[Annual review of bronchiectasis in 2021]

Bronchiectasis, a common chronic respiratory disease, is characterized by irreversible and abnormal bronchial dilatation due to multiple causes. In 2021, a series of significant research progress have been made in bronchiectasis, focusing on the mechanism, diagnosis, clinical phenotypes, treatment, comorbidities, etc. Several studies have shown that many mediators are involved in the pathogenesis of bronchiectasis, such as lipids, platelets, and respiratory microorganisms, providing new insights into the development of prevention and therapy targets of bronchiectasis. At the same time, an international expert consensus proposed radiological and clinical diagnosis criteria for inclusion of bronchiectasis patients in clinical trials. Moreover, the proposal of new phenotype, measurement tools and predictors on bronchiectasis, promote the process of individualized therapy for patients. Regarding the clinical trials on bronchiectasis, several important studies have been published, including tobramycin inhalation powder, airway clearance techniques, tiotropium bromide and so forth. In addition, researches on bronchiectasis comorbidities also have new findings. This review summarized the recent published literatures in order to help clinicians better understand bronchiectasis.