Faculty Bibliography

Oral food challenges are an integral part of an allergist's practice and are used to evaluate the presence or absence of allergic reactivity to foods. A work group within the Adverse Reactions to Foods Committee of the American Academy of Allergy, Asthma & Immunology was formed to update a previously published oral food challenge report. The intention of this document was to supplement the previous publication with additional focus on safety, treatment of IgE-mediated allergic reactions, guidance for challenges in infants and adults, psychosocial considerations for children and families participating in an oral food challenge, specific guidance for baked milk or baked egg challenges, masking agents and validated blinding recipes for common food allergens, and recommendations for conducting and interpreting challenges in patients with suspected food protein-induced enterocolitis syndrome. Tables and figures within the report and an extensive online appendix detail age-specific portion sizes, appropriate timing for antihistamine discontinuation, serum and skin test result interpretation, written consents, and instructional handouts that may be used in clinical practice.

BACKGROUND:Sesame is an allergen of increasing importance. OBJECTIVE:We sought to characterize the outcomes of oral food challenges (OFCs) to sesame and evaluate the diagnostic accuracy of skin prick testing (SPT), sesame, and Ses i 1-specific IgE (sIgE). METHODS:We reviewed sesame OFCs performed at the Mount Sinai pediatric allergy clinic between January 2010 and April 2018. We assessed the accuracy of diagnostic tests by calculating the area under the curve (AUC) of the receiver operating characteristic curves. The association between OFC outcome and sesame sensitization was analyzed using a logistic regression, which was then used to estimate the 95% positive predictive value (PPV) of these tests. RESULTS:We identified 341 patients (69% male, mean age 7.7 years) who underwent sesame OFC. Among 106 (31%) positive OFCs, the median cumulative eliciting dose was 500 mg sesame protein (1/2 teaspoon tahini). Sesame SPT wheal ≥6 mm had sensitivity 54.1% and specificity 87.8%; AUC 0.756 (95% confidence interval [CI], 0.699-0.814). SPT wheal size ≥14 mm had 95% PPV. Sesame-sIgE level did not correlate with OFC outcome. Ses i-sIgE levels were analyzed in 30 patients using the Immuno Solid-phase Allergen Chip (ISAC) microarray and were significantly associated with OFC outcome (AUC: 0.715 [95% CI, 0.541-0.890]). Ses i 1-sIgE ≥0.3 ISAC Standardized Units had sensitivity 58.3% and specificity 83.3%. CONCLUSIONS:This is the largest study of sesame allergy to date. Sesame SPT is a more accurate predictor of sesame allergy compared with sesame sIgE. Ses i 1-sIgE appears promising but requires further study regarding diagnostic accuracy.

Eosinophilic esophagitis (EoE) is an atopic disease characterized by eosinophilic inflammation in the esophagus.

Professor Hugh A. Sampson, MD is a Canadian- born American clinician and translational researcher, whose evidence-based approach validated food allergy as a legitimate allergic disorder. He single-handedly transformed the management of patients with food allergies and initiated investigations that led to novel diagnostic tests and therapies giving hope to millions of individuals and their families worldwide. Hugh Sampson's immense impact on the rapidly developing field of food allergy makes him a true legend in allergy/immunology.

It is well-established that food proteins, such as egg, soya, cow's milk and wheat, are detectable in breastmilk for many hours or days after ingestion. Exposure to these proteins is important to the process of developing tolerance but can also sometimes elicit IgE-mediated and non-IgE-mediated allergic symptoms in breastfed infants. Non-IgE-mediated allergy, outside of food protein-induced allergic proctocolitis and eosinophilic oesophagitis, is not well understood, leading to variations in the diagnosis and management thereof. A primary objective of the European Academy for Allergy and Clinical Immunology is to support breastfeeding in all infants, including those with food allergies. A Task Force was established, to explore the clinical spectrum of non-IgE-mediated allergies, and part of its objectives was to establish diagnosis and management of non-IgE-mediated allergies in breastfed infants. Eight questions were formulated using the Patient, Intervention, Comparison, Outcome (PICO) system and Scottish Intercollegiate Guideline Network (SIGN) criteria for data inclusion, and consensus was achieved on practice points through the Delphi method. This publication aims to provide a comprehensive overview on this topic with practice points for healthcare professionals.

Exopalaemon modestus (EM) is a shrimp delicacy that could cause food allergy, the major allergen of EM is Exo m 1. The amino acid (AA) sequence, IgE-binding epitopes and allergenic peptides in gastrointestinal (GI) digests of Exo m 1, and their effects on basophil function were investigated. Exo m 1 has an AA-sequence of high similarity with other shrimp tropomyosins, while not 100% matching. The IgE-binding epitopes of Exo m 1 are epitope 1 (43-59, VHNLQKRMQQLENDLDS), epitope 2 (85-105, VAALNRRIQLLEEDLERSEER), epitope 3 (131-164, ENRSLSDEERMDALENQLKEARFLAEEADRKYDE), epitope 4 (187-201, ESKIVELEEELRVVG) and epitope 5 (243-280, ERSVQKLQKEVDRLEDELVNEKEKYKSITDELDQTFSE). Among the thirty-three peptides of Exo m 1 identified in GI digests, two were highly recognized by IgE, twenty-four moderately or weakly bound IgE, and seven had no IgE-reactivities. These IgE-binding epitopes and GI digestion induced-allergenic peptides could activate basophil degranulation, and CD63 and CD203c expression, they could be potential peptide-based immunotherapy for shrimp allergic individuals.

Food protein-induced enterocolitis syndrome (FPIES) is a non-IgE-mediated gastrointestinal food allergic disorder that has gained a major interest the past decade. FPIES prevalence, which still needs to be accurately determine in different populations, appears to be higher than previously thought (ie up to 0.7% in infants in the 1st year of life). FPIES to seafood in adults is also increasingly reported; limited data suggest that adult FPIES is most commonly triggered by shellfish, tends to affect females more than men, is characterized by a significant delay in diagnosis and a prolonged course. The first international consensus guidelines on diagnosis and management of FPIES have been published in 2017, proposing new diagnostic criteria as well as new criteria for a positive oral food challenge. However, there is a need to develop new biomarkers to improve the diagnosis and management of FPIES patients, and this requires a better understanding of the pathophysiology. Recently, the role of T cells has been questioned and a major role of innate immune cells has been suggested in acute FPIES. Regarding the treatment of acute FPIES reaction, ondansetron has emerged as an adjunct to intravenous rehydration in moderate-severe reactions and as a first-line treatment in mild reactions. Important information regarding the nutritional management of FPIES patients that might be complex has also been provided in the international guidelines. In this review, we discuss recent advances regarding all those different aspects.