Association between Maternal Perinatal Stress and Depression on Infant DNA Methylation in the First Year of Life

Maternal stress and depression during pregnancy and the first year of the infant's life affect a large percentage of mothers. Maternal stress and depression have been associated with adverse fetal and childhood outcomes as well as differential child DNA methylation (DNAm). However, the biological mechanisms connecting maternal stress and depression to poor health outcomes in children are still largely unknown. Here we aim to determine whether prenatal stress and depression are associated with changes in cord blood mononuclear cell DNAm (CBMC-DNAm) in newborns (n = 119) and whether postnatal stress and depression are associated with changes in peripheral blood mononuclear cell DNAm (PBMC-DNAm) in children of 12 months of age (n = 113) from the Canadian Healthy Infant Longitudinal Development (CHILD) cohort. Stress was measured using the 10-item Perceived Stress Scale (PSS) and depression was measured using the Center for Epidemiologic Studies Depression Questionnaire (CESD). Both stress and depression were measured at 18 weeks and 36 weeks of pregnancy and six months and 12 months postpartum. We conducted epigenome-wide association studies (EWAS) using robust linear regression followed by a sensitivity analysis in which we bias-adjusted for inflation and unmeasured confounding using the bacon and cate methods. To investigate the cumulative effect of maternal stress and depression, we created composite prenatal and postnatal adversity scores. We identified a significant association between prenatal stress and differential CBMC-DNAm at 8 CpG sites and between prenatal depression and differential CBMC-DNAm at 2 CpG sites. Additionally, we identified a significant association between postnatal stress and differential PBMC-DNAm at 8 CpG sites and between postnatal depression and differential PBMC-DNAm at 11 CpG sites. Using our composite scores, we further identified 2 CpG sites significantly associated with prenatal adversity and 7 CpG sites significantly associated with postnatal adversity. Several of the associated genes, including PLAGL1, HYMAI, BRD2, and ERC2 have been implicated in adverse fetal outcomes and neuropsychiatric disorders. This suggested that differential DNAm may play a role in the relationship between maternal mental health and child health.

A decade of progress in juvenile idiopathic athritis treatments and outcomes in Canada: results from ReACCh-Out and the CAPRI registry

OBJECTIVE

To assess changes in juvenile idiopathic arthritis (JIA) treatments and outcomes in Canada, comparing a 2005-2010 and a 2017-2021 inception cohorts.

METHODS

Patients enrolled within three months of diagnosis in the Research in Arthritis in Canadian Children Emphasizing Outcomes (ReACCh-Out) and the Canadian Alliance of Pediatric Rheumatology Investigators Registry (CAPRI) cohorts were included. Cumulative incidences of drug starts and outcome attainment within 70 weeks of diagnosis were compared with Kaplan Meier survival analysis and multivariable Cox regression.

RESULTS

The 2005-2010 and 2017-2021 cohorts included 1128 and 721 patients, respectively. JIA category distribution and baseline clinical juvenile idiopathic arthritis disease activity (cJADAS10) scores at enrolment were comparable. By 70 weeks, 6% of patients (95% CI 5, 7) in the 2005-2010 and 26% (23, 30) in the 2017-2021 cohort had started a biologic DMARD (bDMARD), and 43% (40, 47) and 60% (56, 64) had started a conventional DMARD (cDMARD), respectively. Outcome attainment was 64% (61, 67) and 83% (80, 86) for Inactive disease (Wallace criteria), 69% (66, 72) and 84% (81, 87) for minimally active disease (cJADAS10 criteria), 57% (54, 61) and 63% (59, 68) for pain control (<1/10), and 52% (47, 56) and 54% (48, 60) for a good health-related quality of life.

CONCLUSION

Although baseline disease characteristics were comparable in the 2005-2010 and 2017-2021 cohorts, cDMARD and bDMARD use increased with a concurrent increase in minimally active and inactive disease. Improvements in parent and patient reported outcomes were smaller than improvements in disease activity.

Investigating the effect of early life antibiotic use on asthma and allergy risk in over 600 000 Canadian children: a protocol for a retrospective cohort study in British Columbia and Manitoba

INTRODUCTION

Allergic conditions, such as asthma, hay fever and eczema, are some of the most common conditions impacting children globally. There is a strong incentive to study their determinants to improve their prevention. Asthma, hay fever and eczema are influenced through the same immunological pathway and often copresent in children ('the atopic march'). Increasing evidence shows a link between infant antibiotic use and the risk of childhood atopic conditions, mediated through gut microbial dysbiosis during immune system maturation, however, the potential for confounding remains. This study will investigate the relationship between infant antibiotic use and risk of allergic conditions in British Columbian and Manitoban children born over 10 years, adjusting for relevant confounders.

METHODS AND ANALYSIS

Provincial administrative datasets will be linked to perform comparable retrospective cohort analyses, using Population Data BC and the Manitoba Population Research Data Repository. All infants born between 2001 and 2011 in BC and Manitoba will be included (approximately 460 000 and 162 500 infants, respectively), following up to age 7. Multivariable logistic regression will determine the outcome risk by the fifth birthday among children who did and did not receive antibiotics before their first birthday. Clinical, demographic and environmental covariates will be explored, and sensitivity analyses performed to reduce confounding by indication.

ETHICS AND DISSEMINATION

The University of British Columbia Research Ethics Board (H19-03255) and University of Manitoba Ethics Board (HS25156 (H2021:328)) have approved this study. Data stewardship committees for all administrative datasets have granted permissions, facilitated by Population Data BC and the Manitoba Centre for Health Policy. Permissions from the Canadian Health Infant Longitudinal Development Study are being sought for breastfeeding data (CP185). Findings will be published in scientific journals and presented at infectious disease and respiratory health conferences. A stakeholder committee will guide and enhance sensitive and impactful communication of the findings to new parents.

Correction: Gestational age at birth and body size from infancy through adolescence: An individual participant data meta-analysis on 253,810 singletons in 16 birth cohort studies

[This corrects the article DOI: 10.1371/journal.pmed.1004036.].

Gestational age at birth and body size from infancy through adolescence: An individual participant data meta-analysis on 253,810 singletons in 16 birth cohort studies

BACKGROUND

Preterm birth is the leading cause of perinatal morbidity and mortality and is associated with adverse developmental and long-term health outcomes, including several cardiometabolic risk factors and outcomes. However, evidence about the association of preterm birth with later body size derives mainly from studies using birth weight as a proxy of prematurity rather than an actual length of gestation. We investigated the association of gestational age (GA) at birth with body size from infancy through adolescence.

METHODS AND FINDINGS

We conducted a two-stage individual participant data (IPD) meta-analysis using data from 253,810 mother-child dyads from 16 general population-based cohort studies in Europe (Denmark, Finland, France, Italy, Norway, Portugal, Spain, the Netherlands, United Kingdom), North America (Canada), and Australasia (Australia) to estimate the association of GA with body mass index (BMI) and overweight (including obesity) adjusted for the following maternal characteristics as potential confounders: education, height, prepregnancy BMI, ethnic background, parity, smoking during pregnancy, age at child's birth, gestational diabetes and hypertension, and preeclampsia. Pregnancy and birth cohort studies from the LifeCycle and the EUCAN-Connect projects were invited and were eligible for inclusion if they had information on GA and minimum one measurement of BMI between infancy and adolescence. Using a federated analytical tool (DataSHIELD), we fitted linear and logistic regression models in each cohort separately with a complete-case approach and combined the regression estimates and standard errors through random-effects study-level meta-analysis providing an overall effect estimate at early infancy (>0.0 to 0.5 years), late infancy (>0.5 to 2.0 years), early childhood (>2.0 to 5.0 years), mid-childhood (>5.0 to 9.0 years), late childhood (>9.0 to 14.0 years), and adolescence (>14.0 to 19.0 years). GA was positively associated with BMI in the first decade of life, with the greatest increase in mean BMI z-score during early infancy (0.02, 95% confidence interval (CI): 0.00; 0.05, p < 0.05) per week of increase in GA, while in adolescence, preterm individuals reached similar levels of BMI (0.00, 95% CI: -0.01; 0.01, p 0.9) as term counterparts. The association between GA and overweight revealed a similar pattern of association with an increase in odds ratio (OR) of overweight from late infancy through mid-childhood (OR 1.01 to 1.02) per week increase in GA. By adolescence, however, GA was slightly negatively associated with the risk of overweight (OR 0.98 [95% CI: 0.97; 1.00], p 0.1) per week of increase in GA. Although based on only four cohorts (n = 32,089) that reached the age of adolescence, data suggest that individuals born very preterm may be at increased odds of overweight (OR 1.46 [95% CI: 1.03; 2.08], p < 0.05) compared with term counterparts. Findings were consistent across cohorts and sensitivity analyses despite considerable heterogeneity in cohort characteristics. However, residual confounding may be a limitation in this study, while findings may be less generalisable to settings in low- and middle-income countries.

CONCLUSIONS

This study based on data from infancy through adolescence from 16 cohort studies found that GA may be important for body size in infancy, but the strength of association attenuates consistently with age. By adolescence, preterm individuals have on average a similar mean BMI to peers born at term.

'Gut health' and the microbiome in the popular press: a content analysis

OBJECTIVE

Extensive research and important discoveries on the microbiome have led to a growth in media coverage. This study explores how the microbiome has been portrayed in press sources popular among American and Canadian audiences.

DESIGN

Content analysis.

METHODS

Using the FACTIVA Database, we compiled a finalised data set of (N=830) articles from press sources popular among American and Canadian audiences which were published between 1 January 2018 and 11 October 2019 and which contained at least one of the following search terms: 'microbiome', 'microbiota', 'gut health', 'healthy gut', 'unhealthy gut', 'gut bacteria', 'probiotic' or 'probiotics.' We performed content analysis on the articles to determine how often ideas of the microbiome were presented as beneficial, in which health contexts, and whether actions could be taken to reap stated benefits. We compared this portrayal of benefits with critical portrayals of the microbiome.

RESULTS

Almost all of the articles (94%) described health benefits associated with the microbiome with many (79%) describing actions which could be taken to reap stated benefits. Articles most often described health benefits in more broad, general context (34%) and most commonly outlined actions related to food/drug (45%) as well as probiotic (27%) intake. Only some articles (19%) provided microbiome-related critiques or limitations. Some of the articles (22%) were focused on highlighting specific research developments, and in these articles, critiques or limitations were more common.

CONCLUSIONS

Articles discussing the microbiome published for American and Canadian audiences typically hype the microbiome's impact and popularise gut health trends while only offering a little in the way of communicating microbiome science. Lifestyle choices including nutrition, taking probiotics, stress management and exercise are often promoted as means of reaping the microbiome-related health benefits. The trend of actionable 'gut health' is foregrounded over more evidence-based descriptions of microbiome science.

Maternal Prenatal Supplement Intake, but Not Dietary Patterns, Is Associated With Human Milk Microbiota Composition in the CHILD Cohort Study

Objectives

The human milk microbiome plays an important role in child health and is affected by several factors. We aim to examine whether prenatal diet and supplement intake are associated with human milk microbiota composition.

Methods

Among the CHILD Cohort Study members, 771 mothers provided data on diet and supplement intake during pregnancy and a milk sample between 2–6 months postpartum. Maternal diet was assessed using a food frequency questionnaire adapted from the Fred Hutchinson Cancer Center. Three dietary patterns were derived using principal component analysis: plant-based, Western, and balanced. The milk microbiome was analyzed using 16S rRNA gene sequencing. Associations between maternal intake and microbial diversity (Shannon index) and genera relative abundances were examined in R using the Wilcoxon signed-rank test adjusted for multiple comparisons.

Results

Maternal supplement intake, but not dietary patterns, was associated with human milk microbiota composition. Approximately 88% of the mothers took prenatal multivitamins. Mothers who took fish oil (18%) or folate supplements (17%) during pregnancy had lower microbial diversity than those who did not (mean ± SD: 1.61 ± 0.64 v. 1.79 ± 0.66 for fish oil [p = 0.01] and 1.64 ± 0.64 v. 1.78 ± 0.67 for folate [P = 0.02]). Mothers who took vitamin C supplements (4%), compared to those who did not, had higher microbial diversity (1.99 ± 0.59 v. 1.72 ± 0.65 [P = 0.03]) and higher relative abundance of Veillonella but lower abundances of Finegoldia and Stenotrophomonas (pfdr &lt; 0.05). Compared to the respective supplement non-takers, mothers who took vitamin D supplements (23%) had lower abundance of unclassified Comamonadaceae (pfdr &lt; 0.05), while mothers who took Ca-containing antacids (11%) had higher abundances of Streptococcus, unclassified Gemellaceae, and Rothia but lower abundances of unclassified Comamonadaceae and unclassified Enterobacteriaceae (pfdr &lt; 0.05).

Conclusions

Human milk microbiota composition differed among mothers who took specific prenatal supplements. Further analysis is needed to explore additional associations while accounting for covariates that impact the human milk microbiome.

Funding Sources

CIHR and AllerGen NCE funded the CHILD Cohort Study. The Canadian Lung Association and Canadian Respiratory Research Network funded the milk microbiome sequencing.

Dibutyl Phthalate Augments Allergen-induced Lung Function Decline and Alters Human Airway Immunology. A Randomized Crossover Study

Rationale: Phthalates are a group of chemicals used in common commercial products. Epidemiological studies suggest that phthalate exposure is associated with development or worsening of allergic diseases such as asthma. However, effects of dibutyl phthalate (DBP) or other phthalates found in high concentrations in indoor air have never been examined in allergic individuals in a controlled exposure setting.Objectives: To investigate the airway effects in humans caused by inhalation of a known concentration of a single phthalate, DBP.Methods: In a randomized crossover study, 16 allergen-sensitized participants were exposed to control air or DBP for 3 hours in an environmental chamber followed immediately by an allergen inhalation challenge. Bronchoalveolar wash and lavage were obtained 24 hours after exposure. Lung function, early allergic response, airway responsiveness, inflammation, immune mediators, and immune cell phenotypes were assessed after DBP exposure.Measurements and Main Results: DBP exposure increased the early allergic response (21.4% decline in FEV₁ area under the curve, P = 0.03). Airway responsiveness was increased by 48.1% after DBP exposure in participants without baseline hyperresponsiveness (P = 0.01). DBP increased the recruitment of BAL total macrophages by 4.6% (P = 0.07), whereas the M2 macrophage phenotype increased by 46.9% (P = 0.04). Airway immune mediator levels were modestly affected by DBP.Conclusions: DBP exposure augmented allergen-induced lung function decline, particularly in those without baseline hyperresponsiveness, and exhibited immunomodulatory effects in the airways of allergic individuals. This is the first controlled human exposure study providing biological evidence for phthalate-induced effects in the airways.Clinical trial registered with www.clinicaltrials.gov (NCT02688478).

1146. Antibiotic Use in Infants Predicts Asthma Rate in Children 1–4 years at Fine Geographic Scale

Background

Early-life exposure to antibiotics is associated with childhood asthma. We previously reported that a dramatic drop in infant antibiotic use is correlated with a decline in asthma incidence in children in British Columbia (BC). This study aims to see whether antibiotic exposure predicts asthma at a fine geographic scale after adjustment for known covariates.

Methods

We used prescribing data from BC PharmaNet, a population-based database capturing all outpatient prescribing for BC population (n = 4.7 million). Prescribing rates for infants <1 year were calculated as prescriptions per 1000 population per year using age and sex-specified denominator estimates. Age-adjusted aggregate asthma incidence data for children 1–4 years were obtained from the BC Ministry of Health Chronic Disease Registry. The disease identification uses a standard case definition making using of diagnostic codes (ICD9-493 and ICD10-J45) in BC’s universal hospital and physician billing databases and relevant asthma-specific drug data from BC PharmaNet. We modeled the association between antibiotic prescribing rate and asthma incidence in 91 Local Health Areas using multivariable Poisson regression employing a generalized linear mixed-effects model adjusting for covariates.

Results

Between 2000 and 2014, the annual asthma incidence (ages 1–4 years) fell 26% from 27.3 (95% CI: 26.5–28.0) to 20.2 (95% CI: 19.5–20.8) per 1000 population. For children aged 1–4 years in 2000, the average proportion of infants exposed to one or more courses of antibiotics fell from 66.9 to 32.1% over the same interval. Antibiotic was a significant predictor of asthma rate (IRR=1.24 per 10% absolute increase in antibiotic prescribing; 95% CI: 1.19–1.27). Other covariates that remained significant in the model included male sex (IRR=1.56; 95% CI: 1.53–1.58), and atmospheric particulate matter PM 2.5 (IRR=1.08 per interquartile increase; 95% CI: 1.06–1.10).

Conclusion

Our findings suggest that antibiotic exposure in the first year of life increases the risk of being diagnosed with asthma later in childhood. This is congruent with similar findings at the individual level in a prospective cohort of Canadian children that also points to a pathway through altered gut microbiota.

Disclosures

All authors: No reported disclosures.

Clostridioides Difficile Colonization Is Differentially Associated with Gut Microbiota Composition in Breastfed versus Formula Fed Infants (OR01-02-19)

Objectives

Colonization with Clostridioides difficile occurs in up to half of infants and is predicted by formula feeding. Although this microbe does not appear to pose any immediate risks for infants, its presence has been associated with susceptibility to chronic disease later in childhood, perhaps by promoting changes in the gut microbiome that may increase opportunity for colonization of pathogenic bacteria. We explored these compositional changes in exclusively breastfed, partially breastfed and exclusively formula fed infants to describe the microbial community and C. difficile colonization in infants with distinct diets.

Methods

This study includes 1562 infants enrolled in the Canadian Healthy Infant Longitudinal Development (CHILD) Study. Infants provided a fecal sample at 3–4 months of age (Mean: 3.56, SD: 1.00) which was analyzed using 16S rRNA sequencing and targeted qPCR for C. difficile. Mode of feeding was recorded in a questionnaire at a 3 month follow-up visit. C. difficile colonization was defined as positive detection (CD+) in the fecal sample (reference: not present, CD-). Multivariate association with linear models (MaAslin) was used to determine changes in microbiota composition following arsine-square root transformation of relative abundances and FDR correction.

Results

The prevalence of C. difficile colonization among all infants was 30.9%. Colonization rates differed among feeding groups: 22.63% of exclusively breastfed infants, 35.96% of partially breastfed infants and 49.63% of exclusively formula fed infants (P < 0.001). Microbes of the genus Bifidobacterium were decreased in CD + exclusively breastfed infants compared to non-carriers of the same diet (q = 0.02). Additionally, Blautia, Coprococcus and Clostridium, of the Lachnospiraceae family, and microbes of the Bacteroidetes phylum were of higher relative abundance (all q < 0.01) in breastfed CD + infants (both partial and exclusive). In exclusively formula fed infants, C. difficile colonization was not significantly associated with microbiota composition.

Conclusions

C. difficile colonization may have a dysbiotic effect on the gut microbiota composition of breastfed infants, changes which have previously been associated with childhood atopy and obesity.

Funding Sources

Canadian Institutes of Health Research (CIHR).

AllerGen Network of Centres of Excellence (NCE)

MALT1-deficient CD4 T cells exhibit decreased IL-2 secretion and impaired Th1 and Th17 differentiation

A child admitted to British Columbia Children’s Hospital displayed a novel clinical presentation of immune dysregulation, exhibiting lymphocytic infiltration and severe inflammation of the intestinal tract and other mucosal surfaces. Whole-exome sequencing revealed that the patient inherited missense MALT1 mutations and her lymphocytes exhibited deficits in MALT1 protein and MALT1-dependent signal transduction. MALT1 plays critical roles in T cell receptor signal transduction through at least two different mechanisms: (1) as a signaling adaptor molecule bringing together CARMA-1 and BCL-10 to form the CBM signalosome complex and (2) as a caspase-like protease (paracaspase) cleaving substrates after arginine residues. Studies on Malt1−/− mice have revealed diminished NF-KB activation and weakened T cell immunity whereas mice lacking paracaspase activity but not MALT1 adaptor function are prone to lethal autoimmunity. Altogether, these mouse findings raise questions regarding the nature of our patient’s mutant MALT1 protein and the role it plays in her proinflammatory phenotype. Consequently, we plan to analyze our patient’s MALT1 mutation by investigating the paracaspase activity, signaling, and function of her T cells. Early studies have found that patient CD4 T cells exhibit defects in Th1 and Th17 differentiation and these impairments could be responsible for inefficient immune responses leading to chronic infections. Finally, a better understanding of MALT1 will provide insight into inflammatory disease and prove invaluable in supporting MALT1-targeted therapies to modulate T cells to treat autoimmune diseases.

Proceedings of the Canadian society of allergy and clinical immunology annual scientific meeting 2015

A1 Role of fibrocytes in allergic rhinitis

Marie-Ève Côté, Marie-Ève Boulay, Sophie Plante, Jamila Chakir, Louis-Philippe Boulet

A2 Patterns of aeroallergens sensitization in Northern Alberta

Hanan Ahmed, Maria-Beatriz Ospina, Kyriaki Sideri, Harissios Vliagoftis

A3 Addressing acceptable risk for adolescents with Food-Induced Anaphylaxis (FIA)

Sara F. Johnson, Roberta L. Woodgate

A4 Outcomes of matched related and unrelated bone marrow transplantation after reduced-toxicity conditioning for children suffering from Chronic Granulomatous Disease

Guilhem Cros, Pierre Teira, Sonia Cellot, Henrique Bittencourt, Helene Decaluwe, Marie France Vachon, Michel Duval, Elie Haddad

A5 Outcomes of patients with severe combined immunodeficiency (SCID) prior to and after initiation of newborn screening for SCID in Ontario

Vy H.D. Kim, Anne Pham-Huy, Eyal Grunebaum

A6 Detection of regulatory B cells in the airways of subjects with asthma

John-Paul Oliveria, Stephanie Phan, Mark W. Tenn, Damian Tworek, Steven G. Smith, Adrian J. Baatjes, Caitlin D. Obminski, Caroline E. Munoz, Tara X. Scime, Roma Sehmi, Gail M Gauvreau

A7 Characterization of IgE-expressing B cells in the airways and peripheral blood of allergic asthmatic subjects

John-Paul Oliveria, Stephanie Phan, Mark W. Tenn, Brittany M Salter, Steven G Smith, Caitlin D Obminski, Caroline E Munoz, Abbey Schlatman, Tara X Scime, Rick Watson, Roma Sehmi, Gail M Gauvreau

A8 Pregnancy: could it be a risk factor for primary immunodeficient patients

Roya Sherkat, Razieh Khoshnevisan, Saba Sheikhbahaei

A9 Clinical experience with Octagam: a Canadian retrospective chart review

Stephen Betschel, Richard Warrington, Robert Schellenberg

A10 Kounis syndrome secondary to contrast media with inferior ST elevations and bilateral ischemic stroke

Michael N Fein, Jean-Philippe Pelletier

A11 Honey bee venom immunotherapy ineffective in bumble bee-induced anaphylaxis: case report and review of literature

Manstein Kan, Robert Schellenberg

A12 Delayed immune reconstitution occurring after multiple immune complications of hematological stem cell transplantation for a leaky SCID

Roxane Labrosse, Guilhem Cros, Pierre Teira, Henrique Bittencourt, Helene Decaluwe, Michel Duval, Elie Haddad

A13 Comparison of Three Case Reports of Acquired Angioedema: presentation, management and outcome

Raymond Mak, James Loh, Amin Kanani

A14 Sitagliptin-associated angioedema not related to concurrent use of ARB or ACE inhibitor

Dominik A. Nowak, Paul K. Keith

A15 Sneddon-Wilkinson subcorneal pustular dermatosis associated with an IgA monoclonal gammopathy

Daniel Pannozzo, Dominik A. Nowak, Hermenio C. Lima

A16 Omalizumab can be effective in patients with allergic bronchopulmonary aspergillosis

Diana Pham, Hoang Pham, Gonzalo G. Alvarez, Istvan T. Bencze, Krishna B. Sharma, Mark Smith, Shawn Aaron, Jennifer Block, Tara Keays, Judith Leech, David Schneidermen, Jodi Cameron, Jennifer Forgie, Alicia Ring, John W. O’Quinn, Stephanie Santucci, William H. Yang

A17 Efficacious use of omalizumab in the treatment of cystic fibrosis

Diana Pham, Hoang Pham, Ena Gaudet, Shawn Aaron, Stephanie Santucci, William H. Yang

A18 HAE with normal C1-INH with inconsistent response to C1 esterase inhibitor infusion but reliably responsive to icatibant

Hoang Pham, Stephanie Santucci, William H. Yang

A19 Anaphylaxis reaction to lactase enzyme

Mathew R. Voisin, Rozita Borici-Mazi

A20 Risk of solid tumor malignancies in patients with primary immune deficiency

Kateryna Vostretsova, Donald F. Stark

A21 Is it time to adopt the chromogenic assay for measuring C1 esterase inhibitor function in patients with HAE Type 2?

Elizabeth Yeboah, Paul K. Keith

A22 Emergency department visits for anaphylaxis and allergic reactions

Michelle Martin-Rhee, Cheryl Gula, Clare Cheng, Geoff Paltser

A23 START: Susceptibility To food Allergies in a Registry of Twins

Alizée Dery, Ann Clarke, Kari Nadeau, Laurie Harada, Kimberley Weatherall, Celia Greenwood, Denise Daley, Yuka Asai, Moshe Ben-Shoshan

A24 Qualifying the diagnostic approach employed by allergists when managing patients with self-diagnosed non-celiac gluten sensitivity (NCGS)

Lee Horgan, Teresa Pun

A25 Retrospective analysis on the agreement between skin prick test and serum food specific IgE antibody in adults with suspected food allergy

Ling Ling, Maria B. Ospina, Kyriaki Sideri, Harissios Vliagoftis

A26 Staple food hypersensitivity from infancy to adolescence: a report from the BAMSE cohort

Jennifer L.P. Protudjer, Mirja Vetander, Marianne van Hage, Ola Olén, Magnus Wickman, Anna Bergström

A27 Evaluating the impact of supervised epinephrine autoinjector administration during food challenges on perceived parent confidence

Timothy Teoh, Christopher Mill, Tiffany Wong, Ingrid Baerg, Angela Alexander, Kyla J. Hildebrand, John Dean, Boris Kuzeljevic, Edmond S. Chan

A28 Local immunoglobulin production to Aspergillus fumigatus cystic fibrosis

Jonathan Argeny, Mia Gona-Hoepler, Petra Fucik, Edith Nachbaur, Saskia Gruber, Reto Crameri, Andreas Glaser, Zsolt Szépfalusi, Claudio Rhyner, Thomas Eiwegger

A29 Extract consumption with skin prick test (SPT) devices

Greg. Plunkett, Brad Mire

A30 Evaluation of our cases with nonsteroidal anti-inflammatory drug reactions

Mehtap Yazicioglu, Ceren Can, Gokce Ciplak

A31 Reasons for referral and final diagnoses in a tertiary care pediatric allergy clinic

Victoria E. Cook, Kyla J. Hildebrand, Elodie Portales-Casamar, Christopher Mill, Edmond S. Chan

A32 Internist referral practices for inpatients with self-reported penicillin allergies at a tertiary care teaching hospital

Michael N Fein, Emil P Nashi

A33 Assessing the risk of reactions in children with a negative oral challenge after a subsequent use of amoxicillin

Sofianne Gabrielli, Christopher Mill, Marie-Noel Primeau, Christine Lejtenyi, Elena Netchiporouk, Alizee Dery, Greg Shand, Moshe Ben-Shoshan

A34 Validity of self-reported penicillin allergies

Erica Hoe, Joel Liem

A35 Effectiveness of allergy-test directed elimination diets in eosinophilic esophagitis

Jason K. Ko, David J.T. Huang, Jorge A. Mazza

A36 Allergy testing and dietary management in pediatric eosinophilic esophagitis (EoE): A retrospective review of a tertiary Canadian centre’s experience

Mary McHenry, Anthony Otley,Wade Watson

A37 Visualizing the impact of atopic and allergic skin disease

Dominik A. Nowak, John N. Kraft

A38 Cystic fibrosis with and without nasal polyposis in pediatric patients: a cross-sectional comparative study

Mihaela Paina, Ahmed A. Darwish Hassan, Delia Heroux, Lynn Crawford, Gail Gauvreau, Judah Denburg, Linda Pedder, Paul K. Keith

A39 Evaluation of macrolide antibiotic hypersensitivity: the role of oral challenges in children

Bahar Torabi, Marie-Noel Primeau, Christine Lejtenyi, Elaine Medoff, Jennifer Mill, Moshe Ben-Shoshan

A40 Venom allergy testing: is a graded approach necessary?

Jaclyn A. Quirt, Xia Wen, Jonathan Kim, Angel Jimenez Herrero, Harold L. Kim

A41 The role of oral challenges in evaluating cephalosporin hypersensitivity reactions in children

Magdalena J. Grzyb, Marie-Noël Primeau, Christine Lejtenyi, Elaine Medoff, Jennifer Mill, Moshe Ben-Shoshan

A42 Breastfeeding and infant wheeze, atopy and atopic dermatitis: findings from the Canadian Healthy Infant Longitudinal Development Study

Meghan B. Azad, Zihang Lu, Allan B. Becker, Padmaja Subbarao, Piushkumar J. Mandhane, Stuart E. Turvey, Malcolm R. Sears, the CHILD Study Investigators

A43 IL33 DNA methylation in bronchial epithelial cells is associated to asthma

Anne-Marie Boucher-Lafleur, Valérie Gagné-Ouellet, Éric Jacques, Sophie Plante, Jamila Chakir, Catherine Laprise

A44 NRF2 mediates the antioxidant response to organic dust-induced oxidative stress in bronchial epithelial cells

Michael Chen, Toby McGovern, Mikael Adner, James G. Martin

A45 The effects of perinatal distress, immune biomarkers and mother-infant interaction quality on childhood atopic dermatitis (rash) at 18 months

Nela Cosic, Henry Ntanda, Gerald Giesbrecht, Anita Kozyrskyj, Nicole Letourneau

A46 Examining the immunological mechanisms associated with cow’s milk allergy

Bassel Dawod, Jean Marshall

A47 Tryptase levels in children presenting with anaphylaxis to the Montréal Children’s Hospital

Sarah De Schryver, Michelle Halbrich, Ann Clarke, Sebastian La Vieille, Harley Eisman, Reza Alizadehfar, Lawrence Joseph, Judy Morris, Moshe Ben-Shoshan

A48 Secondhand tobacco smoke exposure in infancy and the development of food hypersensitivity from childhood to adolescence

Laura Y. Feldman, Jesse D. Thacher, Inger Kull, Erik Melén, Göran Pershagen, Magnus Wickman, Jennifer L. P. Protudjer, Anna Bergström

A49 Combined exposure to diesel exhaust and allergen enhances allergic inflammation in the bronchial submucosa of atopic subjects

Ali Hosseini, Tillie L. Hackett, Jeremy Hirota, Kelly McNagny, Susan Wilson, Chris Carlsten

A50 Comparison of skin-prick test measurements by an automated system against the manual method

Saiful Huq, Rishma Chooniedass, Brenda Gerwing, Henry Huang, Diana Lefebvre, Allan Becker

A51 The accurate identification and quantification of urinary biomarkers of asthma and COPD through the use of novel DIL- LC-MS/MS methods

Mona M. Khamis, Hanan Awad, Kevin Allen, Darryl J. Adamko, Anas El-Aneed

A52 Systemic immune pathways associated with the mechanism of Cat-Synthetic Peptide Immuno-Regulatory Epitopes, a novel immunotherapy, in whole blood of cat-allergic people

Young Woong Kim, Daniel R. Gliddon, Casey P. Shannon, Amrit Singh, Pascal L. C. Hickey, Anne K. Ellis, Helen Neighbour, Mark Larche, Scott J. Tebbutt

A53 Reducing the health disparities: online support for children with asthma and allergies from low-income families

Erika Ladouceur, Miriam Stewart, Josh Evans, Jeff Masuda, Nicole Letourneau, Teresa To, Malcolm King

A54 Epigenetic association of PSORS1C1 and asthma in the Saguenay-Lac-Saint-Jean asthma study

Miriam Larouche, Liming Liang, Catherine Laprise

A55 IL-33 induces cytokine and chemokine production in human mast cells

Stephanie A. Legere, Ian D. Haidl, Jean-Francois Legaré, Jean S. Marshall

A56 Reference ranges for lung clearance index from infancy to adolescence for Canadian population

Zihang Lu, Malcolm Sears, Theo J. Moraes, Felix Ratjen, Per Gustafsson, Wendy Lou, Padmaja Subbarao

A57 Kingston Allergy Birth Cohort: cohort profile and mother/child characteristics to age 2

Michelle L. North, Elizabeth Lee, Vanessa Omana, Jenny Thiele, Jeff Brook, Anne K. Ellis

A58 Cow’s milk protein specific IgE, IgA and IgG4 as a predictor of outcome in oral immunotherapy

Tanvir Rahman, Duncan Lejtenyi, Sarah De Schryver, Ryan Fiter, Ciriaco Piccirillo, Moshe Ben-Shoshan, Bruce Mazer

A59 Age of peanut introduction and development of reactions and sensitization to peanut

Elinor Simons, Allan B. Becker, Rishma Chooniedass, Kyla Hildebrand, Edmond S. Chan, Stuart Turvey, Padmaja Subbarao, Malcolm Sears

A60 Multi-omic blood biomarker signatures of the late phase asthmatic response

Amrit Singh, Casey P. Shannon, Young Woong Kim, Mari DeMarco, Kim-Anh Le Cao, Gail M. Gauvreau, J. Mark FitzGerald, Louis-Philippe Boulet, Paul M. O’Byrne, Scott J. Tebbutt

A61 Early life gut microbial alterations in children diagnosed with asthma by three years of age

Leah T. Stiemsma, Marie-Claire Arrieta, Jasmine Cheng, Pedro A. Dimitriu, Lisa Thorson, Sophie Yurist, Boris Kuzeljevic, Diana L. Lefebvre, Padmaja Subbarao, Piush Mandhane, Allan Becker, Malcolm R. Sears, Kelly M. McNagny, Tobias Kollmann, the CHILD Study Investigators, William W. Mohn, B. Brett Finlay, Stuart E. Turvey

A62 The relationship between food sensitization and atopic dermatitis at age 1 year in a Canadian birth cohort

Maxwell M. Tran, Diana L. Lefebvre, Chinthanie F. Ramasundarahettige, Allan B. Becker, Wei Hao Dai, Padmaja Subbarao, Piush J. Mandhane, Stuart E. Turvey, Malcolm R. Sears

A63 Allergen inhalation enhances Toll-like receptor-induced thymic stromal lymphopoietin receptor expression by hematopoietic progenitor cells in mild asthmatics

Damian Tworek, Delia Heroux, Seamus N. O’Byrne, Paul M. O’Byrne, Judah A. Denburg

A64 The Allergic Rhinitis Clinical Investigator Collaborative – replicated eosinophilia on repeated cumulative allergen challenges in nasal lavage samples

Laura Walsh, Mena Soliman, Jenny Thiele, Lisa M. Steacy, Daniel E. Adams, Anne K. Ellis

A65 The CHILD Study: optimizing subject retention in pediatric longitudinal cohort research

Linda Warner, Mary Ann Mauro, Robby Mamonluk, Stuart E. Turvey

A66 Differential expression of C3a and C5a in allergic asthma

ChenXi Yang, Amrit Singh, Casey P. Shannon, Young Woong Kim, Ed M. Conway, Scott J. Tebbutt

Tregs from T1D subjects with a susceptible IL-2R gene SNP, respond aberrantly to IL-2 stimulation. (P4080)

Type 1 diabetes (T1D) results from the destruction of beta cells by autoreactive lymphocytes. Regulatory T cells (Tregs) maintain self-tolerance in part by suppressing the effector functions of self-reactive lymphocytes. Tregs require the cytokine interleukin-2 (IL-2) for survival and maintenance of their suppressive function. IL-2 binds to the high-affinity IL-2 receptor (IL-2R), leading to phosphorylation of signal transducer and activator of transcription 5 (STAT5) and downstream transcription of effector proteins.The IL-2 receptor gene has single nucleotide polymorphisms (SNPs), which are associated with T1D incidence. We hypothesized that T1D subjects with SNPs in the IL-2R gene possess Tregs that respond aberrantly to IL-2 and do not optimally induce signaling in the STAT5 pathway. PBMC from T1D subjects with a homozygous susceptible (GG), heterozygous (AG) and homozygous wild-type (AA) genotype for a SNP located in the rs3118470 locus of the IL-2R gene were stimulated with IL-2. Our results indicate that Tregs from individuals with the homozygous susceptible GG genotype have reduced levels of pSTAT5 compared to those with the AA genotype (p=0.0133). This provides evidence that Tregs from T1D subjects with SNPs in the rs3118470 locus of the IL-2R gene have diminished STAT5 phosphorylation in response to IL-2. This is a potential mechanism of defective Treg function in a genetically identifiable subset of children with T1D.

Robust TLR4-induced gene expression patterns are not an accurate indicator of human immunity

BACKGROUND

Activation of Toll-like receptors (TLRs) is widely accepted as an essential event for defence against infection. Many TLRs utilize a common signalling pathway that relies on activation of the kinase IRAK4 and the transcription factor NFkappaB for the rapid expression of immunity genes.

METHODS

21 K DNA microarray technology was used to evaluate LPS-induced (TLR4) gene responses in blood monocytes from a child with an IRAK4-deficiency. In vitro responsiveness to LPS was confirmed by real-time PCR and ELISA and compared to the clinical predisposition of the child and IRAK4-deficient mice to Gram negative infection.

RESULTS

We demonstrated that the vast majority of LPS-responsive genes in IRAK4-deficient monocytes were greatly suppressed, an observation that is consistent with the described role for IRAK4 as an essential component of TLR4 signalling. The severely impaired response to LPS, however, is inconsistent with a remarkably low incidence of Gram negative infections observed in this child and other children with IRAK4-deficiency. This unpredicted clinical phenotype was validated by demonstrating that IRAK4-deficient mice had a similar resistance to infection with Gram negative S. typhimurium as wildtype mice. A number of immunity genes, such as chemokines, were expressed at normal levels in human IRAK4-deficient monocytes, indicating that particular IRAK4-independent elements within the repertoire of TLR4-induced responses are expressed.

CONCLUSIONS

Sufficient defence to Gram negative immunity does not require IRAK4 or a robust, 'classic' inflammatory and immune response.

Old challenges and new directions in pediatric rheumatology

A symposium was convened April 2, 2005, by the Department of Pediatrics, University of British Columbia, Vancouver, Canada. The event was a tribute to Dr. Ross Petty on his retirement and in recognition of his contributions to the local and international community of pediatric rheumatology. Speakers were past and present fellows, local basic science and adult rheumatology colleagues, and pediatric rheumatologists from the Pacific North West.