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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]

Recurrent upper or lower respiratory symptoms, possibly allergy-related, are very frequent in childhood. It is therefore important that physicians involved in the primary care of these children have an accurate initial diagnostic tool available. In this study, we investigated the value of an in vitro diagnostic device testing 10 common allergens, the ImmunoCAP® Rapid Wheeze/Rhinitis Child, for the primary evaluation of allergy. Children with non-infectious upper or lower respiratory symptoms possibly related to allergy were recruited in the primary health care setting of private practices of physician trained in immunology/allergology. The investigators carried out their usual diagnostic work-up including IgE tests, and the ImmunoCAP® Rapid test was performed with capillary whole blood in a blinded way to the investigator. The investigators’ conclusions on major triggering allergens were compared to the ImmunoCAP® Rapid test results. In the whole patient population (n = 185), the sensitivity of the ImmunoCAP® Rapid test for unveiling allergic disease was 92% (95% CI: 86–96%) and the specificity 97% (95% CI: 86–100%). Current guidelines for allergy diagnosis suggest screening children with recurrent, moderate/severe diseases for allergies. For children with asthma falling into these categories, sensitivity was 100% (95% CI: 88–100%) and specificity 100% (95% CI: 69–100%); for children with moderate and severe rhinitis sensitivity was 93% (95% CI: 86–97%) and the specificity 100% (95% CI: 79–100%). The ImmunoCAP® Rapid test is an accurate test, in particular with regard to high specificity, for diagnosing allergy in children with recurrent respiratory diseases in primary care settings. [ABSTRACT FROM AUTHOR]