The Role of Viral Infection in Acute Exacerbations of Non-cystic Fibrosis Bronchiectasis in Adults

The Role of Viral Infection in Acute Exacerbations of Non-cystic Fibrosis Bronchiectasis in Adults

Bronchiectasis is clinically characterized by irreversible dilation of the bronchi and bronchioles leading to persistent cough, purulent sputum, and airway flow limitation, which may be accompanied by recurrent exacerbations.It has been increasingly recognized that respiratory viruses are mainly responsible for acute exacerbation of chronic pulmonary diseases, i.e. asthma, chronic obstructive pulmonary disease and cystic fibrosis. However,little is known about the roles of viral infection in driving exacerbations of bronchiectasis.This study aims to identify the frequency of common viral infections and determine the roles that viruses play in acute exacerbations of bronchiectasis.

Bronchiectasis is a chronic airway disease characterised by a vicious cycle of persistent bacterial colonization,inflammation and progressive tissue destruction.Patients with bronchiectasis frequently developed acute exacerbations characterised by acute worsening requiring changes in concomitant use of medication,with attendant adverse effects on their morbidity and health-related quality of life. The detailed pathogenesis of exacerbations of bronchiectasis, however, remains poorly understood.

Recent data suggested that airway infection and inflammation are important drivers of exacerbations,therefore the imbalance between chronic bacterial infection and host immune response may result in bronchiectasis exacerbations. Viral infection may be an important factor that leads to this events.It has been established that respiratory viruses are mainly responsible for the exacerbations of other chronic respiratory diseases, i.e. asthma, COPD and cystic fibosis. However, the data regarding prospective studies that sought to investigate the roles of viruses in acute exacerbation of bronchiectasis are lacking. Furthermore,the associations between viruses and bacteria during exacerbation need to be assessed. This study targets at indentifying the frenquency of common viral infections in adults with non-cystic fibrosis bronchiectasis and may shed light on the effects they have on clinical parameters,i.e. the length of exacerbated symptom to recovery,lung function, pulmonary inflammation, bacterial load and quality of life.

Inclusion Criteria:

• Age ≥ 18 years
• HRCT-diagnosed Bronchiectasis
• Capable of providing written informed consent

Exclusion Criteria:

• Patient judged to have poor compliance
• Cystic fibrosis bronchiectasis