Article

Allergy or tolerance in children sensitized to peanut: prevalence and differentiation using component-resolved diagnostics.

School of Translational Medicine, University of Manchester, NIHR Translational Research Facility in Respiratory Medicine, University Hospital of South Manchester NHS Foundation Trust, Manchester M23 9LT, United Kingdom.
The Journal of allergy and clinical immunology (impact factor: 9.17). 01/2010; 125(1):191-7.e1-13. DOI:10.1016/j.jaci.2009.10.008 pp.191-7.e1-13
Source: PubMed

ABSTRACT Not all peanut-sensitized children develop allergic reactions on exposure.
To establish by oral food challenge the proportion of children with clinical peanut allergy among those considered peanut-sensitized by using skin prick tests and/or IgE measurement, and to investigate whether component-resolved diagnostics using microarray could differentiate peanut allergy from tolerance.
Within a population-based birth cohort, we ascertained peanut sensitization by skin tests and IgE measurement at age 8 years. Among sensitized children, we determined peanut allergy versus tolerance by oral food challenges. We used open challenge among children consuming peanuts (n = 45); others underwent double-blind placebo-controlled challenge (n = 34). We compared sensitization profiles between children with peanut allergy and peanut-tolerant children by using a microarray with 12 pure components (major peanut and potentially cross-reactive components, including grass allergens).
Of 933 children, 110 (11.8%) were peanut-sensitized. Nineteen were not challenged (17 no consent). Twelve with a convincing history of reactions on exposure, IgE > or =15 kUa/L and/or skin test > or =8mm were considered allergic without challenge. Of the remaining 79 children who underwent challenge, 7 had > or =2 objective signs and were designated as having peanut allergy. We estimated the prevalence of clinical peanut allergy among sensitized subjects as 22.4% (95% CI, 14.8% to 32.3%). By using component-resolved diagnostics, we detected marked differences in the pattern of component recognition between children with peanut allergy (n = 29; group enriched with 12 children with allergy) and peanut-tolerant children (n = 52). The peanut component Ara h 2 was the most important predictor of clinical allergy.
The majority of children considered peanut-sensitized on the basis of standard tests do not have peanut allergy. Component-resolved diagnostics may facilitate the diagnosis of peanut allergy.

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Keywords

12 pure components
 
allergic reactions
 
clinical allergy
 
clinical peanut allergy
 
component recognition
 
component-resolved diagnostics
 
considered peanut-sensitized
 
convincing history
 
double-blind placebo-controlled challenge
 
grass allergens
 
IgE measurement
 
open challenge
 
oral food challenge
 
oral food challenges
 
peanut allergy
 
peanut component Ara h 2
 
sensitization profiles
 
skin prick tests
 
skin tests
 
standard tests