A singleplex IgE test to a mixture of molecules from multiple airborne allergen sources: Innovating in vitro screening of respiratory allergies

Molecular allergy diagnosis enabling personalized medicine

Allergic patients are characterized by complex and patient-specific IgE sensitization profiles to various allergens, which are accompanied by different phenotypes of allergic disease. Molecular allergy diagnosis establishes the patient's IgE reactivity profile at a molecular allergen level and has moved allergology into the era of precision medicine. Molecular allergology started in the late 1980s with the isolation of the first allergen-encoding DNA sequences. Already in 2002, the first allergen microarrays were developed for the assessment of complex IgE sensitization patterns. Recombinant allergens are used for a precise definition of personal IgE reactivity profiles, identification of genuine IgE sensitization to allergen sources for refined prescription of allergen-specific immunotherapy and allergen avoidance diagnosis of co- versus cross-sensitization, epidemiologic studies, and prediction of symptoms, phenotypes, and development of allergic disease. For example, molecular IgE sensitization patterns associated with more severe respiratory allergies, severe food allergy, and allergy to honeybee or vespids are already established. The implementation of molecular allergy diagnosis into daily clinical practice requires continuous medical education and training doctors in molecular allergy diagnosis, and may be facilitated by clinical decision support systems such as diagnostic algorithms that may take advantage of artificial intelligence.

Molecular allergology: a clinical laboratory tool for precision diagnosis, stratification and follow-up of allergic patients

Identification of the molecular culprits of allergic reactions leveraged molecular allergology applications in clinical laboratory medicine. Molecular allergology shifted the focus from complex, heterogeneous allergenic extracts, e.g. pollen, food, or insect venom, towards genetically and immunologically defined proteins available for in vitro diagnosis. Molecular allergology is a precision medicine approach for the diagnosis, stratification, therapeutic management, follow-up and prognostic evaluation of patients within a large range of allergic diseases. Exclusively available for in vitro diagnosis, molecular allergology is nonredundant with any of the current clinical tools for allergy investigation. As an example of a major application, discrimination of genuine sensitization from allergen cross-reactivity at the molecular level allows the proper targeting of the culprit allergen and thus dramatically improves patient management. This review aims at introducing clinical laboratory specialists to molecular allergology, from the biochemical and genetic bases, through immunological concepts, to daily use in the diagnosis and management of allergic diseases.

NOVEOS and ImmunoCAP Have Similar Performances for Diagnosing Food Allergies

BACKGROUND

The clinical significance of newly available platforms for specific IgE measurement must be evaluated. However, data are lacking for NOVEOS (Hycor), especially for food allergens.

OBJECTIVE

We compared the technical and clinical performance of two platforms (ImmunoCAP and NOVEOS) to measure specific IgE to 10 food allergens.

METHODS

Sera from 289 clinically characterized patients were tested for IgE specific for six food allergen extracts (egg white, cow's milk, peanut, hazelnut, fish, and shrimp) and four molecular allergens (Gal d 1, Bos d 8, Ara h 2, and Cor a 14). Specific IgE measurements were carried out using ImmunoCAP and NOVEOS methods. Food allergy diagnoses were established according to international guidelines.

RESULTS

A strong correlation (ρ > 0.9) was present between the two platforms whereas specific IgE concentrations measured with NOVEOS were consistently lower (mean, -15%) than with ImmunoCAP. NOVEOS and ImmunoCAP provided similar overall odds ratios and relative risks for food allergy diagnosis with both allergen extracts and molecular allergens. When all 10 allergens were considered, NOVEOS provided better receiver operating characteristic curves (P = .04). Finally, we found that the most discordant results were observed with hazelnut and peanut extracts and were related to cross-reactive carbohydrate determinants for these two with ImmunoCAP.

CONCLUSIONS

Specific IgE determination by either ImmunoCAP or NOVEOS (odds ratios of allergy, 25.1 or 33.0, respectively) is highly informative regarding the risk of allergy in the selected population. The NOVEOS platform presents the advantage of being less affected by unwanted reactivity owing to carbohydrate determinant-specific IgE while requiring a 10-fold lower test sample volume.