Multiplex component‐based allergen microarray in recent clinical studies

Abstract

During the last decades component-resolved diagnostics either as singleplex or multiplex measurements has been introduced into the field of clinical allergology, providing important information that cannot be obtained from extract-based tests. Here we review recent studies that demonstrate clinical applications of the multiplex microarray technique in the diagnosis and risk assessment of allergic patients, and its usefulness in studies of allergic diseases. The usefulness of ImmunoCAP ISAC has been validated in a wide spectrum of allergic diseases like asthma, allergic rhinoconjunctivitis, atopic dermatitis, eosinophilic esophagitis, food allergy and anaphylaxis. ISAC provides a broad picture of a patient's sensitization profile from a single test, and provides information on specific and cross-reactive sensitizations that facilitate diagnosis, risk assessment, and disease management. Furthermore, it can reveal unexpected sensitizations which may explain anaphylaxis previously categorized as idiopathic and also display for the moment clinically non-relevant sensitizations. ISAC can facilitate a better selection of relevant allergens for immunotherapy compared with extract testing. Microarray technique can visualize the allergic march and molecular spreading in the preclinical stages of allergic diseases, and may indicate that the likelihood of developing symptomatic allergy is associated with specific profiles of sensitization to allergen components. ISAC is shown to be a useful tool in routine allergy diagnostics due to its ability to improve risk assessment, to better select relevant allergens for immunotherapy as well as detecting unknown sensitization. Multiplex component testing is especially suitable for patients with complex symptomatology.

Making the Most of In Vitro Tests to Diagnose Food Allergy

“…Multiplex assays may introduce concerns where they reveal sensitization to molecules with potentially no clinical relevance as they are all tested independent of the patient's history. However, multiplex assays can be useful in identifying patterns of sensitization in complex polysensitized patients (eg, patients sensitized to pollen, plant foods, and latex with unclear clinical relevance that are sensitized to a panallergen) and in identifying the culprit allergen in patients with recurrent anaphylaxis 22, 23…”

Serum IgE cross‐reactivity between fish and chicken meats in dogs

“…45 The assessment of IgE reactivity to allergen components of food (the so-called "component-resolved diagnostics") rather than to whole allergen extracts, whose allergen content could be variable, is likely to permit the differentiation between IgE reactivity to food components that initiate systemic allergic responses from those with little allergenic potential and, ultimately, a more accurate diagnosis of food allergy. 46,47 In conclusion, this study provides evidence of serological IgE reactivity of dogs to homologous proteins in C, WF and S. As sera without a firm diagnosis of food allergy were used, however, the clinical relevance of allergenicity of these cross-reactive IgE-binding proteins remains to be determined in dogs with demonstrable signs of allergy upon ingestion of pairs of these food sources.…”

“…Similarly, measurement of IgE reactivity to Ara h 2 was more predictive of peanut allergy than either skin prick testing and specific IgE to whole peanut extract . The assessment of IgE reactivity to allergen components of food (the so‐called “component‐resolved diagnostics”) rather than to whole allergen extracts, whose allergen content could be variable, is likely to permit the differentiation between IgE reactivity to food components that initiate systemic allergic responses from those with little allergenic potential and, ultimately, a more accurate diagnosis of food allergy …”

A summer's tale

“…Park et al have looked at the relationship between the Dermatophagoides farina allergens to which a patient is sensitized and the presence of allergic rhinitis, asthma and/or atopic dermatitis. Sera from 160 children and adults were examined to determine which contained IgE reactivity to each D farina allergen component . Surprisingly, patients with rhinitis and/or asthma were mainly sensitized to the major allergens Der f 1 and Der f 2, whereas those with atopic dermatitis were sensitized to these major components plus one or more minor allergen component (eg, Der f 11, Der f 13, Der f 14, Der f 32 and Der f Alt a 10) (Figure ).…”