Prospective Registry of Eosinophilia With Respiratory Manifestations With Translational Research Identifying and Characterizing Eosinophils

Introduction: The etiology and therapy of eosinophilic lung diseases are still poorly understood. For individual forms of disease, such as eosinophilic asthma or eosinophilic granulomatosis with polyangiitis (EGPA), new therapeutic approaches exist that block the interleukin IL-5 or the IL-5 receptor. Eosinophilic manifestations of the respiratory tract can exclusively affect the lungs or occur as part of a systemic disease. The manifestations partially overlap and are clinically difficult to differentiate (e.g. eosinophilic asthma, Samter Triad, EGPA or hypereosinophilic syndrome (HES)). It is now known that blood eosinophil counts correlate with the level of eosinophils recruited to the airways. However, it is still unclear whether there is a blood eosinophilia without clinical relevance or whether there is a risk of organ damage (e.g. in HES). Hence, different subtypes of eosinophils with different polarization are discussed. Aim of the study: A registry of patients with eosinophilia and respiratory manifestation will be established at the University Hospital of Innsbruck. The course of disease will be evaluated prospectively in a non-interventional study. This study stands on three main clinical pillars with focus on further characterization of eosinophilic cells: 1. Patients will be included who switch from a previous application of the anti-IL5 antibody mepolizumab (production and administration of the injection from lyophysate through the doctor) to the pre-mixed pen (self-injection at home). 2. Furthermore, special focus is set on patients suffering from the so-called Samter Triad. In these patients, the control of asthma, nasal polyps and NSAID intolerance will be examined in an interdisciplinary fashion during the course of treatment. 3. Previous clinical studies at our Department indicate that some patients with severe eosinophilic asthma or Samter Triad could represent a mono-organic or limited manifestation of lymphoid HES. This hypothesis is tested b