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Summary Background Despite progress in single food oral immunotherapy, there is little evidence concerning the safety and efficacy of treating individuals with multiple food (multifood) allergies. We did a pilot study testing whether anti-IgE (omalizumab) combined with multifood oral immunotherapy benefited multifood allergic patients. Methods We did a blinded, phase 2 clinical trial at Stanford University. We enrolled participants, aged 4–15 years, with multifood allergies validated by double-blind, placebo-controlled food challenges to their offending foods. Inclusion criteria included a positive skin prick test of 6 mm or more (wheal diameter, above the negative control), a food-specific serum IgE concentration of more than 4 kU/L for each food, or both, and a positive double-blind, placebo-controlled food challenge at 500 mg or less of food protein. Exclusion criteria included eosinophilic oesophagitis and severe asthma. Participants were randomised (3:1) with a block size of four, to receive multifood oral immunotherapy to two to five foods, together with omalizumab (n=36) or placebo (n=12). 12 individuals who fulfilled the same inclusion and exclusion criteria were included as controls. These individuals were not randomised and received neither omalizumab nor oral immunotherapy. Omalizumab or placebo was administered subcutaneously for 16 weeks, with oral immunotherapy starting at week 8, and was stopped 20 weeks before the exit double-blind, placebo-controlled food challenge at week 36. The primary endpoint was the proportion of participants who passed double-blind, placebo-controlled food challenges to at least two of their offending foods. This completed trial is registered with ClinicalTrials.gov, number NCT02643862. Findings Between March 25, 2015, and Aug 18, 2016, 165 participants were assessed for eligibility, of whom 84 did not meet the inclusion criteria and 21 declined to participate. We enrolled and randomised 48 eligible participants and the remaining 12 patients were included as nonrandomised, untreated controls. At week 36, a significantly greater proportion of the omalizumab-treated (30 [83%] of 36) versus placebo (four [33%] of 12) participants passed double-blind, placebo-controlled food challenges to 2 g protein for two or more of their offending foods (odds ratio 10·0, 95% CI 1·8–58·3, p=0·0044). All participants completed the study. There were no serious or severe (grade 3 or worse) adverse events. Participants in the omalizumab group had a significantly lower median per-participant percentage of oral immunotherapy doses associated with any adverse events (27% vs 68%; p=0·0082). The most common adverse events in both groups were gastrointestinal events. Interpretation In multifood allergic patients, omalizumab improves the efficacy of multifood oral immunotherapy and enables safe and rapid desensitisation. Funding US National Institutes of Health (NIH).

Background A number of clinical studies focused on treating a single food allergy through oral immunotherapy (OIT) with adjunctive omalizumab treatment have been published. We previously demonstrated safety and tolerability of a rapid OIT protocol using omalizumab in a phase 1 study to achieve desensitization to multiple (up to 5) food allergens in parallel, rapidly (7–36 weeks; median = 18 weeks). In the current long-term, observational study, we followed 34 food allergic participants for over 5 years, who had originally undergone the phase 1 rapid OIT protocol. Methods After reaching the maintenance dose of 2 g protein for each of their respective food allergens as a part of the phase 1 study, the long-term maintenance dose was reduced for some participants based on a pragmatic team-based decision. Participants were followed up to 62 months through standard oral food challenges (OFCs), skin prick tests, and blood tests. Results Each participant passed the 2 g OFC to each of their offending food allergens (up to 5 food allergens in total) at the end of the long-term follow-up (LTFU) study. Conclusion Our data demonstrate the feasibility of long-term maintenance dosing of a food allergen without compromising the desensitized status conferred through rapid-OIT. Trial registration Registry: Clinicaltrials.gov. Registration numbers: NCT01510626 (original study), NCT03234764 (LTFU study). Date of registration: November 29, 2011 (original study); July 26, 2017 (LTFU study, retrospectively registered)

BackgroundDespite its high prevalence, relatively little is known about the characteristics of patients with multiple tree-nut allergies.MethodsPatients (n=60, aged 4-15 years), recruited for a multiple food (tree nuts, peanut, milk, egg, soy, sesame, and wheat) oral immunotherapy (OIT) study, filled a questionnaire on their initial allergy evaluation. Medical records were reviewed. At OIT enrollment (median interval, 7.5 years), patients underwent oral food challenges (OFCs) to foods still eliminated.ResultsThere was significantly less evidence for eliminating tree nuts compared with other foods, as reflected by a lower rate of acute reaction to the offending food, either as the trigger for initial allergy evaluation (5.9% for tree-nuts vs. 20-40% for other foods, respectively P

BACKGROUND: Oral immunotherapy (OIT) can lead to desensitization to food allergens, but patients can experience treatment-related symptoms of allergic reactions that cause anxiety and treatment dropout. Interventions to improve OIT for patients are needed. OBJECTIVE: To determine whether fostering the mindset that non-life-threatening symptoms during OIT can signal desensitization improves treatment experience and outcomes. METHODS: In a randomized, blinded, controlled phase II study, 50 children/adolescents (28% girls, aged 7–17, M=10.82, SD=3.01) completed six-month OIT for peanut allergies. Patients and their parent(s) had monthly clinic visits at the Sean N. Parker Center for Allergy & Asthma Research between 1/5/2017–8/3/2017. All families received identical symptom management training. In a 1:1 approach, 24 patients and their families were informed that non-life-threatening symptoms during OIT were unfortunate side effects of treatment, and 26 patients and their families were informed that non-life-threatening symptoms could signal desensitization. Families participated in activities to reinforce these symptom mindsets. RESULTS: Compared to families informed that symptoms are side effects, families informed that symptoms can signal desensitization were less anxious (B=−0.46, 95% CI (−0.76 to −0.16), p=0.003), less likely to contact staff about symptoms (5/24[9.4%] vs. 27/154[17.5%] instances, p=0.036), experienced fewer non-life-threatening symptoms as doses increased (B(Interaction)=−0.54(−0.83 to −0.27), p

The prevalence of food allergies has been on the increase over the last 2 decades. Diagnosing food allergies can be complicated, as there are multiple types that have distinct clinical and immunologic features. Food allergies are broadly classified into immunoglobulin E (IgE)-mediated, non-IgE-mediated, or mixed food allergic reactions. This review focuses on the clinical manifestations of the different categories of food allergies and the different tests available to guide the clinician toward an accurate diagnosis.

Background Clinical trials using oral immunotherapy (OIT) for the treatment of food allergies have shown promising results. We previously demonstrated the feasibility of desensitization for up to 5 food allergens simultaneously through OIT. In this observational study, we report the findings of long-term follow-up (LTFU) of the participants treated through a single site OIT phase 1 trial. Methods The participants (n = 46) were followed up to 72 months since the time they reached 2 g maintenance dose per food in the initial phase 1 trial. During the long-term maintenance dosing, participants continued or reduced the initial maintenance dose of food allergen protein to high (median 2 g protein) vs. low (median 300 mg protein). Participant follow-up included clinical monitoring, standardized OFCs, and in some cases, skin prick tests and measurement of allergen-specific IgE and IgG4. Results Irrespective of the high vs. low long-term maintenance dose during LTFU, all participants were able to ingest 2 g protein of each food allergen protein during OFCs performed at the end of our LTFU. Conclusion Our LTFU cohort of food OIT participants from a single site, phase 1 OIT study, supports the feasibility of sustained desensitization through long-term maintenance dosing. Trial registration Registry: Clinicaltrial.gov. Registration numbers: NCT01490177 (original study); NCT03234764 (LTFU study). Date of registration: November 29, 2011 (original study); July 26, 2017 (LTFU study, registered)

Background Thirty percent of children with food allergies have multiple simultaneous allergies; however, the features of these multiple allergies are not well characterized serologically or clinically. Objective We comprehensively evaluated 60 multifood-allergic patients by measuring serum IgE to key allergen components, evaluating clinical histories and medication use, performing skin tests, and conducting double-blind, placebo-controlled food challenges (DBPCFCs). Methods Sixty participants with multiple food allergies were characterized by clinical history, DBPCFCs, total IgE, specific IgE, and component-resolved diagnostics (IgE and IgG4) data. The food allergens tested were almond, egg, milk, sesame, peanut, pecan, walnut, hazelnut, cashew, pistachio, soy, and wheat. Results Our data demonstrate that of the reactions observed during a graded DBPCFC, gastrointestinal reactions occurred more often in boys than in girls, as well as in individuals with high levels of IgE to 2S albumins from cashew, walnut, and hazelnut. Certain food allergies often occurred concomitantly in individuals (ie, cashew/pistachio and walnut/pecan/hazelnut). IgE testing to components further corroborated serological relationships between and among these clustered food allergies. Conclusions Associations of certain food allergies were shown by DBPCFC outcomes as well as by correlations in IgE reactivity to structurally related food allergen components. Each of these criteria independently demonstrated a significant association between allergies to cashew and pistachio, as well as among allergies to walnut, pecan, and hazelnut.

Background Peanut allergy (PA) is a life-threatening condition that lacks regulator-approved treatment. Regulatory T type 1 (T R 1) cells are potent suppressors of immune responses and can be induced in vivo upon repeated antigen exposure or in vitro by using tolerogenic dendritic cells. Whether oral immunotherapy (OIT) leads to antigen-specific T R 1 cell induction has not been established. Objectives We sought to determine whether peanut-specific T R 1 cells can be generated in vitro from peripheral blood of patients with PA at baseline or during OIT and whether they are functional compared with peanut-specific T R 1 cells induced from healthy control (HC) subjects. Methods Tolerogenic dendritic cells were differentiated in the presence of IL-10 from PBMCs of patients with PA and HC subjects pulsed with the main peanut allergens of Arachis hypogaea , Ara h 1 and 2, and used as antigen-presenting cells for autologous CD4 + T cells (CD4 + T cells coincubated with tolerogenic dendritic cells pulsed with the main peanut allergens [pea-T10 cells]). Pea-T10 cells were characterized by the presence of CD49b + lymphocyte-activation gene 3 (LAG3) + T R 1 cells, antigen-specific proliferative responses, and cytokine production. Results CD49b + LAG3 + T R 1 cells were induced in pea-T10 cells at comparable percentages from HC subjects and patients with PA. Despite their antigen specificity, pea-T10 cells of patients with PA with or without OIT, as compared with those of HC subjects, were not anergic and had high T H 2 cytokine production upon peanut-specific restimulation. Conclusions Peanut-specific T R 1 cells can be induced from HC subjects and patients with PA, but those from patients with PA are functionally defective independent of OIT. The unfavorable T R 1/T H 2 ratio is discussed as a possible cause of PA T R 1 cell impairment.

Background Food allergy (FA) can have serious psychosocial and economic repercussions on food-allergic children and their caregivers and be associated with negative effects on their quality of life. Food allergen immunotherapy (IT) is a promising experimental therapy but can be linked to anxiety. This study investigated the effects of IT on FA-specific health-related quality of life (HRQL) over a 24 month-follow-up in caregivers of children with single and multiple food allergies. We hypothesized that characteristics such as age, asthma at baseline and respiratory allergic reactions during therapy were key characteristics that influenced HRQL scores. Methods A validated Food Allergy Quality of Life – Parental Burden Questionnaire (FAQL-PB) was used to assess HRQL. It was randomly distributed to and filled out by caregivers of 57 food-allergic children enrolled in clinical trials of IT. The same parent answered the FABQL-PB questionnaire at baseline and for 6-month, 12- month, 18- month, and 24-month time points on IT. Results Caregiver HRQL improved significantly (change