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Background: Immunoglobulin E (IgE) and immunoglobulin G4 (IgG4) to peanut and its components may influence the clinical reactivity to peanut. Allergen‐specific immunotherapy is known for modifying both IgE and IgG4. Peanut oral immunotherapy may influence these serological parameters. Methods: Exploratory analyses of serological data from participants receiving peanut (Arachis hypogaea) allergen powder‐dnfp (PTAH) and placebo in the double‐blind, randomized, phase 3 PALISADE trial were conducted to evaluate potential relationships between peanut‐specific and peanut component–specific (Ara h 1, Ara h 2, Ara h 3, Ara h 6, Ara h 8, and Ara h 9) IgE and IgG4 levels and clinical outcomes. Results: A total of 269 participants (PTAH, n = 202; placebo, n = 67) were analyzed. No relationship was observed between specific IgE and IgG4 levels at screening and maximum tolerated peanut protein dose during screening or response status during exit double‐blind placebo‐controlled food challenge (DBPCFC). In PTAH‐treated participants, no relationship was observed between IgE and IgG4 levels at screening and maximum symptom severity during exit DBPCFC. Postscreening ratios (ie, postscreening/screening) in the PTAH group were significant at the end of updosing and exit visit for most components. Postscreening changes in specific IgE levels were more pronounced with PTAH versus placebo for most components. Conclusions: Specific IgE and IgG4 levels at screening are not correlated with screening or exit DBPCFC results, and are not predictive of clinical response to PTAH. Peanut (Arachis hypogaea) allergen powder‐dnfp contains the relevant and immunodominant allergens, inducing immunological changes with the treatment. Clinical Trial Registration: ClinicalTrials.gov identifier: NCT02635776. [ABSTRACT FROM AUTHOR]

Background: The benefit of daily administration of Peanut (Arachis hypogaea) Allergen Powder‐dnfp (PTAH)—formerly AR101—has been established in clinical trials, but limited data past the first year of treatment are available. This longitudinal analysis aimed to explore the impact of continued PTAH therapeutic maintenance dosing (300 mg/day) on efficacy, safety/tolerability, and food allergy‐related quality of life. Methods: We present a subset analysis of PALISADE‐ARC004 participants (aged 4–17 years) who received 300 mg PTAH daily for a total of ~1.5 (Group A, n = 110) or ~2 years (Group B, n = 32). Safety assessments included monitoring the incidence of adverse events (AEs), accidental exposures to food allergens, and adrenaline use. Efficacy was assessed by double‐blind, placebo‐controlled food challenge (DBPCFC); skin prick testing; peanut‐specific antibody assays; and Food Allergy Quality of Life Questionnaire (FAQLQ) and Food Allergy Independent Measure (FAIM) scores. Results: Continued maintenance with PTAH increased participants' ability to tolerate peanut protein: 48.1% of completers in Group A (n = 50/104) and 80.8% in Group B (n = 21/26) tolerated 2000 mg peanut protein at exit DBPCFC without dose‐limiting symptoms. Immune biomarkers showed a pattern consistent with treatment‐induced desensitization. Among PTAH‐continuing participants, the overall and treatment‐related exposure‐adjusted AE rate decreased throughout the intervention period in both groups. Clinically meaningful improvements in FAQLQ and FAIM scores over time suggest a potential link between increased desensitization as determined by the DBPCFC and improved quality of life. Conclusions: These results demonstrate that daily PTAH treatment for peanut allergy beyond 1 year leads to an improved safety/tolerability profile and continued clinical and immunological response. [ABSTRACT FROM AUTHOR]

Background: A considerable number of pollen-allergic patients develops allergy to plant foods, which has been attributed to cross-reactivity between food and pollen allergens. The aim of this study was to analyze the differences among pollen-allergic patients with and without plant food allergy. Methods: Eight hundred and six patients were recruited from 8 different hospitals. Each clinical research group included 100 patients (50 plant food-allergic patients and 50 pollen-allergic patients). Diagnosis of pollen allergy was based on typical case history of pollen allergy and positive skin prick tests. Diagnosis of plant-food allergy was based on clear history of plant-food allergy, skin prick tests and/or plant-food challenge tests. A panel of 28 purified allergens from pollens and/or plant foods was used to quantify specific IgE (ADVIA-Centaur® platform). Results: Six hundred and sixty eight patients (83%) of the 806 evaluated had pollen allergy: 396 patients with pollen allergy alone and 272 patients with associated food and pollen allergies. A comparison of both groups showed a statistically significant increase in the food and pollen allergy subgroup in frequency of: (1) asthma (47 vs. 59%; p < 0.001); (2) positive skin test results to several pollens: Plantago,Platanus,Artemisia,Betula,Parietaria and Salsola (p < 0.001); (3) sensitization to purified allergens: Pru p 3, profilin, Pla a 1 – Pla a 2, Sal k 1, PR-10 proteins and Len c 1. Conclusion: Results showed relevant and significant differences between both groups of pollen-allergic patients depending on whether or not they suffered from plant-derived food allergy. Copyright © 2010 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]