Age-Related Food Aversion and Anxiety Represent Primary Patient Barriers to Food Oral Immunotherapy

BACKGROUND

Although oral immunotherapy (OIT) for food allergy is a reasonable treatment option, barriers to this procedure's implementation have not been extensively evaluated from a patient perspective.

OBJECTIVE

We evaluated the barriers patients face during OIT administration, including anxiety and taste aversion, and the role of health care professionals, especially dietitians.

METHODS

A survey in Canada and the United States involved families currently enrolled in food OIT programs.

RESULTS

Of responses from 379 participants, fear of reaction was the most common barrier to OIT initiation, with 45.6% reporting it being a "very significant" barrier with other fears reported. However, taste aversion represented the prominent obstacle to continuation. Taste aversion was associated with a slower buildup (P = .02) and a reduction in dose (P = .002). Taste aversion was a strongly age-dependent barrier for initiation (P < .001) and continuation (P < .002), with older children over 6 years of age reporting it as a very significant barrier (P < .001). Boredom was reported as a concern for specific allergens such as peanut, egg, sesame, and hazelnuts (P < .05), emphasizing the need for diverse food options. Notably, 59.9% of respondents mixed OIT foods with sweet items. Despite these dietary concerns, dietitians were underutilized, with only 9.5% of respondents having seen a dietitian and the majority finding dietitian support helpful with greater certainty about the exact dose (P < .001).

CONCLUSIONS

Taste aversion and anxiety represent primary patient-related barriers to OIT. Taste aversion was highly age dependent, with older patients being more affected. Dietitians and psychology support were underutilized, representing a critical target to improve adherence and OIT success.

Real-world safety and effectiveness analysis of low-dose preschool sesame oral immunotherapy

Background

Previous studies support the effectiveness of sesame oral immunotherapy (S-OIT) in patients >4 years old using maintenance doses of 1200 mg protein. However, tahini is often not palatable to children, and high-maintenance doses may not be possible for preschoolers.

Objective

We studied the safety and effectiveness outcomes of preschoolers with sesame allergy who underwent low-dose S-OIT of 200 mg protein.

Methods

Preschoolers with sesame allergy, with a history of objective reaction to sesame, and with either a positive skin prick test result (wheal diameter ≥3 mm) or sesame-specific IgE level ≥0.35 kU/L were included. Doses were escalated every 2 to 4 weeks until the maintenance dose of 200 mg of sesame protein was reached. The maintenance dose was continued daily for 1 year, followed by exit oral food challenge (OFC). Primary safety outcomes included allergic reactions grade 2 or higher and the need for epinephrine therapy during buildup. The primary effectiveness outcome was proportion of patients tolerating a minimum of 2000 mg sesame protein at exit OFC.

Results

Twenty-eight preschoolers (median age, 33.5 months) were enrolled to receive S-OIT. During the buildup phase, 9 subjects (32.1%) had no reaction, and 8 (28.6%) and 11 (39.3%) had grade 1 and 2 reactions, respectively. One patient (3.57%) received epinephrine for a grade 2 reaction. Twenty-one (91.3%) of 23 eligible subjects underwent exit OFC; 18 (85.7%) of these 21 patients successfully completed exit OFC. One (4.8%) and 2 (9.5%) subjects had grade 1 and 2 reactions, respectively, during OFC.

Conclusions

A lower and age-appropriate maintenance dose is safe and effective in desensitizing preschoolers with sesame allergy.

Using the canadian egg ladder in children with food protein-induced enterocolitis syndrome: a case series

BACKGROUND

Current management of food protein-induced enterocolitis syndrome (FPIES) involves strict avoidance of the offending food for 12-18 months, followed by oral food challenge (OFC) under physician supervision. OFCs are resource-intensive and there is a lack of a universal standardized protocol for FPIES. Prolonged avoidance may increase the risk of IgE-mediated allergy, particularly in atopic patients. Food ladders have shown success in promoting accelerated tolerance in patients with IgE-mediated allergy. Our case series evaluated the safety of use of the Canadian Egg Ladder in patients with mild-to-moderate FPIES to egg.

METHODS

From May 2020 to November 2021, patients with mild-to-moderate FPIES to egg, defined as no history of lethargy or intravenous fluid administration, were started on the Canadian Egg Ladder. Instructions for advancing up the ladder were identical to using the Canadian Egg Ladder in patients with IgE-mediated allergy. Patients were followed every 3-6 months, at which time information was collected regarding progression up the ladder, symptoms while on treatment and interventions required. Treating allergists completed a survey to capture baseline demographic characteristics and prior tolerance to egg. Descriptive statistics were analyzed using MS Excel.

RESULTS

Twenty-one patients with mild-to-moderate FPIES were started on the Canadian Egg Ladder. Median age at initiation of the ladder was 10 months (IQR, 9-11). Nineteen (90.5%) patients completed the ladder, tolerating a serving size amount of cooked egg, over a median duration of 7 month (IQR, 4-9 months). Four patients (19.0%) had mild symptoms including vomiting (9.5%), pallor (9.5%), belching (4.8%), irritability (4.8%) and small spit up (4.8%). In three of the four patients, symptoms were the result of accidental exposure to a higher step of the ladder. There were no reports of lethargy. No patients required health care presentation or intravenous fluid administration. No patients discontinued the ladder.

CONCLUSIONS

The Canadian Egg Ladder can safely guide the dietary advancement of egg-containing foods in patients with mild-to-moderate FPIES to egg, without the need for prolonged avoidance and resource-intensive OFCs.

Risk factors associated with safety of preschool peanut oral immunotherapy

Background

An understanding of how patient characteristics such as age, baseline peanut-specific IgE, and atopic comorbidities may influence potential safety outcomes during peanut oral immunotherapy (P-OIT) could aid in shared decision making between clinicians and patient families.

Objective

This study explored the relationship between baseline patient characteristics and reactions during P-OIT using a large sample size to better understand potential risk factors influencing P-OIT safety.

Methods

Data were obtained from the Food Allergy Immunotherapy (FAIT) registry, which collects real-world OIT data from community and academic allergy clinics across Canada. Multivariable logistic regression modeling was performed to examine the relationship between baseline patient characteristics and reactions during P-OIT. Multiple imputation was applied to reduce potential bias caused by missingness and to maximize the use of available information to preserve statistical power.

Results

Between April 2017 and June 2021, a total of 653 eligible patients initiated P-OIT. Multivariable regression analysis showed pre-OIT grade 2+ initial reaction (odds ratio [OR] = 1.33, 95% confidence interval [CI] 1.10, 1.61), allergic rhinitis (OR = 1.60, 95% CI 1.08, 2.38), older age (OR = 1.01, 95% CI 1.00, 1.02), and higher baseline peanut-specific IgE (OR = 1.02, 95% CI 1.02, 1.03) were associated with grade 2+ reaction during P-OIT after adjusting for potential risk factors.

Conclusion

Our study identified several clinically important risk factors for grade 2+ reactions during P-OIT: pre-OIT grade 2+ initial reaction, allergic rhinitis, older age, and higher baseline peanut-specific IgE. These results highlight the need for individualized risk stratification for OIT.

Real-World Safety Analysis of Preschool Tree Nut Oral Immunotherapy

BACKGROUND

Our group previously described preschool peanut oral immunotherapy (OIT) in a real-world, multicenter setting, suggesting that this therapy is safe for most preschoolers.

OBJECTIVE

To examine the safety and tolerability of tree nut (TN) OIT in preschoolers in the real world.

METHODS

As part of a Canada-wide quality improvement project, TN-OIT (cashew/pistachio, walnut/pecan, hazelnut, almond, and macadamia nut) was performed in preschoolers who had (1) a skin prick test wheal diameter greater than or equal to 3 mm or a specific IgE level greater than or equal to 0.35 kU/L and a convincing objective IgE-mediated reaction or (2) no ingestion history and a specific IgE level greater than or equal to 5 kU/L. Dose escalations were performed every 2 to 4 weeks till a maintenance dose of 300 mg of TN protein was reached. Symptoms were recorded and classified using the modified World Allergy Organization Subcutaneous Immunotherapy Reaction Grading System (1, mildest; 5, fatal).

RESULTS

Of the 92 patients who started TN-OIT from 2018 to 2021, 79 (85.9%) underwent single-food TN-OIT and 13 (14.1%) underwent multifood TN-OIT to 2 (10.8%) or 3 (3.3%) TNs. Eighty-nine (96.7%) patients reached maintenance, and 4 (4.3%) dropped out. Sixty-five (70.7%) patients experienced reactions during buildup: 35 (38.0%) grade 1 reactions, 30 (32.6%) grade 2 reactions, no grade 3 or 4 reactions, and 2 (2.17%) received epinephrine.

CONCLUSIONS

Preschool TN-OIT in a real-world, multicenter setting appears safe and tolerable, with results comparable with our previously reported peanut OIT findings.

The Case for Prompt Salvage Infant Peanut Oral Immunotherapy Following Failed Primary Prevention

Recent guideline recommendations have shifted from recommending prolonged avoidance of allergenic foods in the first 3 years of life to a primary prevention approach involving the deliberate early introduction to infants at risk of developing food allergy. Despite this, some infants, especially those with severe eczema who are at highest risk for developing peanut allergy, fail to receive the preventative benefits of early peanut introduction due to hesitancy and other factors. Difficulty adhering to regular ingestion after introduction further reduces the effectiveness of primary prevention. As emerging real-world evidence has demonstrated that performing peanut oral immunotherapy (OIT) among infants is effective and safe, peanut OIT could be a treatment option for infants with peanut allergy. This review discusses the benefits, risks, and barriers to offering peanut OIT to infants who fail primary prevention strategies. We propose the novel concept that infants with peanut allergy be offered peanut OIT as soon as possible after failed peanut introduction through a shared decision-making process with the family, where there is a preference for active management rather than avoidance.

Home-Based Peanut Oral Immunotherapy for Low-Risk Peanut-Allergic Preschoolers During the COVID-19 Pandemic and Beyond

The coronavirus disease 2019 (COVID-19) pandemic has led to the deprioritization of non-emergency services, such as oral food challenges and the initiation of oral immunotherapy (OIT) for food-allergic children. Recent studies have suggested that home-based peanut OIT could be a safe and effective option for low-risk peanut-allergic children. In the period between September 1, 2020, and January 31, 2021, nine preschoolers with a history of mild allergic reactions to peanut underwent home-based peanut OIT. Eight of them (88.9%) completed the build-up phase at home in 11–28 weeks, tolerating a daily maintenance dose of 320 mg peanut protein. During the build-up, six patients (75.0%) reported urticaria, three (33.3%) reported gastrointestinal tract symptoms, and one (14.3%) reported oral pruritis. None of the patients developed anaphylaxis, required epinephrine, or attended emergency services related to OIT. One or two virtual follow-up visits were completed per patient during the build-up phase. Our case series shows that home-based OIT could be offered to the low-risk preschoolers during the COVID-19 pandemic when non-emergency services are limited and could be considered beyond the pandemic, especially for the families living in the rural or remote areas that may otherwise be unable to access OIT.

Allergic reactions to emerging food allergens in Canadian children

Most Canadian food allergy data has focused on Health Canada’s priority food allergens. This study describes which non-priority (emerging) food allergens were most commonly reported by Canadian parents and categorized/confirmed by allergists. A secondary aim was to describe severity of allergic reactions to emerging allergens. Parents reported allergic reactions to emerging food allergens experienced by their child (< 18 years) which occurred in the past 12 months, and allergists categorized/confirmed them according to likelihood of IgE-mediated food allergy. Of 68 eligible patients completing the survey, the most commonly reported emerging allergens were fruits/vegetables (58.8%), seeds (22.1%), legumes (19.1%) and other (11.8%). Median allergist ranking for legumes was ‘probable’ IgE-mediated food allergy, ‘possible’ for seeds and fruits/vegetables, and ‘unlikely’ for other. Median reaction severity was mild for legumes, and moderate for seeds, fruits/vegetables, and other. Our study highlights that non-priority food allergens, namely legumes and seeds, can lead to probable/likely allergic reactions in Canadian children. These food allergens are increasing in popularity in the Canadian diet, which could lead to increasing reports of allergic reactions. More research is needed to confirm reports of reactions to emerging allergens, and to document their inclusion as ingredients in packaged foods.

First Real-World Effectiveness Analysis of Preschool Peanut Oral Immunotherapy

BACKGROUND

We previously described safety of preschool peanut oral immunotherapy (P-OIT) in a real-world setting; 0.4% of patients experienced a severe reaction, and 4.1% received epinephrine, during build-up.

OBJECTIVE

To determine the effectiveness of preschool P-OIT after 1 year of maintenance.

METHODS

Preschoolers (9-70 months) with at least 1 objective reaction to peanut (during baseline oral food challenge (OFC) or P-OIT build-up) received a follow-up OFC to cumulative 4000 mg protein after 1 year on 300 mg peanut daily maintenance. Effectiveness of desensitization was defined as proportion of patients with a negative follow-up OFC. Symptoms and treatment at follow-up OFC were recorded.

RESULTS

Of the 117 patients who successfully completed 1 year of P-OIT and subsequently underwent a cumulative 4000-mg follow-up OFC, 92 (78.6%) had a negative OFC and 115 (98.3%) tolerated a cumulative dose of greater than or equal to 1000 mg. For the 25 (21.4%) who reacted, their threshold increased by 3376 mg (95% CI, 2884-3868) from baseline to follow-up; 17 (14.5%) patients experienced grade 1 reactions, 7 (6.00%) grade 2, and 1 (0.85%) grade 3. Two patients (1.71%) received epinephrine associated with P-OIT, and 1 (0.85%) went to the emergency department.

CONCLUSIONS

Our data demonstrate that real-world preschool P-OIT is effective after 1 year of maintenance for those who received a follow-up OFC. For those who reacted, their threshold increased sufficiently to protect against accidental exposures. P-OIT should be considered for preschoolers as an alternative to current recommendations to avoid peanut.

First Real-World Safety Analysis of Preschool Peanut Oral Immunotherapy

BACKGROUND

In 2017, a clinical trial of 37 subjects demonstrated that preschool peanut oral immunotherapy (P-OIT) was safe, with predominantly mild symptoms reported and only 1 moderate reaction requiring epinephrine.

OBJECTIVES

We sought to examine whether these findings would be applicable in a real-world setting.

METHODS

As part of a Canada-wide quality improvement project, community and academic allergists administered P-OIT to preschool-age children who had (1) skin prick test wheal diameter greater than or equal to 3 mm or specific IgE level greater than or equal to 0.35 kU/L and history of reaction and/or positive baseline oral food challenge, or (2) no ingestion history and specific IgE level greater than or equal to 5 kU/L. Over 16 to 22 weeks, patients had biweekly clinic visits for updosing, and consumed the dose daily at home between visits. Target maintenance dose was 300 mg peanut protein. Symptoms were classified using a modified World Allergy Organization Subcutaneous Immunotherapy Reaction Grading System (1 mildest, 5 fatal).

RESULTS

Of 270 patients who started P-OIT in the period 2017 to 2018, 243 reached maintenance, and 27 dropped out (10.0%); 67.8% of patients experienced reactions during buildup: 36.3% grade 1, 31.1% grade 2, and 0.40% grade 4. Eleven patients (4.10%) received epinephrine (10 patients received 1 dose, 1 patient received epinephrine on 2 separate days), representing 2.23% of reactions (12 of 538) and 0.029% of doses (12 of 41,020).

CONCLUSIONS

We are the first group to describe preschool P-OIT in a real-world multicenter setting. The treatment appears to be safe for the vast majority of patients because symptoms were generally mild and very few reactions received epinephrine; however, life-threatening reactions in a minority of patients (0.4%) can still occur.

Compensatory axon sprouting for very slow axonal die-back in a transgenic model of spinal muscular atrophy type III

KEY POINTS

Smn^+/- transgenic mouse is a model of the mildest form of spinal muscular atrophy. Although there is a loss of spinal motoneurons in 11-month-old animals, muscular force is maintained. This maintained muscular force is mediated by reinnervation of the denervated fibres by surviving motoneurons. The spinal motoneurons in these animals do not show an increased susceptibility to death after nerve injury and they retain their regenerative capacity. We conclude that the hypothesized immaturity of the neuromuscular system in this model cannot explain the loss of motoneurons by systematic die-back.

ABSTRACT

Spinal muscular atrophy (SMA) is a common autosomal recessive disorder in humans and is the leading genetic cause of infantile death. Patients lack the SMN1 gene with the severity of the disease depending on the number of copies of the highly homologous SMN2 gene. Although motoneuron death in the Smn^+/- transgenic mouse model of the mildest form of SMA, SMA type III, has been reported, we have used retrograde tracing of sciatic and femoral motoneurons in the hindlimb with recording of muscle and motor unit isometric forces to count the number of motoneurons with intact neuromuscular connections. Thereby, we investigated whether incomplete maturation of the neuromuscular system induced by survival motoneuron protein (SMN) defects is responsible for die-back of axons relative to survival of motoneurons. First, a reduction of ∼30% of backlabelled motoneurons began relatively late, at 11 months of age, with a significant loss of 19% at 7 months. Motor axon die-back was affirmed by motor unit number estimation. Loss of functional motor units was fully compensated by axonal sprouting to retain normal contractile force in four hindlimb muscles (three fast-twitch and one slow-twitch) innervated by branches of the sciatic nerve. Second, our evaluation of whether axotomy of motoneurons in the adult Smn^+/- transgenic mouse increases their susceptibility to cell death demonstrated that all the motoneurons survived and they sustained their capacity to regenerate their nerve fibres. It is concluded the systematic die-back of motoneurons that innervate both fast- and slow-twitch muscle fibres is not related to immaturity of the neuromuscular system in SMA.

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

A quantitative model of DNA fragments generated by ionizing radiation, and possible experimental applications

We derive an equation for observed frequencies of DNA fragments as a function of size. In this derivation, we consider an experimental system where fragments are generated by random, independent double-strand breaks on chromosomes (or other large DNA molecules) and then separated by size on agarose gels. When visualizing these fragments using Southern hybridization techniques (employing a site-specific probe), we predict an intensity distribution that has unusual properties. In particular, peaks in the fragment size distribution depend not only on standard breakage parameters, but also on the location of the hybridization site. Our model is consistent with experimental and theoretical results reported elsewhere, where measurements of peaks are used for the physical mapping of genes. Further, we propose that similar experiments might be suitable for precise measurements of the parameters of double-strand breakage (as an alternative to neutral filter elutions and neutral sucrose gradients) and for testing the assumption of random, independent breakage for different types of radiation.

Use of a ring chromosome and pulsed-field gels to study interhomolog recombination, double-strand DNA breaks and sister-chromatid exchange in yeast

We describe a system that uses pulsed-field gels for the physical detection of recombinant DNA molecules, double-strand DNA breaks (DSB) and sister-chromatid exchange in the yeast Saccharomyces cerevisiae. The system makes use of a circular variant of chromosome III (Chr. III). Meiotic recombination between this ring chromosome and a linear homolog produces new molecules of sizes distinguishable on gels from either parental molecule. We demonstrate that these recombinant molecules are not present either in strains with two linear Chr. III molecules or in rad50 mutants, which are defective in meiotic recombination. In conjunction with the molecular endpoints, we present data on the timing of commitment to meiotic recombination scored genetically. We have used x-rays to linearize circular Chr. III, both to develop a sensitive method for measuring frequency of DSB and as a means of detecting double-sized circles originating in part from sister-chromatid exchange, which we find to be frequent during meiosis.

Analysis of DNA double strand breakage and repair using orthogonal field alternation gel electrophoresis

Orthogonal field alternation gel electrophoresis (OFAGE) allows separation of DNA molecules in the size range of 200 kb to 3000 kb. These sizes encompass the chromosome sizes of the genome of Saccharomyces cerevisiae. Using this technique, we have found that yeast cells exposed to X-rays generate a smear of DNA fragments corresponding to the products of random, independent double strand breaks, and that the bands corresponding to unbroken chromosomes decrease in intensity in direct proportion to chromosome size. If exposed wild type cells are permitted time to repair (5 h at 30 degrees C on YEPD), the fragments partially disappear and the chromosome bands reappear, although at less than normal intensity. In certain radiation-sensitive mutants (rad51, rad52 and rad54), the fragment smear appears following X-ray exposure but no repair of broken chromosomes occurs. In fact, loss of the fragments occurs; this could appear as partial repair using other procedures.