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

Abstract

BACKGROUND:

Not all peanut-sensitized children develop allergic reactions on exposure.

OBJECTIVE:

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.

METHODS:

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).

RESULTS:

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.

CONCLUSION:

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.

• Authors: Nicolaos Nicolaou, Maryam Poorafshar, Clare Murray, Angela Simpson, Henric Winell, Gina Kerry, Annika Härlin, Ashley Woodcock, Staffan Ahlstedt, Adnan Custovic
• Journal: The Journal of allergy and clinical immunology (J Allergy Clin Immunol) Vol. 125 Issue 1 Pg. 191-7.e1-13 (Jan 2010) ISSN: 1097-6825 [Electronic] United States
• PMID: 20109746 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright 2010 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

Chemical References

• Immunoglobulin E

Topics

• Arachis (adverse effects, immunology)
• Child
• Cohort Studies
• Double-Blind Method
• Female
• Humans
• Immune Tolerance
• Immunoglobulin E (blood)
• Male
• Peanut Hypersensitivity (diagnosis, epidemiology, immunology)
• Prevalence
• Skin Tests