D1.16 - Molecular sensitization profiles in house dust mite allergic patients from Valencian Community

In Spain house dust mites (HDM) are the second cause of allergic rhinitis after pollen. The genus Dermatophagoides is the most frequent indoor allergen, with more than 30 allergenic components identified by IgE in allergic patients. Dermatophagoides pteronyssinus and farinae group 1 and 2 allergens are recognized as the most sensitizing. However, there are many other allergenic components with variable relevance depending upon the geographic region, patient age and clinical manifestations.

We analyzed the molecular profiling of HDM allergic patients to investigate the correlation with clinical variables and monitor immunotherapy.

Prospective, multicenter observational study carried out in 10 centers from the Valencian Community (Spain). Adult patients allergic to Dermatophagoides (skin test ≥ 3mm and Dermatophagoides-specific serum IgE >0.7 kU/L) were included. Recognition profiles (IgE) of Dermatophagoides molecular components were analyzed by ALEX2 platform (Allergy Xplorer - MADx). Statistical analysis of the variables included: frequency description for qualitative variables and centrality and dispersion for quantitative variables, association tests (Mann Whitney U and Kruskall-Wallis) and multivariate analysis for each variable.

Patients (N=118), median age 29 y (18-37), 53% female, suffering from rhinitis (97%) and asthma (35%). The frequencies of sensitization to Dermatophagoides components were: Der p 2 (83%), Der f 2 (82%), Der p 1 and Der p 23 (75%) and Der p 21 (72%). There were 36 different patterns of cosensitization, the most frequent being those including group 1 and 2 allergens and Der p 23. Der p 5, Der p 7 and Der p 21 were less frequently associated. Multivariate analysis showed a significant association (p<0.05) between specific IgE to male gender (Der p 7, 23), lower age (Group 1 and Der p 7), rhinitis severity (Der p 1, 23), persistence (group 1 & 2) and duration (Der p 5, 7), non-controlled asthma (Der p 5, 20) and less concomitant medication (Der p 7, 23). 

Dermatophagoides sensitization profiling shows intense variability among HDM allergic patients. These parameters may have a role in clinical prognosis and guide immunotherapy prescription and monitoring.