Characteristics of the molecular sensitization profiles in patients with birch pollen allergy and cross-reactive food allergy to PR-10 proteins

Abstract

BACKGROUND: Birch pollen allergy is widespread and is the main allergic disease in Russia. Cross-reactive food allergy, often found in patients with birch pollen allergy, is an underestimated problem that complicates the course of pollinosis and requires further study to improve the quality of diagnosis and personalized recommendations for such patients.
 AIM: To study the features of the molecular sensitization profile of adult patients with birch pollen allergy and cross-reactive food allergy to PR-10 proteins.
 MATERIALS AND METHODS: Twenty-five adult patients with confirmed birch pollen allergy, with or without cross-reactive food allergy, were included in an open single-center interventional prospective controlled nonrandomized study. Specific IgE to 112 allergens was determined by multiplex analysis using ImmunoCAP ISAC (ThermoFisher, Sweden). Patients with cross-reactive food allergy completed a validated questionnaire on cross-reactive food allergy symptoms and causative allergens. The primary endpoint of the study was the assessment of the sensitization profile to Bet v 1 and PR-10 proteins (Mal d 1, Ara h 8, Cor a 1.0101, Cor a 1.0401, Act d 8, Api g 1, Pru p 1, and Gly m 4) and the clinical characteristics of the sensitized patients. The secondary endpoint was the comparison of patients with and without cross-reactive food allergy and the evaluation of how sensitization to Bet v 1 and PR-10 homologs can affect clinical manifestations of cross-reactive food allergy in patients.
 RESULTS: The study included 25 patients aged 18–55 years, from which two comparable groups were formed: group 1 consisted of 13 patients with cross-reactive food allergy symptoms and group 2 (without cross-reactive food allergy) consisted of 12 patients who had never experienced cross-reactive food allergy symptoms. Analysis of the sensitization profile to PR-10 allergens revealed similar patterns in both groups; however, sIgE concentrations to all allergens were significantly higher in group 1. A strong correlation was found between the number of triggering products and total IgE level with PR-10 proteins (r=0.81; p=0.001). The severity of cross-reactive food allergy symptoms correlated with the total level of IgE to PR-10 proteins (r=0.97; p 0.0001). The cutoff level for total sIgE to food PR-10 proteins, equal to 70 ISU-E, allowed us to distinguish patients with only oral allergic syndrome from those with systemic manifestations of cross-reactive food allergy.
 CONCLUSION: The results of the study are applicable in clinical practice and have prognostic value in determining the severity of cross-reactive food allergy.