Journal of Asthma and Allergy (Jan 2023)
Characteristics of Induced-Sputum Inflammatory Phenotypes in Adults with Asthma: Predictors of Bronchial Eosinophilia
Abstract
Astrid Crespo-Lessmann,1– 3,* Elena Curto,1– 3,* Eder Freddy Mateus Medina,1– 3 Esther Palones,1– 3 Alicia Belda Soler,1– 3 Soraya Sánchez Maza,1– 3 Lorena Soto-Retes,1– 3 Vicente Plaza1– 3 1Servicio de Neumología y Alergia, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain; 2Institut d’Investigació Biomédica Sant Pau, Barcelona, Spain; 3Departament de Medicina, Universitat Autònoma de Barcelona, Barcelona, Spain*These authors contributed equally to this workCorrespondence: Astrid Crespo-Lessmann, Servicio de Neumología y Alergia, Hospital de la Santa Creu i Sant Pau, Carrer Mas Casanovas 90, Barcelona, 08041, Spain, Tel +34-935565972, Fax +34 935565601, Email [email protected]: The objectives of this study were, for patients attending a specialist asthma clinic at a tertiary care hospital, to determine, from sputum induction (SI), proportions of bronchial inflammatory phenotypes, demographic, clinical and functional characteristics of each phenotype, and the most accessible non-invasive inflammatory marker that best discriminates between phenotypes.Patients and Methods: Included were 96 patients with asthma, attending a specialist asthma clinic at a tertiary care hospital, who underwent testing as follows: SI, spirometry, fractional exhaled nitric oxide (FeNO), blood eosinophilia, total immunoglobulin E (IgE), and a skin prick test.Results: SI phenotypes were 46.9% eosinophilic, 33.3% paucigranulocytic, 15.6% neutrophilic, and 4.2% mixed. No significantly different clinical or functional characteristics were observed between the phenotypes. A positive correlation was observed between SI eosinophilia and both emergency visits in the last 12 months (p = 0.041; r = 0.214) and FeNO values (p = 0.000; r = 0.368). Blood eosinophilia correlated with SI eosinophilia (p = 0.001; r = 0.362) and was the best predictor of bronchial eosinophilia, followed by FeNO, and total blood IgE (area under the receiver operating characteristic curve (AUC-ROC) 72%, 65%, and 53%, respectively), although precision was only fair.Conclusion: In consultations for severe asthma, the most frequent phenotype was eosinophilic. Peripheral blood eosinophilia is a reliable marker for discriminating between different bronchial inflammatory phenotypes, is useful in enabling doctors to select a suitable biologic treatment and so prevent asthma exacerbation, and is a better predictor of bronchial eosinophilia than FeNO and IgE values.Keywords: asthma, sputum induction, phenotype, eosinophilia
