Eosinophilic inflammation in bronchiectasis: a wide-open field for future research

Bronchiectasis is a heterogeneous chronic lung disease, characterised by irreversible dilatation of the airways and attributed to a wide spectrum of other underlying conditions, usually underdiagnosed and inadequately treated with a high burden for both the patients and the healthcare system. The way bronchiectasis is viewed by physicians has drastically changed over the last decades, with the topic of eosinophilia in the context of the disease being one of the substantially highlighted. Eosinophilia was traditionally considered as a means for distinguishing bronchiectasis from asthma, whereas bronchiectasis was primarily associated with neutrophilic inflammation. However, eosinophilic bronchiectasis is nowadays identified as a distinct disease endotype and is associated with a specific clinical course and response to treatment. Further research is needed to better characterise this endotype and improve its personalised investigation and management in daily clinical practice.