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

BACKGROUND: Birch pollen allergy is widely spread worldwide and including Russia. Cross-reactive food allergy (CRFA) is an underestimated problem that complicates the course of pollinosis and requires further study. AIMS: To study the features of molecular sensitization profile in adult patients with birch pollen allergy and cross-reactive food allergy to PR-10 proteins. MATERIALS AND METHODS: A total of 25 adult patients with birch pollen allergy, with or without CRFA, were included in an open single-center interventional prospective controlled non-randomized study. Specific IgE to 112 allergens was determined using multiplex analysis ImmunoCAP ISAC. Patients with CRFA filled out a validated questionnaire on CRFA symptoms and causative allergens. The primary endpoint of the study was the assessment of 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, Gly m 4), as well as clinical characteristics of sensitized patients. The secondary endpoint was the comparison of patients with and without CRFA and the evaluation of how sensitization to Bet v 1 and PR-10 homologs can affect clinical manifestations of CRFA in patients. RESULTS: The study included 25 patients aged 18 to 55 years, from which two comparable groups were formed: Group 1 - 13 patients with CRFA symptoms, Group 2 (without CRFA) - 12 patients. When analyzing the sensitization profile to PR-10 allergens, we found similar patterns in both groups, but sIgE concentrations to all allergens were significantly higher in Group 1. We found a strong correlation between the number of triggering products and the total IgE level to PR-10 proteins (r=0.81; p=0.001). The severity of CRFA symptoms correlated with the total level of IgE to PR-10 proteins (r=0.97; p0.0001). The cut-off level for total sIgE to food PR-10 proteins, equal to 70 ISU-E, allowed to distinguish patients with only oral allergic syndrome from patients with systemic manifestations of CRFA. CONCLUSIONS: The obtained results of the study are applicable in clinical practice and have prognostic value in determining the severity of CRFA course.