Food Allergy as Defined by Component Resolved Diagnosis

Abstract

The diagnosis of food allergy, as assessed by skin tests or in vitro tests with allergen extracts, has insufficient diagnostic performance and needs to be confirmed by food challenges. However, the availability of molecular allergens (recombinant or highly purified) for laboratory methods has profoundly changed the diagnostic approach to food allergy. In fact, the allergy diagnosis conducted at the molecular level, which is defined internationally as component resolved diagnosis (CRD), allows to characterize more precisely the sensitization profile of the individual patient, distinguishing the sensitizations to allergens that are strongly associated with a given source (genuine sensitizers) from those to molecules that are common to many sources (panallergens) or cross-react with other components from the same family or from other families. This review provides an update on the allergen molecules from foods, including plant foods and animal foods, and on the techniques to detect them, by means of a single reagent (singleplex) or an array of molecules tested at the same time (multiplex). Such testing offers detailed information on the sensitization profile of patients and enables the physician to suitably manage their allergy. Moreover, identifying the real causative allergens will be crucial when allergen immunotherapy for food allergy will be introduced in the near future. We also address patents concerning food allergens in this review.

Ovomucoid Specific Immunoglobulin E as a Predictor of Tolerance to Cooked Egg

“…Compared with the EW sIgE level, the ovomucoid sIgE level was a useful but not a superior predictor of cooked egg challenge outcome. Although there is a recent focus on using component-resolved diagnostics to possibly more accurately diagnose food allergies, 12 our study did not support a role for ovomucoid sIgE testing to replace traditional EW sIgE testing in evaluating egg allergy.…”

“…10,11 Component-resolved diagnostics may more accurately diagnose food allergies. 12 Whereas current tests measure sensitization to a group of proteins, component-resolved diagnostics measure sIgE levels to specific egg proteins, for example, ovomucoid.…”

Precision medicine in allergic disease—food allergy, drug allergy, and anaphylaxis—PRACTALL document of the European Academy of Allergy and Clinical Immunology and the American Academy of Allergy, Asthma and Immunology

“…Table provides a list of some of the genes that have been associated with food and drug allergy and anaphylaxis. We are expanding our knowledge of the causative protein components that are responsible for FA, and CRD is being explored as a diagnostic tool for FA . Further, CRD may provide prognostic value and may enable physicians to predict severity of reactions to allergens based on knowledge of the antibodies specific to food‐derived proteins.…”

A Pitfall to Avoid When Using an Allergen Microarray: The Incidental Detection of IgE to Unexpected Allergens

“…1 This technology is currently defined as component-resolved diagnosis (CRD) or molecular-based allergy (MA) diagnostics. [2][3][4][5][6] One major rationale supporting the use of CRD is that most allergic patients are polysensitized (sensitized to >1 allergen), 7 but standard testing regimens using allergen extracts are unable to identify the molecular mechanisms underlying polysensitization. Instead, CRD enables clinicians to generate an IgE sensitization profile for each patient by identifying the specificities of the primary (the original sensitizing molecule) or genuine (causing specific sensitization to their corresponding allergen source) sensitizing allergens and distinguishing these allergens from cross-reactive specificities.…”