Clinical and allergological characteristics of patients with severe bronchial asthma in the regional registry and phenotyping principles for the targeted therapy choice

Abstract

Introduction. Severe asthma targeted therapy effectiveness depends on precise targeting of the selected drug to the key link in pathogenesis. Therefore, severe asthma phenotyping in real clinical practice is relevant.Aim. To determine main clinical and allergological characteristics of patients with severe asthma and to establish important phenotyping signs determined choice of a targeted drug for severe asthma treatment.Materials and methods. The prospective and retrospective study involved patients (n = 198) of the Sverdlovsk region registry receiving targeted therapy of severe asthma. Considering clinical and allergological picture, allergic, non-allergic eosinophilic and mixed severe asthma phenotypes were identified. Clinical and laboratory characteristics of phenotypes were described. A phenotyping algorithm was developed.Results. In the register of patients (n = 198) with severe asthma, non-allergic eosinophilic asthma was 46.5%, allergic – 34.8%, mixed – 18.7%. Significant signs for phenotyping were identified: age of asthma onset, proven allergy, Phadiatop ImmunoCAP level and blood eosinophils on baseline, concomitant allergic rhinitis, chronic rhinosinusitis with nasal polyps and hyper-sensitivity to NSAIDs. The main signs of allergic severe asthma determined: early onset, proven allergy and a positive result of Phadiatop ImmunoCAP (the probability of allergic phenotype increases with Phadiatop ≥ 1.53 PAU/l). Signs of non-allergic eosinophilic asthma were eosinophilia ≥ 150 cells/µl, absence of allergy, concomitant chronic rhinosinusitis with nasal polyps and hypersensitivity to NSAIDs, late onset (after 30 years). Signs were identified for mixed asthma: presence of proven allergy or latent sensitization in combination with high level of Phadiatop ImmunoCAP, late onset, eosinophilia ≥ 300 cells/µl, chronic rhinosinusitis with nasal polyps, hypersensitivity NSAIDs.Conclusions. The algorithm for severe asthma phenotyping based on the isolation of eosinophilia of allergic and non-allergic origin is proposed. Severe asthma phenotyping, which can be carried out in real clinical practice, should facilitate the selection of an initial targeted drug.