer problems and serum leptin levels in children aged 10 years of the two population-based GINI-plus and LISA-plus birth cohorts.

METHOD

Cross-sectional data from 2827 children aged 10 years were assessed with regard to leptin concentrations in serum and behavioral problems using the parent-reported Strengths and Difficulties Questionnaire (SDQ). Linear regression modeling was applied to determine the likelihood of elevated leptin levels in children with emotional symptoms and peer problems, controlling for socio-economic status (SES), body mass index (BMI), fasting serum leptin levels, pubertal development and sex hormones.

RESULTS

We found that increases in emotional symptoms (exp β adj = 1.03, s.e. = 0.02, p < 0.04) and peer problems (exp β adj = 1.05, s.e. = 0.01, p = 0.0001) were significantly associated with higher serum leptin levels controlled for BMI and sociodemographic factors. Similar results were found when the fasting serum leptin sample was examined (exp β adj = 1.08, s.e. = 0.04, p = 0.0294). Gender-stratified analyses showed a significant relationship between serum leptin and peer problems in girls (exp β adj = 1.05, s.e. = 0.02, p = 0.03), and a borderline significant association in boys (exp β adj = 1.04, s.e. = 0.02, p = 0.05).

CONCLUSIONS

Children with peer problems have higher stress and eat more, acquire a higher body fat mass and thus, through increased leptin resistance, exhibit higher leptin levels.

Is a child's growth pattern early in life related to serum adipokines at the age of 10 years?

BACKGROUND/OBJECTIVES

Growth parameters during infancy and early childhood might predict adipokine levels later in life. This study investigates the association between peak growth velocities, body mass index (BMI) and age at adiposity rebound (AR), with leptin and adiponectin levels at age 10 years.

SUBJECTS/METHODS

Peak height (PHV) and weight (PWV) velocities were calculated from height and weight measurements obtained between birth and age 2 years from 2880 children participating in the GINIplus (German Infant Nutritional Intervention plus environmental and genetic influences on allergy development) and LISAplus (Influences of Lifestyle-Related Factors on the Immune System and the Development of Allergies in Childhood plus Air Pollution and Genetics) birth cohorts. BMI and age at AR were calculated using BMI measurements between age 1.5 and 12 years. Blood samples were collected during a physical examination at age 10. Adiponectin and leptin levels were measured by radioimmunoassay. Linear regression models were fitted after adjustment for potential confounding factors and results are presented per interquartile range increase in the exposure.

RESULTS

Age at AR was negatively associated with leptin in males and females (percent difference β*: -41.71%; 95% confidence interval: (-44.34;-38.96) and β*: -43.22%; (-45.59; -40.75), respectively). For both males and females PWV (β*: 14.23%; (7.60; 21.26) and β*: 18.54%; (10.76; 26.87), respectively) and BMI at AR (β*: 63.08%; (55.04; 71.53) and β*: 67.02%; (59.30; 75.10), respectively) were positively associated with leptin levels. PHV showed a positive effect on leptin in females only (β*: 10.75%; (3.73; 18.25)). Growth parameters were not significantly associated with adiponectin except for age at AR among females (β: 0.75 ng/ml; (0.42; 1.09)) and PWV among males (β: 0.45 ng/ml; (0.11; 0.79)).

CONCLUSION

Growth patterns in early life may be associated with leptin levels at age 10 years.

Long-term exposure to traffic-related air pollution and insulin resistance in children: results from the GINIplus and LISAplus birth cohorts

AIMS/HYPOTHESIS

Epidemiological studies that have examined associations between long-term exposure to traffic-related air pollution and type 2 diabetes mellitus in adults are inconsistent, and studies on insulin resistance are scarce. We aimed to assess the association between traffic-related air pollution and insulin resistance in children.

METHODS

Fasting blood samples were collected from 397 10-year-old children in two prospective German birth cohort studies. Individual-level exposures to traffic-related air pollutants at the birth address were estimated by land use regression models. The association between air pollution and HOMA of insulin resistance (HOMA-IR) was analysed using a linear model adjusted for several covariates including birthweight, pubertal status and BMI. Models were also further adjusted for second-hand smoke exposure at home. Sensitivity analyses that assessed the impact of relocating, study design and sex were performed.

RESULTS

In all crude and adjusted models, levels of insulin resistance were greater in children with higher exposure to air pollution. Insulin resistance increased by 17.0% (95% CI 5.0, 30.3) and 18.7% (95% CI 2.9, 36.9) for every 2SDs increase in ambient NO2 and particulate matter ≤10 μm in diameter, respectively. Proximity to the nearest major road increased insulin resistance by 7.2% (95% CI 0.8, 14.0) per 500 m.

CONCLUSIONS/INTERPRETATION

Traffic-related air pollution may increase the risk of insulin resistance. Given the ubiquitous nature of air pollution and the high incidence of insulin resistance in the general population, the associations examined here may have potentially important public health effects despite the small/moderate effect sizes observed.

Association of gas cooking with children's respiratory health: results from GINIplus and LISAplus birth cohort studies

Previous studies have found inconsistent results on the association between asthma in children and gas cooking emissions. We aimed to assess the effects of the long-term exposure to gas cooking on the onset of asthma and respiratory symptoms, focusing on wheezing, in children from two German birth cohorts: LISAplus and GINIplus. A total of 5078 children were followed until the age of 10 years. Asthma, wheezing, gas cooking, and exposure to other indoor factors were assessed through parental reported questionnaires administered periodically. Logistic and multinomial regressions adjusting for potential confounders were performed. The prevalence of asthma and persistent wheezing was higher among children exposed to gas cooking but the results were not statistically significant. Exposure to gas cooking was positively associated (P-value < 0.05) with exposure to other indoor factors (dampness, environmental tobacco smoke, and pets). Our results did not show a statistically significant association between the exposure to gas cooking and children's respiratory health.

PRACTICAL IMPLICATIONS

These analyses are consistent with the assumption of no effect of the exposure to low doses of nitrogen dioxide. The strong positive associations found between gas cooking and other indoor factors highlight the importance of considering other indoor factors when assessing health effects of gas cooking. Low-dose exposure to indoor nitrogen dioxide through gas cooking might not contribute to increase the risk of asthma and respiratory symptoms in children.

Systematic review: early infant feeding and the prevention of coeliac disease

BACKGROUND

PREVENTCD, Prevent Coeliac Disease, is an international project investigating the hypothesis of possible induction of tolerance to gluten in genetically predisposed children through introducing small quantities of gluten during the period of breastfeeding.

AIM

To summarise current knowledge on the possible relationship between early feeding practices and the risk of coeliac disease (CD).

METHODS

The Cochrane Library, MEDLINE, and EMBASE databases were searched in May 2011, and the search was updated in January 2012, and again in July 2012.

RESULTS

Breastfeeding (BF) and CD: some studies show a protective effect of BF, while others show no effect. No studies have shown a long-term preventive effect. BF at the time of gluten introduction and CD: Results from a meta-analysis of five observational case-control studies suggest that BF at gluten introduction is associated with a lower risk of CD compared with formula feeding. It is unclear whether BF provides a permanent protection or only delays the onset of CD. Timing of gluten introduction: The data suggest that both early (≤4 months) and late (≥7 months) introduction of gluten may increase the risk of CD. Amount of gluten at weaning (and later) and CD: One incident case-referent study documented that the introduction of gluten in large amounts compared with small or medium amounts increased the risk of CD.

CONCLUSIONS

In the absence of clear evidence, in order to decrease the risk of later coeliac disease, it is reasonable to avoid both early (<4 months) and late (≥7 months) introduction of gluten, and to introduce gluten while the infant is still being breastfed. Future studies may clarify the remaining uncertainties.

Growth velocity during infancy and onset of asthma in school-aged children

BACKGROUND

Growth velocities during infancy might affect the risk of asthma in childhood. This study examines the association between peak height and weight velocities during the first 2 years of life and onset of asthma and wheeze up to 10 years of age.

METHODS

Data from 9086 children who participated in the GINIplus and LISAplus birth cohorts were analyzed. Information on asthma was requested annually from 1 to 10 years and information on wheeze at 1, 2, 4, 6, and 10 years. Peak height and weight velocities were calculated using height and weight measurements obtained between birth and 2 years of age. Cox proportional hazards models and generalized linear mixed models were calculated after adjustment for potential confounding factors including birth weight and body mass index at 10 years of age.

RESULTS

Per interquartile range increase in peak weight velocity (PWV), the risk of asthma increased significantly (adjHR: 1.22; CI: 1.02-1.47). The relationship between peak height velocity (PHV) and onset of asthma was nonsignificant (adjHR: 1.08; CI: 0.88-1.31). Wheeze was not significantly associated with PHV or with PWV (adjOR: 1.07; CI: 0.64-1.77 and adjOR: 1.11; CI: 0.68-1.79, respectively).

CONCLUSIONS

Weight gain during infancy is positively associated with physician-diagnosed asthma in school-aged children.

Long-term maintenance treatment with omeprazole in children with healed erosive oesophagitis: a prospective study

BACKGROUND

Short-term studies show that PPIs heal erosive esophagitis in children. There are no prospective studies that examine long-term maintenance therapy of erosive esophagitis in children with and without underlying GERD-predisposing disorders.

AIM

To determine prospectively the dose of omeprazole needed to maintain remission of erosive oesophagitis and reflux symptoms in children.

METHODS

Patients aged 1-16 years with healed erosive reflux oesophagitis after omeprazole treatment (0.7-3.5 mg/kg/day) entered a 21-month maintenance phase where they initially received half the dose of omeprazole required to heal. Endoscopy was performed after 3, 12 and 21 months. The omeprazole dose was increased if erosive oesophagitis or reflux symptoms recurred.

RESULTS

A total of 46 patients entered the study and 32 completed it. Of these, 17 (53%) remained on the maintenance dose, 12 (38%) returned to their healing dose and 3 (9%) ended the study on a dose higher than their healing dose. Three-quarters of the completers (24/32) had no erosive oesophagitis relapse. Four patients (13%) had relapse of only erosive oesophagitis, 4 (13%) had relapse of erosive oesophagitis and symptoms, and 10 (31%) had only symptomatic relapse. Of the 46 patients, 48% had GERD-predisposing disorders (neurological impairment or oesophageal atresia). Overall, 62.5% (5/8) of patients who had an erosive oesophagitis relapse had a GERD-predisposing disorder versus 33.3% (8/24) of those who did not.

CONCLUSIONS

Remission of erosive oesophagitis is maintained with omeprazole treatment for at least 21 months in most children aged 1-16 years, and the drug is well tolerated. To maintain remission, some 60% of patients require more than half the dose required for healing. In children with GERD-predisposing conditions, GERD is often chronic and relapsing, and requires long-term management.

European Society for Pediatric Gastroenterology, Hepatology, and Nutrition guidelines for the diagnosis of coeliac disease

OBJECTIVE

Diagnostic criteria for coeliac disease (CD) from the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN) were published in 1990. Since then, the autoantigen in CD, tissue transglutaminase, has been identified; the perception of CD has changed from that of a rather uncommon enteropathy to a common multiorgan disease strongly dependent on the haplotypes human leukocyte antigen (HLA)-DQ2 and HLA-DQ8; and CD-specific antibody tests have improved.

METHODS

A panel of 17 experts defined CD and developed new diagnostic criteria based on the Delphi process. Two groups of patients were defined with different diagnostic approaches to diagnose CD: children with symptoms suggestive of CD (group 1) and asymptomatic children at increased risk for CD (group 2). The 2004 National Institutes of Health/Agency for Healthcare Research and Quality report and a systematic literature search on antibody tests for CD in paediatric patients covering the years 2004 to 2009 was the basis for the evidence-based recommendations on CD-specific antibody testing.

RESULTS

In group 1, the diagnosis of CD is based on symptoms, positive serology, and histology that is consistent with CD. If immunoglobulin A anti-tissue transglutaminase type 2 antibody titers are high (>10 times the upper limit of normal), then the option is to diagnose CD without duodenal biopsies by applying a strict protocol with further laboratory tests. In group 2, the diagnosis of CD is based on positive serology and histology. HLA-DQ2 and HLA-DQ8 testing is valuable because CD is unlikely if both haplotypes are negative.

CONCLUSIONS

The aim of the new guidelines was to achieve a high diagnostic accuracy and to reduce the burden for patients and their families. The performance of these guidelines in clinical practice should be evaluated prospectively.

FADS gene cluster modulates the effect of breastfeeding on asthma. Results from the GINIplus and LISAplus studies

BACKGROUND

  The protective effect of breastfeeding (BF) on the development of asthma has been widely recognized, even if not all results have been consistent. Gene variants of the FADS gene cluster have a major impact on fatty acid composition in blood and in breast milk. Therefore, we evaluated the influence of the FADS1 FADS2 gene cluster polymorphisms on the association between BF and asthma.

METHODS

  The analysis was based on data (N=2245) from two German prospective birth cohort studies. Information on asthma and BF during the first 6 months was collected using questionnaires completed by the parents. Logistic regression modelling was used to analyse the association between exclusive BF and ever having asthma stratified by genotype.

RESULTS

  In the stratified analyses, BF for 3 or 4 months after birth had a protective effect for heterozygous and homozygous carriers of the minor allele (adjusted odds ratio between 0.37 (95% CI: 0.18-0.80) and 0.42 (95% CI: 0.20-0.88). Interaction terms of BF with genotype were significant and ranged from -1.17 (P-value: 0.015) to -1.33 (0.0066). Moreover, heterozygous and homozygous carriers of the minor allele who were exclusively breastfed for 5 or 6 months after birth had a reduced risk of asthma [0.32 (0.18-0.57) to 0.47 (0.27-0.81)] in the stratified analyses. For individuals carrying the homozygous major allele, BF showed no significant effect on the development of asthma.

CONCLUSIONS

  The association between exclusive BF and asthma is modified by the genetic variants of FADS genotypes in children.

FADS gene variants modulate the effect of dietary fatty acid intake on allergic diseases in children

BACKGROUND

The association between dietary fatty acid intake and the development of atopic diseases has been inconsistent. This could be due to inter-individual genetic differences in fatty acid metabolism.

OBJECTIVE

The aim of the current study was to assess the influence of FADS1 FADS2 gene cluster polymorphisms on the association between dietary fatty acid intake and atopic diseases and allergic sensitization in 10-year-old children.

METHODS

The analysis was based on data from two German prospective birth cohort studies. Data on margarine and fatty acid intake were collected using a food frequency questionnaire. Information on atopic diseases was collected using a questionnaire completed by the parents. Specific IgE against common food and inhalant allergens were measured. Six variants of the FADS1 FADS2 gene cluster (rs174545, rs174546, rs174556, rs174561, rs174575 and rs3834458) were tested. Logistic regression modelling, adjusted for gender, age, maternal education level and study centre, was used to analyse the association between fatty acid intake and atopic diseases stratified by genotype.

RESULTS

No significant association was found between the six FADS single nucleotide polymorphisms (SNPs) and allergic diseases or atopic sensitization. The total n-3/total n-6 ratio was positive associated with an increased risk of hayfever in homozygous major allele carriers ranging from an adjusted odds ratios of 1.25 (95%-CI: 1.00-1.57) to 1.31 (95%-CI: 1.01-1.69) across the six tested SNPs although this association was not significant anymore after correcting for multiple testing. Daily margarine intake was significantly associated with asthma [1.17 (1.03-1.34) to 1.22 (1.06-1.40)] in individuals carrying the homozygous major allele. This association was also significant after correcting for multiple testing.

CONCLUSIONS & CLINICAL RELEVANCE

The association between dietary intake of fatty acids and allergic diseases might be modulated by FADS gene variants in children.

Respiratory health in children, and indoor exposure to (1,3)-β-D-glucan, EPS mould components and endotoxin

For a long time, exposure to mould and dampness-derived microbial components was considered a risk factor for the development of respiratory diseases and symptoms. Some recent studies suggested that early childhood exposure to mould components, such as (1,3)-β-D-glucan and extracellular polysaccharides (EPSs), may protect children from developing allergy. We investigated the association of exposure to (1,3)-β-D-glucan, EPS and endotoxin with asthma and allergies in 6-yr-old children. This investigation was the follow-up to a nested case-control study among three European birth cohorts. Children from two ongoing birth cohort studies performed in Germany (n = 358) and one in the Netherlands (n = 338) were selected. Levels of (1,3)-β-D-glucan, EPS and endotoxin were measured in settled house dust sampled from children's mattresses and living-room floors when the children were, on average, 5 yrs of age. At the age of 6 yrs, health outcome information was available for 678 children. In the two German subsets, domestic EPS and endotoxin exposure from children's mattresses were significantly negatively associated with physician-diagnosed asthma (OR per interquartile range increase 0.60 (95% CI 0.39-0.92) and 0.55 (95% CI 0.31-0.97), respectively). In addition, EPS exposure was inversely related to physician-diagnosed allergic rhinitis (OR 0.50, 95% CI 0.31-0.81). For the Dutch population, no associations were observed between exposure to microbial agents and respiratory health outcomes. We found inverse associations between domestic exposure to EPS and endotoxin from children's mattresses, and doctor-diagnosed asthma and rhinitis in German, but not in Dutch, school children. The reasons for the differences between countries are not clear.

Delayed gastric emptying in patients with Prader Willi Syndrome

BACKGROUND

A 15 year old girl with Prader-Willi Syndrome (PWS) died of gastric rupture. Systematic literature research revealed seven case reports of PWS patients with acute gastric dilatation, two had a lethal course. The objective of this study was to determine if delayed gastric emptying in PWS patients might contribute to gastric dilatation.

METHODS

Gastric emptying was measured in eight patients with PWS by nucleotid scintigraphy after a standardized test meal.

RESULTS

Median age was 17.8 years (range 10.1-19.5). Median BMI of the male patients was 29.5 (range 18.4-34.8), of the female patients 28 (range 20.0-44.8). Half time of gastric emptying was delayed in five of the eight patients (median 78.5 minutes, range 59-134).

CONCLUSION

Scintigraphic measurement of gastric emptying in eight PWS patients revealed delay in comparison to normal values. This might be a risk factor for gastric dilatation and rupture in patients with PWS.

Association of the interleukin-23 receptor gene variant rs11209026 with Crohn's disease in German children

AIM

Genome-wide association studies have described variants within the interleukin-23 receptor (IL23R) locus to be associated with Crohn's disease (CD) and ulcerative colitis (UC). We investigated the association of rs11209026 (p.Arg381Gln) and rs7517847 (c.799-3588T>G) into German paediatric inflammatory bowel disease (IBD) patients and analysed IL23R transcriptional activity in colonic tissues.

METHODS

The rs11209026 and rs7517847 nucleotide substitutions were determined in 353 German children with IBD (221 CD, 132 UC) and 253 controls using pre-designed TaqMan((R)) SNP genotyping assays. In selected IBD patients and controls, IL23R mRNA expression was measured using real-time PCR.

RESULTS

The prevalence of the rs11209026 A allele was lower in CD patients, but not in UC patients, when compared with controls (1.8% vs 7.1%, p < 0.01). The rs7517847 variant, in contrast, was associated neither with CD nor with UC. IL23R expression was variable in IBD patients compared with controls without significant overexpression or downregulation.

CONCLUSION

Our study provides additional support for the strong protection of the rs11209026 (p.Arg381Gln) variant against paediatric CD. IL23R was expressed in both CD and UC with a great variability. However, expression levels showed no significant association with the disease.