Phenotyping and Classifying Asthma Exacerbations

Rationale: Asthma is a heterogeneous inflammatory respiratory disease affecting 8 - 9% of the European population. Acute asthma exacerbation (AAE) is characterized as an acute worsening of symptoms and is treated inconsistently with steroids with or without antibiotics. In order to adjust and personalise exacerbation treatment, phenotyping and classifying of asthma exacerbations would be required. Therefore, we want to classify patients with AAEs phenotypically in relation to the treatment response. Objective: The primary objective of the study is to determine the relationship between exacerbation treatment response at day 7 and the phenotypical characteristics of asthma exacerbations. Secondary objectives are 1) developing a prediction model based on biomarkers and/or clinical data to predict the treatment response of AAEs 2) comparing the environmental, inflammatory, microbiological and lipid parameters of patients diagnosed with asthma between exacerbation phase and recovery (baseline). Study design: A prospective cohort multicentre study. Study population: Patients aged 12 - 70 years, diagnosed with mild to severe asthma according to the Global Initiative for Asthma (GINA) guidelines. Patients will be included at the onset of a severe asthma exacerbation. Main study parameters/endpoints: Primary endpoint is the relation of phenotypical characteristics with treatment response at day 7, defined by 1) the physician - and patient rated global evaluation of treatment effectiveness (GETE) score 2) difference in Asthma Control Questionnaire 5 (ACQ-5) (\> 0.5) 3) difference in handheld spirometry values like forced expiratory volume (FEV1 ≥ 10%). Treatment response will be classified as excellent, good, moderate or poor. Secondary endpoints are 1) a prediction model for the treatment response of AAE 2) aetiology of the AAE 3) blood and local respiratory parameters; microbiota composition; lipid metabolomics and volatile compounds composition at baseline and AAE.