Clinical trial NCT02961452: Phenotypical Characterization of Peanut Allergic Children
Official title: Phenotypical Characterization of Peanut Allergic Children With Differences in Cross-allergy to Tree Nuts and Other Legumes
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Nut Hypersensitivity
Child
Legumes Allergy
Tree Nut Allergy
Allergy Cross Reaction
Lead sponsor: Lille Catholic University
Sponsor class: OTHER
First posted: 2016-11-11
Enrollment: 317
Sex: ALL
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: CASE_ONLY
Time perspective: RETROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Children with peanut allergy who had a complete evaluation about cross-allergy to Tree Nuts and other legumes

Brief summary: Peanut allergy (PA) has been well studied and its prevalence was estimated up to 1.3% in Europe. Tree nut (TN) allergy and PA are clinically similar and often coexist, TN allergy prevalence ranged from 0.05 to 4.9 %. TN allergy is longlasting and nearly all TN have been associated with fatal allergic reactions . Other legumes or TN also contain seed storage protein orthologs of the globulins (Ara h1, Ara h 3) and 2S albumins (Ara h 2) of peanut, susceptible to provoke allergic reactions, but cross-reactivity to TN and other legumes in PA patients could also appear through primarily sensitization. These possible IgE-binding cross-reactions bring to recommend the avoidance of TN and other legumes which have never been eaten in PA children. In this context, diagnosis work-up of relevant cross-allergy versus asymptomatic cross-sensitization will impact directly children's health-related quality of life (HRQL).

When physicians suspect food allergy, many parameters have to be considered, such as clinical background, clinical history, type of symptoms related to the suspected food and cross-allergy to other foods. Then, to objectively confirm a food allergy and to assess its severity (related to the threshold reactive dose and symptoms), an oral food challenge (OFC) is demanded, and double-blind placebo-controlled food challenge (DBPCFC) is considered as "the gold standard".

Although OFC are more and more available in the diagnosis of PA, the assessment of cross-allergy to every single allergenic TN and legumes requires full allergy work-up and often many years of follow-up. Few studies investigated cross-allergy to TN and other legume, with rates of cross-allergy to TN between 28% and 50%. However, targeting patients with severe or cross-allergic phenotypes would greatly assist the allergist in management and follow-up of PA patients (i.e., planning OFC to cross-reactive food).

Our main objective is to identify different disease phenotypes of PA children with cluster analysis. This statistical approach has never been performed to identify cross-allergic phenotypes. We also will describe cross-allergy in PA and will identify possible risk factors for cross-allergy to TN and other legumes in PA children.


Eligibility criteria: Inclusion Criteria:

* Child evaluated at the allergy Unit of Saint Vincent Hospital of Lille (France) from March 2004 to May 2016
* Peanut allergy proven with a double-blind placebo-controlled food challenge

Exclusion Criteria:

* Patients who had incomplete evaluation for major peanut component at the time of their double-blind placebo-controlled food challenge to peanut.
* All patients refusing Oral Food Challenge.

Primary outcomes:
measure: Double-blind placebo-controlled food challenge Test for determination of type of allergic reaction
timeFrame: at inclusion
measure: Double-blind placebo-controlled food challenge Test for determination of threshold reactive dose
timeFrame: at inclusion
measure: Measure of specific IgEs for the peanut component Ara h 1, Ara h 2, Ara h 3
timeFrame: at inclusion
measure: Oral food challenge test for diagnosis of tree nuts and/or other legumes allergies
timeFrame: through the study completion
Secondary outcomes:
Other outcomes:
Locations:
Study officials:
affiliation: GHICL
name: Mathias Cousin, MD
role: PRINCIPAL_INVESTIGATOR
References: