Development and Validation of a Sputum Biomarker mRNA Panel for the Diagnostic Work-up of Asthma 1.

The main objectives of the study are 1. to study the different T cell subtypes (Th1, Th2, Th17 and Treg) in the lower airways of healthy subjects and clinically different asthma patients, based on a non-invasive procedure of sputum induction. Patients will be different in function of age, in relation to the trigger (eg aspirin, without or with association with polyposis), without or with underlying atopic sensitization or different in the type of underlying inflammation (eosinophilic vs neutrophilic). This T cell pattern will become the basis of molecular phenotyping in the patients. 2. to study the usefulness of asthma molecular phenotyping (by following the balance between the inflammatory markers on the one hand and the regulatory markers on the other hand) in asthma guidance (longitudinally). The final goal of this project is then to develop a sputum non-invasive biomarker array that can be used to distinguish the different inflammatory asthma phenotypes and that can predict steroid resistance and/or sensitivity to other anti-inflammatory medication, using a non-invasive technique that can be used also at young age and repetitively.