New Findings, Pathophysiology, and Antigen Analysis in Pollen-Food Allergy Syndrome

Akiko Yagami; Motohiro Ebisawa


Curr Opin Allergy Clin Immunol. 2019;19(3):218-223. 

In This Article

Allergy Diagnostics

For a long time, the diagnostic procedure for type I allergy has been to evaluate patient symptoms, followed by screening skin prick tests (SPTs) with a panel of respiratory allergens and/or food allergens and conclusive specific IgE testing in the serum of patients. Recently, microarrays of allergen components have significantly improved the ability to show IgE profiles. Mothes-Luksch et al.[14] investigated the data of patients who underwent the usual SPT screening using a panel of 13 inhalant allergens and 7 food allergens followed by ISAC microarray test, and compared with data from patients tested for specific IgE by ISAC microarray first and, depending on the results, skin prick tested with selected allergen extracts only. With all of these observations taken together, the ISAC-first approach followed by fewer SPTs meets the demands for a diagnostic work-up tailored to the patient, and therefore, can be considered equivalent to the conventional method using the SPT as first screening tool, followed by IgE diagnosis.

Heffler et al.[15] evaluated the characteristics of the newly developed Allergy Explorer (ALEX), a macroarray containing both extracted 'whole' allergens and molecular components. They assayed sera from 43 patients with allergies using ALEX and then ImmunoCAP ISAC. Despite differences in the methodology, IgE profiles detected for molecular allergens by ALEX and ISAC were very similar. They concluded that ALEX is a novel tool for describing the IgE profile in a precision medicine setting; in particular, polysensitized patients and patients with PFAS will have a real advantage because of the combination of second-level and third-level allergy diagnostics in the same chip. Although allergen-specific IgE have been considered the only notable serological marker of type 1 hypersensitivity, allergen-specific IgG4 (sIgG4) antibodies are also involved in the immune response resulting from allergen exposure. Smoldovskaya et al.[16] analyzed sIgE and sIgG4 patterns in the most common allergic disorders: bronchial asthma, upper airway disorders, and atopic dermatitis. Among inhalant allergens, the highest adjusted sIgG4 prevalence was observed for the allergens most responsible for sensitization; that is, detectable sIgE production (birch pollen, alder pollen, cat dander, and dog dander). They described that the increased sIgG4 response to pollen allergens among patients with respiratory allergic diseases can be considered a consequence of the fact that sIgG4 response is most common among patients with detectable sIgE and of the features of the sIgE profiles for these pathophysiology, as illustrated by experimental data analysis.